Intramyocellular lipid accumulation is associated with permanent relocation ex vivo and in vitro of fatty acid translocase (FAT)/CD36 in obese patients

Archive ouverte

Aguer, C | Mercier, Jacques | Yong Wai Man, C | Metz, L. | Bordenave, S. | Lambert, Karen | Jean, E | Lantier, L | Bounoua, L | Brun, Jean-Frédéric | Raynaud, E. | Andreelli, F. | Foretz, M | Kitzmann, M

Edité par CCSD ; Springer Verlag -

International audience. Aims/hypothesis Intramyocellular lipids (IMCL) accumulation is a classical feature of metabolic diseases. We hypothesised that IMCL accumulate mainly as a consequence of increased adiposity and independently of type 2 diabetes. To test this, we examined IMCL accumulation in two different models and four different populations of participants: muscle biopsies and primary human muscle cells derived from non-obese and obese participants with or without type 2 diabetes. The mechanism regulating IMCL accumulation was also studied.Methods Muscle biopsies were obtained from ten non-obese and seven obese participants without type 2 diabetes, and from eight non-obese and eight obese type 2 diabetic patients. Mitochondrial respiration, citrate synthase activity and both AMP-activated protein kinase and acetyl-CoA carboxylase phosphorylation were measured in muscle tissue. Lipid accumulation in muscle and primary myotubes was estimated by Oil Red O staining and fatty acid translocase (FAT)/CD36 localisation by immunofluorescence.Results Obesity and type 2 diabetes are independently characterised by skeletal muscle IMCL accumulation and permanent FAT/CD36 relocation. Mitochondrial function is not reduced in type 2 diabetes. IMCL accumulation was independent of type 2 diabetes in cultured myotubes and was correlated with obesity markers of the donor. In obese participants, membrane relocation of FAT/CD36 is a determinant of IMCL accumulation.Conclusions/interpretation In skeletal muscle, mitochon-drial function is normal in type 2 diabetes, while IMCL

Suggestions

Du même auteur

Whole-Body Lipid Oxidation during Exercise is Correlated to Insulin Sensitivity and Mitochondrial Function in Middle-Aged Obese Men

Archive ouverte | Lambert, Karen | CCSD

International audience. Defects in insulin sensitivity are associated with metabolic inflexibility and obesity albeit some obese subjects have preserved insulin sensitivity. A decrease in lipid oxidation during exer...

Biomarkers of Redox Balance Adjusted to Exercise Intensity as a Useful Tool to Identify Patients at Risk of Muscle Disease through Exercise Test

Archive ouverte | Grillet, Pierre-Edouard | CCSD

International audience. The screening of skeletal muscle diseases constitutes an unresolved challenge. Currently, exercise tests or plasmatic tests alone have shown limited performance in the screening of subjects w...

Functional muscle impairment in facioscapulohumeral muscular dystrophy is correlated with oxidative stress and mitochondrial dysfunction

Archive ouverte | Turki, Ahmed | CCSD

International audience

Chargement des enrichissements...