Notch-1 in macrophages promoted the ischemia-reperfusion via modulating EZH2/HSF1/BRD4/SIRPα/SHP2 induced ROS and apoptosis in Cardiomyocyte

Objective To investigate the role of Notch-1 in macrophages and its related molecular mechanisms in influencing cardiomyocytes, thereby affecting the mechanisms of ischemia-reperfusion (I/R) injury. Methods Twenty-one male SD rats were purchased for in vivo experiments, and they were divided into sham group, Model group, and Model + Notch1-OE group. The cardiac function of each group, i.e., the left ventricular end-diastolic internal diameter (LVEDD), the left ventricular end-systolic internal diameter (LVESD), and the left ventricular ejection fraction (LVEF) was observed by ultrasonography, and the changes in the pathology of cardiac myocardial tissue were observed by HE staining. In the in vitro experiments, the protein expression of each group of RAW264.7 cells was detected by Western blot after different stimulation; the supernatant of RAW264.7 medium after different stimulation was used to stimulate cardiomyocytes, and apoptosis was detected by flow apoptosis assay. Results Notch-1 deteriorated the cardiac function of I/R rats, and at the same time, myocardial fibers were disorganized and severely fractured, with more hemorrhagic foci and severe edema of cardiomyocytes.Notch-1 played a role in apoptosis of cardiomyocytes by inhibiting the expression of EZH2 protein, and promoting the expression of HSF1, BRD4, membrane SIRPα, and membrane P-SHP2 proteins. Conclusion Notch-1 in macrophages induces excessive ROS generation by regulating the EZH2/HSF1/BRD4/SIRPα/SHP2 pathway, leading to cardiomyocyte apoptosis and exacerbating I/R injury.