放射性肺损伤大鼠肺组织Bcl-2和Bax表达变化及其意义的探讨

Expressions and significance of apoptosis-related proteins Bcl-2 and Bax in radiation-induced lung injury in rats

目的:探讨凋亡相关蛋白Bcl-2和Bax在放射性肺损伤大鼠肺组织中的变化及意义。方法:Wistar大鼠30只随机分为正常对照组(N)、照射组(d1、d7、d14、d28和d56),每组5只。在照射后d1、d7、d14、d28和d56获取标本,采用透射电镜、免疫组化和流式细胞等技术,观察放射性肺损伤大鼠肺组织细胞凋亡的变化及Bcl-2和Bax的表达。结果:放射性肺损伤大鼠肺上皮细胞凋亡增加,照射组Bax在上皮细胞的表达及Bcl-2在间质细胞的表达高于对照组。照射后d7、d14、d28和d56上皮细胞Bax的表达高于对照组,χ2=24.847,P<0.01;照射后d14和d28间质细胞Bcl-2的表达高于对照组,χ2=20.930,P<0.01。而Bcl-2在上皮细胞的表达及Bax在间质细胞的表达无明显变化(P>0.05)。表明上皮细胞的Bax/Bcl-2比值上升,而间质细胞的Bax/Bcl-2比值下降。结论:细胞凋亡及凋亡相关蛋白Bcl-2和Bax的不平衡表达在放射性肺损伤的发病过程中可能起了重要作用。

OBJECTIVE：To investigate the effects of apoptosis-related proteins bcl-2 and bax in radiation-induced lung injury in rats.METHODS：Wistar rats were randomly divided into 6 groups,including control （N） and radiation groups （d1,d7,d14,d28 and d56）.After radiation,the rats were killed on （d1,d7,d14,d28 and d56）.HE staining,electron microscopy,immunohistochemisty and flow cytometry methods were used.RESULTS：The appearance of apoptosis increased in lung epithelial cells.The expressions of Bcl-2 in mesenchymal cells and Bax in epithelial cells were higher in the radiation groups than those in the control group.The expression of Bax in epithelial cells was higher in the radiation group than in the control group on d7,d14,d28 and d56 （χ2=24.847,P0.01）.The expression of Bcl-2 in mesenchymal cells was higher in the radiation group than that in the control group on d14 and d28 （χ2=20.930,P0.01）.However,the expression of Bcl-2 in epithelial cells and Bax in the mesenchymal cells did not show the significant difference among radiation groups （P0.05）.The expression of Bcl-2 significantly increased and Bax decreases in mesenchymal cells,whereas the expression of Bcl-2 significantly decreased and Bax increases in epithelial cells.CONCLUSION：These changes suggest that the unbalance between apoptosis promoting factor and apoptosis inhibition factor may play a very important role in the development of radiation-induced lung injury.