Preconditioning with cordycepin attenuates myocardial ischemia-reperfu-sion injury in SD rats / 中国病理生理杂志

ABSTRACT

AIM:To study whether cordycepin (Cordy) plays a role in myocardial protection by regulating the expression of microRNA-455 ( miR-455) and reducing apoptosis induced by endoplasmic reticulum stress in the ischemia -reperfusion (IR) rats.METHODS: SD rats (250 ~300 g) were randomly divided into 3 groups: control group, the chests of the rats were only opened;IR group, the rats were given myocardial ischemia for 30 min, and then reperfusion for 120 min;IR+Cordy group:before IR, the rats were given Cordy (10 mg/kg) through femoral vein injection once a day for one week, and the last injection was given 30 min before ischemia.Automated biochemical analysis was used to detect rat serum activity of LDH and CK-MB.The myocardial endothelial cell ( EC) apoptotic rate was measured by TUNEL , and the ultrastructural changes of the myocardial EC were observed under transmission electron microscope .RT-qPCR was used to detect the expression of miR-455 and the mRNA levels of glucose-regulated protein 78 ( Grp78) and caspase-12 in the myo-cardium.RESULTS:Compared with control group, EC apoptosis in IR group was significantly increased (P<0.05). Compared with IR group , EC apoptosis in IR +Cordy group decreased significantly ( P<0.05 ) .Compared with control group, swelling of mitochondria , irregular membrane , loose wrinkles with vacuoles , disappeared matrix granules , irregular nuclear membrane , chromatin condensation , disappeared nucleoli and even small apoptosis body in the EC were found in IR group.Compared with IR group , the symptoms in IR +Cordy group were greatly improved .Compared with control group, the mRNA expression of Grp78 and caspase-12 as well as the miR-455 level in IR group was increased (P<0.05). Compared with IR group , the mRNA expression of Grp78 and caspase-12, as well as the miR-455 level in IR+Cordy group was decreased (P<0.05).CONCLUSION:Cordycepin attenuates myocardial EC apoptosis , down-regulates the expres-sion of miR-455, and inhibits endoplasmic reticulum stress in the myocardium .