丹参酮IIA调节钙蛋白酶-1减轻心肌缺血再灌注损伤OA

Objective:To explore the protective effects and underlying mechanisms of tanshinone IIA on myocardial ischemia-reperfusion injury(MI/RI)from the perspective of calpain-1.Methods:In vivo,an MI/RI model was estab-lished by left anterior descending coronary artery ligation in SD rats.Rats were randomly assigned to sham-operated con-trol,model control,tanshinone IIA(5,10,20 mg/kg)groups,and calpain-1 inhibitor III(MDL-28170)as a positive control.In vitro,H9c2 cardiomyocytes were subjected to hypoxia-reoxygenation,with the same grouping as in vivo.Myo-cardial infarct size was measured by NBT staining,cardiac function was evaluated by echocardiography,myocardial apop-tosis was assessed using TUNEL assay,and reactive oxygen species(ROS)levels in tissues and cells were determined by DHE staining.Levels of lactate dehydrogenase(LDH),creatine kinase-MB(CK-MB),malondialdehyde(MDA),and superoxide dismutase(SOD),as well as calpain-1 activity,were measured using assay kits.Mitochondrial membrane po-tential(MMP)was examined by JC-1 staining.Calpain-1 and sarco/endoplasmic reticulum Ca2+-ATPase(SERCA2a)protein expression was analyzed by Western blot,and intracellular Ca2+levels were measured using Fluo-3/AM.The binding affinity of tanshinone IIA to calpain-1 was evaluated by molecular docking.Results:Compared with the sham-op-erated control group,the model control group showed increased myocardial infarct size,decreased LVEF and LVFS,in-creased LVEDD and LVESD,elevated serum LDH and CK-MB,increased cardiomyocyte apoptosis,elevated ROS and MDA levels,decreased SOD activity,upregulated calpain-1,and downregulated SERCA2a protein expression(P<0.01).Compared with the model control group,tanshinone IIA(20 mg/kg)and MDL-28170 groups exhibited improved LVEF and LVFS,reduced LVEDD and LVESD,decreased serum LDH and CK-MB,reduced apoptosis,ROS,and MDA levels,increased SOD activity,downregulated calpain-1,and upregulated SERCA2a expression(P<0.05 or P<0.01).In vitro results were consistent with in vivo findings regarding oxidative stress,apoptosis,and expressions of calpain-1/SERCA2a protein.Additionally,in vitro experiments revealed that compared with the normal control group,the model control group showed significantly increased calpain-1 activity and intracellular Ca2+levels(P<0.01).Compared with model control group,tanshinone IIA and MDL-28170 treatment significantly reduced calpain-1 activity and Ca2+level(P<0.05 or P<0.01).Molecular docking analysis revealed a strong binding affinity between tanshinone IIA and calpain-1.Conclu-sion:Tanshinone IIA protects against MI/RI,potentially by inhibiting calpain-1,upregulating SERCA2a expression,and thereby suppressing cardiomyocyte apoptosis,oxidative stress,and Ca2+overload.