NCOR1 alleviates myocardial infarction by improving lipid peroxidation through PPARG/PINK1-mediated mitophagy

Abnormal lipid accumulation following myocardial infarction (MI) serves as a critical pathological factor contributing to cardiomyocyte injury. The nuclear receptor corepressor 1 (NCOR1) is famous as a key regulator in atherosclerosis, fatty liver, and other metabolic diseases, and recent evidence suggested that NCOR1 exerted a protective action in damaged heart cells. In this study, in a murine MI model induced by left anterior descending coronary artery ligation, we observed a significant downregulation of NCOR1 in myocardial tissues. NCOR1 was also downregulated in oxygen-glucose deprivation (OGD)-treated H9C2 cells, in which NCOR1 overexpression improved lipid metabolic dysregulation and peroxidation. Mechanistically, NCOR1 interacted with peroxisome proliferator activated receptor gamma (PPARγ) protein, which transcriptionally activated the expression of the mitophagy marker gene PINK1. Either knockdown of PPARγ or PINK1 was able to reverse the improvement of NCOR1 overexpression on OGD-induced dysregulation of mitophagy, lipid peroxidation, and cardiomyocyte damage. Finally, we demonstrated that NCOR overexpression (mediated by lentiviral vector) reduced infarct size, attenuated myocardial damage, and significantly improved cardiac function in MI mice. These findings not only identify NCOR1 as a novel protector in hypoxic-ischemic myocardium but also delineate the "NCOR1-PPARγ-PINK1" axis as a novel mechanism for improving mitochondrial function and lipid peroxidation, offering a promising therapeutic target for MI treatment.