AIM: To study the function and mechanism of the NgR-Rhoa-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 50mg/kg wight, after that the blood sugar value was greater than 16.7mmol/L as DM model, then randomly divided into 3 groups, 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 NgR-siRNA virus 10μL(siRNA group), NgR-siRNA virus diluted 10μL(DM group), NgR-siRNA virus-negative-control solution 10μL(siRNA blank group), NgR-siRNA virus diluted 10μL(normal control group), and fed normally. During that time, some life indexes like blood glucose, body mass, etc. were measured and recorded. After 12wk, 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.