核运输因子2在糖尿病大鼠视网膜的时空表达及其意义

Temporal and spatial expression of NTF2 in retina of diabetic rats

目的:探讨糖尿病大鼠视网膜中核运输因子2(NTF2)的时空表达变化及意义。方法:伊凡思蓝(EB)灌注铺片观察糖尿病大鼠视网膜血管分布和形态。逆转录-聚合酶链式反应(RT-PCR)检测与糖尿病大鼠不同时点鼠龄匹配的对照组(N2w,N1m,N3m,N6m)和糖尿病成模后2周、1月、3月、6月(D2w,D1m,D3m,D6m)大鼠视网膜中NTF2、血管内皮生长因子(VEGF)mRNA的表达。免疫组化法检测NTF2蛋白在视网膜中的表达和分布位置。结果:正常组大鼠可见在低背景荧光下视网膜血管对EB有很好的屏障作用,成模1月后糖尿病大鼠视网膜血管仅见背景荧光增强,成模3月后血管出现异常节段性扩张,局部血管周围EB渗漏。与糖尿病大鼠年龄匹配的正常大鼠视网膜NTF2和VEGF并未随时间延长而变化,mRNA表达稳定。糖尿病成模2周后开始,NTF2mRNA有轻度增高,并随病程的延长保持较高水平,病程达6个月时,NTF2表达开始回落,与正常大鼠基本一致。NTF2蛋白在正常大鼠及糖尿病大鼠视网膜中免疫组化均可以检出,主要分布在视网膜内层,以节细胞层、内核层为主。结论:NTF2mRNA水平在糖尿病大鼠视网膜中升高,主要分布在视网膜内层。NTF2很可能在糖尿病视网膜病变中起着一定的调控作用,其作用途径及机制可能与VEGF的作用通路有一定的联系。

AIM ： To detect the expression and location of nuclear transport factor 2 （NTF2） in rat retina with diabetics. METHODS ： The retinal vasculature was observed by Evans blue perfusion. The mRNA expression of NTF2 and vascular endothelial growth factor （VEGF） was determined by reverse transcriptional polymerase chain reaction （ RT - PCR） in the retina from the control rats of 2 - week - old, 1 - month - old, 3 - months - old and 6 - months - old （ N2w, N1m ,N3m ,N6m） or in the retina from the rats of 2 weeks, 1 month, 3 months and 6 months after diabetics （D2w,D1m ,D3m, D6m ）. The protein expression and location of NTF2 were observed by immunohistochemical method. RESULTS ： The resuits of Evans blue perfusion were obtained in normal retinal vessels without leakage and with a very low level of background fluorescence. The stained vessels of diabetic retina showed increased fluorescence, indicating the damage of retina - blood barrier. The mRNA expression of VEGF was up - regulated after the onset of diabetic retina. The mRNA expression of NTF2 was stable in control retina, but increased in the retina of rats 2 weeks after diabetics. The expression of NTF2 was correlated with the up - regulation of VEGF. There was a descent tendency of NTF2 expression in the retina of the rats 6 months after diabetics. NTF2 protein expression was observed in the inner layers of retina in normal control rats and diabetic rats. CONCLUSION： The location of NTF2 expression is in the inner layer of retina, indicating that NTF2 gene plays an important role in maintaining the functions of vessels and nerve tissues. The expression of NTF2 and VEGF shows contradictory in the retina of 6 month diabetic rats, indicating the different effects of these molecules on the development of diabetic retina. NTF2 may play an important role in diabetic retinopathy.