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Vieira-Lara MA, Bakker BM. The paradox of fatty-acid β-oxidation in muscle insulin resistance: Metabolic control and muscle heterogeneity. Biochim Biophys Acta Mol Basis Dis 2024; 1870:167172. [PMID: 38631409 DOI: 10.1016/j.bbadis.2024.167172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2023] [Revised: 03/18/2024] [Accepted: 04/09/2024] [Indexed: 04/19/2024]
Abstract
The skeletal muscle is a metabolically heterogeneous tissue that plays a key role in maintaining whole-body glucose homeostasis. It is well known that muscle insulin resistance (IR) precedes the development of type 2 diabetes. There is a consensus that the accumulation of specific lipid species in the tissue can drive IR. However, the role of the mitochondrial fatty-acid β-oxidation in IR and, consequently, in the control of glucose uptake remains paradoxical: interventions that either inhibit or activate fatty-acid β-oxidation have been shown to prevent IR. We here discuss the current theories and evidence for the interplay between β-oxidation and glucose uptake in IR. To address the underlying intricacies, we (1) dive into the control of glucose uptake fluxes into muscle tissues using the framework of Metabolic Control Analysis, and (2) disentangle concepts of flux and catalytic capacities taking into account skeletal muscle heterogeneity. Finally, we speculate about hitherto unexplored mechanisms that could bring contrasting evidence together. Elucidating how β-oxidation is connected to muscle IR and the underlying role of muscle heterogeneity enhances disease understanding and paves the way for new treatments for type 2 diabetes.
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Affiliation(s)
- Marcel A Vieira-Lara
- Laboratory of Pediatrics, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands.
| | - Barbara M Bakker
- Laboratory of Pediatrics, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands.
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2
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Stocks B, Zierath JR. Post-translational Modifications: The Signals at the Intersection of Exercise, Glucose Uptake, and Insulin Sensitivity. Endocr Rev 2022; 43:654-677. [PMID: 34730177 PMCID: PMC9277643 DOI: 10.1210/endrev/bnab038] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Indexed: 11/19/2022]
Abstract
Diabetes is a global epidemic, of which type 2 diabetes makes up the majority of cases. Nonetheless, for some individuals, type 2 diabetes is eminently preventable and treatable via lifestyle interventions. Glucose uptake into skeletal muscle increases during and in recovery from exercise, with exercise effective at controlling glucose homeostasis in individuals with type 2 diabetes. Furthermore, acute and chronic exercise sensitizes skeletal muscle to insulin. A complex network of signals converge and interact to regulate glucose metabolism and insulin sensitivity in response to exercise. Numerous forms of post-translational modifications (eg, phosphorylation, ubiquitination, acetylation, ribosylation, and more) are regulated by exercise. Here we review the current state of the art of the role of post-translational modifications in transducing exercise-induced signals to modulate glucose uptake and insulin sensitivity within skeletal muscle. Furthermore, we consider emerging evidence for noncanonical signaling in the control of glucose homeostasis and the potential for regulation by exercise. While exercise is clearly an effective intervention to reduce glycemia and improve insulin sensitivity, the insulin- and exercise-sensitive signaling networks orchestrating this biology are not fully clarified. Elucidation of the complex proteome-wide interactions between post-translational modifications and the associated functional implications will identify mechanisms by which exercise regulates glucose homeostasis and insulin sensitivity. In doing so, this knowledge should illuminate novel therapeutic targets to enhance insulin sensitivity for the clinical management of type 2 diabetes.
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Affiliation(s)
- Ben Stocks
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Juleen R Zierath
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark.,Departments of Molecular Medicine and Surgery and Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
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3
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White MF, Kahn CR. Insulin action at a molecular level - 100 years of progress. Mol Metab 2021; 52:101304. [PMID: 34274528 PMCID: PMC8551477 DOI: 10.1016/j.molmet.2021.101304] [Citation(s) in RCA: 94] [Impact Index Per Article: 31.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 07/07/2021] [Accepted: 07/13/2021] [Indexed: 12/15/2022] Open
Abstract
The discovery of insulin 100 years ago and its application to the treatment of human disease in the years since have marked a major turning point in the history of medicine. The availability of purified insulin allowed for the establishment of its physiological role in the regulation of blood glucose and ketones, the determination of its amino acid sequence, and the solving of its structure. Over the last 50 years, the function of insulin has been applied into the discovery of the insulin receptor and its signaling cascade to reveal the role of impaired insulin signaling-or resistance-in the progression of type 2 diabetes. It has also become clear that insulin signaling can impact not only classical insulin-sensitive tissues, but all tissues of the body, and that in many of these tissues the insulin signaling cascade regulates unexpected physiological functions. Despite these remarkable advances, much remains to be learned about both insulin signaling and how to use this molecular knowledge to advance the treatment of type 2 diabetes and other insulin-resistant states.
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Affiliation(s)
- Morris F White
- Boston Children's Hospital and Harvard Medical School, Boston, MA, 02215, USA.
| | - C Ronald Kahn
- Joslin Diabetes Center, Harvard Medical School, Boston, MA, 02215, USA.
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4
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Knudsen JR, Fritzen AM, James DE, Jensen TE, Kleinert M, Richter EA. Growth Factor-Dependent and -Independent Activation of mTORC2. Trends Endocrinol Metab 2020; 31:13-24. [PMID: 31699566 DOI: 10.1016/j.tem.2019.09.005] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 08/19/2019] [Accepted: 09/12/2019] [Indexed: 01/03/2023]
Abstract
The target of rapamycin complex 2 (TORC2) was discovered in 2002 in budding yeast. Its mammalian counterpart, mTORC2, was first described in 2004. Soon thereafter it was demonstrated that mTORC2 directly phosphorylates Akt on Ser473, ending a long search for the elusive 'second' insulin-responsive Akt kinase. In this review we discuss key evidence pertaining to the subcellular localization of mTORC2, highlighting a spatial heterogeneity that relates to mTORC2 activation. We summarize current models for how growth factors (GFs), such as insulin, trigger mTORC2 activation, and we provide a comprehensive discussion focusing on a new exciting frontier, the molecular mechanisms underpinning GF-independent activation of mTORC2.
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Affiliation(s)
- Jonas R Knudsen
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Andreas M Fritzen
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - David E James
- School of Life and Environmental Sciences and Charles Perkins Centre, The University of Sydney, Sydney, NSW, Australia; Sydney Medical School, The University of Sydney, Sydney, NSW, Australia
| | - Thomas E Jensen
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Maximilian Kleinert
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark; Institute for Diabetes and Obesity, Helmholtz Diabetes Center (HDC), Helmholtz Zentrum Muenchen & German Center for Diabetes Research (DZD), Neuherberg, Germany.
| | - Erik A Richter
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark.
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5
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Martins VF, Begur M, Lakkaraju S, Svensson K, Park J, Hetrick B, McCurdy CE, Schenk S. Acute inhibition of protein deacetylases does not impact skeletal muscle insulin action. Am J Physiol Cell Physiol 2019; 317:C964-C968. [PMID: 31461343 DOI: 10.1152/ajpcell.00159.2019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Whether the histone deacetylase (HDAC) and sirtuin families of protein deacetylases regulate insulin-stimulated glucose uptake, independent of their transcriptional effects, has not been studied. Our objective was to determine the nontranscriptional role of HDACs and sirtuins in regulation of skeletal muscle insulin action. Basal and insulin-stimulated glucose uptake and signaling and acetylation were assessed in L6 myotubes and skeletal muscle from C57BL/6J mice that were treated acutely (1 h) with HDAC (trichostatin A, panobinostat, TMP195) and sirtuin inhibitors (nicotinamide). Treatment of L6 myotubes with HDAC inhibitors or skeletal muscle with a combination of HDAC and sirtuin inhibitors increased tubulin and pan-protein acetylation, demonstrating effective impairment of HDAC and sirtuin deacetylase activities. Despite this, neither basal nor insulin-stimulated glucose uptake or insulin signaling was impacted. Acute reduction of the deacetylase activity of HDACs and/or sirtuins does not impact insulin action in skeletal muscle.
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Affiliation(s)
- Vitor F Martins
- Department of Orthopaedic Surgery, University of California San Diego, La Jolla, California.,Biomedical Sciences Graduate Program, University of California San Diego, La Jolla, California
| | - Maedha Begur
- Department of Orthopaedic Surgery, University of California San Diego, La Jolla, California
| | - Shivani Lakkaraju
- Department of Orthopaedic Surgery, University of California San Diego, La Jolla, California
| | - Kristoffer Svensson
- Department of Orthopaedic Surgery, University of California San Diego, La Jolla, California
| | - Ji Park
- Department of Orthopaedic Surgery, University of California San Diego, La Jolla, California
| | - Byron Hetrick
- Department of Human Physiology, University of Oregon, Eugene, Oregon
| | - Carrie E McCurdy
- Department of Human Physiology, University of Oregon, Eugene, Oregon
| | - Simon Schenk
- Department of Orthopaedic Surgery, University of California San Diego, La Jolla, California.,Biomedical Sciences Graduate Program, University of California San Diego, La Jolla, California
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Abstract
The cause of insulin resistance in obesity and type 2 diabetes mellitus (T2DM) is not limited to impaired insulin signalling but also involves the complex interplay of multiple metabolic pathways. The analysis of large data sets generated by metabolomics and lipidomics has shed new light on the roles of metabolites such as lipids, amino acids and bile acids in modulating insulin sensitivity. Metabolites can regulate insulin sensitivity directly by modulating components of the insulin signalling pathway, such as insulin receptor substrates (IRSs) and AKT, and indirectly by altering the flux of substrates through multiple metabolic pathways, including lipogenesis, lipid oxidation, protein synthesis and degradation and hepatic gluconeogenesis. Moreover, the post-translational modification of proteins by metabolites and lipids, including acetylation and palmitoylation, can alter protein function. Furthermore, the role of the microbiota in regulating substrate metabolism and insulin sensitivity is unfolding. In this Review, we discuss the emerging roles of metabolites in the pathogenesis of insulin resistance and T2DM. A comprehensive understanding of the metabolic adaptations involved in insulin resistance may enable the identification of novel targets for improving insulin sensitivity and preventing, and treating, T2DM.
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Martins VF, Dent JR, Svensson K, Tahvilian S, Begur M, Lakkaraju S, Buckner EH, LaBarge SA, Hetrick B, McCurdy CE, Schenk S. Germline or inducible knockout of p300 or CBP in skeletal muscle does not alter insulin sensitivity. Am J Physiol Endocrinol Metab 2019; 316:E1024-E1035. [PMID: 30888860 PMCID: PMC6620570 DOI: 10.1152/ajpendo.00497.2018] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Akt is a critical mediator of insulin-stimulated glucose uptake in skeletal muscle. The acetyltransferases, E1A binding protein p300 (p300) and cAMP response element-binding protein binding protein (CBP) are phosphorylated and activated by Akt, and p300/CBP can acetylate and inactivate Akt, thus giving rise to a possible Akt-p300/CBP axis. Our objective was to determine the importance of p300 and CBP to skeletal muscle insulin sensitivity. We used Cre-LoxP methodology to generate mice with germline [muscle creatine kinase promoter (P-MCK and C-MCK)] or inducible [tamoxifen-activated, human skeletal actin promoter (P-iHSA and C-iHSA)] knockout of p300 or CBP. A subset of P-MCK and C-MCK mice were switched to a calorie-restriction diet (60% of ad libitum intake) or high-fat diet at 10 wk of age. For P-iHSA and C-iHSA mice, knockout was induced at 10 wk of age. At 13-15 wk of age, we measured whole-body energy expenditure, oral glucose tolerance, and/or ex vivo skeletal muscle insulin sensitivity. Although p300 and CBP protein abundance and mRNA expression were reduced 55%-90% in p300 and CBP knockout mice, there were no genotype differences in energy expenditure or fasting glucose and insulin concentrations. Moreover, neither loss of p300 or CBP impacted oral glucose tolerance or skeletal muscle insulin sensitivity, nor did their loss impact alterations in these parameters in response to a calorie restriction or high-fat diet. Muscle-specific loss of either p300 or CBP, be it germline or in adulthood, does not impact energy expenditure, glucose tolerance, or skeletal muscle insulin action.
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Affiliation(s)
- Vitor F Martins
- Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, California
- Biomedical Sciences Graduate Program, University of California, San Diego, La Jolla, California
| | - Jessica R Dent
- Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, California
| | - Kristoffer Svensson
- Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, California
| | - Shahriar Tahvilian
- Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, California
| | - Maedha Begur
- Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, California
| | - Shivani Lakkaraju
- Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, California
| | - Elisa H Buckner
- Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, California
| | - Samuel A LaBarge
- Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, California
| | - Byron Hetrick
- Department of Human Physiology, University of Oregon , Eugene, Oregon
| | - Carrie E McCurdy
- Department of Human Physiology, University of Oregon , Eugene, Oregon
| | - Simon Schenk
- Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, California
- Biomedical Sciences Graduate Program, University of California, San Diego, La Jolla, California
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8
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Chung S, Hwang JT, Park JH, Choi HK. Free fatty acid-induced histone acetyltransferase activity accelerates lipid accumulation in HepG2 cells. Nutr Res Pract 2019; 13:196-204. [PMID: 31214287 PMCID: PMC6548710 DOI: 10.4162/nrp.2019.13.3.196] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Revised: 12/18/2018] [Accepted: 02/12/2019] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND/OBJECTIVES Non-alcoholic fatty liver disease (NAFLD) is a common metabolic disease triggered by epigenetic alterations, including lysine acetylation at histone or non-histone proteins, affecting the stability or transcription of lipogenic genes. Although various natural dietary compounds have anti-lipogenic effects, their effects on the acetylation status and lipid metabolism in the liver have not been thoroughly investigated. MATERIALS/METHODS Following oleic-palmitic acid (OPA)-induced lipid accumulation in HepG2 cells, the acetylation status of histone and non-histone proteins, HAT activity, and mRNA expression of representative lipogenic genes, including PPARγ, SREBP-1c, ACLY, and FASN, were evaluated. Furthermore, correlations between lipid accumulation and HAT activity for 22 representative natural food extracts (NExs) were evaluated. RESULTS Non-histone protein acetylation increased following OPA treatment and the acetylation of histones H3K9, H4K8, and H4K16 was accelerated, accompanied by an increase in HAT activity. OPA-induced increases in the mRNA expression of lipogenic genes were down-regulated by C-646, a p300/CBP-specific inhibitor. Finally, we detected a positive correlation between HAT activity and lipid accumulation (Pearson's correlation coefficient = 0.604) using 22 NExs. CONCLUSIONS Our results suggest that NExs have novel applications as nutraceutical agents with HAT inhibitor activity for the prevention and treatment of NAFLD.
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Affiliation(s)
- Sangwon Chung
- Korea Food Research Institute, 245, Nongsaengmyeong-ro, Iseo-myeon, Wanju-gun, Jeonbuk 55365, Republic of Korea
| | - Jin-Taek Hwang
- Korea Food Research Institute, 245, Nongsaengmyeong-ro, Iseo-myeon, Wanju-gun, Jeonbuk 55365, Republic of Korea.,Department of Food Biotechnology, Korea University of Science & Technology, Daejeon 34113, Republic of Korea
| | - Jae Ho Park
- Korea Food Research Institute, 245, Nongsaengmyeong-ro, Iseo-myeon, Wanju-gun, Jeonbuk 55365, Republic of Korea
| | - Hyo-Kyoung Choi
- Korea Food Research Institute, 245, Nongsaengmyeong-ro, Iseo-myeon, Wanju-gun, Jeonbuk 55365, Republic of Korea
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9
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Lantier L, Williams AS, Hughey CC, Bracy DP, James FD, Ansari MA, Gius D, Wasserman DH. SIRT2 knockout exacerbates insulin resistance in high fat-fed mice. PLoS One 2018; 13:e0208634. [PMID: 30533032 PMCID: PMC6289500 DOI: 10.1371/journal.pone.0208634] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 11/20/2018] [Indexed: 01/26/2023] Open
Abstract
The NAD+-dependent deacetylase SIRT2 is unique amongst sirtuins as it is effective in the cytosol, as well as the mitochondria. Defining the role of cytosolic acetylation state in specific tissues is difficult since even physiological effects at the whole body level are unknown. We hypothesized that genetic SIRT2 knockout (KO) would lead to impaired insulin action, and that this impairment would be worsened in HF fed mice. Insulin sensitivity was tested using the hyperinsulinemic-euglycemic clamp in SIRT2 KO mice and WT littermates. SIRT2 KO mice exhibited reduced skeletal muscle insulin-induced glucose uptake compared to lean WT mice, and this impairment was exacerbated in HF SIRT2 KO mice. Liver insulin sensitivity was unaffected in lean SIRT2 KO mice. However, the insulin resistance that accompanies HF-feeding was worsened in SIRT2 KO mice. It was notable that the effects of SIRT2 KO were largely disassociated from cytosolic acetylation state, but were closely linked to acetylation state in the mitochondria. SIRT2 KO led to an increase in body weight that was due to increased food intake in HF fed mice. In summary, SIRT2 deletion in vivo reduces muscle insulin sensitivity and contributes to liver insulin resistance by a mechanism that is unrelated to cytosolic acetylation state. Mitochondrial acetylation state and changes in feeding behavior that result in increased body weight correspond to the deleterious effects of SIRT2 KO on insulin action.
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Affiliation(s)
- Louise Lantier
- Department of Molecular Physiology & Biophysics, Vanderbilt University School of Medicine, Nashville TN, United States of America
- Vanderbilt Mouse Metabolic Phenotyping Center, Nashville, TN, United States of America
| | - Ashley S. Williams
- Department of Molecular Physiology & Biophysics, Vanderbilt University School of Medicine, Nashville TN, United States of America
| | - Curtis C. Hughey
- Department of Molecular Physiology & Biophysics, Vanderbilt University School of Medicine, Nashville TN, United States of America
| | - Deanna P. Bracy
- Department of Molecular Physiology & Biophysics, Vanderbilt University School of Medicine, Nashville TN, United States of America
| | - Freyja D. James
- Department of Molecular Physiology & Biophysics, Vanderbilt University School of Medicine, Nashville TN, United States of America
| | - Muhammad A. Ansari
- Department of Molecular Physiology & Biophysics, Vanderbilt University School of Medicine, Nashville TN, United States of America
| | - David Gius
- Department of Radiation Oncology, Northwestern University Feinberg School of Medicine, Chicago, IL, United States of America
| | - David H. Wasserman
- Department of Molecular Physiology & Biophysics, Vanderbilt University School of Medicine, Nashville TN, United States of America
- Vanderbilt Mouse Metabolic Phenotyping Center, Nashville, TN, United States of America
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10
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Liemburg-Apers DC, Wagenaars JAL, Smeitink JAM, Willems PHGM, Koopman WJH. Acute stimulation of glucose influx upon mitoenergetic dysfunction requires LKB1, AMPK, Sirt2 and mTOR-RAPTOR. J Cell Sci 2016; 129:4411-4423. [PMID: 27793977 DOI: 10.1242/jcs.194480] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 10/24/2016] [Indexed: 12/20/2022] Open
Abstract
Mitochondria play a central role in cellular energy production, and their dysfunction can trigger a compensatory increase in glycolytic flux to sustain cellular ATP levels. Here, we studied the mechanism of this homeostatic phenomenon in C2C12 myoblasts. Acute (30 min) mitoenergetic dysfunction induced by the mitochondrial inhibitors piericidin A and antimycin A stimulated Glut1-mediated glucose uptake without altering Glut1 (also known as SLC2A1) mRNA or plasma membrane levels. The serine/threonine liver kinase B1 (LKB1; also known as STK11) and AMP-activated protein kinase (AMPK) played a central role in this stimulation. In contrast, ataxia-telangiectasia mutated (ATM; a potential AMPK kinase) and hydroethidium (HEt)-oxidizing reactive oxygen species (ROS; increased in piericidin-A- and antimycin-A-treated cells) appeared not to be involved in the stimulation of glucose uptake. Treatment with mitochondrial inhibitors increased NAD+ and NADH levels (associated with a lower NAD+:NADH ratio) but did not affect the level of Glut1 acetylation. Stimulation of glucose uptake was greatly reduced by chemical inhibition of Sirt2 or mTOR-RAPTOR. We propose that mitochondrial dysfunction triggers LKB1-mediated AMPK activation, which stimulates Sirt2 phosphorylation, leading to activation of mTOR-RAPTOR and Glut1-mediated glucose uptake.
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Affiliation(s)
- Dania C Liemburg-Apers
- Department of Biochemistry (286), Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6500HB, Nijmegen, The Netherlands.,Centre for Systems Biology and Bioenergetics, Radboud University and Radboud University Medical Center, 6500HB, Nijmegen, The Netherlands.,Department of Pediatrics, Radboud Center for Mitochondrial Medicine, Radboud University Medical Center, 6525GA, Nijmegen, The Netherlands
| | - Jori A L Wagenaars
- Department of Biochemistry (286), Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6500HB, Nijmegen, The Netherlands.,Centre for Systems Biology and Bioenergetics, Radboud University and Radboud University Medical Center, 6500HB, Nijmegen, The Netherlands.,Department of Pediatrics, Radboud Center for Mitochondrial Medicine, Radboud University Medical Center, 6525GA, Nijmegen, The Netherlands
| | - Jan A M Smeitink
- Centre for Systems Biology and Bioenergetics, Radboud University and Radboud University Medical Center, 6500HB, Nijmegen, The Netherlands.,Department of Pediatrics, Radboud Center for Mitochondrial Medicine, Radboud University Medical Center, 6525GA, Nijmegen, The Netherlands
| | - Peter H G M Willems
- Department of Biochemistry (286), Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6500HB, Nijmegen, The Netherlands.,Centre for Systems Biology and Bioenergetics, Radboud University and Radboud University Medical Center, 6500HB, Nijmegen, The Netherlands.,Department of Pediatrics, Radboud Center for Mitochondrial Medicine, Radboud University Medical Center, 6525GA, Nijmegen, The Netherlands
| | - Werner J H Koopman
- Department of Biochemistry (286), Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6500HB, Nijmegen, The Netherlands .,Centre for Systems Biology and Bioenergetics, Radboud University and Radboud University Medical Center, 6500HB, Nijmegen, The Netherlands.,Department of Pediatrics, Radboud Center for Mitochondrial Medicine, Radboud University Medical Center, 6525GA, Nijmegen, The Netherlands
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11
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López-Rodríguez G, Osuna SK, García MG, Dieguez TS. Effects of dietary high fructose corn syrup on regulation of energy intake and leptin gene expression in rats. REV NUTR 2015. [DOI: 10.1590/1415-52732015000600003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVE: To evaluate in Wistar rats the effect of chronic use of high fructose corn syrup on serum lipids, body weight, energy intake regulation, and expression of associated genes. METHODS: For 11 weeks, male rats were fed a standard diet with either water (control) or 15% high fructose corn syrup solution, or fed a high-fat diet. The rats' food intake and body weight were measured weekly. Expression of leptin and fatty acid synthase genes was quantified in their brain and adipose tissue upon sacrifice at age 119 days using real-time polymerase chain reaction. RESULTS: The intake of 15% high fructose corn syrup did not affect the rats' weight, only the rats on the high-fat diet gained significant weight. The rats in both diets had lower levels of leptin expression and high levels of fatty acid synthase in the brain, which were associated with high serum triglycerides. CONCLUSION: Fifteen percent high fructose corn syrup intake and the high-fat diet reduced leptin gene expression in the brain of Wistar rats, with differential effects on weight gain.
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12
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Amaral MD, Balch WE. Hallmarks of therapeutic management of the cystic fibrosis functional landscape. J Cyst Fibros 2015; 14:687-99. [PMID: 26526359 PMCID: PMC4644672 DOI: 10.1016/j.jcf.2015.09.006] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Revised: 09/16/2015] [Accepted: 09/16/2015] [Indexed: 01/29/2023]
Abstract
The cystic fibrosis (CF) transmembrane conductance regulator (CFTR) protein does not operate in isolation, rather in a dynamic network of interacting components that impact its synthesis, folding, stability, intracellular location and function, referred to herein as the 'CFTR Functional Landscape (CFFL)'. For the prominent F508del mutation, many of these interactors are deeply connected to a protein fold management system, the proteostasis network (PN). However, CF encompasses an additional 2000 CFTR variants distributed along its entire coding sequence (referred to as CFTR2), and each variant contributes a differential liability to PN management of CFTR and to a protein 'social network' (SN) that directs the probability of the (patho)physiologic events that impact ion transport in each cell, tissue and patient in health and disease. Recognition of the importance of the PN and SN in driving the unique patient CFFL leading to disease highlights the importance of precision medicine in therapeutic management of disease progression. We take the view herein that it is not CFTR, rather the PN/SN, and their impact on the CFFL, that are the key physiologic forces driving onset and clinical progression of CF. We posit that a deep understanding of each patients PN/SN gained by merging genomic, proteomic (mass spectrometry (MS)), and high-content microscopy (HCM) technologies in the context of novel network learning algorithms will lead to a paradigm shift in CF clinical management. This should allow for generation of new classes of patient specific PN/SN directed therapeutics for personalized management of the CFFL in the clinic.
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Affiliation(s)
- Margarida D Amaral
- University of Lisboa, Faculty of Sciences, BioISI - Biosystems & Integrative Sciences Institute, Lisboa, Portugal.
| | - William E Balch
- Department of Chemical Physiology, Department of Cell and Molecular Biology, The Skaggs Institute of Chemical Biology, The Scripps Research Institute, La Jolla, CA, USA.
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