Muscle Compression Causes Reduction of Oxidative Phosphorylation (oxphos) Subunits and Increase in Autophagy

Pressure‐induced injury, skeletal muscle apoptosis and nitrosative stress can be induced in skeletal muscle by moderate mechanical compression in our established mouse model. Nonetheless, the effects of mechanical compression on oxidative phosphorylation (OXPHOS) subunits content and autophagic signalling in compressed skeletal muscle are largely unknown.PURPOSETo determine whether mechanical compression decreases the content of OXPHOS subunits and triggers autophagy in skeletal muscle.METHODSA single session of 4‐hour compression with static pressure of 150 mmHg was applied over the right lateral gastrocnemius muscle of mice. Tissues were harvested 48 hours after compression for analysis.RESULTSOur immunoblot data suggest that mechanical compression decreases OXPHOS subunits content. Furthermore, mechanical compression triggers autophagy in compressed skeletal muscle, resulting in increase in LC3‐II protein abundance and decrease in p62 protein abundance.CONCLUSIONThese results suggest that moderate mechanical compression leads to degradation of mitochondrial complexes which might impair the OXPHOS activity and, hence, the mitochondrial function. The degradation of mitochondrial complexes might possibly be induced by the upregulation of autophagy.Support or Funding InformationSupported by The Hong Kong Polytechnic University Research Funds (A‐PH69 and G‐U645) and General Research Fund (PolyU 5632/10M).