Effect Of Nerve Growth Factor On The Retinal Ganglion Cells And The Expression Of Synaptophysin In Diabetic Rat

ObjectiveTo investigate the effect and the mechanism of nerve growth factors?NGF?on the retinal ganglion cells?RGC?and the expression of synaptophysin?SYN?in diabetic rat.MethodsClean male SD rats were randomly divided into CONT group,DM group and NGF group,8 rats in each group.In the latter two groups,the DM model was induced by streptozotocin?STZ?.The NGF group was given intraperitoneal injection?IP?of mNGF(800U·kg^-1)was in successful DM model,once a day.CONT group and DM group were given normal saline.After 12 weeks,the body weight,blood glucose,MDA content and SOD activity were evaluated.The RGC density of was detected by HE staining.The expression of synaptophysin?SYN?was calculated by Immunofluorescence.The expression of SYN and Caspase-3 were detected by Western blot.ResultsBody weight and blood glucose test results:there was no significant change in basal weight and blood glucose between the three groups?P>0.05?.Compared with CONT group,the weight of rats in group DM and group NGF decreased significantly after 12 weeks?P<0.01?,and blood glucose increased significantly?P<0.01?.MDA content and SOD activity test results:compared with the CONT group,the content of MDA in the DM group increased significantly?P<0.01?,compared with the DM group,the NGF group was significantly decreased?P<0.01?.Compared with CONT group,the activity of SOD in DM group was significantly decreased?P<0.01?,compared with DM group,the NGF group was significantly increased?P<0.01?.The results of HE staining showed that the number of RGC in CONT group was more and the structure was clear.DM group RGC structure disorder,a small number,compared with the CONT group density decreased?P<0.01?.Compared with DM group,the RGC density of NGF group increased significantly?P<0.01?.SYN immunofluorescence results:SYN in the inner plexiform layer and outer plexiform layer of the retina,compared with the CONT group,the fluorescence intensity of DM group decreased significantly?P<0.01?,compared with DM group,the fluorescence intensity of NGF group was significantly higher?P<0.01?.Western blot test results:compared with CONT group,the expression of SYN in group DM was significantly reduced?P<0.01?,with the DM group,the expression of SYN was significantly increased in NGF group?P<0.01?.Compared with the CONT group,the expression of Caspase-3 in the DM group was significantly increased?P<0.01?,compared with the DM group,the NGF group was significantly reduced?P<0.01?.ConclusionNGF can inhibit the apoptosis of RGC,recovery the number of synapses and protect the damaged RGC by reducing the oxidative stress in diabetic retina.