Nogo受体对糖尿病大鼠视网膜神经节细胞凋亡的影响

目的 探讨Nogo受体对糖尿病大鼠视网膜神经节细胞凋亡的影响及机制。方法 SD大鼠腹腔注射链脲佐菌素诱导糖尿病模型，分为对照组，糖尿病组，siNgR组，siRNA空白组，每组10只。siNgR组糖尿病大鼠玻璃体内给予Nogo受体反义核苷酸序列；siRNA空白组糖尿病大鼠玻璃体内注射阴性核苷酸序列。1个月后，免疫荧光组化检测Nogo受体与视网膜神经节细胞（RGC）标志物Brn3a的共存；以TUNEL染色观察RGC凋亡；试剂盒检测视网膜丙二醛（MDA）含量；Western blot检测视网膜Nogo受体及半胱氨酸天冬氨酸蛋白酶3（caspase-3）表达。结果 Nogo受体大量表达于视网膜RGC内，对照组、糖尿病组、siRNA空白组及siNgR组MDA含量分别为（3.68±0.47）、（8.07±1.24）、（7.54±1.53）及（5.12±0.62）μmol/g 蛋白。与对照组相比，糖尿病组及siRNA空白组视网膜RGC凋亡明显，Nogo受体及caspase-3表达上调，MDA含量增加（P<0.05）。与糖尿病组相比siNgR组视网膜RGC凋亡减少、Nogo受体及caspase-3表达下调、MDA含量降低（P<0.05）。结论 Nogo受体表达上调参与了糖尿病视网膜RGC凋亡，其机制可能与Nogo受体上调caspase-3表达、诱发视网膜氧化应激有关。

Role of Nogo receptor on the apoptosis of retinal ganglion cell in diabetic rats

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.