EGCG Alleviates\nSkeletal Muscle Oxidative Damage in\nHeat-Stressed Pigs via Keap1/PGAM5 Complex-Mediated Mitophagy

The heat stress (HS) induced by high temperatures can\nresult in\noxidative damage to muscles, thereby compromising both muscle growth\nand immune function within the organism. Mitophagy serves as a pivotal\npathway in alleviating excessive ROS production and subsequent oxidative\ndamage. However, the potential role of epigallocatechin-3-gallate\n(EGCG), a natural antioxidant found in tea, in mitophagy under HS\nremains unexplored. Here, we present evidence of EGCG mitigating the\noxidative–redox imbalance in porcine skeletal muscles induced\nby HS involving the antioxidant enzyme system mediated by the Keap1/Nrf2\npathway and mitophagy mediated by the PINK1/Parkin pathway. Importantly,\nwe identified phosphate mutase 5 (PGAM5) for the first time as a key\nprotein modulated by EGCG under HS conditions, regulating mitophagy.\nInhibition of PGAM5 significantly attenuated the activation of mitophagy\nby EGCG. Molecular docking and dynamics simulations further suggested\nthat EGCG directly binds to Keap1, disrupting the Keap1–PGAM5\nprotein interaction and thus promoting the release of PGAM5 and subsequently\nactivating mitophagy. In summary, this study represents the first\ndiscovery of EGCG directly targeting Keap1/PGAM5-mediated mitophagy,\nwhich serves as a potential functional supplement for regulating the\nantioxidant capacity in pigs.