缺血预处理对鼠肝细胞凋亡及调控基因(bcl-2,Fas)蛋白表达的影响

Effect of ischemic preconditioning on the apoptosis of hepatocytes and expression of regulating gene (bcl-2,Fas protiens) in rats

目的 观察鼠肝缺血再灌注损伤对肝细胞凋亡 ,以及缺血预处理对缺血再灌注损伤引起的肝细胞凋亡以及对其调控基因 (bcl 2 ,Fas)蛋白表达的影响。方法 Wistar大鼠分为假手术 (SO)组、缺血再灌注 (IR )组、缺血预处理 (IP)组 ,后 2组中分为 3个亚组 (IR1,2 ,3 ,IP1,2 ,3)。缺血均为 30min。缺血预处理为缺血前采用 5min缺血及 5min再灌。分别于再灌注1 5 ,3 ,4 5h后处死动物采取肝脏标本 ,SO组于术后 3 5h采取肝标本。检测细胞凋亡及bcl 2 ,Fas蛋白表达水平。结果 IR2 组和IP2 组与SO组比较细胞凋亡指数 (AI)显著性增加 (P<0 .0 1) ,IP组较IR组细胞AI显著性降低 (P <0 .0 5 )。电镜示凋亡细胞 ,但IP组较IR组的细胞器特别是线粒体损伤要轻。bcl 2蛋白表达 :IP组较IR组及SO组显著性增加 (P <0 .0 5 ) ,IR组与SO组无差异 (P >0 .0 5 )。Fas蛋白表达 :IR2 组和IP2 组较SO显著性增高 (P <0 .0 5 ) ,IP组与IR组比较无显著性差异 (P >0 .0 5 )。结论 IR损伤可能通过激活Fas蛋白的表达而促发肝细胞凋亡 ;IP可能通过激活bcl

Objective To explore whether hepatocellular ischemia reperfusion (IR) injury elicites the apoptosis of hepatocytes or ischemic preconditioning (IP) reduces the apoptosis (AP) of hepatocytes due to IR injury in the rat, and the effect of IP on AP regulating genes (bcl 2、Fas) protein expresssion. Methods Wistar rats were randomly divided into sham operation (SO) group, IR group and IP group. The latter two groups were futher divided into 3 subgroups respectively and subjected to 30 minutes of ischemia. IP was achieved by ischemia for 5 minutes, followed by reperfusion for 5 minutes before continuous block of the liver influe. The rats were killed after reperfusion for 1.5, 3 and 4.5 hours respectively, then liver tissues were sampled to examine the apoptosis and bcl 2 and Fas proteins. In SO group the rats were killed 3.5 hours after the operation and the liver tissues were sampled. Results Apotosis index of hepotocytes significantly in creased in IR groups compared with that in IP groups (P<0.05), and was significantly elevated in IR 2 group and IP 2 group than that in SO group (P<0.01). Electron microscope displayed apoptosis of hepatocytes and damage of organelles which was milder especial the mitochondrion in IP group than that in IR group. The expression of bcl 2 protein was significantly increased in IP group than that in both IR group and so group (P<0.05), the difference of which was no sigificant between IR group and SO group (P>0.05). Expression of Fas protein was significantly increased in IR group and IP group than that in SO group (P<0.01) while there was no significant difference between IP groups and IR groups (P>0.05). Conclusions This study shows that: (1) IR injury may activate the apoptosis of hepatocytes by increasing Fas gene expression. (2) IP may decrease the apoptosis of hepatocytes by increasing bcl 2 gene expression.