凝血酶大鼠脑内注射对细胞凋亡的影响及其机制的实验研究

目的探讨凝血酶(Thrombin,TM)脑内注射对周围组织Caspase-3蛋白表达和细胞凋亡的影响。方法TM、TM 组织蛋白酶G(Cathepsin G,CATG)、TM Caspase-3抑制剂(DEVD-fmk)脑内立体定向注射制作动物模型,应用Western-blot技术检测Caspase-3蛋白表达,TUNEL法检测细胞凋亡。结果TM脑内注射后6hCaspase-3蛋白开始增加,与对照组比较差异具有显著性(P<0.01),注射后24h达高峰(P<0.01),然后逐渐下降,96h时恢复至正常水平;TM脑内注射后24h凋亡细胞数目开始增加,与对照组比较差异具有显著性(P<0.05),48h达高峰(P<0.01),然后逐渐下降。TM DEVD-fmk脑内注射后凋亡细胞数目与对照组比较差异无显著性(P>0.05)。TM CATG脑内注射后Caspase-3蛋白表达和凋亡细胞数目与对照组比较差异均无显著性(P>0.05)。结论TM通过蛋白酶激活受体-1(protease activated receptor-1,PAR-1)激活Caspase-3,诱导细胞凋亡。

A study on effect of thrombin on apoptosis after intracerebral injection in rats and its mechanism

Objective To explore the effect of thrombin(TM) on caspase-3 protein expression and apoptosis after intracerebral injection in rats.Methods TM,TM CATG or TM DEVD-fmk was stereotaxically injected into right caudate nucleus in rats.Caspase-3 protein expression determined by Western-blot method.Apoptosis of cells was measured by TUNEL method.Results Caspase-3 protein expression was increased at 6h after TM intracerebral injection (P<0.05),peaked at 24h(P<0.01),and then declined.Cells of apoptosis increased at 24h after TM intracerebral injection(P<0.05),peaked at 48h(P<0.01),and then declined.Cells of apoptosis had no significant difference as compared with control group after TM DEVD-fmk intracerebral injection.Caspase-3 protein expression and cells of apoptosis had no significant difference as compared with control group after TM CATG intracerebral injection.Conclusion Thrombin activates caspase-3 by PAR-1 and then induces apoptosis.