Abstract: Objective To investigate effects and potential mechanisms of Nogo receptor on the apoptosis of retinal ganglion cell (RGC) in diabetic rats. Methods Diabetic rats were induced by intraperitoneally administration of streptozotocin. Studies were conducted with control group, diabetes mellitus (DM) group, siNgR group and siRNA control group (n=10/group). Diabetic rats in siNgR group were intravitreally administrated with anti-Nogo receptor nucleotide. While, diabetic rats in siRNA control group were intravitreally administrated with negative nucleotide. One month after diabetes onset, colocalization of Nogo receptor and Brn3a (marker of RGC) were observed with immunohistochemistry, TUNEL staining was conducted to reveal apoptosis of RGC, the level of retinal malondialdehyde (MDA) were observed with kit, and the expression of Nogo receptor and caspase-3 were detected with Western blot. Results Nogo receptor is highly expressed in RGC. The level of retinal MDA in control, DM, siNgR and siRNA control groups were (3.68±0.47), (8.07±1.24), (7.54±1.53) and (5.12±0.62) mol/g prot respectively. The number of TUNEL-positive RGC, expression of retinal Nogo receptor and caspase-3, and the level of retinal MDA were significantly increased in DM and siNgR groups, compared with control group (P<0.05). While, these alterations in DM group were attenuated in siNgR group (P<0.05). Conclusion Nogo receptor induces oxidative stress and up-regulation of caspase-3 in diabetic retina, playing an important role in the apoptosis of RGC.

Key words: diabetes mellitus, retinal ganglion cell, nogo receptor, apoptosis