The Role of Nogo Receptor on the Apoptosis of Retinal Ganglion Cells in Diabetic Rats / 天津医药

ABSTRACT

Objective To investigate the effect of Nogo receptor on the apoptosis of retinal ganglion cell (RGC) in di-abetic rats, and the potential mechanism thereof. Methods Thirty diabetic model rats were induced by intraperitoneal ad-ministration of streptozotocin. Model rats were randomly divided into control group, diabetes mellitus (DM) group, siNgR group and siRNA control group (n=10 for each group). Diabetic rats in siNgR group were intravitreally administrated with No-go receptor antisense nucleotide. Diabetic rats in siRNA control group were intravitreally administrated with negative nucleo-tide. One month after diabetes onset, colocalization of Nogo receptor and Brn3a (marker of RGC) was observed by immunohis-tochemistry. The apoptosis of RGC was detected by TUNEL staining. The level of retinal malondialdehyde (MDA) was ob-served with kit, and the expressions of Nogo receptor and caspase-3 were detected with Western blot assay. Results It was found that the Nogo receptor was highly expressed in RGC. The levels of retinal MDA were (3.68±0.47), (8.07±1.24), (7.54± 1.53) and (5.12 ± 0.62) μmol/g protein for control group, DM group, siRNA control group and siNgR group. The apoptotic rates of RGC were (5.1 ± 0.2)%, (49.3 ± 2.7)%, (45.6 ± 1.8)%and (12.4 ± 0.6)%respectively. The expressions of Nogo receptor were (0.18 ± 0.07)%, (0.45 ± 0.12)%, (0.40 ± 0.09)%and (0.16 ± 0.09)%. The expressions of caspase-3 were (0.16 ± 0.05)%, (0.40±0.18)%, (0.42±0.12)%and (0.17±0.08)%. Compared with control group, there was significant increase in apoptosis of RGC, significantly up-regulated expressions in Nogo receptor and caspase-3, and significantly increased level of MDA in DM group and siRNA control group(P<0.05). Compared with DM group, there were decreased apoptotic rate of RGC, de-creased expressions of Nogo receptor and caspase-3, and decreased level of retinal MDA in siNgR group (P<0.05). Conclu-sion The increased level of Nogo receptor induces oxidative stress and up-regulation of caspase-3 in diabetic retina, play-ing an important role in the apoptosis of RGC.