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Khouri H, Roberge M, Ussher JR, Aguer C. Acetoacetate and d- and l-β-hydroxybutyrate have distinct effects on basal and insulin-stimulated glucose uptake in L6 skeletal muscle cells. Am J Physiol Cell Physiol 2024; 326:C1710-C1720. [PMID: 38708524 DOI: 10.1152/ajpcell.00718.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2023] [Revised: 04/02/2024] [Accepted: 04/25/2024] [Indexed: 05/07/2024]
Abstract
Ketone bodies (acetoacetate and β-hydroxybutyrate) are oxidized in skeletal muscle mainly during fasting as an alternative source of energy to glucose. Previous studies suggest that there is a negative relationship between increased muscle ketolysis and muscle glucose metabolism in mice with obesity and/or type 2 diabetes. Therefore, we investigated the connection between increased ketone body exposure and muscle glucose metabolism by measuring the effect of a 3-h exposure to ketone bodies on glucose uptake in differentiated L6 myotubes. We showed that exposure to acetoacetate at a typical concentration (0.2 mM) resulted in increased basal glucose uptake in L6 myotubes, which was dependent on increased membrane glucose transporter type 4 (GLUT4) translocation. Basal and insulin-stimulated glucose uptake was also increased with a concentration of acetoacetate reflective of diabetic ketoacidosis or a ketogenic diet (1 mM). We found that β-hydroxybutyrate had a variable effect on basal glucose uptake: a racemic mixture of the two β-hydroxybutyrate enantiomers (d and l) appeared to decrease basal glucose uptake, while 3 mM d-β-hydroxybutyrate alone increased basal glucose uptake. However, the effects of the ketone bodies individually were not observed when acetoacetate was present in combination with β-hydroxybutyrate. These results provide insight that will help elucidate the effect of ketone bodies in the context of specific metabolic diseases and nutritional states (e.g., type 2 diabetes and ketogenic diets).NEW & NOTEWORTHY A limited number of studies investigate the effect of ketone bodies at concentrations reflective of both typical fasting and ketoacidosis. We tested a mix of physiologically relevant concentrations of ketone bodies, which allowed us to highlight the differential effects of d- and l-β-hydroxybutyrate and acetoacetate on skeletal muscle cell glucose uptake. Our findings will assist in better understanding the mechanisms that contribute to muscle insulin resistance and provide guidance on recommendations regarding ketogenic diets.
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Affiliation(s)
- Hannah Khouri
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
- Institut du Savoir Montfort - recherche, Ottawa, Ontario, Canada
| | - Mathilde Roberge
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
- Institut du Savoir Montfort - recherche, Ottawa, Ontario, Canada
| | - John R Ussher
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Alberta, Canada
- Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Céline Aguer
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
- Institut du Savoir Montfort - recherche, Ottawa, Ontario, Canada
- Department of Physiology, Faculty of Medicine and Health Sciences, McGill University - Campus Outaouais, Gatineau, Quebec, Canada
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2
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Moore MP, Shryack G, Alessi I, Wieschhaus N, Meers GM, Johnson SA, Wheeler AA, Ibdah JA, Parks EJ, Rector RS. Relationship between serum β-hydroxybutyrate and hepatic fatty acid oxidation in individuals with obesity and NAFLD. Am J Physiol Endocrinol Metab 2024; 326:E493-E502. [PMID: 38381399 PMCID: PMC11194052 DOI: 10.1152/ajpendo.00336.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Revised: 02/15/2024] [Accepted: 02/16/2024] [Indexed: 02/22/2024]
Abstract
Nonalcoholic fatty liver disease (NAFLD) is characterized by excess lipid accumulation that can progress to inflammation (nonalcoholic steatohepatitis, NASH), and fibrosis. Serum β-hydroxybutyrate (β-HB), a product of the ketogenic pathway, is commonly used as a surrogate marker for hepatic fatty acid oxidation (FAO). However, it remains uncertain whether this relationship holds true in the context of NAFLD in humans. We compared fasting serum β-HB levels with direct measurement of liver mitochondrial palmitate oxidation in humans stratified based on NAFLD severity (n = 142). Patients were stratified based on NAFLD activity score (NAS): NAS = 0 (no disease), NAS = 1-2 (mild), NAS = 3-4 (moderate), and NAS ≥ 5 (advanced). Moderate and advanced NAFLD is associated with reductions in liver 3-hydroxy-3-methylglutaryl-CoA synthase 2 (HMGCS2), serum β-HB, but not 3-hydroxy-3-methylglutaryl-CoA lyase (HMGCL) mRNA, relative to no disease. Worsening liver mitochondrial complete palmitate oxidation corresponded with lower HMGCS2 mRNA but not total (complete + incomplete) palmitate oxidation. Interestingly, we found that liver HMGCS2 mRNA and serum β-HB correlated with liver mitochondrial β-hydroxyacyl-CoA dehydrogenase (β-HAD) activity and CPT1A mRNA. Also, lower mitochondrial mass and markers of mitochondrial turnover positively correlated with lower HMGCS2 in the liver. These data suggest that liver ketogenesis and FAO occur at comparable rates in individuals with NAFLD. Our findings support the utility of serum β-HB to serve as a marker of liver injury and hepatic FAO in the context of NAFLD.NEW & NOTEWORTHY Serum β-hydroxybutyrate (β-HB) is frequently utilized as a surrogate marker for hepatic fatty acid oxidation; however, few studies have investigated this relationship during states of liver disease. We found that the progression of nonalcoholic fatty liver disease (NAFLD) is associated with reductions in circulating β-HB and liver 3-hydroxy-3-methylglutaryl-CoA synthase 2 (HMGCS2). As well, decreased rates of hepatic fatty acid oxidation correlated with liver HMGCS2 mRNA and serum β-HB. Our work supports serum β-HB as a potential marker for hepatic fatty acid oxidation and liver injury during NAFLD.
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Affiliation(s)
- Mary P Moore
- Research Service, Harry S Truman Memorial Veterans Medical Center, Columbia, Missouri, United States
- Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, Missouri, United States
| | - Grace Shryack
- Research Service, Harry S Truman Memorial Veterans Medical Center, Columbia, Missouri, United States
- Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, Missouri, United States
- NextGen Precision Health, Columbia, Missouri, United States
| | - Isabella Alessi
- Research Service, Harry S Truman Memorial Veterans Medical Center, Columbia, Missouri, United States
- Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, Missouri, United States
- NextGen Precision Health, Columbia, Missouri, United States
| | - Nicole Wieschhaus
- Research Service, Harry S Truman Memorial Veterans Medical Center, Columbia, Missouri, United States
- Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, Missouri, United States
- NextGen Precision Health, Columbia, Missouri, United States
| | - Grace M Meers
- Research Service, Harry S Truman Memorial Veterans Medical Center, Columbia, Missouri, United States
- Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, Missouri, United States
- NextGen Precision Health, Columbia, Missouri, United States
| | - Sarah A Johnson
- Research Service, Harry S Truman Memorial Veterans Medical Center, Columbia, Missouri, United States
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Missouri, Columbia, Missouri, United States
| | - Andrew A Wheeler
- Department of Surgery, University of Missouri, Columbia, Missouri, United States
| | - Jamal A Ibdah
- Research Service, Harry S Truman Memorial Veterans Medical Center, Columbia, Missouri, United States
- Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, Missouri, United States
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Missouri, Columbia, Missouri, United States
| | - Elizabeth J Parks
- Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, Missouri, United States
- NextGen Precision Health, Columbia, Missouri, United States
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Missouri, Columbia, Missouri, United States
| | - R Scott Rector
- Research Service, Harry S Truman Memorial Veterans Medical Center, Columbia, Missouri, United States
- Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, Missouri, United States
- NextGen Precision Health, Columbia, Missouri, United States
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Missouri, Columbia, Missouri, United States
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3
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Henin G, Loumaye A, Leclercq IA, Lanthier N. Myosteatosis: Diagnosis, pathophysiology and consequences in metabolic dysfunction-associated steatotic liver disease. JHEP Rep 2024; 6:100963. [PMID: 38322420 PMCID: PMC10844870 DOI: 10.1016/j.jhepr.2023.100963] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Revised: 10/27/2023] [Accepted: 10/27/2023] [Indexed: 02/08/2024] Open
Abstract
Metabolic dysfunction-associated steatotic liver disease (MASLD) is associated with an increased risk of multisystemic complications, including muscle changes such as sarcopenia and myosteatosis that can reciprocally affect liver function. We conducted a systematic review to highlight innovative assessment tools, pathophysiological mechanisms and metabolic consequences related to myosteatosis in MASLD, based on original articles screened from PUBMED, EMBASE and COCHRANE databases. Forty-six original manuscripts (14 pre-clinical and 32 clinical studies) were included. Microscopy (8/14) and tissue lipid extraction (8/14) are the two main assessment techniques used to measure muscle lipid content in pre-clinical studies. In clinical studies, imaging is the most used assessment tool and included CT (14/32), MRI (12/32) and ultrasound (4/32). Assessed muscles varied across studies but mainly included paravertebral (4/14 in pre-clinical; 13/32 in clinical studies) and lower limb muscles (10/14 in preclinical; 13/32 in clinical studies). Myosteatosis is already highly prevalent in non-cirrhotic stages of MASLD and correlates with disease activity when using muscle density assessed by CT. Numerous pathophysiological mechanisms were found and included: high-fat and high-fructose diet, dysregulation in fatty acid transport and ketogenesis, endocrine disorders and impaired microRNA122 pathway signalling. In this review we also uncover several potential consequences of myosteatosis in MASLD, such as insulin resistance, MASLD progression from steatosis to metabolic steatohepatitis and loss of muscle strength. In conclusion, data on myosteatosis in MASLD are already available. Screening for myosteatosis could be highly relevant in the context of MASLD, considering its correlation with MASLD activity as well as its related consequences.
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Affiliation(s)
- Guillaume Henin
- Service d’Hépato-Gastroentérologie, Cliniques universitaires Saint-Luc, UCLouvain, Brussels, Belgium
- Laboratory of Hepatogastroenterology, Institut de Recherche Expérimentale et Clinique, Université catholique de Louvain (UCLouvain), Brussels, Belgium
| | - Audrey Loumaye
- Service d’Endocrinologie, Diabétologie et Nutrition, Cliniques universitaires Saint-Luc, UCLouvain, Brussels, Belgium
| | - Isabelle A. Leclercq
- Laboratory of Hepatogastroenterology, Institut de Recherche Expérimentale et Clinique, Université catholique de Louvain (UCLouvain), Brussels, Belgium
| | - Nicolas Lanthier
- Service d’Hépato-Gastroentérologie, Cliniques universitaires Saint-Luc, UCLouvain, Brussels, Belgium
- Laboratory of Hepatogastroenterology, Institut de Recherche Expérimentale et Clinique, Université catholique de Louvain (UCLouvain), Brussels, Belgium
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4
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Mey JT, Vandagmansar B, Dantas WS, Belmont KP, Axelrod CL, Kirwan JP. Ketogenic propensity is differentially related to lipid-induced hepatic and peripheral insulin resistance. Acta Physiol (Oxf) 2023; 239:e14054. [PMID: 37840478 DOI: 10.1111/apha.14054] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 09/11/2023] [Accepted: 09/26/2023] [Indexed: 10/17/2023]
Abstract
AIM Determine the ketogenic response (β-hydroxybutyrate, a surrogate of hepatic ketogenesis) to a controlled lipid overload in humans. METHODS In total, nineteen young, healthy adults (age: 28.4 ± 1.7 years; BMI: 22.7 ± 0.3 kg/m2 ) received either a 12 h overnight lipid infusion or saline in a randomized, crossover design. Plasma ketones and inflammatory markers were quantified by colorimetric and multiplex assays. Hepatic and peripheral insulin sensitivity was assessed by the hyperinsulinemic-euglycemic clamp. Skeletal muscle biopsies were obtained to quantify gene expression related to ketone body metabolism and inflammation. RESULTS By design, the lipid overload-induced hepatic (50%, p < 0.001) and peripheral insulin resistance (73%, p < 0.01) in healthy adults. Ketones increased with hyperlipidemia and were subsequently reduced with hyperinsulinemia during the clamp procedure (Saline: Basal = 0.22 mM, Insulin = 0.07 mM; Lipid: Basal = 0.78 mM, Insulin = 0.51 mM; 2-way ANOVA: Lipid p < 0.001, Insulin p < 0.001, Interaction p = 0.07). In the saline control condition, ketones did not correlate with hepatic or peripheral insulin sensitivity. Conversely, in the lipid condition, ketones were positively correlated with hepatic insulin sensitivity (r = 0.59, p < 0.01), but inversely related to peripheral insulin sensitivity (r = -0.64, p < 0.01). Hyperlipidemia increased plasma inflammatory markers, but did not impact skeletal muscle inflammatory gene expression. Gene expression related to ketone and fatty acid metabolism in skeletal muscle increased in response to hyperlipidemia. CONCLUSION This work provides important insight into the role of ketones in human health and suggests that ketone body metabolism is altered at the onset of lipid-induced insulin resistance.
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Affiliation(s)
- J T Mey
- Pennington Biomedical Research Center, Baton Rouge, Louisiana, USA
| | - B Vandagmansar
- Pennington Biomedical Research Center, Baton Rouge, Louisiana, USA
| | - W S Dantas
- Pennington Biomedical Research Center, Baton Rouge, Louisiana, USA
| | - K P Belmont
- Pennington Biomedical Research Center, Baton Rouge, Louisiana, USA
| | - C L Axelrod
- Pennington Biomedical Research Center, Baton Rouge, Louisiana, USA
| | - J P Kirwan
- Pennington Biomedical Research Center, Baton Rouge, Louisiana, USA
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5
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Di Cesare F, Calgaro M, Ghini V, Squarzanti DF, De Prisco A, Visciglia A, Zanetta P, Rolla R, Savoia P, Amoruso A, Azzimonti B, Vitulo N, Tenori L, Luchinat C, Pane M. Exploring the Effects of Probiotic Treatment on Urinary and Serum Metabolic Profiles in Healthy Individuals. J Proteome Res 2023; 22:3866-3878. [PMID: 37970754 PMCID: PMC10696601 DOI: 10.1021/acs.jproteome.3c00548] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 10/11/2023] [Accepted: 10/24/2023] [Indexed: 11/17/2023]
Abstract
Probiotics are live microorganisms that confer health benefits when administered in adequate amounts. They are used to promote gut health and alleviate various disorders. Recently, there has been an increasing interest in the potential effects of probiotics on human physiology. In the presented study, the effects of probiotic treatment on the metabolic profiles of human urine and serum using a nuclear magnetic resonance (NMR)-based metabonomic approach were investigated. Twenty-one healthy volunteers were enrolled in the study, and they received two different dosages of probiotics for 8 weeks. During the study, urine and serum samples were collected from volunteers before and during probiotic supplementation. The results showed that probiotics had a significant impact on the urinary and serum metabolic profiles without altering their phenotypes. This study demonstrated the effects of probiotics in terms of variations of metabolite levels resulting also from the different probiotic posology. Overall, the results suggest that probiotic administration may affect both urine and serum metabolomes, although more research is needed to understand the mechanisms and clinical implications of these effects. NMR-based metabonomic analysis of biofluids is a powerful tool for monitoring host-gut microflora dynamic interaction as well as for assessing the individual response to probiotic treatment.
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Affiliation(s)
- Francesca Di Cesare
- Magnetic
Resonance Center (CERM), University of Florence, Via Luigi Sacconi 6, Sesto Fiorentino, Firenze 50019, Italy
- Department
of Chemistry “Ugo Schiff”, University of Florence, Via della Lastruccia 3, Sesto Fiorentino 50019, Italy
| | - Matteo Calgaro
- Department
of Biotechnology, University of Verona, Strada le Grazie, 15, Verona 37134, Italy
| | - Veronica Ghini
- Magnetic
Resonance Center (CERM), University of Florence, Via Luigi Sacconi 6, Sesto Fiorentino, Firenze 50019, Italy
- Department
of Chemistry “Ugo Schiff”, University of Florence, Via della Lastruccia 3, Sesto Fiorentino 50019, Italy
| | - Diletta Francesca Squarzanti
- Department
of Health Sciences (DiSS), University of
Piemonte Orientale (UPO), Via Solaroli, 17, Novara 28100, Italy
- Center
for Translational Research on Autoimmune and Allergic Diseases (CAAD),
Department of Health Sciences (DiSS), University
of Piemonte Orientale (UPO), Corso Trieste, 15, Novara 28100, Italy
| | | | | | - Paola Zanetta
- Department
of Health Sciences (DiSS), University of
Piemonte Orientale (UPO), Via Solaroli, 17, Novara 28100, Italy
- Center
for Translational Research on Autoimmune and Allergic Diseases (CAAD),
Department of Health Sciences (DiSS), University
of Piemonte Orientale (UPO), Corso Trieste, 15, Novara 28100, Italy
| | - Roberta Rolla
- Department
of Health Sciences (DiSS), University of
Piemonte Orientale (UPO), Via Solaroli, 17, Novara 28100, Italy
| | - Paola Savoia
- Department
of Health Sciences (DiSS), University of
Piemonte Orientale (UPO), Via Solaroli, 17, Novara 28100, Italy
| | - Angela Amoruso
- Probiotical
Research Srl, Via Enrico
Mattei, 3, Novara 28100, Italy
| | - Barbara Azzimonti
- Department
of Health Sciences (DiSS), University of
Piemonte Orientale (UPO), Via Solaroli, 17, Novara 28100, Italy
- Center
for Translational Research on Autoimmune and Allergic Diseases (CAAD),
Department of Health Sciences (DiSS), University
of Piemonte Orientale (UPO), Corso Trieste, 15, Novara 28100, Italy
| | - Nicola Vitulo
- Department
of Biotechnology, University of Verona, Strada le Grazie, 15, Verona 37134, Italy
| | - Leonardo Tenori
- Magnetic
Resonance Center (CERM), University of Florence, Via Luigi Sacconi 6, Sesto Fiorentino, Firenze 50019, Italy
- Department
of Chemistry “Ugo Schiff”, University of Florence, Via della Lastruccia 3, Sesto Fiorentino 50019, Italy
- Consorzio
Interuniversitario Risonanze Magnetiche MetalloProteine (CIRMMP), Via Luigi Sacconi 6, Sesto Fiorentino, Firenze 50019, Italy
| | - Claudio Luchinat
- Consorzio
Interuniversitario Risonanze Magnetiche MetalloProteine (CIRMMP), Via Luigi Sacconi 6, Sesto Fiorentino, Firenze 50019, Italy
- Giotto
Biotech S.r.l., Via Madonna
del Piano, 6, Sesto Fiorentino, Firenze 50019, Italy
| | - Marco Pane
- Probiotical
Research Srl, Via Enrico
Mattei, 3, Novara 28100, Italy
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6
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Lundsgaard AM, Bojsen-Møller KN, Kiens B. Dietary Regulation of Hepatic Triacylglycerol Content-the Role of Eucaloric Carbohydrate Restriction with Fat or Protein Replacement. Adv Nutr 2023; 14:1359-1373. [PMID: 37591342 PMCID: PMC10721463 DOI: 10.1016/j.advnut.2023.08.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 07/21/2023] [Accepted: 08/07/2023] [Indexed: 08/19/2023] Open
Abstract
Accumulation of hepatic triacylglycerol (TG) is highly associated with impaired whole-body insulin-glucose homeostasis and dyslipidemia. The summarized findings from human intervention studies investigating the effect of reduced dietary carbohydrate and increased fat intake (and in studies also increased protein) while maintaining energy intake at eucaloric requirements reveal a beneficial effect of carbohydrate reduction on hepatic TG content in obese individuals with steatosis and indices of insulin resistance. Evidence suggests that the reduction of hepatic TG content after reduced intake of carbohydrates and increased fat/protein intake in humans, results from regulation of fatty acid (FA) metabolism within the liver, with an increase in hepatic FA oxidation and ketogenesis, together with a concomitant downregulation of FA synthesis from de novo lipogenesis. The adaptations in hepatic metabolism may result from reduced intrahepatic monosaccharide and insulin availability, reduced glycolysis and increased FA availability when carbohydrate intake is reduced.
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Affiliation(s)
- Anne-Marie Lundsgaard
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark.
| | | | - Bente Kiens
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
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7
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Bae J, Lee BW. Association between Impaired Ketogenesis and Metabolic-Associated Fatty Liver Disease. Biomolecules 2023; 13:1506. [PMID: 37892188 PMCID: PMC10604525 DOI: 10.3390/biom13101506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 09/26/2023] [Accepted: 10/06/2023] [Indexed: 10/29/2023] Open
Abstract
Metabolic (dysfunction) associated fatty liver disease (MAFLD) is generally developed with excessive accumulation of lipids in the liver. Ketogenesis is an efficient pathway for the disposal of fatty acids in the liver and its metabolic benefits have been reported. In this review, we examined previous studies on the association between ketogenesis and MAFLD and reviewed the candidate mechanisms that can explain this association.
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Affiliation(s)
- Jaehyun Bae
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Catholic Kwandong University College of Medicine, International St. Mary’s Hospital, Incheon 22711, Republic of Korea
| | - Byung-Wan Lee
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Yonsei University College of Medicine, Seoul 03722, Republic of Korea
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8
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Li K, Wang WH, Wu JB, Xiao WH. β-hydroxybutyrate: A crucial therapeutic target for diverse liver diseases. Biomed Pharmacother 2023; 165:115191. [PMID: 37487440 DOI: 10.1016/j.biopha.2023.115191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Revised: 07/13/2023] [Accepted: 07/18/2023] [Indexed: 07/26/2023] Open
Abstract
β-hydroxybutyrate (β-HB), the most abundant ketone body, is produced primarily in the liver and acts as a substitute energy fuel to provide energy to extrahepatic tissues in the event of hypoglycemia or glycogen depletion. We now have an improved understanding of β-HB as a signal molecule and epigenetic regulatory factor as a result of intensive research over the last ten years. Because β-HB regulates various physiological and pathological processes, it may have a potential role in the treatment of metabolic diseases. The liver is the most significant metabolic organ, and the part that β-HB plays in liver disorders is receiving increasing attention. In this review, we summarize the therapeutic effects of β-HB on liver diseases and its underlying mechanisms of action. Moreover, we explore the prospects of exogenous supplements and endogenous ketosis including fasting, caloric restriction (CR), ketogenic diet (KD), and exercise as adjuvant nutritional therapies to protect the liver from damage and provide insights and strategies for exploring the treatment of various liver diseases.
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Affiliation(s)
- Ke Li
- Key Lab of Exercise and Health Sciences of Ministry of Education, Shanghai University of Sport, Shanghai 200438, China; Shanghai Key Lab of Human Performance, Shanghai University of Sport, Shanghai 200438, China
| | - Wen-Hong Wang
- Key Lab of Exercise and Health Sciences of Ministry of Education, Shanghai University of Sport, Shanghai 200438, China; Shanghai Key Lab of Human Performance, Shanghai University of Sport, Shanghai 200438, China
| | - Jia-Bin Wu
- Key Lab of Exercise and Health Sciences of Ministry of Education, Shanghai University of Sport, Shanghai 200438, China; Shanghai Key Lab of Human Performance, Shanghai University of Sport, Shanghai 200438, China
| | - Wei-Hua Xiao
- Key Lab of Exercise and Health Sciences of Ministry of Education, Shanghai University of Sport, Shanghai 200438, China; Shanghai Key Lab of Human Performance, Shanghai University of Sport, Shanghai 200438, China.
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9
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Badmus OO, Hinds TD, Stec DE. Mechanisms Linking Metabolic-Associated Fatty Liver Disease (MAFLD) to Cardiovascular Disease. Curr Hypertens Rep 2023; 25:151-162. [PMID: 37191842 PMCID: PMC10839567 DOI: 10.1007/s11906-023-01242-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/17/2023] [Indexed: 05/17/2023]
Abstract
PURPOSE OF REVIEW Metabolic-associated fatty liver disease (MAFLD) is a condition of fat accumulation in the liver that occurs in the majority of patients in combination with metabolic dysfunction in the form of overweight or obesity. In this review, we highlight the cardiovascular complications in MAFLD patients as well as some potential mechanisms linking MAFLD to the development of cardiovascular disease and highlight potential therapeutic approaches to treating cardiovascular diseases in patients with MAFLD. RECENT FINDINGS MAFLD is associated with an increased risk of cardiovascular diseases (CVD), including hypertension, atherosclerosis, cardiomyopathies, and chronic kidney disease. While clinical data have demonstrated the link between MAFLD and the increased risk of CVD development, the mechanisms responsible for this increased risk remain unknown. MAFLD can contribute to CVD through several mechanisms including its association with obesity and diabetes, increased levels of inflammation, and oxidative stress, as well as alterations in hepatic metabolites and hepatokines. Therapies to potentially treat MAFLD-induced include statins and lipid-lowering drugs, glucose-lowering agents, antihypertensive drugs, and antioxidant therapy.
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Affiliation(s)
- Olufunto O Badmus
- Department of Physiology & Biophysics, Cardiorenal, and Metabolic Diseases Research Center, University of Mississippi Medical Center, Jackson, MS, 39216, USA
| | - Terry D Hinds
- Department of Pharmacology and Nutritional Sciences, Barnstable Brown Diabetes Center, Markey Cancer Center, University of Kentucky, Lexington, KY, 40508, USA
| | - David E Stec
- Department of Physiology & Biophysics, Cardiorenal, and Metabolic Diseases Research Center, University of Mississippi Medical Center, Jackson, MS, 39216, USA.
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10
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Henderson LR, van den Berg M, Shaw DM. The effect of a 2 week ketogenic diet, versus a carbohydrate-based diet, on cognitive performance, mood and subjective sleepiness during 36 h of extended wakefulness in military personnel: An exploratory study. J Sleep Res 2023:e13832. [PMID: 36734405 DOI: 10.1111/jsr.13832] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2022] [Revised: 12/20/2022] [Accepted: 01/04/2023] [Indexed: 02/04/2023]
Abstract
Extended wakefulness, or sleep deprivation, impairs cognitive performance and brain glucose metabolism. A ketogenic diet (KD) provides an alternative fuel source, ketone bodies, that could elicit a metabolic benefit during sleep deprivation. A randomised, cross-over trial was conducted with seven male military personnel. Participants ingested an iso-energetic ketogenic diet or carbohydrate-based diet for 14 days, immediately followed by 36 h of extended wakefulness and separated by a 12 day washout. Cognitive performance, mood, subjective sleepiness, capillary blood glucose, and D-β-hydroxybutyrate concentrations were measured every 2 h during extended wakefulness. Linear mixed models were used to analyse data. D-β-hydroxybutyrate was higher (p < 0.001) and glucose was lower (p < 0.01) on the KD compared with the carbohydrate-based diet. The KD improved psychomotor vigilance task performance (number of lapses, mean reciprocal response time, mean fastest 10% response time (RT), and mean slowest 10% RT; all p < 0.05), running memory continuous performance test performance (RT and number of correct responses per minute; both p < 0.01), and vigour, fatigue, and sleepiness (all, p ≤ 0.001) compared with the carbohydrate-based diet. In conclusion, a KD demonstrated beneficial effects on cognitive performance, mood, and sleepiness during 36 h of extended wakefulness compared with a carbohydrate-based diet.
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Affiliation(s)
- Lydia Rose Henderson
- School of Sport, Exercise and Nutrition, Massey University, Auckland, New Zealand
| | - Margo van den Berg
- Sleep/Wake Research Centre, School of Health Sciences, Massey University, Wellington, New Zealand
| | - David M Shaw
- School of Sport, Exercise and Nutrition, Massey University, Auckland, New Zealand.,Aviation Medicine Unit, Royal New Zealand Air Force Base Auckland, Auckland, New Zealand
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Ezpeleta M, Gabel K, Cienfuegos S, Kalam F, Lin S, Pavlou V, Song Z, Haus JM, Koppe S, Alexandria SJ, Tussing-Humphreys L, Varady KA. Effect of alternate day fasting combined with aerobic exercise on non-alcoholic fatty liver disease: A randomized controlled trial. Cell Metab 2023; 35:56-70.e3. [PMID: 36549296 PMCID: PMC9812925 DOI: 10.1016/j.cmet.2022.12.001] [Citation(s) in RCA: 51] [Impact Index Per Article: 51.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2022] [Revised: 09/20/2022] [Accepted: 11/30/2022] [Indexed: 12/24/2022]
Abstract
Innovative non-pharmacological lifestyle strategies to treat non-alcoholic fatty liver disease (NAFLD) are critically needed. This study compared the effects of alternate day fasting (ADF) combined with exercise to fasting alone, or exercise alone, on intrahepatic triglyceride (IHTG) content. Adults with obesity and NAFLD (n = 80, 81% female, age: 23-65 years) were randomized to 1 of 4 groups for 3 months: combination of ADF (600 kcal/2,500 kJ "fast day" alternated with an ad libitum intake "feast day") and moderate-intensity aerobic exercise (5 session per week, 60 min/session); ADF alone; exercise alone; or a no-intervention control group. By month 3, IHTG content was significantly reduced in the combination group (-5.48%; 95% CI, -7.77% to -3.18%), compared with the exercise group (-1.30%; 95% CI, -3.80% to 1.20%; p = 0.02) and the control group (-0.17%; 95% CI, -2.17% to 1.83%; p < 0.01) but was not significantly different versus the ADF group (-2.25%; 95% CI, -4.46% to -0.04%; p = 0.05). Body weight, fat mass, waist circumference, and alanine transaminase (ALT) levels significantly decreased, while insulin sensitivity significantly increased in the combination group compared with the control group. Lean mass, aspartate transaminase (AST), HbA1c, blood pressure, plasma lipids, liver fibrosis score, and hepatokines (fetuin-A, FGF-21, and selenoprotein P) did not differ between groups. Combining intermittent fasting with exercise is effective for reducing hepatic steatosis in patients with NAFLD but may offer no additional benefit versus fasting alone.
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Affiliation(s)
- Mark Ezpeleta
- Department of Kinesiology and Nutrition, University of Illinois at Chicago, Chicago, IL, USA
| | - Kelsey Gabel
- Department of Kinesiology and Nutrition, University of Illinois at Chicago, Chicago, IL, USA
| | - Sofia Cienfuegos
- Department of Kinesiology and Nutrition, University of Illinois at Chicago, Chicago, IL, USA
| | - Faiza Kalam
- Department of Kinesiology and Nutrition, University of Illinois at Chicago, Chicago, IL, USA
| | - Shuhao Lin
- Department of Kinesiology and Nutrition, University of Illinois at Chicago, Chicago, IL, USA
| | - Vasiliki Pavlou
- Department of Kinesiology and Nutrition, University of Illinois at Chicago, Chicago, IL, USA
| | - Zhenyuan Song
- Department of Kinesiology and Nutrition, University of Illinois at Chicago, Chicago, IL, USA
| | - Jacob M Haus
- School of Kinesiology, University of Michigan, Ann Arbor, MI, USA
| | - Sean Koppe
- Division of Gastroenterology and Hepatology, University of Illinois at Chicago, Chicago, IL, USA
| | - Shaina J Alexandria
- Department of Preventative Medicine (Biostatistics), Northwestern University, Chicago, IL, USA
| | - Lisa Tussing-Humphreys
- Department of Kinesiology and Nutrition, University of Illinois at Chicago, Chicago, IL, USA
| | - Krista A Varady
- Department of Kinesiology and Nutrition, University of Illinois at Chicago, Chicago, IL, USA.
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12
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Lee S, Bae J, Jo DR, Lee M, Lee YH, Kang ES, Cha BS, Lee BW. Impaired ketogenesis is associated with metabolic-associated fatty liver disease in subjects with type 2 diabetes. Front Endocrinol (Lausanne) 2023; 14:1124576. [PMID: 36896171 PMCID: PMC9989459 DOI: 10.3389/fendo.2023.1124576] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Accepted: 02/09/2023] [Indexed: 02/23/2023] Open
Abstract
AIMS The ketogenic pathway is an effective mechanism by which the liver disposes of fatty acids (FAs) to the peripheral tissues. Impaired ketogenesis is presumed to be related to the pathogenesis of metabolic-associated fatty liver disease (MAFLD), but the results of previous studies have been controversial. Therefore, we investigated the association between ketogenic capacity and MAFLD in subjects with type 2 diabetes (T2D). METHODS A total of 435 subjects with newly diagnosed T2D was recruited for the study. They were classified into two groups based on median serum β-hydroxybutyrate (β-HB) level: intact vs. impaired ketogenesis groups. The associations of baseline serum β-HB and MAFLD indices of hepatic steatosis index, NAFLD liver fat score (NLFS), Framingham Steatosis index (FSI), Zhejian University index, and Chinese NAFLD score were investigated. RESULTS Compared to the impaired ketogenesis group, the intact ketogenesis group showed better insulin sensitivity, lower serum triglyceride level, and higher low-density lipoprotein-cholesterol and glycated hemoglobin levels. Serum levels of liver enzymes were not different between the two groups. Of the hepatic steatosis indices, NLFS (0.8 vs. 0.9, p=0.045) and FSI (39.4 vs. 47.0: p=0.041) were significantly lower in the intact ketogenesis group. Moreover, intact ketogenesis was significantly associated with lower risk of MAFLD as calculated by FSI after adjusting for potential confounders (adjusted odds ratio 0.48, 95% confidence interval 0.25-0.91, p=0.025). CONCLUSIONS Our study suggests that intact ketogenesis might be associated with decreased risk of MAFLD in T2D.
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Affiliation(s)
- Sejeong Lee
- Division of Endocrinology and Metabolism, Department of Internal Medicine, CHA Gangnam Medical Center, CHA University School of Medicine, Seoul, Republic of Korea
| | - Jaehyun Bae
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Catholic Kwandong University College of Medicine, International St. Mary’s Hospital, Incheon, Republic of Korea
| | - Doo Ri Jo
- Department of diabetes mellitus, Biomedical Research Center, Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Minyoung Lee
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Yong-ho Lee
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Eun Seok Kang
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Bong-Soo Cha
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Byung-Wan Lee
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea
- *Correspondence: Byung-Wan Lee,
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13
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Mokhtari Z, Hosseini E, Hekmatdoost A, Haskey N, Gibson DL, Askari G. The effects of fasting diets on nonalcoholic fatty liver disease. Nutr Rev 2022:6809036. [DOI: 10.1093/nutrit/nuac092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Abstract
Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease in the world. There is no confirmed treatment for NAFLD as yet. Recently, fasting regimens and their relationship to NAFLD have drawn a great deal of attention in the literature. We review the current evidence that supports fasting diets as an adjunctive therapeutic strategy for patients with NAFLD and address potential action mechanisms. We reason that the fasting diets might be a promising approach for modulating hepatic steatosis, fibroblast growth factors 19 and 21 signaling, lipophagy, and the metabolic profile.
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Affiliation(s)
- Zeinab Mokhtari
- Nutrition and Food Security Research Center, Isfahan University of Medical Sciences are with the , Isfahan, Iran
| | - Elham Hosseini
- Nutrition and Food Security Research Center, Isfahan University of Medical Sciences are with the , Isfahan, Iran
| | - Azita Hekmatdoost
- Department of Clinical Nutrition and Dietetics, Faculty of Nutrition Sciences and, Food Technology, National Nutrition and Food Technology Research Institute, Shahid Beheshti University of Medical Sciences with the , Tehran, Iran
| | - Natasha Haskey
- Department of Biology, University of British Columbia—Okanagan Campus are with the , Kelowna, British Columbia, Canada
| | - Deanna L Gibson
- Department of Biology, University of British Columbia—Okanagan Campus are with the , Kelowna, British Columbia, Canada
| | - Gholamreza Askari
- Nutrition and Food Security Research Center, Isfahan University of Medical Sciences are with the , Isfahan, Iran
- Department of Community Nutrition, School of Nutrition and Food Science, Isfahan University of Medical Sciences with the , Isfahan, Iran
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14
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NMR-Based Metabolomics to Decipher the Molecular Mechanisms in the Action of Gut-Modulating Foods. Foods 2022; 11:foods11172707. [PMID: 36076892 PMCID: PMC9455659 DOI: 10.3390/foods11172707] [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: 08/08/2022] [Revised: 08/24/2022] [Accepted: 09/02/2022] [Indexed: 12/01/2022] Open
Abstract
Metabolomics deals with uncovering and characterizing metabolites present in a biological system, and is a leading omics discipline as it provides the nearest link to the biological phenotype. Within food and nutrition, metabolomics applied to fecal samples and bio-fluids has become an important tool to obtain insight into how food and food components may exert gut-modulating effects. This review aims to highlight how nuclear magnetic resonance (NMR)-based metabolomics in food and nutrition science may help us get beyond where we are today in understanding foods’ inherent, or added, biofunctionalities in relation to gut health.
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15
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Hughey CC, Puchalska P, Crawford PA. Integrating the contributions of mitochondrial oxidative metabolism to lipotoxicity and inflammation in NAFLD pathogenesis. Biochim Biophys Acta Mol Cell Biol Lipids 2022; 1867:159209. [DOI: 10.1016/j.bbalip.2022.159209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 06/25/2022] [Accepted: 07/27/2022] [Indexed: 11/28/2022]
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16
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Mooli RGR, Ramakrishnan SK. Emerging Role of Hepatic Ketogenesis in Fatty Liver Disease. Front Physiol 2022; 13:946474. [PMID: 35860662 PMCID: PMC9289363 DOI: 10.3389/fphys.2022.946474] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Accepted: 06/08/2022] [Indexed: 11/18/2022] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD), the most common chronic liver diseases, arise from non-alcoholic fatty liver (NAFL) characterized by excessive fat accumulation as triglycerides. Although NAFL is benign, it could progress to non-alcoholic steatohepatitis (NASH) manifested with inflammation, hepatocyte damage and fibrosis. A subset of NASH patients develops end-stage liver diseases such as cirrhosis and hepatocellular carcinoma. The pathogenesis of NAFLD is highly complex and strongly associated with perturbations in lipid and glucose metabolism. Lipid disposal pathways, in particular, impairment in condensation of acetyl-CoA derived from β-oxidation into ketogenic pathway strongly influence the hepatic lipid loads and glucose metabolism. Current evidence suggests that ketogenesis dispose up to two-thirds of the lipids entering the liver, and its dysregulation significantly contribute to the NAFLD pathogenesis. Moreover, ketone body administration in mice and humans shows a significant improvement in NAFLD. This review focuses on hepatic ketogenesis and its role in NAFLD pathogenesis. We review the possible mechanisms through which impaired hepatic ketogenesis may promote NAFLD progression. Finally, the review sheds light on the therapeutic implications of a ketogenic diet in NAFLD.
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17
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Grillet PE, Badiou S, Lambert K, Sutra T, Plawecki M, Raynaud de Mauverger E, Brun JF, Mercier J, Gouzi F, Cristol JP. Biomarkers of Redox Balance Adjusted to Exercise Intensity as a Useful Tool to Identify Patients at Risk of Muscle Disease through Exercise Test. Nutrients 2022; 14:1886. [PMID: 35565853 PMCID: PMC9105000 DOI: 10.3390/nu14091886] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 04/22/2022] [Accepted: 04/27/2022] [Indexed: 02/01/2023] Open
Abstract
The screening of skeletal muscle diseases constitutes an unresolved challenge. Currently, exercise tests or plasmatic tests alone have shown limited performance in the screening of subjects with an increased risk of muscle oxidative metabolism impairment. Intensity-adjusted energy substrate levels of lactate (La), pyruvate (Pyr), β-hydroxybutyrate (BOH) and acetoacetate (AA) during a cardiopulmonary exercise test (CPET) could constitute alternative valid biomarkers to select "at-risk" patients, requiring the gold-standard diagnosis procedure through muscle biopsy. Thus, we aimed to test: (1) the validity of the V'O2-adjusted La, Pyr, BOH and AA during a CPET for the assessment of the muscle oxidative metabolism (exercise and mitochondrial respiration parameters); and (2) the discriminative value of the V'O2-adjusted energy and redox markers, as well as five other V'O2-adjusted TCA cycle-related metabolites, between healthy subjects, subjects with muscle complaints and muscle disease patients. Two hundred and thirty subjects with muscle complaints without diagnosis, nine patients with a diagnosed muscle disease and ten healthy subjects performed a CPET with blood assessments at rest, at the estimated 1st ventilatory threshold and at the maximal intensity. Twelve subjects with muscle complaints presenting a severe alteration of their profile underwent a muscle biopsy. The V'O2-adjusted plasma levels of La, Pyr, BOH and AA, and their respective ratios showed significant correlations with functional and muscle fiber mitochondrial respiration parameters. Differences in exercise V'O2-adjusted La/Pyr, BOH, AA and BOH/AA were observed between healthy subjects, subjects with muscle complaints without diagnosis and muscle disease patients. The energy substrate and redox blood profile of complaining subjects with severe exercise intolerance matched the blood profile of muscle disease patients. Adding five tricarboxylic acid cycle intermediates did not improve the discriminative value of the intensity-adjusted energy and redox markers. The V'O2-adjusted La, Pyr, BOH, AA and their respective ratios constitute valid muscle biomarkers that reveal similar blunted adaptations in muscle disease patients and in subjects with muscle complaints and severe exercise intolerance. A targeted metabolomic approach to improve the screening of "at-risk" patients is discussed.
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Affiliation(s)
- Pierre-Edouard Grillet
- PhyMedExp, INSERM U1046, CNRS UMR 9214, University of Montpellier, CHU Montpellier, 34295 Montpellier, France; (P.-E.G.); (S.B.); (K.L.); (T.S.); (M.P.); (E.R.d.M.); (J.-F.B.); (J.M.); (J.-P.C.)
- Department of Biochemistry and Hormonology, CHU Montpellier, 34295 Montpellier, France
| | - Stéphanie Badiou
- PhyMedExp, INSERM U1046, CNRS UMR 9214, University of Montpellier, CHU Montpellier, 34295 Montpellier, France; (P.-E.G.); (S.B.); (K.L.); (T.S.); (M.P.); (E.R.d.M.); (J.-F.B.); (J.M.); (J.-P.C.)
- Department of Biochemistry and Hormonology, CHU Montpellier, 34295 Montpellier, France
| | - Karen Lambert
- PhyMedExp, INSERM U1046, CNRS UMR 9214, University of Montpellier, CHU Montpellier, 34295 Montpellier, France; (P.-E.G.); (S.B.); (K.L.); (T.S.); (M.P.); (E.R.d.M.); (J.-F.B.); (J.M.); (J.-P.C.)
| | - Thibault Sutra
- PhyMedExp, INSERM U1046, CNRS UMR 9214, University of Montpellier, CHU Montpellier, 34295 Montpellier, France; (P.-E.G.); (S.B.); (K.L.); (T.S.); (M.P.); (E.R.d.M.); (J.-F.B.); (J.M.); (J.-P.C.)
- Department of Biochemistry and Hormonology, CHU Montpellier, 34295 Montpellier, France
| | - Maëlle Plawecki
- PhyMedExp, INSERM U1046, CNRS UMR 9214, University of Montpellier, CHU Montpellier, 34295 Montpellier, France; (P.-E.G.); (S.B.); (K.L.); (T.S.); (M.P.); (E.R.d.M.); (J.-F.B.); (J.M.); (J.-P.C.)
- Department of Biochemistry and Hormonology, CHU Montpellier, 34295 Montpellier, France
| | - Eric Raynaud de Mauverger
- PhyMedExp, INSERM U1046, CNRS UMR 9214, University of Montpellier, CHU Montpellier, 34295 Montpellier, France; (P.-E.G.); (S.B.); (K.L.); (T.S.); (M.P.); (E.R.d.M.); (J.-F.B.); (J.M.); (J.-P.C.)
- Department of Physiology, University of Montpellier, CHU Montpellier, 34295 Montpellier, France
| | - Jean-Frédéric Brun
- PhyMedExp, INSERM U1046, CNRS UMR 9214, University of Montpellier, CHU Montpellier, 34295 Montpellier, France; (P.-E.G.); (S.B.); (K.L.); (T.S.); (M.P.); (E.R.d.M.); (J.-F.B.); (J.M.); (J.-P.C.)
- Department of Physiology, University of Montpellier, CHU Montpellier, 34295 Montpellier, France
| | - Jacques Mercier
- PhyMedExp, INSERM U1046, CNRS UMR 9214, University of Montpellier, CHU Montpellier, 34295 Montpellier, France; (P.-E.G.); (S.B.); (K.L.); (T.S.); (M.P.); (E.R.d.M.); (J.-F.B.); (J.M.); (J.-P.C.)
- Department of Physiology, University of Montpellier, CHU Montpellier, 34295 Montpellier, France
| | - Fares Gouzi
- PhyMedExp, INSERM U1046, CNRS UMR 9214, University of Montpellier, CHU Montpellier, 34295 Montpellier, France; (P.-E.G.); (S.B.); (K.L.); (T.S.); (M.P.); (E.R.d.M.); (J.-F.B.); (J.M.); (J.-P.C.)
- Department of Physiology, University of Montpellier, CHU Montpellier, 34295 Montpellier, France
| | - Jean-Paul Cristol
- PhyMedExp, INSERM U1046, CNRS UMR 9214, University of Montpellier, CHU Montpellier, 34295 Montpellier, France; (P.-E.G.); (S.B.); (K.L.); (T.S.); (M.P.); (E.R.d.M.); (J.-F.B.); (J.M.); (J.-P.C.)
- Department of Biochemistry and Hormonology, CHU Montpellier, 34295 Montpellier, France
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18
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Asif S, Kim RY, Fatica T, Sim J, Zhao X, Oh Y, Denoncourt A, Cheung A, Downey M, Mulvihill EE, Kim KH. Hmgcs2-mediated ketogenesis modulates high-fat diet-induced hepatosteatosis. Mol Metab 2022; 61:101494. [PMID: 35421611 PMCID: PMC9039870 DOI: 10.1016/j.molmet.2022.101494] [Citation(s) in RCA: 35] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 04/01/2022] [Accepted: 04/04/2022] [Indexed: 12/11/2022] Open
Abstract
OBJECTIVE Aberrant ketogenesis is correlated with the degree of steatosis in NAFLD patients, and an inborn error of ketogenesis (mitochondrial HMG-CoA synthase deficiency) is commonly associated with the development of the fatty liver. Here we aimed to determine the impact of Hmgcs2-mediated ketogenesis and its modulations on the development and treatment of fatty liver disease. METHODS Loss- and gain-of-ketogenic function through in vivo and in vitro models, achieved by Hmgcs2 knockout and overexpression, respectively, were examined to investigate the role of ketogenesis in the hepatic lipid accumulation during neonatal development and the diet-induced NAFLD mouse model. RESULTS Ketogenic function was decreased in NAFLD mice with a reduction in Hmgcs2 expression. Mice lacking Hmgcs2 developed spontaneous fatty liver phenotype during postnatal development, which was rescued by a shift to a low-fat dietary composition via early weaning. Hmgcs2 heterozygous mice, which exhibited reduced ketogenic activity, were more susceptible to diet-induced NAFLD development, whereas HMGCS2 overexpression in NAFLD mice improved hepatosteatosis and glucose homeostasis. CONCLUSIONS Our study adds new knowledge to the field of ketone body metabolism and shows that Hmgcs2-mediated ketogenesis modulates hepatic lipid regulation under a fat-enriched nutritional environment. The regulation of hepatic ketogenesis may be a viable therapeutic strategy in the prevention and treatment of hepatosteatosis.
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Affiliation(s)
- Shaza Asif
- University of Ottawa Heart Institute, Ottawa, ON, K1Y 4W7, Canada; Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, K1H 8M5, Canada
| | - Ri Youn Kim
- University of Ottawa Heart Institute, Ottawa, ON, K1Y 4W7, Canada
| | - Thet Fatica
- University of Ottawa Heart Institute, Ottawa, ON, K1Y 4W7, Canada
| | - Jordan Sim
- Department of Pathology and Laboratory Medicine, The Ottawa Hospital, Ottawa, ON, K1H 8M5, Canada
| | - Xiaoling Zhao
- University of Ottawa Heart Institute, Ottawa, ON, K1Y 4W7, Canada
| | - Yena Oh
- University of Ottawa Heart Institute, Ottawa, ON, K1Y 4W7, Canada; Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, K1H 8M5, Canada
| | - Alix Denoncourt
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, K1H 8M5, Canada; Ottawa Institute of Systems Biology, Ottawa, ON, K1H 8M5, Canada
| | - Angela Cheung
- Gastroenterology and Hepatology, Department of Medicine, The Ottawa Hospital, Ottawa, ON, K1H 8M5, Canada; The Ottawa Hospital Research Institute, Chronic Disease Program, Ottawa, ON, K1Y 4E9, Canada
| | - Michael Downey
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, K1H 8M5, Canada; Ottawa Institute of Systems Biology, Ottawa, ON, K1H 8M5, Canada
| | - Erin E Mulvihill
- University of Ottawa Heart Institute, Ottawa, ON, K1Y 4W7, Canada; Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON, K1H 8M5, Canada
| | - Kyoung-Han Kim
- University of Ottawa Heart Institute, Ottawa, ON, K1Y 4W7, Canada; Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, K1H 8M5, Canada.
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19
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Hamblin PS, Wong R, Ekinci EI, Sztal-Mazer S, Balachandran S, Frydman A, Hanrahan TP, Hu R, Ket SN, Moss A, Ng M, Ragunathan S, Bach LA. Body mass index is inversely associated with capillary ketones at the time of colonoscopy: Implications for SGLT2i use. Clin Endocrinol (Oxf) 2022; 96:549-557. [PMID: 34697809 DOI: 10.1111/cen.14621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2021] [Revised: 09/18/2021] [Accepted: 09/29/2021] [Indexed: 11/30/2022]
Abstract
OBJECTIVE Sodium-glucose cotransporter 2 inhibitors (SGLT2i) have been associated with diabetic ketoacidosis at the time of colonoscopy. This study aimed to identify factors associated with ketone concentrations in SGLT2i-treated type 2 diabetes compared with non-SGLT2i-treated diabetes, and those with impaired fasting glycaemia (IFG) and normoglycaemia. DESIGN Cross-sectional, multicentre, observational study June-December 2020 in four Australian tertiary hospitals. PARTICIPANTS Capillary glucose and ketones were measured in people undergoing colonoscopy: 37 SGLT2i-treated and 105 non-SGLT2i-treated type 2 diabetes, 65 IFG and 151 normoglycaemia. MEASUREMENTS Body mass index (BMI), age, glucose, fasting duration and where relevant, HbA1c and time since last SGLT2i dose. RESULTS In SGLT2i-treated diabetes, BMI (ρ = -0.43 [95% confidence interval: -0.67, -0.11]) and duration since last SGLT2i dose (ρ = -0.33 [-0.60, 0.00]) correlated negatively with increasing ketones, but there was no correlation with fasting duration. In non-SGLT2i-treated diabetes, BMI correlated negatively (ρ = -0.24 [-0.42, -0.05]) and fasting duration positively (ρ = 0.26 [0.07, 0.43]) with ketones. In IFG participants, only fasting duration correlated with ketones (ρ = 0.28 [0.03, 0.49]). In normoglycaemic participants, there were negative correlations with BMI (ρ = -0.20 [-0.35, -0.04]) and fasting glucose (ρ = -0.31 [-0.45, -0.15]) and positive correlations with fasting duration (ρ = 0.20 [0.04, 0.35]) and age (ρ = 0.19 [0.03, 0.34]). Multiple regression analysis of the entire cohort showed BMI, age and fasting glucose remained independently associated with ketones, but in SGLT2i-treated participants only BMI remained independently associated. CONCLUSIONS In SGLT2i-treated diabetes, lower BMI was a novel risk factor for higher ketones precolonoscopy. Pending larger confirmatory studies, extra vigilance for ketoacidosis is warranted in these people.
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Affiliation(s)
- Peter S Hamblin
- Department of Endocrinology and Diabetes, Western Health, Melbourne, Victoria, Australia
- Department of Medicine, Western Health, The University of Melbourne, Melbourne, Victoria, Australia
| | - Rosemary Wong
- Department of Endocrinology and Diabetes, Eastern Health, Melbourne, Victoria, Australia
- Department of Medicine, Faculty of Medicine, Nursing and Health Sciences, Monash University, Melbourne, Victoria, Australia
| | - Elif I Ekinci
- Department of Endocrinology, Austin Health, Melbourne, Victoria, Australia
- Department of Medicine, Melbourne Medical School, The University of Melbourne, Melbourne, Victoria, Australia
| | - Shoshana Sztal-Mazer
- Department of Endocrinology and Diabetes, Alfred Health, Melbourne, Victoria, Australia
- School of Public Health and Preventive Medicine, Faculty of Medicine, Nursing and Health Sciences, Monash University, Melbourne, Victoria, Australia
- Department of Medicine, Central Clinical School, Faculty of Medicine, Nursing and Health Sciences, Monash University, Melbourne, Victoria, Australia
| | | | - Aviva Frydman
- Department of Endocrinology and Diabetes, Western Health, Melbourne, Victoria, Australia
| | - Timothy P Hanrahan
- Department of Gastroenterology and Liver Transplant Unit, Austin Health, Melbourne, Victoria, Australia
| | - Raymond Hu
- Department of Medicine, Melbourne Medical School, The University of Melbourne, Melbourne, Victoria, Australia
- Department of Anaesthesia, Austin Health, Melbourne, Victoria, Australia
| | - Shara N Ket
- Department of Gastroenterology, Alfred Health, Melbourne, Victoria, Australia
| | - Alan Moss
- Department of Medicine, Western Health, The University of Melbourne, Melbourne, Victoria, Australia
- Department of Endoscopic Services, Western Health, Melbourne, Victoria, Australia
| | - Mark Ng
- Department of Medicine, Faculty of Medicine, Nursing and Health Sciences, Monash University, Melbourne, Victoria, Australia
- Department of Anaesthesia, Pain and Perioperative Medicine, Eastern Health, Melbourne, Victoria, Australia
| | - Sashikala Ragunathan
- Department of Gastroenterology, Austin Health, Melbourne, Victoria, Australia
- Gastroenterological Nurses College of Australia, Melbourne, Victoria, Australia
| | - Leon A Bach
- Department of Endocrinology and Diabetes, Alfred Health, Melbourne, Victoria, Australia
- Department of Medicine (Alfred), Monash University, Melbourne, Victoria, Australia
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Yu L, Hong W, Lu S, Li Y, Guan Y, Weng X, Feng Z. The NLRP3 Inflammasome in Non-Alcoholic Fatty Liver Disease and Steatohepatitis: Therapeutic Targets and Treatment. Front Pharmacol 2022; 13:780496. [PMID: 35350750 PMCID: PMC8957978 DOI: 10.3389/fphar.2022.780496] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Accepted: 02/17/2022] [Indexed: 12/12/2022] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) is among the most prevalent primary liver diseases worldwide and can develop into various conditions, ranging from simple steatosis, through non-alcoholic steatohepatitis (NASH), to fibrosis, and eventually cirrhosis and hepatocellular carcinoma. Nevertheless, there is no effective treatment for NAFLD due to the complicated etiology. Recently, activation of the NLPR3 inflammasome has been demonstrated to be a contributing factor in the development of NAFLD, particularly as a modulator of progression from initial hepatic steatosis to NASH. NLRP3 inflammasome, as a caspase-1 activation platform, is critical for processing key pro-inflammatory cytokines and pyroptosis. Various stimuli involved in NAFLD can activate the NLRP3 inflammasome, depending on the diverse cellular stresses that they cause. NLRP3 inflammasome-related inhibitors and agents for NAFLD treatment have been tested and demonstrated positive effects in experimental models. Meanwhile, some drugs have been applied in clinical studies, supporting this therapeutic approach. In this review, we discuss the activation, biological functions, and treatment targeting the NLRP3 inflammasome in the context of NAFLD progression. Specifically, we focus on the different types of therapeutic agents that can inhibit the NLRP3 inflammasome and summarize their pharmacological effectiveness for NAFLD treatment.
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Affiliation(s)
- Lili Yu
- School of Basic Medical Sciences, Xinxiang Medical University, Xinxiang, China.,Institute of Precision Medicine, Xinxiang Medical University, Xinxiang, China.,The Third Clinical College of Xinxiang Medical University, Xinxiang, China.,Xinxiang Key Laboratory of Tumor Vaccine and Immunotherapy, Xinxiang Medical University, Xinxiang, China
| | - Wei Hong
- School of Basic Medical Sciences, Xinxiang Medical University, Xinxiang, China.,Institute of Precision Medicine, Xinxiang Medical University, Xinxiang, China
| | - Shen Lu
- The Third Clinical College of Xinxiang Medical University, Xinxiang, China
| | - Yanrong Li
- School of Basic Medical Sciences, Xinxiang Medical University, Xinxiang, China.,Institute of Precision Medicine, Xinxiang Medical University, Xinxiang, China
| | - Yaya Guan
- The Third Clinical College of Xinxiang Medical University, Xinxiang, China
| | - Xiaogang Weng
- The Third Clinical College of Xinxiang Medical University, Xinxiang, China
| | - Zhiwei Feng
- School of Basic Medical Sciences, Xinxiang Medical University, Xinxiang, China.,Institute of Precision Medicine, Xinxiang Medical University, Xinxiang, China.,Xinxiang Key Laboratory of Tumor Vaccine and Immunotherapy, Xinxiang Medical University, Xinxiang, China
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21
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Zhao Y, Jia M, Chen W, Liu Z. The neuroprotective effects of intermittent fasting on brain aging and neurodegenerative diseases via regulating mitochondrial function. Free Radic Biol Med 2022; 182:206-218. [PMID: 35218914 DOI: 10.1016/j.freeradbiomed.2022.02.021] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Revised: 01/29/2022] [Accepted: 02/21/2022] [Indexed: 12/11/2022]
Abstract
Intermittent fasting (IF) has been studied for its effects on lifespan and the prevention or delay of age-related diseases upon the regulation of metabolic pathways. Mitochondria participate in key metabolic pathways and play important roles in maintaining intracellular signaling networks that modulate various cellular functions. Mitochondrial dysfunction has been described as an early feature of brain aging and neurodegeneration. Although IF has been shown to prevent brain aging and neurodegeneration, the mechanism is still unclear. This review focuses on the mechanisms by which IF improves mitochondrial function, which plays a central role in brain aging and neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease, and Huntington's disease. The cellular and molecular mechanisms of IF in brain aging and neurodegeneration involve activation of adaptive cellular stress responses and signaling- and transcriptional pathways, thereby enhancing mitochondrial function, by promoting energy metabolism and reducing oxidant production.
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Affiliation(s)
- Yihang Zhao
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi, China
| | - Mengzhen Jia
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi, China
| | - Weixuan Chen
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi, China
| | - Zhigang Liu
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi, China; German Institute of Human Nutrition Potsdam-Rehbruecke, Nuthetal, Germany.
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22
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Post A, Garcia E, van den Berg EH, Flores-Guerrero JL, Gruppen EG, Groothof D, Westenbrink BD, Connelly MA, Bakker SJL, Dullaart RPF. Nonalcoholic fatty liver disease, circulating ketone bodies and all-cause mortality in a general population-based cohort. Eur J Clin Invest 2021; 51:e13627. [PMID: 34120339 PMCID: PMC9285047 DOI: 10.1111/eci.13627] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2021] [Revised: 04/28/2021] [Accepted: 05/02/2021] [Indexed: 02/07/2023]
Abstract
BACKGROUND Nonalcoholic fatty liver disease (NAFLD) is increasingly prevalent, paralleling the obesity epidemic. Ketone bodies are produced in the liver, but it is currently uncertain whether circulating ketone bodies are increased in the context of NAFLD. We investigated the association between NAFLD and circulating ketone bodies and determined the extent to which NAFLD and circulating ketone bodies are associated with all-cause mortality. METHODS Plasma ketone bodies were measured by nuclear magnetic resonance spectroscopy in participants of the general population-based PREVEND study. A fatty liver index (FLI) ≥60 was regarded as a proxy of NAFLD. Associations of an elevated FLI and ketone bodies with all-cause mortality were investigated using Cox regression analyses. RESULTS The study included 6,297 participants aged 54 ± 12 years, of whom 1,970 (31%) had elevated FLI. Participants with elevated FLI had higher total ketone bodies (194 [153-259] vs 170 [133-243] µmol/L; P < .001) than participants without elevated FLI. During 7.9 [7.8-8.9] years of follow-up, 387 (6%) participants died. An elevated FLI was independently associated with an increased risk of mortality (HR: 1.34 [1.06-1.70]; P = .02). Higher total ketone bodies were also associated with an increased mortality risk (HR per doubling: 1.29 [1.12-1.49]; P < .001). Mediation analysis suggested that the association of elevated FLI with all-cause mortality was in part mediated by ketone bodies (proportion mediated: 10%, P < .001). CONCLUSION Circulating ketone bodies were increased in participants with suspected NAFLD. Both suspected NAFLD and higher circulating ketone bodies are associated with an increased risk of all-cause mortality.
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Affiliation(s)
- Adrian Post
- Department of Internal Medicine, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Erwin Garcia
- Laboratory Corporation of America Holdings (Labcorp), Morrisville, NC, USA
| | - Eline H van den Berg
- Department of Gastroenterology and Hepatology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Jose L Flores-Guerrero
- Department of Internal Medicine, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Eke G Gruppen
- Department of Internal Medicine, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Dion Groothof
- Department of Internal Medicine, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Berend Daan Westenbrink
- Department of Cardiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Margery A Connelly
- Laboratory Corporation of America Holdings (Labcorp), Morrisville, NC, USA
| | - Stephan J L Bakker
- Department of Internal Medicine, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Robin P F Dullaart
- Department of Internal Medicine, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
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23
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Semmler G, Datz C, Reiberger T, Trauner M. Diet and exercise in NAFLD/NASH: Beyond the obvious. Liver Int 2021; 41:2249-2268. [PMID: 34328248 PMCID: PMC9292198 DOI: 10.1111/liv.15024] [Citation(s) in RCA: 66] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 07/06/2021] [Accepted: 07/10/2021] [Indexed: 12/12/2022]
Abstract
Lifestyle represents the most relevant factor for non-alcoholic fatty liver disease (NAFLD) as the hepatic manifestation of the metabolic syndrome. Although a tremendous body of clinical and preclinical data on the effectiveness of dietary and lifestyle interventions exist, the complexity of this topic makes firm and evidence-based clinical recommendations for nutrition and exercise in NAFLD difficult. The aim of this review is to guide readers through the labyrinth of recent scientific findings on diet and exercise in NAFLD and non-alcoholic steatohepatitis (NASH), summarizing "obvious" findings in a holistic manner and simultaneously highlighting stimulating aspects of clinical and translational research "beyond the obvious". Specifically, the importance of calorie restriction regardless of dietary composition and evidence from low-carbohydrate diets to target the incidence and severity of NAFLD are discussed. The aspect of ketogenesis-potentially achieved via intermittent calorie restriction-seems to be a central aspect of these diets warranting further investigation. Interactions of diet and exercise with the gut microbiota and the individual genetic background need to be comprehensively understood in order to develop personalized dietary concepts and exercise strategies for patients with NAFLD/NASH.
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Affiliation(s)
- Georg Semmler
- Division of Gastroenterology and HepatologyDepartment of Internal Medicine IIIMedical University of ViennaViennaAustria
| | - Christian Datz
- Department of Internal MedicineGeneral Hospital OberndorfTeaching Hospital of the Paracelsus Medical University SalzburgSalzburgAustria
| | - Thomas Reiberger
- Division of Gastroenterology and HepatologyDepartment of Internal Medicine IIIMedical University of ViennaViennaAustria
| | - Michael Trauner
- Division of Gastroenterology and HepatologyDepartment of Internal Medicine IIIMedical University of ViennaViennaAustria
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24
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Wang L, Chen P, Xiao W. β-hydroxybutyrate as an Anti-Aging Metabolite. Nutrients 2021; 13:nu13103420. [PMID: 34684426 PMCID: PMC8540704 DOI: 10.3390/nu13103420] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2021] [Revised: 09/25/2021] [Accepted: 09/26/2021] [Indexed: 12/18/2022] Open
Abstract
The ketone bodies, especially β-hydroxybutyrate (β-HB), derive from fatty acid oxidation and alternatively serve as a fuel source for peripheral tissues including the brain, heart, and skeletal muscle. β-HB is currently considered not solely an energy substrate for maintaining metabolic homeostasis but also acts as a signaling molecule of modulating lipolysis, oxidative stress, and neuroprotection. Besides, it serves as an epigenetic regulator in terms of histone methylation, acetylation, β-hydroxybutyrylation to delay various age-related diseases. In addition, studies support endogenous β-HB administration or exogenous supplementation as effective strategies to induce a metabolic state of nutritional ketosis. The purpose of this review article is to provide an overview of β-HB metabolism and its relationship and application in age-related diseases. Future studies are needed to reveal whether β-HB has the potential to serve as adjunctive nutritional therapy for aging.
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Affiliation(s)
| | - Peijie Chen
- Correspondence: (P.C.); (W.X.); Tel.: +86-021-65508039 (P.C.); +86-021-65507367 (W.X.)
| | - Weihua Xiao
- Correspondence: (P.C.); (W.X.); Tel.: +86-021-65508039 (P.C.); +86-021-65507367 (W.X.)
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25
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Wang L, Chen P, Xiao W. β-hydroxybutyrate as an Anti-Aging Metabolite. Nutrients 2021; 13:3420. [PMID: 34684426 PMCID: PMC8540704 DOI: 10.3390/nu13103420&set/a 930838900+926910489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/16/2023] Open
Abstract
The ketone bodies, especially β-hydroxybutyrate (β-HB), derive from fatty acid oxidation and alternatively serve as a fuel source for peripheral tissues including the brain, heart, and skeletal muscle. β-HB is currently considered not solely an energy substrate for maintaining metabolic homeostasis but also acts as a signaling molecule of modulating lipolysis, oxidative stress, and neuroprotection. Besides, it serves as an epigenetic regulator in terms of histone methylation, acetylation, β-hydroxybutyrylation to delay various age-related diseases. In addition, studies support endogenous β-HB administration or exogenous supplementation as effective strategies to induce a metabolic state of nutritional ketosis. The purpose of this review article is to provide an overview of β-HB metabolism and its relationship and application in age-related diseases. Future studies are needed to reveal whether β-HB has the potential to serve as adjunctive nutritional therapy for aging.
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Affiliation(s)
| | - Peijie Chen
- Correspondence: (P.C.); (W.X.); Tel.: +86-021-65508039 (P.C.); +86-021-65507367 (W.X.)
| | - Weihua Xiao
- Correspondence: (P.C.); (W.X.); Tel.: +86-021-65508039 (P.C.); +86-021-65507367 (W.X.)
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26
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β-hydroxybutyrate as an Anti-Aging Metabolite. Nutrients 2021. [DOI: 10.3390/nu13103420
expr 933295879 + 814156476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/16/2023] Open
Abstract
The ketone bodies, especially β-hydroxybutyrate (β-HB), derive from fatty acid oxidation and alternatively serve as a fuel source for peripheral tissues including the brain, heart, and skeletal muscle. β-HB is currently considered not solely an energy substrate for maintaining metabolic homeostasis but also acts as a signaling molecule of modulating lipolysis, oxidative stress, and neuroprotection. Besides, it serves as an epigenetic regulator in terms of histone methylation, acetylation, β-hydroxybutyrylation to delay various age-related diseases. In addition, studies support endogenous β-HB administration or exogenous supplementation as effective strategies to induce a metabolic state of nutritional ketosis. The purpose of this review article is to provide an overview of β-HB metabolism and its relationship and application in age-related diseases. Future studies are needed to reveal whether β-HB has the potential to serve as adjunctive nutritional therapy for aging.
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27
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Huang TY, Linden MA, Fuller SE, Goldsmith FR, Simon J, Batdorf HM, Scott MC, Essajee NM, Brown JM, Noland RC. Combined effects of a ketogenic diet and exercise training alter mitochondrial and peroxisomal substrate oxidative capacity in skeletal muscle. Am J Physiol Endocrinol Metab 2021; 320:E1053-E1067. [PMID: 33843280 PMCID: PMC8285595 DOI: 10.1152/ajpendo.00410.2020] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Ketogenic diets (KDs) are reported to improve body weight, fat mass, and exercise performance in humans. Unfortunately, most rodent studies have used a low-protein KD, which does not recapitulate diets used by humans. Since skeletal muscle plays a critical role in responding to macronutrient perturbations induced by diet and exercise, the purpose of this study was to test if a normal-protein KD (NPKD) impacts shifts in skeletal muscle substrate oxidative capacity in response to exercise training (ExTr). A high fat, carbohydrate-deficient NPKD (16.1% protein, 83.9% fat, 0% carbohydrate) was given to C57BL/6J male mice for 6 wk, whereas controls (Con) received a low-fat diet with similar protein (15.9% protein, 11.9% fat, 72.2% carbohydrate). After 3 wk on the diet, mice began treadmill training 5 days/wk, 60 min/day for 3 wks. The NPKD increased body weight and fat mass, whereas ExTr negated a continued rise in adiposity. ExTr increased intramuscular glycogen, whereas the NPKD increased intramuscular triglycerides. Neither the NPKD nor ExTr alone altered mitochondrial content; however, in combination, the NPKD-ExTr group showed increases in PGC-1α and markers of mitochondrial fission/fusion. Pyruvate oxidative capacity was unchanged by either intervention, whereas ExTr increased leucine oxidation in NPKD-fed mice. Lipid metabolism pathways had the most notable changes as the NPKD and ExTr interventions both enhanced mitochondrial and peroxisomal lipid oxidation and many adaptations were additive or synergistic. Overall, these results suggest that a combination of a NPKD and ExTr induces additive and/or synergistic adaptations in skeletal muscle oxidative capacity.NEW & NOTEWORTHY A ketogenic diet with normal protein content (NPKD) increases body weight and fat mass, increases intramuscular triglyceride storage, and upregulates pathways related to protein metabolism. In combination with exercise training, a NPKD induces additive and/or synergistic activation of AMPK, PGC-1α, mitochondrial fission/fusion genes, mitochondrial fatty acid oxidation, and peroxisomal adaptations in skeletal muscle. Collectively, results from this study provide mechanistic insight into adaptations in skeletal muscle relevant to keto-adaptation.
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Affiliation(s)
- Tai-Yu Huang
- Skeletal Muscle Metabolism Laboratory, Pennington Biomedical Research Center, Baton Rouge, Louisiana
| | - Melissa A Linden
- Skeletal Muscle Metabolism Laboratory, Pennington Biomedical Research Center, Baton Rouge, Louisiana
| | - Scott E Fuller
- Skeletal Muscle Metabolism Laboratory, Pennington Biomedical Research Center, Baton Rouge, Louisiana
| | - Felicia R Goldsmith
- Skeletal Muscle Metabolism Laboratory, Pennington Biomedical Research Center, Baton Rouge, Louisiana
| | - Jacob Simon
- Skeletal Muscle Metabolism Laboratory, Pennington Biomedical Research Center, Baton Rouge, Louisiana
| | - Heidi M Batdorf
- Skeletal Muscle Metabolism Laboratory, Pennington Biomedical Research Center, Baton Rouge, Louisiana
| | - Matthew C Scott
- Skeletal Muscle Metabolism Laboratory, Pennington Biomedical Research Center, Baton Rouge, Louisiana
| | - Nabil M Essajee
- Skeletal Muscle Metabolism Laboratory, Pennington Biomedical Research Center, Baton Rouge, Louisiana
| | - John M Brown
- Skeletal Muscle Metabolism Laboratory, Pennington Biomedical Research Center, Baton Rouge, Louisiana
| | - Robert C Noland
- Skeletal Muscle Metabolism Laboratory, Pennington Biomedical Research Center, Baton Rouge, Louisiana
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POFFÉ CHIEL, WYNS FELIX, RAMAEKERS MONIQUE, HESPEL PETER. Exogenous Ketosis Impairs 30-min Time-Trial Performance Independent of Bicarbonate Supplementation. Med Sci Sports Exerc 2021; 53:1068-1078. [PMID: 33196605 PMCID: PMC8048725 DOI: 10.1249/mss.0000000000002552] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
PURPOSE We recently demonstrated that coingestion of NaHCO3 to counteract ketoacidosis resulting from oral ketone ester (KE) intake improves mean power output during a 15-min time trial (TT) at the end of a 3-h cycling race by ~5%. This ergogenic effect occurred at a time when blood ketone levels were low, as ketosis was only induced during the initial ~2 h of the race. Therefore, in the current study, we investigated whether performance also increases if blood ketone levels are increased in the absence of ketoacidosis during high-intensity exercise. METHODS In a double-blind crossover design, 14 well-trained male cyclists completed a 30-min TT (TT30') followed by an all-out sprint at 175% of lactate threshold (SPRINT). Subjects were randomized to receive (i) 50 g KE, (ii) 180 mg·kg-1 body weight NaHCO3 (BIC), (iii) KE + BIC, or (iv) a control drink (CON). RESULTS KE ingestion increased blood d-ß-hydroxybutyrate to ~3-4 mM during the TT30' and SPRINT (P < 0.001 vs CON). In KE, blood pH and bicarbonate concomitantly dropped, causing 0.05 units lower pH and 2.6 mM lower bicarbonate in KE compared with CON during the TT30' and SPRINT (P < 0.001 vs CON). BIC coingestion resulted in 0.9 mM higher blood d-ß-hydroxybutyrate (P < 0.001 vs KE) and completely counteracted ketoacidosis during exercise (P > 0.05 vs CON). Mean power output during TT30' was similar between CON and BIC at 281 W, but was 1.5% lower in the KE conditions (main effect of KE: P = 0.03). Time to exhaustion in the SPRINT was ~64 s in CON and KE and increased by ~8% in the BIC conditions (main effect of BIC: P < 0.01). DISCUSSION Neutralization of acid-base disturbance by BIC coingestion is insufficient to counteract the slightly negative effect of KE intake during high-intensity exercise.
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Affiliation(s)
- CHIEL POFFÉ
- Exercise Physiology Research Group, Department of Movement Sciences, KU Leuven, Leuven, BELGIUM
| | - FELIX WYNS
- Bakala Academy-Athletic Performance Center, KU Leuven, Leuven, BELGIUM
| | - MONIQUE RAMAEKERS
- Exercise Physiology Research Group, Department of Movement Sciences, KU Leuven, Leuven, BELGIUM
| | - PETER HESPEL
- Exercise Physiology Research Group, Department of Movement Sciences, KU Leuven, Leuven, BELGIUM
- Bakala Academy-Athletic Performance Center, KU Leuven, Leuven, BELGIUM
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Autonomic and Perceptual Responses to Induction of a Ketogenic Diet in Free-Living Endurance Athletes: A Randomized, Crossover Trial. Int J Sports Physiol Perform 2021; 16:1603-1609. [PMID: 33873154 DOI: 10.1123/ijspp.2020-0814] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 12/02/2020] [Accepted: 12/10/2020] [Indexed: 11/18/2022]
Abstract
PURPOSE Considerable interindividual heterogeneity has been observed in endurance performance responses following induction of a ketogenic diet (KD). It is plausible that a physiological stress response in the period following the dramatic dietary shift associated with transition to a KD may explain this heterogeneity. METHODS In a randomized, crossover study design, 8 trained male runners completed an incremental exercise test and ran to exhaustion at 70%VO2max before and after a 31-day rigorously controlled habitual diet or KD intervention, and recorded heart rate variability (root mean square of the sum of successive differences in R-R intervals [rMSSD]) upon waking each morning along with the recovery-stress questionnaire for athletes each week. Data were analyzed using linear mixed models. RESULTS A significant reduction in rMSSD was observed in the KD (-9.77 [4.03] ms, P = .02), along with an increase in day-to-day variability in rMSSD (2.1% [1.0%], P = .03). The reduction in rMSSD in the KD for the subgroup of individuals exhibiting impaired exercise capacity following induction of the KD approached significance (Δ -22 [15] ms, P = .06, N = 4); whereas no effect was observed in those who exhibited unchanged exercise capacity (Δ 5 [18] ms, P = .61, N = 4). No main effects were observed for recovery-stress questionnaire for athletes. CONCLUSIONS Our data suggest those working with endurance athletes transitioning onto a KD may consider using noninvasive, inexpensive resting heart rate variability measures to gain individual-level insights into the likely short-term effects on exercise capacity.
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Ketogenic Diet Suppressed T-Regulatory Cells and Promoted Cardiac Fibrosis via Reducing Mitochondria-Associated Membranes and Inhibiting Mitochondrial Function. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2021; 2021:5512322. [PMID: 33959215 PMCID: PMC8075689 DOI: 10.1155/2021/5512322] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 02/28/2021] [Accepted: 03/22/2021] [Indexed: 02/05/2023]
Abstract
Ketogenic diet (KD) is popular in diabetic patients but its cardiac safety and efficiency on the heart are unknown. The aim of the present study is to determine the effects and the underlined mechanisms of KD on cardiac function in diabetic cardiomyopathy (DCM). We used db/db mice to model DCM, and different diets (regular or KD) were used. Cardiac function and interstitial fibrosis were determined. T-regulatory cell (Treg) number and functions were evaluated. The effects of ketone body (KB) on fatty acid (FA) and glucose metabolism, mitochondria-associated endoplasmic reticulum membranes (MAMs), and mitochondrial respiration were assessed. The mechanisms via which KB regulated MAMs and Tregs were addressed. KD improved metabolic indices in db/db mice. However, KD impaired cardiac diastolic function and exacerbated ventricular fibrosis. Proportions of circulatory CD4+CD25+Foxp3+ cells in whole blood cells and serum levels of IL-4 and IL-10 were reduced in mice fed with KD. KB suppressed the differentiation to Tregs from naive CD4+ T cells. Cultured medium from KB-treated Tregs synergically activated cardiac fibroblasts. Meanwhile, KB inhibited Treg proliferation and productions of IL-4 and IL-10. Treg MAMs, mitochondrial respiration and respiratory complexes, and FA synthesis and oxidation were all suppressed by KB while glycolytic levels were increased. L-carnitine reversed Treg proliferation and function inhibited by KB. Proportions of ST2L+ cells in Tregs were reduced by KB, as well as the production of ST2L ligand, IL-33. Reinforcement expressions of ST2L in Tregs counteracted the reductions in MAMs, mitochondrial respiration, and Treg proliferations and productions of Treg cytokines IL-4 and IL-10. Therefore, despite the improvement of metabolic indices, KD impaired Treg expansion and function and promoted cardiac fibroblast activation and interstitial fibrosis. This could be mainly mediated by the suppression of MAMs and fatty acid metabolism inhibition via blunting IL-33/ST2L signaling.
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Li Y, Zhang X, Ma A, Kang Y. Rational Application of β-Hydroxybutyrate Attenuates Ischemic Stroke by Suppressing Oxidative Stress and Mitochondrial-Dependent Apoptosis via Activation of the Erk/CREB/eNOS Pathway. ACS Chem Neurosci 2021; 12:1219-1227. [PMID: 33739811 DOI: 10.1021/acschemneuro.1c00046] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Stroke is one of the leading causes of disability and death. Increasing evidence indicates that β-hydroxybutyrate (BHB) exerts beneficial effects in treating stroke, but the underlying mechanism remains largely unknown. In this study, we injected different doses of BHB into the lateral ventricle in middle cerebral artery occlusion (MCAO) model rats and neuronal cells were treated with different doses of BHB followed by oxygen-glucose deprivation (OGD). We found that a moderate dose of BHB enhanced mitochondrial complex I respiratory chain complex I activity, reduced oxidative stress, inhibited mitochondrial apoptosis, improved neurological scores, and reduced infarct volume after ischemia. We further showed that the effects of BHB were achieved by upregulating the dedicated BHB transporter SMCT1 and activating the Erk/CREB/eNOS pathway. These results provide us with a foundation for a novel understanding of the neuroprotective effects of BHB in stroke.
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Affiliation(s)
- Yang Li
- Intensive Care Unit, West China School of Medicine/West China Hospital of Sichuan University, Chengdu, Sichuan 610041, People’s Republic of China
| | - Xuepeng Zhang
- Intensive Care Unit, West China School of Medicine/West China Hospital of Sichuan University, Chengdu, Sichuan 610041, People’s Republic of China
| | - Aijia Ma
- Intensive Care Unit, West China School of Medicine/West China Hospital of Sichuan University, Chengdu, Sichuan 610041, People’s Republic of China
| | - Yan Kang
- Intensive Care Unit, West China School of Medicine/West China Hospital of Sichuan University, Chengdu, Sichuan 610041, People’s Republic of China
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Hinds TD, Creeden JF, Gordon DM, Stec DF, Donald MC, Stec DE. Bilirubin Nanoparticles Reduce Diet-Induced Hepatic Steatosis, Improve Fat Utilization, and Increase Plasma β-Hydroxybutyrate. Front Pharmacol 2020; 11:594574. [PMID: 33390979 PMCID: PMC7775678 DOI: 10.3389/fphar.2020.594574] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Accepted: 11/13/2020] [Indexed: 12/18/2022] Open
Abstract
The inverse relationship of plasma bilirubin levels with liver fat accumulation has prompted the possibility of bilirubin as a therapeutic for non-alcoholic fatty liver disease. Here, we used diet-induced obese mice with non-alcoholic fatty liver disease treated with pegylated bilirubin (bilirubin nanoparticles) or vehicle control to determine the impact on hepatic lipid accumulation. The bilirubin nanoparticles significantly reduced hepatic fat, triglyceride accumulation, de novo lipogenesis, and serum levels of liver dysfunction marker aspartate transaminase and ApoB100 containing very-low-density lipoprotein. The bilirubin nanoparticles improved liver function and activated the hepatic β-oxidation pathway by increasing PPARα and acyl-coenzyme A oxidase 1. The bilirubin nanoparticles also significantly elevated plasma levels of the ketone β-hydroxybutyrate and lowered liver fat accumulation. This study demonstrates that bilirubin nanoparticles induce hepatic fat utilization, raise plasma ketones, and reduce hepatic steatosis, opening new therapeutic avenues for NAFLD.
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Affiliation(s)
- Terry D Hinds
- Department of Pharmacology and Nutritional Sciences, University of Kentucky College of Medicine, Lexington, KY, United States
| | - Justin F Creeden
- Department of Neurosciences, University of Toledo College of Medicine, Toledo, OH, United States
| | - Darren M Gordon
- Department of Neurosciences, University of Toledo College of Medicine, Toledo, OH, United States
| | - Donald F Stec
- Small Molecule NMR Facility Core, Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN, United States
| | - Matthew C Donald
- Department of Physiology and Biophysics, Cardiorenal and Metabolic Diseases Research Center, University of Mississippi Medical Center, Jackson, MS, United States
| | - David E Stec
- Department of Physiology and Biophysics, Cardiorenal and Metabolic Diseases Research Center, University of Mississippi Medical Center, Jackson, MS, United States
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Poffé C, Hespel P. Ketone bodies: beyond their role as a potential energy substrate in exercise. J Physiol 2020; 598:4749-4750. [DOI: 10.1113/jp280597] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Affiliation(s)
- Chiel Poffé
- Exercise Physiology Research Group Department of Movement Sciences KU Leuven Leuven Belgium
| | - Peter Hespel
- Exercise Physiology Research Group Department of Movement Sciences KU Leuven Leuven Belgium
- Bakala Academy‐Athletic Performance Center KU Leuven Leuven Belgium
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Petrick HL, Brunetta HS, Pignanelli C, Nunes EA, van Loon LJC, Burr JF, Holloway GP. In vitro ketone-supported mitochondrial respiration is minimal when other substrates are readily available in cardiac and skeletal muscle. J Physiol 2020; 598:4869-4885. [PMID: 32735362 DOI: 10.1113/jp280032] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 07/28/2020] [Indexed: 12/30/2022] Open
Abstract
KEY POINTS Ketone bodies are proposed to represent an alternative fuel source driving energy production, particularly during exercise. Biologically, the extent to which mitochondria utilize ketone bodies compared to other substrates remains unknown. We demonstrate in vitro that maximal mitochondrial respiration supported by ketone bodies is low when compared to carbohydrate-derived substrates in the left ventricle and red gastrocnemius muscle from rodents, and in human skeletal muscle. When considering intramuscular concentrations of ketone bodies and the presence of other carbohydrate and lipid substrates, biological rates of mitochondrial respiration supported by ketone bodies are predicted to be minimal. At the mitochondrial level, it is therefore unlikely that ketone bodies are an important source for energy production in cardiac and skeletal muscle, particularly when other substrates are readily available. ABSTRACT Ketone bodies (KB) have recently gained popularity as an alternative fuel source to support mitochondrial oxidative phosphorylation and enhance exercise performance. However, given the low activity of ketolytic enzymes and potential inhibition from carbohydrate oxidation, it remains unknown if KBs can contribute to energy production. We therefore determined the ability of KBs (sodium dl-β-hydroxybutyrate, β-HB; lithium acetoacetate, AcAc) to stimulate in vitro mitochondrial respiration in the left ventricle (LV) and red gastrocnemius (RG) of rats, and in human vastus lateralis. Compared to pyruvate, the ability of KBs to maximally drive respiration was low in isolated mitochondria and permeabilized fibres (PmFb) from the LV (∼30-35% of pyruvate), RG (∼10-30%), and human vastus lateralis (∼2-10%). In PmFb, the concentration of KBs required to half-maximally drive respiration (LV: 889 µm β-HB, 801 µm AcAc; RG: 782 µm β-HB, 267 µm AcAc) were greater than KB content representative of the muscle microenvironment (∼100 µm). This would predict low rates (∼1-4% of pyruvate) of biological KB-supported respiration in the LV (8-14 pmol s-1 mg-1 ) and RG (3-6 pmol s-1 mg-1 ) at rest and following exercise. Moreover, KBs did not increase respiration in the presence of saturating pyruvate, submaximal pyruvate (100 µm) reduced the ability of physiological β-HB to drive respiration, and addition of other intracellular substrates (succinate + palmitoylcarnitine) decreased maximal KB-supported respiration. As a result, product inhibition is likely to limit KB oxidation. Altogether, the ability of KBs to drive mitochondrial respiration is minimal and they are likely to be outcompeted by other substrates, compromising their use as an important energy source.
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Affiliation(s)
- Heather L Petrick
- Department of Human Health and Nutritional Science, University of Guelph, Guelph, Ontario, Canada
| | - Henver S Brunetta
- Department of Human Health and Nutritional Science, University of Guelph, Guelph, Ontario, Canada.,Department of Physiological Sciences, Federal University of Santa Catarina, Florianopolis, Santa Catarina, Brazil
| | - Chris Pignanelli
- Department of Human Health and Nutritional Science, University of Guelph, Guelph, Ontario, Canada
| | - Everson A Nunes
- Department of Physiological Sciences, Federal University of Santa Catarina, Florianopolis, Santa Catarina, Brazil.,Department of Kinesiology, McMaster University, Hamilton, Ontario, Canada
| | - Luc J C van Loon
- Department of Human Biology, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Jamie F Burr
- Department of Human Health and Nutritional Science, University of Guelph, Guelph, Ontario, Canada
| | - Graham P Holloway
- Department of Human Health and Nutritional Science, University of Guelph, Guelph, Ontario, Canada
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