Objective To elucidate how Tongmai Yangxin Pill (通脉养心丸, TMYX) confers cardioprotective effects during myocardial ischemia/reperfusion injury (MI/RI) through the regulation of peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α)-mediated mitochondrial function. Methods A hypoxia-reoxygenation (H/R) model in cardiomyocytes was established. After intervention with TMYX, intracellular reactive oxygen species (ROS) levels were measured using DCFH-DA and MitoSOX^TM red fluorescent probes. Cellular adenosine triphosphate (ATP) content was quantified using an enhanced ATP assay kit. Changes in mitochondrial membrane potential were evaluated by JC-1 staining. Mitochondrial respiratory function was assessed using Seahorse XF cell mitochondrial stress test. Mitochondrial morphology and ultrastructural alterations were examined using MitoTracker staining and transmission electron microscopy. Western blotting and qRT-PCR were used to determine the expression levels of proteins and genes associated with mitochondrial fusion and fission [mitofusin 1 (Mfn1), mitofusin 2 (Mfn2), fission 1 (Fis1), dynamin-related protein 1 (Drp1)], biogenesis [nuclear respiratory factor 1 (Nrf1), mitochondrial transcription factor A (TFAM), mitochondrial DNA (mtDNA) copy number] and autophagy [Beclin1, PTEN-induced putative kinase 1 (PINK1), Parkin, p62]. To further investigate the effects of TMYX on the above-mentioned functions of H9c2 cells after PGC-1α silencing expression through PGC-1α siRNA transfection experiment. Results Compared with model group, TMYX significantly enhanced mitochondrial ATP synthesis (P < 0.01), improved mitochondrial membrane potential (P < 0.01), reduced oxidative stress (P < 0.01), and promoted mitochondrial autophagy (P < 0.05, 0.01). After silencing PGC-1α, the protective effect of TMYX on mitochondrial function was significantly weakened (P < 0.05, 0.01). Conclusion TMYX could effectively improve mitochondrial dysfunction and morphological changes induced by MI/RI by regulating mitochondrial biosynthesis, dynamic balance and autophagy through PGC-1α. This study reveals PGC-1α as a core factor regulating mitochondrial function and its potential therapeutic value in MI/RI, providing new ideas for the treatment of MI/RI.

Tongmai Yangxin Pill  /  myocardial ischemia-reperfusion injury  /  mitochondrial function  /  cardiomyocyte injury  /  peroxisome proliferator-activated receptor gamma coactivator-1α