p38α MAPK Regulation of Energy Metabolism in Skeletal Muscle Offers a Therapeutic Path for Type 2 Diabetes

Type 2 diabetes (T2D), a growing global health concern, is closely linked to obesity and sedentary behavior. Central to its development are insulin resistance and impaired glucose metabolism in peripheral tissues, particularly skeletal muscle, which plays a key role in energy expenditure, glucose uptake, and insulin sensitivity. Notably, increased accumulation of lipid metabolites in skeletal muscle is observed both in endurance exercise-associated with improved insulin sensitivity-and in high-fat diets that induce insulin resistance. The review examines the contrasting metabolic adaptations of skeletal muscle to these opposing conditions and highlights the key signaling molecules involved. The focus then shifts to the role of the stress kinase p38α mitogen-activated protein kinase (MAPK) in skeletal muscle adaptation to overnutrition and endurance exercise. p38α enhances mitochondrial oxidative capacity and regulates nutrient utilization, both critical for maintaining metabolic homeostasis. During exercise, it cooperates with AMP-activated protein kinase (AMPK) to boost glucose uptake and fatty acid oxidation, key mechanisms for improving insulin sensitivity. The co-activation of p38α and AMPK in skeletal muscle emerges as a promising therapeutic avenue to combat insulin resistance and T2D. The review explores strategies for selectively enhancing p38α activity in skeletal muscle. In conclusion, it advocates a comprehensive approach to T2D prevention and treatment, combining established caloric intake-reducing therapies, such as GLP-1 receptor agonists, with interventions aimed at increasing energy expenditure via activation of p38α and AMPK signaling pathways.