Ablation of CCDC8 provides cardioprotection against cardiomyocyte apoptosis via TNF signaling pathway in myocardial ischemia reperfusion injury

Aims: Myocardial ischemia-reperfusion (I/R) injury induces significant apoptosis and reactive oxygen species (ROS) accumulation in cardiomyocytes. Coiled-coil domain-containing 8 (CCDC8), recently identified as an interacting protein of p53, acts as a cofactor in p53-mediated apoptosis. However, its role in myocardial I/R injury remains unclear. Materials and methods: We first assessed CCDC8 levels in patients with left ventricular failure (LVF) and in both in vivo and in vitro models of myocardial I/R injury. Next, we used adenovirus 9 (AAV9) to overexpress CCDC8 and small interfering RNA (siRNA) to investigate the role of CCDC8 in myocardial I/R injury. mRNA sequencing and KEGG pathway analysis were performed to identify CCDC8-regulated genes. In vitro experiments were conducted to examine the effects of CCDC8 silencing on TNF-alpha-induced apoptosis. Key findings: CCDC8 expression was elevated in the left ventricle of LVF patients and in the cardiomyocytes of mice subjected to myocardial I/R injury. Overexpression of CCDC8 in cardiomyocytes via AAV9 exacerbated cardiac dysfunction caused by myocardial I/R injury, while silencing CCDC8 suppressed apoptosis and ROS production in H9c2 cells under hypoxia-reoxygenation (H/R) conditions. mRNA sequencing and KEGG analysis indicated that CCDC8 regulates genes related to cardiac contractility and the TNF signaling pathway. Additionally, CCDC8 silencing reversed TNF-alpha-induced cardiomyocyte apoptosis in vitro. Significance: This study identifies CCDC8 as a key mediator of cardiomyocyte apoptosis via the TNF signaling pathway in myocardial I/R injury. These findings suggest that targeting CCDC8 could be a potential therapeutic strategy for mitigating cardiac dysfunction in myocardial I/R injury.