细胞穿透肽4介导的Cu/Zn SOD对缺氧复氧损伤心肌细胞的影响

目的 评价细胞穿透肽4(又称为蛋白转导结构域4,PTD4)介导的铜锌超氧化物歧化酶(Cu/Zn SOD)对大鼠心肌细胞缺氧复氧损伤(HRI)的影响.方法 用厌氧培养箱85%氮气(N2),10%氢气(H2),5% CO2]制作大鼠心肌细胞(H9c2)HRI模型,设置HRI组(HRI的细胞培养液中不加任何处理因素),HRI+Cu/Zn SOD组(加入10 μmol/L Cu/Zn SOD)、HRI+PTD4-Cu/Zn SOD组(加入10 μmol/L PTD4-Cu/Zn SOD),另外以正常培养心肌细胞作为正常对照组,孵育30 min后,透射电镜观察心肌线粒体超微结构,JC-1试剂盒检测线粒体膜电位,末端脱氧核苷酸转移酶(TdT)介导的dUTP缺口末端标记(TUNEL)技术检测心肌细胞凋亡.结果 PTD4-Cu/Zn SOD组线粒体损伤程度较HRI组有明显改善.与正常对照组比较,HRI组线粒体膜电位明显下降,PTD4-Cu/Zn SOD组线粒体膜电位低于正常对照组,但与HRI组比较明显恢复.HRI+PTD4-Cu/Zn SOD组心肌细胞凋亡指数(10.20±2.77)%]较HRI组(28.40±2.41)%]明显降低,差异有统计学意义(P<0.05).结论 PTD4介导的Cu/Zn SOD可以减轻大鼠心肌细胞的HRI.

Effects of Cu/Zn SOD mediated by cell penetrating peptide 4 on hypoxia/reoxygenation injury in myocardial cells

Objective To evaluate the effect of cell-penetrating peptide (protein transduction domain 4,PTD4) mediated copper-zinc superoxide dismutase (Cu/Zn SOD) on hypoxia/reoxygenation injury (HRI) in rat myocardial cells.Methods Rat myocardial cell H9C2 HRI model was prepared by using the anaerobic incubator (85% N2,10% H2,5% CO2).The HRI group (without adding any treating factor in HRI cell culture fluid),HRI+Cu/Zn SOD group (adding 10 μmol/L Cu/Zn SOD) and HRI+PTD4-Cu/Zn SOD group (10 μmol/L PTD4-Cu/Zn SOD) were set up.In addition,normally cultured myocardial cells served as the normal control group.After incubating for 30 min,the ultra microstructure of mitochondria was observed under transmission electron microscope.The mitochondrial membrane potential was detected by JC-1 kit.The myocardial cell apoptosis was detected by TdT mediated dUTP nick end labeling TUNEL technique.Results The mitochondria injury degree after 30 min incubation in the PTD4-Cu/Zn SOD group was significantly improved compared with the HRI group.Compared with the normal control group,the mitochondrial membrane potential in the HRI group was significantly decreased,while the mitochondrial membrane potential in the PTD4-Cu/Zn SOD group was lower than that in the normal control group,but compared with the HRI group,which was obviously recovered.The cardiomyocyte apoptosis in the HRI+PTD4-Cu/Zn SOD group was (10.20±2.77)%,which was significantly decreased compared with (28.40±2.41)% in the HRI group,the difference was statistically significant (P<0.05).Conclusion PTD4 mediated Cu/Zn SOD can attenuate HRI in rat myocardial cells.