Muscle Immune Cells, Obesity, and High-Fat Feeding

Skeletal muscle metabolism is a highly coordinated process involving cross talk between immune and muscle cells. However, the physiological activities of both immune and muscle cells are modified with obesity or high-fat feeding. In this context, skeletal muscle inflammation occurs as a result of immune cell infiltration and activation. The subsequent myocyte metabolic alteration leads to insulino-resistance development. Several studies demonstrate that skeletal muscle repair is reduced during obesity. Interestingly, characteristics of aged muscle contributing to the reduction of muscle repair capacity are observed in obesity such as reduced number and activity of muscle satellite cells, decreased muscle cell differentiation, muscle adipose tissue deposition, modification of macrophage infiltration and phenotype. Obesity likely increases the risk of developing a phenomenon named sarcopenic obesity. This research will highlight new strategies to improve skeletal muscle repair and then limit the adverse effects of obesity on skeletal muscle health.