TMBIM1 ameliorates sepsis-induced cardiac dysfunction by promoting Parkin-mediated mitophagy

Abstract

Myocardial dysfunction is a significant complication of sepsis that is associated with elevated mortality rates. Transmembrane BAX inhibitor motif containing 1 (TMBIM1), a stress-responsive protein, has garnered interest in the field of cardiovascular disease for its cardioprotective properties. Nevertheless, the role of TMBIM1 on sepsis-induced cardiac dysfunction (SICD) remains unknown. Here, our findings revealed a significant elevation in TMBIM1 expression within the myocardium following endotoxin challenge and further demonstrate the cardioprotective effects of TMBIM1 through adenovirus-mediated gene manipulation. Notably, lipopolysaccharide exposure markedly induced mitochondrial dysfunction in cardiomyocytes, which was effectively alleviated by TMBIM1 overexpression, while TMBIM1 knockdown exacerbated this dysfunction. Moreover, in cardiomyocytes subjected to endotoxin challenge, TMBIM1 was observed to interact with Parkin, facilitating its translocation from the cytosol to damaged mitochondria. This interaction enhanced the activation of mitophagy, thereby promoting the clearance of dysfunctional mitochondria and subsequently mitigating cellular injury. Hence, targeting TMBIM1 could be a novel therapeutic strategy for treating SICD.