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Huang T, Chen X, He J, Zheng P, Luo Y, Wu A, Yan H, Yu B, Chen D, Huang Z. Eugenol mimics exercise to promote skeletal muscle fiber remodeling and myokine IL-15 expression by activating TRPV1 channel. eLife 2024; 12:RP90724. [PMID: 38913071 PMCID: PMC11196110 DOI: 10.7554/elife.90724] [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] [Indexed: 06/25/2024] Open
Abstract
Metabolic disorders are highly prevalent in modern society. Exercise mimetics are defined as pharmacological compounds that can produce the beneficial effects of fitness. Recently, there has been increased interest in the role of eugenol and transient receptor potential vanilloid 1 (TRPV1) in improving metabolic health. The aim of this study was to investigate whether eugenol acts as an exercise mimetic by activating TRPV1. Here, we showed that eugenol improved endurance capacity, caused the conversion of fast-to-slow muscle fibers, and promoted white fat browning and lipolysis in mice. Mechanistically, eugenol promoted muscle fiber-type transformation by activating TRPV1-mediated CaN signaling pathway. Subsequently, we identified IL-15 as a myokine that is regulated by the CaN/nuclear factor of activated T cells cytoplasmic 1 (NFATc1) signaling pathway. Moreover, we found that TRPV1-mediated CaN/NFATc1 signaling, activated by eugenol, controlled IL-15 levels in C2C12 myotubes. Our results suggest that eugenol may act as an exercise mimetic to improve metabolic health via activating the TRPV1-mediated CaN signaling pathway.
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Affiliation(s)
- Tengteng Huang
- Key Laboratory for Animal Disease-Resistance Nutrition of China Ministry of Education, Institute of Animal Nutrition, Sichuan Agricultural UniversityChengduChina
| | - Xiaoling Chen
- Key Laboratory for Animal Disease-Resistance Nutrition of China Ministry of Education, Institute of Animal Nutrition, Sichuan Agricultural UniversityChengduChina
| | - Jun He
- Key Laboratory for Animal Disease-Resistance Nutrition of China Ministry of Education, Institute of Animal Nutrition, Sichuan Agricultural UniversityChengduChina
| | - Ping Zheng
- Key Laboratory for Animal Disease-Resistance Nutrition of China Ministry of Education, Institute of Animal Nutrition, Sichuan Agricultural UniversityChengduChina
| | - Yuheng Luo
- Key Laboratory for Animal Disease-Resistance Nutrition of China Ministry of Education, Institute of Animal Nutrition, Sichuan Agricultural UniversityChengduChina
| | - Aimin Wu
- Key Laboratory for Animal Disease-Resistance Nutrition of China Ministry of Education, Institute of Animal Nutrition, Sichuan Agricultural UniversityChengduChina
| | - Hui Yan
- Key Laboratory for Animal Disease-Resistance Nutrition of China Ministry of Education, Institute of Animal Nutrition, Sichuan Agricultural UniversityChengduChina
| | - Bing Yu
- Key Laboratory for Animal Disease-Resistance Nutrition of China Ministry of Education, Institute of Animal Nutrition, Sichuan Agricultural UniversityChengduChina
| | - Daiwen Chen
- Key Laboratory for Animal Disease-Resistance Nutrition of China Ministry of Education, Institute of Animal Nutrition, Sichuan Agricultural UniversityChengduChina
| | - Zhiqing Huang
- Key Laboratory for Animal Disease-Resistance Nutrition of China Ministry of Education, Institute of Animal Nutrition, Sichuan Agricultural UniversityChengduChina
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2
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Yeudall S, Upchurch CM, Seegren PV, Pavelec CM, Greulich J, Lemke MC, Harris TE, Desai BN, Hoehn KL, Leitinger N. Macrophage acetyl-CoA carboxylase regulates acute inflammation through control of glucose and lipid metabolism. SCIENCE ADVANCES 2022; 8:eabq1984. [PMID: 36417534 PMCID: PMC9683712 DOI: 10.1126/sciadv.abq1984] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2022] [Accepted: 10/27/2022] [Indexed: 05/27/2023]
Abstract
Acetyl-CoA carboxylase (ACC) regulates lipid synthesis; however, its role in inflammatory regulation in macrophages remains unclear. We generated mice that are deficient in both ACC isoforms in myeloid cells. ACC deficiency altered the lipidomic, transcriptomic, and bioenergetic profile of bone marrow-derived macrophages, resulting in a blunted response to proinflammatory stimulation. In response to lipopolysaccharide (LPS), ACC is required for the early metabolic switch to glycolysis and remodeling of the macrophage lipidome. ACC deficiency also resulted in impaired macrophage innate immune functions, including bacterial clearance. Myeloid-specific deletion or pharmacological inhibition of ACC in mice attenuated LPS-induced expression of proinflammatory cytokines interleukin-6 (IL-6) and IL-1β, while pharmacological inhibition of ACC increased susceptibility to bacterial peritonitis in wild-type mice. Together, we identify a critical role for ACC in metabolic regulation of the innate immune response in macrophages, and thus a clinically relevant, unexpected consequence of pharmacological ACC inhibition.
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Affiliation(s)
- Scott Yeudall
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Clint M. Upchurch
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Philip V. Seegren
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Caitlin M. Pavelec
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Jan Greulich
- Environmentally-Induced Cardiovascular Degeneration, Clinical Chemistry and Laboratory Diagnostics, Medical Faculty, University Hospital and Heinrich-Heine University Düsseldorf, 40225 Düsseldorf, Germany
| | - Michael C. Lemke
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Thurl E. Harris
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Bimal N. Desai
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Kyle L. Hoehn
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Norbert Leitinger
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
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3
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Palmer BF, Clegg DJ. Metabolic Flexibility and Its Impact on Health Outcomes. Mayo Clin Proc 2022; 97:761-776. [PMID: 35287953 DOI: 10.1016/j.mayocp.2022.01.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 01/04/2022] [Accepted: 01/12/2022] [Indexed: 02/06/2023]
Abstract
A metabolically flexible state exists when there is a rapid switch between glucose and fatty acids during the transition between the fed and fasting state. This flexibility in fuel choice serves to prevent hyperglycemia following a meal and simultaneously ensures an adequate amount of blood glucose is available for delivery to the brain and exclusively glycolytic tissues during fasting. The modern era is characterized by chronic overnutrition in which a mixture of fuels is delivered to the mitochondria in an unabated manner thereby uncoupling the feast and famine situation. The continuous influx of fuel leads to accumulation of reducing equivalents in the mitochondria and an increase in the mitochondrial membrane potential. These changes create a microenvironment fostering the generation of reactive oxygen species and other metabolites leading to deleterious protein modification, cell injury, and ultimately clinical disease. Insulin resistance may also play a primary role in this deleterious effect. The imbalance between mitochondrial energy delivery and use is made worse with a sedentary lifestyle. Maneuvers that restore energy balance across the mitochondria activate pathways that remove or repair damaged molecules and restore the plasticity characteristic of normal energy metabolism. Readily available strategies to maintain energy balance across the mitochondria include exercise, various forms of caloric restriction, administration of sodium-glucose cotransporter-2 inhibitors, cold exposure, and hypobaric hypoxia.
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Affiliation(s)
- Biff F Palmer
- Department of Medicine, Division of Nephrology, University of Texas Southwestern Medical Center, Dallas, TX, USA.
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4
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Anirudhan T, Mani A, Athira V. Molecularly imprinted electrochemical sensing platform for 2-Aminoadipic acid, a diabetes biomarker. REACT FUNCT POLYM 2021. [DOI: 10.1016/j.reactfunctpolym.2021.105056] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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5
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Worley BL, Auen T, Arnold AC, Monia BP, Hempel N, Czyzyk TA. Antisense oligonucleotide-mediated knockdown of Mpzl3 attenuates the negative metabolic effects of diet-induced obesity in mice. Physiol Rep 2021; 9:e14853. [PMID: 33991450 PMCID: PMC8123547 DOI: 10.14814/phy2.14853] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 04/05/2021] [Indexed: 02/06/2023] Open
Abstract
Previously, we demonstrated that global knockout (KO) of the gene encoding myelin protein zero‐like 3 (Mpzl3) results in reduced body weight and adiposity, increased energy expenditure, and reduced hepatic lipid synthesis in mice. These mice also exhibit cyclic and progressive alopecia which may contribute to the observed hypermetabolic phenotype. The goal of the current study was to determine if acute and peripherally restricted knockdown of Mpzl3 could ameliorate the negative metabolic effects of exposure to a high‐fat and sucrose, energy‐dense (HED) diet similar to what was observed in global Mpzl3 KO mice in the absence of a skin phenotype. Mpzl3 antisense oligonucleotide (ASO) administration dose‐dependently decreased fat mass and circulating lipids in HED‐fed C57BL/6N mice. These changes were accompanied by a decrease in respiratory exchange ratio, a reduction in energy expenditure and food intake, a decrease in expression of genes regulating de novo lipogenesis in white adipose tissue, and an upregulation of genes associated with steroid hormone biosynthesis in liver, thermogenesis in brown adipose tissue and fatty acid transport in skeletal muscle. These data demonstrate that resistance to the negative metabolic effects of HED is a direct effect of Mpzl3 knockdown, rather than compensatory changes that could be associated with deletion of Mpzl3 during development in global KO mice. Inhibiting MPZL3 could be a potential therapeutic approach for the treatment of obesity and associated dyslipidemia.
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Affiliation(s)
- Beth L Worley
- Department of Anesthesiology & Perioperative Medicine, Penn State University College of Medicine, Hershey, PA, USA.,Department of Pharmacology, Penn State University College of Medicine, Hershey, PA, USA.,Biomedical Sciences Program, Penn State University College of Medicine, Hershey, PA, USA
| | - Thomas Auen
- Department of Anesthesiology & Perioperative Medicine, Penn State University College of Medicine, Hershey, PA, USA
| | - Amy C Arnold
- Department of Neural & Behavioral Sciences, Penn State University College of Medicine, Hershey, PA, USA
| | | | - Nadine Hempel
- Department of Pharmacology, Penn State University College of Medicine, Hershey, PA, USA
| | - Traci A Czyzyk
- Department of Anesthesiology & Perioperative Medicine, Penn State University College of Medicine, Hershey, PA, USA.,Department of Neural & Behavioral Sciences, Penn State University College of Medicine, Hershey, PA, USA
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6
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Morigny P, Boucher J, Arner P, Langin D. Lipid and glucose metabolism in white adipocytes: pathways, dysfunction and therapeutics. Nat Rev Endocrinol 2021; 17:276-295. [PMID: 33627836 DOI: 10.1038/s41574-021-00471-8] [Citation(s) in RCA: 185] [Impact Index Per Article: 61.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 01/15/2021] [Indexed: 12/14/2022]
Abstract
In mammals, the white adipocyte is a cell type that is specialized for storage of energy (in the form of triacylglycerols) and for energy mobilization (as fatty acids). White adipocyte metabolism confers an essential role to adipose tissue in whole-body homeostasis. Dysfunction in white adipocyte metabolism is a cardinal event in the development of insulin resistance and associated disorders. This Review focuses on our current understanding of lipid and glucose metabolic pathways in the white adipocyte. We survey recent advances in humans on the importance of adipocyte hypertrophy and on the in vivo turnover of adipocytes and stored lipids. At the molecular level, the identification of novel regulators and of the interplay between metabolic pathways explains the fine-tuning between the anabolic and catabolic fates of fatty acids and glucose in different physiological states. We also examine the metabolic alterations involved in the genesis of obesity-associated metabolic disorders, lipodystrophic states, cancers and cancer-associated cachexia. New challenges include defining the heterogeneity of white adipocytes in different anatomical locations throughout the lifespan and investigating the importance of rhythmic processes. Targeting white fat metabolism offers opportunities for improved patient stratification and a wide, yet unexploited, range of therapeutic opportunities.
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Affiliation(s)
- Pauline Morigny
- Institute of Metabolic and Cardiovascular Diseases (I2MC), Institut National de la Santé et de la Recherche Médicale (Inserm), UMR1297, Toulouse, France
- University of Toulouse, Paul Sabatier University, I2MC, UMR1297, Toulouse, France
- Institute for Diabetes and Cancer, Helmholtz Center Munich, Neuherberg, Germany
- Joint Heidelberg-IDC Translational Diabetes Program, Inner Medicine 1, Heidelberg University Hospital, Heidelberg, Germany
- German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Jeremie Boucher
- Bioscience Metabolism, Research and Early Development, Cardiovascular, Renal and Metabolism (CVRM), BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
- The Lundberg Laboratory for Diabetes Research, University of Gothenburg, Gothenburg, Sweden
- Wallenberg Centre for Molecular and Translational Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Peter Arner
- Department of Medicine (H7), Karolinska Institutet, Stockholm, Sweden
| | - Dominique Langin
- Institute of Metabolic and Cardiovascular Diseases (I2MC), Institut National de la Santé et de la Recherche Médicale (Inserm), UMR1297, Toulouse, France.
- University of Toulouse, Paul Sabatier University, I2MC, UMR1297, Toulouse, France.
- Franco-Czech Laboratory for Clinical Research on Obesity, Third Faculty of Medicine, Prague and Paul Sabatier University, Toulouse, France.
- Toulouse University Hospitals, Laboratory of Clinical Biochemistry, Toulouse, France.
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7
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Smith CD, Lin CT, McMillin SL, Weyrauch LA, Schmidt CA, Smith CA, Kurland IJ, Witczak CA, Neufer PD. Genetically increasing flux through β-oxidation in skeletal muscle increases mitochondrial reductive stress and glucose intolerance. Am J Physiol Endocrinol Metab 2021; 320:E938-E950. [PMID: 33813880 PMCID: PMC8238127 DOI: 10.1152/ajpendo.00010.2021] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Elevated mitochondrial hydrogen peroxide (H2O2) emission and an oxidative shift in cytosolic redox environment have been linked to high-fat-diet-induced insulin resistance in skeletal muscle. To test specifically whether increased flux through mitochondrial fatty acid oxidation, in the absence of elevated energy demand, directly alters mitochondrial function and redox state in muscle, two genetic models characterized by increased muscle β-oxidation flux were studied. In mice overexpressing peroxisome proliferator-activated receptor-α in muscle (MCK-PPARα), lipid-supported mitochondrial respiration, membrane potential (ΔΨm), and H2O2 production rate (JH2O2) were increased, which coincided with a more oxidized cytosolic redox environment, reduced muscle glucose uptake, and whole body glucose intolerance despite an increased rate of energy expenditure. Similar results were observed in lipin-1-deficient, fatty-liver dystrophic mice, another model characterized by increased β-oxidation flux and glucose intolerance. Crossing MCAT (mitochondria-targeted catalase) with MCK-PPARα mice normalized JH2O2 production, redox environment, and glucose tolerance, but surprisingly, both basal and absolute insulin-stimulated rates of glucose uptake in muscle remained depressed. Also surprising, when placed on a high-fat diet, MCK-PPARα mice were characterized by much lower whole body, fat, and lean mass as well as improved glucose tolerance relative to wild-type mice, providing additional evidence that overexpression of PPARα in muscle imposes more extensive metabolic stress than experienced by wild-type mice on a high-fat diet. Overall, the findings suggest that driving an increase in skeletal muscle fatty acid oxidation in the absence of metabolic demand imposes mitochondrial reductive stress and elicits multiple counterbalance metabolic responses in an attempt to restore bioenergetic homeostasis.NEW & NOTEWORTHY Prior work has suggested that mitochondrial dysfunction is an underlying cause of insulin resistance in muscle because it limits fatty acid oxidation and therefore leads to the accumulation of cytotoxic lipid intermediates. The implication has been that therapeutic strategies to accelerate β-oxidation will be protective. The current study provides evidence that genetically increasing flux through β-oxidation in muscle imposes reductive stress that is not beneficial but rather detrimental to metabolic regulation.
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Affiliation(s)
- Cody D Smith
- East Carolina Diabetes and Obesity Institute, Brody School of Medicine, East Carolina University, Greenville, North Carolina
- Department of Physiology, Brody School of Medicine, East Carolina University, Greenville, North Carolina
| | - Chien-Te Lin
- East Carolina Diabetes and Obesity Institute, Brody School of Medicine, East Carolina University, Greenville, North Carolina
- Department of Physiology, Brody School of Medicine, East Carolina University, Greenville, North Carolina
| | - Shawna L McMillin
- East Carolina Diabetes and Obesity Institute, Brody School of Medicine, East Carolina University, Greenville, North Carolina
- Department of Biochemistry & Molecular Biology, Brody School of Medicine, East Carolina University, Greenville, North Carolina
| | - Luke A Weyrauch
- East Carolina Diabetes and Obesity Institute, Brody School of Medicine, East Carolina University, Greenville, North Carolina
- Department of Biochemistry & Molecular Biology, Brody School of Medicine, East Carolina University, Greenville, North Carolina
| | - Cameron A Schmidt
- East Carolina Diabetes and Obesity Institute, Brody School of Medicine, East Carolina University, Greenville, North Carolina
- Department of Physiology, Brody School of Medicine, East Carolina University, Greenville, North Carolina
| | - Cheryl A Smith
- East Carolina Diabetes and Obesity Institute, Brody School of Medicine, East Carolina University, Greenville, North Carolina
- Department of Physiology, Brody School of Medicine, East Carolina University, Greenville, North Carolina
| | - Irwin J Kurland
- Department of Medicine, Albert Einstein College of Medicine, Bronx, New York
| | - Carol A Witczak
- East Carolina Diabetes and Obesity Institute, Brody School of Medicine, East Carolina University, Greenville, North Carolina
- Department of Physiology, Brody School of Medicine, East Carolina University, Greenville, North Carolina
- Department of Biochemistry & Molecular Biology, Brody School of Medicine, East Carolina University, Greenville, North Carolina
- Department of Kinesiology, East Carolina University, Greenville, North Carolina
| | - P Darrell Neufer
- East Carolina Diabetes and Obesity Institute, Brody School of Medicine, East Carolina University, Greenville, North Carolina
- Department of Physiology, Brody School of Medicine, East Carolina University, Greenville, North Carolina
- Department of Biochemistry & Molecular Biology, Brody School of Medicine, East Carolina University, Greenville, North Carolina
- Department of Kinesiology, East Carolina University, Greenville, North Carolina
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8
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Presby DM, Rudolph MC, Sherk VD, Jackman MR, Foright RM, Jones KL, Houck JA, Johnson GC, Higgins JA, Neufer PD, Eckel RH, MacLean PS. Lipoprotein Lipase Overexpression in Skeletal Muscle Attenuates Weight Regain by Potentiating Energy Expenditure. Diabetes 2021; 70:867-877. [PMID: 33536195 PMCID: PMC7980196 DOI: 10.2337/db20-0763] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Accepted: 01/27/2021] [Indexed: 11/13/2022]
Abstract
Moderate weight loss improves numerous risk factors for cardiometabolic disease; however, long-term weight loss maintenance (WLM) is often thwarted by metabolic adaptations that suppress energy expenditure and facilitate weight regain. Skeletal muscle has a prominent role in energy homeostasis; therefore, we investigated the effect of WLM and weight regain on skeletal muscle in rodents. In skeletal muscle of obesity-prone rats, WLM reduced fat oxidative capacity and downregulated genes involved in fat metabolism. Interestingly, even after weight was regained, genes involved in fat metabolism were also reduced. We then subjected mice with skeletal muscle lipoprotein lipase overexpression (mCK-hLPL), which augments fat metabolism, to WLM and weight regain and found that mCK-hLPL attenuates weight regain by potentiating energy expenditure. Irrespective of genotype, weight regain suppressed dietary fat oxidation and downregulated genes involved in fat metabolism in skeletal muscle. However, mCK-hLPL mice oxidized more fat throughout weight regain and had greater expression of genes involved in fat metabolism and lower expression of genes involved in carbohydrate metabolism during WLM and regain. In summary, these results suggest that skeletal muscle fat oxidation is reduced during WLM and regain, and therapies that improve skeletal muscle fat metabolism may attenuate rapid weight regain.
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Affiliation(s)
- David M Presby
- Section on Integrative Physiology and Metabolism, Joslin Diabetes Center, Harvard Medical School, Boston, MA
| | - Michael C Rudolph
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK
| | - Vanessa D Sherk
- Division of Endocrinology, Metabolism and Diabetes, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO
| | - Matthew R Jackman
- Section on Integrative Physiology and Metabolism, Joslin Diabetes Center, Harvard Medical School, Boston, MA
| | - Rebecca M Foright
- Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, KS
| | - Kenneth L Jones
- Department of Pediatrics, University of Colorado Denver Anschutz Medical Campus, Aurora, CO
| | - Julie A Houck
- Division of Endocrinology, Metabolism and Diabetes, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO
| | - Ginger C Johnson
- Division of Endocrinology, Metabolism and Diabetes, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO
| | - Janine A Higgins
- Department of Pediatrics, University of Colorado Denver Anschutz Medical Campus, Aurora, CO
| | - P Darrell Neufer
- East Carolina Diabetes and Obesity Institute and the Department of Physiology, Brody School of Medicine, East Carolina University, Greenville, NC
| | - Robert H Eckel
- Division of Endocrinology, Metabolism and Diabetes, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO
| | - Paul S MacLean
- Division of Endocrinology, Metabolism and Diabetes, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO
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9
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Nagarajan SR, Butler LM, Hoy AJ. The diversity and breadth of cancer cell fatty acid metabolism. Cancer Metab 2021; 9:2. [PMID: 33413672 PMCID: PMC7791669 DOI: 10.1186/s40170-020-00237-2] [Citation(s) in RCA: 92] [Impact Index Per Article: 30.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Accepted: 12/16/2020] [Indexed: 12/13/2022] Open
Abstract
Tumor cellular metabolism exhibits distinguishing features that collectively enhance biomass synthesis while maintaining redox balance and cellular homeostasis. These attributes reflect the complex interactions between cell-intrinsic factors such as genomic-transcriptomic regulation and cell-extrinsic influences, including growth factor and nutrient availability. Alongside glucose and amino acid metabolism, fatty acid metabolism supports tumorigenesis and disease progression through a range of processes including membrane biosynthesis, energy storage and production, and generation of signaling intermediates. Here, we highlight the complexity of cellular fatty acid metabolism in cancer, the various inputs and outputs of the intracellular free fatty acid pool, and the numerous ways that these pathways influence disease behavior.
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Affiliation(s)
- Shilpa R Nagarajan
- Discipline of Physiology, School of Medical Sciences, Charles Perkins Centre, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia.,Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Churchill Hospital, Oxford, UK
| | - Lisa M Butler
- Adelaide Medical School and Freemasons Foundation Centre for Men's Health, University of Adelaide, Adelaide, SA, Australia.,South Australian Health and Medical Research Institute, Adelaide, SA, Australia
| | - Andrew J Hoy
- Discipline of Physiology, School of Medical Sciences, Charles Perkins Centre, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia.
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10
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Genders AJ, Holloway GP, Bishop DJ. Are Alterations in Skeletal Muscle Mitochondria a Cause or Consequence of Insulin Resistance? Int J Mol Sci 2020; 21:ijms21186948. [PMID: 32971810 PMCID: PMC7554894 DOI: 10.3390/ijms21186948] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Revised: 09/18/2020] [Accepted: 09/18/2020] [Indexed: 12/14/2022] Open
Abstract
As a major site of glucose uptake following a meal, skeletal muscle has an important role in whole-body glucose metabolism. Evidence in humans and animal models of insulin resistance and type 2 diabetes suggests that alterations in mitochondrial characteristics accompany the development of skeletal muscle insulin resistance. However, it is unclear whether changes in mitochondrial content, respiratory function, or substrate oxidation are central to the development of insulin resistance or occur in response to insulin resistance. Thus, this review will aim to evaluate the apparent conflicting information placing mitochondria as a key organelle in the development of insulin resistance in skeletal muscle.
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Affiliation(s)
- Amanda J. Genders
- Institute for Health and Sport (iHeS), Victoria University, Melbourne 8001, Australia;
- Correspondence: ; Tel.: +61-3-9919-9556
| | - Graham P. Holloway
- Dept. Human Health and Nutritional Sciences, University of Guelph, Guelph, ON N1G 2W1, Canada;
| | - David J. Bishop
- Institute for Health and Sport (iHeS), Victoria University, Melbourne 8001, Australia;
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11
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Liu T, Gou L, Yan S, Huang T. Inhibition of acetyl-CoA carboxylase by PP-7a exerts beneficial effects on metabolic dysregulation in a mouse model of diet-induced obesity. Exp Ther Med 2020; 20:521-529. [PMID: 32550887 PMCID: PMC7296295 DOI: 10.3892/etm.2020.8700] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Accepted: 03/18/2020] [Indexed: 12/14/2022] Open
Abstract
Acetyl-coenzyme A carboxylase (ACC) is a critical regulator of fatty acid metabolism and represents a promising therapeutic target for metabolic diseases, including obesity, type 2 diabetes and non-alcoholic fatty liver disease. Recently, a novel ACC inhibitor, PP-7a, was developed by our group by utilizing a structure-based drug design. In the present study, the pharmacological effects of PP-7a on the metabolic dysregulation in mice with high-fat diet (HFD)-induced obesity and the underlying mechanisms were investigated. The inhibitory effect on ACC activities was confirmed by assessing the level of malonyl-CoA, a product synthesized by the catalyzation of ACC. Following 16 weeks of being fed an HFD, the mice were administered PP-7a (15, 45 or 75 mg/kg) for 4 weeks. The effects of PP-7a on weight gain, glucose intolerance, hepatic lipid accumulation and the increase of serum triglyceride (TG), total cholesterol (TC) and free fatty acids (FFA) in mice were assessed. CP-640186 was used as a positive control drug and administered in the same manner as PP-7a. Chronic administration of PP-7a lowered the malonyl-CoA levels in liver and heart tissues of mice in the HFD group. In addition, HFD-induced weight gain and glucose intolerance were improved by PP-7a treatment in the mice fed the HFD. Furthermore, PP-7a suppressed hepatic lipid accumulation and the increase in TG, TC and FFA levels. Taken together, these results suggest that ACC inhibition by PP-7a may have a beneficial effect on metabolic dysregulation in obese mice.
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Affiliation(s)
- Tianya Liu
- Department of Pharmacy, The Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu 221004, P.R. China
- Jiangsu Province Key Laboratory of Anesthesiology, School of Anesthesiology, Xuzhou Medical University, Xuzhou, Jiangsu 221004, P.R. China
| | - Lingshan Gou
- Center for Genetic Medicine, Maternity and Child Health Care Hospital Affiliated to Xuzhou Medical University, Xuzhou, Jiangsu 221004, P.R. China
| | - Shirong Yan
- Jiangsu Province Key Laboratory of New Drug Research and Clinical Pharmacy, School of Pharmacy, Xuzhou Medical University, Xuzhou, Jiangsu 221004, P.R. China
| | - Tonghui Huang
- Jiangsu Province Key Laboratory of New Drug Research and Clinical Pharmacy, School of Pharmacy, Xuzhou Medical University, Xuzhou, Jiangsu 221004, P.R. China
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12
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Ross TT, Crowley C, Kelly KL, Rinaldi A, Beebe DA, Lech MP, Martinez RV, Carvajal-Gonzalez S, Boucher M, Hirenallur-Shanthappa D, Morin J, Opsahl AC, Vargas SR, Bence KK, Pfefferkorn JA, Esler WP. Acetyl-CoA Carboxylase Inhibition Improves Multiple Dimensions of NASH Pathogenesis in Model Systems. Cell Mol Gastroenterol Hepatol 2020; 10:829-851. [PMID: 32526482 PMCID: PMC7509217 DOI: 10.1016/j.jcmgh.2020.06.001] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Revised: 06/01/2020] [Accepted: 06/02/2020] [Indexed: 12/12/2022]
Abstract
BACKGROUND & AIMS Disordered metabolism, steatosis, hepatic inflammation, and fibrosis contribute to the pathogenesis of nonalcoholic steatohepatitis (NASH). Acetyl-CoA carboxylase (ACC) catalyzes the first committed step in de novo lipogenesis (DNL) and modulates mitochondrial fatty acid oxidation. Increased hepatic DNL flux and reduced fatty acid oxidation are hypothesized to contribute to steatosis. Some proinflammatory cells also show increased dependency on DNL, suggesting that ACC may regulate aspects of the inflammatory response in NASH. PF-05221304 is an orally bioavailable, liver-directed ACC1/2 inhibitor. The present studies sought to evaluate the effects of PF-05221304 on NASH pathogenic factors in experimental model systems. METHODS The effects of PF-05221304 on lipid metabolism, steatosis, inflammation, and fibrogenesis were investigated in both primary human-derived in vitro systems and in vivo rodent models. RESULTS PF-05221304 inhibited DNL, stimulated fatty acid oxidation, and reduced triglyceride accumulation in primary human hepatocytes, and reduced DNL and steatosis in Western diet-fed rats in vivo, showing the potential to reduce hepatic lipid accumulation and potentially lipotoxicity. PF-05221304 blocked polarization of human T cells to proinflammatory but not anti-inflammatory T cells, and suppressed activation of primary human stellate cells to myofibroblasts in vitro, showing direct effects on inflammation and fibrogenesis. Consistent with these observations, PF-05221304 also reduced markers of inflammation and fibrosis in the diethylnitrosamine chemical-induced liver injury model and the choline-deficient, high-fat-fed rat model. CONCLUSIONS The liver-directed dual ACC1/ACC2 inhibitor directly improved multiple nonalcoholic fatty liver disease/NASH pathogenic factors including steatosis, inflammation, and fibrosis in both human-derived in vitro systems and rat models.
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Affiliation(s)
- Trenton T Ross
- Internal Medicine Research Unit, Pfizer Worldwide Research and Development, Cambridge Massachusetts
| | - Collin Crowley
- Internal Medicine Research Unit, Pfizer Worldwide Research and Development, Cambridge Massachusetts
| | - Kenneth L Kelly
- Internal Medicine Research Unit, Pfizer Worldwide Research and Development, Cambridge Massachusetts
| | - Anthony Rinaldi
- Internal Medicine Research Unit, Pfizer Worldwide Research and Development, Cambridge Massachusetts
| | - David A Beebe
- Internal Medicine Research Unit, Pfizer Worldwide Research and Development, Cambridge Massachusetts
| | - Matthew P Lech
- Inflammation and Immunology Research Unit, Pfizer Worldwide Research and Development, Cambridge Massachusetts
| | - Robert V Martinez
- Inflammation and Immunology Research Unit, Pfizer Worldwide Research and Development, Cambridge Massachusetts
| | | | - Magalie Boucher
- Drug Safety Research and Development, Pfizer Worldwide Research and Development, Cambridge Massachusetts
| | | | - Jeffrey Morin
- Comparative Medicine, Pfizer Worldwide Research and Development, Cambridge Massachusetts
| | - Alan C Opsahl
- Drug Safety Research and Development, Pfizer Worldwide Research and Development, Cambridge Massachusetts
| | - Sarah R Vargas
- Drug Safety Research and Development, Pfizer Worldwide Research and Development, Cambridge Massachusetts
| | - Kendra K Bence
- Internal Medicine Research Unit, Pfizer Worldwide Research and Development, Cambridge Massachusetts
| | - Jeffrey A Pfefferkorn
- Internal Medicine Research Unit, Pfizer Worldwide Research and Development, Cambridge Massachusetts
| | - William P Esler
- Internal Medicine Research Unit, Pfizer Worldwide Research and Development, Cambridge Massachusetts.
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13
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Abstract
Competing theories have held opposite views on the role of flux through β-oxidation in causing insulin resistance. New transcriptomics, proteomics, and metabolomics data of skeletal muscle from mice in which lipid oxidation is limited by restricting entry of fat into mitochondria reveal extensive remodeling of metabolic pathways, consistent with an overall reduction in metabolic efficiency and improved metabolic health. These findings point to a potential new therapeutic approach for treating insulin resistance and type 2 diabetes.
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Affiliation(s)
- P Darrell Neufer
- East Carolina Diabetes and Obesity Institute and Department of Physiology, Brody School of Medicine, East Carolina University, Greenville, North Carolina 27834.
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14
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Chen Q, Ji C, Zheng R, Yang L, Ren J, Li Y, Han Y, Zhou P, Liu Z, Qiu Y. N-Palmitoylethanolamine Maintains Local Lipid Homeostasis to Relieve Sleep Deprivation-Induced Dry Eye Syndrome. Front Pharmacol 2020; 10:1622. [PMID: 32047441 PMCID: PMC6997544 DOI: 10.3389/fphar.2019.01622] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 12/13/2019] [Indexed: 11/13/2022] Open
Abstract
Sleep loss is a key factor associated with dry eye. Use of a “stick over water” mouse model revealed that sleep deprivation induces accumulation of lipids, hypertrophy, and dysfunction of the lacrimal gland. These changes result in decreased tear production and dry eye clinical signs. The specific pathophysiological mechanisms that contribute to dry eye remain unclear. In this study, we found that sleep deprivation decreased endogenous lipid palmitoylethanolamide (PEA) expression in the lacrimal gland. The reduced expression was mainly attributed to the decreased expression of N-acylated phosphatidylethanolamine–phospholipase D, the synthetic enzyme of PEA. Exogenous PEA treatment restored local lipid metabolism homeostasis in the lacrimal gland. This change was accompanied by reduced lipid deposition, maintenance of the endoplasmic reticulum and mitochondrial morphology, and improved acinar cell secretory function. PEA treatment also prevented damage to corneal barrier function and improved the dry eye clinical signs caused by sleep deprivation. The nuclear receptor peroxisome proliferator-activated receptor-α (PPAR-α) was found to mediate the PEA-associated improvements. We describe here for the first time that PEA is involved in sleep deprivation–induced lacrimal gland pathogenesis and dry eye development. PEA and its metabolizing enzymes may serve as adjunctive therapeutic targets for treatment of dry eye.
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Affiliation(s)
- Qi Chen
- Eye Institute of Xiamen University, Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, School of Medicine, Xiamen University, Xiamen, China.,Department of Ophthalmology, Xiang'an Hospital of Xiamen University, Xiamen, China.,Xiamen University Affiliated Xiamen Eye Center, Xiamen, China
| | - Chunyan Ji
- Eye Institute of Xiamen University, Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, School of Medicine, Xiamen University, Xiamen, China.,Department of Ophthalmology, Xiang'an Hospital of Xiamen University, Xiamen, China
| | - Ruihe Zheng
- Eye Institute of Xiamen University, Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, School of Medicine, Xiamen University, Xiamen, China.,Department of Ophthalmology, Xiang'an Hospital of Xiamen University, Xiamen, China
| | - Longhe Yang
- Engineering Research Center of Marine Biological Resource Comprehensive Utilization, Third Institute of Oceanography, State Oceanic Administration, Xiamen, China
| | - Jie Ren
- Eye Institute of Xiamen University, Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, School of Medicine, Xiamen University, Xiamen, China.,Department of Ophthalmology, Xiang'an Hospital of Xiamen University, Xiamen, China
| | - Yitian Li
- Eye Institute of Xiamen University, Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, School of Medicine, Xiamen University, Xiamen, China.,Department of Ophthalmology, Xiang'an Hospital of Xiamen University, Xiamen, China
| | - Yun Han
- Eye Institute of Xiamen University, Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, School of Medicine, Xiamen University, Xiamen, China.,Department of Ophthalmology, Xiang'an Hospital of Xiamen University, Xiamen, China.,Xiamen University Affiliated Xiamen Eye Center, Xiamen, China
| | - Pan Zhou
- Eye Institute of Xiamen University, Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, School of Medicine, Xiamen University, Xiamen, China.,Department of Ophthalmology, Xiang'an Hospital of Xiamen University, Xiamen, China
| | - Zuguo Liu
- Eye Institute of Xiamen University, Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, School of Medicine, Xiamen University, Xiamen, China.,Department of Ophthalmology, Xiang'an Hospital of Xiamen University, Xiamen, China.,Xiamen University Affiliated Xiamen Eye Center, Xiamen, China
| | - Yan Qiu
- Eye Institute of Xiamen University, Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, School of Medicine, Xiamen University, Xiamen, China.,Department of Ophthalmology, Xiang'an Hospital of Xiamen University, Xiamen, China.,Xiamen University Affiliated Xiamen Eye Center, Xiamen, China
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15
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Recent development in acetyl-CoA carboxylase inhibitors and their potential as novel drugs. Future Med Chem 2020; 12:533-561. [PMID: 32048880 DOI: 10.4155/fmc-2019-0312] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Acetyl-CoA carboxylase (ACC), a critical enzyme in the regulation of fatty acid synthesis and metabolism, has emerged as an attractive target for a plethora of emerging diseases, such as diabetes mellitus, nonalcoholic fatty liver disease, cancer, bacterial infections and so on. With decades of efforts in medicinal chemistry, significant progress has been made toward the design and discovery of a considerable number of inhibitors of this enzyme. In this review, we not only clarify the role of ACC in emerging diseases, but also summarize recent developments of potent ACC inhibitors and discuss their molecular mechanisms of action and potentials as novel drugs as well as future perspectives toward the design and discovery of novel ACC inhibitors.
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16
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Takagi H, Tanimoto K, Shimazaki A, Tonomura Y, Momosaki S, Sakamoto S, Abe K, Notoya M, Yukioka H. A Novel Acetyl-CoA Carboxylase 2 Selective Inhibitor Improves Whole-Body Insulin Resistance and Hyperglycemia in Diabetic Mice through Target-Dependent Pathways. J Pharmacol Exp Ther 2020; 372:256-263. [DOI: 10.1124/jpet.119.263590] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Accepted: 12/31/2019] [Indexed: 01/23/2023] Open
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17
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Song K, Zhang Y, Ga Q, Bai Z, Ge RL. Increased Insulin Sensitivity by High-Altitude Hypoxia in Mice with High-Fat Diet-Induced Obesity Is Associated with Activated AMPK Signaling and Subsequently Enhanced Mitochondrial Biogenesis in Skeletal Muscles. Obes Facts 2020; 13:455-472. [PMID: 32966981 PMCID: PMC7670386 DOI: 10.1159/000508112] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Accepted: 04/20/2020] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND This study aimed to investigate whether and how high altitude-associated ambient hypoxia affects insulin sensitivity in mice fed a high-fat diet (HFD). METHODS Mice were randomly divided into a control group (with normal diet feeding and low-altitude housing), LA/HFD group (with HFD feeding and low-altitude housing), and HA/HFD group (with HFD feeding and high-altitude housing). RESULTS After 8 weeks, mice in the HA/HFD group showed improved insulin sensitivity-related indices compared with the LA/HFD group. In mice residing in a low-altitude region, HFD significantly impaired mitochondrial respiratory function and mitochondrial DNA content in skeletal muscles, which was partially reversed in mice in the HA/HFD group. In addition, the fatty acid oxidation-related enzyme gene CPT1 (carnitine palmitoyltransferase 1) and genes related to mitochondrial biogenesis such as peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α), nuclear respiratory factor 1 (NRF1), and mitochondrial transcription factor A (Tfam) were upregulated in the skeletal muscles of mice housed at high altitude, in comparison to in the LA/HFD group. Furthermore, AMPK (adenosine monophosphate-activated protein kinase) signaling was activated in the skeletal muscles, as evidenced by a higher expression of phosphorylated AMPK (p-AMPK) and protein kinase B (p-AKT) in the HA/HFD group than in the LA/HFD group. CONCLUSION Our study suggests that high-altitude hypoxia improves insulin sensitivity in mice fed an HFD, which is associated with AMPK activation in the skeletal muscle and consequently enhanced mitochondrial biogenesis and fatty acid oxidation. This work provides a molecular explanation for why high altitude is associated with a reduced incidence of insulin resistance in the obese population.
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Affiliation(s)
- Kang Song
- Research Center for High Altitude Medicine, Qinghai University Medical College, Xining, China,
- Key Laboratory for Application of High Altitude Medicine in Qinghai Province, Xining, China,
- Department of Endocrinology, Qinghai Provincial People's Hospital, Xining, China,
| | - Yifan Zhang
- Research Center for High Altitude Medicine, Qinghai University Medical College, Xining, China
- Key Laboratory for Application of High Altitude Medicine in Qinghai Province, Xining, China
| | - Qin Ga
- Research Center for High Altitude Medicine, Qinghai University Medical College, Xining, China
- Key Laboratory for Application of High Altitude Medicine in Qinghai Province, Xining, China
| | - Zhenzhong Bai
- Research Center for High Altitude Medicine, Qinghai University Medical College, Xining, China
- Key Laboratory for Application of High Altitude Medicine in Qinghai Province, Xining, China
| | - Ri-Li Ge
- Research Center for High Altitude Medicine, Qinghai University Medical College, Xining, China
- Key Laboratory for Application of High Altitude Medicine in Qinghai Province, Xining, China
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18
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Lu Z, He XF, Ma BB, Zhang L, Li JL, Jiang Y, Zhou GH, Gao F. Increased fat synthesis and limited apolipoprotein B cause lipid accumulation in the liver of broiler chickens exposed to chronic heat stress. Poult Sci 2019; 98:3695-3704. [PMID: 30809677 DOI: 10.3382/ps/pez056] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Accepted: 01/26/2019] [Indexed: 12/28/2022] Open
Abstract
Chronic heat stress can enhance fat synthesis in broilers, and excessive triglyceride (TG) synthesized by the liver needs to be transported to extrahepatic tissues by very low density lipoprotein (VLDL) otherwise will accumulate in the liver, which may even result in hepatic steatosis. To investigate the molecular mechanisms by which chronic heat stress enhances fat synthesis and results in lipid accumulation in the liver of chickens, 144 broilers (Arbor Acres, 28-day-old) were randomly allocated to the normal control (NC, 22°C), heat stress (HS, consistent 32°C), or pair-fed (PF, 22°C) groups for a 14-D trial. The 7 D of heat exposure significantly increased the respiratory rate, relative weight of abdominal fat, the levels of glucose, TG, corticosterone, insulin, and VLDL in plasma, as well as the levels of TG, total cholesterol, acyl-CoA carboxylase (ACC), and fatty acid synthase (FAS) in the liver, and mRNA expression levels of carbohydrate response element-binding protein (ChREBP), ACC, FAS, and microsomal triglyceride transfer protein (MTTP) in comparison with the other 2 groups. After 14 D of heat exposure, the relative weights of abdominal fat and liver and levels of TG and FAS in the liver were significantly higher in the HS group than in the other 2 groups, and there were no significant differences in the respiratory rate, plasma corticosterone concentration, apolipoprotein B (ApoB) level in the liver, and mRNA expression levels of key genes of fat synthesis among the 3 groups. In conclusion, chronic heat exposure activated LXRα pathway and enhanced fat synthesis in the liver after 7 D of heat exposure. After 14 D of heat exposure, heat-stressed broilers exhibited an adaptation to the high temperature in parameters of stress and fat synthesis gene expression levels. Moreover, chronic heat stress resulted in lipid accumulation in the liver of broilers, which is probably because the limited ApoB was not enough to transport the excessive TG synthesized by the liver in chronic heat-stressed broilers.
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Affiliation(s)
- Z Lu
- College of Animal Science and Technology; Jiangsu Key Laboratory of Animal Origin Food Production and Safety Guarantee; Jiangsu Collaborative Innovation Center of Meat Production and Processing, Quality and Safety Control, Nanjing Agricultural University, Nanjing 210095, China
| | - X F He
- College of Animal Science and Technology; Jiangsu Key Laboratory of Animal Origin Food Production and Safety Guarantee; Jiangsu Collaborative Innovation Center of Meat Production and Processing, Quality and Safety Control, Nanjing Agricultural University, Nanjing 210095, China
| | - B B Ma
- College of Animal Science and Technology; Jiangsu Key Laboratory of Animal Origin Food Production and Safety Guarantee; Jiangsu Collaborative Innovation Center of Meat Production and Processing, Quality and Safety Control, Nanjing Agricultural University, Nanjing 210095, China
| | - L Zhang
- College of Animal Science and Technology; Jiangsu Key Laboratory of Animal Origin Food Production and Safety Guarantee; Jiangsu Collaborative Innovation Center of Meat Production and Processing, Quality and Safety Control, Nanjing Agricultural University, Nanjing 210095, China
| | - J L Li
- College of Animal Science and Technology; Jiangsu Key Laboratory of Animal Origin Food Production and Safety Guarantee; Jiangsu Collaborative Innovation Center of Meat Production and Processing, Quality and Safety Control, Nanjing Agricultural University, Nanjing 210095, China
| | - Y Jiang
- Ginling College, Nanjing Normal University, Nanjing 210097, China
| | - G H Zhou
- College of Animal Science and Technology; Jiangsu Key Laboratory of Animal Origin Food Production and Safety Guarantee; Jiangsu Collaborative Innovation Center of Meat Production and Processing, Quality and Safety Control, Nanjing Agricultural University, Nanjing 210095, China
| | - F Gao
- College of Animal Science and Technology; Jiangsu Key Laboratory of Animal Origin Food Production and Safety Guarantee; Jiangsu Collaborative Innovation Center of Meat Production and Processing, Quality and Safety Control, Nanjing Agricultural University, Nanjing 210095, China
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19
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Péronnet F, Haman F. Low capacity to oxidize fat and body weight. Obes Rev 2019; 20:1367-1383. [PMID: 31353786 DOI: 10.1111/obr.12910] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 06/09/2019] [Accepted: 06/10/2019] [Indexed: 12/16/2022]
Abstract
For a given positive energy balance, a low capacity to oxidize fat could contribute to weight gain (low fat oxidation hypothesis). This hypothesis is based on the arguments that for a given stable diet and food quotient (FQ), the respiratory quotient (RQ) is higher in obesity prone (OP) than in obesity resistant individuals (OR) and that a high RQ predicts higher future weight gain. A review of 42 studies shows that there is no convincing experimental support to these arguments and thus for the low fat oxidation hypothesis. A power analysis also shows that this hypothesis might be impossible to experimentally confirm because very large numbers of subjects would be needed to reject the null hypotheses that the 24-h RQ is not different in OP and OR or that future weight gain is not different in individuals with a low and high 24-h RQ at baseline. A re-examination of the significance of the 24-hour and fasting RQ also shows that the assumption underlying the low fat oxidation hypothesis that a high RQ reflects a low capacity to oxidize fat is not valid: For a stable diet, the 24-h RQ entirely depends on FQ and energy balance, and the fasting RQ mainly depends on the FQ and energy balance and on the size of glycogen stores.
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Affiliation(s)
- François Péronnet
- École de kinésiologie et des sciences de l'activité physique, Faculté de Médecine, Université de Montréal, Montréal, QC, Canada
| | - François Haman
- École des sciences de l'activité physique, Faculté des sciences de la santé, Université d'Ottawa, Ottawa, ON, Canada
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20
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2-Aminoadipic acid (2-AAA) as a potential biomarker for insulin resistance in childhood obesity. Sci Rep 2019; 9:13610. [PMID: 31541119 PMCID: PMC6754510 DOI: 10.1038/s41598-019-49578-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Accepted: 08/23/2019] [Indexed: 01/09/2023] Open
Abstract
Insulin resistance is an important clinical feature of metabolic syndrome, which includes obesity and type 2 diabetes. Increased adipose energy storage in obesity promote insulin resistance and other metabolic adverse effects. To identify a new link between adipocyte and insulin resistance, we performed targeted metabolite profiling of differentiated adipocytes and studied the association between adipogenic metabolites and insulin resistance. We found a correlation between 2-aminoadipic acid (2-AAA) and adipogenic differentiation. Also, circulatory 2-AAA was positively associated with obesity-related factors (fat mass, fat percent, waist circumference, BMI, BMI z-score, triglycerides, insulin, and HOMA-IR) at baseline and after 2 years in the children cohort study. Of these factors, increased BMI z-score and HOMA-IR were the primary independent factors associated with higher 2-AAA levels, and the baseline 2-AAA level was an indicator of the BMI z-score after 2 years. To validate the relationship between 2-AAA and obesity-related factors, we analyzed changes in 2-AAA levels following obesity intervention programs in two independent studies. In both studies, changes in 2-AAA levels during the intervention period were positively correlated with changes in the BMI z-score and HOMA-IR after adjusting for confounders. Moreover, the 2-AAA levels were increased in cell and mouse models of obesity-related insulin resistance. Excess 2-AAA levels led to impaired insulin signaling in insulin-sensitive cells (liver, skeletal muscle and adipose cells) and caused abnormal gluconeogenesis. Our results demonstrate that 2-AAA is associated with adipogenesis and insulin resistance. In this regard, 2-AAA could be a potential biomarker of obesity and obesity-related metabolic disorders.
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21
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Alkhouri N, Lawitz E, Noureddin M, DeFronzo R, Shulman GI. GS-0976 (Firsocostat): an investigational liver-directed acetyl-CoA carboxylase (ACC) inhibitor for the treatment of non-alcoholic steatohepatitis (NASH). Expert Opin Investig Drugs 2019; 29:135-141. [PMID: 31519114 DOI: 10.1080/13543784.2020.1668374] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Introduction: De novo lipogenesis (DNL) plays a major role in fatty acid metabolism and contributes significantly to triglyceride accumulation within the hepatocytes in patients with nonalcoholic steatohepatitis (NASH). Acetyl-CoA carboxylase (ACC) converts acetyl-CoA to malonyl CoA and is a rate-controlling step in DNL. Furthermore, malonyl-CoA is an important regulator of hepatic mitochondrial fat oxidation through its ability to inhibit carnitine palmitoyltransferase I. Therefore, inhibiting ACC pharmacologically represents an attractive approach to treating NASH.Areas covered: This article summarizes preclinical and clinical data on the efficacy and safety of the liver-targeted ACC inhibitor GS-0976 (Firsocostat) for the treatment of NASH. In a phase 2 trial that included 126 patients with NASH and fibrosis, GS-0976 20 mg daily for 12 weeks showed significant relative reduction in liver fat by 29%; however, treatment was associated with an increase in plasma triglycerides with 16 patients having levels >500 mg/dL.Expert opinion: Preclinical and preliminary clinical data support the development of GS-0976 as treatment for NASH. ACC-induced hypertriglyceridemia can be mitigated by fish oil or fibrates, but the long-term cardiovascular effects require further investigations.
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Affiliation(s)
- Naim Alkhouri
- University of Texas (UT) Health San Antonio, San Antonio, TX, USA.,Texas Liver Institute, San Antonio, TX, USA
| | - Eric Lawitz
- University of Texas (UT) Health San Antonio, San Antonio, TX, USA.,Texas Liver Institute, San Antonio, TX, USA
| | | | - Ralph DeFronzo
- University of Texas (UT) Health San Antonio, San Antonio, TX, USA.,Texas Diabetes Institute (TDI), San Antonio, TX, USA
| | - Gerald I Shulman
- Departments of Internal Medicine and Cellular & Molecular Physiology, Yale School of Medicine, New Haven, CT, USA
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22
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Gu L, Larson Casey JL, Andrabi SA, Lee JH, Meza-Perez S, Randall TD, Carter AB. Mitochondrial calcium uniporter regulates PGC-1α expression to mediate metabolic reprogramming in pulmonary fibrosis. Redox Biol 2019; 26:101307. [PMID: 31473487 PMCID: PMC6831865 DOI: 10.1016/j.redox.2019.101307] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 08/19/2019] [Accepted: 08/20/2019] [Indexed: 12/20/2022] Open
Abstract
Idiopathic pulmonary fibrosis (IPF) is a progressive disease with an increased mortality. Metabolic reprogramming has a critical role in multiple chronic diseases. Lung macrophages expressing the mitochondrial calcium uniporter (MCU) have a critical role in fibrotic repair, but the contribution of MCU in macrophage metabolism is not known. Here, we show that MCU regulates peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) and metabolic reprogramming to fatty acid oxidation (FAO) in macrophages. MCU regulated PGC-1α expression by increasing the phosphorylation of ATF-2 by the p38 MAPK in a redox-dependent manner. The expression and activation of PGC-1α via the p38 MAPK was regulated by MCU-mediated mitochondrial calcium uptake, which is linked to increased mitochondrial ROS (mtROS) production. Mice harboring a conditional expression of dominant-negative MCU in macrophages had a marked reduction in mtROS and FAO and were protected from pulmonary fibrosis. Moreover, IPF lung macrophages had evidence of increased MCU and mitochondrial calcium, increased phosphorylation of ATF2 and p38, as well as increased expression of PGC-1α. These observations suggest that macrophage MCU-mediated metabolic reprogramming contributes to fibrotic repair after lung injury.
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Affiliation(s)
- Linlin Gu
- Department of Medicine, Division of Pulmonary, Allergy and Critical Care Medicine, University of Alabama at Birmingham, Birmingham, AL, 35294, USA
| | - Jennifer L Larson Casey
- Department of Medicine, Division of Pulmonary, Allergy and Critical Care Medicine, University of Alabama at Birmingham, Birmingham, AL, 35294, USA
| | - Shaida A Andrabi
- Department of Pharmacology & Toxicology, University of Alabama at Birmingham, Birmingham, AL, 35294, USA
| | - Jun Hee Lee
- Department of Pharmacology & Toxicology, University of Alabama at Birmingham, Birmingham, AL, 35294, USA
| | - Selene Meza-Perez
- Department of Medicine, Division of Clinical Immunology and Rheumatology, University of Alabama at Birmingham, Birmingham, AL, 35294, USA
| | - Troy D Randall
- Department of Medicine, Division of Clinical Immunology and Rheumatology, University of Alabama at Birmingham, Birmingham, AL, 35294, USA
| | - A Brent Carter
- Department of Medicine, Division of Pulmonary, Allergy and Critical Care Medicine, University of Alabama at Birmingham, Birmingham, AL, 35294, USA; Birmingham VAMC, Birmingham, AL, 35294, USA.
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23
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Jiménez de Oya N, Esler WP, Huard K, El-Kattan AF, Karamanlidis G, Blázquez AB, Ramos-Ibeas P, Escribano-Romero E, Louloudes-Lázaro A, Casas J, Sobrino F, Hoehn K, James DE, Gutiérrez-Adán A, Saiz JC, Martín-Acebes MA. Targeting host metabolism by inhibition of acetyl-Coenzyme A carboxylase reduces flavivirus infection in mouse models. Emerg Microbes Infect 2019; 8:624-636. [PMID: 30999821 PMCID: PMC6493301 DOI: 10.1080/22221751.2019.1604084] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Flaviviruses are (re)-emerging RNA viruses strictly dependent on lipid metabolism for infection. In the search for host targeting antivirals, we explored the effect of pharmacological modulation of fatty acid metabolism during flavivirus infection. Considering the central role of acetyl-Coenzyme A carboxylase (ACC) on fatty acid metabolism, we analyzed the effect of three small-molecule ACC inhibitors (PF-05175157, PF-05206574, and PF-06256254) on the infection of medically relevant flaviviruses, namely West Nile virus (WNV), dengue virus, and Zika virus. Treatment with these compounds inhibited the multiplication of the three viruses in cultured cells. PF-05175157 induced a reduction of the viral load in serum and kidney in WNV-infected mice, unveiling its therapeutic potential for the treatment of chronic kidney disease associated with persistent WNV infection. This study constitutes a proof of concept of the reliability of ACC inhibitors to become viable antiviral candidates. These results support the repositioning of metabolic inhibitors as broad-spectrum antivirals.
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Affiliation(s)
- Nereida Jiménez de Oya
- a Department of Biotechnology , Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA) , Madrid , Spain
| | - William P Esler
- b Worldwide Research and Development Pfizer , Cambridge , MA , USA
| | - Kim Huard
- b Worldwide Research and Development Pfizer , Cambridge , MA , USA
| | | | - Georgios Karamanlidis
- b Worldwide Research and Development Pfizer , Cambridge , MA , USA.,h Present address: Cardiometabolic Disorders Amgen Discovery Research , Thousand Oaks , California 91320 , USA
| | - Ana-Belén Blázquez
- a Department of Biotechnology , Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA) , Madrid , Spain
| | | | - Estela Escribano-Romero
- a Department of Biotechnology , Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA) , Madrid , Spain
| | - Andrés Louloudes-Lázaro
- a Department of Biotechnology , Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA) , Madrid , Spain
| | - Josefina Casas
- d Department of Biomedicinal Chemistry , Institute for Advanced Chemistry of Catalonia (IQAC-CSIC) and CIBEREHD , Barcelona , Spain
| | - Francisco Sobrino
- e Department of Virology and Microbiology , Centro de Biología Molecular "Severo Ochoa" (CSIC-UAM) , Madrid , Spain
| | - Kyle Hoehn
- f School of Biotechnology and Biomolecular Sciences , University of New South Wales , Sydney , Australia
| | - David E James
- g Charles Perkins Centre, School of Life and Environmental Sciences, Sydney Medical School , University of Sydney , Australia
| | | | - Juan-Carlos Saiz
- a Department of Biotechnology , Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA) , Madrid , Spain
| | - Miguel A Martín-Acebes
- a Department of Biotechnology , Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA) , Madrid , Spain
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Naini A, Sasse F, Brönstrup M. The intriguing chemistry and biology of soraphens. Nat Prod Rep 2019; 36:1394-1411. [PMID: 30950477 DOI: 10.1039/c9np00008a] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Covering: up to the end of 2018Soraphens are a class of polyketide natural products discovered from the myxobacterial strain Sorangium cellulosum. The review is intended to provide an overview on the biosynthesis, chemistry and biological properties of soraphens, that represent a prime example to showcase the value of natural products as tools to decipher cell biology, but also to open novel therapeutic options. The prototype soraphen A is an inhibitor of acetyl coenzyme A carboxylase (ACC1/2), an enzyme that converts acetyl-CoA to malonyl-CoA and thereby controls essential cellular metabolic processes like lipogenesis and fatty acid oxidation. Soraphens illustrate how the inhibition of a single target (ACC1/2) may be explored to treat various pathological conditions: initially developed as a fungicide, efforts in the past decade were directed towards human diseases, including diabetes/obesity, cancer, hepatitis C, HIV, and autoimmune disease - and led to a synthetic molecule, discovered by virtual screening of the allosteric binding site of soraphen in ACC, that is currently in phase 2 clinical trials. We will summarize how structural analogs of soraphen A have been generated through extensive isolation efforts, genetic engineering of the biosynthetic gene cluster, semisynthesis as well as partial and total synthesis.
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Affiliation(s)
- Arun Naini
- Department of Chemical Biology, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany. and Center of Biomolecular Drug Research (BMWZ), Leibniz University, 30159 Hannover, Germany
| | - Florenz Sasse
- Center of Biomolecular Drug Research (BMWZ), Leibniz University, 30159 Hannover, Germany
| | - Mark Brönstrup
- Department of Chemical Biology, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany. and Center of Biomolecular Drug Research (BMWZ), Leibniz University, 30159 Hannover, Germany and German Center for Infection Research (DZIF), Partner Site Hannover-Braunschweig, Germany
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Bowman CE, Wolfgang MJ. Role of the malonyl-CoA synthetase ACSF3 in mitochondrial metabolism. Adv Biol Regul 2019; 71:34-40. [PMID: 30201289 PMCID: PMC6347522 DOI: 10.1016/j.jbior.2018.09.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Revised: 09/04/2018] [Accepted: 09/04/2018] [Indexed: 12/26/2022]
Abstract
Malonyl-CoA is a central metabolite in fatty acid biochemistry. It is the rate-determining intermediate in fatty acid synthesis but is also an allosteric inhibitor of the rate-setting step in mitochondrial long-chain fatty acid oxidation. While these canonical cytoplasmic roles of malonyl-CoA have been well described, malonyl-CoA can also be generated within the mitochondrial matrix by an alternative pathway: the ATP-dependent ligation of malonate to Coenzyme A by the malonyl-CoA synthetase ACSF3. Malonate, a competitive inhibitor of succinate dehydrogenase of the TCA cycle, is a potent inhibitor of mitochondrial respiration. A major role for ACSF3 is to provide a metabolic pathway for the clearance of malonate by the generation of malonyl-CoA, which can then be decarboxylated to acetyl-CoA by malonyl-CoA decarboxylase. Additionally, ACSF3-derived malonyl-CoA can be used to malonylate lysine residues on proteins within the matrix of mitochondria, possibly adding another regulatory layer to post-translational control of mitochondrial metabolism. The discovery of ACSF3-mediated generation of malonyl-CoA defines a new mitochondrial metabolic pathway and raises new questions about how the metabolic fates of this multifunctional metabolite intersect with mitochondrial metabolism.
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Affiliation(s)
- Caitlyn E Bowman
- Department of Biological Chemistry, The Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Michael J Wolfgang
- Department of Biological Chemistry, The Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA.
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Petersen MC, Shulman GI. Mechanisms of Insulin Action and Insulin Resistance. Physiol Rev 2018; 98:2133-2223. [PMID: 30067154 PMCID: PMC6170977 DOI: 10.1152/physrev.00063.2017] [Citation(s) in RCA: 1382] [Impact Index Per Article: 230.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Revised: 03/22/2018] [Accepted: 03/24/2018] [Indexed: 12/15/2022] Open
Abstract
The 1921 discovery of insulin was a Big Bang from which a vast and expanding universe of research into insulin action and resistance has issued. In the intervening century, some discoveries have matured, coalescing into solid and fertile ground for clinical application; others remain incompletely investigated and scientifically controversial. Here, we attempt to synthesize this work to guide further mechanistic investigation and to inform the development of novel therapies for type 2 diabetes (T2D). The rational development of such therapies necessitates detailed knowledge of one of the key pathophysiological processes involved in T2D: insulin resistance. Understanding insulin resistance, in turn, requires knowledge of normal insulin action. In this review, both the physiology of insulin action and the pathophysiology of insulin resistance are described, focusing on three key insulin target tissues: skeletal muscle, liver, and white adipose tissue. We aim to develop an integrated physiological perspective, placing the intricate signaling effectors that carry out the cell-autonomous response to insulin in the context of the tissue-specific functions that generate the coordinated organismal response. First, in section II, the effectors and effects of direct, cell-autonomous insulin action in muscle, liver, and white adipose tissue are reviewed, beginning at the insulin receptor and working downstream. Section III considers the critical and underappreciated role of tissue crosstalk in whole body insulin action, especially the essential interaction between adipose lipolysis and hepatic gluconeogenesis. The pathophysiology of insulin resistance is then described in section IV. Special attention is given to which signaling pathways and functions become insulin resistant in the setting of chronic overnutrition, and an alternative explanation for the phenomenon of ‟selective hepatic insulin resistanceˮ is presented. Sections V, VI, and VII critically examine the evidence for and against several putative mediators of insulin resistance. Section V reviews work linking the bioactive lipids diacylglycerol, ceramide, and acylcarnitine to insulin resistance; section VI considers the impact of nutrient stresses in the endoplasmic reticulum and mitochondria on insulin resistance; and section VII discusses non-cell autonomous factors proposed to induce insulin resistance, including inflammatory mediators, branched-chain amino acids, adipokines, and hepatokines. Finally, in section VIII, we propose an integrated model of insulin resistance that links these mediators to final common pathways of metabolite-driven gluconeogenesis and ectopic lipid accumulation.
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Affiliation(s)
- Max C Petersen
- Departments of Internal Medicine and Cellular & Molecular Physiology, Howard Hughes Medical Institute, Yale University School of Medicine , New Haven, Connecticut
| | - Gerald I Shulman
- Departments of Internal Medicine and Cellular & Molecular Physiology, Howard Hughes Medical Institute, Yale University School of Medicine , New Haven, Connecticut
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A selective inhibitor of ceramide synthase 1 reveals a novel role in fat metabolism. Nat Commun 2018; 9:3165. [PMID: 30131496 PMCID: PMC6104039 DOI: 10.1038/s41467-018-05613-7] [Citation(s) in RCA: 87] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Accepted: 07/17/2018] [Indexed: 02/06/2023] Open
Abstract
Specific forms of the lipid ceramide, synthesized by the ceramide synthase enzyme family, are believed to regulate metabolic physiology. Genetic mouse models have established C16 ceramide as a driver of insulin resistance in liver and adipose tissue. C18 ceramide, synthesized by ceramide synthase 1 (CerS1), is abundant in skeletal muscle and suggested to promote insulin resistance in humans. We herein describe the first isoform-specific ceramide synthase inhibitor, P053, which inhibits CerS1 with nanomolar potency. Lipidomic profiling shows that P053 is highly selective for CerS1. Daily P053 administration to mice fed a high-fat diet (HFD) increases fatty acid oxidation in skeletal muscle and impedes increases in muscle triglycerides and adiposity, but does not protect against HFD-induced insulin resistance. Our inhibitor therefore allowed us to define a role for CerS1 as an endogenous inhibitor of mitochondrial fatty acid oxidation in muscle and regulator of whole-body adiposity. Ceramides are signalling molecules that regulate several physiological functions including insulin sensitivity. Here the authors report a selective ceramide synthase 1 inhibitor that counteracts lipid accumulation within the muscle and adiposity by increasing fatty acid oxidation but without affecting insulin sensitivity in mice fed with an obesogenic diet.
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Takagi H, Ikehara T, Kashiwagi Y, Hashimoto K, Nanchi I, Shimazaki A, Nambu H, Yukioka H. ACC2 Deletion Enhances IMCL Reduction Along With Acetyl-CoA Metabolism and Improves Insulin Sensitivity in Male Mice. Endocrinology 2018; 159:3007-3019. [PMID: 29931154 DOI: 10.1210/en.2018-00338] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Accepted: 06/15/2018] [Indexed: 12/13/2022]
Abstract
Intramyocellular lipid (IMCL) accumulation in skeletal muscle greatly contributes to lipid-induced insulin resistance. Because acetyl-coenzyme A (CoA) carboxylase (ACC) 2 negatively modulates mitochondrial fatty acid oxidation (FAO) in skeletal muscle, ACC2 inhibition is expected to reduce IMCL via elevation of FAO and to attenuate insulin resistance. However, the concept of substrate competition suggests that enhanced FAO results in reduced glucose use because of an excessive acetyl-CoA pool in mitochondria. To identify how ACC2-regulated FAO affects IMCL accumulation and glucose metabolism, we generated ACC2 knockout (ACC2-/-) mice and investigated skeletal muscle metabolites associated with fatty acid and glucose metabolism, as well as whole-body glucose metabolism. ACC2-/- mice displayed higher capacity of glucose disposal at the whole-body levels. In skeletal muscle, ACC2-/- mice exhibited enhanced acylcarnitine formation and reduced IMCL levels without alteration in glycolytic intermediate levels. Notably, these changes were accompanied by decreased acetyl-CoA content and enhanced mitochondrial pathways related to acetyl-CoA metabolism, such as the acetylcarnitine production and tricarboxylic acid cycle. Furthermore, ACC2-/- mice exhibited lower levels of IMCL and acetyl-CoA even under HFD conditions and showed protection against HFD-induced insulin resistance. Our findings suggest that ACC2 deletion leads to IMCL reduction without suppressing glucose use via an elevation in acetyl-CoA metabolism even under HFD conditions and offer new mechanistic insight into the therapeutic potential of ACC2 inhibition on insulin resistance.
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Affiliation(s)
- Hiroyuki Takagi
- Drug Discovery and Disease Research Laboratory, Shionogi & Co., Ltd., Osaka, Japan
| | - Tatsuya Ikehara
- Biomarker Research and Development Department, Shionogi & Co., Ltd., Osaka, Japan
| | - Yuto Kashiwagi
- Biomarker Research and Development Department, Shionogi & Co., Ltd., Osaka, Japan
| | - Kumi Hashimoto
- Drug Discovery and Disease Research Laboratory, Shionogi & Co., Ltd., Osaka, Japan
| | - Isamu Nanchi
- Drug Discovery and Disease Research Laboratory, Shionogi & Co., Ltd., Osaka, Japan
| | - Atsuyuki Shimazaki
- Drug Discovery and Disease Research Laboratory, Shionogi & Co., Ltd., Osaka, Japan
| | - Hirohide Nambu
- Drug Discovery and Disease Research Laboratory, Shionogi & Co., Ltd., Osaka, Japan
| | - Hideo Yukioka
- Drug Discovery and Disease Research Laboratory, Shionogi & Co., Ltd., Osaka, Japan
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de Ligt M, Bruls YMH, Hansen J, Habets MF, Havekes B, Nascimento EBM, Moonen-Kornips E, Schaart G, Schrauwen-Hinderling VB, van Marken Lichtenbelt W, Schrauwen P. Resveratrol improves ex vivo mitochondrial function but does not affect insulin sensitivity or brown adipose tissue in first degree relatives of patients with type 2 diabetes. Mol Metab 2018; 12:39-47. [PMID: 29706321 PMCID: PMC6001939 DOI: 10.1016/j.molmet.2018.04.004] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Revised: 03/27/2018] [Accepted: 04/06/2018] [Indexed: 01/01/2023] Open
Abstract
Objective Resveratrol supplementation improves metabolic health in healthy obese men, but not in patients with type 2 diabetes (T2D) when given as add-on therapy. Therefore, we examined whether resveratrol can enhance metabolic health in men at risk of developing T2D. Additionally, we examined if resveratrol can stimulate brown adipose tissue (BAT). Methods Thirteen male first degree relatives (FDR) of patients with T2D received resveratrol (150 mg/day) and placebo for 30 days in a randomized, placebo controlled, cross-over trial. Results Resveratrol significantly improved ex vivo muscle mitochondrial function on a fatty acid-derived substrate. However, resveratrol did not improve insulin sensitivity, expressed as the rate of glucose disposal during a two-step hyperinsulinemic-euglycemic clamp. Also, intrahepatic and intramyocellular lipid content, substrate utilization, energy metabolism, and cold-stimulated 18F-FDG glucose uptake in BAT (n = 8) remained unaffected by resveratrol. In vitro experiments in adipocytes derived from human BAT confirmed the lack of effect on BAT. Conclusions Resveratrol stimulates muscle mitochondrial function in FDR males, which is in concordance with previous results. However, no other metabolic benefits of resveratrol were found in this group. This could be attributed to subject characteristics causing alterations in metabolism of resveratrol and thereby affecting resveratrol's effectiveness. ClinicalTrials.gov ID NCT02129595. Resveratrol supplementation improves muscle mitochondrial function. Resveratrol does not improve insulin sensitivity in people at risk of diabetes. Resveratrol does not affect brown adipose tissue in people at risk of diabetes.
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Affiliation(s)
- Marlies de Ligt
- Department of Nutrition and Movement Sciences, Maastricht Medical Centre, NUTRIM School of Nutrition and Translational Research in Metabolism, The Netherlands
| | - Yvonne M H Bruls
- Department of Nutrition and Movement Sciences, Maastricht Medical Centre, NUTRIM School of Nutrition and Translational Research in Metabolism, The Netherlands; Department of Radiology, Maastricht University Medical Centre, NUTRIM School for Nutrition and Translational Research in Metabolism, The Netherlands
| | - Jan Hansen
- Department of Nutrition and Movement Sciences, Maastricht Medical Centre, NUTRIM School of Nutrition and Translational Research in Metabolism, The Netherlands
| | - Marie-Fleur Habets
- Department of Nutrition and Movement Sciences, Maastricht Medical Centre, NUTRIM School of Nutrition and Translational Research in Metabolism, The Netherlands
| | - Bas Havekes
- Department of Internal Medicine, Division of Endocrinology, Maastricht University Medical Centre, The Netherlands
| | - Emmani B M Nascimento
- Department of Nutrition and Movement Sciences, Maastricht Medical Centre, NUTRIM School of Nutrition and Translational Research in Metabolism, The Netherlands
| | - Esther Moonen-Kornips
- Department of Nutrition and Movement Sciences, Maastricht Medical Centre, NUTRIM School of Nutrition and Translational Research in Metabolism, The Netherlands
| | - Gert Schaart
- Department of Nutrition and Movement Sciences, Maastricht Medical Centre, NUTRIM School of Nutrition and Translational Research in Metabolism, The Netherlands
| | - Vera B Schrauwen-Hinderling
- Department of Nutrition and Movement Sciences, Maastricht Medical Centre, NUTRIM School of Nutrition and Translational Research in Metabolism, The Netherlands; Department of Radiology, Maastricht University Medical Centre, NUTRIM School for Nutrition and Translational Research in Metabolism, The Netherlands
| | - Wouter van Marken Lichtenbelt
- Department of Nutrition and Movement Sciences, Maastricht Medical Centre, NUTRIM School of Nutrition and Translational Research in Metabolism, The Netherlands
| | - Patrick Schrauwen
- Department of Nutrition and Movement Sciences, Maastricht Medical Centre, NUTRIM School of Nutrition and Translational Research in Metabolism, The Netherlands.
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Lu Z, He X, Ma B, Zhang L, Li J, Jiang Y, Zhou G, Gao F. Chronic Heat Stress Impairs the Quality of Breast-Muscle Meat in Broilers by Affecting Redox Status and Energy-Substance Metabolism. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2017; 65:11251-11258. [PMID: 29212325 DOI: 10.1021/acs.jafc.7b04428] [Citation(s) in RCA: 112] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We investigated the molecular mechanisms by which chronic heat stress impairs the breast-meat quality of broilers. Broilers were assigned to three groups: the normal control (NC) group, heat-stress (HS) group, and pair-fed (PF) group. After 7 days of heat exposure (32 °C), the high temperature had caused oxidative stress; elevated the activity of citrate synthase (CS), the mRNA expression of M-CPT1, and the phosphorylation level of AMPKα; and reduced the mRNA expression of avUCP. After 14 days of heat exposure, the heat stress had increased the lightness and drip loss and decreased the pH and shear force of the breast meat. Additionally, the heat exposure had increased the mRNA expressions of FAS, ACC, and PDK4; the content of lipids; and the activities of lactic dehydrogenase and pyruvate kinase, and it had decreased the mRNA expression of M-CPT1 and the activity of CS. In conclusion, chronic heat stress impairs meat quality by causing mitochondria to malfunction and affecting energy-substance aerobic metabolism, resulting in increased glycolysis and intramuscular fat deposition.
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Affiliation(s)
- Zhuang Lu
- College of Animal Science and Technology, Key Laboratory of Animal Origin Food Production and Safety Guarantee of Jiangsu Province, Jiangsu Collaborative Innovation Center of Meat Production and Processing, Quality and Safety Control, Nanjing Agricultural University , Nanjing 210095, P.R. China
| | - Xiaofang He
- College of Animal Science and Technology, Key Laboratory of Animal Origin Food Production and Safety Guarantee of Jiangsu Province, Jiangsu Collaborative Innovation Center of Meat Production and Processing, Quality and Safety Control, Nanjing Agricultural University , Nanjing 210095, P.R. China
| | - Bingbing Ma
- College of Animal Science and Technology, Key Laboratory of Animal Origin Food Production and Safety Guarantee of Jiangsu Province, Jiangsu Collaborative Innovation Center of Meat Production and Processing, Quality and Safety Control, Nanjing Agricultural University , Nanjing 210095, P.R. China
| | - Lin Zhang
- College of Animal Science and Technology, Key Laboratory of Animal Origin Food Production and Safety Guarantee of Jiangsu Province, Jiangsu Collaborative Innovation Center of Meat Production and Processing, Quality and Safety Control, Nanjing Agricultural University , Nanjing 210095, P.R. China
| | - Jiaolong Li
- College of Animal Science and Technology, Key Laboratory of Animal Origin Food Production and Safety Guarantee of Jiangsu Province, Jiangsu Collaborative Innovation Center of Meat Production and Processing, Quality and Safety Control, Nanjing Agricultural University , Nanjing 210095, P.R. China
| | - Yun Jiang
- Ginling College, Nanjing Normal University , Nanjing 210097, P.R. China
| | - Guanghong Zhou
- College of Animal Science and Technology, Key Laboratory of Animal Origin Food Production and Safety Guarantee of Jiangsu Province, Jiangsu Collaborative Innovation Center of Meat Production and Processing, Quality and Safety Control, Nanjing Agricultural University , Nanjing 210095, P.R. China
| | - Feng Gao
- College of Animal Science and Technology, Key Laboratory of Animal Origin Food Production and Safety Guarantee of Jiangsu Province, Jiangsu Collaborative Innovation Center of Meat Production and Processing, Quality and Safety Control, Nanjing Agricultural University , Nanjing 210095, P.R. China
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Stöckli J, Fisher-Wellman KH, Chaudhuri R, Zeng XY, Fazakerley DJ, Meoli CC, Thomas KC, Hoffman NJ, Mangiafico SP, Xirouchaki CE, Yang CH, Ilkayeva O, Wong K, Cooney GJ, Andrikopoulos S, Muoio DM, James DE. Metabolomic analysis of insulin resistance across different mouse strains and diets. J Biol Chem 2017; 292:19135-19145. [PMID: 28982973 DOI: 10.1074/jbc.m117.818351] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Indexed: 01/16/2023] Open
Abstract
Insulin resistance is a major risk factor for many diseases. However, its underlying mechanism remains unclear in part because it is triggered by a complex relationship between multiple factors, including genes and the environment. Here, we used metabolomics combined with computational methods to identify factors that classified insulin resistance across individual mice derived from three different mouse strains fed two different diets. Three inbred ILSXISS strains were fed high-fat or chow diets and subjected to metabolic phenotyping and metabolomics analysis of skeletal muscle. There was significant metabolic heterogeneity between strains, diets, and individual animals. Distinct metabolites were changed with insulin resistance, diet, and between strains. Computational analysis revealed 113 metabolites that were correlated with metabolic phenotypes. Using these 113 metabolites, combined with machine learning to segregate mice based on insulin sensitivity, we identified C22:1-CoA, C2-carnitine, and C16-ceramide as the best classifiers. Strikingly, when these three metabolites were combined into one signature, they classified mice based on insulin sensitivity more accurately than each metabolite on its own or other published metabolic signatures. Furthermore, C22:1-CoA was 2.3-fold higher in insulin-resistant mice and correlated significantly with insulin resistance. We have identified a metabolomic signature composed of three functionally unrelated metabolites that accurately predicts whole-body insulin sensitivity across three mouse strains. These data indicate the power of simultaneous analysis of individual, genetic, and environmental variance in mice for identifying novel factors that accurately predict metabolic phenotypes like whole-body insulin sensitivity.
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Affiliation(s)
- Jacqueline Stöckli
- From the Charles Perkins Centre, School of Life and Environmental Sciences, the University of Sydney, Sydney NSW 2006, Australia
| | - Kelsey H Fisher-Wellman
- the Garvan Institute of Medical Research, Sydney NSW 2010, Australia.,the Duke Molecular Physiology Institute, Duke University, Durham, North Carolina 27708
| | - Rima Chaudhuri
- From the Charles Perkins Centre, School of Life and Environmental Sciences, the University of Sydney, Sydney NSW 2006, Australia
| | - Xiao-Yi Zeng
- From the Charles Perkins Centre, School of Life and Environmental Sciences, the University of Sydney, Sydney NSW 2006, Australia
| | - Daniel J Fazakerley
- From the Charles Perkins Centre, School of Life and Environmental Sciences, the University of Sydney, Sydney NSW 2006, Australia
| | | | - Kristen C Thomas
- From the Charles Perkins Centre, School of Life and Environmental Sciences, the University of Sydney, Sydney NSW 2006, Australia
| | - Nolan J Hoffman
- From the Charles Perkins Centre, School of Life and Environmental Sciences, the University of Sydney, Sydney NSW 2006, Australia
| | | | | | - Chieh-Hsin Yang
- the Department of Medicine, University of Melbourne, Melbourne VIC 3010, Australia, and
| | - Olga Ilkayeva
- the Duke Molecular Physiology Institute, Duke University, Durham, North Carolina 27708
| | - Kari Wong
- the Duke Molecular Physiology Institute, Duke University, Durham, North Carolina 27708
| | - Gregory J Cooney
- the Sydney Medical School, the University of Sydney, Sydney NSW 2006, Australia
| | | | - Deborah M Muoio
- the Duke Molecular Physiology Institute, Duke University, Durham, North Carolina 27708
| | - David E James
- From the Charles Perkins Centre, School of Life and Environmental Sciences, the University of Sydney, Sydney NSW 2006, Australia, .,the Sydney Medical School, the University of Sydney, Sydney NSW 2006, Australia
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Tse MCL, Herlea-Pana O, Brobst D, Yang X, Wood J, Hu X, Liu Z, Lee CW, Zaw AM, Chow BKC, Ye K, Chan CB. Tumor Necrosis Factor-α Promotes Phosphoinositide 3-Kinase Enhancer A and AMP-Activated Protein Kinase Interaction to Suppress Lipid Oxidation in Skeletal Muscle. Diabetes 2017; 66:1858-1870. [PMID: 28404596 PMCID: PMC5482076 DOI: 10.2337/db16-0270] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Accepted: 03/29/2017] [Indexed: 12/12/2022]
Abstract
Tumor necrosis factor-α (TNF-α) is an inflammatory cytokine that plays a central role in obesity-induced insulin resistance. It also controls cellular lipid metabolism, but the underlining mechanism is poorly understood. We report in this study that phosphoinositide 3-kinase enhancer A (PIKE-A) is a novel effector of TNF-α to facilitate its metabolic modulation in the skeletal muscle. Depletion of PIKE-A in C2C12 myotubes diminished the inhibitory activities of TNF-α on mitochondrial respiration and lipid oxidation, whereas PIKE-A overexpression exacerbated these cellular responses. We also found that TNF-α promoted the interaction between PIKE-A and AMP-activated protein kinase (AMPK) to suppress its kinase activity in vitro and in vivo. As a result, animals with PIKE ablation in the skeletal muscle per se display an upregulation of AMPK phosphorylation and a higher preference to use lipid as the energy production substrate under high-fat diet feeding, which mitigates the development of diet-induced hyperlipidemia, ectopic lipid accumulation, and muscle insulin resistance. Hence, our data reveal PIKE-A as a new signaling factor that is important for TNF-α-initiated metabolic changes in skeletal muscle.
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Affiliation(s)
- Margaret Chui Ling Tse
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong SAR, People's Republic of China
| | - Oana Herlea-Pana
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK
| | - Daniel Brobst
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK
| | - Xiuying Yang
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK
- Drug Screening Center, Institute of Materia Medica, Beijing, People's Republic of China
| | - John Wood
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK
| | - Xiang Hu
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK
| | - Zhixue Liu
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK
| | - Chi Wai Lee
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong SAR, People's Republic of China
| | - Aung Moe Zaw
- School of Biological Sciences, The University of Hong Kong, Hong Kong SAR, People's Republic of China
| | - Billy K C Chow
- School of Biological Sciences, The University of Hong Kong, Hong Kong SAR, People's Republic of China
| | - Keqiang Ye
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA
| | - Chi Bun Chan
- School of Biological Sciences, The University of Hong Kong, Hong Kong SAR, People's Republic of China
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Protectin DX ameliorates palmitate- or high-fat diet-induced insulin resistance and inflammation through an AMPK-PPARα-dependent pathway in mice. Sci Rep 2017; 7:1397. [PMID: 28469249 PMCID: PMC5431091 DOI: 10.1038/s41598-017-01603-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Accepted: 04/04/2017] [Indexed: 02/06/2023] Open
Abstract
Protectin DX (PDX), a double lipoxygenase derivative of docosahexaenoic acid, has been reported to attenuate inflammation and insulin resistance. In the current study, we explored the effects of PDX on hyperlipidemia-induced insulin resistance and inflammation through AMP-activated protein kinase (AMPK) and peroxisome proliferator-activated receptor α (PPARα). PDX attenuated the impairment of insulin receptor substrate 1/Akt-mediated insulin signaling in palmitate-treated differentiated C2C12 cells and soleus skeletal muscle of HFD-fed mice. Furthermore, PDX treatment significantly ameliorated HFD-induced weight gain and improved glucose tolerance in mice. Nuclear factor kB nuclear translocation, inhibitory kBα phosphorylation, and expression of proinflammatory cytokines were markedly attenuated by PDX in both in vitro and in vivo models. PDX treatment markedly augmented AMPK phosphorylation and PPARα expression in C2C12 cells and in skeletal muscle of mice. AMPK- and PPARα-specific siRNAs significantly abrogated the suppressive effects of PDX on palmitate-induced insulin resistance and inflammation. Furthermore, PDX markedly stimulated the expression of genes related to fatty acid oxidation. These effects of PDX were significantly suppressed by AMPK and PPARα siRNAs. In conclusion, our results demonstrate that PDX ameliorates insulin resistance and inflammation and stimulates fatty acid oxidation through AMPK- and PPARα-mediated pathways in skeletal muscle.
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Abel R, Mondal S, Masse C, Greenwood J, Harriman G, Ashwell MA, Bhat S, Wester R, Frye L, Kapeller R, Friesner RA. Accelerating drug discovery through tight integration of expert molecular design and predictive scoring. Curr Opin Struct Biol 2017; 43:38-44. [DOI: 10.1016/j.sbi.2016.10.007] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Accepted: 10/07/2016] [Indexed: 01/08/2023]
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Spahis S, Borys JM, Levy E. Metabolic Syndrome as a Multifaceted Risk Factor for Oxidative Stress. Antioxid Redox Signal 2017; 26:445-461. [PMID: 27302002 DOI: 10.1089/ars.2016.6756] [Citation(s) in RCA: 81] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
SIGNIFICANCE Metabolic syndrome (MetS) is associated with a greater risk of diabetes and cardiovascular diseases. It is estimated that this multifactorial condition affects 20%-30% of the world's population. A detailed understanding of MetS mechanisms is crucial for the development of effective prevention strategies and adequate intervention tools that could curb its increasing prevalence and limit its comorbidities, particularly in younger age groups. With advances in basic redox biology, oxidative stress (OxS) involvement in the complex pathophysiology of MetS has become widely accepted. Nevertheless, its clear association with and causative effects on MetS require further elucidation. Recent Advances: Although a better understanding of the causes, risks, and effects of MetS is essential, studies suggest that oxidant/antioxidant imbalance is a key contributor to this condition. OxS is now understood to be a major underlying mechanism for mitochondrial dysfunction, ectopic lipid accumulation, and gut microbiota impairment. CRITICAL ISSUES Further studies, particularly in the field of translational research, are clearly required to understand and control the production of reactive oxygen species (ROS) levels, especially in the mitochondria, since the various therapeutic trials conducted to date have not targeted this major ROS-generating system, aimed to delay MetS onset, or prevent its progression. FUTURE DIRECTIONS Multiple relevant markers need to be identified to clarify the role of ROS in the etiology of MetS. Future clinical trials should provide important proof of concept for the effectiveness of antioxidants as useful therapeutic approaches to simultaneously counteract mitochondrial OxS, alleviate MetS symptoms, and prevent complications. Antioxid. Redox Signal. 26, 445-461.
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Affiliation(s)
- Schohraya Spahis
- 1 Research Center , Ste-Justine MUHC, Montreal, Canada .,2 Department of Nutrition, Université de Montréal , Montreal, Canada
| | | | - Emile Levy
- 1 Research Center , Ste-Justine MUHC, Montreal, Canada .,2 Department of Nutrition, Université de Montréal , Montreal, Canada .,3 EPODE International Network , Paris, France
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Shaw A, Jeromson S, Watterson KR, Pediani JD, Gallagher IJ, Whalley T, Dreczkowski G, Brooks N, Galloway SD, Hamilton DL. Multiple AMPK activators inhibit l-carnitine uptake in C2C12 skeletal muscle myotubes. Am J Physiol Cell Physiol 2017; 312:C689-C696. [PMID: 28298333 DOI: 10.1152/ajpcell.00026.2016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Revised: 02/21/2017] [Accepted: 03/14/2017] [Indexed: 12/29/2022]
Abstract
Mutations in the gene that encodes the principal l-carnitine transporter, OCTN2, can lead to a reduced intracellular l-carnitine pool and the disease Primary Carnitine Deficiency. l-Carnitine supplementation is used therapeutically to increase intracellular l-carnitine. As AMPK and insulin regulate fat metabolism and substrate uptake, we hypothesized that AMPK-activating compounds and insulin would increase l-carnitine uptake in C2C12 myotubes. The cells express all three OCTN transporters at the mRNA level, and immunohistochemistry confirmed expression at the protein level. Contrary to our hypothesis, despite significant activation of PKB and 2DG uptake, insulin did not increase l-carnitine uptake at 100 nM. However, l-carnitine uptake was modestly increased at a dose of 150 nM insulin. A range of AMPK activators that increase intracellular calcium content [caffeine (10 mM, 5 mM, 1 mM, 0.5 mM), A23187 (10 μM)], inhibit mitochondrial function [sodium azide (75 μM), rotenone (1 μM), berberine (100 μM), DNP (500 μM)], or directly activate AMPK [AICAR (250 μM)] were assessed for their ability to regulate l-carnitine uptake. All compounds tested significantly inhibited l-carnitine uptake. Inhibition by caffeine was not dantrolene (10 μM) sensitive despite dantrolene inhibiting caffeine-mediated calcium release. Saturation curve analysis suggested that caffeine did not competitively inhibit l-carnitine transport. To assess the potential role of AMPK in this process, we assessed the ability of the AMPK inhibitor Compound C (10 μM) to rescue the effect of caffeine. Compound C offered a partial rescue of l-carnitine uptake with 0.5 mM caffeine, suggesting that AMPK may play a role in the inhibitory effects of caffeine. However, caffeine likely inhibits l-carnitine uptake by alternative mechanisms independently of calcium release. PKA activation or direct interference with transporter function may play a role.
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Affiliation(s)
- Andy Shaw
- Physiology, Exercise and Nutrition Research Group, Faculty of Health Sciences and Sport, University of Stirling, Stirling, United Kingdom
| | - Stewart Jeromson
- Physiology, Exercise and Nutrition Research Group, Faculty of Health Sciences and Sport, University of Stirling, Stirling, United Kingdom
| | - Kenneth R Watterson
- Molecular Pharmacology Group, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom; and
| | - John D Pediani
- Molecular Pharmacology Group, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom; and
| | - Iain J Gallagher
- Physiology, Exercise and Nutrition Research Group, Faculty of Health Sciences and Sport, University of Stirling, Stirling, United Kingdom
| | - Tim Whalley
- Biological and Environmental Sciences, School of Natural Sciences, University of Stirling, Stirling, United Kingdom
| | - Gillian Dreczkowski
- Physiology, Exercise and Nutrition Research Group, Faculty of Health Sciences and Sport, University of Stirling, Stirling, United Kingdom
| | - Naomi Brooks
- Physiology, Exercise and Nutrition Research Group, Faculty of Health Sciences and Sport, University of Stirling, Stirling, United Kingdom
| | - Stuart D Galloway
- Physiology, Exercise and Nutrition Research Group, Faculty of Health Sciences and Sport, University of Stirling, Stirling, United Kingdom
| | - D Lee Hamilton
- Physiology, Exercise and Nutrition Research Group, Faculty of Health Sciences and Sport, University of Stirling, Stirling, United Kingdom;
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Szkudelski T, Szkudelska K. Effects of AMPK activation on lipolysis in primary rat adipocytes: studies at different glucose concentrations. Arch Physiol Biochem 2017; 123:43-49. [PMID: 27656952 DOI: 10.1080/13813455.2016.1227853] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Adipose tissue plays a key role in energy homeostasis. Adenosine monophosphate (AMP)-activated protein kinase (AMPK) is an important intracellular energy sensor. Effects of activation of AMPK by aminomidazole-4-carboxamide ribonucleotide (AICAR) on lipolysis in the rat adipocytes were determined in the presence of 3 or 12 mM glucose. Response to epinephrine or dibutyryl-cAMP was higher in the presence of 12 mM glucose. AICAR decreased lipolysis, also when glucose was replaced by alanine or succinate and without decrease in cAMP levels. AICAR attenuated epinephrine-induced decrease in adenosine triphosphate (ATP) levels, reduced glucose uptake and lactate release. These results indicate that short-term activation of AMPK by AICAR in the rat adipocytes inhibits lipolysis, due to changes in the final, followed by protein kinase A (PKA), steps of the lipolytic cascade and improves intracellular energy status. Similar effects of AICAR were observed in the presence of 3 and 12 mM glucose, which indicates that the AMPK system is operative at high glucose concentrations.
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Affiliation(s)
- Tomasz Szkudelski
- a Department of Animal Physiology and Biochemistry , Poznan University of Life Sciences , Poznan , Poland
| | - Katarzyna Szkudelska
- a Department of Animal Physiology and Biochemistry , Poznan University of Life Sciences , Poznan , Poland
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38
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The modern interleukin-1 superfamily: Divergent roles in obesity. Semin Immunol 2016; 28:441-449. [DOI: 10.1016/j.smim.2016.10.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Revised: 10/03/2016] [Accepted: 10/03/2016] [Indexed: 11/20/2022]
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Vavrova E, Lenoir V, Alves-Guerra MC, Denis RG, Castel J, Esnous C, Dyck JRB, Luquet S, Metzger D, Bouillaud F, Prip-Buus C. Muscle expression of a malonyl-CoA-insensitive carnitine palmitoyltransferase-1 protects mice against high-fat/high-sucrose diet-induced insulin resistance. Am J Physiol Endocrinol Metab 2016; 311:E649-60. [PMID: 27507552 DOI: 10.1152/ajpendo.00020.2016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Accepted: 08/09/2016] [Indexed: 12/17/2022]
Abstract
Impaired skeletal muscle mitochondrial fatty acid oxidation (mFAO) has been implicated in the etiology of insulin resistance. Carnitine palmitoyltransferase-1 (CPT1) is a key regulatory enzyme of mFAO whose activity is inhibited by malonyl-CoA, a lipogenic intermediate. Whereas increasing CPT1 activity in vitro has been shown to exert a protective effect against lipid-induced insulin resistance in skeletal muscle cells, only a few studies have addressed this issue in vivo. We thus examined whether a direct modulation of muscle CPT1/malonyl-CoA partnership is detrimental or beneficial for insulin sensitivity in the context of diet-induced obesity. By using a Cre-LoxP recombination approach, we generated mice with skeletal muscle-specific and inducible expression of a mutated CPT1 form (CPT1mt) that is active but insensitive to malonyl-CoA inhibition. When fed control chow, homozygous CPT1mt transgenic (dbTg) mice exhibited decreased CPT1 sensitivity to malonyl-CoA inhibition in isolated muscle mitochondria, which was sufficient to substantially increase ex vivo muscle mFAO capacity and whole body fatty acid utilization in vivo. Moreover, dbTg mice were less prone to high-fat/high-sucrose (HFHS) diet-induced insulin resistance and muscle lipotoxicity despite similar body weight gain, adiposity, and muscle malonyl-CoA content. Interestingly, these CPT1mt-protective effects in dbTg-HFHS mice were associated with preserved muscle insulin signaling, increased muscle glycogen content, and upregulation of key genes involved in muscle glucose metabolism. These beneficial effects of muscle CPT1mt expression suggest that a direct modulation of the malonyl-CoA/CPT1 partnership in skeletal muscle could represent a potential strategy to prevent obesity-induced insulin resistance.
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Affiliation(s)
- Eliska Vavrova
- Institut National de la Santé et de la Recherche Médicale, U1016, Institut Cochin, Paris, France; Centre National de la Recherche Scientifique, UMR8104, Paris, France; Université Paris Descartes, Sorbonne Paris Cité, Paris, France; Université Paris Diderot, Paris, France
| | - Véronique Lenoir
- Institut National de la Santé et de la Recherche Médicale, U1016, Institut Cochin, Paris, France; Centre National de la Recherche Scientifique, UMR8104, Paris, France; Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Marie-Clotilde Alves-Guerra
- Institut National de la Santé et de la Recherche Médicale, U1016, Institut Cochin, Paris, France; Centre National de la Recherche Scientifique, UMR8104, Paris, France; Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Raphaël G Denis
- Université Paris Diderot, Sorbonne Paris Cité, Unité de Biologie Fonctionnelle et Adaptative, Centre National de la Recherche Scientifique UMR8251, Paris, France
| | - Julien Castel
- Université Paris Diderot, Sorbonne Paris Cité, Unité de Biologie Fonctionnelle et Adaptative, Centre National de la Recherche Scientifique UMR8251, Paris, France
| | - Catherine Esnous
- Institut National de la Santé et de la Recherche Médicale, U1016, Institut Cochin, Paris, France; Centre National de la Recherche Scientifique, UMR8104, Paris, France; Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Jason R B Dyck
- Cardiovascular Research Centre, Department of Pediatrics, University of Alberta, Edmonton, Alberta, Canada
| | - Serge Luquet
- Université Paris Diderot, Sorbonne Paris Cité, Unité de Biologie Fonctionnelle et Adaptative, Centre National de la Recherche Scientifique UMR8251, Paris, France
| | - Daniel Metzger
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Institut National de la Santé et de la Recherche Médicale, U964, Centre National de la Recherche Scientifique, UMR7104, Université de Strasbourg, Illkirch, France
| | - Frédéric Bouillaud
- Institut National de la Santé et de la Recherche Médicale, U1016, Institut Cochin, Paris, France; Centre National de la Recherche Scientifique, UMR8104, Paris, France; Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Carina Prip-Buus
- Institut National de la Santé et de la Recherche Médicale, U1016, Institut Cochin, Paris, France; Centre National de la Recherche Scientifique, UMR8104, Paris, France; Université Paris Descartes, Sorbonne Paris Cité, Paris, France;
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Affourtit C. Mitochondrial involvement in skeletal muscle insulin resistance: A case of imbalanced bioenergetics. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2016; 1857:1678-93. [PMID: 27473535 DOI: 10.1016/j.bbabio.2016.07.008] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Revised: 06/19/2016] [Accepted: 07/23/2016] [Indexed: 12/16/2022]
Abstract
Skeletal muscle insulin resistance in obesity associates with mitochondrial dysfunction, but the causality of this association is controversial. This review evaluates mitochondrial models of nutrient-induced muscle insulin resistance. It transpires that all models predict that insulin resistance arises as a result of imbalanced cellular bioenergetics. The nature and precise origin of the proposed insulin-numbing molecules differ between models but all species only accumulate when metabolic fuel supply outweighs energy demand. This observation suggests that mitochondrial deficiency in muscle insulin resistance is not merely owing to intrinsic functional defects, but could instead be an adaptation to nutrient-induced changes in energy expenditure. Such adaptive effects are likely because muscle ATP supply is fully driven by energy demand. This market-economic control of myocellular bioenergetics offers a mechanism by which insulin-signalling deficiency can cause apparent mitochondrial dysfunction, as insulin resistance lowers skeletal muscle anabolism and thus dampens ATP demand and, consequently, oxidative ATP synthesis.
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Affiliation(s)
- Charles Affourtit
- School of Biomedical and Healthcare Sciences, Plymouth University Peninsula Schools of Medicine and Dentistry, Plymouth University, Drake Circus, PL4 8AA Plymouth, UK.
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41
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Most J, Timmers S, Warnke I, Jocken JW, van Boekschoten M, de Groot P, Bendik I, Schrauwen P, Goossens GH, Blaak EE. Combined epigallocatechin-3-gallate and resveratrol supplementation for 12 wk increases mitochondrial capacity and fat oxidation, but not insulin sensitivity, in obese humans: a randomized controlled trial. Am J Clin Nutr 2016; 104:215-27. [PMID: 27194304 DOI: 10.3945/ajcn.115.122937] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Accepted: 04/19/2016] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND The obese insulin-resistant state is characterized by impairments in lipid metabolism. We previously showed that 3-d supplementation of combined epigallocatechin-3-gallate and resveratrol (EGCG+RES) increased energy expenditure and improved the capacity to switch from fat toward carbohydrate oxidation with a high-fat mixed meal (HFMM) test in men. OBJECTIVE The present study aimed to investigate the longer-term effect of EGCG+RES supplementation on metabolic profile, mitochondrial capacity, fat oxidation, lipolysis, and tissue-specific insulin sensitivity. DESIGN In this randomized double-blind study, 38 overweight and obese subjects [18 men; aged 38 ± 2 y; body mass index (kg/m(2)): 29.7 ± 0.5] received either EGCG+RES (282 and 80 mg/d, respectively) or placebo for 12 wk. Before and after the intervention, oxidative capacity and gene expression were assessed in skeletal muscle. Fasting and postprandial (HFMM) lipid metabolism was assessed by using indirect calorimetry, blood sampling, and microdialysis. Tissue-specific insulin sensitivity was assessed by a hyperinsulinemic-euglycemic clamp with [6,6-(2)H2]-glucose infusion. RESULTS EGCG+RES supplementation did not affect the fasting plasma metabolic profile. Although whole-body fat mass was not affected, visceral adipose tissue mass tended to decrease after the intervention compared with placebo (P-time × treatment = 0.09). EGCG+RES supplementation significantly increased oxidative capacity in permeabilized muscle fibers (P-time × treatment < 0.05, P-EGCG+RES < 0.05). Moreover, EGCG+RES reduced fasting (P-time × treatment = 0.03) and postprandial respiratory quotient (P-time × treatment = 0.01) compared with placebo. Fasting and postprandial fat oxidation was not significantly affected by EGCG+RES (P-EGCG+RES = 0.46 and 0.38, respectively) but declined after placebo (P-placebo = 0.05 and 0.03, respectively). Energy expenditure was not altered (P-time × treatment = 0.96). Furthermore, EGCG+RES supplementation attenuated the increase in plasma triacylglycerol concentrations during the HFMM test that was observed after placebo (P-time × treatment = 0.04, P-placebo = 0.01). Finally, EGCG+RES had no effect on insulin-stimulated glucose disposal, suppression of endogenous glucose production, or lipolysis. CONCLUSION Twelve weeks of EGCG+RES supplementation increased mitochondrial capacity and stimulated fat oxidation compared with placebo, but this did not translate into increased tissue-specific insulin sensitivity in overweight and obese subjects. This trial was registered at clinicaltrials.gov as NCT02381145.
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Affiliation(s)
- Jasper Most
- Department of Human Biology, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Center, Maastricht, Netherlands
| | - Silvie Timmers
- Department of Human Biology, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Center, Maastricht, Netherlands
| | - Ines Warnke
- Research and Development, Human Nutrition and Health, DSM Nutritional Products Ltd., Basel, Switzerland; and
| | - Johan We Jocken
- Department of Human Biology, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Center, Maastricht, Netherlands
| | - Mark van Boekschoten
- Nutrition, Metabolism, and Genomics Group, Division of Human Nutrition, Wageningen University, Wageningen, Netherlands
| | - Philip de Groot
- Nutrition, Metabolism, and Genomics Group, Division of Human Nutrition, Wageningen University, Wageningen, Netherlands
| | - Igor Bendik
- Research and Development, Human Nutrition and Health, DSM Nutritional Products Ltd., Basel, Switzerland; and
| | - Patrick Schrauwen
- Department of Human Biology, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Center, Maastricht, Netherlands
| | - Gijs H Goossens
- Department of Human Biology, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Center, Maastricht, Netherlands
| | - Ellen E Blaak
- Department of Human Biology, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Center, Maastricht, Netherlands;
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42
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Regulatory principles in metabolism–then and now. Biochem J 2016; 473:1845-57. [DOI: 10.1042/bcj20160103] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Accepted: 03/21/2016] [Indexed: 12/22/2022]
Abstract
The importance of metabolic pathways for life and the nature of participating reactions have challenged physiologists and biochemists for over a hundred years. Eric Arthur Newsholme contributed many original hypotheses and concepts to the field of metabolic regulation, demonstrating that metabolic pathways have a fundamental thermodynamic structure and that near identical regulatory mechanisms exist in multiple species across the animal kingdom. His work at Oxford University from the 1970s to 1990s was groundbreaking and led to better understanding of development and demise across the lifespan as well as the basis of metabolic disruption responsible for the development of obesity, diabetes and many other conditions. In the present review we describe some of the original work of Eric Newsholme, its relevance to metabolic homoeostasis and disease and application to present state-of-the-art studies, which generate substantial amounts of data that are extremely difficult to interpret without a fundamental understanding of regulatory principles. Eric's work is a classical example of how one can unravel very complex problems by considering regulation from a cell, tissue and whole body perspective, thus bringing together metabolic biochemistry, physiology and pathophysiology, opening new avenues that now drive discovery decades thereafter.
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Cordonier EL, Jarecke SK, Hollinger FE, Zempleni J. Inhibition of acetyl-CoA carboxylases by soraphen A prevents lipid accumulation and adipocyte differentiation in 3T3-L1 cells. Eur J Pharmacol 2016; 780:202-8. [PMID: 27041646 DOI: 10.1016/j.ejphar.2016.03.052] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Revised: 03/22/2016] [Accepted: 03/29/2016] [Indexed: 10/22/2022]
Abstract
Acetyl-CoA carboxylases (ACC) 1 and 2 catalyze the carboxylation of acetyl-CoA to malonyl-CoA and depend on biotin as a coenzyme. ACC1 localizes in the cytoplasm and produces malonyl-CoA for fatty acid (FA) synthesis. ACC2 localizes in the outer mitochondrial membrane and produces malonyl-CoA that inhibits FA import into mitochondria for subsequent oxidation. We hypothesized that ACCs are checkpoints in adipocyte differentiation and tested this hypothesis using the ACC1 and ACC2 inhibitor soraphen A (SA) in murine 3T3-L1 preadipocytes. When 3T3-L1 cells were treated with 100nM SA for 8 days after induction of differentiation, the expression of PPARγ mRNA and FABP4 mRNA decreased by 40% and 50%, respectively, compared with solvent controls; the decrease in gene expression was accompanied by a decrease in FABP4 protein expression and associated with a decrease in lipid droplet accumulation. The rate of FA oxidation was 300% greater in SA-treated cells compared with vehicle controls. Treatment with exogenous palmitate restored PPARγ and FABP4 mRNA expression and FABP4 protein expression in SA-treated cells. In contrast, SA did not alter lipid accumulation if treatment was initiated on day eight after induction of differentiation. We conclude that loss of ACC1-dependent FA synthesis and loss of ACC2-dependent inhibition of FA oxidation prevent lipid accumulation in adipocytes and inhibit early stages of adipocyte differentiation.
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Affiliation(s)
- Elizabeth L Cordonier
- Department of Nutrition and Health Sciences, University of Nebraska-Lincoln, 316 Leverton Hall, Lincoln, NE 68583-0806, USA
| | - Sarah K Jarecke
- Department of Nutrition and Health Sciences, University of Nebraska-Lincoln, 316 Leverton Hall, Lincoln, NE 68583-0806, USA
| | - Frances E Hollinger
- Department of Nutrition and Health Sciences, University of Nebraska-Lincoln, 316 Leverton Hall, Lincoln, NE 68583-0806, USA
| | - Janos Zempleni
- Department of Nutrition and Health Sciences, University of Nebraska-Lincoln, 316 Leverton Hall, Lincoln, NE 68583-0806, USA.
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Acetyl-CoA carboxylase inhibition by ND-630 reduces hepatic steatosis, improves insulin sensitivity, and modulates dyslipidemia in rats. Proc Natl Acad Sci U S A 2016; 113:E1796-805. [PMID: 26976583 DOI: 10.1073/pnas.1520686113] [Citation(s) in RCA: 208] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Simultaneous inhibition of the acetyl-CoA carboxylase (ACC) isozymes ACC1 and ACC2 results in concomitant inhibition of fatty acid synthesis and stimulation of fatty acid oxidation and may favorably affect the morbidity and mortality associated with obesity, diabetes, and fatty liver disease. Using structure-based drug design, we have identified a series of potent allosteric protein-protein interaction inhibitors, exemplified by ND-630, that interact within the ACC phosphopeptide acceptor and dimerization site to prevent dimerization and inhibit the enzymatic activity of both ACC isozymes, reduce fatty acid synthesis and stimulate fatty acid oxidation in cultured cells and in animals, and exhibit favorable drug-like properties. When administered chronically to rats with diet-induced obesity, ND-630 reduces hepatic steatosis, improves insulin sensitivity, reduces weight gain without affecting food intake, and favorably affects dyslipidemia. When administered chronically to Zucker diabetic fatty rats, ND-630 reduces hepatic steatosis, improves glucose-stimulated insulin secretion, and reduces hemoglobin A1c (0.9% reduction). Together, these data suggest that ACC inhibition by representatives of this series may be useful in treating a variety of metabolic disorders, including metabolic syndrome, type 2 diabetes mellitus, and fatty liver disease.
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45
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Brandon AE, Stuart E, Leslie SJ, Hoehn KL, James DE, Kraegen EW, Turner N, Cooney GJ. Minimal impact of age and housing temperature on the metabolic phenotype of Acc2-/- mice. J Endocrinol 2016; 228:127-34. [PMID: 26668208 PMCID: PMC4906541 DOI: 10.1530/joe-15-0444] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/14/2015] [Indexed: 12/13/2022]
Abstract
An important regulator of fatty acid oxidation (FAO) is the allosteric inhibition of CPT-1 by malonyl-CoA produced by the enzyme acetyl-CoA carboxylase 2 (ACC2). Initial studies suggested that deletion of Acc2 (Acacb) increased fat oxidation and reduced adipose tissue mass but in an independently generated strain of Acc2 knockout mice we observed increased whole-body and skeletal muscle FAO and a compensatory increase in muscle glycogen stores without changes in glucose tolerance, energy expenditure or fat mass in young mice (12-16 weeks). The aim of the present study was to determine whether there was any effect of age or housing at thermoneutrality (29 °C; which reduces total energy expenditure) on the phenotype of Acc2 knockout mice. At 42-54 weeks of age, male WT and Acc2(-/-) mice had similar body weight, fat mass, muscle triglyceride content and glucose tolerance. Consistent with younger Acc2(-/-) mice, aged Acc2(-/-) mice showed increased whole-body FAO (24 h average respiratory exchange ratio=0.95±0.02 and 0.92±0.02 for WT and Acc2(-/-) mice respectively, P<0.05) and skeletal muscle glycogen content (+60%, P<0.05) without any detectable change in whole-body energy expenditure. Hyperinsulinaemic-euglycaemic clamp studies revealed no difference in insulin action between groups with similar glucose infusion rates and tissue glucose uptake. Housing Acc2(-/-) mice at 29 °C did not alter body composition, glucose tolerance or the effects of fat feeding compared with WT mice. These results confirm that manipulation of Acc2 may alter FAO in mice, but this has little impact on body composition or insulin action.
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Affiliation(s)
- Amanda E Brandon
- Diabetes and Metabolism DivisionGarvan Institute of Medical Research, 384 Victoria Street, Darlinghurst, New South Wales 2010, AustraliaSt Vincent's Clinical SchoolUniversity of New South Wales Australia, Sydney, New South Wales, AustraliaSchool of Medical SciencesUniversity of New South Wales Australia, Sydney, New South Wales, AustraliaSchool of Biotechnology and Biomolecular SciencesUniversity of New South Wales Australia, Sydney, New South Wales, AustraliaSchool of Molecular Bioscience and Sydney Medical SchoolCharles Perkins Centre, The University of Sydney, Sydney, New South Wales, Australia Diabetes and Metabolism DivisionGarvan Institute of Medical Research, 384 Victoria Street, Darlinghurst, New South Wales 2010, AustraliaSt Vincent's Clinical SchoolUniversity of New South Wales Australia, Sydney, New South Wales, AustraliaSchool of Medical SciencesUniversity of New South Wales Australia, Sydney, New South Wales, AustraliaSchool of Biotechnology and Biomolecular SciencesUniversity of New South Wales Australia, Sydney, New South Wales, AustraliaSchool of Molecular Bioscience and Sydney Medical SchoolCharles Perkins Centre, The University of Sydney, Sydney, New South Wales, Australia
| | - Ella Stuart
- Diabetes and Metabolism DivisionGarvan Institute of Medical Research, 384 Victoria Street, Darlinghurst, New South Wales 2010, AustraliaSt Vincent's Clinical SchoolUniversity of New South Wales Australia, Sydney, New South Wales, AustraliaSchool of Medical SciencesUniversity of New South Wales Australia, Sydney, New South Wales, AustraliaSchool of Biotechnology and Biomolecular SciencesUniversity of New South Wales Australia, Sydney, New South Wales, AustraliaSchool of Molecular Bioscience and Sydney Medical SchoolCharles Perkins Centre, The University of Sydney, Sydney, New South Wales, Australia
| | - Simon J Leslie
- Diabetes and Metabolism DivisionGarvan Institute of Medical Research, 384 Victoria Street, Darlinghurst, New South Wales 2010, AustraliaSt Vincent's Clinical SchoolUniversity of New South Wales Australia, Sydney, New South Wales, AustraliaSchool of Medical SciencesUniversity of New South Wales Australia, Sydney, New South Wales, AustraliaSchool of Biotechnology and Biomolecular SciencesUniversity of New South Wales Australia, Sydney, New South Wales, AustraliaSchool of Molecular Bioscience and Sydney Medical SchoolCharles Perkins Centre, The University of Sydney, Sydney, New South Wales, Australia
| | - Kyle L Hoehn
- Diabetes and Metabolism DivisionGarvan Institute of Medical Research, 384 Victoria Street, Darlinghurst, New South Wales 2010, AustraliaSt Vincent's Clinical SchoolUniversity of New South Wales Australia, Sydney, New South Wales, AustraliaSchool of Medical SciencesUniversity of New South Wales Australia, Sydney, New South Wales, AustraliaSchool of Biotechnology and Biomolecular SciencesUniversity of New South Wales Australia, Sydney, New South Wales, AustraliaSchool of Molecular Bioscience and Sydney Medical SchoolCharles Perkins Centre, The University of Sydney, Sydney, New South Wales, Australia
| | - David E James
- Diabetes and Metabolism DivisionGarvan Institute of Medical Research, 384 Victoria Street, Darlinghurst, New South Wales 2010, AustraliaSt Vincent's Clinical SchoolUniversity of New South Wales Australia, Sydney, New South Wales, AustraliaSchool of Medical SciencesUniversity of New South Wales Australia, Sydney, New South Wales, AustraliaSchool of Biotechnology and Biomolecular SciencesUniversity of New South Wales Australia, Sydney, New South Wales, AustraliaSchool of Molecular Bioscience and Sydney Medical SchoolCharles Perkins Centre, The University of Sydney, Sydney, New South Wales, Australia
| | - Edward W Kraegen
- Diabetes and Metabolism DivisionGarvan Institute of Medical Research, 384 Victoria Street, Darlinghurst, New South Wales 2010, AustraliaSt Vincent's Clinical SchoolUniversity of New South Wales Australia, Sydney, New South Wales, AustraliaSchool of Medical SciencesUniversity of New South Wales Australia, Sydney, New South Wales, AustraliaSchool of Biotechnology and Biomolecular SciencesUniversity of New South Wales Australia, Sydney, New South Wales, AustraliaSchool of Molecular Bioscience and Sydney Medical SchoolCharles Perkins Centre, The University of Sydney, Sydney, New South Wales, Australia Diabetes and Metabolism DivisionGarvan Institute of Medical Research, 384 Victoria Street, Darlinghurst, New South Wales 2010, AustraliaSt Vincent's Clinical SchoolUniversity of New South Wales Australia, Sydney, New South Wales, AustraliaSchool of Medical SciencesUniversity of New South Wales Australia, Sydney, New South Wales, AustraliaSchool of Biotechnology and Biomolecular SciencesUniversity of New South Wales Australia, Sydney, New South Wales, AustraliaSchool of Molecular Bioscience and Sydney Medical SchoolCharles Perkins Centre, The University of Sydney, Sydney, New South Wales, Australia
| | - Nigel Turner
- Diabetes and Metabolism DivisionGarvan Institute of Medical Research, 384 Victoria Street, Darlinghurst, New South Wales 2010, AustraliaSt Vincent's Clinical SchoolUniversity of New South Wales Australia, Sydney, New South Wales, AustraliaSchool of Medical SciencesUniversity of New South Wales Australia, Sydney, New South Wales, AustraliaSchool of Biotechnology and Biomolecular SciencesUniversity of New South Wales Australia, Sydney, New South Wales, AustraliaSchool of Molecular Bioscience and Sydney Medical SchoolCharles Perkins Centre, The University of Sydney, Sydney, New South Wales, Australia
| | - Gregory J Cooney
- Diabetes and Metabolism DivisionGarvan Institute of Medical Research, 384 Victoria Street, Darlinghurst, New South Wales 2010, AustraliaSt Vincent's Clinical SchoolUniversity of New South Wales Australia, Sydney, New South Wales, AustraliaSchool of Medical SciencesUniversity of New South Wales Australia, Sydney, New South Wales, AustraliaSchool of Biotechnology and Biomolecular SciencesUniversity of New South Wales Australia, Sydney, New South Wales, AustraliaSchool of Molecular Bioscience and Sydney Medical SchoolCharles Perkins Centre, The University of Sydney, Sydney, New South Wales, Australia Diabetes and Metabolism DivisionGarvan Institute of Medical Research, 384 Victoria Street, Darlinghurst, New South Wales 2010, AustraliaSt Vincent's Clinical SchoolUniversity of New South Wales Australia, Sydney, New South Wales, AustraliaSchool of Medical SciencesUniversity of New South Wales Australia, Sydney, New South Wales, AustraliaSchool of Biotechnology and Biomolecular SciencesUniversity of New South Wales Australia, Sydney, New South Wales, AustraliaSchool of Molecular Bioscience and Sydney Medical SchoolCharles Perkins Centre, The University of Sydney, Sydney, New South Wales, Australia
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Healy ME, Lahiri S, Hargett SR, Chow JDY, Byrne FL, Breen DS, Kenwood BM, Taddeo EP, Lackner C, Caldwell SH, Hoehn KL. Dietary sugar intake increases liver tumor incidence in female mice. Sci Rep 2016; 6:22292. [PMID: 26924712 PMCID: PMC4770276 DOI: 10.1038/srep22292] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Accepted: 02/11/2016] [Indexed: 12/21/2022] Open
Abstract
Overnutrition can promote liver cancer in mice and humans that have liver damage caused by alcohol, viruses, or carcinogens. However, the mechanism linking diet to increased liver tumorigenesis remains unclear in the context of whether tumorigenesis is secondary to obesity, or whether nutrients like sugar or fat drive tumorigenesis independent of obesity. In male mice, liver tumor burden was recently found to correlate with sugar intake, independent of dietary fat intake and obesity. However, females are less susceptible to developing liver cancer than males, and it remains unclear how nutrition affects tumorigenesis in females. Herein, female mice were exposed to the liver carcinogen diethylnitrosamine (DEN) and fed diets with well-defined sugar and fat content. Mice fed diets with high sugar content had the greatest liver tumor incidence while dietary fat intake was not associated with tumorigenesis. Diet-induced postprandial hyperglycemia and fasting hyperinsulinemia significantly correlated with tumor incidence, while tumor incidence was not associated with obesity and obesity-related disorders including liver steatosis, glucose intolerance, or elevated serum levels of estrogen, ALT, and lipids. These results simplify the pathophysiology of diet-induced liver tumorigenesis by focusing attention on the role of sugar metabolism and reducing emphasis on the complex milieu associated with obesity.
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Affiliation(s)
- Marin E Healy
- Department of Pharmacology, University of Virginia, Charlottesville, VA, USA
| | - Sujoy Lahiri
- Department of Pharmacology, University of Virginia, Charlottesville, VA, USA
| | - Stefan R Hargett
- Department of Pharmacology, University of Virginia, Charlottesville, VA, USA
| | - Jenny D Y Chow
- Department of Pharmacology, University of Virginia, Charlottesville, VA, USA
| | - Frances L Byrne
- Department of Pharmacology, University of Virginia, Charlottesville, VA, USA.,School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, Australia
| | - David S Breen
- Department of Pharmacology, University of Virginia, Charlottesville, VA, USA
| | - Brandon M Kenwood
- Department of Pharmacology, University of Virginia, Charlottesville, VA, USA
| | - Evan P Taddeo
- Department of Pharmacology, University of Virginia, Charlottesville, VA, USA
| | - Carolin Lackner
- Institute of Pathology, Medical University of Graz, Graz, Austria
| | - Stephen H Caldwell
- Department of Medicine, University of Virginia, Charlottesville, VA, USA.,Emily Couric Clinical Cancer Center, University of Virginia, Charlottesville, VA, USA
| | - Kyle L Hoehn
- Department of Pharmacology, University of Virginia, Charlottesville, VA, USA.,Department of Medicine, University of Virginia, Charlottesville, VA, USA.,Emily Couric Clinical Cancer Center, University of Virginia, Charlottesville, VA, USA.,School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, Australia
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47
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Magdalon J, Chimin P, Belchior T, Neves RX, Vieira-Lara MA, Andrade ML, Farias TS, Bolsoni-Lopes A, Paschoal VA, Yamashita AS, Kowaltowski AJ, Festuccia WT. Constitutive adipocyte mTORC1 activation enhances mitochondrial activity and reduces visceral adiposity in mice. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1861:430-8. [PMID: 26923434 DOI: 10.1016/j.bbalip.2016.02.023] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Revised: 01/26/2016] [Accepted: 02/24/2016] [Indexed: 10/22/2022]
Abstract
Mechanistic target of rapamycin complex 1 (mTORC1) loss of function reduces adiposity whereas partial mTORC1 inhibition enhances fat deposition. Herein we evaluated how constitutive mTORC1 activation in adipocytes modulates adiposity in vivo. Mice with constitutive mTORC1 activation in adipocytes induced by tuberous sclerosis complex (Tsc)1 deletion and littermate controls were evaluated for body mass, energy expenditure, glucose and fatty acid metabolism, mitochondrial function, mRNA and protein contents. Adipocyte-specific Tsc1 deletion reduced visceral, but not subcutaneous, fat mass, as well as adipocyte number and diameter, phenotypes that were associated with increased lipolysis, UCP-1 content (browning) and mRNA levels of pro-browning transcriptional factors C/EBPβ and ERRα. Adipocyte Tsc1 deletion enhanced mitochondrial oxidative activity, fatty acid oxidation and the expression of PGC-1α and PPARα in both visceral and subcutaneous fat. In brown adipocytes, however, Tsc1 deletion did not affect UCP-1 content and basal respiration. Adipocyte Tsc1 deletion also reduced visceral adiposity and enhanced glucose tolerance, liver and muscle insulin signaling and adiponectin secretion in mice fed with purified low- or high-fat diet. In conclusion, adipocyte-specific Tsc1 deletion enhances mitochondrial activity, induces browning and reduces visceral adiposity in mice.
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Affiliation(s)
- Juliana Magdalon
- Departmento de Fisiologia e Biofísica, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo 05508000, Brazil
| | - Patricia Chimin
- Departmento de Fisiologia e Biofísica, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo 05508000, Brazil
| | - Thiago Belchior
- Departmento de Fisiologia e Biofísica, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo 05508000, Brazil
| | - Rodrigo X Neves
- Departmento de Biologia Celular e do Desenvolvimento, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo 05508000, Brazil
| | - Marcel A Vieira-Lara
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo 05500900, Brazil
| | - Maynara L Andrade
- Departmento de Fisiologia e Biofísica, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo 05508000, Brazil
| | - Talita S Farias
- Departmento de Fisiologia e Biofísica, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo 05508000, Brazil
| | - Andressa Bolsoni-Lopes
- Departmento de Fisiologia e Biofísica, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo 05508000, Brazil
| | - Vivian A Paschoal
- Departmento de Fisiologia e Biofísica, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo 05508000, Brazil
| | - Alex S Yamashita
- Departmento de Fisiologia e Biofísica, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo 05508000, Brazil
| | - Alicia J Kowaltowski
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo 05500900, Brazil
| | - William T Festuccia
- Departmento de Fisiologia e Biofísica, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo 05508000, Brazil.
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Petróczi A, Ocampo JAV, Shah I, Jenkinson C, New R, James RA, Taylor G, Naughton DP. Russian roulette with unlicensed fat-burner drug 2,4-dinitrophenol (DNP): evidence from a multidisciplinary study of the internet, bodybuilding supplements and DNP users. SUBSTANCE ABUSE TREATMENT PREVENTION AND POLICY 2015; 10:39. [PMID: 26466580 PMCID: PMC4607104 DOI: 10.1186/s13011-015-0034-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Accepted: 09/25/2015] [Indexed: 11/12/2022]
Abstract
Background 2,4-Dinitrophenol (DNP) poses serious health-risks to humans. The aims of this three-stage multidisciplinary project were, for the first time, to assess the risks to the general public from fraudulent sale of or adulteration/contamination with DNP; and to investigate motives, reasons and risk-management among DNP-user bodybuilders and avid exercisers. Methods Using multiple search-engines and guidance for Internet research, online retailers and bodybuilding forums/blogs were systematically explored for availability of DNP, advice offered on DNP use and user profiles. Ninety-eight pre-workout and weight-loss supplements were purchased and analysed for DNP using liquid-chromatography-mass-spectrometry. Psychosocial variables were captured in an international sample of 35 DNP users (26.06 ± 6.10 years, 94.3 % male) with an anonymous, semi-qualitative self-reported survey. Results Although an industrial chemical, evidence from the Internet showed that DNP is sold ‘as is’, in capsules or tablets to suit human consumption, and is used ‘uncut’. Analytical results confirmed that DNP is not on the supplement market disguised under fictitious supplement names, but infrequently was present as contaminant in some supplements (14/98) at low concentration (<100mcg/kg). Users make conscious and ‘informed’ decisions about DNP; are well-prepared for the side-effects and show nonchalant attitude toward self-experimentation with DNP. Steps are often taken to ensure that DNP is genuine. Personal experience with performance- and appearance enhancing substances appears to be a gateway to DNP. Advice on DNP and experiences are shared online. The significant discrepancy between the normative perception and the actual visibility suggests that DNP use is-contrary to the Internet accounts-a highly concealed and lonesome activity in real life. Positive experiences with the expected weight-loss prevail over the negative experiences from side effects (all but two users considered using DNP again) and help with using DNP safely is considered preferable over scare-tactics. Conclusion Legislation banning DNP sale for human consumption protects the general public but DNP is sold ‘as is’ and used ‘uncut’ by determined users who are not dissuaded from experimenting with DNP based on health threats. Further research with stakeholders’ active participation is imperative for targeted, proactive public health policies and harm-reduction measures for DNP, and other illicit supplements. Electronic supplementary material The online version of this article (doi:10.1186/s13011-015-0034-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Andrea Petróczi
- Faculty of Science, Engineering and Computing, Kingston University London, Penrhyn Road, Kingston upon Thames, Surrey, KT1 2EE, United Kingdom.
| | - Jorge A Vela Ocampo
- Faculty of Science, Engineering and Computing, Kingston University London, Penrhyn Road, Kingston upon Thames, Surrey, KT1 2EE, United Kingdom.
| | - Iltaf Shah
- Faculty of Science, Engineering and Computing, Kingston University London, Penrhyn Road, Kingston upon Thames, Surrey, KT1 2EE, United Kingdom.
| | | | - Rachael New
- Hampshire County Council-Scientific Services, Hampshire, UK.
| | - Ricky A James
- Faculty of Science, Engineering and Computing, Kingston University London, Penrhyn Road, Kingston upon Thames, Surrey, KT1 2EE, United Kingdom.
| | - Glenn Taylor
- Hampshire County Council-Scientific Services, Hampshire, UK.
| | - Declan P Naughton
- Faculty of Science, Engineering and Computing, Kingston University London, Penrhyn Road, Kingston upon Thames, Surrey, KT1 2EE, United Kingdom.
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49
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Lee JE, Walsh MC, Hoehn KL, James DE, Wherry EJ, Choi Y. Acetyl CoA Carboxylase 2 Is Dispensable for CD8+ T Cell Responses. PLoS One 2015; 10:e0137776. [PMID: 26367121 PMCID: PMC4569334 DOI: 10.1371/journal.pone.0137776] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Accepted: 08/21/2015] [Indexed: 01/17/2023] Open
Abstract
Differentiation of T cells is closely associated with dynamic changes in nutrient and energy metabolism. However, the extent to which specific metabolic pathways and molecular components are determinative of CD8+ T cell fate remains unclear. It has been previously established in various tissues that acetyl CoA carboxylase 2 (ACC2) regulates fatty acid oxidation (FAO) by inhibiting carnitine palmitoyltransferase 1 (CPT1), a rate-limiting enzyme of FAO in mitochondria. Here, we explore the cell-intrinsic role of ACC2 in T cell immunity in response to infections. We report here that ACC2 deficiency results in a marginal increase of cellular FAO in CD8+ T cells, but does not appear to influence antigen-specific effector and memory CD8+ T cell responses during infection with listeria or lymphocytic choriomeningitis virus. These results suggest that ACC2 is dispensable for CD8+ T cell responses.
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Affiliation(s)
- Jang Eun Lee
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, 19104, United States of America
- Institute for Immunology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, 19104, United States of America
| | - Matthew C. Walsh
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, 19104, United States of America
- Institute for Immunology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, 19104, United States of America
| | - Kyle L. Hoehn
- Department of Pharmacology, University of Virginia Health System, Charlottesville, Virginia, 22908, United States of America
| | - David E. James
- Charles Perkins Centre Research and Education Hub, University of Sydney, Sydney, New South Wales, Australia
| | - E. John Wherry
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, 19104, United States of America
- Institute for Immunology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, 19104, United States of America
| | - Yongwon Choi
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, 19104, United States of America
- Institute for Immunology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, 19104, United States of America
- * E-mail:
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50
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Hargett SR, Walker NN, Hussain SS, Hoehn KL, Keller SR. Deletion of the Rab GAP Tbc1d1 modifies glucose, lipid, and energy homeostasis in mice. Am J Physiol Endocrinol Metab 2015; 309:E233-45. [PMID: 26015432 PMCID: PMC4525116 DOI: 10.1152/ajpendo.00007.2015] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Accepted: 05/24/2015] [Indexed: 11/22/2022]
Abstract
Tbc1d1 is a Rab GTPase-activating protein (GAP) implicated in regulating intracellular retention and cell surface localization of the glucose transporter GLUT4 and thus glucose uptake in a phosphorylation-dependent manner. Tbc1d1 is most abundant in skeletal muscle but is expressed at varying levels among different skeletal muscles. Previous studies with male Tbc1d1-deficient (Tbc1d1(-/-)) mice on standard and high-fat diets established a role for Tbc1d1 in glucose, lipid, and energy homeostasis. Here we describe similar, but also additional abnormalities in male and female Tbc1d1(-/-) mice. We corroborate that Tbc1d1 loss leads to skeletal muscle-specific and skeletal muscle type-dependent abnormalities in GLUT4 expression and glucose uptake in female and male mice. Using subcellular fractionation, we show that Tbc1d1 controls basal intracellular GLUT4 retention in large skeletal muscles. However, cell surface labeling of extensor digitorum longus muscle indicates that Tbc1d1 does not regulate basal GLUT4 cell surface exposure as previously suggested. Consistent with earlier observations, female and male Tbc1d1(-/-) mice demonstrate increased energy expenditure and skeletal muscle fatty acid oxidation. Interestingly, we observe sex-dependent differences in in vivo phenotypes. Female, but not male, Tbc1d1(-/-) mice have decreased body weight and impaired glucose and insulin tolerance, but only male Tbc1d1(-/-) mice show increased lipid clearance after oil gavage. We surmise that similar changes at the tissue level cause differences in whole-body metabolism between male and female Tbc1d1(-/-) mice and between male Tbc1d1(-/-) mice in different studies due to variations in body composition and nutrient handling.
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Affiliation(s)
- Stefan R Hargett
- Department of Medicine, Division of Endocrinology, University of Virginia, Charlottesville Virginia
| | - Natalie N Walker
- Department of Medicine, Division of Endocrinology, University of Virginia, Charlottesville Virginia
| | - Syed S Hussain
- Department of Medicine, Division of Endocrinology, University of Virginia, Charlottesville Virginia
| | - Kyle L Hoehn
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia
| | - Susanna R Keller
- Department of Medicine, Division of Endocrinology, University of Virginia, Charlottesville Virginia;
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