Upregulation of SLAMF8 aggravates ischemia/reperfusion-induced ferroptosis and injury in cardiomyocyte

Background Myocardial infarction (MI) is a cardiovascular diseases, that seriously threatens human life. Signaling lymphocytic activation molecule family member 8 (SLAMF8) has been discovered to regulate the development and function of many immune cells. However, there are limited reports on SLAMF8 in the field of cardiopathy, and its regulatory role also remains unclear. Methods The mRNA and protein expressions of genes were examined through RT-qPCR and western blot. The infarct size in heart was assessed through TTC staining. The pathological section of heart tissue was evaluated through HE staining. The iron, Fe2+, MDA and SOD levels were assessed through the corresponding commercial kits. The ROS level was detected through Immunofluorescence (IF) staining. The cell viability and cell apoptosis were assessed through MTT assay and flow cytometry. Results Through GEO (GSE84796) database, SLAMF8 exhibited higher expression in heart failure patients. Furthermore, the ischemia/reperfusion SD rat (ischemia/reperfusion, I/R treatment) and H9C2 cell (hypoxia/reoxygenation, H/R treatment) models were set up. The mRNA and protein levels of SLAMF8 were upregulated in ischemia/reperfusion SD rat and H9C2 cell models. In addition, SLAMF8 inhibition alleviated ischemia/reperfusion-induced myocardial injury in SD rats. Moreover, SLAMF8 suppression inhibited ischemia/reperfusion-induced ferroptosis and oxidative stress. Further experiments were performed in H/R stimulated H9C2 cells, and the results showed that SLAMF8 knockdown alleviated H/R-induced cardiomyocyte death, ferroptosis and oxidative stress in H/R-induced cardiomyocyte. Lastly, SLAMF8 activated the TLR4/NOX4 pathway in I/R treated-SD rats or H/R treated-H9C2 cells. Conclusion SLAMF8 aggravated ischemia/reperfusion-induced ferroptosis and injury in cardiomyocyte. This discovery may provide a useful bio-target for MI treatment.