β-Hydroxybutyrate-induced mitochondrial dysfunction and oxidative stress in BMSCs are ameliorated by mitophagy...

Ketosis is a common metabolic disorder in periparturient dairy cows and is characterized by elevated circulating BHBA concentrations. Although the effects of ketosis on hepatic metabolism have been extensively studied, its impact on skeletal muscle remains poorly understood. This study investigated the effects of BHBA on bovine muscle satellite cells (BMSCs) and the role of mitochondrial quality control in BHBA-induced cellular injury. BHBA treatment significantly inhibited BMSC proliferation, promoted apoptosis, increased intracellular and mitochondrial ROS accumulation, reduced antioxidant enzyme activities, and impaired mitochondrial membrane potential in a dose-dependent manner. BHBA also disrupted mitochondrial ultrastructure, altered the expression of mitochondrial respiratory chain genes, promoted mitochondrial fission, and suppressed mitophagy. Similar effects were observed in C₂C₁₂ myoblasts, indicating that the detrimental effects of BHBA on myogenic cells are conserved across different cellular models. Notably, activation of mitophagy alleviated BHBA-induced oxidative stress, reduced ROS accumulation, improved antioxidant capacity, and enhanced ketone body metabolism, whereas inhibition of mitophagy exacerbated these alterations. These findings demonstrate that BHBA directly induces oxidative damage and mitochondrial dysfunction in myogenic cells. Impaired mitophagy contributes to the progression of cellular injury, whereas enhancement of mitochondrial quality control confers protection. This study provides new insights into the cellular mechanisms underlying skeletal muscle metabolic dysfunction during bovine ketosis and identifies mitophagy as a potential therapeutic target.