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Katsanos CS, Tran L, Hoffman N, Roust LR, De Filippis EA, Mandarino LJ, Johnsson K, Belohlavek M, Buras MR. Impaired Suppression of Plasma Lipid Extraction and its Partitioning Away from Muscle by Insulin in Humans with Obesity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.11.598550. [PMID: 38915696 PMCID: PMC11195248 DOI: 10.1101/2024.06.11.598550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/26/2024]
Abstract
Context Humans with obesity and insulin resistance exhibit lipid accumulation in skeletal muscle, but the underlying biological mechanisms responsible for the accumulation of lipid in the muscle of these individuals remain unknown. Objective We investigated how plasma insulin modulates the extraction of circulating triglycerides (TGs) and non-esterified fatty acids (NEFAs) from dietary and endogenous sources in the muscle of lean, insulin-sensitive humans (Lean-IS) and contrasted these responses to those in humans with obesity and insulin resistance (Obese-IR). Methods The studies were performed in a postprandial state associated with steady-state plasma TG concentrations. The arterio-venous blood sampling technique was employed to determine the extraction of circulating lipids across the forearm muscle before and after insulin infusion. We distinguished kinetics of TGs and NEFAs from dietary sources across muscle from those from endogenous sources by incorporating stable isotope-labeled triolein in ingested fat. Results Plasma insulin rapidly suppressed the extraction of plasma TGs from endogenous, but not dietary, sources in the Lean-IS, but same response was absent in the Obese-IR. Furthermore, in the muscle of Lean-IS, plasma insulin decreased the extraction of circulating NEFAs from both dietary and endogenous sources, but in Obese-IR subjects this response was absent for NEFAs from dietary sources. Conclusions Partitioning of circulating lipids away from the skeletal muscle when plasma insulin increases, such as during the postprandial period, is impaired in humans with obesity and insulin resistance. Trial Registration: ClinicalTrials.gov ( NCT01860911 ).
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Carrard J, Hofer M, Prechtl L, Fleischlin E, Huber M, Gallart-Ayala H, Teav T, Infanger D, Höchsmann C, Koehler K, Hinrichs T, Hanssen H, Ivanisevic J, Schmidt-Trucksäss A. Effect of an eight-week high-intensity interval training programme on circulating sphingolipid levels in middle-aged adults at elevated cardiometabolic risk (SphingoFIT)-Protocol for a randomised controlled exercise trial. PLoS One 2024; 19:e0302477. [PMID: 38717997 PMCID: PMC11078397 DOI: 10.1371/journal.pone.0302477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2024] [Accepted: 04/03/2024] [Indexed: 05/12/2024] Open
Abstract
INTRODUCTION Evidence indicates that sphingolipid accumulation drives complex molecular alterations promoting cardiometabolic diseases. Clinically, it was shown that sphingolipids predict cardiometabolic risk independently of and beyond traditional biomarkers such as low-density lipoprotein cholesterol. To date, little is known about therapeutic modalities to lower sphingolipid levels. Exercise, a powerful means to prevent and treat cardiometabolic diseases, is a promising modality to mitigate sphingolipid levels in a cost-effective, safe, and patient-empowering manner. METHODS This randomised controlled trial will explore whether and to what extent an 8-week fitness-enhancing training programme can lower serum sphingolipid levels of middle-aged adults at elevated cardiometabolic risk (n = 98, 50% females). The exercise intervention will consist of supervised high-intensity interval training (three sessions weekly), while the control group will receive physical activity counselling based on current guidelines. Blood will be sampled early in the morning in a fasted state before and after the 8-week programme. Participants will be provided with individualised, pre-packaged meals for the two days preceding blood sampling to minimise potential confounding. An 'omic-scale sphingolipid profiling, using high-coverage reversed-phase liquid chromatography coupled to tandem mass spectrometry, will be applied to capture the circulating sphingolipidome. Maximal cardiopulmonary exercise tests will be performed before and after the 8-week programme to assess patient fitness changes. Cholesterol, triglycerides, glycated haemoglobin, the homeostatic model assessment for insulin resistance, static retinal vessel analysis, flow-mediated dilatation, and strain analysis of the heart cavities will also be assessed pre- and post-intervention. This study shall inform whether and to what extent exercise can be used as an evidence-based treatment to lower circulating sphingolipid levels. TRIAL REGISTRATION The trial was registered on www.clinicaltrials.gov (NCT06024291) on August 28, 2023.
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Affiliation(s)
- Justin Carrard
- Division of Sport and Exercise Medicine, Department of Sport, Exercise and Health, University of Basel, Basel, Switzerland
- SportAdo Centre, Children and Adolescent Surgery, Woman-Mother-Child Department, Lausanne University Hospital, Lausanne, Switzerland
| | - Manuel Hofer
- Division of Sport and Exercise Medicine, Department of Sport, Exercise and Health, University of Basel, Basel, Switzerland
| | - Luisa Prechtl
- Division of Sport and Exercise Medicine, Department of Sport, Exercise and Health, University of Basel, Basel, Switzerland
| | - Eva Fleischlin
- Division of Sport and Exercise Medicine, Department of Sport, Exercise and Health, University of Basel, Basel, Switzerland
| | - Manuel Huber
- Division of Sport and Exercise Medicine, Department of Sport, Exercise and Health, University of Basel, Basel, Switzerland
| | - Hector Gallart-Ayala
- Metabolomics Platform, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Tony Teav
- Metabolomics Platform, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Denis Infanger
- Division of Sport and Exercise Medicine, Department of Sport, Exercise and Health, University of Basel, Basel, Switzerland
| | - Christoph Höchsmann
- Department of Health and Sport Sciences, TUM School of Medicine and Health, Technical University of Munich, Munich, Germany
| | - Karsten Koehler
- Department of Health and Sport Sciences, TUM School of Medicine and Health, Technical University of Munich, Munich, Germany
| | - Timo Hinrichs
- Division of Sport and Exercise Medicine, Department of Sport, Exercise and Health, University of Basel, Basel, Switzerland
| | - Henner Hanssen
- Division of Sport and Exercise Medicine, Department of Sport, Exercise and Health, University of Basel, Basel, Switzerland
| | - Julijana Ivanisevic
- Metabolomics Platform, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Arno Schmidt-Trucksäss
- Division of Sport and Exercise Medicine, Department of Sport, Exercise and Health, University of Basel, Basel, Switzerland
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Barrett JS, Whytock KL, Strauss JA, Wagenmakers AJM, Shepherd SO. High intramuscular triglyceride turnover rates and the link to insulin sensitivity: influence of obesity, type 2 diabetes and physical activity. Appl Physiol Nutr Metab 2022; 47:343-356. [PMID: 35061523 DOI: 10.1139/apnm-2021-0631] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Large intramuscular triglyceride (IMTG) stores in sedentary, obese individuals have been linked to insulin resistance, yet well-trained athletes exhibit high IMTG levels whilst maintaining insulin sensitivity. Contrary to previous assumptions, it is now known that IMTG content per se does not result in insulin resistance. Rather, insulin resistance is caused, at least in part, by the presence of high concentrations of harmful lipid metabolites, such as diacylglycerols and ceramides in muscle. Several mechanistic differences between obese sedentary individuals and their highly trained counterparts have been identified, which determine the differential capacity for IMTG synthesis and breakdown in these populations. In this review, we first describe the most up-to-date mechanisms by which a low IMTG turnover rate (both breakdown and synthesis) leads to the accumulation of lipid metabolites and results in skeletal muscle insulin resistance. We then explore current and potential exercise and nutritional strategies that target IMTG turnover in sedentary obese individuals, to improve insulin sensitivity. Overall, improving IMTG turnover should be an important component of successful interventions that aim to prevent the development of insulin resistance in the ever-expanding sedentary, overweight and obese populations. Novelty: A description of the most up-to-date mechanisms regulating turnover of the IMTG pool. An exploration of current and potential exercise/nutritional strategies to target and enhance IMTG turnover in obese individuals. Overall, highlights the importance of improving IMTG turnover to prevent the development of insulin resistance.
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Affiliation(s)
- J S Barrett
- Research Institute for Sport & Exercise Sciences, Liverpool John Moores University, Liverpool, UK
| | - K L Whytock
- Translational Research Institute, AdventHealth, Orlando, FL 32804, USA
| | - J A Strauss
- Research Institute for Sport & Exercise Sciences, Liverpool John Moores University, Liverpool, UK
| | - A J M Wagenmakers
- Research Institute for Sport & Exercise Sciences, Liverpool John Moores University, Liverpool, UK
| | - S O Shepherd
- Research Institute for Sport & Exercise Sciences, Liverpool John Moores University, Liverpool, UK
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Li LJ, Ma J, Li SB, Chen XF, Zhang J. Electric pulse stimulation inhibited lipid accumulation on C2C12 myotubes incubated with oleic acid and palmitic acid. Arch Physiol Biochem 2021; 127:344-350. [PMID: 31298959 DOI: 10.1080/13813455.2019.1639763] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
OBJECTIVE To investigate the effect of electrical pulse stimulation (EPS) on lipid accumulation and alteration of fatty acid-related enzymes in C2C12 myotubes incubated with fatty acids. METHODS Mouse C2C12 myotubes were incubated with oleic acid and palmitic acid, and differentiated C2C12 myotubes were treated with EPS, oil-red O (ORO), BODIPY staining and triglyceride (TG) content were examined. Total RNA was isolated, and real-time polymerase chain reaction analysis was performed. RESULTS (1) EPS decreased TG content (p < .01). (2) EPS significantly induced the mRNA expression of FAD/CD36 (p < .05), FATP4 (p < .001), FABP1 (p < .01) and FABP5 (p < .01). (3) EPS significantly inhibited the mRNA expression of fatty acid synthase (p < .01). (4) Adipose triglyceride lipase and hormone-sensitive lipase expression were significantly elevated (p < .001), and induced the mRNA expression of CPT1 (p < .01), ACOX1 (p < .05), UCP3 (p < .05) and PPARα (p < .001) after EPS. CONCLUSION EPS reduced lipid droplet accumulation; enhanced CD36, FATP4, FABP1 and FABP5 expression; inhibited C2C12 myotube fatty acid re-esterification; and promoted fatty acid oxidation in C2C12 myotubes.
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Affiliation(s)
- Ling-Jie Li
- College of P.E. and Sports, Beijing Normal University, Beijing, China
| | - Jin Ma
- College of P.E. and Sports, Beijing Normal University, Beijing, China
| | - Song-Bo Li
- China Academy of Sport and Health Science, Beijing Sport University, Beijing, China
| | - Xue-Fei Chen
- College of P.E. and Sports, Beijing Normal University, Beijing, China
| | - Jing Zhang
- College of P.E. and Sports, Beijing Normal University, Beijing, China
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BMP11 Negatively Regulates Lipid Metabolism in C2C12 Muscle Cells. BIOTECHNOL BIOPROC E 2020. [DOI: 10.1007/s12257-020-0254-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Tan-Chen S, Guitton J, Bourron O, Le Stunff H, Hajduch E. Sphingolipid Metabolism and Signaling in Skeletal Muscle: From Physiology to Physiopathology. Front Endocrinol (Lausanne) 2020; 11:491. [PMID: 32849282 PMCID: PMC7426366 DOI: 10.3389/fendo.2020.00491] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 06/22/2020] [Indexed: 12/14/2022] Open
Abstract
Sphingolipids represent one of the major classes of eukaryotic lipids. They play an essential structural role, especially in cell membranes where they also possess signaling properties and are capable of modulating multiple cell functions, such as apoptosis, cell proliferation, differentiation, and inflammation. Many sphingolipid derivatives, such as ceramide, sphingosine-1-phosphate, and ganglioside, have been shown to play many crucial roles in muscle under physiological and pathological conditions. This review will summarize our knowledge of sphingolipids and their effects on muscle fate, highlighting the role of this class of lipids in modulating muscle cell differentiation, regeneration, aging, response to insulin, and contraction. We show that modulating sphingolipid metabolism may be a novel and interesting way for preventing and/or treating several muscle-related diseases.
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Affiliation(s)
- Sophie Tan-Chen
- Centre de Recherche des Cordeliers, INSERM, Sorbonne Université, Université de Paris, Paris, France
- Institut Hospitalo-Universitaire ICAN, Paris, France
| | - Jeanne Guitton
- Université Saclay, CNRS UMR 9197, Institut des Neurosciences Paris-Saclay, Orsay, France
| | - Olivier Bourron
- Centre de Recherche des Cordeliers, INSERM, Sorbonne Université, Université de Paris, Paris, France
- Institut Hospitalo-Universitaire ICAN, Paris, France
- Assistance Publique-Hôpitaux de Paris, Département de Diabétologie et Maladies Métaboliques, Hôpital Pitié-Salpêtrière, Paris, France
| | - Hervé Le Stunff
- Université Saclay, CNRS UMR 9197, Institut des Neurosciences Paris-Saclay, Orsay, France
| | - Eric Hajduch
- Centre de Recherche des Cordeliers, INSERM, Sorbonne Université, Université de Paris, Paris, France
- Institut Hospitalo-Universitaire ICAN, Paris, France
- *Correspondence: Eric Hajduch
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Loher H, Jenni S, Bucher J, Krüsi M, Kreis R, Boesch C, Christ E. Impaired repletion of intramyocellular lipids in patients with growth hormone deficiency after a bout of aerobic exercise. Growth Horm IGF Res 2018; 42-43:32-39. [PMID: 30153529 DOI: 10.1016/j.ghir.2018.08.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 08/04/2018] [Accepted: 08/12/2018] [Indexed: 01/04/2023]
Abstract
BACKGROUND Ectopic lipids such as intramyocellular lipids (IMCL) are depleted by exercise and repleted by diet, whereas intrahepatocellular lipids (IHCL) are increased immediately after exercise. So far, it is unclear how ectopic lipids behave 24 h after exercise and whether the lack of growth hormone (GH) significantly affects ectopic lipids 24 h after exercise. METHODS Seven male patients with growth hormone deficiency (GHD) and seven sedentary male control subjects (CS) were included. VO2max was assessed by spiroergometry; visceral and subcutaneous fat by whole body MRI. 1H-MR-spectroscopy was performed in M. vastus intermedius and in the liver before and after 2 h of exercise at 50% VO2max and 24 h thereafter, while diet and physical activity were standardized. RESULTS Sedentary male subjects (7 GHD, 7 CS) were recruited. Age, BMI, waist circumference, visceral and subcutaneous fat mass was not significantly different between GHD and CS. VO2max was significantly lower in GHD vs. CS. IMCL were diminished through aerobic exercise in both groups: (-11.5 ± 21.9% in CS; -8.9% ±19.1% in GHD) and restored after 24 h in CS (-5.5 ± 26.6% compared to baseline) but not in GHD (-17.9 ± 15.3%). IHCL increased immediately after exercise and decreased to baseline within 24 h. CONCLUSION These findings suggest that GHD may affect repletion of IMCL 24 h after aerobic exercise.
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Affiliation(s)
- Hannah Loher
- Division of Diabetology, Endocrinology, Clinical Nutrition and Metabolism, Inselspital, Bern University Hospital, University of Bern, Switzerland; Department of Medicine, Cantonal Hospital St. Gallen, St. Gallen, Switzerland
| | - Stefan Jenni
- Division of Diabetology, Endocrinology, Clinical Nutrition and Metabolism, Inselspital, Bern University Hospital, University of Bern, Switzerland; EndoDia Praxis, Biel, Switzerland
| | - Julie Bucher
- Division of Diabetology, Endocrinology, Clinical Nutrition and Metabolism, Inselspital, Bern University Hospital, University of Bern, Switzerland; EndoDia Praxis, Biel, Switzerland
| | - Marion Krüsi
- Division of Diabetology, Endocrinology, Clinical Nutrition and Metabolism, Inselspital, Bern University Hospital, University of Bern, Switzerland
| | - Roland Kreis
- Department of Biomedical Research & Institute of Interventional, Diagnostic and Pediatric Radiology, University of Bern, Bern, Switzerland
| | - Chris Boesch
- Department of Biomedical Research & Institute of Interventional, Diagnostic and Pediatric Radiology, University of Bern, Bern, Switzerland
| | - Emanuel Christ
- Division of Diabetology, Endocrinology, Clinical Nutrition and Metabolism, Inselspital, Bern University Hospital, University of Bern, Switzerland; Division of Endocrinology, Diabetology and Metabolism, University Hospital of Basel, Basel, Switzerland.
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Honkala SM, Motiani KK, Eskelinen JJ, Savolainen A, Saunavaara V, Virtanen KA, Löyttyniemi E, Kapanen J, Knuuti J, Kalliokoski KK, Hannukainen JC. Exercise Training Reduces Intrathoracic Fat Regardless of Defective Glucose Tolerance. Med Sci Sports Exerc 2017. [PMID: 28628064 PMCID: PMC5473372 DOI: 10.1249/mss.0000000000001232] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Purpose Epicardial (EAT) and pericardial (PAT) fat masses and myocardial triglyceride content (MTC) are enlarged in obesity and insulin resistance. We studied whether the high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) similarly decrease ectopic fat in and around the heart and whether the decrease is similar in healthy subjects and subjects with defective glucose tolerance (DGT). Methods A total of 28 healthy men (body mass index = 20.7–30.0 kg·m−2, age = 40–55 yr) and 16 men with DGT (body mass index = 23.8–33.5 kg·m−2, age = 43–53 yr) were randomized into HIIT and MICT interventions for 2 wk. EAT and PAT were determined by computed tomography and MTC by 1H-MRS. Results At baseline, DGT subjects had impaired aerobic capacity and insulin sensitivity and higher levels of whole body fat, visceral fat, PAT, and EAT (P < 0.05, all) compared with healthy subjects. In the whole group, HIIT increased aerobic capacity (HIIT = 6%, MICT = 0.3%; time × training P = 0.007) and tended to improve insulin sensitivity (HIIT = 24%, MICT = 8%) as well as reduce MTC (HIIT = −42%, MICT = +23%) (time × training P = 0.06, both) more efficiently compared with MICT, and without differences in the training response between the healthy and the DGT subjects. However, both training modes decreased EAT (−5%) and PAT (−6%) fat (time P < 0.05) and not differently between the healthy and the DGT subjects. Conclusion Whole body fat, visceral fat, PAT, and EAT masses are enlarged in DGT. Both HIIT and MICT effectively reduce EAT and PAT in healthy and DGT subjects, whereas HIIT seems to be superior as regards improving aerobic capacity, whole-body insulin sensitivity, and MTC.
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Affiliation(s)
- Sanna M Honkala
- 1Turku PET Centre, University of Turku, Turku, FINLAND; 2Turku PET Centre, Turku University Hospital, Turku, FINLAND; 3Department of Medical Physics, Turku University Hospital, Turku, FINLAND; 4Department of Biostatistics, University of Turku, Turku, FINLAND; and 5Paavo Nurmi Centre, University of Turku, Turku, FINLAND
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Baik M, Kang HJ, Park SJ, Na SW, Piao M, Kim SY, Fassah DM, Moon YS. TRIENNIAL GROWTH AND DEVELOPMENT SYMPOSIUM: Molecular mechanisms related to bovine intramuscular fat deposition in the longissimus muscle. J Anim Sci 2017; 95:2284-2303. [PMID: 28727015 DOI: 10.2527/jas.2016.1160] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
The intramuscular fat (IMF) content of the LM, also known as marbling, is particularly important in determining the price of beef in Korea, Japan, and the United States. Deposition of IMF is influenced by both genetic (e.g., breed, gender, and genotype) and nongenetic factors (e.g., castration, nutrition, stressors, animal weight, and age). Castration of bulls markedly increases deposition of IMF, resulting in improved beef quality. Here, we present a comparative gene expression approach between bulls and steers. Transcriptomic and proteomic studies have demonstrated that the combined effects of increases in lipogenesis, fatty acid uptake, and fatty acid esterification and decreased lipolysis are associated with increased IMF deposition in the LM. Several peripheral tissues (LM, adipose tissues, and the liver) are involved in lipid metabolism. Therefore, understanding the significance of the tissue network in lipid metabolism is important. Here, we demonstrate that lipid metabolism in LM tissues is crucial for IMF deposition, whereas lipid metabolism in the liver plays only a minor role. Metabolism of body fat and IMF deposition in bovine species has similarities with these processes in metabolic diseases, such as obesity in humans and rodents. Extensive studies on metabolic diseases using epigenome modification (DNA methylation, histone modification, and microRNA), microbial metagenomics, and metabolomics have been performed in humans and rodents, and new findings have been reported using these technologies. The importance of applying "omics" fields (epigenomics, metagenomics, and metabolomics) to the study of IMF deposition in cattle is described. New information on the molecular mechanisms of IMF deposition may be used to design nutritional or genetic methods to manipulate IMF deposition and to modify fatty acid composition in beef cattle. Applying nutrigenomics could maximize the expression of genetic potential of economically important traits (e.g., marbling) in animals.
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Gemmink A, Goodpaster BH, Schrauwen P, Hesselink MKC. Intramyocellular lipid droplets and insulin sensitivity, the human perspective. Biochim Biophys Acta Mol Cell Biol Lipids 2017; 1862:1242-1249. [PMID: 28739280 DOI: 10.1016/j.bbalip.2017.07.010] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Revised: 07/18/2017] [Accepted: 07/19/2017] [Indexed: 11/19/2022]
Abstract
Skeletal muscle can store excess fat as subcellular lipid droplets (LDs). While originally viewed as uninteresting static balls of triacylglycerol, it is now clear that myocellular LDs play an active role in myocellular (patho)physiology. In this review we aim to discuss the role of LDs in muscle cell insulin sensitivity and identify parameters which appear to affect this relationship. Moreover, we discuss the application of novel tools permitting detailed examination of these parameters. This article is part of a Special Issue entitled: Recent Advances in Lipid Droplet Biology edited by Rosalind Coleman and Matthijs Hesselink.
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Affiliation(s)
- Anne Gemmink
- Department of Human Biology and Human Movement Sciences, NUTRIM School for Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, 6200MD Maastricht, The Netherlands
| | - Bret H Goodpaster
- Translational Research Institute for Metabolism and Diabetes, Orlando, FL, USA
| | - Patrick Schrauwen
- Department of Human Biology and Human Movement Sciences, NUTRIM School for Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, 6200MD Maastricht, The Netherlands
| | - Matthijs K C Hesselink
- Department of Human Biology and Human Movement Sciences, NUTRIM School for Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, 6200MD Maastricht, The Netherlands.
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Delgado Cuenca P, Almaiman L, Schenk S, Kern M, Hooshmand S. Dried Plum Ingestion Increases the Osteoblastogenic Capacity of Human Serum. J Med Food 2017; 20:653-658. [PMID: 28445075 DOI: 10.1089/jmf.2016.0158] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
In cell culture studies, dried plum (Prunus domestica L.) polyphenols increased osteoblast alkaline phosphatase (ALP) activity, mineralized nodule formation, and the expression of the bone marker genes runt-related transcription factor 2 (RUNX2) and osterix. The purpose of this study was to determine whether human serum collected 1 and 2 h after dried plum ingestion influenced osteoblast cell activity and gene expression. Five healthy women ingested 100 g of dried plum, and serum samples were collected at baseline (before dried plum ingestion) and 1 and 2 h postingestion of dried plum. MC3T3-E1 osteoblast cells were treated (2% of medium) with these serum samples for 3 or 9 days. Intracellular and extracellular ALP activities were significantly increased after 3 or 9 days of treatment with serum both postingestion time points, with no effect seen in baseline samples. Also, serum obtained 1 and 2 h postingestion significantly increased the mRNA expression of bone markers RUNX2 and connexin43 (CX43) after both 3 and 9 days of incubation periods. Finally, serum obtained 1 and 2 h postingestion increased the mRNA expression of β-catenin after 9 days of incubation. We conclude that osteoblast activity and function are increased by dried plum ingestion, which may, in part, explain its beneficial effects on bone health.
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Affiliation(s)
- Paulina Delgado Cuenca
- 1 School of Exercise and Nutritional Sciences, San Diego State University , San Diego, California, USA
| | - Lama Almaiman
- 1 School of Exercise and Nutritional Sciences, San Diego State University , San Diego, California, USA
| | - Simon Schenk
- 2 Department of Orthopedic Surgery, University of California San Diego , La Jolla, California, USA
| | - Mark Kern
- 1 School of Exercise and Nutritional Sciences, San Diego State University , San Diego, California, USA
| | - Shirin Hooshmand
- 1 School of Exercise and Nutritional Sciences, San Diego State University , San Diego, California, USA
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Long-term treatment with nicotinamide induces glucose intolerance and skeletal muscle lipotoxicity in normal chow-fed mice: compared to diet-induced obesity. J Nutr Biochem 2016; 36:31-41. [PMID: 27567590 DOI: 10.1016/j.jnutbio.2016.07.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Revised: 05/06/2016] [Accepted: 07/05/2016] [Indexed: 12/11/2022]
Abstract
Nicotinamide (NAM), or vitamin B3, is an essential coenzyme for ATP synthesis and an inhibitor of sirtuin 1. Recently, conflicting results were reported regarding the treatment of NAM in type 2 diabetes and obesity. The aim of this study was to determine whether and how long-term treatment with NAM at lower dose would affect insulin sensitivity in mice fed chow diet. We treated mice with NAM (100 mg/kg/day) and normal chow for 8 weeks. Strikingly, NAM induced glucose intolerance and skeletal muscle lipid accumulation in nonobese mice. NAM impaired mitochondrial respiration capacity and energy production in skeletal muscle, in combination with increased expression of the mediators for mitophagy (p62, PINK1, PARK2 and NIX) and autophagy (FOXO3, Bnip3, CTSL, Beclin1 and LC-3b). Next, we treated mice with high-fat diet (HFD) and resveratrol (RSV; 100 mg/kg/day) for 8 weeks. RSV protected against HFD-induced insulin resistance and obesity. HFD increased skeletal muscle lipid content as well as NAM, but this increase was attenuated by RSV. In contrast to NAM, HFD enhanced fatty acid oxidative capacity. Muscle transcript levels of genes for mitophagy and autophagy were largely suppressed by HFD, whereas RSV did not rescue these effects. These differences suggest that skeletal muscle autophagy may represent adaptive response to NAM-induced lipotoxicity, whereas reduced autophagy in skeletal muscle may promote HFD-induced lipotoxicity. Our results demonstrate that chronic NAM supplementation in healthy individuals, although at lower dose than previously reported, is still detrimental to glucose homeostasis and skeletal muscle lipid metabolism.
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Jayewardene AF, Mavros Y, Reeves A, Hancock DP, Gwinn T, Rooney KB. Interactions Between Fatty Acid Transport Proteins, Genes That Encode for Them, and Exercise: A Systematic Review. J Cell Physiol 2016; 231:1671-87. [PMID: 26638980 DOI: 10.1002/jcp.25281] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Accepted: 12/04/2015] [Indexed: 01/29/2023]
Abstract
Long-chain fatty acid (LCFA) movement into skeletal muscle involves a highly mediated process in which lipid rafts are utilized in the cellular membrane, involving numerous putative plasma membrane-associated LCFA transport proteins. The process of LCFA uptake and oxidation is of particular metabolic significance both at rest and during light to moderate exercise. A comprehensive systematic search of electronic databases was conducted to investigate whether exercise alters protein and/or gene expression of putative LCFA transport proteins. There were 31 studies meeting all eligibility criteria, of these 13 utilized an acute exercise protocol and 18 examined chronic exercise adaptations. Seventeen involved a study design incorporating an exercise stimulus, while the remaining 14 incorporated a combined exercise and diet stimulus. Divergent data relating to acute exercise, as well as prolonged exercise training (≥3 weeks), on protein content (PC) response was identified for proteins CD36, FABPpm and CAV1. Messenger ribonucleic acid (mRNA) data did not always correspond to functional PC, supporting previous suggestions of a disconnect due to potentially limiting factors post gene expression. The large array of study designs, cohorts, and primary dependent variables within the studies included in the present review elucidate the complexity of the interaction between exercise and LCFA transport proteins. Summary of the results in the present review validate the need for further targeted investigation within this topic, and provide an important information base for such research. J. Cell. Physiol. 231: 1671-1687, 2016. © 2015 Wiley Periodicals, Inc.
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Affiliation(s)
- Avindra F Jayewardene
- Discipline of Exercise and Sport Science, Faculty of Health Sciences, University of Sydney, Lidcombe, New South Wales, Australia
| | - Yorgi Mavros
- Discipline of Exercise and Sport Science, Faculty of Health Sciences, University of Sydney, Lidcombe, New South Wales, Australia
| | - Anneliese Reeves
- Discipline of Exercise and Sport Science, Faculty of Health Sciences, University of Sydney, Lidcombe, New South Wales, Australia
| | - Dale P Hancock
- School of Molecular Biosciences, Faculty of Science, University of Sydney, Camperdown, New South Wales, Australia
| | - Tom Gwinn
- Discipline of Exercise and Sport Science, Faculty of Health Sciences, University of Sydney, Lidcombe, New South Wales, Australia
| | - Kieron B Rooney
- Discipline of Exercise and Sport Science, Faculty of Health Sciences, University of Sydney, Lidcombe, New South Wales, Australia
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Vigelsø A, Gram M, Wiuff C, Hansen CN, Prats C, Dela F, Helge JW. Effects of immobilization and aerobic training on proteins related to intramuscular substrate storage and metabolism in young and older men. Eur J Appl Physiol 2015; 116:481-94. [DOI: 10.1007/s00421-015-3302-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Accepted: 11/16/2015] [Indexed: 12/12/2022]
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15
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Newsom SA, Everett AC, Park S, Van Pelt DW, Hinko A, Horowitz JF. Lipid mixtures containing a very high proportion of saturated fatty acids only modestly impair insulin signaling in cultured muscle cells. PLoS One 2015; 10:e0120871. [PMID: 25793412 PMCID: PMC4368748 DOI: 10.1371/journal.pone.0120871] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Accepted: 02/07/2015] [Indexed: 11/24/2022] Open
Abstract
In vitro examinations of the effect of saturated fatty acids on skeletal muscle insulin action often use only one or two different fatty acid species, which does not resemble the human plasma fatty acid profile. We compared graded concentrations (0.1-0.8 mM) of 3 different lipid mixtures: 1) a physiologic fatty acid mixture (NORM; 40% saturated fatty acids), 2) a physiologic mixture high in saturated fatty acids (HSFA; 60% saturated fatty acids), and 3) 100% palmitate (PALM) on insulin signaling and fatty acid partitioning into triacylglycerol (TAG) and diacylglycerol (DAG) in cultured muscle cells. As expected, PALM readily impaired insulin-stimulated pAktThr308/Akt and markedly increased intracellular DAG content. In contrast, the fatty acid mixtures only modestly impaired insulin-stimulated pAktThr308M/Akt, and we found no differences between NORM and HSFA. Importantly, NORM and HSFA did not increase DAG content, but instead dose-dependently increased TAG accumulation. Therefore, the robust impairment in insulin signaling found with palmitate exposure was attenuated with physiologic mixtures of fatty acids, even with a very high proportion of saturated fatty acids. This may be explained in part by selective partitioning of fatty acids into neutral lipid (i.e., TAG) when muscle cells were exposed to physiologic lipid mixtures.
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Affiliation(s)
- Sean A. Newsom
- Substrate Metabolism Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Allison C. Everett
- Substrate Metabolism Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Sanghee Park
- Substrate Metabolism Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Douglas W. Van Pelt
- Substrate Metabolism Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Alexander Hinko
- Substrate Metabolism Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Jeffrey F. Horowitz
- Substrate Metabolism Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, Michigan, United States of America
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16
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Badin PM, Langin D, Moro C. Dynamics of skeletal muscle lipid pools. Trends Endocrinol Metab 2013; 24:607-15. [PMID: 23988586 DOI: 10.1016/j.tem.2013.08.001] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2013] [Revised: 07/22/2013] [Accepted: 08/03/2013] [Indexed: 11/20/2022]
Abstract
Intramyocellular triacylglycerol (IMTG) is emerging as an important energy fuel source during muscle contraction and are adaptively increased in response to exercise, without adverse physiological effects. Paradoxically, elevated IMTG content in obese and type 2 diabetics has been linked to insulin resistance, highlighting the importance of IMTG pools in physiology and pathology. Two separate views suggest that IMTG dynamics are determinant for skeletal muscle fat oxidation, and that disruption of IMTG dynamics facilitates the accumulation of lipotoxic intermediates such as diacylglycerols and ceramides that interfere with insulin signaling. Thus, understanding the factors that control IMTG dynamics is crucial. Here we discuss recent literature describing the regulation of IMTG pools with a particular emphasis on lipases and lipid droplet (LD)-associated proteins.
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Affiliation(s)
- Pierre-Marie Badin
- Obesity Research Laboratory, Institut National de la Santé et de la Recherche Médicale (INSERM) Unité Mixte de Recherche (UMR) 1048, Institute of Metabolic and Cardiovascular Diseases (I2MC), Toulouse, France; University of Toulouse, UMR1048, Paul Sabatier University, Toulouse, France
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Abstract
Age-related muscle loss impacts on whole-body metabolism and leads to frailty and sarcopenia, which are risk factors for fractures and mortality. Although nutrients are integral to muscle metabolism the relationship between nutrition and muscle loss has only been extensively investigated for protein and amino acids. The objective of the present paper is to describe other aspects of nutrition and their association with skeletal muscle mass. Mechanisms for muscle loss relate to imbalance in protein turnover with a number of anabolic pathways of which the mechanistic TOR pathway and the IGF-1–Akt–FoxO pathways are the most characterised. In terms of catabolism the ubiquitin proteasome system, apoptosis, autophagy, inflammation, oxidation and insulin resistance are among the major mechanisms proposed. The limited research associating vitamin D, alcohol, dietary acid–base load, dietary fat and anti-oxidant nutrients with age-related muscle loss is described. Vitamin D may be protective for muscle loss; a more alkalinogenic diet and diets higher in the anti-oxidant nutrients vitamin C and vitamin E may also prevent muscle loss. Although present recommendations for prevention of sarcopenia focus on protein, and to some extent on vitamin D, other aspects of the diet including fruits and vegetables should be considered. Clearly, more research into other aspects of nutrition and their role in prevention of muscle loss is required.
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18
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Association between myocardial triglyceride content and cardiac function in healthy subjects and endurance athletes. PLoS One 2013; 8:e61604. [PMID: 23613879 PMCID: PMC3628784 DOI: 10.1371/journal.pone.0061604] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2012] [Accepted: 03/11/2013] [Indexed: 11/19/2022] Open
Abstract
Ectopic fat accumulation plays important roles in various metabolic disorders and cardiovascular diseases. Recent studies reported that myocardial triglyceride (TG) content measured by proton magnetic resonance spectroscopy (1H-MRS) is associated with aging, diabetes mellitus, and cardiac dysfunction. However, myocardial TG content in athletes has not yet been investigated. We performed 1H-MRS and cardiac magnetic resonance imaging in 10 male endurance athletes and 15 healthy male controls. Serum markers and other clinical parameters including arterial stiffness were measured. Cardiopulmonary exercise testing was also performed. There were no significant differences in clinical characteristics including age, anthropometric parameters, blood test results, or arterial stiffness between the two groups. Peak oxygen uptakes, end–diastolic volume (EDV), end–systolic volume (ESV), left ventricular (LV) mass, peak ejection rates and peak filling rates were significantly higher in the athlete group than in the control group (all P<0.02). Myocardial TG content was significantly lower in the athlete group than in the control group (0.60±0.20 vs. 0.89±0.41%, P<0.05). Myocardial TG content was negatively correlated with EDV (r = −0.47), ESV (r = −0.64), LV mass (r = −0.44), and epicardial fat volume (r = 0.47) (all P<0.05). In conclusion, lower levels of myocardial TG content were observed in endurance athletes and were associated with morphological changes related to physiological LV alteration in athletes, suggesting that metabolic imaging for measurement of myocardial TG content by 1H-MRS may be a useful technique for noninvasively assessing the “athlete’s heart”.
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19
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Kimber NE, Cameron-Smith D, McGee SL, Hargreaves M. Skeletal muscle fat metabolism after exercise in humans: influence of fat availability. J Appl Physiol (1985) 2013; 114:1577-85. [PMID: 23519231 DOI: 10.1152/japplphysiol.00824.2012] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The mechanisms facilitating increased skeletal muscle fat oxidation following prolonged, strenuous exercise remain poorly defined. The aim of this study was to examine the influence of plasma free fatty acid (FFA) availability on intramuscular malonyl-CoA concentration and the regulation of whole-body fat metabolism during a 6-h postexercise recovery period. Eight endurance-trained men performed three trials, consisting of 1.5 h high-intensity and exhaustive exercise, followed by infusion of saline, saline + nicotinic acid (NA; low FFA), or Intralipid and heparin [high FFA (HFA)]. Muscle biopsies were obtained at the end of exercise (0 h) and at 3 and 6 h in recovery. Ingestion of NA suppressed the postexercise plasma FFA concentration throughout recovery (P < 0.01), except at 4 h. The alteration of the availability of plasma FFA during recovery induced a significant increase in whole-body fat oxidation during the 6-h period for HFA (52.2 ± 4.8 g) relative to NA (38.4 ± 3.1 g; P < 0.05); however, this response was unrelated to changes in skeletal muscle malonyl-CoA and acetyl-CoA carboxylase (ACC)β phosphorylation, suggesting mechanisms other than phosphorylation-mediated changes in ACC activity may have a role in regulating fat metabolism in human skeletal muscle during postexercise recovery. Despite marked changes in plasma FFA availability, no significant changes in intramuscular triglyceride concentrations were detected. These data suggest that the regulation of postexercise skeletal muscle fat oxidation in humans involves factors other than the 5'AMP-activated protein kinase-ACCβ-malonyl-CoA signaling pathway, although malonyl-CoA-mediated regulation cannot be excluded completely in the acute recovery period.
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Affiliation(s)
- Nicholas E Kimber
- Department of Applied Science and Allied Health, Christchurch Polytechnic Institute of Technology, Christchurch, New Zealand.
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20
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Jeon JY, Kim YB. Is perilipin critical in fat utilization during exercise? Metabolism 2012; 61:291-2. [PMID: 22209667 DOI: 10.1016/j.metabol.2011.11.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2011] [Accepted: 11/07/2011] [Indexed: 11/28/2022]
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21
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Jeong J, Kwon EG, Im SK, Seo KS, Baik M. Expression of fat deposition and fat removal genes is associated with intramuscular fat content in longissimus dorsi muscle of Korean cattle steers. J Anim Sci 2012; 90:2044-53. [PMID: 22266990 DOI: 10.2527/jas.2011-4753] [Citation(s) in RCA: 102] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Intramuscular fat (IMF) in cattle is an important component of traits that influence meat quality. We measured carcass characteristics and gene expression in Korean steers to clarify the molecular mechanism(s) underlying IMF deposition in LM tissue by determining the correlation between IMF content and gene expression abundance and by developing models to predict IMF content using gene expression abundance. The deposition of IMF is determined by a balance between fat deposition and fat removal in the LM. We measured mRNA abundance of lipid metabolic genes including lipogenesis [acetyl CoA carboxylase (ACC), fatty acid synthase (FASN)], fatty lipid uptake [lipoprotein lipase (LPL), fatty acid translocase (CD36), fatty acid transport protein 1 (FATP1)], fatty acid esterification [glycerol-3-phosphate acyltransferase 1 (GPAT1), acylglycerol phosphate acyltransferase 1 (AGPAT1), diacylglycerol acyltransferase 1 (DGAT1), DGAT2], lipolysis [adipose triglyceride lipase (ATGL), hormone-sensitive lipase (HSL), monoglyceride lipase (MGL)], and fatty acid oxidation [carnitine palmitoyl transferase 1B, very long-chain acyl-CoA dehydrogenase (VLCAD), medium-chain acyl-CoA dehydrogenase (MCAD)] in the LM. The mRNA abundance of the GPAT1 gene showed the greatest correlation (r = 0.74; P < 0.001) with IMF content among 9 fat deposition genes. The gene expression abundance of other fat deposition genes including ACC, FASN, LPL, CD36, FATP1, AGPAT1, DGAT1, and DGAT2 also exhibited significant positive correlations (P < 0.05) with IMF content in the LM. Conversely, ATGL mRNA abundance showed the greatest negative correlation (r = -0.68; P < 0.001) with IMF content in the LM among 6 fat removal genes. The expression of other fat removal genes including MGL, VLCAD, and MCAD showed significant negative correlations (P < 0.05) with IMF content. Our findings show that the combined effects of increases in lipogenesis, fatty acid uptake, fatty acid esterification, and of decreases in lipolysis and fatty acid oxidation contribute to increasing IMF deposition in Korean steers. The multiple regression analysis revealed that the mRNA abundance of the GPAT1 gene in the LM was the first major variable predicting IMF content (54%) among 15 lipid metabolic genes. The second was mRNA abundance of ATGL (11%). In conclusion, these results suggest that GPAT1 and ATGL genes could be used as genetic markers to predict IMF deposition in the LM.
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Affiliation(s)
- J Jeong
- Department of Molecular Biotechnology, Chonnam National University, Gwangju, Republic of Korea
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22
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Re-evaluating lipotoxic triggers in skeletal muscle: Relating intramyocellular lipid metabolism to insulin sensitivity. Prog Lipid Res 2012; 51:36-49. [DOI: 10.1016/j.plipres.2011.11.003] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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23
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Mai K, Andres J, Bobbert T, Assmann A, Biedasek K, Diederich S, Graham I, Larson TR, Pfeiffer AFH, Spranger J. Rosiglitazone increases fatty acid Δ9-desaturation and decreases elongase activity index in human skeletal muscle in vivo. Metabolism 2012; 61:108-16. [PMID: 21741058 DOI: 10.1016/j.metabol.2011.05.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2010] [Revised: 05/18/2011] [Accepted: 05/19/2011] [Indexed: 11/26/2022]
Abstract
The ratio of unsaturated to saturated long-chain fatty acids (LC-FAs) in skeletal muscle has been associated with insulin resistance. Some animal data suggest a modulatory effect of peroxisome proliferator receptor γ (PPARγ) stimulation on stearoyl-CoA desaturase 1 (SCD1) and LC-FA composition in skeletal muscle, but human data are rare. We here investigate whether treatment with a PPARγ agonist affects myocellular SCD1 expression and modulates the intramyocellular fatty acid profile in individuals with impaired glucose tolerance. Muscle biopsies and hyperinsulinemic-euglycemic clamps were performed in 7 men before and after 8 weeks of rosiglitazone treatment. Intramyocellular saturated, monounsaturated, and polyunsaturated intramuscular fatty acid profiles were measured by gas chromatography. Effects on SCD1 messenger RNA expression were analyzed in C2C12 cells and in human biopsies before and after rosiglitazone treatment. As expected, treatment with the PPARγ activator rosiglitazone improved insulin sensitivity in humans. Myocellular SCD1 messenger RNA expression was increased in human biopsies and C2C12 cells. Although the total content of myocellular LC-FA was unchanged, a relative shift from saturated LC-FAs to unsaturated LC-FAs was observed in human biopsies. Particularly, the amount of stearate was reduced, whereas the amounts of palmitoleate as well as oleate and vaccenate were increased, after rosiglitazone therapy. These changes resulted in an increased fatty acid Δ9-desaturation index (16:1/16:0 and 18:1/18:0) in skeletal muscle and a decreased elongase activity index (18:0/16:0). The PPARγ associated phenotypes may be partially explained by an increased Δ9-desaturation and a decreased elongase activity of skeletal muscle.
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Affiliation(s)
- Knut Mai
- Department of Endocrinology, Diabetes and Nutrition, Charite-University Medicine Berlin, Campus Benjamin Franklin, Berlin, Germany
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Aguer C, Foretz M, Lantier L, Hebrard S, Viollet B, Mercier J, Kitzmann M. Increased FAT/CD36 cycling and lipid accumulation in myotubes derived from obese type 2 diabetic patients. PLoS One 2011; 6:e28981. [PMID: 22194967 PMCID: PMC3241688 DOI: 10.1371/journal.pone.0028981] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2011] [Accepted: 11/18/2011] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Permanent fatty acid translocase (FAT/)CD36 relocation has previously been shown to be related to abnormal lipid accumulation in the skeletal muscle of type 2 diabetic patients, however mechanisms responsible for the regulation of FAT/CD36 expression and localization are not well characterized in human skeletal muscle. METHODOLOGY/PRINCIPAL FINDINGS Primary muscle cells derived from obese type 2 diabetic patients (OBT2D) and from healthy subjects (Control) were used to examine the regulation of FAT/CD36. We showed that compared to Control myotubes, FAT/CD36 was continuously cycling between intracellular compartments and the cell surface in OBT2D myotubes, independently of lipid raft association, leading to increased cell surface FAT/CD36 localization and lipid accumulation. Moreover, we showed that FAT/CD36 cycling and lipid accumulation were specific to myotubes and were not observed in reserve cells. However, in Control myotubes, the induction of FAT/CD36 membrane translocation by the activation of (AMP)-activated protein kinase (AMPK) pathway did not increase lipid accumulation. This result can be explained by the fact that pharmacological activation of AMPK leads to increased mitochondrial beta-oxidation in Control cells. CONCLUSION/SIGNIFICANCE Lipid accumulation in myotubes derived from obese type 2 diabetic patients arises from abnormal FAT/CD36 cycling while lipid accumulation in Control cells results from an equilibrium between lipid uptake and oxidation. As such, inhibiting FAT/CD36 cycling in the skeletal muscle of obese type 2 diabetic patients should be sufficient to diminish lipid accumulation.
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Affiliation(s)
- Celine Aguer
- INSERM, U1046 Physiologie et Médecine Expérimentale du Cœur et des Muscles, Montpellier, France
- Université Montpellier 1, Université Montpellier 2, Montpellier, France
| | - Marc Foretz
- Inserm, U1016, Institut Cochin, Paris, France
- CNRS, UMR8104, Paris, France
- Université Paris Descartes, Paris, France
| | - Louise Lantier
- Inserm, U1016, Institut Cochin, Paris, France
- CNRS, UMR8104, Paris, France
- Université Paris Descartes, Paris, France
| | - Sophie Hebrard
- Inserm, U1016, Institut Cochin, Paris, France
- CNRS, UMR8104, Paris, France
- Université Paris Descartes, Paris, France
| | - Benoit Viollet
- Inserm, U1016, Institut Cochin, Paris, France
- CNRS, UMR8104, Paris, France
- Université Paris Descartes, Paris, France
| | - Jacques Mercier
- INSERM, U1046 Physiologie et Médecine Expérimentale du Cœur et des Muscles, Montpellier, France
- Université Montpellier 1, Université Montpellier 2, Montpellier, France
- CHRU Montpellier, Montpellier, France
| | - Magali Kitzmann
- INSERM, U1046 Physiologie et Médecine Expérimentale du Cœur et des Muscles, Montpellier, France
- Université Montpellier 1, Université Montpellier 2, Montpellier, France
- * E-mail:
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Perreault L, Bergman BC, Hunerdosse DM, Howard DJ, Eckel RH. Fenofibrate administration does not affect muscle triglyceride concentration or insulin sensitivity in humans. Metabolism 2011; 60:1107-14. [PMID: 21306746 PMCID: PMC3135750 DOI: 10.1016/j.metabol.2010.12.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2010] [Revised: 11/24/2010] [Accepted: 12/09/2010] [Indexed: 11/21/2022]
Abstract
Animal data suggest that males, in particular, rely on peroxisome proliferator activated receptor-α activity to maintain normal muscle triglyceride metabolism. We sought to examine whether this was also true in men vs women and its relationship to insulin sensitivity (Si). Normolipidemic obese men (n = 9) and women (n = 9) underwent an assessment of Si (intravenous glucose tolerance test) and intramuscular triglyceride (IMTG) metabolism (gas chromatography/mass spectrometry and gas chromatography-combustion isotope ratio mass spectrometry from plasma and muscle biopsies taken after infusion of [U-(13)C]palmitate) before and after 12 weeks of fenofibrate treatment. Women were more insulin sensitive (Si: 5.2 ± 0.7 vs 2.4 ± 0.4 ×10(-4)/ μU/mL, W vs M, P < .01) at baseline despite similar IMTG concentration (41.9 ± 15.5 vs 30.8 ± 5.1 μg/mg dry weight, W vs M, P = .43) and IMTG fractional synthesis rate (FSR) (0.27%/h ± 0.07%/h vs 0.35%/h ± 0.06%/h, W vs M, P = .41) as men. Fenofibrate enhanced FSR in men (0.35 ± 0.06 to 0.54 ± 0.06, P = .05), with no such change seen in women (0.27 ± 0.07 to 0.32 ± 0.13, P = .73) and no change in IMTG concentration in either group (23.0 ± 3.9 in M, P = .26 vs baseline; 36.3 ± 12.0 in W, P = .79 vs baseline). Insulin sensitivity was unaffected by fenofibrate (P ≥ .68). Lower percentage saturation of IMTG in women vs men before (29.1% ± 2.3% vs 35.2% ± 1.7%, P = .06) and after (27.3% ± 2.8% vs 35.1% ± 1.9%, P = .04) fenofibrate most closely related to their greater Si (R(2) = 0.34, P = .10) and was largely unchanged by the drug. Peroxisome proliferator activated receptor-α agonist therapy had little effect on IMTG metabolism in men or women. Intramuscular triglyceride saturation, rather than IMTG concentration or FSR, most closely (but not significantly) related to Si and was unchanged by fenofibrate administration.
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Affiliation(s)
- Leigh Perreault
- Division of Endocrinology, Metabolism and Diabetes, University of Colorado Denver School of Medicine, Aurora, CO 80045, USA.
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