细胞凋亡和Bcl-2、Bax基因在兔肺缺血再灌注损伤中的作用

Role of apoptosis and Bcl-2,Bax gene in rabbits with lung ischemia reperfusion injury

目的:探讨细胞凋亡在兔肺缺血再灌注损伤中的作用以及Bcl-2和Bax基因的调控。方法:健康日本大耳白兔48只,随机分为对照组与肺缺血再灌注损伤1 h、3 h和5 h组。复制在体肺缺血再灌注损伤模型。采用TUNEL法观测肺组织细胞凋亡;予免疫组化及原位杂交技术检测肺组织细胞Bcl-2、Bax 蛋白和基因表达。结果:随着再灌注时间的延长,凋亡指数(AI)及Bax蛋白、BaxmRNA水平进行性升高;Bcl-2蛋白及Bcl-2mRNA先升高而后下降(均P<0．01)。凋亡指数(AI)与Bax蛋白及Bax mRNA 之间均呈显著正相关(r分别=0．926,0．933;均P<0．01),而与Bcl-2蛋白/Bax蛋白及Bcl-2mRNA/ BaxmRNA的比值呈显著负相关(r分别=-0．836,-0．879;均P<0．01)。结论:肺组织细胞凋亡参与了肺缺血再灌注损伤的发生,Bcl-2/Bax的比值下降是促进凋亡的重要因素。

Objective： To evaluate the effects of apoptosis and expression of apoptotic related genes on lung tissues of rabbits after lung ischemia reperfusion. Methods： Single lung in situ ischemia reperfusion animal model was used. 48 rabbits were randomly divided into four groups： control group（C）, ischemia reperfusion lh group（IR1h）, ischemia reperfusion 3h group （IR3h） and ischemia reperfusion 5h group （IR5h）. By using TUNEL, immunocytochemistry and in situ hybridization （ISH） techniques, apoptosis and Bcl-2, Bax mRNA and protein expression were studied in lung tissues of rabbits treating with lung ischemia reperfusion and in control subjects. Results Increasing of apoposis index（AI）and the expression of Bax gene were discovered during lung ischemia reperfusion injury in rabbits,and the expression of Bcl-2 was increased at the beginning, then declined. There was a significant positive correlation between AI and the expression of Bax （r=-0.926,0.933; P〈0.01,respectively）,and there was a significant negative correlation between AI and the ratio of Bcl-2 protein/Bax protein.Bcl-2 mRNA/BaxmRNA（r=-0.836,- 0.879; P〈 0.01,respectively）. Conclusion： Apoptosis participates in lung ischemia reperfusion injury. The ratio of Bcl-2/Bax declines gradually,which accelerates the occurrence of apoptosis.