维生素B12对糖尿病大鼠视网膜神经细胞凋亡的影响

发布时间：2018-05-14 12:38

本文选题：维生素B + 糖尿病视网膜病变　；参考：《眼科新进展》2017年12期

【摘要】：目的观察维生素B12对糖尿病大鼠视网膜神经细胞凋亡的影响并分析其作用机制。方法取清洁级SD大鼠36只,随机分为正常对照组(NC组)、糖尿病模型组(DM组)、维生素B12治疗组(Vit B12组),每组12只。DM组和Vit B12组腹腔注射链脲佐菌素建立糖尿病大鼠模型。确定造模成功后,每天对Vit B12组进行维生素B12(100μg·kg~(-1))灌胃,持续8周,NC组和DM组用同体积生理盐水替代。停止灌胃2周后,于第10周末将所有大鼠处死,取颈静脉血,用于检测血清中丙二醛含量及超氧化物歧化酶的活性;取视网膜组织,用于制备视网膜石蜡切片,采用TUNEL法进行视网膜凋亡细胞原位标记,计算视网膜神经节细胞凋亡指数(apoptosis index,AI);采用免疫组织化学法检测视网膜组织Caspase-3蛋白的表达。结果三组大鼠血清丙二醛含量比较,差异有统计学意义(F=471.061,P=0.000),DM组、Vit B12组丙二醛含量高于NC组(均为P0.01),DM组高于VitB 12组(P0.01);三组间血清超氧化物歧化酶活性差异有统计学意义(F=356.923,P=0.000),DM组、VitB 12组超氧化物歧化酶活性低于NC组(均为P0.01),DM组低于VitB 12组(P0.01)。三组大鼠视网膜神经节细胞层、内核层和外核层均可见凋亡细胞,DM组和VitB 12组凋亡细胞数较NC组明显增多,VitB 12组凋亡细胞数较DM组有不同程度减少。三组视网膜神经节细胞AI值比较差异有统计学意义(F=14.926,P=0.000),DM组、VitB 12组AI值均高于NC组(均为P0.01),DM组AI值高于VitB 12组(P0.05)。显微镜观察发现三组大鼠视网膜神经节细胞层、内核层和外核层均可见Caspase-3蛋白表达,DM组和VitB 12组Caspase-3蛋白表达均较NC组明显增多,VitB 12组Caspase-3蛋白表达较DM组明显减少。三组视网膜Caspase-3光密度值比较差异有统计学意义(F=77.896,P=0.000),DM组、VitB 12组视网膜Caspase-3光密度值均高于NC组(均为P0.01),DM组高于VitB 12组(P0.01)。结论维生素B12对糖尿病视网膜神经细胞有一定的保护作用,其机制可能是维生素B12通过抗氧化作用抑制Caspase-3的表达从而抑制神经细胞的凋亡。
[Abstract]:Objective to observe the effect of vitamin B 12 on apoptosis of retinal nerve cells in diabetic rats and analyze its mechanism. Methods Thirty-six SD rats of clean grade were randomly divided into normal control group (NC group), diabetic model group (DM group), vitamin B12 treatment group (Vit B12) group (n = 12) and streptozotocin (Vit B 12) group (n = 12). The diabetic rats were induced by intraperitoneal injection of streptozotocin (STZ) in each group. After the model was established successfully, Vit B12 group was given vitamin B12 100 渭 g / kg / day intragastric perfusion for 8 weeks, the NC group and the DM group were replaced by normal saline of the same volume. After two weeks of gastric perfusion, all the rats were killed at the end of the 10th week, the jugular vein blood was taken to detect the malondialdehyde content in serum and the activity of superoxide dismutase, and the retina tissue was taken for the preparation of paraffin sections of the retina. The apoptosis index of retinal ganglion cells was calculated by TUNEL method, and the expression of Caspase-3 protein in retinal tissue was detected by immunohistochemical method. Results the content of malondialdehyde in serum of the three groups was compared. The content of malondialdehyde (MDA) in Vit B12 group was higher than that in NC group (P 0.01) and the activity of serum superoxide dismutase in DM group was higher than that in VitB 12 group (P 0.01) and the activity of serum superoxide dismutase in DM group was lower than that in Vit B12 group. It was lower in NC group (P 0.01) than in VitB 12 group (P 0.01). The number of apoptotic cells in the retinal ganglion cell layer, nuclear layer and outer nuclear layer of the three groups were significantly increased in DM group and VitB 12 group compared with NC group. The number of apoptotic cells in Vit B12 group was lower than that in DM group. The AI of retinal ganglion cells in DM group was significantly higher than that in NC group (P 0.01) and the AI value of DM group was higher than that of VitB group (P 0.05). Microscopic observation showed that the expression of Caspase-3 protein in retinal ganglion cell layer, nuclear layer and outer nuclear layer was significantly increased in DM group and VitB 12 group compared with NC group. The expression of Caspase-3 protein in Vit B12 group was significantly lower than that in DM group. There were significant differences in Caspase-3 optical density between the three groups. The Caspase-3 optical density of retina in Vit B12 group was significantly higher than that in NC group (P 0.01) and that in VitB 12 group was higher than that in VitB 12 group (P 0.01). Conclusion Vitamin B12 has a protective effect on diabetic retinal nerve cells, and its mechanism may be that vitamin B12 inhibits the expression of Caspase-3 and thus inhibits neuronal apoptosis through antioxidant action.
【作者单位】：锦州医科大学附属第一医院眼科;
【基金】：辽宁省科技厅联合基金项目(编号:2015020351)~~
【分类号】：R587.2;R774.1

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