9.5蛋白基因产物表达与青光眼性视神经病变关系

CORRELATION BETWEEN PGP9.5 EXPRESSION AND OPTIC NEUROPATHY IN GLAUCOMA

目的检测视神经横断大鼠视网膜中9.5蛋白基因产物(PGP9.5)的表达,探讨PGP9.5在青光眼视神经病变中的作用。方法 Wistar大鼠30只,随机分为A、B两组,A组15只大鼠用于免疫组织化学染色,B组15只大鼠用于逆转录聚合酶链反应(RT-PCR)。每组根据视神经横断的时间不同又分3组,每组5只大鼠,左眼为对照眼,右眼为视神经横断侧(实验眼),分别于视神经横断后第1、3、5天采用RT-PCR的方法检测两侧视网膜中PGP9.5mRNA的表达,并对不同时间点视网膜组织神经元行免疫组织化学染色及光镜观察。结果光镜下,视神经横断后第1天,视网膜神经节细胞胞浆疏松,细胞核肿胀,核周出现空隙;视神经横断后第3天,细胞核进一步增大,空隙变大;视神经横断后第5天,细胞核形态不规则,部分出现核碎裂。免疫组织化学染色显示,大鼠对照眼视网膜未见有PGP9.5表达。实验眼视神经横断后第1、3、5天,PGP9.5染色明显增强,与对照眼比较,差异有显著性(F=237.068,P<0.01)。RT-PCR检测结果显示,视神经横断后第1天,视网膜组织中PGP9.5mRNA的表达升高,在视神经横断后第3天时表达最强,至第5天时表达水平下降,但仍较对照眼明显增高,差异有显著性(F=47.422,P<0.01)。结论视神经横断大鼠视网膜组织中PGP9.5蛋白及mRNA表达均明显增高,与视网膜神经节细胞的凋亡密切相关,提示PGP9.5可能参与了青光眼视神经病变的发生与发展。

Objective To detect the expression of PGP9.5 in models of optic-nerve-transection （ONT） rat and explore the role of PGP9.5 in optic neuropathy in glaucoma. Methods Thirty Wistar rats were evenly randomized to group A and group B. The rats in group A were for immunohistostaining, and those in group B were for semi-quantitative reverse transcription poly- merase chain reaction （RT-PCR）. The rats in each group were subdivided into three groups with five rats in each subgroup accor- ding to the time of transection of the optic-nerve, the left eye was served as the control eye, and the right one was the ONT site （experimental eye）. The expression of PGP9.5 mRNA in retina 1,3 and 5 days after ONT-was detected in both eyes using RT PCR and the neurons of retina in different time points were observed applying immunohistostaining and light microscope. Results The findings under light microscope were： on the first day after ONT, the cytoplasm of retinal ganglion cell became puff and the nucleus became swelling and cellule appeared around the nucleus; on the third day after ONT, the cell nucleus further enlarged with space greatened; on the fifth day, the shape of the nucleus became irregular, and karyorrhexis could be seen. Immunohis tostaining revealed that in the control eyes, no PGP9.5 expressions were seen. In experimental eyes, on days 1,3 and 5 after ONT, the staining of PGP9.5 was obviously enhanced, the difference was significant versus the control eyes （F=237.068,P〈0.01）. The results of RT-PCR detection were as follows： on the first day after ONT, the expression of PGPg.5 mRNA in retinal tissue was heightened, the strongest was noted on the third day, and on the fifth day, the expression declined, but still much higher than that in the control eyes, the difference was significant （F = 47. 422, P〈 0.0l）. Conclusion The expression of PGPg. 5 protein and mRNA in retinal tissue of optic-nerve-transection rats is significantly increased and closely associated with the apoptosis of retinal ganglion cells, which is suggestive of PGP9.5 may involve in the occurrence and development of glaucomatous optic neuropathy.