缺血预处理对胆管上皮细胞凋亡及bcl-2/Fas蛋白表达的影响

Effect of ischemic preconditioning on the apoptosis and expression of bcl-2/Fas proteins on intra-hepatic cholangiocyte

目的观察缺血预处理对缺血再灌注损伤引起的胆管上皮细胞凋亡(AI)以及对调控基因(bcl-2,Fas)蛋白表达的影响。方法SD大鼠36只分为假手术(SO)组、缺血再灌注(IR)组、缺血预处理(IP)组。热缺血时间为30 min。缺血预处理为缺血前采用5 min缺血及5 min×2次再灌注。分别于再灌注12 h后处死动物取肝脏标本。检测肝内胆管上皮细胞凋亡及bcl-2/Fas蛋白表达水平。结果凋亡细胞主要见于肝内大胆管,SO组凋亡的胆管上皮细胞罕见,IR和IP组与SO组比较,胆管上皮细胞AI有显著性增加(P<0.01,P<0.05)。IP组与IR组比较,胆管上皮细胞AI有显著性降低(P<0.05)。肝内大胆管bcl-2蛋白阳性表达:IP组bcl-2蛋白阳性表达较SO组和IR组差异均具有显著性意义(P<0.01,P<0.05)。Fas蛋白阳性表达:IR组与SO组比较,Fas蛋白阳性表达差异有显著性意义(P<0.05)。IP组与IR组间相比差异无显著性意义(P>0.05)。结论IR诱导Fas蛋白的表达促进肝内胆管上皮细胞发生凋亡。IP通过上调调控基因bcl-2蛋白的表达抑制胆管上皮细胞的凋亡,与Fas蛋白表达关系不明显。

Objective To abserve the effect of ischemic preconditioning on the apoptosis of intrahepatic cholangiocyte and expression of regulating genes （bcl-2, Fas Proteins ） on bileducts. Methods SD rats were randomly divided into sham operation （SO） group, IR group and IP group. The latter two groups were subjected to 30 minutes of ischemia on liver. IP group livers were achieved with ischemia for 5 minutes and then followed by twice reperfusion for 5 minutes before the liver reinflue. Twelve hours after repeffusion, the rats were killed and liver tissue were sampled to observe the apoptosis and expression of be1-2 and Fas proteins on intrahepatic bileduct.Results Apeptosis was mainly observed in large bile ducts （ 〉 20 tin1）. Compared with SO group in which nearly no apoptosis was found, there were significant difference of AI in IR group and IP group （P 〈 0.01, P 〈 0.05）. At the same time, AI decreased markedly in IP group comparing with IR group （P 〈0.05）. Positive rate of be1-2 protein on large bile duct： there was a significant difference in IP group while comparing with SO group （ P 〈0.01 ） andIR group （ P 〈0.05）. Positive rate of Fas protein： compared with SO group, a high positive rate of Fas protein was found on large bile duct in IR group （ P 〈 0.05） ; no significant difference was found between IR group and IP group. Conclusion This study shows that： IR injury may activate the apoptosis of intra-hepatic cholangiocyte by increasing Fas gene expression; IP may protect bile duct from IR injury by elevating the expression of bel- 2 protein on large bile duct.