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Cook JR, Kohan AB, Haeusler RA. An Updated Perspective on the Dual-Track Model of Enterocyte Fat Metabolism. J Lipid Res 2022; 63:100278. [PMID: 36100090 PMCID: PMC9593242 DOI: 10.1016/j.jlr.2022.100278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 08/08/2022] [Accepted: 08/31/2022] [Indexed: 02/04/2023] Open
Abstract
The small intestinal epithelium has classically been envisioned as a conduit for nutrient absorption, but appreciation is growing for a larger and more dynamic role for enterocytes in lipid metabolism. Considerable gaps remain in our knowledge of this physiology, but it appears that the enterocyte's structural polarization dictates its behavior in fat partitioning, treating fat differently based on its absorption across the apical versus the basolateral membrane. In this review, we synthesize existing data and thought on this dual-track model of enterocyte fat metabolism through the lens of human integrative physiology. The apical track includes the canonical pathway of dietary lipid absorption across the apical brush-border membrane, leading to packaging and secretion of those lipids as chylomicrons. However, this track also reserves a portion of dietary lipid within cytoplasmic lipid droplets for later uses, including the "second-meal effect," which remains poorly understood. At the same time, the enterocyte takes up circulating fats across the basolateral membrane by mechanisms that may include receptor-mediated import of triglyceride-rich lipoproteins or their remnants, local hydrolysis and internalization of free fatty acids, or enterocyte de novo lipogenesis using basolaterally absorbed substrates. The ultimate destinations of basolateral-track fat may include fatty acid oxidation, structural lipid synthesis, storage in cytoplasmic lipid droplets, or ultimate resecretion, although the regulation and purposes of this basolateral track remain mysterious. We propose that the enterocyte integrates lipid flux along both of these tracks in order to calibrate its overall program of lipid metabolism.
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Affiliation(s)
- Joshua R. Cook
- Naomi Berrie Diabetes Center, Columbia University College of Physicians and Surgeons, New York, NY, USA,Division of Endocrinology, Diabetes & Metabolism, Department of Medicine, Columbia University College of Physicians and Surgeons, New York, NY, USA
| | - Alison B. Kohan
- Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Rebecca A. Haeusler
- Naomi Berrie Diabetes Center, Columbia University College of Physicians and Surgeons, New York, NY, USA,Department of Pathology and Cell Biology; Columbia University College of Physicians and Surgeons, New York, NY, USA,For correspondence: Rebecca A. Haeusler
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2
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Guerbette T, Boudry G, Lan A. Mitochondrial function in intestinal epithelium homeostasis and modulation in diet-induced obesity. Mol Metab 2022; 63:101546. [PMID: 35817394 PMCID: PMC9305624 DOI: 10.1016/j.molmet.2022.101546] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 06/27/2022] [Accepted: 07/06/2022] [Indexed: 11/30/2022] Open
Abstract
Background Systemic low-grade inflammation observed in diet-induced obesity has been associated with dysbiosis and disturbance of intestinal homeostasis. This latter relies on an efficient epithelial barrier and coordinated intestinal epithelial cell (IEC) renewal that are supported by their mitochondrial function. However, IEC mitochondrial function might be impaired by high fat diet (HFD) consumption, notably through gut-derived metabolite production and fatty acids, that may act as metabolic perturbators of IEC. Scope of review This review presents the current general knowledge on mitochondria, before focusing on IEC mitochondrial function and its role in the control of intestinal homeostasis, and featuring the known effects of nutrients and metabolites, originating from the diet or gut bacterial metabolism, on IEC mitochondrial function. It then summarizes the impact of HFD on mitochondrial function in IEC of both small intestine and colon and discusses the possible link between mitochondrial dysfunction and altered intestinal homeostasis in diet-induced obesity. Major conclusions HFD consumption provokes a metabolic shift toward fatty acid β-oxidation in the small intestine epithelial cells and impairs colonocyte mitochondrial function, possibly through downstream consequences of excessive fatty acid β-oxidation and/or the presence of deleterious metabolites produced by the gut microbiota. Decreased levels of ATP and concomitant O2 leaks into the intestinal lumen could explain the alterations of intestinal epithelium dynamics, barrier disruption and dysbiosis that contribute to the loss of epithelial homeostasis in diet-induced obesity. However, the effect of HFD on IEC mitochondrial function in the small intestine remains unknown and the precise mechanisms by which HFD induces mitochondrial dysfunction in the colon have not been elucidated so far.
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Affiliation(s)
| | - Gaëlle Boudry
- Institut Numecan, INSERM, INRAE, Univ Rennes, Rennes, France.
| | - Annaïg Lan
- Institut Numecan, INSERM, INRAE, Univ Rennes, Rennes, France; Université Paris-Saclay, AgroParisTech, INRAE, UMR PNCA, Paris, France
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3
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Holm S, Husted AS, Skov LJ, Morville TH, Hagemann CA, Jorsal T, Dall M, Jakobsen A, Klein AB, Treebak JT, Knop FK, Schwartz TW, Clemmensen C, Holst B. Beta-Hydroxybutyrate Suppresses Hepatic Production of the Ghrelin Receptor Antagonist LEAP2. Endocrinology 2022; 163:6555773. [PMID: 35352108 PMCID: PMC9119693 DOI: 10.1210/endocr/bqac038] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Indexed: 11/19/2022]
Abstract
INTRODUCTION Liver-expressed antimicrobial peptide-2 (LEAP2) is an endogenous ghrelin receptor antagonist, which is upregulated in the fed state and downregulated during fasting. We hypothesized that the ketone body beta-hydroxybutyrate (BHB) is involved in the downregulation of LEAP2 during conditions with high circulating levels of BHB. METHODS Hepatic and intestinal Leap2 expression were determined in 3 groups of mice with increasing circulating levels of BHB: prolonged fasting, prolonged ketogenic diet, and oral BHB treatment. LEAP2 levels were measured in lean and obese individuals, in human individuals following endurance exercise, and in mice after BHB treatment. Lastly, we investigated Leap2 expression in isolated murine hepatocytes challenged with BHB. RESULTS We confirmed increased circulating LEAP2 levels in individuals with obesity compared to lean individuals. The recovery period after endurance exercise was associated with increased plasma levels of BHB levels and decreased LEAP2 levels in humans. Leap2 expression was selectively decreased in the liver after fasting and after exposure to a ketogenic diet for 3 weeks. Importantly, we found that oral administration of BHB increased circulating levels of BHB in mice and decreased Leap2 expression levels and circulating LEAP2 plasma levels, as did Leap2 expression after direct exposure to BHB in isolated murine hepatocytes. CONCLUSION From our data, we suggest that LEAP2 is downregulated during different states of energy deprivation in both humans and rodents. Furthermore, we here provide evidence that the ketone body, BHB, which is highly upregulated during fasting metabolism, directly downregulates LEAP2 levels. This may be relevant in ghrelin receptor-induced hunger signaling during energy deprivation.
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Affiliation(s)
- Stephanie Holm
- Correspondence: Stephanie Holm, MSc, Novo Nordisk Foundation Center for Basic Metabolic Research (6th floor) & Department of Biomedical Sciences, Faculty of Health and Medical Sciences, Blegdamsvej 3B, 2200 Copenhagen, Denmark.
| | - Anna S Husted
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Louise J Skov
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Thomas H Morville
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Christoffer A Hagemann
- Center for Clinical Metabolic Research, Copenhagen University Hospital—Herlev and Gentofte, 2900 Hellerup, Denmark
- Gubra, 2970 Hørsholm, Denmark
| | - Tina Jorsal
- Center for Clinical Metabolic Research, Copenhagen University Hospital—Herlev and Gentofte, 2900 Hellerup, Denmark
| | - Morten Dall
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Alexander Jakobsen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Anders B Klein
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Jonas T Treebak
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Filip K Knop
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
- Center for Clinical Metabolic Research, Copenhagen University Hospital—Herlev and Gentofte, 2900 Hellerup, Denmark
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
- Steno Diabetes Center Copenhagen, 2730 Herlev, Denmark
| | - Thue W Schwartz
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Christoffer Clemmensen
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Birgitte Holst
- Correspondence: Birgitte Holst MD, PhD, Department of Biomedical Sciences, Faculty of Health and Medical Sciences, Blegdamsvej 3B, 2200 Copenhagen, Denmark.
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Petersen N, Greiner TU, Torz L, Bookout A, Gerstenberg MK, Castorena CM, Kuhre RE. Targeting the Gut in Obesity: Signals from the Inner Surface. Metabolites 2022; 12:metabo12010039. [PMID: 35050161 PMCID: PMC8778595 DOI: 10.3390/metabo12010039] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2021] [Revised: 12/26/2021] [Accepted: 12/31/2021] [Indexed: 12/17/2022] Open
Abstract
Obesity is caused by prolonged energy surplus. Current anti-obesity medications are mostly centralized around the energy input part of the energy balance equation by increasing satiety and reducing appetite. Our gastrointestinal tract is a key organ for regulation of food intake and supplies a tremendous number of circulating signals that modulate the activity of appetite-regulating areas of the brain by either direct interaction or through the vagus nerve. Intestinally derived messengers are manifold and include absorbed nutrients, microbial metabolites, gut hormones and other enterokines, collectively comprising a fine-tuned signalling system to the brain. After a meal, nutrients directly interact with appetite-inhibiting areas of the brain and induce satiety. However, overall feeding behaviour also depends on secretion of gut hormones produced by highly specialized and sensitive enteroendocrine cells. Moreover, circulating microbial metabolites and their interactions with enteroendocrine cells further contribute to the regulation of feeding patterns. Current therapies exploiting the appetite-regulating properties of the gut are based on chemically modified versions of the gut hormone, glucagon-like peptide-1 (GLP-1) or on inhibitors of the primary GLP-1 inactivating enzyme, dipeptidyl peptidase-4 (DPP-4). The effectiveness of these approaches shows that that the gut is a promising target for therapeutic interventions to achieve significant weigh loss. We believe that increasing understanding of the functionality of the intestinal epithelium and new delivery systems will help develop selective and safe gut-based therapeutic strategies for improved obesity treatment in the future. Here, we provide an overview of the major homeostatic appetite-regulating signals generated by the intestinal epithelial cells and how these signals may be harnessed to treat obesity by pharmacological means.
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Affiliation(s)
- Natalia Petersen
- Global Obesity and Liver Disease Research, Global Drug Discovery, Novo Nordisk A/S, Novo Park 1, 2670 Måløv, Denmark; (L.T.); (M.K.G.); (R.E.K.)
- Correspondence:
| | - Thomas U. Greiner
- The Wallenberg Laboratory and Sahlgrenska Center for Cardiovascular and Metabolic Research, Department of Molecular and Clinical Medicine, Institute of Medicine, University of Gothenburg, 405 30 Gothenburg, Sweden;
| | - Lola Torz
- Global Obesity and Liver Disease Research, Global Drug Discovery, Novo Nordisk A/S, Novo Park 1, 2670 Måløv, Denmark; (L.T.); (M.K.G.); (R.E.K.)
- Department of Veterinary and Animal Science, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Angie Bookout
- Global Obesity and Liver Disease Research, Global Drug Discovery, Novo Nordisk Research Center, Seattle, WA 98109, USA; (A.B.); (C.M.C.)
| | - Marina Kjærgaard Gerstenberg
- Global Obesity and Liver Disease Research, Global Drug Discovery, Novo Nordisk A/S, Novo Park 1, 2670 Måløv, Denmark; (L.T.); (M.K.G.); (R.E.K.)
| | - Carlos M. Castorena
- Global Obesity and Liver Disease Research, Global Drug Discovery, Novo Nordisk Research Center, Seattle, WA 98109, USA; (A.B.); (C.M.C.)
| | - Rune Ehrenreich Kuhre
- Global Obesity and Liver Disease Research, Global Drug Discovery, Novo Nordisk A/S, Novo Park 1, 2670 Måløv, Denmark; (L.T.); (M.K.G.); (R.E.K.)
- Department of Veterinary and Animal Science, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
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Zietek T, Boomgaarden WAD, Rath E. Drug Screening, Oral Bioavailability and Regulatory Aspects: A Need for Human Organoids. Pharmaceutics 2021; 13:1280. [PMID: 34452240 PMCID: PMC8399541 DOI: 10.3390/pharmaceutics13081280] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 08/12/2021] [Accepted: 08/14/2021] [Indexed: 12/31/2022] Open
Abstract
The intestinal epithelium critically contributes to oral bioavailability of drugs by constituting an important site for drug absorption and metabolism. In particular, intestinal epithelial cells (IEC) actively serve as gatekeepers of drug and nutrient availability. IECs' transport processes and metabolism are interrelated to the whole-body metabolic state and represent potential points of origin as well as therapeutic targets for a variety of diseases. Human intestinal organoids represent a superior model of the intestinal epithelium, overcoming limitations of currently used in vitro models. Caco-2 cells or rodent explant models face drawbacks such as their cancer and non-human origin, respectively, but are commonly used to study intestinal nutrient absorption, enterocyte metabolism and oral drug bioavailability, despite poorly correlative data. In contrast, intestinal organoids allow investigating distinct aspects of bioavailability including spatial resolution of transport, inter-individual differences and high-throughput screenings. As several countries have already developed strategic roadmaps to phase out animal experiments for regulatory purposes, intestinal organoid culture and organ-on-a-chip technology in combination with in silico approaches are roads to go in the preclinical and regulatory setup and will aid implementing the 3Rs (reduction, refinement and replacement) principle in basic science.
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Affiliation(s)
- Tamara Zietek
- Doctors against Animal Experiments, 51143 Köln, Germany
| | | | - Eva Rath
- Chair of Nutrition and Immunology, Technische Universität München, 85354 Freising, Germany
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Zembroski AS, Xiao C, Buhman KK. The Roles of Cytoplasmic Lipid Droplets in Modulating Intestinal Uptake of Dietary Fat. Annu Rev Nutr 2021; 41:79-104. [PMID: 34283920 DOI: 10.1146/annurev-nutr-110320-013657] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Dietary fat absorption is required for health but also contributes to hyperlipidemia and metabolic disease when dysregulated. One step in the process of dietary fat absorption is the formation of cytoplasmic lipid droplets (CLDs) in small intestinal enterocytes; these CLDs serve as dynamic triacylglycerol storage organelles that influence the rate at which dietary fat is absorbed. Recent studies have uncovered novel factors regulating enterocyte CLD metabolism that in turn influence the absorption of dietary fat. These include peroxisome proliferator-activated receptor α activation, compartmentalization of different lipid pools, the gut microbiome, liver X receptor and farnesoid X receptor activation, obesity, and physiological factors stimulating CLD mobilization. Understanding how enterocyte CLD metabolism is regulated is key in modulating the absorption of dietary fat in the prevention of hyperlipidemia and its associated metabolic disorders. Expected final online publication date for the Annual Review of Nutrition, Volume 41 is September 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Alyssa S Zembroski
- Department of Nutrition Science, Purdue University, West Lafayette, Indiana 47907, USA;
| | - Changting Xiao
- Department of Anatomy, Physiology and Pharmacology, College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E5, Canada
| | - Kimberly K Buhman
- Department of Nutrition Science, Purdue University, West Lafayette, Indiana 47907, USA;
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Zembroski AS, D’Aquila T, Buhman KK. Characterization of cytoplasmic lipid droplets in each region of the small intestine of lean and diet-induced obese mice in response to dietary fat. Am J Physiol Gastrointest Liver Physiol 2021; 321:G75-G86. [PMID: 34009042 PMCID: PMC8321799 DOI: 10.1152/ajpgi.00084.2021] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The absorptive cells of the small intestine, namely, enterocytes, contribute to postprandial blood lipid levels by secreting dietary triacylglycerol in chylomicrons. The rate and amount of dietary triacylglycerol absorbed vary along the length of the small intestine. Excess dietary triacylglycerol not immediately secreted in chylomicrons can be temporarily stored in cytoplasmic lipid droplets (CLDs) and repackaged in chylomicrons at later times. The characteristics of CLDs, including their size, number per cell, and associated proteins, may influence CLD metabolism and reflect differences in lipid processing or storage in each intestinal region. However, it is unknown whether the characteristics or proteomes of CLDs differ in enterocytes of each intestine region in response to dietary fat. Furthermore, it is unclear if obesity influences the characteristics or proteomes of CLDs in each intestine region. To address this, we used transmission electron microscopy and shotgun liquid chromatography tandem mass spectrometry (LC-MS/MS) analysis to assess the characteristics and proteome of CLDs in the proximal, middle, and distal regions of the small intestine of lean and diet-induced obese (DIO) mice 2 h after an oil gavage. We identified differences in lipid storage along the length of the small intestine and between lean and DIO mice, as well as distinct CLD proteomes reflecting potentially unique roles of CLDs in each region. This study reveals differences in lipid processing along the length of the small intestine in response to dietary fat in lean and DIO mice and reflects distinct features of the proximal, middle, distal region of the small intestine.NEW & NOTEWORTHY This study reflects the dynamics of fat absorption along the length of the small intestine in lean and obese mice in the physiological response to dietary fat. We identified unique features of cytoplasmic lipid droplets (CLDs) in the proximal, middle, and distal regions of the small intestine of lean and obese mice that may contribute to regional differences in dietary fat processing, absorption, or CLD metabolism.
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Affiliation(s)
| | - Theresa D’Aquila
- Department of Nutrition Science, Purdue University, West Lafayette, Indiana
| | - Kimberly K. Buhman
- Department of Nutrition Science, Purdue University, West Lafayette, Indiana
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8
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Zietek T, Giesbertz P, Ewers M, Reichart F, Weinmüller M, Urbauer E, Haller D, Demir IE, Ceyhan GO, Kessler H, Rath E. Organoids to Study Intestinal Nutrient Transport, Drug Uptake and Metabolism - Update to the Human Model and Expansion of Applications. Front Bioeng Biotechnol 2020; 8:577656. [PMID: 33015026 PMCID: PMC7516017 DOI: 10.3389/fbioe.2020.577656] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 08/19/2020] [Indexed: 12/22/2022] Open
Abstract
Intestinal transport and sensing processes and their interconnection to metabolism are relevant to pathologies such as malabsorption syndromes, inflammatory diseases, obesity and type 2 diabetes. Constituting a highly selective barrier, intestinal epithelial cells absorb, metabolize, and release nutrients into the circulation, hence serving as gatekeeper of nutrient availability and metabolic health for the whole organism. Next to nutrient transport and sensing functions, intestinal transporters including peptide transporter 1 (PEPT1) are involved in the absorption of drugs and prodrugs, including certain inhibitors of angiotensin-converting enzyme, protease inhibitors, antivirals, and peptidomimetics like β-lactam antibiotics. Here, we verify the applicability of 3D organoids for in vitro investigation of intestinal biochemical processes related to transport and metabolism of nutrients and drugs. Establishing a variety of methodologies including illustration of transporter-mediated nutrient and drug uptake and metabolomics approaches, we highlight intestinal organoids as robust and reliable tool in this field of research. Currently used in vitro models to study intestinal nutrient absorption, drug transport and enterocyte metabolism, such as Caco-2 cells or rodent explant models are of limited value due to their cancer and non-human origin, respectively. Particularly species differences result in poorly correlative data and findings obtained in these models cannot be extrapolated reliably to humans, as indicated by high failure rates in drug development pipelines. In contrast, human intestinal organoids represent a superior model of the intestinal epithelium and might help to implement the 3Rs (Reduction, Refinement and Replacement) principle in basic science as well as the preclinical and regulatory setup.
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Affiliation(s)
- Tamara Zietek
- Chair of Nutritional Physiology, Technische Universität München, Munich, Germany
| | - Pieter Giesbertz
- Chair of Nutritional Physiology, Technische Universität München, Munich, Germany
| | - Maren Ewers
- Pediatric Nutritional Medicine, Klinikum Rechts der Isar, Else Kröner-Fresenius-Zentrum für Ernährungsmedizin, Technische Universität München, Munich, Germany
| | - Florian Reichart
- Institute for Advanced Study, Department of Chemistry and Center for Integrated Protein Science (CIPSM), Technische Universität München, Garching, Germany
| | - Michael Weinmüller
- Institute for Advanced Study, Department of Chemistry and Center for Integrated Protein Science (CIPSM), Technische Universität München, Garching, Germany
| | - Elisabeth Urbauer
- Chair of Nutrition and Immunology, Technische Universität München, Munich, Germany
| | - Dirk Haller
- Chair of Nutrition and Immunology, Technische Universität München, Munich, Germany.,ZIEL Institute for Food and Health, Technische Universität München, Munich, Germany
| | - Ihsan Ekin Demir
- Department of Surgery, Klinikum Rechts der Isar, Technische Universität München, Munich, Germany.,Department of General Surgery, HPB-Unit, School of Medicine, Acibadem Mehmet Ali Aydinlar University, Istanbul, Turkey.,German Cancer Consortium (DKTK), Munich, Germany.,CRC 1321 Modeling and Targeting Pancreatic Cancer, Klinikum rechts der Isar, School of Medicine, Technische Universität München, Munich, Germany
| | - Güralp O Ceyhan
- Department of Surgery, Klinikum Rechts der Isar, Technische Universität München, Munich, Germany.,Department of General Surgery, HPB-Unit, School of Medicine, Acibadem Mehmet Ali Aydinlar University, Istanbul, Turkey
| | - Horst Kessler
- Institute for Advanced Study, Department of Chemistry and Center for Integrated Protein Science (CIPSM), Technische Universität München, Garching, Germany
| | - Eva Rath
- Chair of Nutrition and Immunology, Technische Universität München, Munich, Germany
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Kroupova P, van Schothorst EM, Keijer J, Bunschoten A, Vodicka M, Irodenko I, Oseeva M, Zacek P, Kopecky J, Rossmeisl M, Horakova O. Omega-3 Phospholipids from Krill Oil Enhance Intestinal Fatty Acid Oxidation More Effectively than Omega-3 Triacylglycerols in High-Fat Diet-Fed Obese Mice. Nutrients 2020; 12:nu12072037. [PMID: 32660007 PMCID: PMC7400938 DOI: 10.3390/nu12072037] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 07/03/2020] [Accepted: 07/06/2020] [Indexed: 12/19/2022] Open
Abstract
Antisteatotic effects of omega-3 fatty acids (Omega-3) in obese rodents seem to vary depending on the lipid form of their administration. Whether these effects could reflect changes in intestinal metabolism is unknown. Here, we compare Omega-3-containing phospholipids (krill oil; ω3PL-H) and triacylglycerols (ω3TG) in terms of their effects on morphology, gene expression and fatty acid (FA) oxidation in the small intestine. Male C57BL/6N mice were fed for 8 weeks with a high-fat diet (HFD) alone or supplemented with 30 mg/g diet of ω3TG or ω3PL-H. Omega-3 index, reflecting the bioavailability of Omega-3, reached 12.5% and 7.5% in the ω3PL-H and ω3TG groups, respectively. Compared to HFD mice, ω3PL-H but not ω3TG animals had lower body weight gain (−40%), mesenteric adipose tissue (−43%), and hepatic lipid content (−64%). The highest number and expression level of regulated intestinal genes was observed in ω3PL-H mice. The expression of FA ω-oxidation genes was enhanced in both Omega-3-supplemented groups, but gene expression within the FA β-oxidation pathway and functional palmitate oxidation in the proximal ileum was significantly increased only in ω3PL-H mice. In conclusion, enhanced intestinal FA oxidation could contribute to the strong antisteatotic effects of Omega-3 when administered as phospholipids to dietary obese mice.
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Affiliation(s)
- Petra Kroupova
- Laboratory of Adipose Tissue Biology, Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 14220 Prague, Czech Republic; (P.K.); (I.I.); (M.O.); (J.K.)
| | - Evert M. van Schothorst
- Human and Animal Physiology, Wageningen University, 6708 WD Wageningen, The Netherlands; (E.M.v.S.); (J.K.); (A.B.)
| | - Jaap Keijer
- Human and Animal Physiology, Wageningen University, 6708 WD Wageningen, The Netherlands; (E.M.v.S.); (J.K.); (A.B.)
| | - Annelies Bunschoten
- Human and Animal Physiology, Wageningen University, 6708 WD Wageningen, The Netherlands; (E.M.v.S.); (J.K.); (A.B.)
| | - Martin Vodicka
- Laboratory of Epithelial Physiology, Institute of Physiology of the Czech Academy of Sciences, 14220 Prague, Czech Republic;
| | - Ilaria Irodenko
- Laboratory of Adipose Tissue Biology, Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 14220 Prague, Czech Republic; (P.K.); (I.I.); (M.O.); (J.K.)
| | - Marina Oseeva
- Laboratory of Adipose Tissue Biology, Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 14220 Prague, Czech Republic; (P.K.); (I.I.); (M.O.); (J.K.)
| | - Petr Zacek
- Proteomics Core Facility, Faculty of Science, Charles University, Division BIOCEV, 25250 Vestec, Czech Republic;
| | - Jan Kopecky
- Laboratory of Adipose Tissue Biology, Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 14220 Prague, Czech Republic; (P.K.); (I.I.); (M.O.); (J.K.)
| | - Martin Rossmeisl
- Laboratory of Adipose Tissue Biology, Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 14220 Prague, Czech Republic; (P.K.); (I.I.); (M.O.); (J.K.)
- Correspondence: (M.R.); (O.H.); Tel.: +420-296443706 (M.R. & O.H.); Fax: +420 296442599 (M.R. & O.H.)
| | - Olga Horakova
- Laboratory of Adipose Tissue Biology, Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 14220 Prague, Czech Republic; (P.K.); (I.I.); (M.O.); (J.K.)
- Correspondence: (M.R.); (O.H.); Tel.: +420-296443706 (M.R. & O.H.); Fax: +420 296442599 (M.R. & O.H.)
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10
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Dávalos-Salas M, Mariadason JM, Watt MJ, Montgomery MK. Molecular regulators of lipid metabolism in the intestine - Underestimated therapeutic targets for obesity? Biochem Pharmacol 2020; 178:114091. [PMID: 32535104 DOI: 10.1016/j.bcp.2020.114091] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 06/08/2020] [Accepted: 06/09/2020] [Indexed: 02/07/2023]
Abstract
The incidence of obesity and type 2 diabetes continues to rise across the globe necessitating the need to identify new therapeutic approaches to manage these diseases. In this review, we explore the potential for therapeutic interventions focussed on the intestinal epithelium, by targeting the role of this tissue in lipid uptake, lipid-mediated cross talk and lipid oxidation. We focus initially on ongoing strategies to manage obesity by targeting the essential role of the intestinal epithelium in lipid uptake, and in mediating tissue cross talk to regulate food intake. Subsequently, we explore a previously underestimated capacity of intestinal epithelial cells to oxidize fatty acids. In this context, we describe recent findings which have unveiled a key role for the peroxisome proliferator-activated receptor (PPAR) family of nuclear receptors and histone deacetylases (HDACs) in the regulation of lipid oxidation genes in enterocytes and how targeted genetic manipulation of these factors in enterocytes reduces weight gain, identifying intestinal PPARs and HDACs as potential therapeutic targets in the management of obesity.
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Affiliation(s)
- Mercedes Dávalos-Salas
- Olivia Newton John Cancer Research Institute, Melbourne, Victoria, Australia; La Trobe University School of Cancer Medicine, Melbourne, Victoria, Australia
| | - John M Mariadason
- Olivia Newton John Cancer Research Institute, Melbourne, Victoria, Australia; La Trobe University School of Cancer Medicine, Melbourne, Victoria, Australia
| | - Matthew J Watt
- Department of Physiology, Faculty of Medicine Dentistry and Health Sciences, University of Melbourne, Parkville, Victoria, Australia
| | - Magdalene K Montgomery
- Department of Physiology, Faculty of Medicine Dentistry and Health Sciences, University of Melbourne, Parkville, Victoria, Australia.
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Xiao C, Stahel P, Nahmias A, Lewis GF. Emerging Role of Lymphatics in the Regulation of Intestinal Lipid Mobilization. Front Physiol 2020; 10:1604. [PMID: 32063861 PMCID: PMC7000543 DOI: 10.3389/fphys.2019.01604] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Accepted: 12/20/2019] [Indexed: 12/21/2022] Open
Abstract
Intestinal handling of dietary triglycerides has important implications for health and disease. Following digestion in the intestinal lumen, absorption, and re-esterification of fatty acids and monoacylglycerols in intestinal enterocytes, triglycerides are packaged into lipoprotein particles (chylomicrons) for secretion or into cytoplasmic lipid droplets for transient or more prolonged storage. Despite the recognition of prolonged retention of triglycerides in the post-absorptive phase and subsequent release from the intestine in chylomicron particles, the underlying regulatory mechanisms remain poorly understood. Chylomicron secretion involves multiple steps, including intracellular assembly and post-assembly transport through cellular organelles, the lamina propria, and the mesenteric lymphatics before being released into the circulation. Contrary to the long-held view that the intestinal lymphatic vasculature acts mainly as a passive conduit, it is increasingly recognized to play an active and regulatory role in the rate of chylomicron release into the circulation. Here, we review the latest advances in understanding the role of lymphatics in intestinal lipid handling and chylomicron secretion. We highlight emerging evidence that oral glucose and the gut hormone glucagon-like peptide-2 mobilize retained enteral lipid by differing mechanisms to promote the secretion of chylomicrons via glucose possibly by mobilizing cytoplasmic lipid droplets and via glucagon-like peptide-2 possibly by targeting post-enterocyte secretory mechanisms. We discuss other potential regulatory factors that are the focus of ongoing and future research. Regulation of lymphatic pumping and function is emerging as an area of great interest in our understanding of the integrated absorption of dietary fat and chylomicron secretion and potential implications for whole-body metabolic health.
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Affiliation(s)
- Changting Xiao
- Department of Medicine and Department of Physiology, Banting and Best Diabetes Centre, University of Toronto, Toronto, ON, Canada
| | - Priska Stahel
- Department of Medicine and Department of Physiology, Banting and Best Diabetes Centre, University of Toronto, Toronto, ON, Canada
| | - Avital Nahmias
- Department of Medicine and Department of Physiology, Banting and Best Diabetes Centre, University of Toronto, Toronto, ON, Canada
| | - Gary F Lewis
- Department of Medicine and Department of Physiology, Banting and Best Diabetes Centre, University of Toronto, Toronto, ON, Canada
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Dávalos-Salas M, Montgomery MK, Reehorst CM, Nightingale R, Ng I, Anderton H, Al-Obaidi S, Lesmana A, Scott CM, Ioannidis P, Kalra H, Keerthikumar S, Tögel L, Rigopoulos A, Gong SJ, Williams DS, Yoganantharaja P, Bell-Anderson K, Mathivanan S, Gibert Y, Hiebert S, Scott AM, Watt MJ, Mariadason JM. Deletion of intestinal Hdac3 remodels the lipidome of enterocytes and protects mice from diet-induced obesity. Nat Commun 2019; 10:5291. [PMID: 31757939 PMCID: PMC6876593 DOI: 10.1038/s41467-019-13180-8] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Accepted: 10/23/2019] [Indexed: 12/22/2022] Open
Abstract
Histone deacetylase 3 (Hdac3) regulates the expression of lipid metabolism genes in multiple tissues, however its role in regulating lipid metabolism in the intestinal epithelium is unknown. Here we demonstrate that intestine-specific deletion of Hdac3 (Hdac3IKO) protects mice from diet induced obesity. Intestinal epithelial cells (IECs) from Hdac3IKO mice display co-ordinate induction of genes and proteins involved in mitochondrial and peroxisomal β-oxidation, have an increased rate of fatty acid oxidation, and undergo marked remodelling of their lipidome, particularly a reduction in long chain triglycerides. Many HDAC3-regulated fatty oxidation genes are transcriptional targets of the PPAR family of nuclear receptors, Hdac3 deletion enhances their induction by PPAR-agonists, and pharmacological HDAC3 inhibition induces their expression in enterocytes. These findings establish a central role for HDAC3 in co-ordinating PPAR-regulated lipid oxidation in the intestinal epithelium, and identify intestinal HDAC3 as a potential therapeutic target for preventing obesity and related diseases. Histone deacetylase 3 (HDAC3) is a regulator of lipid homeostasis in several tissues, however, its role in intestinal lipid metabolism was not yet known. Here the authors study intestine specific HDAC3 knock out mice and report that these animals have increased fatty acid oxidation and undergo remodeling of the intestinal epithelial cell lipidome.
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Affiliation(s)
- Mercedes Dávalos-Salas
- Olivia Newton John Cancer Research Institute, Melbourne, Victoria, Australia.,La Trobe University School of Cancer Medicine, Melbourne, Victoria, Australia
| | - Magdalene K Montgomery
- Department of Physiology, Faculty of Medicine Dentistry and Health Sciences, University of Melbourne, Parkville, Victoria, Australia
| | - Camilla M Reehorst
- Olivia Newton John Cancer Research Institute, Melbourne, Victoria, Australia.,La Trobe University School of Cancer Medicine, Melbourne, Victoria, Australia
| | - Rebecca Nightingale
- Olivia Newton John Cancer Research Institute, Melbourne, Victoria, Australia.,La Trobe University School of Cancer Medicine, Melbourne, Victoria, Australia
| | - Irvin Ng
- Olivia Newton John Cancer Research Institute, Melbourne, Victoria, Australia.,La Trobe University School of Cancer Medicine, Melbourne, Victoria, Australia
| | - Holly Anderton
- Olivia Newton John Cancer Research Institute, Melbourne, Victoria, Australia
| | - Sheren Al-Obaidi
- Olivia Newton John Cancer Research Institute, Melbourne, Victoria, Australia
| | - Analia Lesmana
- Olivia Newton John Cancer Research Institute, Melbourne, Victoria, Australia
| | - Cameron M Scott
- Olivia Newton John Cancer Research Institute, Melbourne, Victoria, Australia
| | - Paul Ioannidis
- Olivia Newton John Cancer Research Institute, Melbourne, Victoria, Australia
| | - Hina Kalra
- La Trobe Institute for Molecular Sciences, La Trobe University, Melbourne, Victoria, Australia
| | - Shivakumar Keerthikumar
- La Trobe Institute for Molecular Sciences, La Trobe University, Melbourne, Victoria, Australia
| | - Lars Tögel
- Olivia Newton John Cancer Research Institute, Melbourne, Victoria, Australia.,La Trobe University School of Cancer Medicine, Melbourne, Victoria, Australia
| | - Angela Rigopoulos
- Olivia Newton John Cancer Research Institute, Melbourne, Victoria, Australia.,La Trobe University School of Cancer Medicine, Melbourne, Victoria, Australia
| | - Sylvia J Gong
- Olivia Newton John Cancer Research Institute, Melbourne, Victoria, Australia
| | - David S Williams
- Olivia Newton John Cancer Research Institute, Melbourne, Victoria, Australia.,La Trobe University School of Cancer Medicine, Melbourne, Victoria, Australia.,Department of Pathology, Austin Health, Melbourne, Victoria, Australia
| | | | - Kim Bell-Anderson
- Faculty of Science, Charles Perkins Centre, University of Sydney, Sydney, NSW, Australia
| | - Suresh Mathivanan
- La Trobe Institute for Molecular Sciences, La Trobe University, Melbourne, Victoria, Australia
| | - Yann Gibert
- Department of Medicine, Deakin University, Geelong, Victoria, Australia
| | | | - Andrew M Scott
- Olivia Newton John Cancer Research Institute, Melbourne, Victoria, Australia.,La Trobe University School of Cancer Medicine, Melbourne, Victoria, Australia.,Department of Medicine, University of Melbourne, Melbourne, Victoria, Australia
| | - Matthew J Watt
- Department of Physiology, Faculty of Medicine Dentistry and Health Sciences, University of Melbourne, Parkville, Victoria, Australia.
| | - John M Mariadason
- Olivia Newton John Cancer Research Institute, Melbourne, Victoria, Australia. .,La Trobe University School of Cancer Medicine, Melbourne, Victoria, Australia. .,Department of Medicine, University of Melbourne, Melbourne, Victoria, Australia.
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Langhans W. Serendipity and spontaneity - Critical components in 40 years of academia. Physiol Behav 2019; 204:76-85. [PMID: 30753847 DOI: 10.1016/j.physbeh.2019.02.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Accepted: 02/08/2019] [Indexed: 10/27/2022]
Abstract
I was flattered and felt tremendously honored to receive the 2018 Distinguished Career Award (DCA) from SSIB, the society that I always considered my scientific home, my family. Preparing the award lecture, I reflected about defining features of my career. This paper summarizes this very personal retrospective. As you will read, serendipity and more or less spontaneous decisions; i.e., some luck to be in the right place at the right time, and spontaneity to grab an opportunity when it presented itself, played a major role, and not necessarily a thorough analysis of my life situation at various junctions of my career path. Luck also often had the name of a fantastic tutor or mentor, or came in the form of enlightening discussions with a friend. Science is teamwork, which emphasizes how important collaborators, post-docs, students and technicians are. Although deep thinking was not necessarily crucial for my career path, a thorough examination is of course necessary when analyzing data, which were often most important when they did not confirm my hypothesis. Science is also hard work considering how much time one spends, but it never seemed like work to me because I had always this desire to find out how things in the organism work, and I always felt privileged to be able to pursue my "hobby" and even get a decent pay for it. In short, being a scientist is probably one of the most rewarding professional activities that life can offer.
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Affiliation(s)
- Wolfgang Langhans
- Physiology and Behavior Laboratory, Department of Health Sciences and Technology, ETH Zurich, Schorenstr. 16, 8603 Schwerzenbach, Switzerland.
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Kaufman S, Arnold M, Diaz AA, Neubauer H, Wolfrum S, Köfeler H, Langhans W, Krieger JP. Roux-en-Y gastric bypass surgery reprograms enterocyte triglyceride metabolism and postprandial secretion in rats. Mol Metab 2019; 23:51-59. [PMID: 30905616 PMCID: PMC6480308 DOI: 10.1016/j.molmet.2019.03.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Revised: 03/03/2019] [Accepted: 03/07/2019] [Indexed: 12/25/2022] Open
Abstract
OBJECTIVE Roux-en-Y gastric bypass (RYGB) surgery produces rapid and persistent reductions in plasma triglyceride (TG) levels associated with fewer cardiovascular events. The mechanisms of the reduction in systemic TG levels remain unclear. We hypothesized that RYGB reduces intestinal TG secretion via altered enterocyte lipid handling. METHODS RYGB or Sham surgery was performed in diet-induced obese, insulin-resistant male Sprague-Dawley rats. First, we tested whether RYGB reduced test meal-induced TG levels in the intestinal lymph, a direct readout of enterocyte lipid secretion. Second, we examined whether RYGB modified TG enterocyte secretion at the single lipid level and in comparison to other lipid subclasses, applying mass spectrometry lipidomics to the intestinal lymph of RYGB and Sham rats (0-21 days after surgery). Third, we explored whether RYGB modulated the metabolic characteristics of primary enterocytes using transcriptional and functional assays relevant to TG absorption, reesterification, storage in lipid droplets, and oxidation. RESULTS RYGB reduced overall postprandial TG concentrations compared to Sham surgery in plasma and intestinal lymph similarly. RYGB reduced lymphatic TG concentrations more than other lipid subclasses, and shifted the remaining TG pool towards long-chain, unsaturated species. In enterocytes of fasted RYGB rats, lipid uptake was transcriptionally (Fatp4, Fabp2, Cd36) and functionally reduced compared to Sham, whereas TG reesterification genes were upregulated. CONCLUSION Our results show that RYGB substantially reduces intestinal TG secretion and modifies enterocyte lipid absorption and handling in rats. These changes likely contribute to the improvements in the plasma TG profile observed after RYGB in humans.
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Affiliation(s)
- Sharon Kaufman
- Physiology and Behavior Laboratory, ETH Zurich, Schwerzenbach, Switzerland.
| | - Myrtha Arnold
- Physiology and Behavior Laboratory, ETH Zurich, Schwerzenbach, Switzerland
| | | | - Heike Neubauer
- Department of Cardiometabolic Diseases Research, Boehringer Ingelheim Pharma GmbH and Co. KG, 88397 Biberach/Riss, Germany
| | - Susanne Wolfrum
- Laboratory of Organic Chemistry, ETH Zurich, Zurich, Switzerland
| | - Harald Köfeler
- Core Facility Mass Spectrometry Lipidomics Research Center Graz, Austria
| | - Wolfgang Langhans
- Physiology and Behavior Laboratory, ETH Zurich, Schwerzenbach, Switzerland
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