血管内皮生长因子165通过抑制钙敏感性受体减少缺血/再灌注心肌细胞凋亡

目的:探讨血管内皮生长因子165(vascu-lar endothelial growth factor 165,VEGF165)在缺血/再灌注损伤中的抗细胞凋亡作用及与钙敏感性受体(calciumsensing receptor,CaSR)表达下调的关系。方法:新生鼠心肌细胞在模拟心肌缺血状态下孵育2 h,然后在标准培养液中再培养24 h,从而建立一个模拟心肌缺血/再灌注模型。通过末端脱氧核苷酰基转移酶介导性dUTP切口末端标记(TUNEL法)检测心肌细胞凋亡。CaSR mRNA表达通过逆转录聚合酶链反应(RT-PCR)测定。通过免疫印迹法(Westernblot)测定促凋亡蛋白Bax、抗凋亡蛋白Bcl-2含量。结果:模拟的缺血/再灌注后CaSR mRNA的表达(I/R组:2.6±0.4;对照组:1.0±0.3,P<0.01)和TUNEL阳性细胞增加(I/R组:15.3%±2.5%;对照组:2.9%±1.4%,P<0.01)。GdCl3、CaSR mRNA的表达(GdCl3组:4.5±0.6;I/R组:2.6±0.4,P<0.01)及TUNEL阳性细胞进一步增加(GdCl3组:25.4%±2.6%;I/R组:15.3%±2.5%,P<0.01),同时上调了Bax表达(GdCl3组:1.93±0.28;I/R组:1.50±0.21,P<0.01),下调了Bcl-2的表达(GdCl3组:0.82±0.18;I/R组:1.71±0.30,P<0.01)。VEGF165组Bax表达减少(GdCl3+VEGF165组:1.12±0.23;GdCl3组:1.93±0.28,P<0.05)和Bcl-2的表达增加(GdCl3+VEGF165组:2.56±0.54;GdCl3组:0.82±0.18,P<0.05),TUNEL阳性细胞减少(GdCl3+VEGF165组:11.8%±1.9%;GdCl3组:25.4%±2.6%,P<0.05),CaSR mRNA的表达下调(GdCl3+VEGF165组:1.5±0.4;GdCl3组:4.5±0.6,P<0.01)。结论:VEGF165通过抑制CaSR,促进Bcl-2和抑制Bax的表达来减少缺血/再灌注诱导的心肌细胞凋亡。

VEGF165 reduced apoptosis by regulation of CaSR expression in ischemia/reperfusion cardiomyocytes

AIM : To examine whether anti-apoptotic role of VEGF165 is associated with downregulation of CaSR expression in ischemia/reperfusion cardiomyocytes. METHODS : We incubated primary neonatal rat ventricular cardiomyocytes in ischemia-mimetic solution for 2 h,then re-incubated them in normal culture medium for 24 h to establish a model of simulated ischemia/reperfusion(I/R).Cardiomyocyte apoptosis was detected by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling(TUNEL).The expression of CaS...