Effect Of CD47 Antibody On Rat Myocardial Cell Injury Induced By Acute Hypoxia/Reoxygenation

Background Reperfusion therapy is the most commonly used treatment for ischemic heart disease,but it can cause myocardial ischemia reperfusion injury(I/R).I/R is a common pathophysiological phenomenon in clinical cardiology and thoracic surgery.For example,I/R injury can occur in patients with myocardial infarction after thrombolysis or reperfusion after interventional therapy,or after cardiopulmonary bypass after cardiac surgery.Myocardial ischemia reperfusion injury is a series of injury manifestations of myocardial cells in morphology,function,metabolism,electrophysiology and other aspects after coronary artery recanalization to restore blood supply to ischemic myocardium.The serious complications caused thereby are the main causes of postoperative death.I/R injury can affect the normal systolic function of the heart muscle and affect the prognosis of the disease.I/R injury is the leading cause of heart failure worldwide.This damage activates apoptosis and autophagy,leading to cell death.Reducing or preventing I/R injury by effective intervention is an important clinical issue.Studies have shown that the use of anti-CD47 monoclonal antibodies to block TSP1/CD47 signals,or the use of CD47 knockout mice,can reduce kidney,liver,heart and tissue flap damage,and improve tissue survival in the ischemia/reperfusion model.Objective In this study,the hypoxia/reoxygenation injury model of rat cardiomyocytes was adopted to explore the effects and mechanism of closed CD47 on hypoxia/reoxygenation injury of cardiomyocytes in vitro culture from the aspects of anti-oxidation and anti-apoptosis,so as to provide the basic theoretical basis for its clinical application.Methods Myocardial hypoxia/reoxygenation model was established on cultured primary myocardial cells of neonatal rat.The following sets of experiments was performed:control group,model group(H/R group),CD47+H/R group.Cultured supernatants were collected to measure lactic dehydrogenase(LDH),creatine kinase(CK),superoxide dismutase(SOD),malonadehyde(MDA),nitric oxide(NO)and reactive oxygen species(ROS)and the myocardial apoptosis rate was detected using annexin-V and PI double staining and flow cytometry;DHE(dihydroethidium)staining was used to detected ROS in cardiomyocytes;The expression of CD47,eNOS and p-eNOS was detected using western blotResults Compared with the control group,cardiacmyocyte apoptosis rate in H/R group significantly increased(P<0.01);Compared with the H/R group,cardiacmyocyte apoptosis rate in CD47+H/R group significantly decreased(P<0.01)Compared with the control group,the levels of LDH,CK,MDA,and ROS in H/R group significantly increased(P<0.01),the levels of SOD and NO in H/R group significantly decreased(P<0.01);Compared with the H/R group,the levels of LDH,CK,MDA and ROS in CD47+H/R group significantly decreased(P<0.01),the levels of SOD and NO in H/R group significantly increased(P<0.01).The results of western blotting showed that compared with the control group,the expression of CD47 in H/R group increased markedly(P<0.01),the expression of p-eNOS in H/R group decreased markedly(P<0.01),compared with H/R group,the expression of CD47 in CD47+H/R group decreased significantly(P<0.01);the expression of p-eNOS in H/R group increased significantly(P<0.05)Conclusion Blockage of CD47 has protective effect on hyPoxia/complex oxygen injury in cardiacmyocyte in rats.The mechanism may be to activate the eNOS/NO pathway to make up-regulated expression of NO in rat cardiacmyocyte.