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Cuozzo F, Viloria K, Shilleh AH, Nasteska D, Frazer-Morris C, Tong J, Jiao Z, Boufersaoui A, Marzullo B, Rosoff DB, Smith HR, Bonner C, Kerr-Conte J, Pattou F, Nano R, Piemonti L, Johnson PRV, Spiers R, Roberts J, Lavery GG, Clark A, Ceresa CDL, Ray DW, Hodson L, Davies AP, Rutter GA, Oshima M, Scharfmann R, Merrins MJ, Akerman I, Tennant DA, Ludwig C, Hodson DJ. LDHB contributes to the regulation of lactate levels and basal insulin secretion in human pancreatic β cells. Cell Rep 2024; 43:114047. [PMID: 38607916 DOI: 10.1016/j.celrep.2024.114047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 02/19/2024] [Accepted: 03/19/2024] [Indexed: 04/14/2024] Open
Abstract
Using 13C6 glucose labeling coupled to gas chromatography-mass spectrometry and 2D 1H-13C heteronuclear single quantum coherence NMR spectroscopy, we have obtained a comparative high-resolution map of glucose fate underpinning β cell function. In both mouse and human islets, the contribution of glucose to the tricarboxylic acid (TCA) cycle is similar. Pyruvate fueling of the TCA cycle is primarily mediated by the activity of pyruvate dehydrogenase, with lower flux through pyruvate carboxylase. While the conversion of pyruvate to lactate by lactate dehydrogenase (LDH) can be detected in islets of both species, lactate accumulation is 6-fold higher in human islets. Human islets express LDH, with low-moderate LDHA expression and β cell-specific LDHB expression. LDHB inhibition amplifies LDHA-dependent lactate generation in mouse and human β cells and increases basal insulin release. Lastly, cis-instrument Mendelian randomization shows that low LDHB expression levels correlate with elevated fasting insulin in humans. Thus, LDHB limits lactate generation in β cells to maintain appropriate insulin release.
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Affiliation(s)
- Federica Cuozzo
- Institute of Metabolism and Systems Research (IMSR) and Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham, Birmingham, UK
| | - Katrina Viloria
- Institute of Metabolism and Systems Research (IMSR) and Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham, Birmingham, UK; Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), NIHR Oxford Biomedical Research Centre, Churchill Hospital, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Ali H Shilleh
- Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), NIHR Oxford Biomedical Research Centre, Churchill Hospital, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Daniela Nasteska
- Institute of Metabolism and Systems Research (IMSR) and Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham, Birmingham, UK; Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), NIHR Oxford Biomedical Research Centre, Churchill Hospital, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Charlotte Frazer-Morris
- Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), NIHR Oxford Biomedical Research Centre, Churchill Hospital, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Jason Tong
- Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), NIHR Oxford Biomedical Research Centre, Churchill Hospital, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Zicong Jiao
- Institute of Metabolism and Systems Research (IMSR) and Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham, Birmingham, UK; Geneplus-Beijing, Changping District, Beijing 102206, China
| | - Adam Boufersaoui
- Institute of Metabolism and Systems Research (IMSR) and Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham, Birmingham, UK
| | - Bryan Marzullo
- Institute of Metabolism and Systems Research (IMSR) and Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham, Birmingham, UK
| | - Daniel B Rosoff
- Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), NIHR Oxford Biomedical Research Centre, Churchill Hospital, Radcliffe Department of Medicine, University of Oxford, Oxford, UK; Oxford Kavli Centre for Nanoscience Discovery, University of Oxford, Oxford, UK
| | - Hannah R Smith
- Institute of Metabolism and Systems Research (IMSR) and Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham, Birmingham, UK
| | - Caroline Bonner
- University of Lille, Institut National de la Santé et de la Recherche Médicale (INSERM), Centre Hospitalier Universitaire de Lille (CHU Lille), Institute Pasteur Lille, U1190 -European Genomic Institute for Diabetes (EGID), F59000 Lille, France
| | - Julie Kerr-Conte
- University of Lille, Institut National de la Santé et de la Recherche Médicale (INSERM), Centre Hospitalier Universitaire de Lille (CHU Lille), Institute Pasteur Lille, U1190 -European Genomic Institute for Diabetes (EGID), F59000 Lille, France
| | - Francois Pattou
- University of Lille, Institut National de la Santé et de la Recherche Médicale (INSERM), Centre Hospitalier Universitaire de Lille (CHU Lille), Institute Pasteur Lille, U1190 -European Genomic Institute for Diabetes (EGID), F59000 Lille, France
| | - Rita Nano
- San Raffaele Diabetes Research Institute, IRCCS Ospedale San Raffaele, Milan, Italy; Vita-Salute San Raffaele University, Milan, Italy
| | - Lorenzo Piemonti
- San Raffaele Diabetes Research Institute, IRCCS Ospedale San Raffaele, Milan, Italy; Vita-Salute San Raffaele University, Milan, Italy
| | - Paul R V Johnson
- Nuffield Department of Surgical Sciences, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - Rebecca Spiers
- Nuffield Department of Surgical Sciences, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - Jennie Roberts
- Institute of Metabolism and Systems Research (IMSR) and Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham, Birmingham, UK
| | - Gareth G Lavery
- Institute of Metabolism and Systems Research (IMSR) and Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham, Birmingham, UK; Centre for Systems Health and Integrated Metabolic Research (SHiMR), Department of Biosciences, School of Science and Technology, Nottingham Trent University, Nottingham, UK
| | - Anne Clark
- Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), NIHR Oxford Biomedical Research Centre, Churchill Hospital, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Carlo D L Ceresa
- Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), NIHR Oxford Biomedical Research Centre, Churchill Hospital, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - David W Ray
- Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), NIHR Oxford Biomedical Research Centre, Churchill Hospital, Radcliffe Department of Medicine, University of Oxford, Oxford, UK; Oxford Kavli Centre for Nanoscience Discovery, University of Oxford, Oxford, UK
| | - Leanne Hodson
- Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), NIHR Oxford Biomedical Research Centre, Churchill Hospital, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Amy P Davies
- Section of Cell Biology and Functional Genomics, Division of Diabetes, Endocrinology and Metabolism, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, UK
| | - Guy A Rutter
- Section of Cell Biology and Functional Genomics, Division of Diabetes, Endocrinology and Metabolism, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, UK; CHUM Research Centre and Faculty of Medicine, University of Montreal, Montreal, QC, Canada; Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
| | - Masaya Oshima
- Université Paris Cité, Institut Cochin, INSERM U1016, CNRS UMR 8104, 75014 Paris, France
| | - Raphaël Scharfmann
- Université Paris Cité, Institut Cochin, INSERM U1016, CNRS UMR 8104, 75014 Paris, France
| | - Matthew J Merrins
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Wisconsin-Madison, Madison, WI 53705, USA; William S. Middleton Memorial Veterans Hospital, Madison, WI 53705, USA
| | - Ildem Akerman
- Institute of Metabolism and Systems Research (IMSR) and Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham, Birmingham, UK
| | - Daniel A Tennant
- Institute of Metabolism and Systems Research (IMSR) and Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham, Birmingham, UK.
| | - Christian Ludwig
- Institute of Metabolism and Systems Research (IMSR) and Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham, Birmingham, UK.
| | - David J Hodson
- Institute of Metabolism and Systems Research (IMSR) and Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham, Birmingham, UK; Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), NIHR Oxford Biomedical Research Centre, Churchill Hospital, Radcliffe Department of Medicine, University of Oxford, Oxford, UK.
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2
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Azhar M, Watson LPE, De Lucia Rolfe E, Ferraro M, Carr K, Worsley J, Boesch C, Hodson L, Chatterjee KK, Kemp GJ, Savage DB, Sleigh A. Association of insulin resistance with the accumulation of saturated intramyocellular lipid: A comparison with other fat stores. NMR Biomed 2024:e5117. [PMID: 38356104 DOI: 10.1002/nbm.5117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Revised: 12/19/2023] [Accepted: 01/14/2024] [Indexed: 02/16/2024]
Abstract
It has been shown using proton magnetic resonance spectroscopy (1 H MRS) that, in a group of females, whole-body insulin resistance was more closely related to accumulation of saturated intramyocellular lipid (IMCL) than to IMCL concentration alone. This has not been investigated in males. We investigated whether age- and body mass index-matched healthy males differ from the previously reported females in IMCL composition (measured as CH2 :CH3 ) and IMCL concentration (measured as CH3 ), and in their associations with insulin resistance. We ask whether saturated IMCL accumulation is more strongly associated with insulin resistance than other ectopic and adipose tissue lipid pools and remains a significant predictor when these other pools are taken into account. In this group of males, who had similar overall insulin sensitivity to the females, IMCL was similar between sexes. The males demonstrated similar and even stronger associations of IMCL with insulin resistance, supporting the idea that a marker reflecting the accumulation of saturated IMCL is more strongly associated with whole-body insulin resistance than IMCL concentration alone. However, this marker ceased to be a significant predictor of whole-body insulin resistance after consideration of other lipid pools, which implies that this measure carries no more information in practice than the other predictors we found, such as intrahepatic lipid and visceral adipose tissue. As the marker of saturated IMCL accumulation appears to be related to these two predictors and has a much smaller dynamic range, this finding does not rule out a role for it in the pathogenesis of insulin resistance.
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Affiliation(s)
- Mueed Azhar
- Wolfson Brain Imaging Centre, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Laura P E Watson
- National Institute for Health and Care Research Cambridge Clinical Research Facility, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
- Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK
| | | | - Michele Ferraro
- Wolfson Brain Imaging Centre, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Katherine Carr
- National Institute for Health and Care Research Cambridge Clinical Research Facility, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
| | - Jieniean Worsley
- National Institute for Health and Care Research Cambridge Clinical Research Facility, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
| | - Chris Boesch
- Departments of Clinical Research and Radiology AMSM, University Bern, Bern, Switzerland
| | - Leanne Hodson
- Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), NIHR Oxford Biomedical Research Centre, Churchill Hospital, University of Oxford, Oxford, UK
| | - Krishna K Chatterjee
- National Institute for Health and Care Research Cambridge Clinical Research Facility, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
- Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK
| | - Graham J Kemp
- Department of Musculoskeletal & Ageing Science, University of Liverpool, Liverpool, UK
| | - David B Savage
- Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK
| | - Alison Sleigh
- Wolfson Brain Imaging Centre, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
- National Institute for Health and Care Research Cambridge Clinical Research Facility, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
- Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK
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Murru E, Manca C, Carta G, Ruggiu M, Solinas R, Montisci R, Hodson L, Dearlove D, Mollica MP, Tocco F, Banni S. Indirect Calorimetry-Based Novel Approach for Evaluating Metabolic Flexibility and Its Association with Circulating Metabolic Markers in Middle-Aged Subjects. Nutrients 2024; 16:525. [PMID: 38398849 PMCID: PMC10891777 DOI: 10.3390/nu16040525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Revised: 02/08/2024] [Accepted: 02/08/2024] [Indexed: 02/25/2024] Open
Abstract
We propose a novel method for assessing metabolic flexibility (MF) through indirect calorimetry. A total of twenty healthy volunteers (10 females; 10 males) aged 45-65 were categorized into a Low-Intensity activity group (LI, 0-1 session of 1 h per week) and a High-Intensity activity group (HI, 5-6 sessions of 2 h per week). Volunteers underwent a stepwise exercise test on a cycle ergometer, connected to a calorimeter, to examine respiratory gas exchange to evaluate peak fatty acid Oxidation (PFO) and peak carbohydrate oxidation (PCO). Circulating peroxisome proliferator-activated receptor α (PPARα) biomarkers, docosahexaenoic acid/eicosapentaenoic acid (DHA/EPA) ratio and N-oleoylethanolamine (OEA), and the endocannabinoid- 2-arachidonoylglycerol (2-AG), were evaluated. We developed two MF parameters: the MF index (MFI), calculated by the product of PFO normalized per kg of fat-free mass (FFM) and the percentage of VO2max at PFO, and the peak energy substrates' oxidation (PESO), computed by summing the kilocalories from the PFO and PCO, normalized per kg FFM. The MFI and PESO were significantly different between the HI and LI groups, showing strong correlations with the circulating bioactive substances. Higher DHA/EPA ratio (p ≤ 0.05) and OEA (p ≤ 0.01), but lower 2-AG levels (p ≤ 0.01) were found in the HI group. These new parameters successfully established a functional link between MF and the balance of PPARα/endocannabinoid systems.
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Affiliation(s)
- Elisabetta Murru
- Department of Biomedical Sciences, University of Cagliari, 09042 Monserrato, Italy; (E.M.); (C.M.); (G.C.)
| | - Claudia Manca
- Department of Biomedical Sciences, University of Cagliari, 09042 Monserrato, Italy; (E.M.); (C.M.); (G.C.)
| | - Gianfranca Carta
- Department of Biomedical Sciences, University of Cagliari, 09042 Monserrato, Italy; (E.M.); (C.M.); (G.C.)
| | - Michele Ruggiu
- Clinical Cardiology and Sport Medicine, Department of Medical Science and Public Health, University of Cagliari, 09042 Monserrato, Italy; (M.R.); (R.S.); (R.M.); (F.T.)
| | - Roberto Solinas
- Clinical Cardiology and Sport Medicine, Department of Medical Science and Public Health, University of Cagliari, 09042 Monserrato, Italy; (M.R.); (R.S.); (R.M.); (F.T.)
| | - Roberta Montisci
- Clinical Cardiology and Sport Medicine, Department of Medical Science and Public Health, University of Cagliari, 09042 Monserrato, Italy; (M.R.); (R.S.); (R.M.); (F.T.)
| | - Leanne Hodson
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Headington, Oxford OX3 7LE, UK; (L.H.); (D.D.)
- National Institute for Health Research Oxford Biomedical Research Centre, Oxford University Hospital Trusts, Oxford OX4 2PG, UK
| | - David Dearlove
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Headington, Oxford OX3 7LE, UK; (L.H.); (D.D.)
| | - Maria Pina Mollica
- Department of Biology, University of Naples Federico II, 80126 Naples, Italy;
| | - Filippo Tocco
- Clinical Cardiology and Sport Medicine, Department of Medical Science and Public Health, University of Cagliari, 09042 Monserrato, Italy; (M.R.); (R.S.); (R.M.); (F.T.)
| | - Sebastiano Banni
- Department of Biomedical Sciences, University of Cagliari, 09042 Monserrato, Italy; (E.M.); (C.M.); (G.C.)
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Gamwell JM, Paphiti K, Hodson L, Karpe F, Pinnick KE, Todorčević M. An optimised protocol for the investigation of insulin signalling in a human cell culture model of adipogenesis. Adipocyte 2023; 12:2179339. [PMID: 36763512 PMCID: PMC9980465 DOI: 10.1080/21623945.2023.2179339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Accepted: 02/07/2023] [Indexed: 02/11/2023] Open
Abstract
While there is no standardized protocol for the differentiation of human adipocytes in culture, common themes exist in the use of supra-physiological glucose and hormone concentrations, and an absence of exogenous fatty acids. These factors can have detrimental effects on some aspects of adipogenesis and adipocyte function. Here, we present methods for modifying the adipogenic differentiation protocol to overcome impaired glucose uptake and insulin signalling in human adipose-derived stem cell lines derived from the stromal vascular fraction of abdominal and gluteal subcutaneous adipose tissue. By reducing the length of exposure to adipogenic hormones, in combination with a physiological glucose concentration (5 mM), and the provision of exogenous fatty acids (reflecting typical dietary fatty acids), we were able to restore early insulin signalling events and glucose uptake, which were impaired by extended use of hormones and a high glucose concentration, respectively. Furthermore, the addition of exogenous fatty acids greatly increased the storage of triglycerides and removed the artificial demand to synthesize all fatty acids by de novo lipogenesis. Thus, modifying the adipogenic cocktail can enhance functional aspects of human adipocytes in vitro and is an important variable to consider prior to in vitro investigations into adipocyte biology.
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Affiliation(s)
- Jonathan M. Gamwell
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Churchill Hospital, Headington, UK
| | - Keanu Paphiti
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Churchill Hospital, Headington, UK
| | - Leanne Hodson
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Churchill Hospital, Headington, UK
- NIHR Oxford Biomedical Research Centre, OUH Foundation Trust, Oxford, UK
| | - Fredrik Karpe
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Churchill Hospital, Headington, UK
- NIHR Oxford Biomedical Research Centre, OUH Foundation Trust, Oxford, UK
| | - Katherine E. Pinnick
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Churchill Hospital, Headington, UK
| | - Marijana Todorčević
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Churchill Hospital, Headington, UK
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Luukkonen PK, Porthan K, Ahlholm N, Rosqvist F, Dufour S, Zhang XM, Lehtimäki TE, Seppänen W, Orho-Melander M, Hodson L, Petersen KF, Shulman GI, Yki-Järvinen H. The PNPLA3 I148M variant increases ketogenesis and decreases hepatic de novo lipogenesis and mitochondrial function in humans. Cell Metab 2023; 35:1887-1896.e5. [PMID: 37909034 DOI: 10.1016/j.cmet.2023.10.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 06/26/2023] [Accepted: 10/12/2023] [Indexed: 11/02/2023]
Abstract
The PNPLA3 I148M variant is the major genetic risk factor for all stages of fatty liver disease, but the underlying pathophysiology remains unclear. We studied the effect of this variant on hepatic metabolism in homozygous carriers and non-carriers under multiple physiological conditions with state-of-the-art stable isotope techniques. After an overnight fast, carriers had higher plasma β-hydroxybutyrate concentrations and lower hepatic de novo lipogenesis (DNL) compared to non-carriers. After a mixed meal, fatty acids were channeled toward ketogenesis in carriers, which was associated with an increase in hepatic mitochondrial redox state. During a ketogenic diet, carriers manifested increased rates of intrahepatic lipolysis, increased plasma β-hydroxybutyrate concentrations, and decreased rates of hepatic mitochondrial citrate synthase flux. These studies demonstrate that homozygous PNPLA3 I148M carriers have hepatic mitochondrial dysfunction leading to reduced DNL and channeling of carbons to ketogenesis. These findings have implications for understanding why the PNPLA3 variant predisposes to progressive liver disease.
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Affiliation(s)
- Panu K Luukkonen
- Department of Medicine, Yale School of Medicine, New Haven, CT, USA; Minerva Foundation Institute for Medical Research, Helsinki, Finland; Department of Medicine, University of Helsinki and Helsinki University Hospital, Helsinki, Finland; Abdominal Center, Helsinki University Hospital, Helsinki, Finland.
| | - Kimmo Porthan
- Minerva Foundation Institute for Medical Research, Helsinki, Finland; Department of Medicine, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Noora Ahlholm
- Minerva Foundation Institute for Medical Research, Helsinki, Finland; Department of Medicine, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Fredrik Rosqvist
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford & NIHR Oxford Biomedical Research Centre, Oxford University Hospitals Foundation Trust, Oxford, UK; Department of Public Health and Caring Sciences, Clinical Nutrition and Metabolism, Uppsala University, Uppsala, Sweden
| | - Sylvie Dufour
- Department of Medicine, Yale School of Medicine, New Haven, CT, USA; Yale Diabetes Research Center, Yale School of Medicine, New Haven, CT, USA
| | - Xian-Man Zhang
- Department of Medicine, Yale School of Medicine, New Haven, CT, USA; Yale Diabetes Research Center, Yale School of Medicine, New Haven, CT, USA
| | - Tiina E Lehtimäki
- Department of Radiology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Wenla Seppänen
- Department of Radiology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Marju Orho-Melander
- Department of Clinical Sciences, Diabetes and Endocrinology, University Hospital Malmö, Lund University, Malmö, Sweden
| | - Leanne Hodson
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford & NIHR Oxford Biomedical Research Centre, Oxford University Hospitals Foundation Trust, Oxford, UK
| | - Kitt Falk Petersen
- Department of Medicine, Yale School of Medicine, New Haven, CT, USA; Yale Diabetes Research Center, Yale School of Medicine, New Haven, CT, USA
| | - Gerald I Shulman
- Department of Medicine, Yale School of Medicine, New Haven, CT, USA; Yale Diabetes Research Center, Yale School of Medicine, New Haven, CT, USA; Department of Cellular & Molecular Physiology, Yale School of Medicine, New Haven, CT, USA
| | - Hannele Yki-Järvinen
- Minerva Foundation Institute for Medical Research, Helsinki, Finland; Department of Medicine, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
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Daniels LJ, Kay D, Marjot T, Hodson L, Ray DW. Circadian regulation of liver metabolism: experimental approaches in human, rodent, and cellular models. Am J Physiol Cell Physiol 2023; 325:C1158-C1177. [PMID: 37642240 PMCID: PMC10861179 DOI: 10.1152/ajpcell.00551.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 06/15/2023] [Accepted: 07/19/2023] [Indexed: 08/31/2023]
Abstract
Circadian rhythms are endogenous oscillations with approximately a 24-h period that allow organisms to anticipate the change between day and night. Disruptions that desynchronize or misalign circadian rhythms are associated with an increased risk of cardiometabolic disease. This review focuses on the liver circadian clock as relevant to the risk of developing metabolic diseases including nonalcoholic fatty liver disease (NAFLD), insulin resistance, and type 2 diabetes (T2D). Many liver functions exhibit rhythmicity. Approximately 40% of the hepatic transcriptome exhibits 24-h rhythms, along with rhythms in protein levels, posttranslational modification, and various metabolites. The liver circadian clock is critical for maintaining glucose and lipid homeostasis. Most of the attention in the metabolic field has been directed toward diet, exercise, and rather little to modifiable risks due to circadian misalignment or disruption. Therefore, the aim of this review is to systematically analyze the various approaches that study liver circadian pathways, targeting metabolic liver diseases, such as diabetes, nonalcoholic fatty liver disease, using human, rodent, and cell biology models.NEW & NOTEWORTHY Over the past decade, there has been an increased interest in understanding the intricate relationship between circadian rhythm and liver metabolism. In this review, we have systematically searched the literature to analyze the various experimental approaches utilizing human, rodent, and in vitro cellular approaches to dissect the link between liver circadian rhythms and metabolic disease.
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Affiliation(s)
- Lorna J Daniels
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Danielle Kay
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Thomas Marjot
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Leanne Hodson
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
- NIHR Oxford Biomedical Research Centre, John Radcliffe Hospital, Oxford, United Kingdom
| | - David W Ray
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
- NIHR Oxford Biomedical Research Centre, John Radcliffe Hospital, Oxford, United Kingdom
- Kavli Centre for Nanoscience Discovery, University of Oxford, Oxford, United Kingdom
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7
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Westcott F, Dearlove DJ, Hodson L. Hepatic fatty acid and glucose handling in metabolic disease: Potential impact on cardiovascular disease risk. Atherosclerosis 2023:117237. [PMID: 37633797 DOI: 10.1016/j.atherosclerosis.2023.117237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 08/09/2023] [Accepted: 08/10/2023] [Indexed: 08/28/2023]
Abstract
The prevalence of metabolic diseases, including type 2 diabetes mellitus (T2DM) and metabolic dysfunction-associated steatotic liver disease (MASLD) is increasing. Although invariably associated with obesity, the importance of fat deposition in non-adipose tissue organs has yet to be fully explored. Pathological ectopic fat deposition within the liver (known as (MASLD)) has been suggested to underlie the development of T2DM and is now emerging as an independent risk factor for cardiovascular disease (CVD). The process of hepatic de novo lipogenesis (DNL), that is the synthesis of fatty acids from non-lipid precursors (e.g. glucose), has received much attention as it sits at the intersect of hepatic glucose and fatty acid handling. An upregulation of the DNL pathway has been suggested to be central in the development of metabolic diseases (including MASLD, insulin resistance, and T2DM). Here we review the evidence to determine if hepatic DNL may play a role in the development of MASLD and T2DM and therefore underlie an increased risk of CVD.
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Affiliation(s)
- Felix Westcott
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, UK
| | - David J Dearlove
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, UK
| | - Leanne Hodson
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, UK; Oxford NIHR Biomedical Research Centre, Churchill Hospital, Oxford, UK.
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Marjot T, Tomlinson JW, Hodson L, Ray DW. Timing of energy intake and the therapeutic potential of intermittent fasting and time-restricted eating in NAFLD. Gut 2023; 72:1607-1619. [PMID: 37286229 PMCID: PMC10359613 DOI: 10.1136/gutjnl-2023-329998] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Accepted: 05/14/2023] [Indexed: 06/09/2023]
Abstract
Non-alcoholic fatty liver disease (NAFLD) represents a major public health concern and is associated with a substantial global burden of liver-related and cardiovascular-related morbidity and mortality. High total energy intake coupled with unhealthy consumption of ultra-processed foods and saturated fats have long been regarded as major dietary drivers of NAFLD. However, there is an accumulating body of evidence demonstrating that the timing of energy intake across a the day is also an important determinant of individual risk for NAFLD and associated metabolic conditions. This review summarises the available observational and epidemiological data describing associations between eating patterns and metabolic disease, including the negative effects of irregular meal patterns, skipping breakfast and night-time eating on liver health. We suggest that that these harmful behaviours deserve greater consideration in the risk stratification and management of patients with NAFLD particularly in a 24-hour society with continuous availability of food and with up to 20% of the population now engaged in shiftwork with mistimed eating patterns. We also draw on studies reporting the liver-specific impact of Ramadan, which represents a unique real-world opportunity to explore the physiological impact of fasting. By highlighting data from preclinical and pilot human studies, we present a further biological rationale for manipulating timing of energy intake to improve metabolic health and discuss how this may be mediated through restoration of natural circadian rhythms. Lastly, we comprehensively review the landscape of human trials of intermittent fasting and time-restricted eating in metabolic disease and offer a look to the future about how these dietary strategies may benefit patients with NAFLD and non-alcoholic steatohepatitis.
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Affiliation(s)
- Thomas Marjot
- Oxford Centre for Diabetes Endocrinology and Metabolism, NIHR Oxford Biomedical Research Centre, Churchill Hospital, University of Oxford, Oxford, UK
- Oxford Liver Unit, John Radcliffe Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - Jeremy W Tomlinson
- Oxford Centre for Diabetes Endocrinology and Metabolism, NIHR Oxford Biomedical Research Centre, Churchill Hospital, University of Oxford, Oxford, UK
| | - Leanne Hodson
- Oxford Centre for Diabetes Endocrinology and Metabolism, NIHR Oxford Biomedical Research Centre, Churchill Hospital, University of Oxford, Oxford, UK
| | - David W Ray
- Oxford Centre for Diabetes Endocrinology and Metabolism, NIHR Oxford Biomedical Research Centre, Churchill Hospital, University of Oxford, Oxford, UK
- Sir Jules Thorn Sleep and Circadian Neuroscience Institute, University of Oxford, Oxford, UK
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9
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Nagarajan SR, Livingstone EJ, Monfeuga T, Lewis LC, Ali SHL, Chandran A, Dearlove DJ, Neville MJ, Chen L, Maroteau C, Ruby MA, Hodson L. MLX plays a key role in lipid and glucose metabolism in humans: Evidence from in vitro and in vivo studies. Metabolism 2023; 144:155563. [PMID: 37088121 PMCID: PMC10687193 DOI: 10.1016/j.metabol.2023.155563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 04/13/2023] [Accepted: 04/17/2023] [Indexed: 04/25/2023]
Abstract
BACKGROUND AND AIM Enhanced hepatic de novo lipogenesis (DNL) has been proposed as an underlying mechanism for the development of NAFLD and insulin resistance. Max-like protein factor X (MLX) acts as a heterodimer binding partner for glucose sensing transcription factors and inhibition of MLX or downstream targets has been shown to alleviate intrahepatic triglyceride (IHTG) accumulation in mice. However, its effect on insulin sensitivity remains unclear. As human data is lacking, the aim of the present work was to investigate the role of MLX in regulating lipid and glucose metabolism in primary human hepatocytes (PHH) and in healthy participants with and without MLX polymorphisms. METHODS PHH were transfected with non-targeting or MLX siRNA to assess the effect of MLX knockdown on lipid and glucose metabolism, insulin signalling and the hepatocellular transcriptome. A targeted association analysis on imputed genotype data for MLX on healthy individuals was undertaken to assess associations between specific MLX SNPs (rs665268, rs632758 and rs1474040), plasma biochemistry, IHTG content, DNL and gluconeogenesis. RESULTS MLX knockdown in PHH altered lipid metabolism (decreased DNL (p < 0.05), increased fatty acid oxidation and ketogenesis (p < 0.05), and reduced lipid accumulation (p < 0.001)). Additionally, MLX knockdown increased glycolysis, lactate secretion and glucose production (p < 0.001) and insulin-stimulated pAKT levels (p < 0.01) as assessed by transcriptomic, steady-state and dynamic measurements. Consistent with the in vitro data, individuals with the rs1474040-A and rs632758-C variants had lower fasting plasma insulin (p < 0.05 and p < 0.01, respectively) and TG (p < 0.05 and p < 0.01, respectively). Although there was no difference in IHTG or gluconeogenesis, individuals with rs632758 SNP had notably lower hepatic DNL (p < 0.01). CONCLUSION We have demonstrated using human in vitro and in vivo models that MLX inhibition favored lipid catabolism over anabolism and increased glucose production, despite increased glycolysis and phosphorylation of Akt, suggesting a metabolic mechanism that involves futile cycling.
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Affiliation(s)
- Shilpa R Nagarajan
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Churchill Hospital, Oxford, UK
| | | | - Thomas Monfeuga
- Novo Nordisk Research Centre Oxford, Innovation Building, Oxford, UK
| | - Lara C Lewis
- Novo Nordisk Research Centre Oxford, Innovation Building, Oxford, UK
| | | | | | - David J Dearlove
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Churchill Hospital, Oxford, UK
| | - Matt J Neville
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Churchill Hospital, Oxford, UK; National Institute for Health Research Oxford Biomedical Research Centre, Oxford University Hospital Trusts, UK
| | - Lingyan Chen
- Novo Nordisk Research Centre Oxford, Innovation Building, Oxford, UK
| | - Cyrielle Maroteau
- Novo Nordisk Research Centre Oxford, Innovation Building, Oxford, UK
| | - Maxwell A Ruby
- Novo Nordisk Research Centre Oxford, Innovation Building, Oxford, UK.
| | - Leanne Hodson
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Churchill Hospital, Oxford, UK; National Institute for Health Research Oxford Biomedical Research Centre, Oxford University Hospital Trusts, UK.
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Schulte PA, Jacklitsch BL, Bhattacharya A, Chun H, Edwards N, Elliott KC, Flynn MA, Guerin R, Hodson L, Lincoln JM, MacMahon KL, Pendergrass S, Siven J, Vietas J. Updated assessment of occupational safety and health hazards of climate change. J Occup Environ Hyg 2023; 20:183-206. [PMID: 37104117 PMCID: PMC10443088 DOI: 10.1080/15459624.2023.2205468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Workers, particularly outdoor workers, are among the populations most disproportionately affected by climate-related hazards. However, scientific research and control actions to comprehensively address these hazards are notably absent. To assess this absence, a seven-category framework was developed in 2009 to characterize the scientific literature published from 1988-2008. Using this framework, a second assessment examined the literature published through 2014, and the current one examines literature from 2014-2021. The objectives were to present literature that updates the framework and related topics and increases awareness of the role of climate change in occupational safety and health. In general, there is substantial literature on worker hazards related to ambient temperatures, biological hazards, and extreme weather but less on air pollution, ultraviolet radiation, industrial transitions, and the built environment. There is growing literature on mental health and health equity issues related to climate change, but much more research is needed. The socioeconomic impacts of climate change also require more research. This study illustrates that workers are experiencing increased morbidity and mortality related to climate change. In all areas of climate-related worker risk, including geoengineering, research is needed on the causality and prevalence of hazards, along with surveillance to identify, and interventions for hazard prevention and control.
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Affiliation(s)
- P. A. Schulte
- Advanced Technologies and Laboratories International, Inc, Cincinnati, Ohio
| | - B. L. Jacklitsch
- Centers for Disease Control and Prevention (CDC), National Institute for Occupational Safety and Health (NIOSH), Cincinnati, Ohio
| | - A. Bhattacharya
- Centers for Disease Control and Prevention (CDC), National Institute for Occupational Safety and Health (NIOSH), Cincinnati, Ohio
| | - H. Chun
- Centers for Disease Control and Prevention (CDC), National Center for Emerging and Zoonotic Infectious Diseases (NCEZID), Atlanta, Georgia
| | - N. Edwards
- Centers for Disease Control and Prevention (CDC), National Institute for Occupational Safety and Health (NIOSH), Morgantown, West Virginia
| | - K. C. Elliott
- Centers for Disease Control and Prevention (CDC), National Institute for Occupational Safety and Health (NIOSH), Anchorage, Alaska
| | - M. A. Flynn
- Centers for Disease Control and Prevention (CDC), National Institute for Occupational Safety and Health (NIOSH), Cincinnati, Ohio
| | - R. Guerin
- Centers for Disease Control and Prevention (CDC), National Institute for Occupational Safety and Health (NIOSH), Cincinnati, Ohio
| | - L. Hodson
- Centers for Disease Control and Prevention (CDC), National Institute for Occupational Safety and Health (NIOSH) (retired), Cincinnati, Ohio
| | - J. M. Lincoln
- Centers for Disease Control and Prevention (CDC), National Institute for Occupational Safety and Health (NIOSH), Cincinnati, Ohio
| | - K. L. MacMahon
- Centers for Disease Control and Prevention (CDC), National Institute for Occupational Safety and Health (NIOSH), Cincinnati, Ohio
| | - S. Pendergrass
- Centers for Disease Control and Prevention (CDC), National Institute for Occupational Safety and Health (NIOSH) (retired), Cincinnati, Ohio
| | - J. Siven
- Centers for Disease Control and Prevention (CDC), National Institute for Occupational Safety and Health (NIOSH), Cincinnati, Ohio
| | - J. Vietas
- Centers for Disease Control and Prevention (CDC), National Institute for Occupational Safety and Health (NIOSH), Cincinnati, Ohio
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11
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Lewis LC, Chen L, Hameed LS, Kitchen RR, Maroteau C, Nagarajan SR, Norlin J, Daly CE, Szczerbinska I, Hjuler ST, Patel R, Livingstone EJ, Durrant TN, Wondimu E, BasuRay S, Chandran A, Lee WH, Hu S, Gilboa B, Grandi ME, Toledo EM, Erikat AH, Hodson L, Haynes WG, Pursell NW, Coppieters K, Fleckner J, Howson JM, Andersen B, Ruby MA. Hepatocyte mARC1 promotes fatty liver disease. JHEP Rep 2023; 5:100693. [PMID: 37122688 PMCID: PMC10133763 DOI: 10.1016/j.jhepr.2023.100693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 01/19/2023] [Accepted: 01/21/2023] [Indexed: 05/02/2023] Open
Abstract
Background & Aims Non-alcoholic fatty liver disease (NAFLD) has a prevalence of ∼25% worldwide, with significant public health consequences yet few effective treatments. Human genetics can help elucidate novel biology and identify targets for new therapeutics. Genetic variants in mitochondrial amidoxime-reducing component 1 (MTARC1) have been associated with NAFLD and liver-related mortality; however, its pathophysiological role and the cell type(s) mediating these effects remain unclear. We aimed to investigate how MTARC1 exerts its effects on NAFLD by integrating human genetics with in vitro and in vivo studies of mARC1 knockdown. Methods Analyses including multi-trait colocalisation and Mendelian randomisation were used to assess the genetic associations of MTARC1. In addition, we established an in vitro long-term primary human hepatocyte model with metabolic readouts and used the Gubra Amylin NASH (GAN)-diet non-alcoholic steatohepatitis mouse model treated with hepatocyte-specific N-acetylgalactosamine (GalNAc)-siRNA to understand the in vivo impacts of MTARC1. Results We showed that genetic variants within the MTARC1 locus are associated with liver enzymes, liver fat, plasma lipids, and body composition, and these associations are attributable to the same causal variant (p.A165T, rs2642438 G>A), suggesting a shared mechanism. We demonstrated that increased MTARC1 mRNA had an adverse effect on these traits using Mendelian randomisation, implying therapeutic inhibition of mARC1 could be beneficial. In vitro mARC1 knockdown decreased lipid accumulation and increased triglyceride secretion, and in vivo GalNAc-siRNA-mediated knockdown of mARC1 lowered hepatic but increased plasma triglycerides. We found alterations in pathways regulating lipid metabolism and decreased secretion of 3-hydroxybutyrate upon mARC1 knockdown in vitro and in vivo. Conclusions Collectively, our findings from human genetics, and in vitro and in vivo hepatocyte-specific mARC1 knockdown support the potential efficacy of hepatocyte-specific targeting of mARC1 for treatment of NAFLD. Impact and implications We report that genetically predicted increases in MTARC1 mRNA associate with poor liver health. Furthermore, knockdown of mARC1 reduces hepatic steatosis in primary human hepatocytes and a murine NASH model. Together, these findings further underscore the therapeutic potential of targeting hepatocyte MTARC1 for NAFLD.
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Affiliation(s)
| | | | | | | | | | - Shilpa R. Nagarajan
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Churchill Hospital, Oxford, UK
| | | | | | | | | | - Rahul Patel
- Novo Nordisk Research Centre Oxford, Oxford, UK
| | | | | | | | | | | | - Wan-Hung Lee
- Dicerna Pharmaceuticals Inc., Lexington, MA, USA
| | - Sile Hu
- Novo Nordisk Research Centre Oxford, Oxford, UK
| | | | | | | | | | - Leanne Hodson
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Churchill Hospital, Oxford, UK
- National Institute for Health Research Oxford Biomedical Research Centre, Oxford University Hospital Trusts, Oxford, UK
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12
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Savic D, Mózes FE, Green PG, Burrage MK, Kjaer MS, Hodson L, Neubauer S, Pavlides M, Valkovič L. Detection and alterations of acetylcarnitine (AC) in human liver by 1 H MRS at 3T after supplementation with l-carnitine. Magn Reson Med 2023; 89:1314-1322. [PMID: 36573435 DOI: 10.1002/mrm.29544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Revised: 10/24/2022] [Accepted: 11/14/2022] [Indexed: 12/28/2022]
Abstract
PURPOSE Acetylcarnitine can be assessed in vivo using proton MRS (1 H-MRS) with long TEs and this has been previously applied successfully in muscle. The aim of this study was to evaluate a 1 H-MRS technique for liver acetylcarnitine quantification in healthy humans before and after l-carnitine supplementation. METHOD Baseline acetylcarnitine levels were quantified using a STEAM sequence with prolonged TE in 15 healthy adults. Using STEAM with four different TEs was evaluated in phantoms. To assess reproducibility of the measurements, five of the participants had repeated 1 H-MRS without receiving l-carnitine supplementation. To determine if liver acetylcarnitine could be changed after l-carnitine supplementation, acetylcarnitine was quantified 2 h after intravenous l-carnitine supplementation (50 mg/kg body weight) in the other 10 participants. Hepatic lipids were also quantified from the 1 H-MRS spectra. RESULTS There was good separation between the acetylcarnitine and fat in the phantoms using TE = 100 ms. Hepatic acetylcarnitine levels were reproducible (coefficient of reproducibility = 0.049%) and there was a significant (p < 0.001) increase in the relative abundance after a single supplementation of l-carnitine. Hepatic allylic, methyl, and methylene peaks were not altered by l-carnitine supplementation in healthy volunteers. CONCLUSION Our results demonstrate that our 1 H-MRS technique could be used to measure acetylcarnitine in the liver and detect changes following intravenous supplementation in healthy adults despite the presence of lipids. Our techniques should be explored further in the study of fatty liver disease, where acetylcarnitine is suggested to be altered due to hepatic inflexibilities.
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Affiliation(s)
- Dragana Savic
- The Oxford Centre for Clinical Magnetic Resonance Research (OCMR), Radcliffe Department of Medicine, University of Oxford, Oxford, UK
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Oxford, UK
| | - Ferenc E Mózes
- The Oxford Centre for Clinical Magnetic Resonance Research (OCMR), Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Peregrine G Green
- The Oxford Centre for Clinical Magnetic Resonance Research (OCMR), Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Matthew K Burrage
- The Oxford Centre for Clinical Magnetic Resonance Research (OCMR), Radcliffe Department of Medicine, University of Oxford, Oxford, UK
- Faculty of Medicine, University of Queensland, St Lucia, Queensland, Australia
| | | | - Leanne Hodson
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Oxford, UK
- Oxford NIHR Biomedical Research Centre, University of Oxford, Oxford, UK
| | - Stefan Neubauer
- The Oxford Centre for Clinical Magnetic Resonance Research (OCMR), Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Michael Pavlides
- The Oxford Centre for Clinical Magnetic Resonance Research (OCMR), Radcliffe Department of Medicine, University of Oxford, Oxford, UK
- Oxford NIHR Biomedical Research Centre, University of Oxford, Oxford, UK
- Translational Gastroenterology Unit, University of Oxford, Oxford, UK
| | - Ladislav Valkovič
- The Oxford Centre for Clinical Magnetic Resonance Research (OCMR), Radcliffe Department of Medicine, University of Oxford, Oxford, UK
- Department of Imaging Methods, Institute of Measurement Science, Slovak Academy of Sciences, Bratislava, Slovakia
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13
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Abstract
PURPOSE OF REVIEW De novo lipogenesis (DNL) is a metabolic process occurring mainly within the liver, in humans. Insulin is a primary signal for promoting DNL; thus, nutritional state is a key determinant for upregulation of the pathway. However, the effects of dietary macronutrient composition on hepatic DNL remain unclear. Nor is it clear if a nutrition-induced increase in DNL results in accumulation of intra-hepatic triglyceride (IHTG); a mechanism often proposed for pathological IHTG. Here, we review the latest evidence surrounding the nutritional regulation of hepatic DNL. RECENT FINDINGS The role of carbohydrate intake on hepatic DNL regulation has been well studied, with only limited data on the effects of fats and proteins. Overall, increasing carbohydrate intake typically results in an upregulation of DNL, with fructose being more lipogenic than glucose. For fat, it appears that an increased intake of n-3 polyunsaturated fatty acids downregulates DNL, whilst, in contrast, an increased dietary protein intake may upregulate DNL. SUMMARY Although DNL is upregulated with high-carbohydrate or mixed-macronutrient meal consumption, the effects of fat and protein remain unclear. Additionally, the effects of different phenotypes (including sex, age, ethnicity, and menopause status) in combination with different diets (enriched in different macronutrients) on hepatic DNL requires elucidation.
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Affiliation(s)
- Eloise Cross
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford
| | - David J Dearlove
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford
| | - Leanne Hodson
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford
- Oxford NIHR Biomedical Research Centre, Churchill Hospital, Oxford, UK
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14
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Othonos N, Pofi R, Arvaniti A, White S, Bonaventura I, Nikolaou N, Moolla A, Marjot T, Stimson RH, van Beek AP, van Faassen M, Isidori AM, Bateman E, Sadler R, Karpe F, Stewart PM, Webster C, Duffy J, Eastell R, Gossiel F, Cornfield T, Hodson L, Jane Escott K, Whittaker A, Kirik U, Coleman RL, Scott CAB, Milton JE, Agbaje O, Holman RR, Tomlinson JW. 11β-HSD1 inhibition in men mitigates prednisolone-induced adverse effects in a proof-of-concept randomised double-blind placebo-controlled trial. Nat Commun 2023; 14:1025. [PMID: 36823106 PMCID: PMC9950480 DOI: 10.1038/s41467-023-36541-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Accepted: 02/06/2023] [Indexed: 02/25/2023] Open
Abstract
Glucocorticoids prescribed to limit inflammation, have significant adverse effects. As 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) regenerates active glucocorticoid, we investigated whether 11β-HSD1 inhibition with AZD4017 could mitigate adverse glucocorticoid effects without compromising their anti-inflammatory actions. We conducted a proof-of-concept, randomized, double-blind, placebo-controlled study at Research Unit, Churchill Hospital, Oxford, UK (NCT03111810). 32 healthy male volunteers were randomized to AZD4017 or placebo, alongside prednisolone treatment. Although the primary endpoint of the study (change in glucose disposal during a two-step hyperinsulinemic, normoglycemic clamp) wasn't met, hepatic insulin sensitivity worsened in the placebo-treated but not in the AZD4017-treated group. Protective effects of AZD4017 on markers of lipid metabolism and bone turnover were observed. Night-time blood pressure was higher in the placebo-treated but not in the AZD4017-treated group. Urinary (5aTHF+THF)/THE ratio was lower in the AZD4017-treated but remained the same in the placebo-treated group. Most anti-inflammatory actions of prednisolone persisted with AZD4017 co-treatment. Four adverse events were reported with AZD4017 and no serious adverse events. Here we show that co-administration of AZD4017 with prednisolone in men is a potential strategy to limit adverse glucocorticoid effects.
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Affiliation(s)
- Nantia Othonos
- Oxford Centre for Diabetes, Endocrinology and Metabolism, NIHR Oxford Biomedical Research Centre, University of Oxford, Churchill Hospital, Oxford, OX3 7LE, UK
| | - Riccardo Pofi
- Oxford Centre for Diabetes, Endocrinology and Metabolism, NIHR Oxford Biomedical Research Centre, University of Oxford, Churchill Hospital, Oxford, OX3 7LE, UK
- Department of Experimental Medicine, Sapienza University of Rome, Viale Regina Elena, 324, 00161, Rome, Italy
| | - Anastasia Arvaniti
- Oxford Centre for Diabetes, Endocrinology and Metabolism, NIHR Oxford Biomedical Research Centre, University of Oxford, Churchill Hospital, Oxford, OX3 7LE, UK
- Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, OX3 0BP, UK
| | - Sarah White
- Oxford Centre for Diabetes, Endocrinology and Metabolism, NIHR Oxford Biomedical Research Centre, University of Oxford, Churchill Hospital, Oxford, OX3 7LE, UK
| | - Ilaria Bonaventura
- Oxford Centre for Diabetes, Endocrinology and Metabolism, NIHR Oxford Biomedical Research Centre, University of Oxford, Churchill Hospital, Oxford, OX3 7LE, UK
- Department of Experimental Medicine, Sapienza University of Rome, Viale Regina Elena, 324, 00161, Rome, Italy
| | - Nikolaos Nikolaou
- Oxford Centre for Diabetes, Endocrinology and Metabolism, NIHR Oxford Biomedical Research Centre, University of Oxford, Churchill Hospital, Oxford, OX3 7LE, UK
| | - Ahmad Moolla
- Oxford Centre for Diabetes, Endocrinology and Metabolism, NIHR Oxford Biomedical Research Centre, University of Oxford, Churchill Hospital, Oxford, OX3 7LE, UK
| | - Thomas Marjot
- Oxford Centre for Diabetes, Endocrinology and Metabolism, NIHR Oxford Biomedical Research Centre, University of Oxford, Churchill Hospital, Oxford, OX3 7LE, UK
- Translational Gastroenterology Unit, NIHR Oxford Biomedical Research Centre, University of Oxford, John Radcliffe Hospital, Oxford, OX3 9DU, UK
| | - Roland H Stimson
- University/BHF Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, EH16 4TJ, UK
| | - André P van Beek
- Department of Endocrinology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Martijn van Faassen
- Department of Laboratory Medicine, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Andrea M Isidori
- Department of Experimental Medicine, Sapienza University of Rome, Viale Regina Elena, 324, 00161, Rome, Italy
| | | | - Ross Sadler
- Department of Immunology, Churchill Hospital, Oxford, OX3 7LE, UK
| | - Fredrik Karpe
- Oxford Centre for Diabetes, Endocrinology and Metabolism, NIHR Oxford Biomedical Research Centre, University of Oxford, Churchill Hospital, Oxford, OX3 7LE, UK
| | - Paul M Stewart
- Faculty of Medicine & Health, University of Leeds, Clarendon Way, Leeds, LS2 9NL, UK
| | - Craig Webster
- Department of Pathology, University Hospitals Birmingham, NHS Foundation Trust, Birmingham, B15 2GW, UK
| | - Joanne Duffy
- Department of Pathology, University Hospitals Birmingham, NHS Foundation Trust, Birmingham, B15 2GW, UK
| | - Richard Eastell
- Mellanby Centre for Musculoskeletal Research, Department of Oncology & Metabolism, Faculty of Medicine, Dentistry & Health, University of Sheffield, Sheffield, SR10 2RX, UK
| | - Fatma Gossiel
- Mellanby Centre for Musculoskeletal Research, Department of Oncology & Metabolism, Faculty of Medicine, Dentistry & Health, University of Sheffield, Sheffield, SR10 2RX, UK
| | - Thomas Cornfield
- Oxford Centre for Diabetes, Endocrinology and Metabolism, NIHR Oxford Biomedical Research Centre, University of Oxford, Churchill Hospital, Oxford, OX3 7LE, UK
| | - Leanne Hodson
- Oxford Centre for Diabetes, Endocrinology and Metabolism, NIHR Oxford Biomedical Research Centre, University of Oxford, Churchill Hospital, Oxford, OX3 7LE, UK
| | - K Jane Escott
- Business Development & Licensing, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK
| | - Andrew Whittaker
- Emerging Innovations Unit, Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK
| | - Ufuk Kirik
- Quantitative Biology, Discovery Sciences, BioPharmaceuticals R&D AstraZeneca, Mölndal, Sweden
| | - Ruth L Coleman
- Oxford Centre for Diabetes, Endocrinology and Metabolism, NIHR Oxford Biomedical Research Centre, University of Oxford, Churchill Hospital, Oxford, OX3 7LE, UK
- Diabetes Trials Unit, Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, Oxford, OX3 7LJ, UK
| | - Charles A B Scott
- Oxford Centre for Diabetes, Endocrinology and Metabolism, NIHR Oxford Biomedical Research Centre, University of Oxford, Churchill Hospital, Oxford, OX3 7LE, UK
- Diabetes Trials Unit, Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, Oxford, OX3 7LJ, UK
| | - Joanne E Milton
- Oxford Centre for Diabetes, Endocrinology and Metabolism, NIHR Oxford Biomedical Research Centre, University of Oxford, Churchill Hospital, Oxford, OX3 7LE, UK
- Diabetes Trials Unit, Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, Oxford, OX3 7LJ, UK
| | - Olorunsola Agbaje
- Oxford Centre for Diabetes, Endocrinology and Metabolism, NIHR Oxford Biomedical Research Centre, University of Oxford, Churchill Hospital, Oxford, OX3 7LE, UK
- Diabetes Trials Unit, Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, Oxford, OX3 7LJ, UK
| | - Rury R Holman
- Oxford Centre for Diabetes, Endocrinology and Metabolism, NIHR Oxford Biomedical Research Centre, University of Oxford, Churchill Hospital, Oxford, OX3 7LE, UK
- Diabetes Trials Unit, Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, Oxford, OX3 7LJ, UK
| | - Jeremy W Tomlinson
- Oxford Centre for Diabetes, Endocrinology and Metabolism, NIHR Oxford Biomedical Research Centre, University of Oxford, Churchill Hospital, Oxford, OX3 7LE, UK.
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15
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Nagarajan SR, Cross E, Johnson E, Sanna F, Daniels LJ, Ray DW, Hodson L. Determining the temporal, dose, and composition effects of nutritional substrates in an in vitro model of intrahepatocellular triglyceride accumulation. Physiol Rep 2022; 10:e15463. [PMID: 36301719 PMCID: PMC9612139 DOI: 10.14814/phy2.15463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 07/29/2022] [Accepted: 08/24/2022] [Indexed: 12/02/2022] Open
Abstract
Pathological accumulation of intrahepatic triglyceride underpins the early stages of nonalcoholic fatty liver disease (NAFLD) and can progress to fibrosis, cirrhosis, and cancer of the liver. Studies in humans suggest that consumption of a diet enriched in saturated compared to unsaturated fatty acids (FAs), is more detrimental to liver fat accumulation and metabolism. However, the reasons for the divergence remain unclear and physiologically-relevant cellular models are required. Therefore, the aims of this study were to investigate the effect of modifying media composition, concentration, and treatment frequency of sugars, FAs and insulin on intrahepatocellular triglyceride content and intracellular glucose, FA and circadian function. Huh7 cells were treated with 2% human serum and a combination of sugars and FAs (low fat low sugar [LFLS], high fat low sugar [HFLS], or high fat high sugar [HFHS]) enriched in either unsaturated (OPLA) or saturated (POLA) FAs for 2, 4, or 7 days with a daily or alternating treatment regime. Stable isotope tracers were utilized to investigate basal and/or insulin-responsive changes in hepatocyte metabolism in response to different treatment regimes. Cell viability, media biochemistry, intracellular metabolism, and circadian biology were quantified. The FA composition of the media (OPLA vs. POLA) did not influence cell viability or intracellular triglyceride content in hepatocytes. In contrast, POLA-treated cells had lower FA oxidation and media acetate, and with higher FA concentrations, displayed lower intracellular glycogen content and diminished insulin stimulation of glycogenesis, compared to OPLA-treated cells. The addition of HFHS also had profound effects on circadian oscillation and gene expression. Cells treated daily with HFHS for at least 4 days resulted in a cellular model displaying characteristics of early stage NAFLD seen in humans. Repeated treatment for longer durations (≥7 days) may provide opportunities to investigate lipid and glucose metabolism in more severe stages of NAFLD.
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Affiliation(s)
- Shilpa R. Nagarajan
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of MedicineChurchill Hospital, University of OxfordOxfordUK
| | - Eloise Cross
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of MedicineChurchill Hospital, University of OxfordOxfordUK
| | - Elspeth Johnson
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of MedicineChurchill Hospital, University of OxfordOxfordUK
| | - Fabio Sanna
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of MedicineChurchill Hospital, University of OxfordOxfordUK
| | - Lorna J. Daniels
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of MedicineChurchill Hospital, University of OxfordOxfordUK
| | - David W. Ray
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of MedicineChurchill Hospital, University of OxfordOxfordUK
- National Institute for Health Research Oxford Biomedical Research CentreOxford University Hospital TrustsOxfordUK
| | - Leanne Hodson
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of MedicineChurchill Hospital, University of OxfordOxfordUK
- National Institute for Health Research Oxford Biomedical Research CentreOxford University Hospital TrustsOxfordUK
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16
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Pramfalk C, Ahmed O, Pedrelli M, Minniti ME, Luquet S, Denis RG, Olin M, Härdfeldt J, Vedin LL, Steffensen KR, Rydén M, Hodson L, Eriksson M, Parini P. Soat2 ties cholesterol metabolism to β-oxidation and glucose tolerance in male mice. J Intern Med 2022; 292:296-307. [PMID: 34982494 DOI: 10.1111/joim.13450] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
BACKGROUND Sterol O-acyltransferase 2 (Soat2) encodes acyl-coenzyme A:cholesterol acyltransferase 2 (ACAT2), which synthesizes cholesteryl esters in hepatocytes and enterocytes fated either to storage or to secretion into nascent triglyceride-rich lipoproteins. OBJECTIVES We aimed to unravel the molecular mechanisms leading to reduced hepatic steatosis when Soat2 is depleted in mice. METHODS Soat2-/- and wild-type mice were fed a high-fat, a high-carbohydrate, or a chow diet, and parameters of lipid and glucose metabolism were assessed. RESULTS Glucose, insulin, homeostatic model assessment for insulin resistance (HOMA-IR), oral glucose tolerance (OGTT), and insulin tolerance tests significantly improved in Soat2-/- mice, irrespective of the dietary regimes (2-way ANOVA). The significant positive correlations between area under the curve (AUC) OGTT (r = 0.66, p < 0.05), serum fasting insulin (r = 0.86, p < 0.05), HOMA-IR (r = 0.86, p < 0.05), Adipo-IR (0.87, p < 0.05), hepatic triglycerides (TGs) (r = 0.89, p < 0.05), very-low-density lipoprotein (VLDL)-TG (r = 0.87, p < 0.05) and the hepatic cholesteryl esters in wild-type mice disappeared in Soat2-/- mice. Genetic depletion of Soat2 also increased whole-body oxidation by 30% (p < 0.05) compared to wild-type mice. CONCLUSION Our data demonstrate that ACAT2-generated cholesteryl esters negatively affect the metabolic control by retaining TG in the liver and that genetic inhibition of Soat2 improves liver steatosis via partitioning of lipids into secretory (VLDL-TG) and oxidative (fatty acids) pathways.
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Affiliation(s)
- Camilla Pramfalk
- Cardio Metabolic Unit, Department of Medicine and Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden
- Medicine Unit Endocrinology, Theme Inflammation and Ageing, Karolinska University Hospital, Stockholm, Sweden
| | - Osman Ahmed
- Cardio Metabolic Unit, Department of Medicine and Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden
- Department of Biochemistry, Faculty of Medicine, Khartoum University, Khartoum, Sudan
| | - Matteo Pedrelli
- Cardio Metabolic Unit, Department of Medicine and Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Mirko E Minniti
- Cardio Metabolic Unit, Department of Medicine and Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden
| | | | | | - Maria Olin
- Cardio Metabolic Unit, Department of Medicine and Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Jennifer Härdfeldt
- Cardio Metabolic Unit, Department of Medicine and Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Lise-Lotte Vedin
- Cardio Metabolic Unit, Department of Medicine and Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Knut R Steffensen
- Cardio Metabolic Unit, Department of Medicine and Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Mikael Rydén
- Medicine Unit Endocrinology, Theme Inflammation and Ageing, Karolinska University Hospital, Stockholm, Sweden
- Unit of Endocrinology, Department of Medicine, Karolinska Institutet at Karolinska University Hospital Huddinge, Stockholm, Sweden
| | - Leanne Hodson
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
- National Institute for Health Research Oxford Biomedical Research Centre, Oxford University Hospital Trusts, Oxford, UK
| | - Mats Eriksson
- Medicine Unit Endocrinology, Theme Inflammation and Ageing, Karolinska University Hospital, Stockholm, Sweden
- Unit of Endocrinology, Department of Medicine, Karolinska Institutet at Karolinska University Hospital Huddinge, Stockholm, Sweden
| | - Paolo Parini
- Cardio Metabolic Unit, Department of Medicine and Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden
- Medicine Unit Endocrinology, Theme Inflammation and Ageing, Karolinska University Hospital, Stockholm, Sweden
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Abstract
PURPOSE OF REVIEW Intrahepatic triglyceride (IHTG) content is determined by substrate flux to, fatty acid synthesis and partitioning within, and triglyceride disposal from the liver. Dysregulation of these processes may cause IHTG accumulation, potentially leading to nonalcoholic fatty liver disease. The aetiology of IHTG accumulation has not been fully elucidated; however, environmental factors and heritability are important. Here, we review recent evidence regarding the contribution of metabolic and genetic components of IHTG accumulation. RECENT FINDINGS Obesity and insulin resistance are the primary metabolic drivers for IHTG accumulation. These risk factors have pronounced and seemingly overlapping effects on all processes involved in determining IHTG content. The strong and interchangeable associations between obesity, insulin resistance and IHTG make it challenging to determine their relative contributions. Genome-wide association studies have identified a growing list of single nucleotide polymorphisms associated with IHTG content and recent work has begun to elucidate their mechanistic effects. The mechanisms underlying metabolic and genetic drivers of IHTG appear to be distinct. SUMMARY Both metabolic and genetic factors influence IHTG content by apparently distinct mechanisms. Further work is needed to determine metabolic and genetic interaction effects, which may lead to more personalized and potentially efficacious therapeutic interventions. The development of a comprehensive polygenic risk score for IHTG content may help facilitate this.
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Affiliation(s)
- David J Dearlove
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford
| | - Leanne Hodson
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford
- Oxford NIHR Biomedical Research Centre, Churchill Hospital, Oxford, UK
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18
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Hazlehurst JM, Lim TR, Charlton C, Miller JJ, Gathercole LL, Cornfield T, Nikolaou N, Harris SE, Moolla A, Othonos N, Heather LC, Marjot T, Tyler DJ, Carr C, Hodson L, McKeating J, Tomlinson JW. Acute intermittent hypoxia drives hepatic de novo lipogenesis in humans and rodents. Metabol Open 2022; 14:100177. [PMID: 35313531 PMCID: PMC8933516 DOI: 10.1016/j.metop.2022.100177] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 03/12/2022] [Indexed: 02/09/2023] Open
Abstract
Background and aims Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver condition. It is tightly associated with an adverse metabolic phenotype (including obesity and type 2 diabetes) as well as with obstructive sleep apnoea (OSA) of which intermittent hypoxia is a critical component. Hepatic de novo lipogenesis (DNL) is a significant contributor to hepatic lipid content and the pathogenesis of NAFLD and has been proposed as a key pathway to target in the development of pharmacotherapies to treat NAFLD. Our aim is to use experimental models to investigate the impact of hypoxia on hepatic lipid metabolism independent of obesity and metabolic disease. Methods Human and rodent studies incorporating stable isotopes and hyperinsulinaemic euglycaemic clamp studies were performed to assess the regulation of DNL and broader metabolic phenotype by intermittent hypoxia. Cell-based studies, including pharmacological and genetic manipulation of hypoxia-inducible factors (HIF), were used to examine the underlying mechanisms. Results Hepatic DNL increased in response to acute intermittent hypoxia in humans, without alteration in glucose production or disposal. These observations were endorsed in a prolonged model of intermittent hypoxia in rodents using stable isotopic assessment of lipid metabolism. Changes in DNL were paralleled by increases in hepatic gene expression of acetyl CoA carboxylase 1 and fatty acid synthase. In human hepatoma cell lines, hypoxia increased both DNL and fatty acid uptake through HIF-1α and -2α dependent mechanisms. Conclusions These studies provide robust evidence linking intermittent hypoxia and the regulation of DNL in both acute and sustained in vivo models of intermittent hypoxia, providing an important mechanistic link between hypoxia and NAFLD.
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Affiliation(s)
- Jonathan M. Hazlehurst
- Oxford Centre for Diabetes, Endocrinology and Metabolism, NIHR Oxford Biomedical Research Centre, University of Oxford, Churchill Hospital, Oxford, OX3 7LE, UK
- Institute of Metabolism and Systems Research, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
- Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, B15 2TT, UK
- Department of Diabetes and Endocrinology, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
| | - Teegan Reina Lim
- Department of Gastro & Hepatology, Singapore General Hospital, Outram Road, 544894, Singapore
| | - Catriona Charlton
- Oxford Centre for Diabetes, Endocrinology and Metabolism, NIHR Oxford Biomedical Research Centre, University of Oxford, Churchill Hospital, Oxford, OX3 7LE, UK
| | - Jack J. Miller
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, OX1 3PT, UK
- Oxford Centre for Clinical Magnetic Resonance Research, Division of Cardiovascular Medicine, University of Oxford, Oxford, OX1 3PT, UK
- Department of Physics, Clarendon Laboratory, Parks Road, OX1 3PUT, Oxford, UK
| | - Laura L. Gathercole
- Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, OX3 0BP, UK
| | - Thomas Cornfield
- Oxford Centre for Diabetes, Endocrinology and Metabolism, NIHR Oxford Biomedical Research Centre, University of Oxford, Churchill Hospital, Oxford, OX3 7LE, UK
| | - Nikolaos Nikolaou
- Oxford Centre for Diabetes, Endocrinology and Metabolism, NIHR Oxford Biomedical Research Centre, University of Oxford, Churchill Hospital, Oxford, OX3 7LE, UK
| | - Shelley E. Harris
- Oxford Centre for Diabetes, Endocrinology and Metabolism, NIHR Oxford Biomedical Research Centre, University of Oxford, Churchill Hospital, Oxford, OX3 7LE, UK
| | - Ahmad Moolla
- Oxford Centre for Diabetes, Endocrinology and Metabolism, NIHR Oxford Biomedical Research Centre, University of Oxford, Churchill Hospital, Oxford, OX3 7LE, UK
| | - Nantia Othonos
- Oxford Centre for Diabetes, Endocrinology and Metabolism, NIHR Oxford Biomedical Research Centre, University of Oxford, Churchill Hospital, Oxford, OX3 7LE, UK
| | - Lisa C. Heather
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, OX1 3PT, UK
| | - Thomas Marjot
- Oxford Centre for Diabetes, Endocrinology and Metabolism, NIHR Oxford Biomedical Research Centre, University of Oxford, Churchill Hospital, Oxford, OX3 7LE, UK
| | - Damian J. Tyler
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, OX1 3PT, UK
- Oxford Centre for Clinical Magnetic Resonance Research, Division of Cardiovascular Medicine, University of Oxford, Oxford, OX1 3PT, UK
| | - Carolyn Carr
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, OX1 3PT, UK
- Oxford Centre for Clinical Magnetic Resonance Research, Division of Cardiovascular Medicine, University of Oxford, Oxford, OX1 3PT, UK
| | - Leanne Hodson
- Oxford Centre for Diabetes, Endocrinology and Metabolism, NIHR Oxford Biomedical Research Centre, University of Oxford, Churchill Hospital, Oxford, OX3 7LE, UK
| | - Jane McKeating
- Nuffield Department of Medicine, University of Oxford, Oxford, OX3 7FZ, UK
| | - Jeremy W. Tomlinson
- Oxford Centre for Diabetes, Endocrinology and Metabolism, NIHR Oxford Biomedical Research Centre, University of Oxford, Churchill Hospital, Oxford, OX3 7LE, UK
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19
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Cacciottolo TM, Henning E, Keogh JM, Bel Lassen P, Lawler K, Bounds R, Ahmed R, Perdikari A, Mendes de Oliveira E, Smith M, Godfrey EM, Johnson E, Hodson L, Clément K, van der Klaauw AA, Farooqi IS. Obesity Due to Steroid Receptor Coactivator-1 Deficiency Is Associated With Endocrine and Metabolic Abnormalities. J Clin Endocrinol Metab 2022; 107:e2532-e2544. [PMID: 35137184 PMCID: PMC9113786 DOI: 10.1210/clinem/dgac067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Indexed: 11/19/2022]
Abstract
CONTEXT Genetic variants affecting the nuclear hormone receptor coactivator steroid receptor coactivator, SRC-1, have been identified in people with severe obesity and impair melanocortin signaling in cells and mice. As a result, obese patients with SRC-1 deficiency are being treated with a melanocortin 4 receptor agonist in clinical trials. OBJECTIVE Here, our aim was to comprehensively describe and characterize the clinical phenotype of SRC-1 variant carriers to facilitate diagnosis and clinical management. METHODS In genetic studies of 2462 people with severe obesity, we identified 23 rare heterozygous variants in SRC-1. We studied 29 adults and 18 children who were SRC-1 variant carriers and performed measurements of metabolic and endocrine function, liver imaging, and adipose tissue biopsies. Findings in adult SRC-1 variant carriers were compared to 30 age- and body mass index (BMI)-matched controls. RESULTS The clinical spectrum of SRC-1 variant carriers included increased food intake in children, normal basal metabolic rate, multiple fractures with minimal trauma (40%), persistent diarrhea, partial thyroid hormone resistance, and menorrhagia. Compared to age-, sex-, and BMI-matched controls, adult SRC-1 variant carriers had more severe adipose tissue fibrosis (46.2% vs 7.1% respectively, P = .03) and a suggestion of increased liver fibrosis (5/13 cases vs 2/13 in controls, odds ratio = 3.4), although this was not statistically significant. CONCLUSION SRC-1 variant carriers exhibit hyperphagia in childhood, severe obesity, and clinical features of partial hormone resistance. The presence of adipose tissue fibrosis and hepatic fibrosis in young patients suggests that close monitoring for the early development of obesity-associated metabolic complications is warranted.
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Affiliation(s)
- Tessa M Cacciottolo
- University of Cambridge Metabolic Research Laboratories and NIHR Cambridge Biomedical Research Centre, Wellcome-MRC Institute of Metabolic Science, Box 289, Addenbrooke’s Hospital, Cambridge CB2 0QQ, UK
| | - Elana Henning
- University of Cambridge Metabolic Research Laboratories and NIHR Cambridge Biomedical Research Centre, Wellcome-MRC Institute of Metabolic Science, Box 289, Addenbrooke’s Hospital, Cambridge CB2 0QQ, UK
| | - Julia M Keogh
- University of Cambridge Metabolic Research Laboratories and NIHR Cambridge Biomedical Research Centre, Wellcome-MRC Institute of Metabolic Science, Box 289, Addenbrooke’s Hospital, Cambridge CB2 0QQ, UK
| | - Pierre Bel Lassen
- Sorbonne Université, INSERM, Nutrition and Obesities: Systemic Approaches (NutriOmics) Research Group and Assistance Publique hôpitaux de Paris, Nutrition Department, Pitié-Salpêtrière Hospital, 75013 Paris, France
| | - Katherine Lawler
- University of Cambridge Metabolic Research Laboratories and NIHR Cambridge Biomedical Research Centre, Wellcome-MRC Institute of Metabolic Science, Box 289, Addenbrooke’s Hospital, Cambridge CB2 0QQ, UK
| | - Rebecca Bounds
- University of Cambridge Metabolic Research Laboratories and NIHR Cambridge Biomedical Research Centre, Wellcome-MRC Institute of Metabolic Science, Box 289, Addenbrooke’s Hospital, Cambridge CB2 0QQ, UK
| | - Rachel Ahmed
- University of Cambridge Metabolic Research Laboratories and NIHR Cambridge Biomedical Research Centre, Wellcome-MRC Institute of Metabolic Science, Box 289, Addenbrooke’s Hospital, Cambridge CB2 0QQ, UK
| | - Aliki Perdikari
- University of Cambridge Metabolic Research Laboratories and NIHR Cambridge Biomedical Research Centre, Wellcome-MRC Institute of Metabolic Science, Box 289, Addenbrooke’s Hospital, Cambridge CB2 0QQ, UK
| | - Edson Mendes de Oliveira
- University of Cambridge Metabolic Research Laboratories and NIHR Cambridge Biomedical Research Centre, Wellcome-MRC Institute of Metabolic Science, Box 289, Addenbrooke’s Hospital, Cambridge CB2 0QQ, UK
| | - Miriam Smith
- University of Cambridge Metabolic Research Laboratories and NIHR Cambridge Biomedical Research Centre, Wellcome-MRC Institute of Metabolic Science, Box 289, Addenbrooke’s Hospital, Cambridge CB2 0QQ, UK
| | - Edmund M Godfrey
- Department of Radiology, Addenbrooke’s Hospital, Cambridge CB2 0QQ, UK
| | - Elspeth Johnson
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital and National Institute for Health Research Oxford Biomedical Research Centre, Oxford University Hospitals Foundation Trust, Headington, Oxford OX3 7LE, UK
| | - Leanne Hodson
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital and National Institute for Health Research Oxford Biomedical Research Centre, Oxford University Hospitals Foundation Trust, Headington, Oxford OX3 7LE, UK
| | - Karine Clément
- Sorbonne Université, INSERM, Nutrition and Obesities: Systemic Approaches (NutriOmics) Research Group and Assistance Publique hôpitaux de Paris, Nutrition Department, Pitié-Salpêtrière Hospital, 75013 Paris, France
| | - Agatha A van der Klaauw
- University of Cambridge Metabolic Research Laboratories and NIHR Cambridge Biomedical Research Centre, Wellcome-MRC Institute of Metabolic Science, Box 289, Addenbrooke’s Hospital, Cambridge CB2 0QQ, UK
| | - I Sadaf Farooqi
- University of Cambridge Metabolic Research Laboratories and NIHR Cambridge Biomedical Research Centre, Wellcome-MRC Institute of Metabolic Science, Box 289, Addenbrooke’s Hospital, Cambridge CB2 0QQ, UK
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20
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Dearlove DJ, Soto Mota A, Hauton D, Pinnick K, Evans R, Miller J, Fischer R, Mccullagh JS, Hodson L, Clarke K, Cox PJ. The effects of endogenously- and exogenously-induced hyperketonemia on exercise performance and adaptation. Physiol Rep 2022; 10:e15309. [PMID: 35614576 PMCID: PMC9133544 DOI: 10.14814/phy2.15309] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 05/02/2022] [Accepted: 05/05/2022] [Indexed: 05/22/2023] Open
Abstract
Elevating blood ketones may enhance exercise capacity and modulate adaptations to exercise training; however, these effects may depend on whether hyperketonemia is induced endogenously through dietary carbohydrate restriction, or exogenously through ketone supplementation. To determine this, we compared the effects of endogenously- and exogenously-induced hyperketonemia on exercise capacity and adaptation. Trained endurance athletes undertook 6 days of laboratory based cycling ("race") whilst following either: a carbohydrate-rich control diet (n = 7; CHO); a carbohydrate-rich diet + ketone drink four-times daily (n = 7; Ex Ket); or a ketogenic diet (n = 7; End Ket). Exercise capacity was measured daily, and adaptations in exercise metabolism, exercise physiology and postprandial insulin sensitivity (via an oral glucose tolerance test) were measured before and after dietary interventions. Urinary β-hydroxybutyrate increased by ⁓150-fold and ⁓650-fold versus CHO with Ex Ket and End Ket, respectively. Exercise capacity was increased versus pre-intervention by ~5% on race day 1 with CHO (p < 0.05), by 6%-8% on days 1, 4, and 6 (all p < 0.05) with Ex Ket and decreased by 48%-57% on all race days (all p > 0.05) with End Ket. There was an ⁓3-fold increase in fat oxidation from pre- to post-intervention (p < 0.05) with End Ket and increased perceived exercise exertion (p < 0.05). No changes in exercise substrate metabolism occurred with Ex Ket, but participants had blunted postprandial insulin sensitivity (p < 0.05). Dietary carbohydrate restriction and ketone supplementation both induce hyperketonemia; however, these are distinct physiological conditions with contrasting effects on exercise capacity and adaptation to exercise training.
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Affiliation(s)
- David J. Dearlove
- Department of Physiology, Anatomy and GeneticsUniversity of OxfordHeadingtonOxfordUnited Kingdom
| | - Adrian Soto Mota
- Department of Physiology, Anatomy and GeneticsUniversity of OxfordHeadingtonOxfordUnited Kingdom
| | - David Hauton
- Chemistry Research LaboratoryUniversity of OxfordHeadingtonOxfordUnited Kingdom
| | - Katherine Pinnick
- Oxford Centre for Diabetes, Endocrinology and MetabolismChurchill Hospital and Oxford NIHRBiomedical Research CentreUniversity of OxfordHeadingtonOxfordUnited Kingdom
| | - Rhys Evans
- Department of Physiology, Anatomy and GeneticsUniversity of OxfordHeadingtonOxfordUnited Kingdom
| | - Jack Miller
- Department of Physiology, Anatomy and GeneticsUniversity of OxfordHeadingtonOxfordUnited Kingdom
- The PET Research Centre and The MR Research CentreAarhus UniversityHeadingtonOxfordUnited Kingdom
- Clarendon LaboratoryDepartment of PhysicsUniversity of OxfordHeadingtonOxfordUnited Kingdom
| | - Roman Fischer
- Target Discovery InstituteUniversity of OxfordHeadingtonOxfordUnited Kingdom
| | | | - Leanne Hodson
- Oxford Centre for Diabetes, Endocrinology and MetabolismChurchill Hospital and Oxford NIHRBiomedical Research CentreUniversity of OxfordHeadingtonOxfordUnited Kingdom
| | - Kieran Clarke
- Department of Physiology, Anatomy and GeneticsUniversity of OxfordHeadingtonOxfordUnited Kingdom
| | - Pete J. Cox
- Department of Physiology, Anatomy and GeneticsUniversity of OxfordHeadingtonOxfordUnited Kingdom
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21
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Luukkonen PK, Qadri S, Ahlholm N, Porthan K, Männistö V, Sammalkorpi H, Penttilä AK, Hakkarainen A, Lehtimäki TE, Gaggini M, Gastaldelli A, Ala-Korpela M, Orho-Melander M, Arola J, Juuti A, Pihlajamäki J, Hodson L, Yki-Järvinen H. Distinct contributions of metabolic dysfunction and genetic risk factors in the pathogenesis of non-alcoholic fatty liver disease. J Hepatol 2022; 76:526-535. [PMID: 34710482 PMCID: PMC8852745 DOI: 10.1016/j.jhep.2021.10.013] [Citation(s) in RCA: 71] [Impact Index Per Article: 35.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 10/09/2021] [Accepted: 10/14/2021] [Indexed: 12/14/2022]
Abstract
BACKGROUND & AIMS There is substantial inter-individual variability in the risk of non-alcoholic fatty liver disease (NAFLD). Part of which is explained by insulin resistance (IR) ('MetComp') and part by common modifiers of genetic risk ('GenComp'). We examined how IR on the one hand and genetic risk on the other contribute to the pathogenesis of NAFLD. METHODS We studied 846 individuals: 492 were obese patients with liver histology and 354 were individuals who underwent intrahepatic triglyceride measurement by proton magnetic resonance spectroscopy. A genetic risk score was calculated using the number of risk alleles in PNPLA3, TM6SF2, MBOAT7, HSD17B13 and MARC1. Substrate concentrations were assessed by serum NMR metabolomics. In subsets of participants, non-esterified fatty acids (NEFAs) and their flux were assessed by D5-glycerol and hyperinsulinemic-euglycemic clamp (n = 41), and hepatic de novo lipogenesis (DNL) was measured by D2O (n = 61). RESULTS We found that substrate surplus (increased concentrations of 28 serum metabolites including glucose, glycolytic intermediates, and amino acids; increased NEFAs and their flux; increased DNL) characterized the 'MetComp'. In contrast, the 'GenComp' was not accompanied by any substrate excess but was characterized by an increased hepatic mitochondrial redox state, as determined by serum β-hydroxybutyrate/acetoacetate ratio, and inhibition of hepatic pathways dependent on tricarboxylic acid cycle activity, such as DNL. Serum β-hydroxybutyrate/acetoacetate ratio correlated strongly with all histological features of NAFLD. IR and hepatic mitochondrial redox state conferred additive increases in histological features of NAFLD. CONCLUSIONS These data show that the mechanisms underlying 'Metabolic' and 'Genetic' components of NAFLD are fundamentally different. These findings may have implications with respect to the diagnosis and treatment of NAFLD. LAY SUMMARY The pathogenesis of non-alcoholic fatty liver disease can be explained in part by a metabolic component, including obesity, and in part by a genetic component. Herein, we demonstrate that the mechanisms underlying these components are fundamentally different: the metabolic component is characterized by hepatic oversupply of substrates, such as sugars, lipids and amino acids. In contrast, the genetic component is characterized by impaired hepatic mitochondrial function, making the liver less able to metabolize these substrates.
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Affiliation(s)
- Panu K Luukkonen
- Department of Internal Medicine, Yale University, New Haven, CT, USA; Department of Medicine, University of Helsinki and Helsinki University Hospital, Finland; Minerva Foundation Institute for Medical Research, Helsinki, Finland.
| | - Sami Qadri
- Department of Medicine, University of Helsinki and Helsinki University Hospital, Finland; Minerva Foundation Institute for Medical Research, Helsinki, Finland
| | - Noora Ahlholm
- Department of Medicine, University of Helsinki and Helsinki University Hospital, Finland; Minerva Foundation Institute for Medical Research, Helsinki, Finland
| | - Kimmo Porthan
- Department of Medicine, University of Helsinki and Helsinki University Hospital, Finland; Minerva Foundation Institute for Medical Research, Helsinki, Finland
| | - Ville Männistö
- Department of Medicine, University of Eastern Finland and Kuopio University Hospital, Kuopio, Finland
| | - Henna Sammalkorpi
- Department of Abdominal Surgery, Abdominal Center, University of Helsinki and Helsinki University Hospital, Finland
| | - Anne K Penttilä
- Department of Abdominal Surgery, Abdominal Center, University of Helsinki and Helsinki University Hospital, Finland
| | - Antti Hakkarainen
- Department of Radiology, HUS Medical Imaging Center, University of Helsinki and Helsinki University Hospital, Finland; Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Espoo, Finland
| | - Tiina E Lehtimäki
- Department of Radiology, HUS Medical Imaging Center, University of Helsinki and Helsinki University Hospital, Finland
| | | | | | - Mika Ala-Korpela
- Computational Medicine, Faculty of Medicine, University of Oulu and Biocenter Oulu, Finland; Center for Life Course Health Research, Faculty of Medicine, University of Oulu, Oulu, Finland; University of Eastern Finland, Kuopio, Finland; NMR Metabolomics Laboratory, School of Pharmacy, University of Eastern Finland and Kuopio University Hospital, Kuopio, Finland
| | - Marju Orho-Melander
- Department of Clinical Sciences, Diabetes and Endocrinology, University Hospital Malmö, Lund University, Malmö, Sweden
| | - Johanna Arola
- Department of Pathology, University of Helsinki and Helsinki University Hospital, Finland
| | - Anne Juuti
- Department of Abdominal Surgery, Abdominal Center, University of Helsinki and Helsinki University Hospital, Finland
| | - Jussi Pihlajamäki
- Institute of Public Health and Clinical Nutrition, University of Eastern Finland and Kuopio University Hospital, Kuopio, Finland; Department of Medicine, Endocrinology and Clinical Nutrition, University of Eastern Finland and Kuopio University Hospital, Kuopio, Finland
| | - Leanne Hodson
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford & NIHR Oxford Biomedical Research Centre, Oxford University Hospitals Foundation Trust, UK
| | - Hannele Yki-Järvinen
- Department of Medicine, University of Helsinki and Helsinki University Hospital, Finland; Minerva Foundation Institute for Medical Research, Helsinki, Finland.
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22
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Abstract
The liver is a key metabolic organ that undertakes a multitude of physiological processes over the course of a day, including intrahepatic lipid and glucose metabolism which plays a key role in the regulation of systemic lipid and glucose concentrations. It serves as an intermediary organ between exogenous (dietary) and endogenous energy supply to extrahepatic organs. Thus, perturbations in hepatic metabolism can impact widely on metabolic disease risk. For example, the accumulation of intra-hepatocellular TAG (IHTG), for which adiposity is almost invariably a causative factor may result in dysregulation of metabolic pathways. Accumulation of IHTG is likely due to an imbalance between fatty acid delivery, synthesis and removal (via oxidation or export as TAG) from the liver; insulin plays a key role in all of these processes.
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Affiliation(s)
- S R Nagarajan
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Oxford, UK
| | - E Cross
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Oxford, UK
| | - F Sanna
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Oxford, UK
| | - L Hodson
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Oxford, UK
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23
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Green CJ, Marjot T, Walsby-Tickle J, Charlton C, Cornfield T, Westcott F, Pinnick KE, Moolla A, Hazlehurst JM, McCullagh J, Tomlinson JW, Hodson L. Metformin maintains intrahepatic triglyceride content through increased hepatic de novo lipogenesis. Eur J Endocrinol 2022; 186:367-377. [PMID: 35038311 PMCID: PMC8859923 DOI: 10.1530/eje-21-0850] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Accepted: 01/17/2022] [Indexed: 12/05/2022]
Abstract
OBJECTIVE Metformin is a first-line pharmacotherapy in the treatment of type 2 diabetes, a condition closely associated with non-alcoholic fatty liver disease (NAFLD). Although metformin promotes weight loss and improves insulin sensitivity, its effect on intrahepatic triglyceride (IHTG) remains unclear. We investigated the effect of metformin on IHTG, hepatic de novo lipogenesis (DNL), and fatty acid (FA) oxidation in vivo in humans. DESIGN AND METHODS Metabolic investigations, using stable-isotope tracers, were performed in ten insulin-resistant, overweight/obese human participants with NAFLD who were treatment naïve before and after 12 weeks of metformin treatment. The effect of metformin on markers of s.c. adipose tissue FA metabolism and function, along with the plasma metabolome, was investigated. RESULTS Twelve weeks of treatment with metformin resulted in a significant reduction in body weight and improved insulin sensitivity, but IHTG content and FA oxidation remained unchanged. Metformin treatment was associated with a significant decrease in VLDL-triglyceride (TG) concentrations and a significant increase in the relative contribution of DNL-derived FAs to VLDL-TG. There were subtle and relatively few changes in s.c. adipose tissue FA metabolism and the plasma metabolome with metformin treatment. CONCLUSIONS We demonstrate the mechanisms of action of metformin whereby it improves insulin sensitivity and promotes weight loss, without improvement in IHTG; these observations are partly explained through increased hepatic DNL and a lack of change in FA oxidation.
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Affiliation(s)
- Charlotte J Green
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford, UK
| | - Thomas Marjot
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford, UK
- Translational Gastroenterology Unit, NIHR Oxford Biomedical Research Centre, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | | | - Catriona Charlton
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford, UK
| | - Thomas Cornfield
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford, UK
| | - Felix Westcott
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford, UK
| | - Katherine E Pinnick
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford, UK
| | - Ahmad Moolla
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford, UK
| | - Jonathan M Hazlehurst
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford, UK
- Institute of Metabolism and Systems Research, University of Birmingham, Edgbaston, Birmingham, UK
| | - James McCullagh
- Chemistry Research Laboratory, University of Oxford, Oxford, UK
| | - Jeremy W Tomlinson
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford, UK
- NIHR Oxford Biomedical Research Centre, Oxford University Hospital Trusts, Oxford, UK
| | - Leanne Hodson
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford, UK
- NIHR Oxford Biomedical Research Centre, Oxford University Hospital Trusts, Oxford, UK
- Correspondence should be addressed to L Hodson;
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24
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Yki-Järvinen H, Luukkonen PK, Hodson L, Moore JB. Dietary carbohydrates and fats in nonalcoholic fatty liver disease. Nat Rev Gastroenterol Hepatol 2021; 18:770-786. [PMID: 34257427 DOI: 10.1038/s41575-021-00472-y] [Citation(s) in RCA: 89] [Impact Index Per Article: 29.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/14/2021] [Indexed: 02/06/2023]
Abstract
The global prevalence of nonalcoholic fatty liver disease (NAFLD) has dramatically increased in parallel with the epidemic of obesity. Controversy has emerged around dietary guidelines recommending low-fat-high-carbohydrate diets and the roles of dietary macronutrients in the pathogenesis of metabolic disease. In this Review, the topical questions of whether and how dietary fats and carbohydrates, including free sugars, differentially influence the accumulation of liver fat (specifically, intrahepatic triglyceride (IHTG) content) are addressed. Focusing on evidence from humans, we examine data from stable isotope studies elucidating how macronutrients regulate IHTG synthesis and disposal, alter pools of bioactive lipids and influence insulin sensitivity. In addition, we review cross-sectional studies on dietary habits of patients with NAFLD and randomized controlled trials on the effects of altering dietary macronutrients on IHTG. Perhaps surprisingly, evidence to date shows no differential effects between free sugars, with both glucose and fructose increasing IHTG in the context of excess energy. Moreover, saturated fat raises IHTG more than polyunsaturated or monounsaturated fats, with adverse effects on insulin sensitivity, which are probably mediated in part by increased ceramide synthesis. Taken together, the data support the use of diets that have a reduced content of free sugars, refined carbohydrates and saturated fat in the treatment of NAFLD.
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Affiliation(s)
- Hannele Yki-Järvinen
- Department of Medicine, Helsinki University Hospital and University of Helsinki, Helsinki, Finland. .,Minerva Foundation Institute for Medical Research, Helsinki, Finland.
| | - Panu K Luukkonen
- Department of Medicine, Helsinki University Hospital and University of Helsinki, Helsinki, Finland.,Minerva Foundation Institute for Medical Research, Helsinki, Finland.,Department of Internal Medicine, Yale University, New Haven, CT, USA
| | - Leanne Hodson
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, UK.,National Institute for Health Research Oxford Biomedical Research Centre, Oxford University Hospitals Foundation Trust, Oxford, UK
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25
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Ruuth M, Lahelma M, Luukkonen PK, Lorey MB, Qadri S, Sädevirta S, Hyötyläinen T, Kovanen PT, Hodson L, Yki-Järvinen H, Öörni K. Overfeeding Saturated Fat Increases LDL (Low-Density Lipoprotein) Aggregation Susceptibility While Overfeeding Unsaturated Fat Decreases Proteoglycan-Binding of Lipoproteins. Arterioscler Thromb Vasc Biol 2021; 41:2823-2836. [PMID: 34470478 PMCID: PMC8545249 DOI: 10.1161/atvbaha.120.315766] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Supplemental Digital Content is available in the text. Objective: We recently showed that measurement of the susceptibility of LDL (low-density lipoprotein) to aggregation is an independent predictor of cardiovascular events. We now wished to compare effects of overfeeding different dietary macronutrients on LDL aggregation, proteoglycan-binding of plasma lipoproteins, and on the concentration of oxidized LDL in plasma, 3 in vitro parameters consistent with increased atherogenicity. Approach and Results: The participants (36 subjects; age, 48±10 years; body mass index, 30.9±6.2 kg/m2) were randomized to consume an extra 1000 kcal/day of either unsaturated fat, saturated fat, or simple sugars (CARB) for 3 weeks. We measured plasma proatherogenic properties (susceptibility of LDL to aggregation, proteoglycan-binding, oxidized LDL) and concentrations and composition of plasma lipoproteins using nuclear magnetic resonance spectroscopy, and in LDL using liquid chromatography mass spectrometry, before and after the overfeeding diets. LDL aggregation increased in the saturated fat but not the other groups. This change was associated with increased sphingolipid and saturated triacylglycerols in LDL and in plasma and reduction of clusterin on LDL particles. Proteoglycan binding of plasma lipoproteins decreased in the unsaturated fat group relative to the baseline diet. Lipoprotein properties remained unchanged in the CARB group. Conclusions: The type of fat during 3 weeks of overfeeding is an important determinant of the characteristics and functional properties of plasma lipoproteins in humans. Registration: URL: http://www.clinicaltrials.gov; Unique identifier NCT02133144.
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Affiliation(s)
- Maija Ruuth
- Atherosclerosis Research Laboratory, Wihuri Research Institute, Haartmaninkatu, Helsinki, Finland (M.R., M.B.L., P.T.K., K.Ö.).,Research Programs Unit, Faculty of Medicine, University of Helsinki, Finland (M.R.)
| | - Mari Lahelma
- Minerva Foundation Institute for Medical Research, Helsinki, Finland (M.L., P.K.L., S.Q., S.S., H.Y.-J.).,Department of Medicine, University of Helsinki and Helsinki University Hospital, Finland (M.L., P.K.L., S.Q., S.S., H.Y.-J.)
| | - Panu K Luukkonen
- Minerva Foundation Institute for Medical Research, Helsinki, Finland (M.L., P.K.L., S.Q., S.S., H.Y.-J.).,Department of Medicine, University of Helsinki and Helsinki University Hospital, Finland (M.L., P.K.L., S.Q., S.S., H.Y.-J.)
| | - Martina B Lorey
- Atherosclerosis Research Laboratory, Wihuri Research Institute, Haartmaninkatu, Helsinki, Finland (M.R., M.B.L., P.T.K., K.Ö.)
| | - Sami Qadri
- Minerva Foundation Institute for Medical Research, Helsinki, Finland (M.L., P.K.L., S.Q., S.S., H.Y.-J.).,Department of Medicine, University of Helsinki and Helsinki University Hospital, Finland (M.L., P.K.L., S.Q., S.S., H.Y.-J.)
| | - Sanja Sädevirta
- Minerva Foundation Institute for Medical Research, Helsinki, Finland (M.L., P.K.L., S.Q., S.S., H.Y.-J.).,Department of Medicine, University of Helsinki and Helsinki University Hospital, Finland (M.L., P.K.L., S.Q., S.S., H.Y.-J.)
| | - Tuulia Hyötyläinen
- School of Science and Technology, Örebro University, Örebro, Sweden (T.H.)
| | - Petri T Kovanen
- Atherosclerosis Research Laboratory, Wihuri Research Institute, Haartmaninkatu, Helsinki, Finland (M.R., M.B.L., P.T.K., K.Ö.)
| | - Leanne Hodson
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, and National Institute for Health Research Oxford Biomedical Research Centre, Oxford University Hospital Trusts, United Kingdom (L.H.)
| | - Hannele Yki-Järvinen
- Minerva Foundation Institute for Medical Research, Helsinki, Finland (M.L., P.K.L., S.Q., S.S., H.Y.-J.).,Department of Medicine, University of Helsinki and Helsinki University Hospital, Finland (M.L., P.K.L., S.Q., S.S., H.Y.-J.)
| | - Katariina Öörni
- Atherosclerosis Research Laboratory, Wihuri Research Institute, Haartmaninkatu, Helsinki, Finland (M.R., M.B.L., P.T.K., K.Ö.)
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26
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Nasteska D, Cuozzo F, Viloria K, Johnson EM, Thakker A, Bany Bakar R, Westbrook RL, Barlow JP, Hoang M, Joseph JW, Lavery GG, Akerman I, Cantley J, Hodson L, Tennant DA, Hodson DJ. Prolyl-4-hydroxylase 3 maintains β cell glucose metabolism during fatty acid excess in mice. JCI Insight 2021; 6:e140288. [PMID: 34264866 PMCID: PMC8409982 DOI: 10.1172/jci.insight.140288] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Accepted: 07/14/2021] [Indexed: 02/06/2023] Open
Abstract
The α-ketoglutarate–dependent dioxygenase, prolyl-4-hydroxylase 3 (PHD3), is an HIF target that uses molecular oxygen to hydroxylate peptidyl prolyl residues. Although PHD3 has been reported to influence cancer cell metabolism and liver insulin sensitivity, relatively little is known about the effects of this highly conserved enzyme in insulin-secreting β cells in vivo. Here, we show that the deletion of PHD3 specifically in β cells (βPHD3KO) was associated with impaired glucose homeostasis in mice fed a high-fat diet. In the early stages of dietary fat excess, βPHD3KO islets energetically rewired, leading to defects in the management of pyruvate fate and a shift from glycolysis to increased fatty acid oxidation (FAO). However, under more prolonged metabolic stress, this switch to preferential FAO in βPHD3KO islets was associated with impaired glucose-stimulated ATP/ADP rises, Ca2+ fluxes, and insulin secretion. Thus, PHD3 might be a pivotal component of the β cell glucose metabolism machinery in mice by suppressing the use of fatty acids as a primary fuel source during the early phases of metabolic stress.
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Affiliation(s)
- Daniela Nasteska
- Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, United Kingdom.,Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, United Kingdom.,Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham, Birmingham, United Kingdom
| | - Federica Cuozzo
- Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, United Kingdom.,Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, United Kingdom.,Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham, Birmingham, United Kingdom
| | - Katrina Viloria
- Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, United Kingdom.,Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, United Kingdom.,Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham, Birmingham, United Kingdom
| | - Elspeth M Johnson
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Oxford, United Kingdom.,NIHR Oxford Biomedical Research Centre, Churchill Hospital, Oxford, United Kingdom
| | - Alpesh Thakker
- Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, United Kingdom.,Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, United Kingdom
| | - Rula Bany Bakar
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Rebecca L Westbrook
- Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, United Kingdom.,Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, United Kingdom
| | - Jonathan P Barlow
- Mitochondrial Profiling Centre, School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Monica Hoang
- School of Pharmacy, University of Waterloo, Kitchener, Ontario, Canada
| | - Jamie W Joseph
- School of Pharmacy, University of Waterloo, Kitchener, Ontario, Canada
| | - Gareth G Lavery
- Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, United Kingdom.,Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, United Kingdom
| | - Ildem Akerman
- Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, United Kingdom.,Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, United Kingdom
| | - James Cantley
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom.,Division of Systems Medicine, School of Medicine, University of Dundee, Dundee, United Kingdom
| | - Leanne Hodson
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Oxford, United Kingdom.,NIHR Oxford Biomedical Research Centre, Churchill Hospital, Oxford, United Kingdom
| | - Daniel A Tennant
- Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, United Kingdom.,Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, United Kingdom
| | - David J Hodson
- Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, United Kingdom.,Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, United Kingdom.,Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham, Birmingham, United Kingdom
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27
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Hunter AL, Pelekanou CE, Barron NJ, Northeast RC, Grudzien M, Adamson AD, Downton P, Cornfield T, Cunningham PS, Billaud JN, Hodson L, Loudon ASI, Unwin RD, Iqbal M, Ray DW, Bechtold DA. Adipocyte NR1D1 dictates adipose tissue expansion during obesity. eLife 2021; 10:e63324. [PMID: 34350828 PMCID: PMC8360653 DOI: 10.7554/elife.63324] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Accepted: 07/30/2021] [Indexed: 12/13/2022] Open
Abstract
The circadian clock component NR1D1 (REVERBα) is considered a dominant regulator of lipid metabolism, with global Nr1d1 deletion driving dysregulation of white adipose tissue (WAT) lipogenesis and obesity. However, a similar phenotype is not observed under adipocyte-selective deletion (Nr1d1Flox2-6:AdipoqCre), and transcriptional profiling demonstrates that, under basal conditions, direct targets of NR1D1 regulation are limited, and include the circadian clock and collagen dynamics. Under high-fat diet (HFD) feeding, Nr1d1Flox2-6:AdipoqCre mice do manifest profound obesity, yet without the accompanying WAT inflammation and fibrosis exhibited by controls. Integration of the WAT NR1D1 cistrome with differential gene expression reveals broad control of metabolic processes by NR1D1 which is unmasked in the obese state. Adipocyte NR1D1 does not drive an anticipatory daily rhythm in WAT lipogenesis, but rather modulates WAT activity in response to alterations in metabolic state. Importantly, NR1D1 action in adipocytes is critical to the development of obesity-related WAT pathology and insulin resistance.
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Affiliation(s)
- Ann Louise Hunter
- Centre for Biological Timing, Faculty of Biology, Medicine and Health, University of ManchesterManchesterUnited Kingdom
| | - Charlotte E Pelekanou
- Centre for Biological Timing, Faculty of Biology, Medicine and Health, University of ManchesterManchesterUnited Kingdom
| | - Nichola J Barron
- Centre for Biological Timing, Faculty of Biology, Medicine and Health, University of ManchesterManchesterUnited Kingdom
| | - Rebecca C Northeast
- Centre for Biological Timing, Faculty of Biology, Medicine and Health, University of ManchesterManchesterUnited Kingdom
| | - Magdalena Grudzien
- Centre for Biological Timing, Faculty of Biology, Medicine and Health, University of ManchesterManchesterUnited Kingdom
| | - Antony D Adamson
- Centre for Biological Timing, Faculty of Biology, Medicine and Health, University of ManchesterManchesterUnited Kingdom
| | - Polly Downton
- Centre for Biological Timing, Faculty of Biology, Medicine and Health, University of ManchesterManchesterUnited Kingdom
| | - Thomas Cornfield
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, and NIHR Oxford Biomedical Research Centre, John Radcliffe HospitalOxfordUnited Kingdom
| | - Peter S Cunningham
- Centre for Biological Timing, Faculty of Biology, Medicine and Health, University of ManchesterManchesterUnited Kingdom
| | | | - Leanne Hodson
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, and NIHR Oxford Biomedical Research Centre, John Radcliffe HospitalOxfordUnited Kingdom
| | - Andrew SI Loudon
- Centre for Biological Timing, Faculty of Biology, Medicine and Health, University of ManchesterManchesterUnited Kingdom
| | - Richard D Unwin
- Stoller Biomarker Discovery Centre, Division of Cancer Sciences, Faculty of Biology, Medicine and Health, University of ManchesterManchesterUnited Kingdom
| | - Mudassar Iqbal
- Division of Informatics, Imaging and Data Sciences, Faculty of Biology, Medicine and Health, University of ManchesterManchesterUnited Kingdom
| | - David W Ray
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, and NIHR Oxford Biomedical Research Centre, John Radcliffe HospitalOxfordUnited Kingdom
| | - David A Bechtold
- Centre for Biological Timing, Faculty of Biology, Medicine and Health, University of ManchesterManchesterUnited Kingdom
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28
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Simons PIHG, Valkenburg O, Telgenkamp I, van der Waaij KM, de Groot DM, Veeraiah P, Bons JAP, Taskinen M, Borén J, Schrauwen P, Rutten JHW, Cassiman D, Schalkwijk CG, Stehouwer CDA, Schrauwen‐Hinderling VB, Hodson L, Brouwers MCGJ. Relationship between de novo lipogenesis and serum sex hormone binding globulin in humans. Clin Endocrinol (Oxf) 2021; 95:101-106. [PMID: 33715205 PMCID: PMC8287427 DOI: 10.1111/cen.14459] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 02/03/2021] [Accepted: 03/01/2021] [Indexed: 01/10/2023]
Abstract
OBJECTIVE Obesity and liver fat are associated with decreased levels of serum sex hormone binding globulin (SHBG). Laboratory studies suggest that hepatic de novo lipogenesis (DNL) is involved in the downregulation of SHBG synthesis. The aim of the present study was to address the role of DNL on serum SHBG in humans. DESIGN A cross-sectional study examining the association between DNL, measured by stable isotopes, and serum SHBG, stratified by sex. PARTICIPANTS Healthy men (n = 34) and women (n = 21) were combined from two cross-sectional studies. Forty-two per cent of participants had hepatic steatosis, and the majority were overweight (62%) or obese (27%). RESULTS DNL was inversely associated with SHBG in women (β: -0.015, 95% CI: -0.030; 0.000), but not in men (β: 0.007, 95% CI: -0.005; 0.019) (p for interaction = .068). Adjustment for study population, age and body mass index did not materially change these results, although statistical significance was lost after adjustment for serum insulin. CONCLUSIONS An inverse association between DNL and SHBG may explain the decreased SHBG levels that are observed in obesity, at least in women.
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Affiliation(s)
- Pomme I. H. G. Simons
- Division of Endocrinology and Metabolic DiseasesDepartment of Internal MedicineMaastricht University Medical CentreMaastrichtThe Netherlands
- Laboratory for Metabolism and Vascular MedicineMaastricht UniversityMaastrichtThe Netherlands
- CARIM School for Cardiovascular DiseasesMaastricht UniversityMaastrichtThe Netherlands
| | - Olivier Valkenburg
- Department of Reproductive MedicineMaastricht University Medical CentreMaastrichtThe Netherlands
| | - Ine Telgenkamp
- Division of Endocrinology and Metabolic DiseasesDepartment of Internal MedicineMaastricht University Medical CentreMaastrichtThe Netherlands
- Laboratory for Metabolism and Vascular MedicineMaastricht UniversityMaastrichtThe Netherlands
| | - Koen M. van der Waaij
- Division of Endocrinology and Metabolic DiseasesDepartment of Internal MedicineMaastricht University Medical CentreMaastrichtThe Netherlands
- Laboratory for Metabolism and Vascular MedicineMaastricht UniversityMaastrichtThe Netherlands
| | - David M. de Groot
- Division of Endocrinology and Metabolic DiseasesDepartment of Internal MedicineMaastricht University Medical CentreMaastrichtThe Netherlands
| | - Pandichelvam Veeraiah
- Department of Nutrition and Movement SciencesMaastricht UniversityMaastrichtNetherlands
- Department of Radiology and Nuclear MedicineMaastricht UniversityMaastrichtNetherlands
| | - Judith A. P. Bons
- Central Diagnostic LaboratoryMaastricht University Medical CentreMaastrichtNetherlands
| | - Marja‐Riitta Taskinen
- Research Program, Unit Clinical and Molecular MetabolismUniversity of HelsinkiHelsinkiFinland
| | - Jan Borén
- Department of Molecular and Clinical MedicineUniversity of GothenburgGothenburgSweden
| | - Patrick Schrauwen
- Department of Nutrition and Movement SciencesMaastricht UniversityMaastrichtNetherlands
| | - Joost H. W. Rutten
- Department of Internal MedicineRadboud University Medical CentreNijmegenThe Netherlands
| | - David Cassiman
- Department of Gastroenterology‐Hepatology and Metabolic CentreUniversity Hospital LeuvenLeuvenBelgium
| | - Casper G. Schalkwijk
- Laboratory for Metabolism and Vascular MedicineMaastricht UniversityMaastrichtThe Netherlands
- CARIM School for Cardiovascular DiseasesMaastricht UniversityMaastrichtThe Netherlands
| | - Coen D. A. Stehouwer
- Laboratory for Metabolism and Vascular MedicineMaastricht UniversityMaastrichtThe Netherlands
- CARIM School for Cardiovascular DiseasesMaastricht UniversityMaastrichtThe Netherlands
- Division of General Internal MedicineDepartment of Internal MedicineMaastricht University Medical CentreMaastrichtThe Netherlands
| | - Vera B. Schrauwen‐Hinderling
- Department of Nutrition and Movement SciencesMaastricht UniversityMaastrichtNetherlands
- Department of Radiology and Nuclear MedicineMaastricht UniversityMaastrichtNetherlands
| | - Leanne Hodson
- Oxford Centre for Diabetes, Endocrinology and MetabolismUniversity of OxfordOxfordUnited Kingdom
- National Institute for Health Research Oxford Biomedical Research CentreOxford University Hospitals Foundation TrustOxfordUnited Kingdom
| | - Martijn C. G. J. Brouwers
- Division of Endocrinology and Metabolic DiseasesDepartment of Internal MedicineMaastricht University Medical CentreMaastrichtThe Netherlands
- CARIM School for Cardiovascular DiseasesMaastricht UniversityMaastrichtThe Netherlands
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29
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Rosqvist F, Hodson L, Fielding BA. Editorial: Foods and Macronutrients in NAFLD: Associations, Effects and Mechanisms. Front Nutr 2021; 8:665436. [PMID: 33834036 PMCID: PMC8021691 DOI: 10.3389/fnut.2021.665436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 03/01/2021] [Indexed: 11/24/2022] Open
Affiliation(s)
- Fredrik Rosqvist
- Department of Public Health and Caring Sciences, Clinical Nutrition and Metabolism, Uppsala University, Uppsala, Sweden
| | - Leanne Hodson
- Oxford Center for Diabetes, Endocrinology and Metabolism, Churchill Hospital, University of Oxford, Oxford, United Kingdom.,Oxford NIHR Biomedical Research Center, Churchill Hospital, Oxford, United Kingdom
| | - Barbara A Fielding
- Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
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30
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Turner MC, Rimington RP, Martin NRW, Fleming JW, Capel AJ, Hodson L, Lewis MP. Physiological and pathophysiological concentrations of fatty acids induce lipid droplet accumulation and impair functional performance of tissue engineered skeletal muscle. J Cell Physiol 2021; 236:7033-7044. [PMID: 33738797 DOI: 10.1002/jcp.30365] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 02/11/2021] [Accepted: 03/08/2021] [Indexed: 12/19/2022]
Abstract
Fatty acids (FA) exert physiological and pathophysiological effects leading to changes in skeletal muscle metabolism and function, however, in vitro models to investigate these changes are limited. These experiments sought to establish the effects of physiological and pathophysiological concentrations of exogenous FA upon the function of tissue engineered skeletal muscle (TESkM). Cultured initially for 14 days, C2C12 TESkM was exposed to FA-free bovine serum albumin alone or conjugated to a FA mixture (oleic, palmitic, linoleic, and α-linoleic acids [OPLA] [ratio 45:30:24:1%]) at different concentrations (200 or 800 µM) for an additional 4 days. Subsequently, TESkM morphology, functional capacity, gene expression and insulin signaling were analyzed. There was a dose response increase in the number and size of lipid droplets within the TESkM (p < .05). Exposure to exogenous FA increased the messenger RNA expression of genes involved in lipid storage (perilipin 2 [p < .05]) and metabolism (pyruvate dehydrogenase lipoamide kinase isozyme 4 [p < .01]) in a dose dependent manner. TESkM force production was reduced (tetanic and single twitch) (p < .05) and increases in transcription of type I slow twitch fiber isoform, myosin heavy chain 7, were observed when cultured with 200 µM OPLA compared to control (p < .01). Four days of OPLA exposure results in lipid accumulation in TESkM which in turn results in changes in muscle function and metabolism; thus, providing insight ito the functional and mechanistic changes of TESkM in response to exogenous FA.
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Affiliation(s)
- Mark C Turner
- School of Sport, Exercise and Health Sciences, National Centre for Sport and Exercise Medicine, Loughborough University, Loughborough, UK.,Leicester Biomedical Research Centre, University Hospitals of Leicester NHS Trust, Leicester, UK.,Centre for Sport, Exercise and Life Sciences, Research Institute for Health and Wellbeing, Coventry University, Coventry, UK
| | - Rowan P Rimington
- School of Sport, Exercise and Health Sciences, National Centre for Sport and Exercise Medicine, Loughborough University, Loughborough, UK
| | - Neil R W Martin
- School of Sport, Exercise and Health Sciences, National Centre for Sport and Exercise Medicine, Loughborough University, Loughborough, UK
| | - Jacob W Fleming
- School of Sport, Exercise and Health Sciences, National Centre for Sport and Exercise Medicine, Loughborough University, Loughborough, UK
| | - Andrew J Capel
- School of Sport, Exercise and Health Sciences, National Centre for Sport and Exercise Medicine, Loughborough University, Loughborough, UK
| | - Leanne Hodson
- Oxford Center for Diabetes, Endocrinology and Metabolism, Oxford Biomedical Research Centre, Radcliffe Department of Medicine, Churchill Hospital, University of Oxford, Oxford, UK
| | - Mark P Lewis
- School of Sport, Exercise and Health Sciences, National Centre for Sport and Exercise Medicine, Loughborough University, Loughborough, UK
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Nikolaou N, Hodson L, Tomlinson JW. The role of 5-reduction in physiology and metabolic disease: evidence from cellular, pre-clinical and human studies. J Steroid Biochem Mol Biol 2021; 207:105808. [PMID: 33418075 DOI: 10.1016/j.jsbmb.2021.105808] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 12/31/2020] [Accepted: 01/03/2021] [Indexed: 01/01/2023]
Abstract
The 5-reductases (5α-reductase types 1, 2 and 3 [5αR1-3], 5β-reductase [5βR]) are steroid hormone metabolising enzymes that hold fundamental roles in human physiology and pathology. They possess broad substrate specificity converting many steroid hormones to their 5α- and 5β-reduced metabolites, as well as catalysing crucial steps in bile acid synthesis. 5αRs are fundamentally important in urogenital development by converting testosterone to the more potent androgen 5α-dihydrotestosterone (5αDHT); inactivating mutations in 5αR2 lead to disorders of sexual development. Due to the ability of the 5αRs to generate 5αDHT, they are an established drug target, and 5αR inhibitors are widely used for the treatment of androgen-dependent benign or malignant prostatic diseases. There is an emerging body of evidence to suggest that the 5-reductases can impact upon aspects of health and disease (other than urogenital development); alterations in their expression and activity have been associated with metabolic disease, polycystic ovarian syndrome, inflammation and bone metabolism. This review will outline the evidence base for the extra-urogenital role of 5-reductases from in vitro cell systems, pre-clinical models and human studies, and highlight the potential adverse effects of 5αR inhibition in human health and disease.
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Affiliation(s)
- Nikolaos Nikolaou
- Oxford Centre for Diabetes, Endocrinology and Metabolism, NIHR Oxford Biomedical Research Centre, University of Oxford, Churchill Hospital, Oxford, OX3 7LE, UK
| | - Leanne Hodson
- Oxford Centre for Diabetes, Endocrinology and Metabolism, NIHR Oxford Biomedical Research Centre, University of Oxford, Churchill Hospital, Oxford, OX3 7LE, UK
| | - Jeremy W Tomlinson
- Oxford Centre for Diabetes, Endocrinology and Metabolism, NIHR Oxford Biomedical Research Centre, University of Oxford, Churchill Hospital, Oxford, OX3 7LE, UK.
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32
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Parry SA, Rosqvist F, Cornfield T, Barrett A, Hodson L. Oxidation of dietary linoleate occurs to a greater extent than dietary palmitate in vivo in humans. Clin Nutr 2021; 40:1108-1114. [DOI: 10.1016/j.clnu.2020.07.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 06/08/2020] [Accepted: 07/13/2020] [Indexed: 01/22/2023]
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Dearlove DJ, Holdsworth D, Kirk T, Hodson L, Charidemou E, Kvalheim E, Stubbs B, Beevers A, Griffin JL, Evans R, Robertson J, Clarke K, Cox PJ. β-Hydroxybutyrate Oxidation in Exercise Is Impaired by Low-Carbohydrate and High-Fat Availability. Front Med (Lausanne) 2021; 8:721673. [PMID: 34901052 PMCID: PMC8655871 DOI: 10.3389/fmed.2021.721673] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Accepted: 10/25/2021] [Indexed: 12/18/2022] Open
Abstract
Purpose: In this study, we determined ketone oxidation rates in athletes under metabolic conditions of high and low carbohydrate (CHO) and fat availability. Methods: Six healthy male athletes completed 1 h of bicycle ergometer exercise at 75% maximal power (WMax) on three occasions. Prior to exercise, participants consumed 573 mg·kg bw-1 of a ketone ester (KE) containing a 13C label. To manipulate CHO availability, athletes undertook glycogen depleting exercise followed by isocaloric high-CHO or very-low-CHO diets. To manipulate fat availability, participants were given a continuous infusion of lipid during two visits. Using stable isotope methodology, β-hydroxybutyrate (βHB) oxidation rates were therefore investigated under the following metabolic conditions: (i) high CHO + normal fat (KE+CHO); (ii) high CHO + high fat KE+CHO+FAT); and (iii) low CHO + high fat (KE+FAT). Results: Pre-exercise intramuscular glycogen (IMGLY) was approximately halved in the KE+FAT vs. KE+CHO and KE+CHO+FAT conditions (both p < 0.05). Blood free fatty acids (FFA) and intramuscular long-chain acylcarnitines were significantly greater in the KE+FAT vs. other conditions and in the KE+CHO+FAT vs. KE+CHO conditions before exercise. Following ingestion of the 13C labeled KE, blood βHB levels increased to ≈4.5 mM before exercise in all conditions. βHB oxidation was modestly greater in the KE+CHO vs. KE+FAT conditions (mean diff. = 0.09 g·min-1, p = 0.03; d = 0.3), tended to be greater in the KE+CHO+FAT vs. KE+FAT conditions (mean diff. = 0.07 g·min-1; p = 0.1; d = 0.3) and were the same in the KE+CHO vs. KE+CHO+FAT conditions (p < 0.05; d < 0.1). A moderate positive correlation between pre-exercise IMGLY and βHB oxidation rates during exercise was present (p = 0.04; r = 0.5). Post-exercise intramuscular βHB abundance was markedly elevated in the KE+FAT vs. KE+CHO and KE+CHO+FAT conditions (both, p < 0.001; d = 2.3). Conclusion: βHB oxidation rates during exercise are modestly impaired by low CHO availability, independent of circulating βHB levels.
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Affiliation(s)
- David J Dearlove
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - David Holdsworth
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Tom Kirk
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Leanne Hodson
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Oxford NIHR Biomedical Research Centre, University of Oxford, Oxford, United Kingdom
| | - Evelina Charidemou
- Department of Biochemistry and Cambridge Systems Biology Centre, University of Cambridge, MRC Human Nutrition Research, Cambridge, United Kingdom
| | - Eline Kvalheim
- Department of Chemistry, University of Oxford, Oxford, United Kingdom
| | - Brianna Stubbs
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Andrew Beevers
- Research and Development Department, Sterling Pharma Solutions Ltd., Cramlington, United Kingdom
| | - Julian L Griffin
- Department of Biochemistry and Cambridge Systems Biology Centre, University of Cambridge, MRC Human Nutrition Research, Cambridge, United Kingdom
| | - Rhys Evans
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Jeremy Robertson
- Department of Chemistry, University of Oxford, Oxford, United Kingdom
| | - Kieran Clarke
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Pete J Cox
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
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Parry SA, Rosqvist F, Peters S, Young RK, Cornfield T, Dyson P, Hodson L. The influence of nutritional state on the fatty acid composition of circulating lipid fractions: implications for their use as biomarkers of dietary fat intake. Ups J Med Sci 2021; 126:7649. [PMID: 34471486 PMCID: PMC8384057 DOI: 10.48101/ujms.v126.7649] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Revised: 04/16/2021] [Accepted: 05/11/2021] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND The fatty acid (FA) composition of blood can be used as an objective biomarker of dietary FA intake. It remains unclear how the nutritional state influences the FA composition of plasma lipid fractions, and thus their usefulness as biomarkers in a non-fasted state. OBJECTIVES To investigate the associations between palmitate, oleate and linoleate in plasma lipid fractions and self-reported dietary FA intake, and assess the influence of meal consumption on the relative abundance of these FA in plasma lipid fractions (i.e. triglyceride [TG], phospholipids [PLs] and cholesterol esters [CEs]). DESIGN Analysis was performed in plasma samples collected from 49 (34 males and 15 females) participants aged 26-57 years with a body mass index (BMI) between 21.6 and 34.2 kg/m2, all of whom had participated in multiple study visits, thus a pooled cohort of 98 data sets was available for analysis. A subset (n = 25) had undergone nutritional interventions and was therefore used to investigate the relationship between the FA composition of plasma lipid fractions and dietary fat intake. RESULTS Significant (P < 0.05) positive associations were observed between dietary polyunsaturated fat and linoleate abundance in plasma CE. When investigating the influence of meal consumption on postprandial FA composition, we found plasma TG palmitate significantly (P < 0.05) decreased across the postprandial period, whereas oleate and linoleate increased. A similar pattern was observed in plasma PL, whereas linoleate abundance decreased in the plasma CE. CONCLUSION Our data demonstrate that the FA composition of plasma CE may be the lipid fraction to utilise as an objective biomarker when investigating recent (i.e. previous weeks-months) dietary FA intakes. In addition, we show that the consumption of a high-fat meal influences the FA composition of plasma TG, PL and CE over the course of the postprandial period, and therefore, suggest that fasting blood samples should be utilised when using FA composition as a biomarker of dietary FA intake.
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Affiliation(s)
- Sion A. Parry
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford, United Kingdom
| | - Fredrik Rosqvist
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford, United Kingdom
- Department of Public Health and Caring Sciences, Clinical Nutrition and Metabolism, Uppsala University, Uppsala, Sweden
| | - Sarah Peters
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford, United Kingdom
| | - Rebecca K. Young
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford, United Kingdom
| | - Thomas Cornfield
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford, United Kingdom
| | - Pamela Dyson
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford, United Kingdom
- National Institute for Health Research Oxford, Biomedical Research Centre, Oxford University, Hospital Trusts, Oxford, United Kingdom
| | - Leanne Hodson
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford, United Kingdom
- National Institute for Health Research Oxford, Biomedical Research Centre, Oxford University, Hospital Trusts, Oxford, United Kingdom
- CONTACT Leanne Hodson,
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Abstract
PURPOSE OF REVIEW Prevalence of metabolic-associated fatty liver disease (MAFLD) is increasing, and as pharmacological treatment does not exist, lifestyle interventions (i.e. diet and exercise) represent the cornerstone management and treatment strategy. Although the available data clearly demonstrate that changes in lifestyle influence intrahepatic triglyceride (IHTG) content, the mechanisms through which this is achieved are seldom investigated. Here, we review recent evidence demonstrating the influence of lifestyle interventions on hepatic fatty acid metabolism and IHTG content. RECENT FINDINGS Diet and exercise influence IHTG content through various, and often interrelated factors. These include alterations in whole-body and tissue-specific insulin sensitivity, which may influence the flux of fatty acid and lipogenic substrates to the liver, and changes in intrahepatic fatty acid synthesis and partitioning. Notably, there are only a few studies that have investigated intrahepatic fatty acid metabolism in vivo in humans before and after an intervention. SUMMARY Lifestyle interventions represent an effective means of influencing hepatic fatty acid metabolism. IHTG content is decreased without weight-loss either through exercise or by changing the macronutrient composition of the diet, although what the optimal macronutrient composition is to achieve this has yet to be defined.
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Affiliation(s)
- Sion A Parry
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Oxford
| | - Mark C Turner
- Research Centre for Sport, Exercise and Life Sciences, Coventry University, Coventry
| | - Leanne Hodson
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Oxford
- Oxford NIHR Biomedical Research Centre, Churchill Hospital, Oxford, UK
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36
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Qadri S, Lallukka-Brück S, Luukkonen PK, Zhou Y, Gastaldelli A, Orho-Melander M, Sammalkorpi H, Juuti A, Penttilä AK, Perttilä J, Hakkarainen A, Lehtimäki TE, Orešič M, Hyötyläinen T, Hodson L, Olkkonen VM, Yki-Järvinen H. The PNPLA3-I148M variant increases polyunsaturated triglycerides in human adipose tissue. Liver Int 2020; 40:2128-2138. [PMID: 32386450 DOI: 10.1111/liv.14507] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 04/23/2020] [Accepted: 05/02/2020] [Indexed: 12/11/2022]
Abstract
BACKGROUND & AIMS The I148M variant in PNPLA3 is the major genetic risk factor for non-alcoholic fatty liver disease (NAFLD). The liver is enriched with polyunsaturated triglycerides (PUFA-TGs) in PNPLA3-I148M carriers. Gene expression data indicate that PNPLA3 is liver-specific in humans, but whether it functions in adipose tissue (AT) is unknown. We investigated whether PNPLA3-I148M modifies AT metabolism in human NAFLD. METHODS Profiling of the AT lipidome and fasting serum non-esterified fatty acid (NEFA) composition was conducted in 125 volunteers (PNPLA3148MM/MI , n = 63; PNPLA3148II , n = 62). AT fatty acid composition was determined in 50 volunteers homozygous for the variant (PNPLA3148MM , n = 25) or lacking the variant (PNPLA3148II , n = 25). Whole-body insulin sensitivity of lipolysis was determined using [2 H5 ]glycerol, and PNPLA3 mRNA and protein levels were measured in subcutaneous AT and liver biopsies in a subset of the volunteers. RESULTS PUFA-TGs were significantly increased in AT in carriers versus non-carriers of PNPLA3-I148M. The variant did not alter the rate of lipolysis or the composition of fasting serum NEFAs. PNPLA3 mRNA was 33-fold higher in the liver than in AT (P < .0001). In contrast, PNPLA3 protein levels per tissue protein were three-fold higher in AT than the liver (P < .0001) and nine-fold higher when related to whole-body AT and liver tissue masses (P < .0001). CONCLUSIONS Contrary to previous assumptions, PNPLA3 is highly abundant in AT. PNPLA3-I148M locally remodels AT TGs to become polyunsaturated as it does in the liver, without affecting lipolysis or composition of serum NEFAs. Changes in AT metabolism do not contribute to NAFLD in PNPLA3-I148M carriers.
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Affiliation(s)
- Sami Qadri
- Department of Medicine, University of Helsinki and Helsinki University Hospital, Helsinki, Finland.,Minerva Foundation Institute for Medical Research, Helsinki, Finland
| | - Susanna Lallukka-Brück
- Department of Medicine, University of Helsinki and Helsinki University Hospital, Helsinki, Finland.,Minerva Foundation Institute for Medical Research, Helsinki, Finland
| | - Panu K Luukkonen
- Department of Medicine, University of Helsinki and Helsinki University Hospital, Helsinki, Finland.,Minerva Foundation Institute for Medical Research, Helsinki, Finland
| | - You Zhou
- Minerva Foundation Institute for Medical Research, Helsinki, Finland.,Systems Immunity University Research Institute and Division of Infection and Immunity, School of Medicine, Cardiff University, Cardiff, UK
| | - Amalia Gastaldelli
- Institute of Clinical Physiology, National Research Council, Pisa, Italy
| | | | - Henna Sammalkorpi
- Department of Gastrointestinal Surgery, Abdominal Center, Helsinki University Hospital, Helsinki, Finland
| | - Anne Juuti
- Department of Gastrointestinal Surgery, Abdominal Center, Helsinki University Hospital, Helsinki, Finland
| | - Anne K Penttilä
- Department of Gastrointestinal Surgery, Abdominal Center, Helsinki University Hospital, Helsinki, Finland
| | - Julia Perttilä
- Minerva Foundation Institute for Medical Research, Helsinki, Finland
| | - Antti Hakkarainen
- HUS Medical Imaging Center, Helsinki University Hospital, Helsinki, Finland
| | - Tiina E Lehtimäki
- HUS Medical Imaging Center, Helsinki University Hospital, Helsinki, Finland
| | - Matej Orešič
- Department of Chemistry, Örebro University, Örebro, Sweden
| | | | - Leanne Hodson
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Oxford, UK.,National Institute for Health Research Oxford Biomedical Research Centre, Oxford University Hospitals Foundation Trust, Oxford, UK
| | - Vesa M Olkkonen
- Minerva Foundation Institute for Medical Research, Helsinki, Finland
| | - Hannele Yki-Järvinen
- Department of Medicine, University of Helsinki and Helsinki University Hospital, Helsinki, Finland.,Minerva Foundation Institute for Medical Research, Helsinki, Finland
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Othonos N, Marjot T, Woods C, Hazlehurst JM, Nikolaou N, Pofi R, White S, Bonaventura I, Webster C, Duffy J, Cornfield T, Moolla A, Isidori AM, Hodson L, Tomlinson JW. Co-administration of 5α-reductase Inhibitors Worsens the Adverse Metabolic Effects of Prescribed Glucocorticoids. J Clin Endocrinol Metab 2020; 105:5864156. [PMID: 32594135 PMCID: PMC7500580 DOI: 10.1210/clinem/dgaa408] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/26/2019] [Accepted: 06/28/2020] [Indexed: 12/20/2022]
Abstract
CONTEXT Glucocorticoids (GCs) are commonly prescribed, but their use is associated with adverse metabolic effects. 5α-reductase inhibitors (5α-RI) are also frequently prescribed, mainly to inhibit testosterone conversion to dihydrotestosterone. However, they also prevent the inactivation of GCs. OBJECTIVE We hypothesized that 5α-RI may worsen the adverse effects of GCs. DESIGN Prospective, randomized study. PATIENTS A total of 19 healthy male volunteers (age 45 ± 2 years; body mass index 27.1 ± 0.7kg/m2). INTERVENTIONS Participants underwent metabolic assessments; 2-step hyperinsulinemic, euglycemic clamp incorporating stable isotopes, adipose tissue microdialysis, and biopsy. Participants were then randomized to either prednisolone (10 mg daily) or prednisolone (10 mg daily) plus a 5α-RI (finasteride 5 mg daily or dutasteride 0.5 mg daily) for 7 days; metabolic assessments were then repeated. MAIN OUTCOME MEASURES Ra glucose, glucose utilization (M-value), glucose oxidation, and nonesterified fatty acids (NEFA) levels. RESULTS Co-administration of prednisolone with a 5α-RI increased circulating prednisolone levels (482 ± 96 vs 761 ± 57 nmol/L, P = 0.029). Prednisolone alone did not alter Ra glucose (2.55 ± 0.34 vs 2.62 ± 0.19 mg/kg/minute, P = 0.86), M-value (3.2 ± 0.5 vs 2.7 ± 0.7 mg/kg/minute, P = 0.37), or glucose oxidation (0.042 ± 0.007 vs 0.040 ± 0.004 mmol/hr/kg/minute, P = 0.79). However, co-administration with a 5α-RI increased Ra glucose (2.67 ± 0.16 vs 3.05 ± 0.18 mg/kg/minute, P < 0.05) and decreased M-value (4.0 ± 0.5 vs 2.6 ± 0.4 mg/kg/minute, P < 0.05), and oxidation (0.043 ± 0.003 vs 0.036 ± 0.002 mmol/hr/kg, P < 0.01). Similarly, prednisolone did not impair insulin-mediated suppression of circulating NEFA (43.1 ± 28.9 vs 36.8 ± 14.3 μmol/L, P = 0.81), unless co-administered with a 5α-RI (49.8 ± 8.6 vs 88.5 ± 13.5 μmol/L, P < 0.01). CONCLUSIONS We have demonstrated that 5α-RIs exacerbate the adverse effects of prednisolone. This study has significant translational implications, including the need to consider GC dose adjustments, but also the necessity for increased vigilance for the development of adverse effects.
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Affiliation(s)
- Nantia Othonos
- Oxford Centre for Diabetes, Endocrinology and Metabolism, NIHR Oxford Biomedical Research Centre, University of Oxford, Churchill Hospital, Oxford, UK
| | - Thomas Marjot
- Translational Gastroenterology Unit, NIHR Oxford Biomedical Research Centre, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - Conor Woods
- Department of Endocrinology, Naas General Hospital, Kildare and Tallaght Hospital, Dublin, Ireland
| | - Jonathan M Hazlehurst
- Institute of Metabolism and Systems Research, University of Birmingham, Edgbaston, Birmingham, UK
| | - Nikolaos Nikolaou
- Oxford Centre for Diabetes, Endocrinology and Metabolism, NIHR Oxford Biomedical Research Centre, University of Oxford, Churchill Hospital, Oxford, UK
| | - Riccardo Pofi
- Department of Experimental Medicine, Sapienza University of Rome, Rome, 00161, Italy
| | - Sarah White
- Oxford Centre for Diabetes, Endocrinology and Metabolism, NIHR Oxford Biomedical Research Centre, University of Oxford, Churchill Hospital, Oxford, UK
| | - Ilaria Bonaventura
- Department of Experimental Medicine, Sapienza University of Rome, Rome, 00161, Italy
| | - Craig Webster
- Department of Pathology, University Hospitals Birmingham, NHS Foundation Trust, Birmingham, UK
| | - Joanne Duffy
- Department of Pathology, University Hospitals Birmingham, NHS Foundation Trust, Birmingham, UK
| | - Thomas Cornfield
- Oxford Centre for Diabetes, Endocrinology and Metabolism, NIHR Oxford Biomedical Research Centre, University of Oxford, Churchill Hospital, Oxford, UK
| | - Ahmad Moolla
- Oxford Centre for Diabetes, Endocrinology and Metabolism, NIHR Oxford Biomedical Research Centre, University of Oxford, Churchill Hospital, Oxford, UK
| | - Andrea M Isidori
- Department of Experimental Medicine, Sapienza University of Rome, Rome, 00161, Italy
| | - Leanne Hodson
- Oxford Centre for Diabetes, Endocrinology and Metabolism, NIHR Oxford Biomedical Research Centre, University of Oxford, Churchill Hospital, Oxford, UK
| | - Jeremy W Tomlinson
- Oxford Centre for Diabetes, Endocrinology and Metabolism, NIHR Oxford Biomedical Research Centre, University of Oxford, Churchill Hospital, Oxford, UK
- Correspondence and Reprint Requests: Professor Jeremy Tomlinson, Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Oxford OX3 7LJ, UK, E-mail:
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38
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Hodson L, Parry SA, Cornfield T, Charlton C, Low WS, Green CJ, Rosqvist F. Using total plasma triacylglycerol to assess hepatic de novo lipogenesis as an alternative to VLDL triacylglycerol. Ups J Med Sci 2020; 125:211-216. [PMID: 32208800 PMCID: PMC7446043 DOI: 10.1080/03009734.2020.1739789] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 03/02/2020] [Accepted: 03/04/2020] [Indexed: 12/22/2022] Open
Abstract
Background: Hepatic de novo lipogenesis (DNL) is ideally measured in very low-density lipoprotein (VLDL)-triacylglycerol (TAG). In the fasting state, the majority of plasma TAG typically represents VLDL-TAG; however, the merits of measuring DNL in total plasma TAG have not been assessed. This study aimed to assess the performance of DNL measured in VLDL-TAG (DNLVLDL-TAG) compared to that measured in total plasma TAG (DNLPlasma-TAG).Methods: Using deuterated water, newly synthesised palmitate was determined in fasting plasma VLDL-TAG and total TAG in 63 subjects taking part in multiple studies resulting in n = 123 assessments of DNL (%new palmitate of total palmitate). Subjects were split into tertiles to investigate if DNLPlasma-TAG could correctly classify subjects having 'high' (top tertile) and 'low' (bottom tertile) DNL. Repeatability was assessed in a subgroup (n = 16) with repeat visits.Results: DNLVLDL-TAG was 6.8% (IQR 3.6-10.7%) and DNLPlasma-TAG was 7.5% (IQR 4.0%-11.0%), and the correlation between the methods was rs = 0.62 (p < 0.0001). Bland-Altman plots demonstrated similar performance (mean difference 0.81%, p = 0.09); however, the agreement interval was wide (-9.6% to 11.2%). Compared to DNLVLDL-TAG, 54% of subjects with low DNL were correctly classified, whilst 66% of subjects with high DNL were correctly classified using DNLPlasma-TAG. Repeatability was acceptable (i.e. not different) at the group level, but the majority of subjects had an intra-individual variability over 25%.Conclusion: DNL in total plasma TAG performed similarly to DNL in VLDL-TAG at the group level, but there was large variability at the individual level. We suggest that plasma TAG could be useful for comparing DNL between groups.
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Affiliation(s)
- Leanne Hodson
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, University of Oxford, Oxford, UK
- National Institute for Health Research Oxford Biomedical Research Centre, Oxford University Hospitals Foundation Trust, Oxford, UK
| | - Sion A. Parry
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, University of Oxford, Oxford, UK
| | - Thomas Cornfield
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, University of Oxford, Oxford, UK
| | - Catriona Charlton
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, University of Oxford, Oxford, UK
| | - Wee Suan Low
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, University of Oxford, Oxford, UK
| | - Charlotte J. Green
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, University of Oxford, Oxford, UK
| | - Fredrik Rosqvist
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, University of Oxford, Oxford, UK
- Department of Public Health and Caring Sciences, Clinical Nutrition and Metabolism, Uppsala University, Uppsala, Sweden
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Savic D, Hodson L, Neubauer S, Pavlides M. The Importance of the Fatty Acid Transporter L-Carnitine in Non-Alcoholic Fatty Liver Disease (NAFLD). Nutrients 2020; 12:E2178. [PMID: 32708036 PMCID: PMC7469009 DOI: 10.3390/nu12082178] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 07/17/2020] [Accepted: 07/20/2020] [Indexed: 12/16/2022] Open
Abstract
L-carnitine transports fatty acids into the mitochondria for oxidation and also buffers excess acetyl-CoA away from the mitochondria. Thus, L-carnitine may play a key role in maintaining liver function, by its effect on lipid metabolism. The importance of L-carnitine in liver health is supported by the observation that patients with primary carnitine deficiency (PCD) can present with fatty liver disease, which could be due to low levels of intrahepatic and serum levels of L-carnitine. Furthermore, studies suggest that supplementation with L-carnitine may reduce liver fat and the liver enzymes alanine aminotransferase (ALT) and aspartate transaminase (AST) in patients with Non-Alcoholic Fatty Liver Disease (NAFLD). L-carnitine has also been shown to improve insulin sensitivity and elevate pyruvate dehydrogenase (PDH) flux. Studies that show reduced intrahepatic fat and reduced liver enzymes after L-carnitine supplementation suggest that L-carnitine might be a promising supplement to improve or delay the progression of NAFLD.
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Affiliation(s)
- Dragana Savic
- Radcliffe Department of Medicine, Oxford Centre for Magnetic Resonance Research, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DU, UK; (S.N.); (M.P.)
| | - Leanne Hodson
- Radcliffe Department of Medicine, Oxford Centre for Diabetes, Endocrinology & Metabolism, Churchill Hospital, University of Oxford, Oxford OX3 7LE, UK;
- Oxford NIHR Biomedical Research Centre, University of Oxford, Oxford OX3 7LE, UK
| | - Stefan Neubauer
- Radcliffe Department of Medicine, Oxford Centre for Magnetic Resonance Research, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DU, UK; (S.N.); (M.P.)
| | - Michael Pavlides
- Radcliffe Department of Medicine, Oxford Centre for Magnetic Resonance Research, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DU, UK; (S.N.); (M.P.)
- Oxford NIHR Biomedical Research Centre, University of Oxford, Oxford OX3 7LE, UK
- Translational Gastroenterology Unit, University of Oxford, Oxford OX3 9DU, UK
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Gunn PJ, Pramfalk C, Millar V, Cornfield T, Hutchinson M, Johnson EM, Nagarajan SR, Troncoso‐Rey P, Mithen RF, Pinnick KE, Traka MH, Green CJ, Hodson L. Modifying nutritional substrates induces macrovesicular lipid droplet accumulation and metabolic alterations in a cellular model of hepatic steatosis. Physiol Rep 2020; 8:e14482. [PMID: 32643289 PMCID: PMC7343665 DOI: 10.14814/phy2.14482] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2020] [Revised: 05/02/2020] [Accepted: 05/18/2020] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND AND AIMS Nonalcoholic fatty liver disease (NAFLD) begins with steatosis, where a mixed macrovesicular pattern of large and small lipid droplets (LDs) develops. Since in vitro models recapitulating this are limited, the aims of this study were to develop mixed macrovesicular steatosis in immortalized hepatocytes and investigate effects on intracellular metabolism by altering nutritional substrates. METHODS Huh7 cells were cultured in 11 mM glucose and 2% human serum (HS) for 7 days before additional sugars and fatty acids (FAs), either with 200 µM FAs (low fat low sugar; LFLS), 5.5 mM fructose + 200 µM FAs (low fat high sugar; LFHS), or 5.5 mM fructose + 800 µM FAs (high fat high sugar; HFHS), were added for 7 days. FA metabolism, lipid droplet characteristics, and transcriptomic signatures were investigated. RESULTS Between the LFLS and LFHS conditions, there were few notable differences. In the HFHS condition, intracellular triacylglycerol (TAG) was increased and the LD pattern and distribution was similar to that found in primary steatotic hepatocytes. HFHS-treated cells had lower levels of de novo-derived FAs and secreted larger, TAG-rich lipoprotein particles. RNA sequencing and gene set enrichment analysis showed changes in several pathways including those involved in metabolism and cell cycle. CONCLUSIONS Repeated doses of HFHS treatment resulted in a cellular model of NAFLD with a mixed macrovesicular LD pattern and metabolic dysfunction. Since these nutrients have been implicated in the development of NAFLD in humans, the model provides a good physiological basis for studying NAFLD development or regression in vitro.
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Affiliation(s)
- Pippa J. Gunn
- Oxford Centre for Diabetes, Endocrinology and MetabolismRadcliffe Department of MedicineUniversity of OxfordOxfordUK
| | - Camilla Pramfalk
- Division of Clinical ChemistryDepartment of Laboratory MedicineKarolinska Institutet at Karolinska University Hospital HuddingeStockholmSweden
| | - Val Millar
- Target Discovery InstituteNuffield Department of MedicineUniversity of OxfordOxfordUK
| | - Thomas Cornfield
- Oxford Centre for Diabetes, Endocrinology and MetabolismRadcliffe Department of MedicineUniversity of OxfordOxfordUK
| | - Matthew Hutchinson
- Oxford Centre for Diabetes, Endocrinology and MetabolismRadcliffe Department of MedicineUniversity of OxfordOxfordUK
| | - Elspeth M. Johnson
- Oxford Centre for Diabetes, Endocrinology and MetabolismRadcliffe Department of MedicineUniversity of OxfordOxfordUK
| | - Shilpa R. Nagarajan
- Oxford Centre for Diabetes, Endocrinology and MetabolismRadcliffe Department of MedicineUniversity of OxfordOxfordUK
| | | | | | - Katherine E. Pinnick
- Oxford Centre for Diabetes, Endocrinology and MetabolismRadcliffe Department of MedicineUniversity of OxfordOxfordUK
| | | | - Charlotte J. Green
- Oxford Centre for Diabetes, Endocrinology and MetabolismRadcliffe Department of MedicineUniversity of OxfordOxfordUK
| | - Leanne Hodson
- Oxford Centre for Diabetes, Endocrinology and MetabolismRadcliffe Department of MedicineUniversity of OxfordOxfordUK
- National Institute for Health Research Oxford Biomedical Research CentreOxford University Hospital TrustsOxfordUK
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Marjot T, Green CJ, Charlton CA, Cornfield T, Hazlehurst J, Moolla A, White S, Francis J, Neubauer S, Cobbold JFL, Hodson L, Tomlinson JW. Sodium-glucose cotransporter 2 inhibition does not reduce hepatic steatosis in overweight, insulin-resistant patients without type 2 diabetes. JGH Open 2020; 4:433-440. [PMID: 32514450 PMCID: PMC7273735 DOI: 10.1002/jgh3.12274] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Revised: 10/03/2019] [Accepted: 10/07/2019] [Indexed: 12/25/2022]
Abstract
BACKGROUND AND AIM Non-alcoholic fatty liver disease (NAFLD) is rapidly becoming the leading indication for liver transplant and is associated with increased cardiovascular and liver mortality, yet there are no licensed therapies. Sodium-glucose cotransporter 2 (SGLT2) inhibitors are widely used for their glucose-lowering effects in patients with type 2 diabetes (T2D). Preclinical models have suggested a beneficial impact on NAFLD, but clinical data are limited, and there are currently no data on patients without T2D. We aimed to investigate the impact of SGLT2 inhibition on NAFLD in overweight, nondiabetic patients and establish the effect these agents may have on the processes that regulate hepatic steatosis in vivo. METHODS We conducted an open-label, experimental medicine pilot study on insulin-resistant overweight/obese individuals (n = 10) using gold-standard noninvasive assessments of NAFLD phenotype, including magnetic resonance spectroscopy, two-step hyperinsulinemic euglycemic clamps, and stable isotope tracers to assess lipid and glucose metabolism. Investigations were performed before and after a 12-week treatment with the SGLT2 inhibitor, dapagliflozin. RESULTS Despite a body weight reduction of 4.4 kg, hepatic steatosis was unchanged following treatment. Hepatic glucose production increased, and there was impairment of glucose disposal during the low-dose insulin infusion. Although circulating, nonesterified, fatty acid levels did not change, the ability of insulin to suppress lipolysis was reduced. CONCLUSIONS SGLT2 inhibition for 12 weeks does not improve hepatic steatosis in patients without T2D. Additional studies in patients with established T2D or impairments of fasting or postprandial glucose homeostasis are needed to determine whether SGLT2 inhibition represents a viable therapeutic strategy for NAFLD. (http://clinicaltrials.gov Number NCT02696941).
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Affiliation(s)
- Thomas Marjot
- Translational Gastroenterology Unit, NIHR Oxford Biomedical Research CentreUniversity of Oxford, John Radcliffe HospitalOxfordUK
- Oxford Centre for Diabetes, Endocrinology and Metabolism, NIHR Oxford Biomedical Research CentreUniversity of Oxford, Churchill HospitalOxfordUK
| | - Charlotte J Green
- Oxford Centre for Diabetes, Endocrinology and Metabolism, NIHR Oxford Biomedical Research CentreUniversity of Oxford, Churchill HospitalOxfordUK
| | - Catriona A Charlton
- Oxford Centre for Diabetes, Endocrinology and Metabolism, NIHR Oxford Biomedical Research CentreUniversity of Oxford, Churchill HospitalOxfordUK
| | - Thomas Cornfield
- Oxford Centre for Diabetes, Endocrinology and Metabolism, NIHR Oxford Biomedical Research CentreUniversity of Oxford, Churchill HospitalOxfordUK
| | - Jonathan Hazlehurst
- Oxford Centre for Diabetes, Endocrinology and Metabolism, NIHR Oxford Biomedical Research CentreUniversity of Oxford, Churchill HospitalOxfordUK
- Institute of Metabolism and Systems ResearchUniversity of BirminghamBirminghamUK
- Centre of Endocrinology, Diabetes and MetabolismQueen Elizabeth Hospital Birmingham, Birmingham Health PartnersBirminghamUK
| | - Ahmad Moolla
- Oxford Centre for Diabetes, Endocrinology and Metabolism, NIHR Oxford Biomedical Research CentreUniversity of Oxford, Churchill HospitalOxfordUK
| | - Sarah White
- Oxford Centre for Diabetes, Endocrinology and Metabolism, NIHR Oxford Biomedical Research CentreUniversity of Oxford, Churchill HospitalOxfordUK
| | - Jane Francis
- Oxford Centre for Clinical Magnetic Resonance Research (OCMR), Division of Cardiovascular Medicine, Radcliffe Department of MedicineUniversity of OxfordOxfordUK
| | - Stefan Neubauer
- Oxford Centre for Clinical Magnetic Resonance Research (OCMR), Division of Cardiovascular Medicine, Radcliffe Department of MedicineUniversity of OxfordOxfordUK
| | - Jeremy FL Cobbold
- Translational Gastroenterology Unit, NIHR Oxford Biomedical Research CentreUniversity of Oxford, John Radcliffe HospitalOxfordUK
| | - Leanne Hodson
- Oxford Centre for Diabetes, Endocrinology and Metabolism, NIHR Oxford Biomedical Research CentreUniversity of Oxford, Churchill HospitalOxfordUK
| | - Jeremy W Tomlinson
- Oxford Centre for Diabetes, Endocrinology and Metabolism, NIHR Oxford Biomedical Research CentreUniversity of Oxford, Churchill HospitalOxfordUK
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42
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Abstract
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
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Affiliation(s)
- Leanne Hodson
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Headington, Oxford, UK.
- Oxford NIHR Biomedical Research Centre, Churchill Hospital, Headington, Oxford, UK.
| | - Pippa J Gunn
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Headington, Oxford, UK
- Oxford NIHR Biomedical Research Centre, Churchill Hospital, Headington, Oxford, UK
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43
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Nikolaou N, Arvaniti A, Appanna N, Sharp A, Hughes BA, Digweed D, Whitaker MJ, Ross R, Arlt W, Penning TM, Morris K, George S, Keevil BG, Hodson L, Gathercole LL, Tomlinson JW. Glucocorticoids regulate AKR1D1 activity in human liver in vitro and in vivo. J Endocrinol 2020; 245:207-218. [PMID: 32106090 PMCID: PMC7182088 DOI: 10.1530/joe-19-0473] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 02/27/2020] [Indexed: 12/14/2022]
Abstract
Steroid 5β-reductase (AKR1D1) is highly expressed in human liver where it inactivates endogenous glucocorticoids and catalyses an important step in bile acid synthesis. Endogenous and synthetic glucocorticoids are potent regulators of metabolic phenotype and play a crucial role in hepatic glucose metabolism. However, the potential of synthetic glucocorticoids to be metabolised by AKR1D1 as well as to regulate its expression and activity has not been investigated. The impact of glucocorticoids on AKR1D1 activity was assessed in human liver HepG2 and Huh7 cells; AKR1D1 expression was assessed by qPCR and Western blotting. Genetic manipulation of AKR1D1 expression was conducted in HepG2 and Huh7 cells and metabolic assessments were made using qPCR. Urinary steroid metabolite profiling in healthy volunteers was performed pre- and post-dexamethasone treatment, using gas chromatography-mass spectrometry. AKR1D1 metabolised endogenous cortisol, but cleared prednisolone and dexamethasone less efficiently. In vitro and in vivo, dexamethasone decreased AKR1D1 expression and activity, further limiting glucocorticoid clearance and augmenting action. Dexamethasone enhanced gluconeogenic and glycogen synthesis gene expression in liver cell models and these changes were mirrored by genetic knockdown of AKR1D1 expression. The effects of AKR1D1 knockdown were mediated through multiple nuclear hormone receptors, including the glucocorticoid, pregnane X and farnesoid X receptors. Glucocorticoids down-regulate AKR1D1 expression and activity and thereby reduce glucocorticoid clearance. In addition, AKR1D1 down-regulation alters the activation of multiple nuclear hormone receptors to drive changes in gluconeogenic and glycogen synthesis gene expression profiles, which may exacerbate the adverse impact of exogenous glucocorticoids.
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Affiliation(s)
- Nikolaos Nikolaou
- Oxford Centre for Diabetes,
Endocrinology and Metabolism, NIHR Oxford Biomedical Research Centre,
University of Oxford, Churchill Hospital, Oxford, UK
| | - Anastasia Arvaniti
- Oxford Centre for Diabetes,
Endocrinology and Metabolism, NIHR Oxford Biomedical Research Centre,
University of Oxford, Churchill Hospital, Oxford, UK
- Department of Biological and Medical
Sciences, Oxford Brookes University, Oxford,
UK
| | - Nathan Appanna
- Oxford Centre for Diabetes,
Endocrinology and Metabolism, NIHR Oxford Biomedical Research Centre,
University of Oxford, Churchill Hospital, Oxford, UK
| | - Anna Sharp
- Oxford Centre for Diabetes,
Endocrinology and Metabolism, NIHR Oxford Biomedical Research Centre,
University of Oxford, Churchill Hospital, Oxford, UK
| | - Beverly A Hughes
- Institute of Metabolism and Systems
Research, University of Birmingham, Edgbaston, Birmingham,
UK
| | | | | | - Richard Ross
- Department of Oncology and
Metabolism, Faculty of Medicine, Dentistry and Health,
University of Sheffield, Sheffield, UK
| | - Wiebke Arlt
- Institute of Metabolism and Systems
Research, University of Birmingham, Edgbaston, Birmingham,
UK
- NIHR Birmingham Biomedical Research
Centre, University Hospitals Birmingham NHS Foundation Trust
and University of Birmingham, Birmingham, UK
| | - Trevor M Penning
- Department of Systems Pharmacology &
Translational Therapeutics, University of Pennsylvania Perelman
School of Medicine, Philadelphia, Pennsylvania, USA
| | - Karen Morris
- Biochemistry Department,
Manchester University NHS Trust, Manchester, UK
| | - Sherly George
- Biochemistry Department,
Manchester University NHS Trust, Manchester, UK
| | - Brian G Keevil
- Biochemistry Department,
Manchester University NHS Trust, Manchester, UK
| | - Leanne Hodson
- Oxford Centre for Diabetes,
Endocrinology and Metabolism, NIHR Oxford Biomedical Research Centre,
University of Oxford, Churchill Hospital, Oxford, UK
| | - Laura L Gathercole
- Oxford Centre for Diabetes,
Endocrinology and Metabolism, NIHR Oxford Biomedical Research Centre,
University of Oxford, Churchill Hospital, Oxford, UK
- Department of Biological and Medical
Sciences, Oxford Brookes University, Oxford,
UK
| | - Jeremy W Tomlinson
- Oxford Centre for Diabetes,
Endocrinology and Metabolism, NIHR Oxford Biomedical Research Centre,
University of Oxford, Churchill Hospital, Oxford, UK
- Correspondence should be addressed to J W Tomlinson:
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Parry SA, Rosqvist F, Mozes FE, Cornfield T, Hutchinson M, Piche ME, Hülsmeier AJ, Hornemann T, Dyson P, Hodson L. Intrahepatic Fat and Postprandial Glycemia Increase After Consumption of a Diet Enriched in Saturated Fat Compared With Free Sugars. Diabetes Care 2020; 43:1134-1141. [PMID: 32165444 PMCID: PMC7171936 DOI: 10.2337/dc19-2331] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Accepted: 02/25/2020] [Indexed: 02/03/2023]
Abstract
OBJECTIVE Debate continues regarding the influence of dietary fats and sugars on the risk of developing metabolic diseases, including insulin resistance and nonalcoholic fatty liver disease (NAFLD). We investigated the effect of two eucaloric diets, one enriched with saturated fat (SFA) and the other enriched with free sugars (SUGAR), on intrahepatic triacylglycerol (IHTAG) content, hepatic de novo lipogenesis (DNL), and whole-body postprandial metabolism in overweight males. RESEARCH DESIGN AND METHODS Sixteen overweight males were randomized to consume the SFA or SUGAR diet for 4 weeks before consuming the alternate diet after a 7-week washout period. The metabolic effects of the respective diets on IHTAG content, hepatic DNL, and whole-body metabolism were investigated using imaging techniques and metabolic substrates labeled with stable-isotope tracers. RESULTS Consumption of the SFA diet significantly increased IHTAG by mean ± SEM 39.0 ± 10.0%, while after the SUGAR diet IHTAG was virtually unchanged. Consumption of the SFA diet induced an exaggerated postprandial glucose and insulin response to a standardized test meal compared with SUGAR. Although whole-body fat oxidation, lipolysis, and DNL were similar following the two diets, consumption of the SUGAR diet resulted in significant (P < 0.05) decreases in plasma total, HDL, and non-HDL cholesterol and fasting β-hydroxybutyrate plasma concentrations. CONCLUSIONS Consumption of an SFA diet had a potent effect, increasing IHTAG together with exaggerating postprandial glycemia. The SUGAR diet did not influence IHTAG and induced minor metabolic changes. Our findings indicate that a diet enriched in SFA is more harmful to metabolic health than a diet enriched in free sugars.
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Affiliation(s)
- Siôn A Parry
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford, U.K
| | - Fredrik Rosqvist
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford, U.K
- Department of Public Health and Caring Sciences, Clinical Nutrition and Metabolism, Uppsala University, Uppsala, Sweden
| | - Ferenc E Mozes
- Oxford Centre for Clinical Magnetic Resonance Research, University of Oxford, John Radcliffe Hospital, Oxford, U.K
| | - Thomas Cornfield
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford, U.K
| | - Matthew Hutchinson
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford, U.K
| | - Marie-Eve Piche
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford, U.K
- Quebec Heart and Lung Institute, Laval University, Quebec, Canada
| | - Andreas J Hülsmeier
- Institute for Clinical Chemistry, University Hospital Zurich and University of Zurich, Zurich, Switzerland
| | - Thorsten Hornemann
- Institute for Clinical Chemistry, University Hospital Zurich and University of Zurich, Zurich, Switzerland
| | - Pamela Dyson
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford, U.K
- National Institute for Health Research Oxford Biomedical Research Centre, Oxford University Hospital Trusts, Oxford, U.K
| | - Leanne Hodson
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford, U.K.
- National Institute for Health Research Oxford Biomedical Research Centre, Oxford University Hospital Trusts, Oxford, U.K
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Abstract
The prevalence of non-alcoholic fatty liver disease (NAFLD) and type 2 diabetes (T2D) is increasing. As a strong association between these two diseases exist, it is unsurprising that the number of patients with coexisting NAFLD and T2D is also increasing. These patients display a deleterious metabolic profile (e.g. hypertriglyceridemia), and increased mortality rates relative to those with only NAFLD or T2D in isolation; therefore, effective treatment strategies are required. Here we review the available intervention studies that have investigated the effects of changes in lifestyle (diet and exercise/physical activity) on NAFLD in patients with both NAFLD and T2D. On the basis of the available evidence, it appears that the addition of any kind of exercise (i.e. resistance, aerobic, or high-intensity intermittent exercise) is beneficial for patients with both NAFLD and T2D. These effects appear to occur independently of changes in body weight. Hypocaloric diets leading to weight loss are also effective in improving metabolic parameters in patients with both NAFLD and T2D, with data indicating that ~ 7–10% weight loss is required in order to observe beneficial effects. It is unclear if multidisciplinary interventions incorporating changes in both diet and physical activity levels are a more effective treatment strategy in this population than diet or exercise interventions in isolation. In conclusion, it is clear that lifestyle interventions are an effective treatment strategy in patients with both NAFLD and T2D, although further research is required to optimise these interventions and determine their scalability.
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Affiliation(s)
- Siôn A Parry
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford, UK.
| | - Leanne Hodson
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford, UK
- National Institute for Health Research Oxford Biomedical Research Centre, Oxford University Hospital Trusts, Oxford, UK
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Hodson L. The Olympic sport that influences my lab leadership style. Nature 2020:10.1038/d41586-020-00806-x. [PMID: 32203362 DOI: 10.1038/d41586-020-00806-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Luukkonen PK, Tukiainen T, Juuti A, Sammalkorpi H, Haridas PAN, Niemelä O, Arola J, Orho-Melander M, Hakkarainen A, Kovanen PT, Dwivedi O, Groop L, Hodson L, Gastaldelli A, Hyötyläinen T, Orešič M, Yki-Järvinen H. Hydroxysteroid 17-β dehydrogenase 13 variant increases phospholipids and protects against fibrosis in nonalcoholic fatty liver disease. JCI Insight 2020; 5:132158. [PMID: 32161197 DOI: 10.1172/jci.insight.132158] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Accepted: 02/05/2020] [Indexed: 12/22/2022] Open
Abstract
Carriers of the hydroxysteroid 17-β dehydrogenase 13 (HSD17B13) gene variant (rs72613567:TA) have a reduced risk of NASH and cirrhosis but not steatosis. We determined its effect on liver histology, lipidome, and transcriptome using ultra performance liquid chromatography-mass spectrometry and RNA-seq. In carriers and noncarriers of the gene variant, we also measured pathways of hepatic fatty acids (de novo lipogenesis [DNL] and adipose tissue lipolysis [ATL] using 2H2O and 2H-glycerol) and insulin sensitivity using 3H-glucose and euglycemic-hyperinsulinemic clamp) and plasma cytokines. Carriers and noncarriers had similar age, sex and BMI. Fibrosis was significantly less frequent while phospholipids, but not other lipids, were enriched in the liver in carriers compared with noncarriers. Expression of 274 genes was altered in carriers compared with noncarriers, consisting predominantly of downregulated inflammation-related gene sets. Plasma IL-6 concentrations were lower, but DNL, ATL and hepatic insulin sensitivity were similar between the groups. In conclusion, carriers of the HSD17B13 variant have decreased fibrosis and expression of inflammation-related genes but increased phospholipids in the liver. These changes are not secondary to steatosis, DNL, ATL, or hepatic insulin sensitivity. The increase in phospholipids and decrease in fibrosis are opposite to features of choline-deficient models of liver disease and suggest HSD17B13 as an attractive therapeutic target.
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Affiliation(s)
- Panu K Luukkonen
- Department of Medicine, University of Helsinki and Helsinki University Hospital, Helsinki, Finland.,Minerva Foundation Institute for Medical Research, Helsinki, Finland.,Yale School of Medicine, Yale University, New Haven, Connecticut, USA
| | - Taru Tukiainen
- Institute for Molecular Medicine Finland, Helsinki, Finland
| | - Anne Juuti
- Department of Surgery, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Henna Sammalkorpi
- Department of Surgery, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | | | - Onni Niemelä
- Department of Laboratory Medicine and Medical Research Unit, Seinäjoki Central Hospital and University of Tampere, Tampere, Finland
| | - Johanna Arola
- Department of Pathology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | | | - Antti Hakkarainen
- Department of Radiology, HUS Medical Imaging Center, Helsinki University Hospital and University of Helsinki, Helsinki, Finland.,Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Espoo, Finland
| | | | - Om Dwivedi
- Institute for Molecular Medicine Finland, Helsinki, Finland
| | - Leif Groop
- Institute for Molecular Medicine Finland, Helsinki, Finland.,Department of Clinical Sciences, Lund University, Malmö, Sweden
| | - Leanne Hodson
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Oxford, United Kingdom
| | - Amalia Gastaldelli
- Institute of Clinical Physiology, Consiglio Nazionale delle Ricerche, Pisa, Italy
| | | | - Matej Orešič
- Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, Turku, Finland.,School of Medical Sciences, Örebro University, Örebro, Sweden
| | - Hannele Yki-Järvinen
- Department of Medicine, University of Helsinki and Helsinki University Hospital, Helsinki, Finland.,Minerva Foundation Institute for Medical Research, Helsinki, Finland
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Green CJ, Pramfalk C, Charlton CA, Gunn PJ, Cornfield T, Pavlides M, Karpe F, Hodson L. Hepatic de novo lipogenesis is suppressed and fat oxidation is increased by omega-3 fatty acids at the expense of glucose metabolism. BMJ Open Diabetes Res Care 2020; 8:8/1/e000871. [PMID: 32188593 PMCID: PMC7078804 DOI: 10.1136/bmjdrc-2019-000871] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2019] [Revised: 02/07/2020] [Accepted: 02/20/2020] [Indexed: 12/12/2022] Open
Abstract
OBJECTIVE Increased hepatic de novo lipogenesis (DNL) is suggested to be an underlying cause in the development of nonalcoholic fatty liver disease and/or insulin resistance. It is suggested that omega-3 fatty acids (FA) lower hepatic DNL. We investigated the effects of omega-3 FA supplementation on hepatic DNL and FA oxidation using a combination of human in vivo and in vitro studies. RESEARCH DESIGN AND METHODS Thirty-eight healthy men were randomized to take either an omega-3 supplement (4 g/day eicosapentaenoic acid (EPA)+docosahexaenoic acid (DHA) as ethyl esters) or placebo (4 g/day olive oil) and fasting measurements were made at baseline and 8 weeks. The metabolic effects of omega-3 FAs on intrahepatocellular triacylglycerol (IHTAG) content, hepatic DNL and FA oxidation were investigated using metabolic substrates labeled with stable-isotope tracers. In vitro studies, using a human liver cell-line was undertaken to gain insight into the intrahepatocellular effects of omega-3 FAs. RESULTS Fasting plasma TAG concentrations significantly decreased in the omega-3 group and remained unchanged in the placebo group. Eight weeks of omega-3 supplementation significantly decreased IHTAG, fasting and postprandial hepatic DNL while significantly increasing dietary FA oxidation and fasting and postprandial plasma glucose concentrations. In vitro studies supported the in vivo findings of omega-3 FAs (EPA+DHA) decreasing intracellular TAG through a shift in cellular metabolism away from FA esterification toward oxidation. CONCLUSIONS Omega-3 supplementation had a potent effect on decreasing hepatic DNL and increasing FA oxidation and plasma glucose concentrations. Attenuation of hepatic DNL may be considered advantageous; however, consideration is required as to what the potential excess of nonlipid substrates (eg, glucose) will have on intrahepatic and extrahepatic metabolic pathways. TRIAL REGISTRATION NUMBER NCT01936779.
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Affiliation(s)
| | | | | | | | | | - Michael Pavlides
- University of Oxford, Oxford, Oxfordshire, UK
- Translational Gastroenterology Unit, John Radcliffe Hospital, Oxford, UK
| | - Fredrik Karpe
- University of Oxford, Oxford, Oxfordshire, UK
- National Institute for Health Research Oxford Biomedical Research Centre, Oxford University Hospitals Foundation Trust, Oxford, UK
| | - Leanne Hodson
- University of Oxford, Oxford, Oxfordshire, UK
- National Institute for Health Research Oxford Biomedical Research Centre, Oxford University Hospitals Foundation Trust, Oxford, UK
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Marjot T, Moolla A, Cobbold JF, Hodson L, Tomlinson JW. Nonalcoholic Fatty Liver Disease in Adults: Current Concepts in Etiology, Outcomes, and Management. Endocr Rev 2020; 41:5601173. [PMID: 31629366 DOI: 10.1210/endrev/bnz009] [Citation(s) in RCA: 118] [Impact Index Per Article: 29.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Accepted: 10/14/2019] [Indexed: 02/06/2023]
Abstract
Nonalcoholic fatty liver disease (NAFLD) is a spectrum of disease, extending from simple steatosis to inflammation and fibrosis with a significant risk for the development of cirrhosis. It is highly prevalent and is associated with significant adverse outcomes both through liver-specific morbidity and mortality but, perhaps more important, through adverse cardiovascular and metabolic outcomes. It is closely associated with type 2 diabetes and obesity, and both of these conditions drive progressive disease toward the more advanced stages. The mechanisms that govern hepatic lipid accumulation and the predisposition to inflammation and fibrosis are still not fully understood but reflect a complex interplay between metabolic target tissues including adipose and skeletal muscle, and immune and inflammatory cells. The ability to make an accurate assessment of disease stage (that relates to clinical outcome) can also be challenging. While liver biopsy is still regarded as the gold-standard investigative tool, there is an extensive literature on the search for novel noninvasive biomarkers and imaging modalities that aim to accurately reflect the stage of underlying disease. Finally, although no therapies are currently licensed for the treatment of NAFLD, there are interventions that appear to have proven efficacy in randomized controlled trials as well as an extensive emerging therapeutic landscape of new agents that target many of the fundamental pathophysiological processes that drive NAFLD. It is highly likely that over the next few years, new treatments with a specific license for the treatment of NAFLD will become available.
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Affiliation(s)
- Thomas Marjot
- Translational Gastroenterology Unit, NIHR Oxford Biomedical Research Centre, University of Oxford, John Radcliffe Hospital, Oxford, UK.,Oxford Centre for Diabetes, Endocrinology and Metabolism, NIHR Oxford Biomedical Research Centre, University of Oxford, Churchill Hospital, Oxford, UK
| | - Ahmad Moolla
- Oxford Centre for Diabetes, Endocrinology and Metabolism, NIHR Oxford Biomedical Research Centre, University of Oxford, Churchill Hospital, Oxford, UK
| | - Jeremy F Cobbold
- Translational Gastroenterology Unit, NIHR Oxford Biomedical Research Centre, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - Leanne Hodson
- Oxford Centre for Diabetes, Endocrinology and Metabolism, NIHR Oxford Biomedical Research Centre, University of Oxford, Churchill Hospital, Oxford, UK
| | - Jeremy W Tomlinson
- Oxford Centre for Diabetes, Endocrinology and Metabolism, NIHR Oxford Biomedical Research Centre, University of Oxford, Churchill Hospital, Oxford, UK
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Abstract
Nonalcoholic fatty liver disease (NAFLD) is an increasing global public health burden. NAFLD is strongly associated with type 2 diabetes mellitus, obesity and cardiovascular disease and begins with intrahepatic triacylglycerol accumulation. Under healthy conditions, the liver regulates lipid metabolism to meet systemic energy needs in the fed and fasted states. The processes of fatty acid uptake, fatty acid synthesis and the intracellular partitioning of fatty acids into storage, oxidation and secretion pathways are tightly regulated. When one or more of these processes becomes dysregulated, excess lipid accumulation can occur. Although genetic and environmental factors have been implicated in the development of NAFLD, it remains unclear why an imbalance in these pathways begins. The regulation of fatty acid partitioning occurs at several points, including during triacylglycerol synthesis, lipid droplet formation and lipolysis. These processes are influenced by enzyme function, intake of dietary fats and sugars and whole-body metabolism, and are further affected by the presence of obesity or insulin resistance. Insight into how the liver controls fatty acid metabolism in health and how these processes might be affected in disease would offer the potential for new therapeutic treatments for NAFLD to be developed.
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Affiliation(s)
- Leanne Hodson
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Headington, Oxford, UK.
- Oxford NIHR Biomedical Research Centre, Churchill Hospital, Headington, Oxford, UK.
| | - Pippa J Gunn
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Headington, Oxford, UK
- Oxford NIHR Biomedical Research Centre, Churchill Hospital, Headington, Oxford, UK
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