挫伤性视网膜病变中光感受器细胞凋亡与相关基因表达的研究

Expression of apoptosis-related genes and photoreceptor cell apoptosis in contusion injury of the rat retina

目的探讨挫伤性视网膜病变中Bax、Bcl-2表达与光感受器细胞凋亡的关系。方法自由落体法制作视网膜挫伤模型,行HE染色观察大鼠视网膜组织的病变情况;末端脱氧核酸转移酶介导的脱氧三磷酸尿苷缺口末端标记(TUNEL)法检测感光细胞凋亡情况;PV免疫组织化学法检测视网膜组织中Bax、Bcl-2的表达。结果TUNEL染色显示挫伤后3d组视网膜内可见较多阳性表达的细胞,分布在外核层。余实验组未测到阳性着色细胞。Bax在挫伤后4h即有表达,随时间延长表达逐渐增加,至挫伤后3d达高峰,至7d、14d组表达阴性。Bcl-2的表达在各组均为阴性。结论细胞凋亡是挫伤性视网膜病变的重要机制之一,Bcl-2/Bax相对比值改变可能对细胞凋亡的发生起一定的诱导作用。

Objective To explore the relationship between the expression of Bax, Bcl -2 and photoreceptor cell apoptosis in contusion injury of the rat retina. Methods The animal model of retinal injury was created by a free falling iron bar hitting the corne a. The morphologic changes of retina were observed by HE staining. Terminal dcoxynucleotiyl transferase - mediated dUTP - biotin nickend labeling（TUNEL） technique was used to assess apoptosis. The expressions of Bax, Bcl -2 were determined by PV immunohi stochemistry. Results There was a number of TUNEL positive apoptotic photoreceptor cells at the time of 3 d after contu- sion, while TUNEL positive photoreceptor cells could not be seen at other groups. Bax was expressed negatively in the groups of control, sham and 1 h after ocular contusion. It was weakly found in the 4 h after contusion,the expression was clear 1 d, at a peak 3 d, then disappeared at 7 d, 14 d. The expression of Bcl - 2 were negative in every group. Conclusions Apoptosis is an important mechanism of contusive damage to retina. The change of relative ratio of Bcl-2/ Bax plays an inducible role on cell apoptosis.