白藜芦醇对青光眼大鼠视神经损伤的保护作用及其机制

目的:分析白藜芦醇对青光眼大鼠视神经的保护作用及对磷脂酰肌醇3激酶(PI3K)/蛋白激酶B(Akt)信号通路及其相关因子的影响。方法:SPF级SD大鼠以烧灼巩膜表面静脉法制作右眼青光眼模型,建模成功后以不同剂量(10、20、40mg/kg腹腔注射)白藜芦醇干预,末次给药后2h检测各组大鼠眼压,进行视网膜铺片观察视网膜神经节细胞(RGC)存活情况,采用实时荧光定量PCR及Western blot法检测视网膜PI3K、Akt、碱性成纤维细胞生长因子(bFGF)、脑源性神经营养因子(BDNF)mRNA及蛋白表达情况。结果:模型组眼压(30.25±4.25mmHg)高于低剂量组(26.30±4.05mmHg)、中剂量组(22.31±3.68mmHg)和高剂量组(18.32±3.21mmHg),模型组RGC标识率(48.25%±4.50%)低于低剂量组(56.32%±5.05%)、中剂量组(66.03%±6.68%)和高剂量组(78.56%±7.82%)(均P<0.05),且低、中、高剂量组眼压呈剂量依赖性下降,RGC标识率呈剂量依赖性升高。模型组p-PI3K/PI3K、p-Akt/Akt蛋白比值及bFGF、BDNF mRNA和蛋白相对表达量低于低剂量组、中剂量组和高剂量组(均P<0.05),且低剂量组、中剂量组、高剂量组呈剂量依赖性升高。结论:白藜芦醇能抑制青光眼大鼠RGC的凋亡,减轻视神经损伤,其机制可能与上调PI3K/Akt信号通路中相关蛋白的磷酸化及视神经保护作用因子基因与蛋白的表达有关。

Protective effect and mechanism of resveratrol on optic nerve injury in glaucoma rats

AIM: To analyze the protective effect of resveratrol on the optic nerve of glaucoma rats and its effect on the phosphatidylinositol 3 kinase(PI3K)/protein kinase B(Akt)signal pathway and its related factors.

METHODS: SPF grade SD rats were used to cauterize the scleral surface veins to make a right eye glaucoma model. After successful modeling, different doses(10, 20, 40 mg/kg intraperitoneal injection)of resveratrol were used to intervene. Intraocular pressure was measured 2h after the last administration, and retinal slices were made to observe the survival of retinal ganglion cells(RGC). Retinal plaque to observe the survival of retinal ganglion cells(RGC). Real-time fluorescence quantitative PCR and Western blot were used to detect the mRNA and protein expression of retinal PI3K, Akt, basic fibroblast growth factor(bFGF), and brain-derived neurotrophic factor(BDNF).

RESULTS: The intraocular pressure(30.25±4.25)mmHg in the model group was higher than that in the low-dose group(26.30±4.05)mmHg, the middle dose group(22.31±3.68)mmHg and the high dose group(18.32±3.21)mmHg, and the model group RGC labeling rate(48.25±4.50)% was lower than the low dose group(56.32±5.05)%, middle dose group(66.03±6.68)% and high dose group(78.56±7.82)%(P<0.05). The intraocular pressure in the low, middle and high dose groups decreased in a dose-dependent manner, and the RGC labeling rate increased in a dose-dependent manner(P<0.05). The p-PI3K/PI3K, p-Akt/Akt protein ratio, bFGF, BDNF mRNA and protein relative expression in the model group were lower than those in the low dose group, middle dose group, and high dose group(P<0.05), and the low-dose group, middle dose group and high-dose group increased in a dose-dependent manner.

CONCLUSION: Resveratrol can inhibit the apoptosis of RGC in glaucoma rats and reduce optic nerve damage, which may be related to the up regulation expression of phosphorylated of related proteins in PI3K/Akt signal pathway and the expression of protective gene and protein of optic nerve.