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Bradley CE, Fletcher E, Wilkinson T, Ring A, Ferrer L, Miserlis D, Pacher P, Koutakis P. Mitochondrial fatty acid beta-oxidation: a possible therapeutic target for skeletal muscle lipotoxicity in peripheral artery disease myopathy. EXCLI JOURNAL 2024; 23:523-533. [PMID: 38741727 PMCID: PMC11089102 DOI: 10.17179/excli2024-7004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Accepted: 04/10/2024] [Indexed: 05/16/2024]
Abstract
Peripheral artery disease (PAD) is an atherosclerotic disease impacting over 200 million individuals and the prevalence increases with age. PAD occurs when plaque builds up within the peripheral arteries, leading to reduced blood flow and oxygen supply to the outer extremities. Individuals who experience PAD suffer from ischemia, which is typically accompanied by significant damage to skeletal muscles. Additionally, this tissue damage affects mitochondria, causing them to become dysregulated and dysfunctional, resulting in decreased metabolic rates. As there is no known cure for PAD, researchers are exploring potential therapeutic targets by examining coexisting cardiovascular conditions and metabolic risk factors, such as the aging process. Among these comorbidities, type-two diabetes mellitus and obesity are particularly common in PAD cases. These conditions, along with aging itself, are associated with an elevated accumulation of ectopic lipids within skeletal muscles, similar to what is observed in PAD. Researchers have attempted to reduce excess lipid accumulation by increasing the rate of fatty acid beta oxidation. Manipulating acetyl coenzyme A carboxylase 2, a key regulatory protein of fatty acid beta oxidation, has been the primary focus of such research. When acetyl coenzyme A carboxylase 2 is inhibited, it interrupts the conversion of acetyl-CoA into malonyl-CoA, resulting in an increase in the rate of fatty acid beta oxidation. By utilizing samples from PAD patients and applying the pharmacological strategies developed for acetyl coenzyme A carboxylase 2 in diabetes and obesity to PAD, a potential new therapeutic avenue may emerge, offering hope for improved quality of life for individuals suffering from PAD.
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Affiliation(s)
- Cassandra E. Bradley
- Department of Biology, Baylor University, One Bear Place #97388, Waco, TX 76798, USA
| | - Emma Fletcher
- Department of Biology, Baylor University, One Bear Place #97388, Waco, TX 76798, USA
| | - Trevor Wilkinson
- Department of Biology, Baylor University, One Bear Place #97388, Waco, TX 76798, USA
| | - Andrew Ring
- Department of Biology, Baylor University, One Bear Place #97388, Waco, TX 76798, USA
| | - Lucas Ferrer
- Department of Surgery, University of Texas at Austin Dell Medical School, 1601 Trinity St, Room 6708A, Austin, TX 78712, USA
| | - Dimitrios Miserlis
- Department of Surgery, University of Texas at Austin Dell Medical School, 1601 Trinity St, Room 6708A, Austin, TX 78712, USA
| | - Pal Pacher
- National Institutes of Health, Bethesda, MD, USA
| | - Panagiotis Koutakis
- Department of Biology, Baylor University, One Bear Place #97388, Waco, TX 76798, USA
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2
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Cao M, Li X, Dong L, Wen H, Jiang M, Lu X, Huang F, Tian J. Molecular cloning and gene expression of acc2 from grass carp (Ctenopharyngodon idella) and the regulation of glucose metabolism by ACCs inhibitor. Mol Biol Rep 2024; 51:402. [PMID: 38456942 DOI: 10.1007/s11033-024-09286-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Accepted: 01/24/2024] [Indexed: 03/09/2024]
Abstract
BACKGROUND Acetyl-CoA carboxylase (ACC) catalyzes the carboxylation of acetyl-CoA to malonyl-CoA. Malonyl-CoA, which plays a key role in regulating glucose and lipid metabolism, is not only a substrate for fatty acid synthesis but also an inhibitor of the oxidation pathway. ACC exists as two isoenzymes that are encoded by two different genes. ACC1 in grass carp (Ctenopharyngodon idellus) has been cloned and sequenced. However, studies on the cloning, tissue distribution, and function of ACC2 in grass carp were still rare. METHODS AND RESULTS The full-length cDNA of acc2 was 8537 bp with a 7146 bp open reading frame encoding 2381 amino acids. ACC2 had a calculated molecular weight of 268.209 kDa and an isoelectric point of 5.85. ACC2 of the grass carp shared the closest relationship with that of the common carp (Sinocyclocheilus grahami). The expressions of acc1 and acc2 mRNA were detected in all examined tissues. The expression level of acc1 was high in the brain and fat but absent in the midgut and hindgut. The expression level of acc2 in the kidney was significantly higher than in other tissues, followed by the heart, brain, muscle, and spleen. ACCs inhibitor significantly reduced the levels of glucose, malonyl-CoA, and triglyceride in hepatocytes. CONCLUSIONS This study showed that the function of ACC2 was evolutionarily conserved from fish to mammals. ACCs inhibitor inhibited the biological activity of ACCs, and reduced fat accumulation in grass carp.
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Affiliation(s)
- Manxia Cao
- Key Laboratory for Animal Nutrition and Feed Science of Hubei Province, Wuhan Polytechnic University, Wuhan, 430023, China
- Key Laboratory of Freshwater Biodiversity Conservation, Yangtze River Fisheries Research Institute, The Ministry of Agriculture and Rural Affairs, Chinese Academy of Fishery Sciences, No. 8, Wudayuan 1st Road, Donghu Hi-tech Development Zone, Wuhan, 430223, China
| | - Xinyuan Li
- Key Laboratory for Animal Nutrition and Feed Science of Hubei Province, Wuhan Polytechnic University, Wuhan, 430023, China
- Key Laboratory of Freshwater Biodiversity Conservation, Yangtze River Fisheries Research Institute, The Ministry of Agriculture and Rural Affairs, Chinese Academy of Fishery Sciences, No. 8, Wudayuan 1st Road, Donghu Hi-tech Development Zone, Wuhan, 430223, China
| | - Lixue Dong
- Key Laboratory of Freshwater Biodiversity Conservation, Yangtze River Fisheries Research Institute, The Ministry of Agriculture and Rural Affairs, Chinese Academy of Fishery Sciences, No. 8, Wudayuan 1st Road, Donghu Hi-tech Development Zone, Wuhan, 430223, China
| | - Hua Wen
- Key Laboratory of Freshwater Biodiversity Conservation, Yangtze River Fisheries Research Institute, The Ministry of Agriculture and Rural Affairs, Chinese Academy of Fishery Sciences, No. 8, Wudayuan 1st Road, Donghu Hi-tech Development Zone, Wuhan, 430223, China
| | - Ming Jiang
- Key Laboratory of Freshwater Biodiversity Conservation, Yangtze River Fisheries Research Institute, The Ministry of Agriculture and Rural Affairs, Chinese Academy of Fishery Sciences, No. 8, Wudayuan 1st Road, Donghu Hi-tech Development Zone, Wuhan, 430223, China
| | - Xing Lu
- Key Laboratory of Freshwater Biodiversity Conservation, Yangtze River Fisheries Research Institute, The Ministry of Agriculture and Rural Affairs, Chinese Academy of Fishery Sciences, No. 8, Wudayuan 1st Road, Donghu Hi-tech Development Zone, Wuhan, 430223, China
| | - Feng Huang
- Key Laboratory for Animal Nutrition and Feed Science of Hubei Province, Wuhan Polytechnic University, Wuhan, 430023, China.
| | - Juan Tian
- Key Laboratory of Freshwater Biodiversity Conservation, Yangtze River Fisheries Research Institute, The Ministry of Agriculture and Rural Affairs, Chinese Academy of Fishery Sciences, No. 8, Wudayuan 1st Road, Donghu Hi-tech Development Zone, Wuhan, 430223, China.
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3
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Rupp AC, Tomlinson AJ, Affinati AH, Yacawych WT, Duensing AM, True C, Lindsley SR, Kirigiti MA, MacKenzie A, Polex-Wolf J, Li C, Knudsen LB, Seeley RJ, Olson DP, Kievit P, Myers MG. Suppression of food intake by Glp1r/Lepr-coexpressing neurons prevents obesity in mouse models. J Clin Invest 2023; 133:e157515. [PMID: 37581939 PMCID: PMC10541203 DOI: 10.1172/jci157515] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Accepted: 08/03/2023] [Indexed: 08/17/2023] Open
Abstract
The adipose-derived hormone leptin acts via its receptor (LepRb) in the brain to control energy balance. A potentially unidentified population of GABAergic hypothalamic LepRb neurons plays key roles in the restraint of food intake and body weight by leptin. To identify markers for candidate populations of LepRb neurons in an unbiased manner, we performed single-nucleus RNA-Seq of enriched mouse hypothalamic LepRb cells, identifying several previously unrecognized populations of hypothalamic LepRb neurons. Many of these populations displayed strong conservation across species, including GABAergic Glp1r-expressing LepRb (LepRbGlp1r) neurons, which expressed more Lepr than other LepRb cell populations. Ablating Lepr from LepRbGlp1r cells provoked hyperphagic obesity without impairing energy expenditure. Similarly, improvements in energy balance caused by Lepr reactivation in GABA neurons of otherwise Lepr-null mice required Lepr expression in GABAergic Glp1r-expressing neurons. Furthermore, restoration of Glp1r expression in LepRbGlp1r neurons in otherwise Glp1r-null mice enabled food intake suppression by the GLP1R agonist, liraglutide. Thus, the conserved GABAergic LepRbGlp1r neuron population plays crucial roles in the suppression of food intake by leptin and GLP1R agonists.
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Affiliation(s)
| | | | | | - Warren T. Yacawych
- Department of Internal Medicine and
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan, USA
| | - Allison M. Duensing
- Department of Internal Medicine and
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan, USA
| | - Cadence True
- Oregon National Primate Research Center, Beaverton, Oregon, USA
| | | | | | | | | | - Chien Li
- Novo Nordisk, Copenhagen, Denmark
| | | | | | - David P. Olson
- Department of Pediatrics, University of Michigan, Ann Arbor, Michigan, USA
| | - Paul Kievit
- Oregon National Primate Research Center, Beaverton, Oregon, USA
| | - Martin G. Myers
- Department of Internal Medicine and
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan, USA
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4
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Uehara K, Santoleri D, Whitlock AEG, Titchenell PM. Insulin Regulation of Hepatic Lipid Homeostasis. Compr Physiol 2023; 13:4785-4809. [PMID: 37358513 PMCID: PMC10760932 DOI: 10.1002/cphy.c220015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/27/2023]
Abstract
The incidence of obesity, insulin resistance, and type II diabetes (T2DM) continues to rise worldwide. The liver is a central insulin-responsive metabolic organ that governs whole-body metabolic homeostasis. Therefore, defining the mechanisms underlying insulin action in the liver is essential to our understanding of the pathogenesis of insulin resistance. During periods of fasting, the liver catabolizes fatty acids and stored glycogen to meet the metabolic demands of the body. In postprandial conditions, insulin signals to the liver to store excess nutrients into triglycerides, cholesterol, and glycogen. In insulin-resistant states, such as T2DM, hepatic insulin signaling continues to promote lipid synthesis but fails to suppress glucose production, leading to hypertriglyceridemia and hyperglycemia. Insulin resistance is associated with the development of metabolic disorders such as cardiovascular and kidney disease, atherosclerosis, stroke, and cancer. Of note, nonalcoholic fatty liver disease (NAFLD), a spectrum of diseases encompassing fatty liver, inflammation, fibrosis, and cirrhosis, is linked to abnormalities in insulin-mediated lipid metabolism. Therefore, understanding the role of insulin signaling under normal and pathologic states may provide insights into preventative and therapeutic opportunities for the treatment of metabolic diseases. Here, we provide a review of the field of hepatic insulin signaling and lipid regulation, including providing historical context, detailed molecular mechanisms, and address gaps in our understanding of hepatic lipid regulation and the derangements under insulin-resistant conditions. © 2023 American Physiological Society. Compr Physiol 13:4785-4809, 2023.
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Affiliation(s)
- Kahealani Uehara
- Institute of Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Dominic Santoleri
- Institute of Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Anna E. Garcia Whitlock
- Institute of Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Department of Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Paul M. Titchenell
- Institute of Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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5
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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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6
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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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7
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Wang Y, Yu W, Li S, Guo D, He J, Wang Y. Acetyl-CoA Carboxylases and Diseases. Front Oncol 2022; 12:836058. [PMID: 35359351 PMCID: PMC8963101 DOI: 10.3389/fonc.2022.836058] [Citation(s) in RCA: 48] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 02/10/2022] [Indexed: 12/28/2022] Open
Abstract
Acetyl-CoA carboxylases (ACCs) are enzymes that catalyze the carboxylation of acetyl-CoA to produce malonyl-CoA. In mammals, ACC1 and ACC2 are two members of ACCs. ACC1 localizes in the cytosol and acts as the first and rate-limiting enzyme in the de novo fatty acid synthesis pathway. ACC2 localizes on the outer membrane of mitochondria and produces malonyl-CoA to regulate the activity of carnitine palmitoyltransferase 1 (CPT1) that involves in the β-oxidation of fatty acid. Fatty acid synthesis is central in a myriad of physiological and pathological conditions. ACC1 is the major member of ACCs in mammalian, mountains of documents record the roles of ACC1 in various diseases, such as cancer, diabetes, obesity. Besides, acetyl-CoA and malonyl-CoA are cofactors in protein acetylation and malonylation, respectively, so that the manipulation of acetyl-CoA and malonyl-CoA by ACC1 can also markedly influence the profile of protein post-translational modifications, resulting in alternated biological processes in mammalian cells. In the review, we summarize our understandings of ACCs, including their structural features, regulatory mechanisms, and roles in diseases. ACC1 has emerged as a promising target for diseases treatment, so that the specific inhibitors of ACC1 for diseases treatment are also discussed.
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Affiliation(s)
- Yu Wang
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science of Technology, Wuhan, China
| | - Weixing Yu
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science of Technology, Wuhan, China
| | - Sha Li
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science of Technology, Wuhan, China
| | - Dingyuan Guo
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science of Technology, Wuhan, China
| | - Jie He
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science of Technology, Wuhan, China
- Department of Neurosurgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yugang Wang
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science of Technology, Wuhan, China
- Cell Architecture Research Center, Huazhong University of Science and Technology, Wuhan, China
- *Correspondence: Yugang Wang,
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8
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Ritterhoff J, McMillen TS, Villet O, Young S, Kolwicz SC, Senn T, Caudal A, Tian R. Increasing fatty acid oxidation elicits a sex-dependent response in failing mouse hearts. J Mol Cell Cardiol 2021; 158:1-10. [PMID: 33989657 PMCID: PMC8405556 DOI: 10.1016/j.yjmcc.2021.05.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 05/06/2021] [Accepted: 05/07/2021] [Indexed: 01/12/2023]
Abstract
BACKGROUND Reduced fatty acid oxidation (FAO) is a hallmark of metabolic remodeling in heart failure. Enhancing mitochondrial long-chain fatty acid uptake by Acetyl-CoA carboxylase 2 (ACC2) deletion increases FAO and prevents cardiac dysfunction during chronic stresses, but therapeutic efficacy of this approach has not been determined. METHODS Male and female ACC2 f/f-MCM (ACC2KO) and their respective littermate controls were subjected to chronic pressure overload by TAC surgery. Tamoxifen injection 3 weeks after TAC induced ACC2 deletion and increased FAO in ACC2KO mice with pathological hypertrophy. RESULTS ACC2 deletion in mice with pre-existing cardiac pathology promoted FAO in female and male hearts, but improved cardiac function only in female mice. In males, pressure overload caused a downregulation in the mitochondrial oxidative function. Stimulating FAO by ACC2 deletion caused unproductive acyl-carnitine accumulation, which failed to improve cardiac energetics. In contrast, mitochondrial oxidative capacity was sustained in female pressure overloaded hearts and ACC2 deletion improved myocardial energetics. Mechanistically, we revealed a sex-dependent regulation of PPARα signaling pathway in heart failure, which accounted for the differential response to ACC2 deletion. CONCLUSION Metabolic remodeling in the failing heart is sex-dependent which could determine the response to metabolic intervention. The findings suggest that both mitochondrial oxidative capacity and substrate preference should be considered for metabolic therapy of heart failure.
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Affiliation(s)
- Julia Ritterhoff
- Mitochondria and Metabolism Center, Department of Anesthesiology and Pain Medicine, University of Washington, Republican Street 850, 98109 Seattle, WA, USA
| | - Timothy S. McMillen
- Mitochondria and Metabolism Center, Department of Anesthesiology and Pain Medicine, University of Washington, Republican Street 850, 98109 Seattle, WA, USA
| | - Outi Villet
- Mitochondria and Metabolism Center, Department of Anesthesiology and Pain Medicine, University of Washington, Republican Street 850, 98109 Seattle, WA, USA
| | - Sara Young
- Mitochondria and Metabolism Center, Department of Anesthesiology and Pain Medicine, University of Washington, Republican Street 850, 98109 Seattle, WA, USA
| | - Stephen C. Kolwicz
- Mitochondria and Metabolism Center, Department of Anesthesiology and Pain Medicine, University of Washington, Republican Street 850, 98109 Seattle, WA, USA.,Heart and Muscle Metabolism Laboratory, Health and Exercise Physiology, Ursinus College, Collegeville, PA 19426, USA
| | - Taurence Senn
- Department of Medicinal Chemistry, School of Pharmacy, University of Washington, H172 Health Science Building, 98195 Seattle, WA, USA
| | - Arianne Caudal
- Mitochondria and Metabolism Center, Department of Anesthesiology and Pain Medicine, University of Washington, Republican Street 850, 98109 Seattle, WA, USA
| | - Rong Tian
- Mitochondria and Metabolism Center, Department of Anesthesiology and Pain Medicine, University of Washington, Republican Street 850, 98109 Seattle, WA, USA.,Corresponding author at: Mitochondria and Metabolism Center, University of Washington School of Medicine, 850 Republican Street, Seattle, WA 98109
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9
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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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10
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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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11
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Catlin NR, Bowman CJ, Campion SN, Davenport SD, Esler WP, Kumpf SW, Lewis EM, Nowland WS, Ross TT, Stedman DS, Stethem C, Cappon GD. Inhibition of ACC causes malformations in rats and rabbits: comparison of mammalian findings and alternative assays. Toxicol Sci 2020; 179:183-194. [PMID: 33247737 DOI: 10.1093/toxsci/kfaa169] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Acetyl-CoA carboxylase (ACC) is an enzyme within the de novo lipogenesis (DNL) pathway and plays a role in regulating lipid metabolism. Pharmacologic ACC inhibition has been an area of interest for multiple potential indications including oncology, acne vulgaris, metabolic diseases such as type 2 diabetes mellitus, and non-alcoholic fatty liver disease/non-alcoholic steatohepatitis. A critical role for ACC in de novo synthesis of long-chain fatty acids during fetal development has been demonstrated in studies in mice lacking Acc1, where the absence of Acc1 results in early embryonic lethality. Following positive predictions of developmental toxicity in alternative in vitro assays (positive in murine embryonic stem cell [mESC] assay and rat whole embryo culture, but negative in zebrafish), developmental toxicity (growth retardation and dysmorphogenesis associated with disrupted midline fusion) was observed with the oral administration of the dual ACC1 and 2 inhibitor, PF-05175157, in Sprague Dawley rats and New Zealand White rabbits. The results of these studies are presented here to make comparisons across the assays, as well as mechanistic insights from the mESC assay demonstrating high ACC expression in the mESC and that ACC induced developmental toxicity can be rescued with palmitic acid providing supportive evidence for DNL pathway inhibition as the underlying mechanism. Ultimately, while the battery of alternative approaches and weight-of-evidence case were useful for hazard identification, the embryo-fetal development studies were necessary to inform the risk assessment on the adverse fetal response, as malformations and/or embryo fetal lethality were limited to doses that caused near complete inhibition of DNL.
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Affiliation(s)
- Natasha R Catlin
- Drug Safety Research and Development, Pfizer Worldwide Research & Development, Groton, CT, USA
| | - Christopher J Bowman
- Drug Safety Research and Development, Pfizer Worldwide Research & Development, Groton, CT, USA
| | - Sarah N Campion
- Drug Safety Research and Development, Pfizer Worldwide Research & Development, Groton, CT, USA
| | - Scott D Davenport
- Drug Safety Research and Development, Pfizer Worldwide Research & Development, Groton, CT, USA
| | - William P Esler
- Internal Medicine Research Unit, Pfizer Worldwide Research & Development, Cambridge, MA, USA
| | - Steven W Kumpf
- Drug Safety Research and Development, Pfizer Worldwide Research & Development, Groton, CT, USA
| | - Elise M Lewis
- Charles River Laboratories, Inc, Safety Assessment, Horsham, PA, USA
| | - William S Nowland
- Drug Safety Research and Development, Pfizer Worldwide Research & Development, Groton, CT, USA
| | - Trenton T Ross
- Internal Medicine Research Unit, Pfizer Worldwide Research & Development, Cambridge, MA, USA
| | - Donald S Stedman
- Drug Safety Research and Development, Pfizer Worldwide Research & Development, Groton, CT, USA
| | - Christine Stethem
- Drug Safety Research and Development, Pfizer Worldwide Research & Development, Groton, CT, USA
| | - Gregg D Cappon
- Drug Safety Research and Development, Pfizer Worldwide Research & Development, Groton, CT, USA
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12
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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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13
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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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14
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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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15
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Matsumoto M, Yashiro H, Ogino H, Aoyama K, Nambu T, Nakamura S, Nishida M, Wang X, Erion DM, Kaneko M. Acetyl-CoA carboxylase 1 and 2 inhibition ameliorates steatosis and hepatic fibrosis in a MC4R knockout murine model of nonalcoholic steatohepatitis. PLoS One 2020; 15:e0228212. [PMID: 31990961 PMCID: PMC6986730 DOI: 10.1371/journal.pone.0228212] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Accepted: 01/10/2020] [Indexed: 12/16/2022] Open
Abstract
Acetyl-CoA carboxylase (ACC) catalyzes the rate-limiting step in de novo lipogenesis, which is increased in the livers of patients with nonalcoholic steatohepatitis. GS-0976 (firsocostat), an inhibitor of isoforms ACC1 and ACC2, reduced hepatic steatosis and serum fibrosis biomarkers such as tissue inhibitor of metalloproteinase 1 in patients with nonalcoholic steatohepatitis in a randomized controlled trial, although the impact of this improvement on fibrosis has not fully been evaluated in preclinical models. Here, we used Western diet-fed melanocortin 4 receptor-deficient mice that have similar phenotypes to nonalcoholic steatohepatitis patients including progressively developed hepatic steatosis as well as fibrosis. We evaluated the effects of ACC1/2 inhibition on hepatic fibrosis. After the confirmation of significant hepatic fibrosis with a 13-week pre-feeding, GS-0976 (4 and 16 mg/kg/day) treatment for 9 weeks lowered malonyl-CoA and triglyceride content in the liver and improved steatosis, histologically. Furthermore, GS-0976 reduced the histological area of hepatic fibrosis, hydroxyproline content, mRNA expression level of type I collagen in the liver, and plasma tissue metalloproteinase inhibitor 1, suggesting an improvement of hepatic fibrosis. The treatment with GS-0976 was also accompanied by reductions of plasma ALT and AST levels. These data demonstrate that improvement of hepatic lipid metabolism by ACC1/2 inhibition could be a new option to suppress fibrosis progression as well as to improve hepatic steatosis in nonalcoholic steatohepatitis.
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Affiliation(s)
- Mitsuharu Matsumoto
- Department of Integrated Biology, Axcelead Drug Discovery Partners, Inc., Fujisawa, Kanagawa, Japan
- * E-mail:
| | - Hiroaki Yashiro
- Gastroenterology Drug Discovery Unit, Takeda Pharmaceutical Company Limited, Cambridge, Massachusetts, United States of America
| | - Hitomi Ogino
- Department of Integrated Biology, Axcelead Drug Discovery Partners, Inc., Fujisawa, Kanagawa, Japan
| | - Kazunobu Aoyama
- Department of Drug Disposition & Analysis, Axcelead Drug Discovery Partners, Inc., Fujisawa, Kanagawa, Japan
| | - Tadahiro Nambu
- Department of Nonclinical Safety Research, Axcelead Drug Discovery Partners, Inc., Fujisawa, Kanagawa, Japan
| | - Sayuri Nakamura
- Department of Nonclinical Safety Research, Axcelead Drug Discovery Partners, Inc., Fujisawa, Kanagawa, Japan
| | - Mayumi Nishida
- Department of Integrated Biology, Axcelead Drug Discovery Partners, Inc., Fujisawa, Kanagawa, Japan
| | - Xiaolun Wang
- Gastroenterology Drug Discovery Unit, Takeda Pharmaceutical Company Limited, Cambridge, Massachusetts, United States of America
| | - Derek M. Erion
- Gastroenterology Drug Discovery Unit, Takeda Pharmaceutical Company Limited, Cambridge, Massachusetts, United States of America
| | - Manami Kaneko
- Department of Integrated Biology, Axcelead Drug Discovery Partners, Inc., Fujisawa, Kanagawa, Japan
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16
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Ritterhoff J, Young S, Villet O, Shao D, Neto FC, Bettcher LF, Hsu YWA, Kolwicz SC, Raftery D, Tian R. Metabolic Remodeling Promotes Cardiac Hypertrophy by Directing Glucose to Aspartate Biosynthesis. Circ Res 2020; 126:182-196. [PMID: 31709908 PMCID: PMC8448129 DOI: 10.1161/circresaha.119.315483] [Citation(s) in RCA: 135] [Impact Index Per Article: 33.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
RATIONALE Hypertrophied hearts switch from mainly using fatty acids (FAs) to an increased reliance on glucose for energy production. It has been shown that preserving FA oxidation (FAO) prevents the pathological shift of substrate preference, preserves cardiac function and energetics, and reduces cardiomyocyte hypertrophy during cardiac stresses. However, it remains elusive whether substrate metabolism regulates cardiomyocyte hypertrophy directly or via a secondary effect of improving cardiac energetics. OBJECTIVE The goal of this study was to determine the mechanisms of how preservation of FAO prevents the hypertrophic growth of cardiomyocytes. METHODS AND RESULTS We cultured adult rat cardiomyocytes in a medium containing glucose and mixed-chain FAs and induced pathological hypertrophy by phenylephrine. Phenylephrine-induced hypertrophy was associated with increased glucose consumption and higher intracellular aspartate levels, resulting in increased synthesis of nucleotides, RNA, and proteins. These changes could be prevented by increasing FAO via deletion of ACC2 (acetyl-CoA-carboxylase 2) in phenylephrine-stimulated cardiomyocytes and in pressure overload-induced cardiac hypertrophy in vivo. Furthermore, aspartate supplementation was sufficient to reverse the antihypertrophic effect of ACC2 deletion demonstrating a causal role of elevated aspartate level in cardiomyocyte hypertrophy. 15N and 13C stable isotope tracing revealed that glucose but not glutamine contributed to increased biosynthesis of aspartate, which supplied nitrogen for nucleotide synthesis during cardiomyocyte hypertrophy. CONCLUSIONS Our data show that increased glucose consumption is required to support aspartate synthesis that drives the increase of biomass during cardiac hypertrophy. Preservation of FAO prevents the shift of metabolic flux into the anabolic pathway and maintains catabolic metabolism for energy production, thus preventing cardiac hypertrophy and improving myocardial energetics.
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Affiliation(s)
- Julia Ritterhoff
- From the Department of Anesthesiology and Pain Medicine (J.R., S.Y., O.V., D.S., Y.-W.A.H., S.C.K., R.T.), Mitochondria and Metabolism Center, University of Washington, Seattle
| | - Sara Young
- From the Department of Anesthesiology and Pain Medicine (J.R., S.Y., O.V., D.S., Y.-W.A.H., S.C.K., R.T.), Mitochondria and Metabolism Center, University of Washington, Seattle
| | - Outi Villet
- From the Department of Anesthesiology and Pain Medicine (J.R., S.Y., O.V., D.S., Y.-W.A.H., S.C.K., R.T.), Mitochondria and Metabolism Center, University of Washington, Seattle
| | - Dan Shao
- From the Department of Anesthesiology and Pain Medicine (J.R., S.Y., O.V., D.S., Y.-W.A.H., S.C.K., R.T.), Mitochondria and Metabolism Center, University of Washington, Seattle
| | - F Carnevale Neto
- Department of Anesthesiology and Pain Medicine, Northwest Metabolomics Research Center (F.C.N., L.F.B., D.R.), Mitochondria and Metabolism Center, University of Washington, Seattle
| | - Lisa F Bettcher
- Department of Anesthesiology and Pain Medicine, Northwest Metabolomics Research Center (F.C.N., L.F.B., D.R.), Mitochondria and Metabolism Center, University of Washington, Seattle
| | - Yun-Wei A Hsu
- From the Department of Anesthesiology and Pain Medicine (J.R., S.Y., O.V., D.S., Y.-W.A.H., S.C.K., R.T.), Mitochondria and Metabolism Center, University of Washington, Seattle
| | - Stephen C Kolwicz
- From the Department of Anesthesiology and Pain Medicine (J.R., S.Y., O.V., D.S., Y.-W.A.H., S.C.K., R.T.), Mitochondria and Metabolism Center, University of Washington, Seattle
| | - Daniel Raftery
- Department of Anesthesiology and Pain Medicine, Northwest Metabolomics Research Center (F.C.N., L.F.B., D.R.), Mitochondria and Metabolism Center, University of Washington, Seattle
| | - Rong Tian
- From the Department of Anesthesiology and Pain Medicine (J.R., S.Y., O.V., D.S., Y.-W.A.H., S.C.K., R.T.), Mitochondria and Metabolism Center, University of Washington, Seattle
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17
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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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18
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Chen Z, Yu Y, Cai J, Li H. Emerging Molecular Targets for Treatment of Nonalcoholic Fatty Liver Disease. Trends Endocrinol Metab 2019; 30:903-914. [PMID: 31597607 DOI: 10.1016/j.tem.2019.08.006] [Citation(s) in RCA: 78] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2019] [Revised: 08/14/2019] [Accepted: 08/16/2019] [Indexed: 12/12/2022]
Abstract
In parallel with the obesity epidemic, nonalcoholic fatty liver disease (NAFLD) has emerged as the most common chronic liver disease worldwide. Disequilibrium of lipid metabolism and the subsequent metabolic-stress-induced inflammation are believed to be central in the pathogenesis of NAFLD. Of note, metabolic inflammation is primarily mediated by innate immune signaling, which is increasingly recognized as a driving force in NAFLD progression. Currently, a series of agents targeting one or more of these pathomechanisms have shown encouraging results in preclinical models and clinical trials. This review summarizes the emerging molecular targets involved in signaling in the lipid metabolism and innate immunity aspects of NAFLD, focusing on their mechanistic roles and translational potentials.
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Affiliation(s)
- Ze Chen
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan 430060, China; Institute of Model Animals of Wuhan University, Wuhan 430072, China
| | - Yao Yu
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan 430060, China; Institute of Model Animals of Wuhan University, Wuhan 430072, China
| | - Jingjing Cai
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan 430060, China; Institute of Model Animals of Wuhan University, Wuhan 430072, China; Department of Cardiology, The Third Xiangya Hospital, Central South University, Changsha 410013, China.
| | - Hongliang Li
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan 430060, China; Institute of Model Animals of Wuhan University, Wuhan 430072, China; Basic Medical School, Wuhan University, Wuhan 430071, China.
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19
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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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20
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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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21
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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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22
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Barnes NE, Mendoza KM, Strasburg GM, Velleman SG, Reed KM. Thermal challenge alters the transcriptional profile of the breast muscle in turkey poults. Poult Sci 2019; 98:74-91. [PMID: 30239949 DOI: 10.3382/ps/pey401] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 08/08/2018] [Indexed: 12/25/2022] Open
Abstract
Extremes in temperature represent environmental stressors that impact the well-being and economic value of poultry. As homeotherms, young poultry with immature thermoregulatory systems are especially susceptible to thermal extremes. Genetic variation and differences in gene expression resulting from selection for production traits, likely contribute to thermal stress response. This study was designed to investigate in vivo transcriptional changes in the breast muscle of young turkey poults from an unselected randombred line and one selected for 16 wk body weight under hot and cold thermal challenge. Newly hatched turkey poults were brooded for 3 d at one of 3 temperatures: control (35°C), cold (31°C), or hot (39°C). Samples of the pectoralis major were harvested and subjected to deep RNA sequencing. Significant differential gene expression was observed in both growth-selected and randombred birds at both temperature extremes when compared to control-brooded poults. Growth-selected birds responded to thermal stress through changes in genes predicted to have downstream transcriptional effects and that would result in reduced muscle growth. Slower growing randombred birds responded to thermal stress through modulation of lipid-related genes, suggesting reduction in lipid storage, transport, and synthesis, consistent with changes in energy metabolism required to maintain body temperature.
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Affiliation(s)
- Natalie E Barnes
- Department of Veterinary and Biomedical Sciences, University of Minnesota, St. Paul, MN 55108, USA
| | - Kristelle M Mendoza
- Department of Veterinary and Biomedical Sciences, University of Minnesota, St. Paul, MN 55108, USA
| | - Gale M Strasburg
- Department of Food Science and Human Nutrition, Michigan State University, East Lansing, MI 48824, USA
| | - Sandra G Velleman
- Department of Animal Sciences, The Ohio State University/Ohio Agricultural Research and Development Center, Wooster, OH 44691, USA
| | - Kent M Reed
- Department of Veterinary and Biomedical Sciences, University of Minnesota, St. Paul, MN 55108, USA
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Geng T, Liu Y, Xu Y, Jiang Y, Zhang N, Wang Z, Carmichael GG, Taylor HS, Li D, Huang Y. H19 lncRNA Promotes Skeletal Muscle Insulin Sensitivity in Part by Targeting AMPK. Diabetes 2018; 67:2183-2198. [PMID: 30201684 PMCID: PMC6198334 DOI: 10.2337/db18-0370] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Accepted: 08/24/2018] [Indexed: 12/12/2022]
Abstract
Skeletal muscle plays a pivotal role in regulating systemic glucose homeostasis in part through the conserved cellular energy sensor AMPK. AMPK activation increases glucose uptake, lipid oxidation, and mitochondrial biogenesis, leading to enhanced muscle insulin sensitivity and whole-body energy metabolism. Here we show that the muscle-enriched H19 long noncoding RNA (lncRNA) acts to enhance muscle insulin sensitivity, at least in part, by activating AMPK. We identify the atypical dual-specificity phosphatase DUSP27/DUPD1 as a potentially important downstream effector of H19. We show that DUSP27, which is highly expressed in muscle with previously unknown physiological function, interacts with and activates AMPK in muscle cells. Consistent with decreased H19 expression in the muscle of insulin-resistant human subjects and rodents, mice with genetic H19 ablation exhibit muscle insulin resistance. Furthermore, a high-fat diet downregulates muscle H19 via both posttranscriptional and epigenetic mechanisms. Our results uncover an evolutionarily conserved, highly expressed lncRNA as an important regulator of muscle insulin sensitivity.
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Affiliation(s)
- Tingting Geng
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Yale School of Medicine, New Haven, CT
- Department of Endocrinology, First Affiliated Hospital of Xi'an Jiaotong University School of Medicine, Xi'an, Shaanxi, People's Republic of China
| | - Ya Liu
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Yale School of Medicine, New Haven, CT
- Department of Veterinary Medicine, College of Animal Science and Technology, Anhui Agricultural University, Hefei, Anhui, People's Republic of China
| | - Yetao Xu
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Yale School of Medicine, New Haven, CT
- Department of Obstetrics and Gynecology, First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, People's Republic of China
| | - Ying Jiang
- Department of Obstetrics, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, People's Republic of China
| | - Na Zhang
- Department of Genetics and Genome Sciences, University of Connecticut Health Center, Farmington, CT
| | - Zhangsheng Wang
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Yale School of Medicine, New Haven, CT
- Department of Cardiology, Fifth People's Hospital of Shanghai, Fudan University, Shanghai, People's Republic of China
| | - Gordon G Carmichael
- Department of Genetics and Genome Sciences, University of Connecticut Health Center, Farmington, CT
| | - Hugh S Taylor
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Yale School of Medicine, New Haven, CT
| | - Da Li
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Yale School of Medicine, New Haven, CT
- Center of Reproductive Medicine, Department of Obstetrics and Gynecology, Shengjing Hospital, China Medical University, Shenyang, Liaoning, People's Republic of China
| | - Yingqun Huang
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Yale School of Medicine, New Haven, CT
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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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26
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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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27
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Stüve P, Minarrieta L, Erdmann H, Arnold-Schrauf C, Swallow M, Guderian M, Krull F, Hölscher A, Ghorbani P, Behrends J, Abraham WR, Hölscher C, Sparwasser TD, Berod L. De Novo Fatty Acid Synthesis During Mycobacterial Infection Is a Prerequisite for the Function of Highly Proliferative T Cells, But Not for Dendritic Cells or Macrophages. Front Immunol 2018; 9:495. [PMID: 29675017 PMCID: PMC5895737 DOI: 10.3389/fimmu.2018.00495] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Accepted: 02/26/2018] [Indexed: 12/21/2022] Open
Abstract
Mycobacterium tuberculosis (Mtb), the causative agent of human tuberculosis, is able to efficiently manipulate the host immune system establishing chronic infection, yet the underlying mechanisms of immune evasion are not fully understood. Evidence suggests that this pathogen interferes with host cell lipid metabolism to ensure its persistence. Fatty acid metabolism is regulated by acetyl-CoA carboxylase (ACC) 1 and 2; both isoforms catalyze the conversion of acetyl-CoA into malonyl-CoA, but have distinct roles. ACC1 is located in the cytosol, where it regulates de novo fatty acid synthesis (FAS), while ACC2 is associated with the outer mitochondrial membrane, regulating fatty acid oxidation (FAO). In macrophages, mycobacteria induce metabolic changes that lead to the cytosolic accumulation of lipids. This reprogramming impairs macrophage activation and contributes to chronic infection. In dendritic cells (DCs), FAS has been suggested to underlie optimal cytokine production and antigen presentation, but little is known about the metabolic changes occurring in DCs upon mycobacterial infection and how they affect the outcome of the immune response. We therefore determined the role of fatty acid metabolism in myeloid cells and T cells during Mycobacterium bovis BCG or Mtb infection, using novel genetic mouse models that allow cell-specific deletion of ACC1 and ACC2 in DCs, macrophages, or T cells. Our results demonstrate that de novo FAS is induced in DCs and macrophages upon M. bovis BCG infection. However, ACC1 expression in DCs and macrophages is not required to control mycobacteria. Similarly, absence of ACC2 did not influence the ability of DCs and macrophages to cope with infection. Furthermore, deletion of ACC1 in DCs or macrophages had no effect on systemic pro-inflammatory cytokine production or T cell priming, suggesting that FAS is dispensable for an intact innate response against mycobacteria. In contrast, mice with a deletion of ACC1 specifically in T cells fail to generate efficient T helper 1 responses and succumb early to Mtb infection. In summary, our results reveal ACC1-dependent FAS as a crucial mechanism in T cells, but not DCs or macrophages, to fight against mycobacterial infection.
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Affiliation(s)
- Philipp Stüve
- Institute of Infection Immunology, TWINCORE, Centre for Experimental and Clinical Infection Research, A Joint Venture Between the Medical School Hannover (MHH) and the Helmholtz Centre for Infection Research (HZI), Hannover, Germany
| | - Lucía Minarrieta
- Institute of Infection Immunology, TWINCORE, Centre for Experimental and Clinical Infection Research, A Joint Venture Between the Medical School Hannover (MHH) and the Helmholtz Centre for Infection Research (HZI), Hannover, Germany
| | - Hanna Erdmann
- Infection Immunology, Research Center Borstel, Borstel, Germany
| | - Catharina Arnold-Schrauf
- Institute of Infection Immunology, TWINCORE, Centre for Experimental and Clinical Infection Research, A Joint Venture Between the Medical School Hannover (MHH) and the Helmholtz Centre for Infection Research (HZI), Hannover, Germany
| | - Maxine Swallow
- Institute of Infection Immunology, TWINCORE, Centre for Experimental and Clinical Infection Research, A Joint Venture Between the Medical School Hannover (MHH) and the Helmholtz Centre for Infection Research (HZI), Hannover, Germany
| | - Melanie Guderian
- Institute of Infection Immunology, TWINCORE, Centre for Experimental and Clinical Infection Research, A Joint Venture Between the Medical School Hannover (MHH) and the Helmholtz Centre for Infection Research (HZI), Hannover, Germany
| | - Freyja Krull
- Institute of Infection Immunology, TWINCORE, Centre for Experimental and Clinical Infection Research, A Joint Venture Between the Medical School Hannover (MHH) and the Helmholtz Centre for Infection Research (HZI), Hannover, Germany
| | | | - Peyman Ghorbani
- Institute of Infection Immunology, TWINCORE, Centre for Experimental and Clinical Infection Research, A Joint Venture Between the Medical School Hannover (MHH) and the Helmholtz Centre for Infection Research (HZI), Hannover, Germany
| | - Jochen Behrends
- Core Facility Fluorescence Cytometry, Research Center Borstel, Borstel, Germany
| | - Wolf-Rainer Abraham
- Department of Chemical Microbiology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | | | - Tim D Sparwasser
- Institute of Infection Immunology, TWINCORE, Centre for Experimental and Clinical Infection Research, A Joint Venture Between the Medical School Hannover (MHH) and the Helmholtz Centre for Infection Research (HZI), Hannover, Germany
| | - Luciana Berod
- Institute of Infection Immunology, TWINCORE, Centre for Experimental and Clinical Infection Research, A Joint Venture Between the Medical School Hannover (MHH) and the Helmholtz Centre for Infection Research (HZI), Hannover, Germany
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28
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Cytosolic carnitine acetyltransferase as a source of cytosolic acetyl-CoA: a possible mechanism for regulation of cardiac energy metabolism. Biochem J 2018; 475:959-976. [PMID: 29438065 DOI: 10.1042/bcj20170823] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Revised: 02/05/2018] [Accepted: 02/05/2018] [Indexed: 12/30/2022]
Abstract
The role of carnitine acetyltransferase (CrAT) in regulating cardiac energy metabolism is poorly understood. CrAT modulates mitochondrial acetyl-CoA/CoA (coenzyme A) ratios, thus regulating pyruvate dehydrogenase activity and glucose oxidation. Here, we propose that cardiac CrAT also provides cytosolic acetyl-CoA for the production of malonyl-CoA, a potent inhibitor of fatty acid oxidation. We show that in the murine cardiomyocyte cytosol, reverse CrAT activity (RCrAT, producing acetyl-CoA) is higher compared with the liver, which primarily uses ATP-citrate lyase to produce cytosolic acetyl-CoA for lipogenesis. The heart displayed a lower RCrAT Km for CoA compared with the liver. Furthermore, cytosolic RCrAT accounted for 4.6 ± 0.7% of total activity in heart tissue and 12.7 ± 0.2% in H9C2 cells, while highly purified heart cytosolic fractions showed significant CrAT protein levels. To investigate the relationship between CrAT and acetyl-CoA carboxylase (ACC), the cytosolic enzyme catalyzing malonyl-CoA production from acetyl-CoA, we studied ACC2-knockout mouse hearts which showed decreased CrAT protein levels and activity, associated with increased palmitate oxidation and acetyl-CoA/CoA ratio compared with controls. Conversely, feeding mice a high-fat diet for 10 weeks increased cardiac CrAT protein levels and activity, associated with a reduced acetyl-CoA/CoA ratio and glucose oxidation. These data support the presence of a cytosolic CrAT with a low Km for CoA, favoring the formation of cytosolic acetyl-CoA, providing an additional source to the classical ATP-citrate lyase pathway, and that there is an inverse relation between CrAT and the ratio of acetyl-CoA/CoA as evident in conditions affecting the regulation of cardiac energy metabolism.
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29
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Samuel VT, Shulman GI. Nonalcoholic Fatty Liver Disease as a Nexus of Metabolic and Hepatic Diseases. Cell Metab 2018; 27:22-41. [PMID: 28867301 PMCID: PMC5762395 DOI: 10.1016/j.cmet.2017.08.002] [Citation(s) in RCA: 452] [Impact Index Per Article: 75.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 07/01/2017] [Accepted: 08/01/2017] [Indexed: 12/15/2022]
Abstract
NAFLD is closely linked with hepatic insulin resistance. Accumulation of hepatic diacylglycerol activates PKC-ε, impairing insulin receptor activation and insulin-stimulated glycogen synthesis. Peripheral insulin resistance indirectly influences hepatic glucose and lipid metabolism by increasing flux of substrates that promote lipogenesis (glucose and fatty acids) and gluconeogenesis (glycerol and fatty acid-derived acetyl-CoA, an allosteric activator of pyruvate carboxylase). Weight loss with diet or bariatric surgery effectively treats NAFLD, but drugs specifically approved for NAFLD are not available. Some new pharmacological strategies act broadly to alter energy balance or influence pathways that contribute to NAFLD (e.g., agonists for PPAR γ, PPAR α/δ, FXR and analogs for FGF-21, and GLP-1). Others specifically inhibit key enzymes involved in lipid synthesis (e.g., mitochondrial pyruvate carrier, acetyl-CoA carboxylase, stearoyl-CoA desaturase, and monoacyl- and diacyl-glycerol transferases). Finally, a novel class of liver-targeted mitochondrial uncoupling agents increases hepatocellular energy expenditure, reversing the metabolic and hepatic complications of NAFLD.
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Affiliation(s)
- Varman T Samuel
- Department of Medicine, Yale University School of Medicine, New Haven, CT 06510, USA; Veterans Affairs Medical Center, West Haven, CT 06516, USA.
| | - Gerald I Shulman
- Department of Medicine, Yale University School of Medicine, New Haven, CT 06510, USA; Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT 06510, USA; Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, CT 06510, USA.
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30
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Joseph JS, Ayeleso AO, Mukwevho E. Role of exercise-induced calmodulin protein kinase (CaMK)II activation in the regulation of omega-6 fatty acids and lipid metabolism genes in rat skeletal muscle. Physiol Res 2017; 66:969-977. [PMID: 28937250 DOI: 10.33549/physiolres.933509] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Activation of calmodulin dependent protein kinase (CaMK)II by exercise is beneficial in controlling membrane lipids associated with type 2 diabetes and obesity. Regulation of lipid metabolism is crucial in the improvement of type 2 diabetes and obesity associated symptoms. The role of CaMKII in membrane associated lipid metabolism was the focus of this study. Five to six weeks old male Wistar rats were used in this study. GC×GC-TOFMS technique was used to determine the levels of polyunsaturated fatty acids (linoleic acid, arachidonic acid and 11,14-eicosadienoic acid). Carnitine palmitoyltransferase (Cpt-1) and acetyl-CoA carboxylase (Acc-1) genes expression were assessed using quantitative real time PCR (qPCR). From the results, CaMKII activation by exercise increased the levels of arachidonic acid and 11,14-eicosadienoic acid while a decrease in the level of linolenic acid was observed in the skeletal muscle. The results indicated that exercise-induced CaMKII activation increased CPT-1 expression and decreased ACC-1 expression in rat skeletal muscle. All the observed increases with activation of CaMKII by exercise were aborted when KN93, an inhibitor of CaMKII was injected in exercising rats. This study demonstrated that CaMKII activation by exercise regulated lipid metabolism. This study suggests that CaMKII can be a vital target of therapeutic approach in the management of diseases such as type 2 diabetes and obesity that have increased to epidemic proportions recently.
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Affiliation(s)
- J S Joseph
- Department of Biochemistry, University of Johannesburg, South Africa, Department of Biological Sciences, North-West University, Mafikeng Campus, Mmabatho, South Africa.
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31
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Kim CW, Addy C, Kusunoki J, Anderson NN, Deja S, Fu X, Burgess SC, Li C, Ruddy M, Chakravarthy M, Previs S, Milstein S, Fitzgerald K, Kelley DE, Horton JD. Acetyl CoA Carboxylase Inhibition Reduces Hepatic Steatosis but Elevates Plasma Triglycerides in Mice and Humans: A Bedside to Bench Investigation. Cell Metab 2017; 26:394-406.e6. [PMID: 28768177 PMCID: PMC5603267 DOI: 10.1016/j.cmet.2017.07.009] [Citation(s) in RCA: 229] [Impact Index Per Article: 32.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Revised: 06/16/2017] [Accepted: 07/14/2017] [Indexed: 12/13/2022]
Abstract
Inhibiting lipogenesis prevents hepatic steatosis in rodents with insulin resistance. To determine if reducing lipogenesis functions similarly in humans, we developed MK-4074, a liver-specific inhibitor of acetyl-CoA carboxylase (ACC1) and (ACC2), enzymes that produce malonyl-CoA for fatty acid synthesis. MK-4074 administered to subjects with hepatic steatosis for 1 month lowered lipogenesis, increased ketones, and reduced liver triglycerides by 36%. Unexpectedly, MK-4074 increased plasma triglycerides by 200%. To further investigate, mice that lack ACC1 and ACC2 in hepatocytes (ACC dLKO) were generated. Deletion of ACCs decreased polyunsaturated fatty acid (PUFA) concentrations in liver due to reduced malonyl-CoA, which is required for elongation of essential fatty acids. PUFA deficiency induced SREBP-1c, which increased GPAT1 expression and VLDL secretion. PUFA supplementation or siRNA-mediated knockdown of GPAT1 normalized plasma triglycerides. Thus, inhibiting lipogenesis in humans reduced hepatic steatosis, but inhibiting ACC resulted in hypertriglyceridemia due to activation of SREBP-1c and increased VLDL secretion.
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Affiliation(s)
- Chai-Wan Kim
- Departments of Internal Medicine and Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046, USA
| | - Carol Addy
- MRL, 2000 Galloping Hill Road, Kenilworth, NJ 07033, USA
| | - Jun Kusunoki
- MRL, 2000 Galloping Hill Road, Kenilworth, NJ 07033, USA
| | - Norma N Anderson
- Departments of Internal Medicine and Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046, USA
| | - Stanislaw Deja
- Advanced Imaging Research Center and Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Xiaorong Fu
- Advanced Imaging Research Center and Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Shawn C Burgess
- Advanced Imaging Research Center and Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Cai Li
- MRL, 2000 Galloping Hill Road, Kenilworth, NJ 07033, USA
| | - Marcie Ruddy
- MRL, 2000 Galloping Hill Road, Kenilworth, NJ 07033, USA
| | | | - Steve Previs
- MRL, 2000 Galloping Hill Road, Kenilworth, NJ 07033, USA
| | - Stuart Milstein
- Alnylam Pharmaceuticals, 300 Third Street, Cambridge, MA 02142, USA
| | - Kevin Fitzgerald
- Alnylam Pharmaceuticals, 300 Third Street, Cambridge, MA 02142, USA
| | - David E Kelley
- MRL, 2000 Galloping Hill Road, Kenilworth, NJ 07033, USA
| | - Jay D Horton
- Departments of Internal Medicine and Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046, USA.
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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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33
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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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Genomic structural variations for cardiovascular and metabolic comorbidity. Sci Rep 2017; 7:41268. [PMID: 28120895 PMCID: PMC5264603 DOI: 10.1038/srep41268] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 12/19/2016] [Indexed: 12/19/2022] Open
Abstract
The objective of this study was to identify genes targeted by both copy number and copy-neutral changes in the right coronary arteries in the area of advanced atherosclerotic plaques and intact internal mammary arteries derived from the same individuals with comorbid coronary artery disease and metabolic syndrome. The artery samples from 10 patients were screened for genomic imbalances using array comparative genomic hybridization. Ninety high-confidence, identical copy number variations (CNVs) were detected. We also identified eight copy-neutral changes (cn-LOHs) > 1.5 Mb in paired arterial samples in 4 of 10 individuals. The frequencies of the two gains located in the 10q24.31 (ERLIN1) and 12q24.11 (UNG, ACACB) genomic regions were evaluated in 33 paired arteries and blood samples. Two patients contained the gain in 10q24.31 (ERLIN1) and one patient contained the gain in 12q24.11 (UNG, ACACB) that affected only the blood DNA. An additional two patients harboured these CNVs in both the arteries and blood. In conclusion, we discovered and confirmed a gain of the 10q24.31 (ERLIN1) and 12q24.11 (UNG, ACACB) genomic regions in patients with coronary artery disease and metabolic comorbidity. Analysis of DNA extracted from blood indicated a possible somatic origin for these CNVs.
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A new leptin-mediated mechanism for stimulating fatty acid oxidation: a pivotal role for sarcolemmal FAT/CD36. Biochem J 2016; 474:149-162. [PMID: 27827305 DOI: 10.1042/bcj20160804] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2016] [Revised: 10/03/2016] [Accepted: 11/08/2016] [Indexed: 12/15/2022]
Abstract
Leptin stimulates fatty acid oxidation in muscle and heart; but, the mechanism by which these tissues provide additional intracellular fatty acids for their oxidation remains unknown. We examined, in isolated muscle and cardiac myocytes, whether leptin, via AMP-activated protein kinase (AMPK) activation, stimulated fatty acid translocase (FAT/CD36)-mediated fatty acid uptake to enhance fatty acid oxidation. In both mouse skeletal muscle and rat cardiomyocytes, leptin increased fatty acid oxidation, an effect that was blocked when AMPK phosphorylation was inhibited by adenine 9-β-d-arabinofuranoside or Compound C. In wild-type mice, leptin induced the translocation of FAT/CD36 to the plasma membrane and increased fatty acid uptake into giant sarcolemmal vesicles and into cardiomyocytes. In muscles of FAT/CD36-KO mice, and in cardiomyocytes in which cell surface FAT/CD36 action was blocked by sulfo-N-succinimidyl oleate, the leptin-stimulated influx of fatty acids was inhibited; concomitantly, the normal leptin-stimulated increase in fatty acid oxidation was also prevented, despite the normal leptin-induced increase in AMPK phosphorylation. Conversely, in muscle of AMPK kinase-dead mice, leptin failed to induce the translocation of FAT/CD36, along with a failure to stimulate fatty acid uptake and oxidation. Similarly, when siRNA was used to reduce AMPK in HL-1 cardiomyocytes, leptin failed to induce the translocation of FAT/CD36. Our studies have revealed a novel mechanism of leptin-induced fatty acid oxidation in muscle tissue; namely, this process is dependent on the activation of AMPK to induce the translocation of FAT/CD36 to the plasma membrane, thereby stimulating fatty acid uptake. Without increasing this leptin-stimulated, FAT/CD36-dependent fatty acid uptake process, leptin-stimulated AMPK phosphorylation does not enhance fatty acid oxidation.
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Cheng J, Zhang T, Ji H, Tao K, Guo J, Wei W. Functional characterization of AMP-activated protein kinase signaling in tumorigenesis. Biochim Biophys Acta Rev Cancer 2016; 1866:232-251. [PMID: 27681874 DOI: 10.1016/j.bbcan.2016.09.006] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Revised: 09/22/2016] [Accepted: 09/23/2016] [Indexed: 12/13/2022]
Abstract
AMP-activated protein kinase (AMPK) is a ubiquitously expressed metabolic sensor among various species. Specifically, cellular AMPK is phosphorylated and activated under certain stressful conditions, such as energy deprivation, in turn to activate diversified downstream substrates to modulate the adaptive changes and maintain metabolic homeostasis. Recently, emerging evidences have implicated the potential roles of AMPK signaling in tumor initiation and progression. Nevertheless, a comprehensive description on such topic is still in scarcity, especially in combination of its biochemical features with mouse modeling results to elucidate the physiological role of AMPK signaling in tumorigenesis. Hence, we performed this thorough review by summarizing the tumorigenic role of each component along the AMPK signaling, comprising of both its upstream and downstream effectors. Moreover, their functional interplay with the AMPK heterotrimer and exclusive efficacies in carcinogenesis were chiefly explained among genetically altered mice models. Importantly, the pharmaceutical investigations of AMPK relevant medications have also been highlighted. In summary, in this review, we not only elucidate the potential functions of AMPK signaling pathway in governing tumorigenesis, but also potentiate the future targeted strategy aiming for better treatment of aberrant metabolism-associated diseases, including cancer.
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Affiliation(s)
- Ji Cheng
- Department of Gastrointestinal Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, People's Republic of China; Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Tao Zhang
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Hongbin Ji
- Key Laboratory of Systems Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Science, Shanghai 200031, People's Republic of China
| | - Kaixiong Tao
- Department of Gastrointestinal Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, People's Republic of China.
| | - Jianping Guo
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA.
| | - Wenyi Wei
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA.
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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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Softic S, Cohen DE, Kahn CR. Role of Dietary Fructose and Hepatic De Novo Lipogenesis in Fatty Liver Disease. Dig Dis Sci 2016; 61:1282-93. [PMID: 26856717 PMCID: PMC4838515 DOI: 10.1007/s10620-016-4054-0] [Citation(s) in RCA: 409] [Impact Index Per Article: 51.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Accepted: 01/21/2016] [Indexed: 12/11/2022]
Abstract
Nonalcoholic fatty liver disease (NAFLD) is a liver manifestation of metabolic syndrome. Overconsumption of high-fat diet (HFD) and increased intake of sugar-sweetened beverages are major risk factors for development of NAFLD. Today the most commonly consumed sugar is high fructose corn syrup. Hepatic lipids may be derived from dietary intake, esterification of plasma free fatty acids (FFA) or hepatic de novo lipogenesis (DNL). A central abnormality in NAFLD is enhanced DNL. Hepatic DNL is increased in individuals with NAFLD, while the contribution of dietary fat and plasma FFA to hepatic lipids is not significantly altered. The importance of DNL in NAFLD is further established in mouse studies with knockout of genes involved in this process. Dietary fructose increases levels of enzymes involved in DNL even more strongly than HFD. Several properties of fructose metabolism make it particularly lipogenic. Fructose is absorbed via portal vein and delivered to the liver in much higher concentrations as compared to other tissues. Fructose increases protein levels of all DNL enzymes during its conversion into triglycerides. Additionally, fructose supports lipogenesis in the setting of insulin resistance as fructose does not require insulin for its metabolism, and it directly stimulates SREBP1c, a major transcriptional regulator of DNL. Fructose also leads to ATP depletion and suppression of mitochondrial fatty acid oxidation, resulting in increased production of reactive oxygen species. Furthermore, fructose promotes ER stress and uric acid formation, additional insulin independent pathways leading to DNL. In summary, fructose metabolism supports DNL more strongly than HFD and hepatic DNL is a central abnormality in NAFLD. Disrupting fructose metabolism in the liver may provide a new therapeutic option for the treatment of NAFLD.
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Affiliation(s)
- Samir Softic
- Section on Integrative Physiology and Metabolism, Joslin Diabetes Center, One Joslin Place, Boston, MA, 02215, USA
- Department of Gastroenterology, Hepatology and Nutrition, Boston Children's Hospital, Boston, MA, USA
| | - David E Cohen
- Division of Gastroenterology, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - C Ronald Kahn
- Section on Integrative Physiology and Metabolism, Joslin Diabetes Center, One Joslin Place, Boston, MA, 02215, USA.
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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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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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Gan L, Yan J, Liu Z, Feng M, Sun C. Adiponectin prevents reduction of lipid-induced mitochondrial biogenesis via AMPK/ACC2 pathway in chicken adipocyte. J Cell Biochem 2016; 116:1090-100. [PMID: 25536013 DOI: 10.1002/jcb.25064] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2014] [Accepted: 12/18/2014] [Indexed: 12/11/2022]
Abstract
Adiponectin (APN) stimulates mitochondrial biogenesis and reduces lipid content in human and animal adipocytes. However, the mechanism of adiponectin in regulating mitochondrial biogenesis in chicken adipocytes has never been reported. The objective of this study is to examine the mechanism that adiponectin plays in lipid-induced mitochondrial biogenesis and mitochondrial function in chicken adipocytes. We found that the overexpression of adiponectin reduced the membrane DAG content and elevated the membrane translocation of PKCθ. In contrast to control groups, the overexpression of adiponectin increased mitochondrial density and mitochondrial DNA contents and peroxisome proliferator-activated receptor αcoactivator 1α (PGC1-α) expression. Mitochondrial membrane potential and cytochrome C (Cyt C) content were detected by JC-1 fluorescent staining and immunofluorescence which indicated that overexpression of adiponectin enhanced mitochondrial ATP synthesis. Moreover, AMPK/ACC2 signaling pathway was activated along with the elevation of PGC1-α and TFAM by the overexpression of adiponectin, meanwhile the lipid transcription marker genes were down-regulated. This effect was alleviated by reducing adiponectin and a specific inhibitor of AMPK pathway. We concluded that adiponectin could prevent reduction of lipid-induced mitochondrial biogenesis via AMPK/ACC2 pathway in chicken adipocytes.
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Affiliation(s)
- Lu Gan
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, China
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Castro C, Freitag J, Berod L, Lochner M, Sparwasser T. Microbe-associated immunomodulatory metabolites: Influence on T cell fate and function. Mol Immunol 2015; 68:575-84. [DOI: 10.1016/j.molimm.2015.07.025] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Revised: 06/29/2015] [Accepted: 07/21/2015] [Indexed: 01/30/2023]
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Biotin-dependent functions in adiposity: a study of monozygotic twin pairs. Int J Obes (Lond) 2015; 40:788-95. [PMID: 26601567 DOI: 10.1038/ijo.2015.237] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Revised: 10/16/2015] [Accepted: 11/06/2015] [Indexed: 12/28/2022]
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Cordonier EL, Adjam R, Teixeira DC, Onur S, Zbasnik R, Read PE, Döring F, Schlegel VL, Zempleni J. Resveratrol compounds inhibit human holocarboxylase synthetase and cause a lean phenotype in Drosophila melanogaster. J Nutr Biochem 2015; 26:1379-84. [PMID: 26303405 DOI: 10.1016/j.jnutbio.2015.07.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Revised: 06/22/2015] [Accepted: 07/08/2015] [Indexed: 02/06/2023]
Abstract
Holocarboxylase synthetase (HLCS) is the sole protein-biotin ligase in the human proteome. HLCS has key regulatory functions in intermediary metabolism, including fatty acid metabolism, and in gene repression through epigenetic mechanisms. The objective of this study was to identify food-borne inhibitors of HLCS that alter HLCS-dependent pathways in metabolism and gene regulation. When libraries of extracts from natural products and chemically pure compounds were screened for HLCS inhibitor activity, resveratrol compounds in grape materials caused an HLCS inhibition of >98% in vitro. The potency of these compounds was piceatannol>resveratrol>piceid. Grape-borne compounds other than resveratrol metabolites also contributed toward HLCS inhibition, e.g., p-coumaric acid and cyanidin chloride. HLCS inhibitors had meaningful effects on body fat mass. When Drosophila melanogaster brummer mutants, which are genetically predisposed to storing excess amounts of lipids, were fed diets enriched with grape leaf extracts and piceid, body fat mass decreased by more than 30% in males and females. However, Drosophila responded to inhibitor treatment with an increase in the expression of HLCS, which elicited an increase in the abundance of biotinylated carboxylases in vivo. We conclude that mechanisms other than inhibition of HLCS cause body fat loss in flies. We propose that the primary candidate is the inhibition of the insulin receptor/Akt signaling pathway.
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Affiliation(s)
- Elizabeth L Cordonier
- Department of Nutrition and Health Sciences, University of Nebraska-Lincoln, 316 Ruth Leverton Hall, Lincoln, NE 68583-0806, USA
| | - Riem Adjam
- Department of Nutrition and Health Sciences, University of Nebraska-Lincoln, 316 Ruth Leverton Hall, Lincoln, NE 68583-0806, USA
| | - Daniel Camara Teixeira
- Department of Nutrition and Health Sciences, University of Nebraska-Lincoln, 316 Ruth Leverton Hall, Lincoln, NE 68583-0806, USA
| | - Simone Onur
- Abteilung Molekulare Prävention, Institut für Humanernährung und Lebensmittelkunde, Universität Kiel, Heinrich-Hecht-Platz 10, 24118 Kiel, Germany
| | - Richard Zbasnik
- Department of Food Science and Technology, University of Nebraska-Lincoln, 326 Filley Hall, Lincoln, NE 68583-0806, USA
| | - Paul E Read
- Department of Agronomy, University of Nebraska-Lincoln, 377 Plant Science Hall, Lincoln, NE 68583-0724, USA
| | - Frank Döring
- Abteilung Molekulare Prävention, Institut für Humanernährung und Lebensmittelkunde, Universität Kiel, Heinrich-Hecht-Platz 10, 24118 Kiel, Germany
| | - Vicki L Schlegel
- Department of Food Science and Technology, University of Nebraska-Lincoln, 326 Filley Hall, Lincoln, NE 68583-0806, USA
| | - Janos Zempleni
- Department of Nutrition and Health Sciences, University of Nebraska-Lincoln, 316 Ruth Leverton Hall, Lincoln, NE 68583-0806, USA.
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O'Neill HM, Lally JS, Galic S, Pulinilkunnil T, Ford RJ, Dyck JRB, van Denderen BJ, Kemp BE, Steinberg GR. Skeletal muscle ACC2 S212 phosphorylation is not required for the control of fatty acid oxidation during exercise. Physiol Rep 2015; 3:3/7/e12444. [PMID: 26156967 PMCID: PMC4552526 DOI: 10.14814/phy2.12444] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
During submaximal exercise fatty acids are a predominant energy source for muscle contractions. An important regulator of fatty acid oxidation is acetyl-CoA carboxylase (ACC), which exists as two isoforms (ACC1 and ACC2) with ACC2 predominating in skeletal muscle. Both ACC isoforms regulate malonyl-CoA production, an allosteric inhibitor of carnitine palmitoyltransferase 1 (CPT-1); the primary enzyme controlling fatty acyl-CoA flux into mitochondria for oxidation. AMP-activated protein kinase (AMPK) is a sensor of cellular energy status that is activated during exercise or by pharmacological agents such as metformin and AICAR. In resting muscle the activation of AMPK with AICAR leads to increased phosphorylation of ACC (S79 on ACC1 and S221 on ACC2), which reduces ACC activity and malonyl-CoA; effects associated with increased fatty acid oxidation. However, whether this pathway is vital for regulating skeletal muscle fatty acid oxidation during conditions of increased metabolic flux such as exercise/muscle contractions remains unknown. To examine this we characterized mice lacking AMPK phosphorylation sites on ACC2 (S212 in mice/S221 in humans-ACC2-knock-in [ACC2-KI]) or both ACC1 (S79) and ACC2 (S212) (ACC double knock-in [ACCD-KI]) during submaximal treadmill exercise and/or ex vivo muscle contractions. We find that surprisingly, ACC2-KI mice had normal exercise capacity and whole-body fatty acid oxidation during treadmill running despite elevated muscle ACC2 activity and malonyl-CoA. Similar results were observed in ACCD-KI mice. Fatty acid oxidation was also maintained in muscles from ACC2-KI mice contracted ex vivo. These findings indicate that pathways independent of ACC phosphorylation are important for regulating skeletal muscle fatty acid oxidation during exercise/muscle contractions.
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Affiliation(s)
- Hayley M O'Neill
- Division of Endocrinology and Metabolism, Department of Medicine, McMaster University, Hamilton, Ontario, Canada Department of Medicine, St. Vincent's Institute of Medical Research, University of Melbourne, Fitzroy, Victoria, Australia Faculty of Health Sciences and Medicine, Bond Institute of Health and Sport, Bond University, Robina, Queensland, Australia
| | - James S Lally
- Division of Endocrinology and Metabolism, Department of Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Sandra Galic
- Department of Medicine, St. Vincent's Institute of Medical Research, University of Melbourne, Fitzroy, Victoria, Australia
| | - Thomas Pulinilkunnil
- Department of Pediatrics, Faculty of Medicine and Dentistry, Cardiovascular Research Centre, Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Rebecca J Ford
- Division of Endocrinology and Metabolism, Department of Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Jason R B Dyck
- Department of Pediatrics, Faculty of Medicine and Dentistry, Cardiovascular Research Centre, Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Bryce J van Denderen
- Department of Medicine, St. Vincent's Institute of Medical Research, University of Melbourne, Fitzroy, Victoria, Australia
| | - Bruce E Kemp
- Department of Medicine, St. Vincent's Institute of Medical Research, University of Melbourne, Fitzroy, Victoria, Australia
| | - Gregory R Steinberg
- Division of Endocrinology and Metabolism, Department of Medicine, McMaster University, Hamilton, Ontario, Canada Department of Medicine, St. Vincent's Institute of Medical Research, University of Melbourne, Fitzroy, Victoria, Australia
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Valsangkar DS, Downs SM. Acetyl CoA carboxylase inactivation and meiotic maturation in mouse oocytes. Mol Reprod Dev 2015; 82:679-93. [PMID: 26043180 DOI: 10.1002/mrd.22505] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2014] [Accepted: 05/09/2015] [Indexed: 12/24/2022]
Abstract
In mouse oocytes, meiotic induction by pharmacological activation of PRKA (adenosine monophosphate-activated protein kinase; formerly known as AMPK) or by hormones depends on stimulation of fatty acid oxidation (FAO). PRKA stimulates FAO by phosphorylating and inactivating acetyl CoA carboxylase (ACAC; formerly ACC), leading to decreased malonyl CoA levels and augmenting fatty-acid transport into mitochondria. We investigated a role for ACAC inactivation in meiotic resumption by testing the effect of two ACAC inhibitors, CP-640186 and Soraphen A, on mouse oocytes maintained in meiotic arrest in vitro. These inhibitors significantly stimulated the resumption of meiosis in arrested cumulus cell-enclosed oocytes, denuded oocytes, and follicle-enclosed oocytes. This stimulation was accompanied by an increase in FAO. Etomoxir, a malonyl CoA analogue, prevented meiotic resumption as well as the increase in FAO induced by ACAC inhibition. Citrate, an ACAC activator, and CBM-301106, an inhibitor of malonyl CoA decarboxylase, which converts malonyl CoA to acetyl CoA, suppressed both meiotic induction and FAO induced by follicle-stimulating hormone, presumably by maintaining elevated malonyl CoA levels. Mouse oocyte-cumulus cell complexes contain both isoforms of ACAC (ACACA and ACACB); when wild-type and Acacb(-/-) oocytes characteristics were compared, we found that these single-knockout oocytes showed a significantly higher FAO level and a reduced ability to maintain meiotic arrest, resulting in higher rates of germinal vesicle breakdown. Collectively, these data support the model that ACAC inactivation contributes to the maturation-promoting activity of PRKA through stimulation of FAO.
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Affiliation(s)
- Deepa S Valsangkar
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin
| | - Stephen M Downs
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin
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Solinas G, Borén J, Dulloo AG. De novo lipogenesis in metabolic homeostasis: More friend than foe? Mol Metab 2015; 4:367-77. [PMID: 25973385 PMCID: PMC4421107 DOI: 10.1016/j.molmet.2015.03.004] [Citation(s) in RCA: 119] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Revised: 03/06/2015] [Accepted: 03/12/2015] [Indexed: 02/09/2023] Open
Abstract
Background An acute surplus of carbohydrates, and other substrates, can be converted and safely stored as lipids in adipocytes via de novo lipogenesis (DNL). However, in obesity, a condition characterized by chronic positive energy balance, DNL in non-adipose tissues may lead to ectopic lipid accumulation leading to lipotoxicity and metabolic stress. Indeed, DNL is dynamically recruited in liver during the development of fatty liver disease, where DNL is an important source of lipids. Nonetheless, a number of evidences indicates that DNL is an inefficient road for calorie to lipid conversion and that DNL may play an important role in sustaining metabolic homeostasis. Scope of review In this manuscript, we discuss the role of DNL as source of lipids during obesity, the energetic efficiency of this pathway in converting extra calories to lipids, and the function of DNL as a pathway supporting metabolic homeostasis. Major conclusion We conclude that inhibition of DNL in obese subjects, unless coupled with a correction of the chronic positive energy balance, may further promote lipotoxicity and metabolic stress. On the contrary, strategies aimed at specifically activating DNL in adipose tissue could support metabolic homeostasis in obese subjects by a number of mechanisms, which are discussed in this manuscript.
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Affiliation(s)
- Giovanni Solinas
- Department of Molecular and Clinical Medicine, Institute of Medicine, Sahlgrenska Academy, Wallenberg Laboratory, University of Gothenburg, Gothenburg, Sweden
| | - Jan Borén
- Department of Molecular and Clinical Medicine, Institute of Medicine, Sahlgrenska Academy, Wallenberg Laboratory, University of Gothenburg, Gothenburg, Sweden
| | - Abdul G Dulloo
- Division of Physiology, Department of Medicine, University of Fribourg, Fribourg, Switzerland
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Montgomery MK, Turner N. Mitochondrial dysfunction and insulin resistance: an update. Endocr Connect 2015; 4:R1-R15. [PMID: 25385852 PMCID: PMC4261703 DOI: 10.1530/ec-14-0092] [Citation(s) in RCA: 356] [Impact Index Per Article: 39.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Accepted: 11/10/2014] [Indexed: 12/11/2022]
Abstract
Mitochondrial dysfunction has been implicated in the development of insulin resistance (IR); however, a large variety of association and intervention studies as well as genetic manipulations in rodents have reported contrasting results. Indeed, even 39 years after the first publication describing a relationship between IR and diminished mitochondrial function, it is still unclear whether a direct relationship exists, and more importantly if changes in mitochondrial capacity are a cause or consequence of IR. This review will take a journey through the past and summarise the debate about the occurrence of mitochondrial dysfunction and its possible role in causing decreased insulin action in obesity and type 2 diabetes. Evidence is presented from studies in various human populations, as well as rodents with genetic manipulations of pathways known to affect mitochondrial function and insulin action. Finally, we have discussed whether mitochondria are a potential target for the treatment of IR.
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Affiliation(s)
- Magdalene K Montgomery
- Department of PharmacologyUNSW Medicine, School of Medical Sciences, University of New South Wales, Kensington, Sydney, New South Wales 2052, Australia
| | - Nigel Turner
- Department of PharmacologyUNSW Medicine, School of Medical Sciences, University of New South Wales, Kensington, Sydney, New South Wales 2052, Australia
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Cooper ME, Regnell SE. The hepatic cannabinoid 1 receptor as a modulator of hepatic energy state and food intake. Br J Clin Pharmacol 2015; 77:21-30. [PMID: 23452341 DOI: 10.1111/bcp.12102] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2012] [Accepted: 02/12/2013] [Indexed: 12/11/2022] Open
Abstract
The cannabinoid 1 receptor (CB1R) has a well-established role in appetite regulation. Central CB1R antagonists, notably rimonabant, induced weight loss and improved the metabolic profile in obese individuals, but were discontinued due to psychiatric side-effects. The CB1R is also expressed peripherally, where its effects include promotion of liver fat accumulation, which consumes ATP. Type 2 diabetes in obese subjects is linked to excess liver fat, whilst there is a negative correlation between hepatic ATP content and insulin resistance. A decreased hepatic ATP/AMP ratio increases food intake by signals via the vagus nerve to the brain. The hepatic cannabinoid system is highly upregulated in obesity, and the effects of hepatic CB1R activation include increased activity of lipogenic and gluconeogenic transcription factors. Thus, blockade of hepatic CB1Rs could contribute significantly to the weight-reducing and insulin-sensitizing effects of CB1R antagonists. Additionally, upregulation of the hepatic CB1R may contribute to chronic liver inflammation, fibrosis and cirrhosis from causes including obesity, alcoholism and viral hepatitis. Peripheral CB1R antagonists induce weight loss and metabolic improvements in obese rodents; however, as there is evidence that hepatic CB1Rs are predominately intracellular, due to high intrinsic clearance, many drugs may not effectively block these receptors and therefore have limited efficacy. Hepatoselective CB1R antagonists may be effective at reducing hepatic steatosis, insulin resistance and bodyweight in obese, diabetic patients, with far fewer side-effects than first-generation CB1R antagonists. Additionally, such compounds may be effective in treating inflammatory liver disease, such as non-alcoholic steatohepatitis, reducing the likelihood of disease progression to cirrhosis or cancer.
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