Cortright 2015 Abstract MiPschool Greenville 2015
|Intramyocellular triacylglycerol is associated with peroxisomal biogenesis in skeletal muscle from lean and obese humans.|
Event: MiPschool Greenville 2015
Obesity is associated with elevated levels of lipids (intramyocellular triacylglycerols; IMTG) and reductions in mitochondrial fatty acid oxidation in skeletal muscle, both which are associated with insulin resistance. Known predominately for their actions in liver, peroxisomes are subcellular compartments essential for lipid disposal by chain-shortening very long- and long-chain fatty acids to acyl-carnitines, permitting CPT-1 independent entry into the mitochondria for oxidation. We hypothesized that peroxisome proliferation in human skeletal muscle occurs as an adaptive response to elevated lipid supply and accumulation (IMTG) which could facilitate mitochondrial fatty acid oxidation. Assays for the peroxisomal biogenesis marker PEX19 protein content and IMTG were assessed using vastus lateralis from obese and lean humans. Peroxisomal membrane protein 70 (PMP70) was measured after lipid incubation of human skeletal muscle primary myotubes.
1) A significant relationship between tissue IMTG and PEX19 was identified in human skeletal muscle tissue (P<0.05) but not % body fat or BMI 2) PEX19 protein content was elevated (P<0.05) in tissues from obese individuals with high IMTG and 3) An increase in peroxisomal PMP70 was observed (P<0.05) with high fat incubation of human primary myotubes.
This is the first report associating lipid oversupply, IMTG accumulation, and peroxisomal biogenesis in human skeletal muscle suggesting a functional-adaptive role for peroxisomes in mitochondrial lipid oxidation and obesity.
• O2k-Network Lab: US NC Greenville Neufer PD
Labels: MiParea: Exercise physiology;nutrition;life style Pathology: Obesity
Organism: Human Tissue;cell: Skeletal muscle
1-Kinesiology; 2-Physiology; 3-Diabetes Obesity Inst, East Carolina Univ, Greenville, NC, USA. - [email protected]