Obeticholic Acid Inhibit Mitochondria Dysfunction Via Regulating ERK1/2‐DRP Pathway to Exert Protective Effect on Lipopolysaccharide‐Induced Myocardial Injury

Abstract Farnesoid X receptor (FXR) plays critical regulatory roles in cardiovascular physiology/pathology. However, the role of FXR agonist obeticholic acid (OCA) in sepsis‐associated myocardial injury and underlying mechanisms remain unclear. C57BL/6J mice are treated with OCA before lipopolysaccharide (LPS) administration. The histopathology of the heart and assessment of FXR expression and mitochondria function are performed. To explore the underlying mechanisms, H9c2 cells, and primary cardiomyocytes are pre‐treated with OCA before LPS treatment, and extracellular signal‐regulated protein kinase (ERK) inhibitor PD98059 is used. LPS‐induced myocardial injury in mice is significantly improved by OCA pretreatment. Mechanistically, OCA pretreatment decreased reactive oxygen species (ROS) levels and blocked the loss of mitochondrial membrane potential (ΔΨm) in cardiomyocytes. The expression of glutathione peroxidase 1 (GPX1), superoxide dismutase 1 (SOD1), superoxide dismutase 2 (SOD2), and nuclear factor erythroid 2‐related factor 2 (NRF‐2) increased in the case of OCA pretreatment. In addition, OCA improved mitochondria respiratory chain with increasing Complex I expression and decreasing cytochrome C (Cyt‐C) diffusion. Moreover, OCA pretreatment inhibited LPS‐induced mitochondria dysfunction via suppressing ERK1/2‐DRP signaling pathway. FXR agonist OCA inhibits LPS‐induced mitochondria dysfunction via suppressing ERK1/2‐DRP signaling pathway to protect mice against LPS‐induced myocardial injury.