生存素在胰岛素抑制大鼠心肌微血管内皮细胞缺血再灌注损伤中的关键作用

目的探讨生存素(survivin,SVV)在胰岛素(Ins)抑制大鼠心肌微血管内皮细胞(cardiac microvascular endothelial cell,CMECs)缺血再灌注损伤中的作用。方法分离培养大鼠CMECs,建立模拟缺血再灌注(SI/R)模型,随机分为对照组、对照+Ins组、SI/R组、SI/R+Ins组、SI/R+Ins+SVV RNA干扰组(SVV RNAi组)。采用MTT检测细胞增殖能力,划痕实验检测细胞迁移能力,TUNEL法检测细胞凋亡指数,Western blot法检测SVV蛋白表达。结果与对照组比较,SI/R组和SI/R+Ins组CMECs增殖能力明显降低(P<0.01),凋亡指数明显升高(P<0.01)。与SI/R组比较,SI/R+Ins组CMECs增殖能力明显升高(P<0.01),细胞迁移率升高(P<0.05),凋亡指数明显降低(P<0.01)。与对照组和SI/R组比较,SI/R+Ins组SVV表达明显升高(P<0.05)。RNAi抑制SVV表达后,在SI/R+Ins处理中,与未转染对照组和β-actin转染组比较,SVV RNAi组凋亡指数明显升高(P<0.01)。结论胰岛素可显著抑制缺血再灌注损伤诱导的CMECs凋亡,促进CMECs存活,改善细胞功能,其保护作用可能与上调SVV蛋白表达相关。

Insulin protects cardiac microvascular endothelial cells against IR injury, the key role of survivin

Objective To detect the role of survivin(SVV) in the cardioprotective effect of insulin against ischemia reperfusion injury(SI/R) of cardiac microvascular endothelial cells(CMECs). Methods CMECs isolated from the hearts of adult rats were exposed to hypoxia(94%N_2,5% CO_2,1%O_2) for 2 h followed by 3 h reoxygenation(95%air,5%CO_2).The cell viability of CMECs was measured by MTT assay and migration ability of CMECs was detected by cell scratch wound assay.The apoptosis of CMECs was detected by TUNEL method.The expression of SVV was analyzed by Western blot.Results Both cell viability and migration ability were impaired after SI/R(P<0.01 vs control),and the apoptosis index was increased in comparison with control group(P<0.01).While administration of insulin during reperfusion dramatically attenuates the dysfunction of CMECs and up-regulates the expression of SVV.To further ascertain the role of SVV in insulin-induced cardioprotective effect,CMECs were transfected with siRNA-targeting SVV.While siRNA-targeting SVV significantly blunted the anti-apoptotic effect of insulin.Conclusion Insulin could significantly inhibit the apoptosis of CMECs induced by SI/R through up-regulating SVV expression.