51
|
Oleoylethanolamide treatment reduces neurobehavioral deficits and brain pathology in a mouse model of Gulf War Illness. Sci Rep 2018; 8:12921. [PMID: 30150699 PMCID: PMC6110778 DOI: 10.1038/s41598-018-31242-7] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Accepted: 08/15/2018] [Indexed: 12/12/2022] Open
Abstract
There are nearly 250,000 Gulf War (GW) veterans who suffer from Gulf War Illness (GWI), a multi-symptom condition that remains untreatable. The main objective was to determine if targeting peroxisomal function could be of therapeutic value in GWI. We performed a pilot study that showed accumulation of very long chain fatty acids (VLCFA), which are metabolized in peroxisomes, in plasma from veterans with GWI. We then examined if targeting peroxisomal β-oxidation with oleoylethanolamide (OEA) restores these lipids to the normal levels and mitigates neuroinflammation and neurobehavioral deficits in a well-established mouse model of GWI. In GWI mice, treatment with OEA corresponded with cognitive benefits and reduced fatigue and disinhibition-like behavior in GWI mice. Biochemical and molecular analysis of the brain tissue showed reduced astroglia and microglia staining, decreased levels of chemokines and cytokines, and decreased NFκB phosphorylation. Treatment with OEA reduced accumulation of peroxisome specific VLCFA in the brains of GWI mice. These studies further support the translational value of targeting peroxisomes. We expect that OEA may be a potential therapy for treating neurobehavioral symptoms and the underlying lipid dysfunction and neuroinflammation associated with GWI. Oleoylethanolamide is available as a dietary supplement, making it appealing for human translational studies.
Collapse
|
52
|
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.
Collapse
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
| |
Collapse
|
53
|
Puerarin attenuates palmitate-induced mitochondrial dysfunction, impaired mitophagy and inflammation in L6 myotubes. Life Sci 2018; 206:84-92. [DOI: 10.1016/j.lfs.2018.05.041] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Revised: 05/22/2018] [Accepted: 05/23/2018] [Indexed: 01/16/2023]
|
54
|
Lund MT, Larsen S, Hansen M, Courraud J, Floyd AK, Støckel M, Helge JW, Dela F. Mitochondrial respiratory capacity remains stable despite a comprehensive and sustained increase in insulin sensitivity in obese patients undergoing gastric bypass surgery. Acta Physiol (Oxf) 2018; 223:e13032. [PMID: 29330917 DOI: 10.1111/apha.13032] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2017] [Revised: 01/05/2018] [Accepted: 01/05/2018] [Indexed: 12/15/2022]
Abstract
AIM It has been proposed, but not yet demonstrated by convincing evidence in published articles, that insulin resistance and mitochondrial respiratory function are causally related physiological phenomena. Here, we tested the prediction that weight loss-induced increase in insulin sensitivity will correlate with a corresponding change in mitochondrial respiratory capacity over the same time period. METHODS Insulin sensitivity was evaluated using the hyperinsulinaemic-euglycaemic clamp technique, and skeletal muscle mitochondrial respiratory capacity was evaluated by high-resolution respirometry in 26 patients with obesity. Each experiment was performed ~2 months and 1-2 weeks before, and ~4 and ~19 months after Roux-en-Y gastric bypass (RYGB) surgery. RESULTS A substantial weight loss was observed in all patients, and insulin sensitivity increased in all patients over the 21-months time period of the study. In contrast, skeletal muscle mitochondrial respiratory capacity, intrinsic mitochondrial respiratory capacity and mitochondrial content remained unchanged over the same time period. CONCLUSION Among obese patients with and without type 2 diabetes undergoing RYGB surgery, intrinsic mitochondrial respiratory capacity in skeletal muscle is not correlated with insulin sensitivity before or after the surgical intervention. Mitochondrial respiratory function may not be germane to the pathophysiology and/or aetiology of obesity and/or type 2 diabetes.
Collapse
Affiliation(s)
- M. T. Lund
- Xlab; Center for Healthy Aging; Department of Biomedical Sciences; University of Copenhagen; Copenhagen Denmark
- Department of Surgery; Holbak Hospital; Holbak Denmark
| | - S. Larsen
- Xlab; Center for Healthy Aging; Department of Biomedical Sciences; University of Copenhagen; Copenhagen Denmark
| | - M. Hansen
- Xlab; Center for Healthy Aging; Department of Biomedical Sciences; University of Copenhagen; Copenhagen Denmark
| | - J. Courraud
- Xlab; Center for Healthy Aging; Department of Biomedical Sciences; University of Copenhagen; Copenhagen Denmark
- Danish Center for Newborn screening; Department of Congenital Disorders; Statens Serum Institut; Copenhagen Denmark
| | - A. K. Floyd
- Department of Surgery; Holbak Hospital; Holbak Denmark
| | - M. Støckel
- Department of Surgery; Herlev University Hospital; Herlev Denmark
| | - J. W. Helge
- Xlab; Center for Healthy Aging; Department of Biomedical Sciences; University of Copenhagen; Copenhagen Denmark
| | - F. Dela
- Xlab; Center for Healthy Aging; Department of Biomedical Sciences; University of Copenhagen; Copenhagen Denmark
- Department of Geriatrics; Bispebjerg University Hospital; Copenhagen Denmark
| |
Collapse
|
55
|
Miller VJ, Villamena FA, Volek JS. Nutritional Ketosis and Mitohormesis: Potential Implications for Mitochondrial Function and Human Health. J Nutr Metab 2018; 2018:5157645. [PMID: 29607218 PMCID: PMC5828461 DOI: 10.1155/2018/5157645] [Citation(s) in RCA: 113] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Accepted: 12/27/2017] [Indexed: 02/07/2023] Open
Abstract
Impaired mitochondrial function often results in excessive production of reactive oxygen species (ROS) and is involved in the etiology of many chronic diseases, including cardiovascular disease, diabetes, neurodegenerative disorders, and cancer. Moderate levels of mitochondrial ROS, however, can protect against chronic disease by inducing upregulation of mitochondrial capacity and endogenous antioxidant defense. This phenomenon, referred to as mitohormesis, is induced through increased reliance on mitochondrial respiration, which can occur through diet or exercise. Nutritional ketosis is a safe and physiological metabolic state induced through a ketogenic diet low in carbohydrate and moderate in protein. Such a diet increases reliance on mitochondrial respiration and may, therefore, induce mitohormesis. Furthermore, the ketone β-hydroxybutyrate (BHB), which is elevated during nutritional ketosis to levels no greater than those resulting from fasting, acts as a signaling molecule in addition to its traditionally known role as an energy substrate. BHB signaling induces adaptations similar to mitohormesis, thereby expanding the potential benefit of nutritional ketosis beyond carbohydrate restriction. This review describes the evidence supporting enhancement of mitochondrial function and endogenous antioxidant defense in response to nutritional ketosis, as well as the potential mechanisms leading to these adaptations.
Collapse
Affiliation(s)
- Vincent J. Miller
- Department of Human Sciences, College of Education and Human Ecology, The Ohio State University, Columbus, OH, USA
| | - Frederick A. Villamena
- Department of Biological Chemistry and Pharmacology, College of Medicine, The Ohio State University, Columbus, OH, USA
| | - Jeff S. Volek
- Department of Human Sciences, College of Education and Human Ecology, The Ohio State University, Columbus, OH, USA
| |
Collapse
|
56
|
Choi JW, Ohn JH, Jung HS, Park YJ, Jang HC, Chung SS, Park KS. Carnitine induces autophagy and restores high-fat diet-induced mitochondrial dysfunction. Metabolism 2018; 78:43-51. [PMID: 28966077 DOI: 10.1016/j.metabol.2017.09.005] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Revised: 09/12/2017] [Accepted: 09/23/2017] [Indexed: 12/19/2022]
Abstract
OBJECTIVE Autophagy is suppressed in skeletal muscle and the liver with insulin resistance induced by a high-fat diet. Autophagy is essential for maintaining mitochondrial function, and dysfunctional mitochondria are associated with insulin resistance. As carnitine treatment is well known to improve insulin resistance by promoting mitochondrial function, we investigated if carnitine affects autophagy in the skeletal muscle of a high-fat diet-induced rodent model of obesity. RESULTS After 6weeks on a high-fat diet (48kcal% fat), mice developed glucose intolerance, and the gastrocnemius muscle showed a decrease in insulin signaling and mitochondrial function, which was reversed after carnitine (100mg/kg/day) treatment by oral gavage for 2weeks. Swollen mitochondria with destroyed cristae were observed in the skeletal muscle of high-fat diet-fed mice but were not there after carnitine treatment. High-fat diet decreased LC3B-II, a marker of autophagosome formation, and increased sequestosome 1 (SQSTM1), expression of which was reversed after carnitine treatment. In C2C12 myotubes, prolonged treatment with palmitate suppressed autophagy, which was relieved by carnitine treatment. However, the induction of autophagy by carnitine in C2C12 myotubes was not observed after knock-down of peroxisome proliferator-activated receptor γ (PPARγ), which is known to regulate autophagy. CONCLUSION We conclude that the removal of dysfunctional mitochondria by induction of autophagy through PPARγ may be a novel mechanism by which carnitine improves insulin resistance and mitochondrial dysfunction in obesity.
Collapse
Affiliation(s)
- Jin Woo Choi
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul 03080, Republic of Korea; Department of Internal Medicine, Seoul National University College of Medicine, Seoul 03080, Republic of Korea
| | - Jung Hun Ohn
- Department of Internal Medicine, Seoul National University College of Medicine, Seoul 03080, Republic of Korea; Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam 13620, Republic of Korea
| | - Hye Seung Jung
- Department of Internal Medicine, Seoul National University College of Medicine, Seoul 03080, Republic of Korea
| | - Young Joo Park
- Department of Internal Medicine, Seoul National University College of Medicine, Seoul 03080, Republic of Korea
| | - Hak Chul Jang
- Department of Internal Medicine, Seoul National University College of Medicine, Seoul 03080, Republic of Korea; Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam 13620, Republic of Korea
| | - Sung Soo Chung
- Department of Internal Medicine, Seoul National University College of Medicine, Seoul 03080, Republic of Korea.
| | - Kyong Soo Park
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul 03080, Republic of Korea; Department of Internal Medicine, Seoul National University College of Medicine, Seoul 03080, Republic of Korea; Department of Molecular Medicine and Biopharmaceutical Sciences, Graduate School of Convergence Science and Technology, Seoul National University College of Medicine, Seoul 03080, Republic of Korea.
| |
Collapse
|
57
|
IGF-1 Attenuates Hypoxia-Induced Atrophy but Inhibits Myoglobin Expression in C2C12 Skeletal Muscle Myotubes. Int J Mol Sci 2017; 18:ijms18091889. [PMID: 28862673 PMCID: PMC5618538 DOI: 10.3390/ijms18091889] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Revised: 08/23/2017] [Accepted: 08/29/2017] [Indexed: 12/26/2022] Open
Abstract
Chronic hypoxia is associated with muscle wasting and decreased oxidative capacity. By contrast, training under hypoxia may enhance hypertrophy and increase oxidative capacity as well as oxygen transport to the mitochondria, by increasing myoglobin (Mb) expression. The latter may be a feasible strategy to prevent atrophy under hypoxia and enhance an eventual hypertrophic response to anabolic stimulation. Mb expression may be further enhanced by lipid supplementation. We investigated individual and combined effects of hypoxia, insulin-like growth factor (IGF)-1 and lipids, in mouse skeletal muscle C2C12 myotubes. Differentiated C2C12 myotubes were cultured for 24 h under 20%, 5% and 2% oxygen with or without IGF-1 and/or lipid treatment. In culture under 20% oxygen, IGF-1 induced 51% hypertrophy. Hypertrophy was only 32% under 5% and abrogated under 2% oxygen. This was not explained by changes in expression of genes involved in contractile protein synthesis or degradation, suggesting a reduced rate of translation rather than of transcription. Myoglobin mRNA expression increased by 75% under 5% O2 but decreased by 50% upon IGF-1 treatment under 20% O2, compared to control. Inhibition of mammalian target of rapamycin (mTOR) activation using rapamycin restored Mb mRNA expression to control levels. Lipid supplementation had no effect on Mb gene expression. Thus, IGF-1-induced anabolic signaling can be a strategy to improve muscle size under mild hypoxia, but lowers Mb gene expression.
Collapse
|
58
|
Vartanian V, Tumova J, Dobrzyn P, Dobrzyn A, Nakabeppu Y, Lloyd RS, Sampath H. 8-oxoguanine DNA glycosylase (OGG1) deficiency elicits coordinated changes in lipid and mitochondrial metabolism in muscle. PLoS One 2017; 12:e0181687. [PMID: 28727777 PMCID: PMC5519207 DOI: 10.1371/journal.pone.0181687] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Accepted: 07/04/2017] [Indexed: 12/04/2022] Open
Abstract
Oxidative stress resulting from endogenous and exogenous sources causes damage to cellular components, including genomic and mitochondrial DNA. Oxidative DNA damage is primarily repaired via the base excision repair pathway that is initiated by DNA glycosylases. 8-oxoguanine DNA glycosylase (OGG1) recognizes and cleaves oxidized and ring-fragmented purines, including 8-oxoguanine, the most commonly formed oxidative DNA lesion. Mice lacking the OGG1 gene product are prone to multiple features of the metabolic syndrome, including high-fat diet-induced obesity, hepatic steatosis, and insulin resistance. Here, we report that OGG1-deficient mice also display skeletal muscle pathologies, including increased muscle lipid deposition and alterations in genes regulating lipid uptake and mitochondrial fission in skeletal muscle. In addition, expression of genes of the TCA cycle and of carbohydrate and lipid metabolism are also significantly altered in muscle of OGG1-deficient mice. These tissue changes are accompanied by marked reductions in markers of muscle function in OGG1-deficient animals, including decreased grip strength and treadmill endurance. Collectively, these data indicate a role for skeletal muscle OGG1 in the maintenance of optimal tissue function.
Collapse
Affiliation(s)
- Vladimir Vartanian
- From the Oregon Institute of Occupational Health Sciences, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Jana Tumova
- Department of Nutritional Sciences, Rutgers University, New Brunswick, New Jersey, United States of America
| | - Pawel Dobrzyn
- Nencki Institute of Experimental Biology, Warsaw, Poland
| | | | - Yusaku Nakabeppu
- Division of Neurofunctional Genomics, Department of Immunobiology and Neuroscience, Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan
| | - R. Stephen Lloyd
- From the Oregon Institute of Occupational Health Sciences, Oregon Health & Science University, Portland, Oregon, United States of America
- Department of Physiology and Pharmacology, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Harini Sampath
- Department of Nutritional Sciences, Rutgers University, New Brunswick, New Jersey, United States of America
- Rutgers Center for Lipid Research and Center for Digestive Health, New Jersey Institute for Food, Nutrition, and Health, Rutgers University, New Brunswick, New Jersey, United States of America
| |
Collapse
|
59
|
Acevedo LM, Raya AI, Ríos R, Aguilera-Tejero E, Rivero JLL. Obesity-induced discrepancy between contractile and metabolic phenotypes in slow- and fast-twitch skeletal muscles of female obese Zucker rats. J Appl Physiol (1985) 2017; 123:249-259. [PMID: 28522764 DOI: 10.1152/japplphysiol.00282.2017] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Revised: 05/10/2017] [Accepted: 05/10/2017] [Indexed: 01/02/2023] Open
Abstract
A clear picture of skeletal muscle adaptations to obesity and related comorbidities remains elusive. This study describes fiber-type characteristics (size, proportions, and oxidative enzyme activity) in two typical hindlimb muscles with opposite structure and function in an animal model of genetic obesity. Lesser fiber diameter, fiber-type composition, and histochemical succinic dehydrogenase activity (an oxidative marker) of muscle fiber types were assessed in slow (soleus)- and fast (tibialis cranialis)-twitch muscles of obese Zucker rats and compared with age (16 wk)- and sex (females)-matched lean Zucker rats (n = 16/group). Muscle mass and lesser fiber diameter were lower in both muscle types of obese compared with lean animals even though body weights were increased in the obese cohort. A faster fiber-type phenotype also occurred in slow- and fast-twitch muscles of obese rats compared with lean rats. These adaptations were accompanied by a significant increment in histochemical succinic dehydrogenase activity of slow-twitch fibers in the soleus muscle and fast-twitch fiber types in the tibialis cranialis muscle. Obesity significantly increased plasma levels of proinflammatory cytokines but did not significantly affect protein levels of peroxisome proliferator-activated receptors PPARγ or PGC1α in either muscle. These data demonstrate that, in female Zucker rats, obesity induces a reduction of muscle mass in which skeletal muscles show a diminished fiber size and a faster and more oxidative phenotype. It was noteworthy that this discrepancy in muscle's contractile and metabolic features was of comparable nature and extent in muscles with different fiber-type composition and antagonist functions.NEW & NOTEWORTHY This study demonstrates a discrepancy between morphological (reduced muscle mass), contractile (shift toward a faster phenotype), and metabolic (increased mitochondrial oxidative enzyme activity) characteristics in skeletal muscles of female Zucker fatty rats. It is noteworthy that this inconsistency was comparable (in nature and extent) in muscles with different structure and function.
Collapse
Affiliation(s)
- Luz M Acevedo
- Laboratorio de Biopatología Muscular, Departamento de Anatomía y Anatomía Patológica Comparadas, Universidad de Córdoba, Córdoba, Spain.,Departamento de Ciencias Biomédicas, Universidad Central de Venezuela, Maracay, Venezuela
| | - Ana I Raya
- Departamento de Medicina y Cirugía Animal, Universidad de Córdoba, Córdoba, Spain.,Instituto Maimónides de Investigación Biomédica de Córdoba, Hospital Universitario Reina Sofia, Universidad de Córdoba, Córdoba, Spain; and
| | - Rafael Ríos
- Departamento de Medicina y Cirugía Animal, Universidad de Córdoba, Córdoba, Spain.,Instituto Maimónides de Investigación Biomédica de Córdoba, Hospital Universitario Reina Sofia, Universidad de Córdoba, Córdoba, Spain; and
| | - Escolástico Aguilera-Tejero
- Departamento de Medicina y Cirugía Animal, Universidad de Córdoba, Córdoba, Spain.,Instituto Maimónides de Investigación Biomédica de Córdoba, Hospital Universitario Reina Sofia, Universidad de Córdoba, Córdoba, Spain; and
| | - José-Luis L Rivero
- Laboratorio de Biopatología Muscular, Departamento de Anatomía y Anatomía Patológica Comparadas, Universidad de Córdoba, Córdoba, Spain;
| |
Collapse
|
60
|
Skeletal Muscle Nucleo-Mitochondrial Crosstalk in Obesity and Type 2 Diabetes. Int J Mol Sci 2017; 18:ijms18040831. [PMID: 28420087 PMCID: PMC5412415 DOI: 10.3390/ijms18040831] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 04/01/2017] [Accepted: 04/08/2017] [Indexed: 12/15/2022] Open
Abstract
Skeletal muscle mitochondrial dysfunction, evidenced by incomplete beta oxidation and accumulation of fatty acid intermediates in the form of long and medium chain acylcarnitines, may contribute to ectopic lipid deposition and insulin resistance during high fat diet (HFD)-induced obesity. The present review discusses the roles of anterograde and retrograde communication in nucleo-mitochondrial crosstalk that determines skeletal muscle mitochondrial adaptations, specifically alterations in mitochondrial number and function in relation to obesity and insulin resistance. Special emphasis is placed on the effects of high fat diet (HFD) feeding on expression of nuclear-encoded mitochondrial genes (NEMGs) nuclear receptor factor 1 (NRF-1) and 2 (NRF-2) and peroxisome proliferator receptor gamma coactivator 1 alpha (PGC-1α) in the onset and progression of insulin resistance during obesity and how HFD-induced alterations in NEMG expression affect skeletal muscle mitochondrial adaptations in relation to beta oxidation of fatty acids. Finally, the potential ability of acylcarnitines or fatty acid intermediates resulting from mitochondrial beta oxidation to act as retrograde signals in nucleo-mitochondrial crosstalk is reviewed and discussed.
Collapse
|
61
|
Dubois V, Eeckhoute J, Lefebvre P, Staels B. Distinct but complementary contributions of PPAR isotypes to energy homeostasis. J Clin Invest 2017; 127:1202-1214. [PMID: 28368286 DOI: 10.1172/jci88894] [Citation(s) in RCA: 236] [Impact Index Per Article: 33.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Peroxisome proliferator-activated receptors (PPARs) regulate energy metabolism and hence are therapeutic targets in metabolic diseases such as type 2 diabetes and non-alcoholic fatty liver disease. While they share anti-inflammatory activities, the PPAR isotypes distinguish themselves by differential actions on lipid and glucose homeostasis. In this Review we discuss the complementary and distinct metabolic effects of the PPAR isotypes together with the underlying cellular and molecular mechanisms, as well as the synthetic PPAR ligands that are used in the clinic or under development. We highlight the potential of new PPAR ligands with improved efficacy and safety profiles in the treatment of complex metabolic disorders.
Collapse
|
62
|
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.
Collapse
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
| |
Collapse
|
63
|
López-Lluch G. Mitochondrial activity and dynamics changes regarding metabolism in ageing and obesity. Mech Ageing Dev 2017; 162:108-121. [DOI: 10.1016/j.mad.2016.12.005] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Revised: 10/24/2016] [Accepted: 12/13/2016] [Indexed: 12/14/2022]
|
64
|
Mannerås-Holm L, Schönke M, Brozinick JT, Vetterli L, Bui HH, Sanders P, Nascimento EBM, Björnholm M, Chibalin AV, Zierath JR. Diacylglycerol kinase ε deficiency preserves glucose tolerance and modulates lipid metabolism in obese mice. J Lipid Res 2017; 58:907-915. [PMID: 28246337 DOI: 10.1194/jlr.m074443] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 02/13/2017] [Indexed: 12/19/2022] Open
Abstract
Diacylglycerol kinases (DGKs) catalyze the phosphorylation and conversion of diacylglycerol (DAG) into phosphatidic acid. DGK isozymes have unique primary structures, expression patterns, subcellular localizations, regulatory mechanisms, and DAG preferences. DGKε has a hydrophobic segment that promotes its attachment to membranes and shows substrate specificity for DAG with an arachidonoyl acyl chain in the sn-2 position of the substrate. We determined the role of DGKε in the regulation of energy and glucose homeostasis in relation to diet-induced insulin resistance and obesity using DGKε-KO and wild-type mice. Lipidomic analysis revealed elevated unsaturated and saturated DAG species in skeletal muscle of DGKε KO mice, which was paradoxically associated with increased glucose tolerance. Although skeletal muscle insulin sensitivity was unaltered, whole-body respiratory exchange ratio was reduced, and abundance of mitochondrial markers was increased, indicating a greater reliance on fat oxidation and intracellular lipid metabolism in DGKε KO mice. Thus, the increased intracellular lipids in skeletal muscle from DGKε KO mice may undergo rapid turnover because of increased mitochondrial function and lipid oxidation, rather than storage, which in turn may preserve insulin sensitivity. In conclusion, DGKε plays a role in glucose and energy homeostasis by modulating lipid metabolism in skeletal muscle.
Collapse
Affiliation(s)
- Louise Mannerås-Holm
- Section of Integrative Physiology, Department of Molecular Medicine and Surgery and Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Milena Schönke
- Section of Integrative Physiology, Department of Molecular Medicine and Surgery and Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | | | - Laurène Vetterli
- Section of Integrative Physiology, Department of Molecular Medicine and Surgery and Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Hai-Hoang Bui
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN
| | - Philip Sanders
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN
| | - Emmani B M Nascimento
- Section of Integrative Physiology, Department of Molecular Medicine and Surgery and Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Marie Björnholm
- Section of Integrative Physiology, Department of Molecular Medicine and Surgery and Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Alexander V Chibalin
- Section of Integrative Physiology, Department of Molecular Medicine and Surgery and Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Juleen R Zierath
- Section of Integrative Physiology, Department of Molecular Medicine and Surgery and Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| |
Collapse
|
65
|
Brøns C, Grunnet LG. MECHANISMS IN ENDOCRINOLOGY: Skeletal muscle lipotoxicity in insulin resistance and type 2 diabetes: a causal mechanism or an innocent bystander? Eur J Endocrinol 2017; 176:R67-R78. [PMID: 27913612 DOI: 10.1530/eje-16-0488] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Revised: 08/19/2016] [Accepted: 09/14/2016] [Indexed: 12/11/2022]
Abstract
Dysfunctional adipose tissue is associated with an increased risk of developing type 2 diabetes (T2D). One characteristic of a dysfunctional adipose tissue is the reduced expandability of the subcutaneous adipose tissue leading to ectopic storage of fat in organs and/or tissues involved in the pathogenesis of T2D that can cause lipotoxicity. Accumulation of lipids in the skeletal muscle is associated with insulin resistance, but the majority of previous studies do not prove any causality. Most studies agree that it is not the intramuscular lipids per se that causes insulin resistance, but rather lipid intermediates such as diacylglycerols, fatty acyl-CoAs and ceramides and that it is the localization, composition and turnover of these intermediates that play an important role in the development of insulin resistance and T2D. Adipose tissue is a more active tissue than previously thought, and future research should thus aim at examining the exact role of lipid composition, cellular localization and the dynamics of lipid turnover on the development of insulin resistance. In addition, ectopic storage of fat has differential impact on various organs in different phenotypes at risk of developing T2D; thus, understanding how adipogenesis is regulated, the interference with metabolic outcomes and what determines the capacity of adipose tissue expandability in distinct population groups is necessary. This study is a review of the current literature on the adipose tissue expandability hypothesis and how the following ectopic lipid accumulation as a consequence of a limited adipose tissue expandability may be associated with insulin resistance in muscle and liver.
Collapse
Affiliation(s)
- Charlotte Brøns
- Department of Endocrinology (Diabetes and Metabolism)Rigshospitalet, Copenhagen, Denmark
| | - Louise Groth Grunnet
- Department of Endocrinology (Diabetes and Metabolism)Rigshospitalet, Copenhagen, Denmark
| |
Collapse
|
66
|
Gonzalez-Franquesa A, Patti ME. Insulin Resistance and Mitochondrial Dysfunction. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 982:465-520. [DOI: 10.1007/978-3-319-55330-6_25] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
|
67
|
Han D, Johnson HS, Rao MP, Martin G, Sancheti H, Silkwood KH, Decker CW, Nguyen KT, Casian JG, Cadenas E, Kaplowitz N. Mitochondrial remodeling in the liver following chronic alcohol feeding to rats. Free Radic Biol Med 2017; 102:100-110. [PMID: 27867097 PMCID: PMC5209270 DOI: 10.1016/j.freeradbiomed.2016.11.020] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Revised: 09/13/2016] [Accepted: 11/10/2016] [Indexed: 02/07/2023]
Abstract
The feeding of alcohol orally (Lieber-DeCarli diet) to rats has been shown to cause declines in mitochondrial respiration (state III), decreased expression of respiratory complexes, and decreased respiratory control ratios (RCR) in liver mitochondria. These declines and other mitochondrial alterations have led to the hypothesis that alcohol feeding causes "mitochondrial dysfunction" in the liver. If oral alcohol feeding leads to mitochondrial dysfunction, one would predict that increasing alcohol delivery by intragastric (IG) alcohol feeding to rats would cause greater declines in mitochondrial bioenergetics in the liver. In this study, we examined the mitochondrial alterations that occur in rats fed alcohol both orally and intragastrically. Oral alcohol feeding decreased glutamate/malate-, acetaldehyde- and succinate-driven state III respiration, RCR, and expression of respiratory complexes (I, III, IV, V) in liver mitochondria, in agreement with previous results. IG alcohol feeding, on the other hand, caused a slight increase in glutamate/malate-driven respiration, and significantly increased acetaldehyde-driven respiration in liver mitochondria. IG feeding also caused liver mitochondria to experience a decline in succinate-driven respiration, but these decreases were smaller than those observed with oral alcohol feeding. Surprisingly, oral and IG alcohol feeding to rats increased mitochondrial respiration using other substrates, including glycerol-3-phosphate (which delivers electrons from cytoplasmic NADH to mitochondria) and octanoate (a substrate for beta-oxidation). The enhancement of glycerol-3-phosphate- and octanoate-driven respiration suggests that liver mitochondria remodeled in response to alcohol feeding. In support of this notion, we observed that IG alcohol feeding also increased expression of mitochondrial glycerol phosphate dehydrogenase-2 (GPD2), transcription factor A (TFAM), and increased mitochondrial NAD+-NADH and NADP+-NADPH levels in the liver. Our findings suggest that mitochondrial dysfunction represents an incomplete picture of mitochondrial dynamics that occur in the liver following alcohol feeding. While alcohol feeding causes some mitochondrial dysfunction (i.e. succinate-driven respiration), our work suggests that the major consequence of alcohol feeding is mitochondrial remodeling in the liver as an adaptation. This mitochondrial remodeling may play an important role in the enhanced alcohol metabolism and other adaptations in the liver that develop with alcohol intake.
Collapse
Affiliation(s)
- Derick Han
- Department of Biopharmaceutical Sciences, School of Pharmacy, Keck Graduate Institute, 535 Watson Drive, Claremont, CA 91711, USA.
| | - Heather S Johnson
- University of Southern California Research Center for Liver Diseases and Southern California Research Center for ALPD, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089-9121, USA
| | - Madhuri P Rao
- W.M. Keck Science Department, Scripps College, Claremont, CA 91711, USA
| | - Gary Martin
- Department of Biology, Occidental College, Los Angeles, CA 90041, USA
| | - Harsh Sancheti
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA 90089, USA
| | - Kai H Silkwood
- Department of Chemistry and Biochemistry, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0303, USA
| | - Carl W Decker
- Department of Biopharmaceutical Sciences, School of Pharmacy, Keck Graduate Institute, 535 Watson Drive, Claremont, CA 91711, USA
| | - Kim Tho Nguyen
- Department of Biopharmaceutical Sciences, School of Pharmacy, Keck Graduate Institute, 535 Watson Drive, Claremont, CA 91711, USA
| | - Joseph G Casian
- Department of Biopharmaceutical Sciences, School of Pharmacy, Keck Graduate Institute, 535 Watson Drive, Claremont, CA 91711, USA
| | - Enrique Cadenas
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA 90089, USA
| | - Neil Kaplowitz
- University of Southern California Research Center for Liver Diseases and Southern California Research Center for ALPD, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089-9121, USA
| |
Collapse
|
68
|
McCurdy CE, Schenk S, Hetrick B, Houck J, Drew BG, Kaye S, Lashbrook M, Bergman BC, Takahashi DL, Dean TA, Nemkov T, Gertsman I, Hansen KC, Philp A, Hevener AL, Chicco AJ, Aagaard KM, Grove KL, Friedman JE. Maternal obesity reduces oxidative capacity in fetal skeletal muscle of Japanese macaques. JCI Insight 2016; 1:e86612. [PMID: 27734025 DOI: 10.1172/jci.insight.86612] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Maternal obesity is proposed to alter the programming of metabolic systems in the offspring, increasing the risk for developing metabolic diseases; however, the cellular mechanisms remain poorly understood. Here, we used a nonhuman primate model to examine the impact of a maternal Western-style diet (WSD) alone, or in combination with obesity (Ob/WSD), on fetal skeletal muscle metabolism studied in the early third trimester. We find that fetal muscle responds to Ob/WSD by upregulating fatty acid metabolism, mitochondrial complex activity, and metabolic switches (CPT-1, PDK4) that promote lipid utilization over glucose oxidation. Ob/WSD fetuses also had reduced mitochondrial content, diminished oxidative capacity, and lower mitochondrial efficiency in muscle. The decrease in oxidative capacity and glucose metabolism was persistent in primary myotubes from Ob/WSD fetuses despite no additional lipid-induced stress. Switching obese mothers to a healthy diet prior to pregnancy did not improve fetal muscle mitochondrial function. Lastly, while maternal WSD alone led only to intermediary changes in fetal muscle metabolism, it was sufficient to increase oxidative damage and cellular stress. Our findings suggest that maternal obesity or WSD, alone or in combination, leads to programmed decreases in oxidative metabolism in offspring muscle. These alterations may have important implications for future health.
Collapse
Affiliation(s)
- Carrie E McCurdy
- Department of Human Physiology, University of Oregon, Eugene, Oregon, USA.,Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Simon Schenk
- Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, California, USA
| | - Byron Hetrick
- Department of Human Physiology, University of Oregon, Eugene, Oregon, USA
| | - Julie Houck
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Brian G Drew
- David Geffen School of Medicine, Department of Medicine, Division of Endocrinology, Diabetes and Hypertension, University of California, Los Angeles, Los Angeles, California, USA.,Diabetes and Dyslipidaemia Laboratory, Baker IDI Heart and Diabetes Institute, Prahran, Victoria, Australia
| | - Spencer Kaye
- Departments of Health and Exercise Science and Biomedical Sciences, Colorado State University, Fort Collins, Colorado, USA
| | - Melanie Lashbrook
- Departments of Health and Exercise Science and Biomedical Sciences, Colorado State University, Fort Collins, Colorado, USA
| | - Bryan C Bergman
- Division of Endocrinology, Metabolism, and Diabetes, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Diana L Takahashi
- Division of Diabetes, Obesity and Metabolism, Oregon National Primate Research Center, Beaverton, Oregon, USA
| | - Tyler A Dean
- Division of Diabetes, Obesity and Metabolism, Oregon National Primate Research Center, Beaverton, Oregon, USA
| | - Travis Nemkov
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Ilya Gertsman
- Department of Pediatrics, University of California, San Diego, La Jolla, California, USA
| | - Kirk C Hansen
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Andrew Philp
- School of Sport Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, B15 2TT, United Kingdom
| | - Andrea L Hevener
- David Geffen School of Medicine, Department of Medicine, Division of Endocrinology, Diabetes and Hypertension, University of California, Los Angeles, Los Angeles, California, USA
| | - Adam J Chicco
- Departments of Health and Exercise Science and Biomedical Sciences, Colorado State University, Fort Collins, Colorado, USA
| | - Kjersti M Aagaard
- Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Baylor College of Medicine and Texas Children's Hospital, Houston, Texas, USA
| | - Kevin L Grove
- Division of Diabetes, Obesity and Metabolism, Oregon National Primate Research Center, Beaverton, Oregon, USA.,Novo Nordisk Research Center, Seattle, Washington, USA
| | - Jacob E Friedman
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| |
Collapse
|
69
|
Affourtit C. Mitochondrial involvement in skeletal muscle insulin resistance: A case of imbalanced bioenergetics. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2016; 1857:1678-93. [PMID: 27473535 DOI: 10.1016/j.bbabio.2016.07.008] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Revised: 06/19/2016] [Accepted: 07/23/2016] [Indexed: 12/16/2022]
Abstract
Skeletal muscle insulin resistance in obesity associates with mitochondrial dysfunction, but the causality of this association is controversial. This review evaluates mitochondrial models of nutrient-induced muscle insulin resistance. It transpires that all models predict that insulin resistance arises as a result of imbalanced cellular bioenergetics. The nature and precise origin of the proposed insulin-numbing molecules differ between models but all species only accumulate when metabolic fuel supply outweighs energy demand. This observation suggests that mitochondrial deficiency in muscle insulin resistance is not merely owing to intrinsic functional defects, but could instead be an adaptation to nutrient-induced changes in energy expenditure. Such adaptive effects are likely because muscle ATP supply is fully driven by energy demand. This market-economic control of myocellular bioenergetics offers a mechanism by which insulin-signalling deficiency can cause apparent mitochondrial dysfunction, as insulin resistance lowers skeletal muscle anabolism and thus dampens ATP demand and, consequently, oxidative ATP synthesis.
Collapse
Affiliation(s)
- Charles Affourtit
- School of Biomedical and Healthcare Sciences, Plymouth University Peninsula Schools of Medicine and Dentistry, Plymouth University, Drake Circus, PL4 8AA Plymouth, UK.
| |
Collapse
|
70
|
Hill CM, Fang Y, Miquet JG, Sun LY, Masternak MM, Bartke A. Long-lived hypopituitary Ames dwarf mice are resistant to the detrimental effects of high-fat diet on metabolic function and energy expenditure. Aging Cell 2016; 15:509-21. [PMID: 26990883 PMCID: PMC4854906 DOI: 10.1111/acel.12467] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/29/2016] [Indexed: 12/11/2022] Open
Abstract
Growth hormone (GH) signaling stimulates the production of IGF‐1; however, increased GH signaling may induce insulin resistance and can reduce life expectancy in both mice and humans. Interestingly, disruption of GH signaling by reducing plasma GH levels significantly improves health span and extends lifespan in mice, as observed in Ames dwarf mice. In addition, these mice have increased adiposity, yet are more insulin sensitive compared to control mice. Metabolic stressors such as high‐fat diet (HFD) promote obesity and may alter longevity through the GH signaling pathway. Therefore, our objective was to investigate the effects of a HFD (metabolic stressor) on genetic mechanisms that regulate metabolism during aging. We show that Ames dwarf mice fed HFD for 12 weeks had an increase in subcutaneous and visceral adiposity as a result of diet‐induced obesity, yet are more insulin sensitive and have higher levels of adiponectin compared to control mice fed HFD. Furthermore, energy expenditure was higher in Ames dwarf mice fed HFD than in control mice fed HFD. Additionally, we show that transplant of epididymal white adipose tissue (eWAT) from Ames dwarf mice fed HFD into control mice fed HFD improves their insulin sensitivity. We conclude that Ames dwarf mice are resistant to the detrimental metabolic effects of HFD and that visceral adipose tissue of Ames dwarf mice improves insulin sensitivity in control mice fed HFD.
Collapse
Affiliation(s)
- Cristal M. Hill
- Department of Medical Microbiology, Immunology and Cell Biology Southern Illinois University School of Medicine Springfield IL USA
- Department of Internal Medicine, Geriatrics Research Southern Illinois University School of Medicine Springfield IL USA
| | - Yimin Fang
- Department of Internal Medicine, Geriatrics Research Southern Illinois University School of Medicine Springfield IL USA
| | - Johanna G. Miquet
- Faculty of Pharmacy and Biochemistry Institute of Chemical and Biological Physical Chemistry Buenos Aires Argentina
| | - Liou Y. Sun
- Department of Biology University of Alabama at Birmingham Birmingham AL USA
| | - Michal M. Masternak
- Burnett School of Biomedical Sciences‐ College of Medicine University of Central Florida Orlando FL USA
| | - Andrzej Bartke
- Department of Medical Microbiology, Immunology and Cell Biology Southern Illinois University School of Medicine Springfield IL USA
- Department of Internal Medicine, Geriatrics Research Southern Illinois University School of Medicine Springfield IL USA
| |
Collapse
|
71
|
Alternate-Day High-Fat Diet Induces an Increase in Mitochondrial Enzyme Activities and Protein Content in Rat Skeletal Muscle. Nutrients 2016; 8:203. [PMID: 27058555 PMCID: PMC4848672 DOI: 10.3390/nu8040203] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Revised: 03/25/2016] [Accepted: 03/30/2016] [Indexed: 11/20/2022] Open
Abstract
Long-term high-fat diet increases muscle mitochondrial enzyme activity and endurance performance. However, excessive calorie intake causes intra-abdominal fat accumulation and metabolic syndrome. The purpose of this study was to investigate the effect of an alternating day high-fat diet on muscle mitochondrial enzyme activities, protein content, and intra-abdominal fat mass in rats. Male Wistar rats were given a standard chow diet (CON), high-fat diet (HFD), or alternate-day high-fat diet (ALT) for 4 weeks. Rats in the ALT group were fed a high-fat diet and standard chow every other day for 4 weeks. After the dietary intervention, mitochondrial enzyme activities and protein content in skeletal muscle were measured. Although body weight did not differ among groups, the epididymal fat mass in the HFD group was higher than those of the CON and ALT groups. Citrate synthase and beta-hydroxyacyl CoA dehydrogenase activities in the plantaris muscle of rats in HFD and ALT were significantly higher than that in CON rats, whereas there was no difference between HFD and ALT groups. No significant difference was observed in muscle glycogen concentration or glucose transporter-4 protein content among the three groups. These results suggest that an alternate-day high-fat diet induces increases in mitochondrial enzyme activities and protein content in rat skeletal muscle without intra-abdominal fat accumulation.
Collapse
|
72
|
Kakehi S, Tamura Y, Takeno K, Sakurai Y, Kawaguchi M, Watanabe T, Funayama T, Sato F, Ikeda SI, Kanazawa A, Fujitani Y, Kawamori R, Watada H. Increased intramyocellular lipid/impaired insulin sensitivity is associated with altered lipid metabolic genes in muscle of high responders to a high-fat diet. Am J Physiol Endocrinol Metab 2016; 310:E32-40. [PMID: 26487001 DOI: 10.1152/ajpendo.00220.2015] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Accepted: 10/16/2015] [Indexed: 01/07/2023]
Abstract
The accumulation of intramyocellular lipid (IMCL) is recognized as an important determinant of insulin resistance, and is increased by a high-fat diet (HFD). However, the effects of HFD on IMCL and insulin sensitivity are highly variable. The aim of this study was to identify the genes in muscle that are related to this inter-individual variation. Fifty healthy men were recruited for this study. Before and after HFD for 3 days, IMCL levels in the tibialis anterior were measured by (1)H magnetic resonance spectroscopy, and peripheral insulin sensitivity was evaluated by glucose infusion rate (GIR) during the euglycemic-hyperinsulinemic clamp. Subjects who showed a large increase in IMCL and a large decrease in GIR by HFD were classified as high responders (HRs), and subjects who showed a small increase in IMCL and a small decrease in GIR were classified as low responders (LRs). In five subjects from each group, the gene expression profile of the vastus lateralis muscle was analyzed by DNA microarray analysis. Before HFD, gene expression profiles related to lipid metabolism were comparable between the two groups. Gene Set Enrichment Analysis demonstrated that five gene sets related to lipid metabolism were upregulated by HFD in the HR group but not in the LR group. Changes in gene expression patterns were confirmed by qRT-PCR using more samples (LR, n = 9; HR, n = 11). These results suggest that IMCL accumulation/impaired insulin sensitivity after HFD is closely associated with changes in the expression of genes related to lipid metabolism in muscle.
Collapse
Affiliation(s)
- Saori Kakehi
- Department of Metabolism and Endocrinology, Juntendo University Graduate School of Medicine, Tokyo, Japan; Sportology Center, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Yoshifumi Tamura
- Department of Metabolism and Endocrinology, Juntendo University Graduate School of Medicine, Tokyo, Japan; Sportology Center, Juntendo University Graduate School of Medicine, Tokyo, Japan;
| | - Kageumi Takeno
- Department of Metabolism and Endocrinology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Yuko Sakurai
- Department of Metabolism and Endocrinology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Minako Kawaguchi
- Department of Metabolism and Endocrinology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Takahiro Watanabe
- Department of Metabolism and Endocrinology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Takashi Funayama
- Department of Metabolism and Endocrinology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Fumihiko Sato
- Department of Metabolism and Endocrinology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Shin-Ichi Ikeda
- Department of Metabolism and Endocrinology, Juntendo University Graduate School of Medicine, Tokyo, Japan; Sportology Center, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Akio Kanazawa
- Department of Metabolism and Endocrinology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Yoshio Fujitani
- Department of Metabolism and Endocrinology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Ryuzo Kawamori
- Department of Metabolism and Endocrinology, Juntendo University Graduate School of Medicine, Tokyo, Japan; Sportology Center, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Hirotaka Watada
- Department of Metabolism and Endocrinology, Juntendo University Graduate School of Medicine, Tokyo, Japan; Sportology Center, Juntendo University Graduate School of Medicine, Tokyo, Japan; Center for Therapeutic Innovations in Diabetes, Juntendo University Graduate School of Medicine, Tokyo, Japan; and Center for Molecular Diabetology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| |
Collapse
|
73
|
KUSANO Y, TSUJIHARA N, MASUI H, KOZAI H, TAKEUCHI W. Consumption of Japanese Yam Improves Lipid Metabolism in High-Cholesterol Diet-Fed Rats. J Nutr Sci Vitaminol (Tokyo) 2016; 62:350-360. [DOI: 10.3177/jnsv.62.350] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Yuri KUSANO
- College of Bioscience and Biotechnology, Chubu University
| | - Nobuko TSUJIHARA
- Faculty of Human Life and Environmental Sciences, Nagoya Women’s University
| | - Hironori MASUI
- Department of Human Life and Environmental Sciences, Mukogawa Women’s University
| | - Hana KOZAI
- College of Bioscience and Biotechnology, Chubu University
| | - Wakako TAKEUCHI
- Faculty of Human Life and Environmental Sciences, Nagoya Women’s University
| |
Collapse
|
74
|
Insulin resistance: an additional risk factor in the pathogenesis of cardiovascular disease in type 2 diabetes. Heart Fail Rev 2015; 21:11-23. [DOI: 10.1007/s10741-015-9515-6] [Citation(s) in RCA: 109] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
|
75
|
Regulation of skeletal muscle mitochondrial function by nuclear receptors: implications for health and disease. Clin Sci (Lond) 2015; 129:589-99. [PMID: 26186742 DOI: 10.1042/cs20150246] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Skeletal muscle metabolism is highly dependent on mitochondrial function, with impaired mitochondrial biogenesis associated with the development of metabolic diseases such as insulin resistance and type 2 diabetes. Mitochondria display substantial plasticity in skeletal muscle, and are highly sensitive to levels of physical activity. It is thought that physical activity promotes mitochondrial biogenesis in skeletal muscle through increased expression of genes encoded in both the nuclear and the mitochondrial genome; however, how this process is co-ordinated at the cellular level is poorly understood. Nuclear receptors (NRs) are key signalling proteins capable of integrating environmental factors and mitochondrial function, thereby providing a potential link between exercise and mitochondrial biogenesis. The aim of this review is to highlight the function of NRs in skeletal muscle mitochondrial biogenesis and discuss the therapeutic potential of NRs for the management and treatment of chronic metabolic disease.
Collapse
|
76
|
Wessels B, van den Broek NMA, Ciapaite J, Houten SM, Wanders RJA, Nicolay K, Prompers JJ. Carnitine supplementation in high-fat diet-fed rats does not ameliorate lipid-induced skeletal muscle mitochondrial dysfunction in vivo. Am J Physiol Endocrinol Metab 2015; 309:E670-8. [PMID: 26286868 DOI: 10.1152/ajpendo.00144.2015] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Accepted: 08/17/2015] [Indexed: 12/24/2022]
Abstract
Muscle lipid overload and the associated accumulation of lipid intermediates play an important role in the development of insulin resistance. Carnitine insufficiency is a common feature of insulin-resistant states and might lead to incomplete fatty acid oxidation and impaired export of lipid intermediates out of the mitochondria. The aim of the present study was to test the hypothesis that carnitine supplementation reduces high-fat diet-induced lipotoxicity, improves muscle mitochondrial function, and ameliorates insulin resistance. Wistar rats were fed either normal chow or a high-fat diet for 15 wk. One group of high-fat diet-fed rats was supplemented with 300 mg·kg(-1)·day(-1) L-carnitine during the last 8 wk. Muscle mitochondrial function was measured in vivo by (31)P magnetic resonance spectroscopy (MRS) and ex vivo by high-resolution respirometry. Muscle lipid status was determined by (1)H MRS (intramyocellular lipids) and tandem mass spectrometry (acylcarnitines). High-fat diet feeding induced insulin resistance and was associated with decreases in muscle and blood free carnitine, elevated levels of muscle lipids and acylcarnitines, and an increased number of muscle mitochondria that showed an improved capacity to oxidize fat-derived substrates when tested ex vivo. This was, however, not accompanied by an increase in muscle oxidative capacity in vivo, indicating that in vivo mitochondrial function was compromised. Despite partial normalization of muscle and blood free carnitine content, carnitine supplementation did not induce improvements in muscle lipid status, in vivo mitochondrial function, or insulin sensitivity. Carnitine insufficiency, therefore, does not play a major role in high-fat diet-induced muscle mitochondrial dysfunction in vivo.
Collapse
Affiliation(s)
- Bart Wessels
- Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, the Netherlands; and
| | - Nicole M A van den Broek
- Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, the Netherlands; and
| | - Jolita Ciapaite
- Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, the Netherlands; and
| | - Sander M Houten
- Laboratory Genetic Metabolic Diseases, Departments of Pediatrics and Clinical Chemistry, Academic Medical Center, Amsterdam, the Netherlands
| | - Ronald J A Wanders
- Laboratory Genetic Metabolic Diseases, Departments of Pediatrics and Clinical Chemistry, Academic Medical Center, Amsterdam, the Netherlands
| | - Klaas Nicolay
- Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, the Netherlands; and
| | - Jeanine J Prompers
- Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, the Netherlands; and
| |
Collapse
|
77
|
Abnormalities in three-dimensional capillary architecture and imbalance between vascular endothelial growth factor-A and thrombospondin-1 in soleus muscle of ovariectomized rat. Acta Histochem 2015; 117:605-11. [PMID: 26092525 DOI: 10.1016/j.acthis.2015.06.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2015] [Revised: 05/29/2015] [Accepted: 06/01/2015] [Indexed: 11/23/2022]
Abstract
Reduced ovarian hormone levels associated with menopause or ovariectomy (OVX) not only result in vascular dysfunction but also lead to structural abnormalities in capillaries. Therefore, the effect of OVX on the three-dimensional (3-D) architecture of capillary networks and the underlying molecular mechanisms were investigated in rat soleus muscle. Seven-week-old female Wistar rats were divided into the OVX and sham-treated (Sham) groups. The OVX group exhibited lower endurance exercise capacity compared to the sham group and resulted in decreased capillary diameter, number of anastomoses and capillary/anastomosis volume in soleus muscle, indicating 3-D structural abnormalities of capillary networks. Furthermore, OVX led to increased concentrations of thrombospondin-1 (TSP-1) protein and a decreased VEGF-A/TSP-1 ratio, an indicator of angio-adaptations, in soleus muscle compared with the Sham group. These results indicate OVX may induce 3-D capillary regression in soleus muscle through an imbalance between VEGF-A and TSP-1 expression, possibly associated with decreased exercise tolerance in ovariectomized rats.
Collapse
|
78
|
Zamora M, Pardo R, Villena JA. Pharmacological induction of mitochondrial biogenesis as a therapeutic strategy for the treatment of type 2 diabetes. Biochem Pharmacol 2015. [PMID: 26212547 DOI: 10.1016/j.bcp.2015.06.032] [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] [Indexed: 12/18/2022]
Abstract
Defects in mitochondrial oxidative function have been associated with the onset of type 2 diabetes. Although the causal relationship between mitochondrial dysfunction and diabetes has not been fully established, numerous studies indicate that improved glucose homeostasis achieved via lifestyle interventions, such as exercise or calorie restriction, is tightly associated with increased mitochondrial biogenesis and oxidative function. Therefore, it is conceivable that potentiating mitochondrial biogenesis by pharmacological means could constitute an efficacious therapeutic strategy that would particularly benefit those diabetic patients who cannot adhere to comprehensive programs based on changes in lifestyle or that require a relatively rapid improvement in their diabetic status. In this review, we discuss several pharmacological targets and drugs that modulate mitochondrial biogenesis as well as their potential use as treatments for insulin resistance and diabetes.
Collapse
Affiliation(s)
- Mònica Zamora
- Cell Biology Group, Department of Experimental and Health Sciences, Universitat Pompeu Fabra, CIBER on Neurodegenerative Diseases (CIBERNED), Barcelona, Spain
| | - Rosario Pardo
- Laboratory of Metabolism and Obesity, Vall d'Hebron-Institut de Recerca, Universitat Autònoma de Barcelona, CIBER on Diabetes and Associated Metabolic Diseases (CIBERDEM), Barcelona, Spain
| | - Josep A Villena
- Laboratory of Metabolism and Obesity, Vall d'Hebron-Institut de Recerca, Universitat Autònoma de Barcelona, CIBER on Diabetes and Associated Metabolic Diseases (CIBERDEM), Barcelona, Spain.
| |
Collapse
|
79
|
Alvarado-Vásquez N. Circulating cell-free mitochondrial DNA as the probable inducer of early endothelial dysfunction in the prediabetic patient. Exp Gerontol 2015; 69:70-8. [PMID: 26026597 DOI: 10.1016/j.exger.2015.05.010] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Revised: 05/09/2015] [Accepted: 05/25/2015] [Indexed: 12/16/2022]
Abstract
Recent evidence has shown that 346million people in the world have diabetes mellitus (DM); this number will increase to 439million by 2030. In addition, current data indicate an increase in DM cases in the population between 40 and 59years of age. Diabetes is associated with the development of micro- and macro-vascular complications, derived from chronic hyperglycemia on the endothelium. Some reports demonstrate that people in a prediabetic state have a major risk of developing early endothelial dysfunction (ED). Today, it is accepted that individuals considered as prediabetic patients are in a pro-inflammatory state associated with endothelial and mitochondrial dysfunction. It is important to mention that impaired mitochondrial functionality has been linked to endothelial apoptosis and release of mitochondrial DNA (mtDNA) in patients with sepsis, cardiac disease, or atherosclerosis. This free mtDNA could promote ED, as well as other side effects on the vascular system through the activation of the toll-like receptor 9 (TLR9). TLR9 is expressed in different cell types (e.g., T or B lymphocytes, mastocytes, and epithelial and endothelial cells). It is localized intracellularly and recognizes non-methylated dinucleotides of viral, bacterial, and mitochondrial DNA. Recently, it has been reported that TLR9 is associated with the pathogenesis of lupus erythematosus, rheumatoid arthritis, and autoimmune diabetes. In this work, it is hypothesized that the increase in the levels of circulating mtDNA is the trigger of early ED in the prediabetic patient, and later on in the older patient with diabetes, through activation of the TLR9 present in the endothelium.
Collapse
Affiliation(s)
- Noé Alvarado-Vásquez
- Department of Biochemistry, National Institute of Respiratory Diseases "Ismael Cosío Villegas", Calz. de Tlalpan 4502, Col. Sección XVI, 14080 Mexico, D.F., Mexico, Mexico.
| |
Collapse
|
80
|
Muscular interleukin-6 differentially regulates skeletal muscle adaptation to high-fat diet in a sex-dependent manner. Cytokine 2015; 74:145-51. [PMID: 25982555 DOI: 10.1016/j.cyto.2015.04.018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Revised: 04/23/2015] [Accepted: 04/28/2015] [Indexed: 12/25/2022]
Abstract
Interleukin-6 (IL-6) is now known to be not only a major cytokine controlling the immune system but also basic physiological variables such as body weight and metabolism. We recently reported that muscle-specific interleukin-6 deletion influences body weight and body fat in a sex-dependent manner in mice. When compared with littermate floxed controls, males gained less weight whereas females gained more weight after a 12-week high-fat diet treatment (HFD). We herewith report gender-differences of HFD treatment on fast and slow skeletal muscle in muscle-specific IL-6 deficient mice. While gross muscle architecture was normal, in males, HFD resulted in an increased proportion of medium-large size myofibers which was prevented by muscle IL-6 deletion. No modifications of fiber size were observed in females. HFD induced a fiber-type switching in tibialis muscle, increasing the proportion of fast-oxidative fibers and decreasing the fast-glycolytic fibers in female mice which were dependent on muscle IL-6. No changes of fiber types were detected in males. Finally, HFD was associated with increased collagen deposition in both sexes and muscle types. However, this effect was only associated to the presence of muscular IL-6 only on the slow soleus muscle in males. The results demonstrate sex-dependent effects of both HFD and muscle IL-6 deficiency in skeletal muscle.
Collapse
|
81
|
Hawley JA, Morton JP. Ramping up the signal: promoting endurance training adaptation in skeletal muscle by nutritional manipulation. Clin Exp Pharmacol Physiol 2015; 41:608-13. [PMID: 25142094 DOI: 10.1111/1440-1681.12246] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Revised: 04/16/2014] [Accepted: 04/24/2014] [Indexed: 11/30/2022]
Abstract
Mitochondrial biogenesis in skeletal muscle results from the cumulative effect of transient increases in mRNA transcripts encoding mitochondrial proteins in response to repeated exercise sessions. This process requires the coordinated expression of both nuclear and mitochondrial (mt) DNA genomes and is regulated, for the most part, by the peroxisome proliferator-activated receptor γ coactivator 1α. Several other exercise-inducible proteins also play important roles in promoting an endurance phenotype, including AMP-activated protein kinase, p38 mitogen-activated protein kinase and tumour suppressor protein p53. Commencing endurance-based exercise with low muscle glycogen availability results in greater activation of many of these signalling proteins compared with when the same exercise is undertaken with normal glycogen concentration, suggesting that nutrient availability is a potent signal that can modulate the acute cellular responses to a single bout of exercise. When exercise sessions are repeated in the face of low glycogen availability (i.e. chronic training), the phenotypic adaptations resulting from such interventions are also augmented.
Collapse
Affiliation(s)
- John A Hawley
- Exercise & Nutrition Research Group, School of Exercise Sciences, Australian Catholic University, Melbourne, Vic., Australia; Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, UK
| | | |
Collapse
|
82
|
Ishizawa R, Masuda K, Sakata S, Nakatani A. Effects of different fatty acid chain lengths on fatty acid oxidation-related protein expression levels in rat skeletal muscles. J Oleo Sci 2015; 64:415-21. [PMID: 25766930 DOI: 10.5650/jos.ess14199] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Skeletal muscles can adapt to dietary interventions that affect energy metabolism. Dietary intake of medium-chain fatty acids (MCFAs) enhances mitochondrial oxidation of fatty acids (FAO) in type IIa skeletal muscle fibers. However, the effect of MCFAs diet on mitochondrial or cytoplasmic FAO-related protein expression levels in different types of muscle fibers remains unclear. This study aims to examine the effects of a high-fat diet, containing MCFAs, on mitochondrial enzyme activities and heart-type fatty acid-binding protein (H-FABP) levels in different types of skeletal muscle fibers. Five-week-old male Wistar rats were assigned to one of the following three dietary conditions: standard chow (SC, 12% of calories from fat), high-fat MCFA, or high-fat long-chain fatty acids (LCFAs) diet (60% of calories from fat for both). The animals were provided food and water ad libitum for 4 weeks, following which citrate synthase (CS) activity and H-FABP concentration were analyzed. The epididymal fat pads (EFP) were significantly smaller in the MCFA group than in the LCFA group (p < 0.05). MCFA-fed group displayed an increase in CS activity compared with that observed in SC-fed controls in all types of skeletal muscle fibers (triceps, surface portion of gastrocnemius (gasS), deep portion of gastrocnemius (gasD), and soleus; p < 0.05,). H-FABP concentration was significantly higher in the LCFA group than in both the SC-fed and MCFA-fed groups (triceps, gasS, gasD, and soleus; p < 0.05,). However, no significant difference was observed in the H-FABP concentrations between the SC-fed and MCFA-fed groups. The results of this study showed that the MCFA diet can increase the expression of the mitochondrial enzyme CS, but not that of H-FABP, in both fast- and slow-twitch muscle fibers, suggesting that H-FABP expression is dependent on the chain length of fatty acids in the cytoplasm of skeletal muscles cells.
Collapse
Affiliation(s)
- Rie Ishizawa
- Graduate School of Natural Sciences and Technology, Kanazawa University, Kanazawa, 920-1192, Japan; Department of Exercise Physiology, Nara University of Education, Nara, 630-8528, Japan
| | | | | | | |
Collapse
|
83
|
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: 354] [Impact Index Per Article: 39.3] [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.
Collapse
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
| |
Collapse
|
84
|
Henique C, Mansouri A, Vavrova E, Lenoir V, Ferry A, Esnous C, Ramond E, Girard J, Bouillaud F, Prip‐Buus C, Cohen I. Increasing mitochondrial muscle fatty acid oxidation induces skeletal muscle remodeling toward an oxidative phenotype. FASEB J 2015; 29:2473-83. [DOI: 10.1096/fj.14-257717] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Accepted: 02/13/2015] [Indexed: 12/17/2022]
Affiliation(s)
- Carole Henique
- Institut National de la Santé et de la Recherche Médicale (INSERM)U1016Institut CochinParisFrance
- Centre National de la Recherche Scientifique (CNRS)Unité Mixte de Recherche (UMR)8104ParisFrance
- Université Paris DescartesSorbonne Paris CitéParisFrance
| | - Abdelhak Mansouri
- Institut National de la Santé et de la Recherche Médicale (INSERM)U1016Institut CochinParisFrance
- Centre National de la Recherche Scientifique (CNRS)Unité Mixte de Recherche (UMR)8104ParisFrance
- Université Paris DescartesSorbonne Paris CitéParisFrance
| | - Eliska Vavrova
- Institut National de la Santé et de la Recherche Médicale (INSERM)U1016Institut CochinParisFrance
- Centre National de la Recherche Scientifique (CNRS)Unité Mixte de Recherche (UMR)8104ParisFrance
- Université Paris DescartesSorbonne Paris CitéParisFrance
| | - Véronique Lenoir
- Institut National de la Santé et de la Recherche Médicale (INSERM)U1016Institut CochinParisFrance
- Centre National de la Recherche Scientifique (CNRS)Unité Mixte de Recherche (UMR)8104ParisFrance
- Université Paris DescartesSorbonne Paris CitéParisFrance
| | - Arnaud Ferry
- Université Paris DescartesSorbonne Paris CitéParisFrance
- INSERM U974, CNRS UMR 7215Université Pierre et Marie Curie UMRS 974Institut de MyologieParisFrance
| | - Catherine Esnous
- Institut National de la Santé et de la Recherche Médicale (INSERM)U1016Institut CochinParisFrance
- Centre National de la Recherche Scientifique (CNRS)Unité Mixte de Recherche (UMR)8104ParisFrance
- Université Paris DescartesSorbonne Paris CitéParisFrance
| | - Elodie Ramond
- Institut National de la Santé et de la Recherche Médicale (INSERM)U1016Institut CochinParisFrance
- Centre National de la Recherche Scientifique (CNRS)Unité Mixte de Recherche (UMR)8104ParisFrance
- Université Paris DescartesSorbonne Paris CitéParisFrance
| | - Jean Girard
- Institut National de la Santé et de la Recherche Médicale (INSERM)U1016Institut CochinParisFrance
- Centre National de la Recherche Scientifique (CNRS)Unité Mixte de Recherche (UMR)8104ParisFrance
- Université Paris DescartesSorbonne Paris CitéParisFrance
| | - Frédéric Bouillaud
- Institut National de la Santé et de la Recherche Médicale (INSERM)U1016Institut CochinParisFrance
- Centre National de la Recherche Scientifique (CNRS)Unité Mixte de Recherche (UMR)8104ParisFrance
- Université Paris DescartesSorbonne Paris CitéParisFrance
| | - Carina Prip‐Buus
- Institut National de la Santé et de la Recherche Médicale (INSERM)U1016Institut CochinParisFrance
- Centre National de la Recherche Scientifique (CNRS)Unité Mixte de Recherche (UMR)8104ParisFrance
- Université Paris DescartesSorbonne Paris CitéParisFrance
| | - Isabelle Cohen
- Institut National de la Santé et de la Recherche Médicale (INSERM)U1016Institut CochinParisFrance
- Centre National de la Recherche Scientifique (CNRS)Unité Mixte de Recherche (UMR)8104ParisFrance
- Université Paris DescartesSorbonne Paris CitéParisFrance
| |
Collapse
|
85
|
Gao AW, Cantó C, Houtkooper RH. Mitochondrial response to nutrient availability and its role in metabolic disease. EMBO Mol Med 2014; 6:580-9. [PMID: 24623376 PMCID: PMC4023882 DOI: 10.1002/emmm.201303782] [Citation(s) in RCA: 104] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Metabolic inflexibility is defined as an impaired capacity to switch between different energy substrates and is a hallmark of insulin resistance and type 2 diabetes mellitus (T2DM). Hence, understanding the mechanisms underlying proper metabolic flexibility is key to prevent the development of metabolic disease and physiological deterioration. An important downstream player in the effects of metabolic flexibility is the mitochondrion. The objective of this review was to describe how mitochondrial metabolism adapts to limited nutrient situations or caloric excess by changes in mitochondrial function or biogenesis, as well as to define the mechanisms propelling these changes. Altogether, this should pinpoint key regulatory points by which metabolic flexibility might be ameliorated in situations of metabolic disease.
Collapse
Affiliation(s)
- Arwen W Gao
- Laboratory Genetic Metabolic Diseases, Academic Medical Center, Amsterdam, The Netherlands
| | | | | |
Collapse
|
86
|
Picklo MJ, Thyfault JP. Vitamin E and vitamin C do not reduce insulin sensitivity but inhibit mitochondrial protein expression in exercising obese rats. Appl Physiol Nutr Metab 2014; 40:343-52. [PMID: 25761734 DOI: 10.1139/apnm-2014-0302] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Controversy exists as to whether supplementation with the antioxidants vitamin E and vitamin C blocks adaptation to exercise. Exercise is a first-line means to treat obesity and its complications. While diet-induced obesity alters mitochondrial function and induces insulin resistance (IR), no data exist as to whether supplementation with vitamin E and vitamin C modify responses to exercise in pre-existing obesity. We tested the hypothesis that dietary supplementation with vitamin E (0.4 g α-tocopherol acetate/kg) and vitamin C (0.5 g/kg) blocks exercise-induced improvements on IR and mitochondrial content in obese rats maintained on a high-fat (45% fat energy (en)) diet. Diet-induced obese, sedentary rats had a 2-fold higher homeostasis model assessment of insulin resistance and larger insulin area under the curve following glucose tolerances test than rats fed a low-fat (10% fat en) diet. Exercising (12 weeks at 5 times per week in a motorized wheel) of obese rats normalized IR indices, an effect not modified by vitamin E and vitamin C. Vitamin E and vitamin C supplementation with exercise elevated mtDNA content in adipose and skeletal muscle to a greater extent (20%) than exercise alone in a depot-specific manner. On the other hand, vitamin C and vitamin E decreased exercise-induced increases in mitochondrial protein content for complex I (40%) and nicotinamide nucleotide transhydrogenase (35%) in a muscle-dependent manner. These data indicate that vitamin E and vitamin C supplementation in obese rodents does not modify exercise-induced improvements in insulin sensitivity but that changes in mitochondrial biogenesis and mitochondrial protein expression may be modified by antioxidant supplementation.
Collapse
Affiliation(s)
- Matthew J Picklo
- USDA-ARS Grand Forks Human Nutrition Research Center, 2420 2nd Avenue North, Grand Forks, ND 58201, USA
| | | |
Collapse
|
87
|
Collino M, Benetti E, Rogazzo M, Chiazza F, Mastrocola R, Nigro D, Cutrin JC, Aragno M, Fantozzi R, Minetto MA, Thiemermann C. A non-erythropoietic peptide derivative of erythropoietin decreases susceptibility to diet-induced insulin resistance in mice. Br J Pharmacol 2014; 171:5802-15. [PMID: 25164531 PMCID: PMC4290718 DOI: 10.1111/bph.12888] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Revised: 08/01/2014] [Accepted: 08/11/2014] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND AND PURPOSE The haematopoietic activity of erythropoietin (EPO) is mediated by the classic EPO receptor (EpoR) homodimer, whereas tissue-protective effects are mediated by a heterocomplex between EpoR and the β-common receptor (βcR). Here, we investigated the effects of a novel, selective ligand of this heterocomplex - pyroglutamate helix B surface peptide (pHBSP) - in mice fed a diet enriched in sugars and saturated fats. EXPERIMENTAL APPROACH Male C57BL/6J mice were fed a high-fat high-sucrose diet (HFHS) for 22 weeks. pHBSP (30 μg·kg(-1) s.c.) was administered for the last 11 weeks. Biochemical assays, histopathological and immunohistochemical examinations and Western blotting were performed on serum and target organs (liver, kidney and skeletal muscle). KEY RESULTS Mice fed with HFHS diet exhibited insulin resistance, hyperlipidaemia, hepatic lipid accumulation and kidney dysfunction. In gastrocnemius muscle, HFHS impaired the insulin signalling pathway and reduced membrane translocation of glucose transporter type 4 and glycogen content. Treatment with pHBSP ameliorated renal function, reduced hepatic lipid deposition, and normalized serum glucose and lipid profiles. These effects were associated with an improvement in insulin sensitivity and glucose uptake in skeletal muscle. Diet-induced overproduction of the myokines IL-6 and fibroblast growth factor-21 were attenuated by pHBSP and, most importantly, pHBSP markedly enhanced mitochondrial biogenesis in skeletal muscle. CONCLUSIONS AND IMPLICATIONS Chronic treatment of mice with an EPO derivative, devoid of haematopoietic effects, improved metabolic abnormalities induced by a high-fat high-sucrose diet, by affecting several levels of the insulin signalling and inflammatory cascades within skeletal muscle, while enhancing mitochondrial biogenesis.
Collapse
Affiliation(s)
- M Collino
- Department of Drug Science and Technology, University of TurinTurin, Italy
| | - E Benetti
- Department of Drug Science and Technology, University of TurinTurin, Italy
| | - M Rogazzo
- Department of Drug Science and Technology, University of TurinTurin, Italy
| | - F Chiazza
- Department of Drug Science and Technology, University of TurinTurin, Italy
| | - R Mastrocola
- Department of Clinical and Biological Sciences, University of TurinTurin, Italy
| | - D Nigro
- Department of Clinical and Biological Sciences, University of TurinTurin, Italy
| | - J C Cutrin
- Department of Biotechnology and Sciences for the Health, University of TurinItaly
- Instituto de Investigaciones Cardiológicas, ININCA-CONICETBuenos Aires, Argentina
| | - M Aragno
- Department of Clinical and Biological Sciences, University of TurinTurin, Italy
| | - R Fantozzi
- Department of Drug Science and Technology, University of TurinTurin, Italy
| | - M A Minetto
- Division of Endocrinology, Diabetology and Metabolism, Department of Medical Sciences, University of TurinTurin, Italy
| | - C Thiemermann
- Centre for Translational Medicine and Therapeutics, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of LondonLondon, UK
| |
Collapse
|
88
|
Zoladz JA, Grassi B, Majerczak J, Szkutnik Z, Korostyński M, Grandys M, Jarmuszkiewicz W, Korzeniewski B. Mechanisms responsible for the acceleration of pulmonary V̇o2 on-kinetics in humans after prolonged endurance training. Am J Physiol Regul Integr Comp Physiol 2014; 307:R1101-14. [DOI: 10.1152/ajpregu.00046.2014] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The effect of prolonged endurance training on the pulmonary V̇o2 on- and off-kinetics in humans, in relation to muscle mitochondria biogenesis, is investigated. Eleven untrained physically active men (means ± SD: age 22.4 ± 1.5 years, V̇o2peak 3,187 ± 479 ml/min) performed endurance cycling training (4 sessions per week) lasting 20 wk. Training shortened τp of the pulmonary V̇o2 on-kinetics during moderate-intensity cycling by ∼19% from 28.3 ± 5.2 to 23.0 ± 4.0 s ( P = 0.005). τp of the pulmonary V̇o2 off-kinetics decreased by ∼11% from 33.7 ± 7.2 to 30.0 ± 6.6 ( P = 0.02). Training increased (in vastus lateralis muscle) mitochondrial DNA copy number in relation to nuclear DNA (mtDNA/nDNA) (+53%) ( P = 0.014), maximal citrate synthase (CS) activity (+38%), and CS protein content (+38%) ( P = 0.004), whereas maximal cytochrome c oxidase (COX) activity after training tended to be only slightly (+5%) elevated ( P = 0.08). By applying to the experimental data, our computer model of oxidative phosphorylation (OXPHOS) and using metabolic control analysis, we argue that COX activity is a much better measure of OXPHOS intensity than CS activity. According to the model, in the present study a training-induced increase in OXPHOS activity accounted for about 0–10% of the decrease in τp of muscle and pulmonary V̇o2 for the on-transient, whereas the remaining 90–100% is caused by an increase in each-step parallel activation of OXPHOS.
Collapse
Affiliation(s)
- Jerzy A. Zoladz
- Department of Muscle Physiology, Chair of Physiology and Biochemistry, Faculty of Rehabilitation, University School of Physical Education, Kraków, Poland
| | - Bruno Grassi
- Dipartimento di Scienze Mediche e Biologiche, Università degli Studi di Udine, Udine, Italy
| | - Joanna Majerczak
- Department of Muscle Physiology, Chair of Physiology and Biochemistry, Faculty of Rehabilitation, University School of Physical Education, Kraków, Poland
| | | | - Michal Korostyński
- Department of Molecular Neuropharmacology, Institute of Pharmacology, Polish Academy of Sciences, Kraków, Poland
| | - Marcin Grandys
- Department of Muscle Physiology, Chair of Physiology and Biochemistry, Faculty of Rehabilitation, University School of Physical Education, Kraków, Poland
| | | | - Bernard Korzeniewski
- Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Kraków, Poland
| |
Collapse
|
89
|
Kawaguchi M, Tamura Y, Kakehi S, Takeno K, Sakurai Y, Watanabe T, Funayama T, Sato F, Ikeda S, Ogura Y, Saga N, Naito H, Fujitani Y, Kanazawa A, Kawamori R, Watada H. Association between expression of FABPpm in skeletal muscle and insulin sensitivity in intramyocellular lipid-accumulated nonobese men. J Clin Endocrinol Metab 2014; 99:3343-52. [PMID: 24937540 DOI: 10.1210/jc.2014-1896] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
CONTEXT Intramyocellular lipid (IMCL) accumulation is observed in both insulin-resistant subjects and insulin-sensitive endurance athletes (athlete's paradox). We hypothesized that the expression pattern of fatty acid transporters may influence oxidative capacity and determine the association between IMCL and insulin resistance. OBJECTIVE The objective of the study was to investigate the muscle expression of fatty acid transporters and their function related to insulin sensitivity in IMCL-accumulated subjects. DESIGN AND SETTING The study subjects were 36 nonobese healthy men. Their IMCL levels were measured by (1)H-magnetic resonance spectroscopy, and their insulin sensitivity was evaluated by steady-state glucose infusion rate (GIR) during a euglycemic-hyperinsulinemic clamp. Gene expression levels in the vastus lateralis were evaluated by quantitative RT-PCR. We compared the clinical phenotypes and the expression levels of genes involved in lipid metabolism in skeletal muscle between IMCL-accumulated high-GIR (H-GIR) subjects (n = 8) and low-GIR subjects (n = 9). The functions of candidate fatty acid transporters were determined by in vitro analyses. RESULTS Compared with the low-GIR group, body fat was lower and maximum oxygen uptake was higher in the H-GIR group. Several lipid oxidation genes in muscle were up-regulated in the H-GIR group, and this was associated with increased expression of higher plasma membrane-associated fatty acid-binding protein (FABPpm) and decreased expression of fatty acid transport protein (FATP)-1. Overexpression of FABPpm in C2C12 myotubes increased fatty acid oxidation coupled with the elevated expression of genes related to fatty acid oxidation. These changes were not observed in FATP1-overexpressed myotubes. CONCLUSIONS Differences in the gene expression of fatty acid transporters may, at least in part, affect insulin sensitivity in IMCL-accumulated nonobese men.
Collapse
Affiliation(s)
- Minako Kawaguchi
- Department of Metabolism and Endocrinology (M.K., Y.T., S.K., K.T., Y.S., T.W., T.F., F.S., S.I., Y.F., A.K., R.K., H.W.), Sportology Center (Y.T., S.K., S.I., R.K., H.W.), Center for Therapeutic Innovations in Diabetes (H.W.), and Center for Molecular Diabetology (H.W.), Juntendo University Graduate School of Medicine, Tokyo 113-8421, Japan; and Institute of Health and Sports Science and Medicine (Y.O., N.S., H.N.) and Department of Exercise Physiology (Y.O., N.S., H.N.), Juntendo University Graduate School of Health and Sports Science, Chiba 270-1695, Japan
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
90
|
Lipina C, Irving AJ, Hundal HS. Mitochondria: a possible nexus for the regulation of energy homeostasis by the endocannabinoid system? Am J Physiol Endocrinol Metab 2014; 307:E1-13. [PMID: 24801388 DOI: 10.1152/ajpendo.00100.2014] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The endocannabinoid system (ECS) regulates numerous cellular and physiological processes through the activation of receptors targeted by endogenously produced ligands called endocannabinoids. Importantly, this signaling system is known to play an important role in modulating energy balance and glucose homeostasis. For example, current evidence indicates that the ECS becomes overactive during obesity whereby its central and peripheral stimulation drives metabolic processes that mimic the metabolic syndrome. Herein, we examine the role of the ECS in modulating the function of mitochondria, which play a pivotal role in maintaining cellular and systemic energy homeostasis, in large part due to their ability to tightly coordinate glucose and lipid utilization. Because of this, mitochondrial dysfunction is often associated with peripheral insulin resistance and glucose intolerance as well as the manifestation of excess lipid accumulation in the obese state. This review aims to highlight the different ways through which the ECS may impact upon mitochondrial abundance and/or oxidative capacity and, where possible, relate these findings to obesity-induced perturbations in metabolic function. Furthermore, we explore the potential implications of these findings in terms of the pathogenesis of metabolic disorders and how these may be used to strategically develop therapies targeting the ECS.
Collapse
Affiliation(s)
- Christopher Lipina
- Division of Cell Signalling and Immunology, Sir James Black Centre, College of Life Sciences, University of Dundee, Dundee, Scotland, United Kingdom
| | - Andrew J Irving
- Division of Cell Signalling and Immunology, Sir James Black Centre, College of Life Sciences, University of Dundee, Dundee, Scotland, United Kingdom
| | - Harinder S Hundal
- Division of Cell Signalling and Immunology, Sir James Black Centre, College of Life Sciences, University of Dundee, Dundee, Scotland, United Kingdom
| |
Collapse
|
91
|
Takada S, Hirabayashi K, Kinugawa S, Yokota T, Matsushima S, Suga T, Kadoguchi T, Fukushima A, Homma T, Mizushima W, Masaki Y, Furihata T, Katsuyama R, Okita K, Tsutsui H. Pioglitazone ameliorates the lowered exercise capacity and impaired mitochondrial function of the skeletal muscle in type 2 diabetic mice. Eur J Pharmacol 2014; 740:690-6. [PMID: 24964389 DOI: 10.1016/j.ejphar.2014.06.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Revised: 06/07/2014] [Accepted: 06/16/2014] [Indexed: 02/06/2023]
Abstract
We have reported that exercise capacity is reduced in high fat diet (HFD)-induced diabetic mice, and that this reduction is associated with impaired mitochondrial function in skeletal muscle (SKM). However, it remains to be clarified whether the treatment of diabetes ameliorates the reduced exercise capacity. Therefore, we examined whether an insulin-sensitizing drug, pioglitazone, could improve exercise capacity in HFD mice. C57BL/6J mice were fed a normal diet (ND) or HFD, then treated with or without pioglitazone (3 mg/kg/day) to yield the following 4 groups: ND+vehicle, ND+pioglitazone, HFD+vehicle, and HFD+pioglitazone (n=10 each). After 8 weeks, body weight, plasma glucose, and insulin in the HFD+vehicle were significantly increased compared to the ND+vehicle group. Pioglitazone normalized the insulin levels in HFD-fed mice, but did not affect the body weight or plasma glucose. Exercise capacity determined by treadmill tests was significantly reduced in the HFD+vehicle, and this reduction was almost completely ameliorated in HFD+pioglitazone mice. ADP-dependent mitochondrial respiration, complex I and III activities, and citrate synthase activity were significantly decreased in the SKM of the HFD+vehicle animals, and these decreases were also attenuated by pioglitazone. NAD(P)H oxidase activity was significantly increased in the HFD+vehicle compared with the ND+vehicle, and this increase was ameliorated in HFD+pioglitazone mice. Pioglitazone improved the exercise capacity in diabetic mice, which was due to the improvement in mitochondrial function and attenuation of oxidative stress in the SKM. Our data suggest that pioglitazone may be useful as an agent for the treatment of diabetes mellitus.
Collapse
Affiliation(s)
- Shingo Takada
- Department of Cardiovascular Medicine, Hokkaido University Graduate School of Medicine, Kita-15, Nishi-7, Kita-ku, Sapporo 060-8638, Japan; Research Fellow of the Japan Society for the Promotion of Science, Japan
| | - Kagami Hirabayashi
- Department of Cardiovascular Medicine, Hokkaido University Graduate School of Medicine, Kita-15, Nishi-7, Kita-ku, Sapporo 060-8638, Japan
| | - Shintaro Kinugawa
- Department of Cardiovascular Medicine, Hokkaido University Graduate School of Medicine, Kita-15, Nishi-7, Kita-ku, Sapporo 060-8638, Japan.
| | - Takashi Yokota
- Department of Cardiovascular Medicine, Hokkaido University Graduate School of Medicine, Kita-15, Nishi-7, Kita-ku, Sapporo 060-8638, Japan
| | - Shouji Matsushima
- Department of Cardiovascular Medicine, Hokkaido University Graduate School of Medicine, Kita-15, Nishi-7, Kita-ku, Sapporo 060-8638, Japan
| | - Tadashi Suga
- Faculty of Sport and Health Science, Ritsumeikan University, Kusatsu, Shiga, Japan
| | - Tomoyasu Kadoguchi
- Department of Cardiovascular Medicine, Hokkaido University Graduate School of Medicine, Kita-15, Nishi-7, Kita-ku, Sapporo 060-8638, Japan
| | - Arata Fukushima
- Department of Cardiovascular Medicine, Hokkaido University Graduate School of Medicine, Kita-15, Nishi-7, Kita-ku, Sapporo 060-8638, Japan
| | - Tsuneaki Homma
- Department of Cardiovascular Medicine, Hokkaido University Graduate School of Medicine, Kita-15, Nishi-7, Kita-ku, Sapporo 060-8638, Japan
| | - Wataru Mizushima
- Department of Cardiovascular Medicine, Hokkaido University Graduate School of Medicine, Kita-15, Nishi-7, Kita-ku, Sapporo 060-8638, Japan
| | - Yoshihiro Masaki
- Department of Cardiovascular Medicine, Hokkaido University Graduate School of Medicine, Kita-15, Nishi-7, Kita-ku, Sapporo 060-8638, Japan
| | - Takaaki Furihata
- Department of Cardiovascular Medicine, Hokkaido University Graduate School of Medicine, Kita-15, Nishi-7, Kita-ku, Sapporo 060-8638, Japan
| | - Ryoichi Katsuyama
- Department of Cardiovascular Medicine, Hokkaido University Graduate School of Medicine, Kita-15, Nishi-7, Kita-ku, Sapporo 060-8638, Japan
| | - Koichi Okita
- Department of Sport Education, Hokusho University, Ebetsu, Japan
| | - Hiroyuki Tsutsui
- Department of Cardiovascular Medicine, Hokkaido University Graduate School of Medicine, Kita-15, Nishi-7, Kita-ku, Sapporo 060-8638, Japan
| |
Collapse
|
92
|
Franko A, von Kleist-Retzow JC, Neschen S, Wu M, Schommers P, Böse M, Kunze A, Hartmann U, Sanchez-Lasheras C, Stoehr O, Huntgeburth M, Brodesser S, Irmler M, Beckers J, de Angelis MH, Paulsson M, Schubert M, Wiesner RJ. Liver adapts mitochondrial function to insulin resistant and diabetic states in mice. J Hepatol 2014; 60:816-23. [PMID: 24291365 DOI: 10.1016/j.jhep.2013.11.020] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2012] [Revised: 11/18/2013] [Accepted: 11/19/2013] [Indexed: 12/04/2022]
Abstract
BACKGROUND & AIMS To determine if diabetic and insulin-resistant states cause mitochondrial dysfunction in liver or if there is long term adaptation of mitochondrial function to these states, mice were (i) fed with a high-fat diet to induce obesity and T2D (HFD), (ii) had a genetic defect in insulin signaling causing whole body insulin resistance, but not full blown T2D (IR/IRS-1(+/-) mice), or (iii) were analyzed after treatment with streptozocin (STZ) to induce a T1D-like state. METHODS Hepatic lipid levels were measured by thin layer chromatography. Mitochondrial respiratory chain (RC) levels and function were determined by Western blot, spectrophotometric, oxygen consumption and proton motive force analysis. Gene expression was analyzed by real-time PCR and microarray. RESULTS HFD caused insulin resistance and hepatic lipid accumulation, but RC was largely unchanged. Livers from insulin resistant IR/IRS-1(+/-) mice had normal lipid contents and a normal RC, but mitochondria were less well coupled. Livers from severely hyperglycemic and hypoinsulinemic STZ mice had massively depleted lipid levels, but RC abundance was unchanged. However, liver mitochondria isolated from these animals showed increased abundance and activity of the RC, which was better coupled. CONCLUSIONS Insulin resistance, induced either by obesity or genetic manipulation and steatosis do not cause mitochondrial dysfunction in mouse liver. Also, mitochondrial dysfunction is not a prerequisite for liver steatosis. However, severe insulin deficiency and high blood glucose levels lead to an enhanced performance and better coupling of the RC. This may represent an adaptation to fuel overload and the high energy-requirement of an unsuppressed gluconeogenesis.
Collapse
Affiliation(s)
- Andras Franko
- Center for Physiology and Pathophysiology, Institute of Vegetative Physiology, University of Köln, 50931 Köln, Germany; Institute of Experimental Genetics, Helmholtz Zentrum München GmbH, 85764 Neuherberg, Germany; German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany
| | - Jürgen-Christoph von Kleist-Retzow
- Center for Physiology and Pathophysiology, Institute of Vegetative Physiology, University of Köln, 50931 Köln, Germany; Department of Pediatrics, University of Köln, 50924 Köln, Germany; Center for Molecular Medicine Cologne, CMMC, University of Köln, 50931 Köln, Germany
| | - Susanne Neschen
- Institute of Experimental Genetics, Helmholtz Zentrum München GmbH, 85764 Neuherberg, Germany; German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany
| | - Moya Wu
- Institute of Experimental Genetics, Helmholtz Zentrum München GmbH, 85764 Neuherberg, Germany; German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany
| | - Philipp Schommers
- Center for Physiology and Pathophysiology, Institute of Vegetative Physiology, University of Köln, 50931 Köln, Germany
| | - Marlen Böse
- Center for Physiology and Pathophysiology, Institute of Vegetative Physiology, University of Köln, 50931 Köln, Germany
| | - Alexander Kunze
- Department of Biochemistry, University of Köln, 50931 Köln, Germany
| | - Ursula Hartmann
- Department of Biochemistry, University of Köln, 50931 Köln, Germany
| | - Carmen Sanchez-Lasheras
- Department of Mouse Genetics and Metabolism, Institute for Genetics, University of Köln, 50674 Köln, Germany
| | - Oliver Stoehr
- Center for Endocrinology, Diabetes and Preventive Medicine, University of Köln, 50937 Köln, Germany
| | - Michael Huntgeburth
- Department of Internal Medicine III, University of Köln, 50937 Köln, Germany
| | - Susanne Brodesser
- Institute for Medical Microbiology, Immunology and Hygiene, University of Köln, 50935 Köln, Germany; Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), 50674 Köln, Germany
| | - Martin Irmler
- Institute of Experimental Genetics, Helmholtz Zentrum München GmbH, 85764 Neuherberg, Germany
| | - Johannes Beckers
- Institute of Experimental Genetics, Helmholtz Zentrum München GmbH, 85764 Neuherberg, Germany; German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany; Technische Universität München, WZW - Center of Life and Food Science Weihenstephan, Chair of Experimental Genetics, 85350 Freising-Weihenstephan, Germany
| | - Martin Hrabé de Angelis
- Institute of Experimental Genetics, Helmholtz Zentrum München GmbH, 85764 Neuherberg, Germany; German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany; Technische Universität München, WZW - Center of Life and Food Science Weihenstephan, Chair of Experimental Genetics, 85350 Freising-Weihenstephan, Germany
| | - Mats Paulsson
- Center for Molecular Medicine Cologne, CMMC, University of Köln, 50931 Köln, Germany; Department of Biochemistry, University of Köln, 50931 Köln, Germany; Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), 50674 Köln, Germany
| | - Markus Schubert
- Center for Molecular Medicine Cologne, CMMC, University of Köln, 50931 Köln, Germany; Center for Endocrinology, Diabetes and Preventive Medicine, University of Köln, 50937 Köln, Germany; Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), 50674 Köln, Germany.
| | - Rudolf J Wiesner
- Center for Physiology and Pathophysiology, Institute of Vegetative Physiology, University of Köln, 50931 Köln, Germany; Center for Molecular Medicine Cologne, CMMC, University of Köln, 50931 Köln, Germany; Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), 50674 Köln, Germany.
| |
Collapse
|
93
|
Stephenson EJ, Hawley JA. Mitochondrial function in metabolic health: a genetic and environmental tug of war. Biochim Biophys Acta Gen Subj 2013; 1840:1285-94. [PMID: 24345456 DOI: 10.1016/j.bbagen.2013.12.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Revised: 11/09/2013] [Accepted: 12/10/2013] [Indexed: 01/27/2023]
Abstract
BACKGROUND The increased prevalence of obesity and its co-morbidities and their strong association with inactivity have produced an 'exercise-deficient phenotype' in which individuals with a particular combination of disease-susceptible genes collide with environmental influences to cross a biological 'threshold' that ultimately manifests as overt clinical conditions (i.e., risk-factors for disease states). These risk-factors have been linked to impairments in skeletal muscle mitochondrial function. SCOPE OF REVIEW The question of whether 'inborn' mitochondrial deficiencies and/or defective mitochondrial metabolism contribute to metabolic disease, or if environmental factors are the major determinant, will be examined. MAJOR CONCLUSIONS We contend that impaired whole-body insulin resistance along with impaired skeletal muscle handling of carbohydrate and lipid fuels (i.e., metabolic inflexibility) is associated with a reduced skeletal muscle mitochondrial content which, in large part, is a maladaptive response to an 'inactivity cycle' which predisposes to a reduced level of habitual physical activity. While genetic components play a role in the pathogenesis of metabolic disease, exercise is a powerful environmental stimulus capable of restoring the metabolic flexibility of fuel selection and reduces risk-factors for metabolic disease in genetically-susceptible individuals. GENERAL SIGNIFICANCE Given the apathy towards voluntary physical activity in most Western societies, it is clear that there is an urgent need for innovative, clinically-effective exercise strategies, coupled with changes in current attitudes and methods of delivering exercise prescription and dietary advice, in order to improve metabolic health and reduce metabolic disease risk at the population level. This article is part of a Special Issue entitled Frontiers of Mitochondrial Research.
Collapse
Affiliation(s)
- Erin J Stephenson
- Children's Foundation Research Institute, Le Bonheur Children's Hospital, Department of Pediatrics, University of Tennessee Health Science Center, Memphis, Tennessee, U.S.A..
| | - John A Hawley
- Faculty of Health Sciences, Australian Catholic University, Fitzroy, Australia; Research Institute for Sports and Exercise, Liverpool John Moores University, Liverpool United Kingdom.
| |
Collapse
|
94
|
Holloszy JO. Regulation of mitochondrial biogenesis and GLUT4 expression by exercise. Compr Physiol 2013; 1:921-40. [PMID: 23737207 DOI: 10.1002/cphy.c100052] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Endurance exercise training can induce large increases mitochondria and the GLUT4 isoform of the glucose transporter in skeletal muscle. For a long time after the discovery in the 1960s that exercise results in an increase in muscle mitochondria, there was no progress in elucidation of the mechanisms involved. The reason for this lack of progress was that nothing was known regarding how expression of the genes-encoding mitochondrial proteins is coordinately regulated. This situation changed rapidly after discovery of transcription factors that control transcription of genes-encoding mitochondrial proteins and, most importantly, the discovery of peroxisome proliferator-gamma coactivator-1α (PGC-1α). This transcription coactivator binds to and activates transcription factors that regulate transcription of genes-encoding mitochondrial proteins. Thus, PGC-1α activates and coordinates mitochondrial biogenesis. It is now known that exercise rapidly activates and induces increased expression of PGC-1α. The exercise-generated signals that lead to PGC-1α activation and increased expression are the increases in cytosolic Ca(2+) and decreases in ATP and creatine phosphate (∼P). Ca(2+) mediates its effect by activating CAMKII, while the decrease in ∼P mediates its effect via activation of AMPK. Expression of the GLUT4 isoform of the glucose transporter is regulated in parallel with mitochondrial biogenesis via the same signaling pathways. This review describes what is known regarding the regulation of mitochondrial biogenesis and GLUT4 expression by exercise. A major component of this review deals with the physiological and metabolic consequences of the exercise-induced increase in mitochondria and GLUT4.
Collapse
Affiliation(s)
- John O Holloszy
- Division of Geriatrics and Nutritional Sciences, Washington University School of Medicine, St. Louis, Missouri, USA.
| |
Collapse
|
95
|
García-Ruiz C, Baulies A, Mari M, García-Rovés PM, Fernandez-Checa JC. Mitochondrial dysfunction in non-alcoholic fatty liver disease and insulin resistance: Cause or consequence? Free Radic Res 2013; 47:854-68. [DOI: 10.3109/10715762.2013.830717] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
|
96
|
Warda M, Kim HK, Kim N, Ko KS, Rhee BD, Han J. A matter of life, death and diseases: mitochondria from a proteomic perspective. Expert Rev Proteomics 2013; 10:97-111. [PMID: 23414362 DOI: 10.1586/epr.12.69] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Mitochondria are highly ordered, integrated organelles that energize cellular activities and contribute to programmed death by initiating disciplined apoptotic cascades. This review seeks to clarify our understanding of mitochondrial structural-functional integrity beyond the resolved nuclear genome by unraveling the dynamic mitochondrial proteome and elucidating proteome/genome interplay. The roles of mechanochemical coupling between mitoskeleton and cytoskeleton and crosstalk with other organelles in orchestrating cellular outcomes are explained. The authors also review the modulation of mitochondrial-related oxidative stress on apoptosis and cancer development and the context is applied to interpret pathogenetic events in neurodegenerative disorders and cardiovascular diseases. The accumulated proteomics evidence is used to describe the integral role that mitochondria play and how they influence other intracellular organelles. Possible mitochondrial-targeted therapeutic interventions are also discussed.
Collapse
Affiliation(s)
- Mohamad Warda
- Biochemistry, Molecular Biology and Chemistry of Nutrition Department, Faculty of Veterinary Medicine, Cairo University, Giza, Egypt.
| | | | | | | | | | | |
Collapse
|
97
|
Lanza IR, Blachnio-Zabielska A, Johnson ML, Schimke JM, Jakaitis DR, Lebrasseur NK, Jensen MD, Sreekumaran Nair K, Zabielski P. Influence of fish oil on skeletal muscle mitochondrial energetics and lipid metabolites during high-fat diet. Am J Physiol Endocrinol Metab 2013; 304:E1391-403. [PMID: 23632634 PMCID: PMC4116354 DOI: 10.1152/ajpendo.00584.2012] [Citation(s) in RCA: 102] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Omega-3 polyunsaturated fatty acids (n-3 PUFAs) enhance insulin sensitivity and glucose homeostasis in rodent models of insulin resistance. These beneficial effects have been linked with anti-inflammatory properties, but emerging data suggest that the mechanisms may also converge on mitochondria. We evaluated the influence of dietary n-3 PUFAs on mitochondrial physiology and muscle lipid metabolites in the context of high-fat diet (HFD) in mice. Mice were fed control diets (10% fat), HFD (60% fat), or HFD with fish oil (HFD+FO, 3.4% kcal from n-3 PUFAs) for 10 wk. Body mass and fat mass increased similarly in HFD and HFD+FO, but n-3 PUFAs attenuated the glucose intolerance that developed with HFD and increased expression of genes that regulate glucose metabolism in skeletal muscle. Despite similar muscle triglyceride levels in HFD and HFD+FO, long-chain acyl-CoAs and ceramides were lower in the presence of fish oil. Mitochondrial abundance and oxidative capacity were similarly increased in HFD and HFD+FO compared with controls. Hydrogen peroxide production was similarly elevated in HFD and HFD+FO in isolated mitochondria but not in permeabilized muscle fibers, likely due to increased activity and expression of catalase. These results support a hypothesis that n-3 PUFAs protect glucose tolerance, in part by preventing the accumulation of bioactive lipid mediators that interfere with insulin action. Furthermore, the respiratory function of skeletal muscle mitochondria does not appear to be a major factor in sphingolipid accumulation, glucose intolerance, or the protective effects of n-3 PUFAs.
Collapse
Affiliation(s)
- Ian R Lanza
- Division of Endocrinology and Metabolism, Mayo Clinic College of Medicine, Rochester, Minnesota
| | | | | | | | | | | | | | | | | |
Collapse
|
98
|
Increased skeletal muscle mitochondrial efficiency in rats with fructose-induced alteration in glucose tolerance. Br J Nutr 2013; 110:1996-2003. [PMID: 23693085 DOI: 10.1017/s0007114513001566] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
In the present study, the effect of long-term fructose feeding on skeletal muscle mitochondrial energetics was investigated. Measurements in isolated tissue were coupled with the determination of whole-body energy expenditure and insulin sensitivity. A significant increase in plasma NEFA, as well as in skeletal muscle TAG and ceramide, was found in fructose-fed rats compared with the controls, together with a significantly higher plasma insulin response to a glucose load, while no significant variation in plasma glucose levels was found. Significantly lower RMR values were found in fructose-fed rats starting from week 4 of the dietary treatment. Skeletal muscle mitochondrial mass and degree of coupling were found to be significantly higher in fructose-fed rats compared with the controls. Significantly higher lipid peroxidation was found in fructose-fed rats, together with a significant decrease in superoxide dismutase activity. Phosphorylated Akt levels normalised to plasma insulin levels were significantly lower in fructose-fed rats compared with the controls. In conclusion, a fructose-rich diet has a deep impact on a metabolically relevant tissue such as skeletal muscle. In this tissue, the consequences of high fructose feeding are altered glucose tolerance, elevated mitochondrial biogenesis and increased mitochondrial coupling. This latter modification could have a detrimental metabolic effect by causing oxidative stress and energy sparing that contribute to the high metabolic efficiency of fructose-fed rats.
Collapse
|
99
|
Abstract
Based on evidence that patients with type 2 diabetes (T2DM), obese insulin-resistant individuals, and lean insulin-resistant offspring of parents with T2DM have ~30% less mitochondria in their muscles than lean control subjects, it appears to be widely accepted that mitochondrial "deficiency" is responsible for insulin resistance. The proposed mechanism for this effect is an impaired ability to oxidize fat, resulting in lipid accumulation in muscle. The purpose of this counterpoint article is to review the evidence against the mitochondrial deficiency concept. This evidence includes the findings that 1) development of insulin resistance in laboratory rodents fed high-fat diets occurs despite a concomitant increase in muscle mitochondria; 2) mitochondrial deficiency severe enough to impair fat oxidation in resting muscle causes an increase, not a decrease, in insulin action; and 3) most of the studies comparing fat oxidation in insulin-sensitive and insulin-resistant individuals have shown that fat oxidation is higher in T2DM patients and obese insulin-resistant individuals than in insulin-sensitive control subjects. In conclusion, it seems clear, based on this evidence, that the 30% reduction in muscle content of mitochondria in patients with T2DM is not responsible for insulin resistance.
Collapse
Affiliation(s)
- John O Holloszy
- Division of Geriatrics and Nutritional Sciences, Department of Medicine, Washington University School of Medicine, St Louis, Missouri, USA.
| |
Collapse
|
100
|
Badin PM, Vila IK, Louche K, Mairal A, Marques MA, Bourlier V, Tavernier G, Langin D, Moro C. High-fat diet-mediated lipotoxicity and insulin resistance is related to impaired lipase expression in mouse skeletal muscle. Endocrinology 2013; 154:1444-53. [PMID: 23471217 DOI: 10.1210/en.2012-2029] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Elevated expression/activity of adipose triglyceride lipase (ATGL) and/or reduced activity of hormone-sensitive lipase (HSL) in skeletal muscle are causally linked to insulin resistance in vitro. We investigated here the effect of high-fat feeding on skeletal muscle lipolytic proteins, lipotoxicity, and insulin signaling in vivo. Five-week-old C3H mice were fed normal chow diet (NCD) or 45% kcal high-fat diet (HFD) for 4 weeks. Wild-type and HSL knockout mice fed NCD were also studied. Whole-body and muscle insulin sensitivity, as well as lipolytic protein expression, lipid levels, and insulin signaling in skeletal muscle, were measured. HFD induced whole-body insulin resistance and glucose intolerance and reduced skeletal muscle glucose uptake compared with NCD. HFD increased skeletal muscle total diacylglycerol (DAG) content, protein kinase Cθ and protein kinase Cε membrane translocation, and impaired insulin signaling as reflected by a robust increase of basal Ser1101 insulin receptor substrate 1 phosphorylation (2.8-fold, P < .05) and a decrease of insulin-stimulated v-Akt murine thymoma viral oncogene homolog Ser473 (-37%, P < .05) and AS160 Thr642 (-47%, P <.01) phosphorylation. We next showed that HFD strongly reduced HSL phosphorylation at Ser660. HFD significantly up-regulated the muscle protein content of the ATGL coactivator comparative gene identification 58 and triacylglycerol hydrolase activity, despite a lower ATGL protein content. We further show a defective skeletal muscle insulin signaling and DAG accumulation in HSL knockout compared with wild-type mice. Together, these data suggest a pathophysiological link between altered skeletal muscle lipase expression and DAG-mediated insulin resistance in mice.
Collapse
Affiliation(s)
- Pierre-Marie Badin
- Institut National de la Santé et de la Recherche Médicale, Unité Mixte de Recherche 1048, Obesity Research Laboratory, Institute of Metabolic and Cardiovascular Diseases, 31432 Toulouse Cedex 4, France
| | | | | | | | | | | | | | | | | |
Collapse
|