NgR-Rhoa-Rock信号通路在早期糖尿病大鼠RGC凋亡中的作用

The role of NgR-Rhoa-Rock signal pathway in retinal ganglion cell apoptosis of early diabetic rats

目的:研究NgR-Rhoa-Rock信号通路在糖尿病(diabetes mellitus,DM)大鼠视网膜神经节细胞凋亡中的作用及机制。方法:健康SD大鼠,以50mg/kg体质量单次腹腔注射1%链脲佐菌素的方法处理,以血糖值大于16.7mmol/L定为糖尿病模型;然后随机分成3组,每组10只。另取10只健康SD大鼠作对照组。再依次对4组大鼠进行双侧眼球玻璃体腔内注射NgR小干扰病毒10μL(siRNA组)、NgR小干扰病毒稀释液10μL(DM组)、NgR小干扰病毒阴性对照液10μL(siRNA空白组)、NgR小干扰病毒稀释液10μL(正常对照组),正常喂养。期间对血糖、体质量等一些生命指标进行观查、测量并记录。12wk后,行视网膜Western blot检测NgR、Rhoa的表达,HE染色、TUNEL染色。结果:Western检测:与正常对照组相比,DM组和siRNA空白组中NgR、Rhoa表达明显增加(P<0.01),而siRNA组无明显变化(P>0.05);与DM组和siRNA空白组相比,siRNA组NgR、Rhoa表达明显下调。HE染色:与正常对照组相比,三组模型鼠均有不同程度节细胞排列紊乱、形态不规则、间距不一致;与DM组和siRNA空白组相比,siRNA组节细胞在排列顺序、外形大小等有一定程度改善。TUNEL染色:与正常对照组相比,三组模型鼠均有节细胞凋亡;与DM组和siRNA空白组相比,siRNA组凋亡细胞数量较少,细胞外形有明显改善。结论:DM时大鼠视网膜NgR、Rhoa表达上调,抑制NgRRhoa-Rock可以改善糖尿病视网膜神经节细胞的凋亡。

AIM： To study the function and mechanism of the NgRRhoa- Rock signal pathways which exists in the retinal ganglion cells apoptosis in diabetes mellitus（ DM） rats.METHODS： Some healthy SD rats were operated by means of single intraperitoneal injection of 1%streptozotocin based on the standard of 50 mg /kg wight,after that the blood sugar value was greater than16. 7mmol /L as DM model,then randomly divided into 3groups,each group was 10 rats. In addition to take 10 healthy SD rats as control group. Four groups of rats were bilaterally eyeball intravitreal injection in turn with NgRsiRNA virus 10μ L（ siRNA group）, NgR- siRNA virus diluted 10μ L（ DM group）,NgR-siRNA virus-negative-control solution 10μ L（ siRNA blank group）,NgR-siRNA virus diluted 10μ L（ normal control group）, and fed normally. During that time,some life indexes like blood glucose,body mass,etc. were measured and recorded.After 12 wk,the expression of NgR and Rhoa,HE staining,and TUNNEL staining were detected by Western blot analysis. RESULTS： Western blot analysis： compared with normal control group,the expression of NgR and Rhoa in DM group and siRNA blank group increased significantly（ P〈0.01）,while siRNA group was no significant change（ P〈0.05）; compared with DM group and siRNA blank group, the expression of those proteins significantly lowered in siRNA group. HE staining： compared with normal control group, some extent ganglion cells arranged disorder, irregular shape, spacing not consistent were all found in three groups of model rats;compared with DM group and siRNA blank group,there was some improvement in siRNA group of ganglion cells about the order and shape size. TUNEL staining：compared with normal control group,there were retinal ganglion cells apoptosis in all of three groups of model rats. Compared with DM group and siRNA blank group,the number of retinal ganglion cells apoptotic cells was less,and the shape of cells had improved significantly in siRNA group.CONCLUSION： In the DM phase,the expression of NgR and Rhoa were up- regulation,the condition of diabetic retinal ganglion cell apoptosis was improved after that the NgR-Rhoa-Rock signal pathways had been inhibited.