牡荆苷对大鼠视网膜缺血-再灌注损伤模型中神经节细胞的保护作用

目的:探讨牡荆苷对大鼠视网膜缺血-再灌注(RIR)引起的视网膜神经节细胞(RGCs)氧化应激损伤的保护作用及其可能的作用机制。方法:将60只SPF级雄性SD大鼠按照随机数字表法随机分为正常对照组、模型组和牡荆苷组，均以右眼为实验眼。模型组和牡荆苷组大鼠采用前房灌注方法建立RIR模型，牡荆苷组大鼠建模后每日按照25 mg...

Protective effect of vitexin on retinal ganglion cells in rat retinal ischemia-reperfusion injury model

Objective To explore the protective effect of vitexin on retinal ganglion stem cells(RGCs)from oxidative stress caused by retinal ischemia-reperfusion(RIR)in rats and its possible mechanism.Methods Sixty male SD rats were randomly divided into the model group,vitexin group and normal control group by random number table,with 20 rats in each group.The right eyes were taken as experimental eyes.Rats in the model group and the vitexin group were treated with anterior chamber perfusion to establish RIR models.Rats in the vitexin group were given intraperitoneal injection of vitexin at a dose of 25 mg/(kg·d)for 7 days.Rats in the model group were intraperitoneally injected with the same volume of normal saline.For the normal control group,the experimental eyes underwent anterior chamber puncture without increasing the intraocular pressure,and were intraperitoneally injected with the same volume of normal saline.On the 7th day following modeling,the rats were sacrificed by overdose anesthesia.Histopathology staining was used to detect the thickness of retina and the number of RGCs.Retrograde tracing with Fluoro-Gold was used to detect the density of RGCs.TUNEL staining was used to detect the apoptosis of RGCs.Colorimetric method was used to detected superoxidate dismutase(SOD)activity and concentration of malondialdehyde(MDA)and nitric oxide(NO).Western blot method was used to detect the relative expression levels of cytoplasmic Nrf2,HO-1,NQO1,nuclear Nrf2 proteins in rat retina.The use and care of animals followed the ARVO Statement.This study protocol was approved by the Experimental Animal Ethics Committee of Henan Eye Hospital(No.HNEECA-2019-04).Results The retinal thickness was(90.21±3.55)μm in the model group,which was significantly lower than(128.20±5.31)μm in the normal control group and(119.65±6.14)μm in the vitexin group,and the differences were statistically significant(both at P<0.05).The average density of RGCs was(1300.85±14.00)/mm²in the model group,which was significantly lower than(2330.12±15.05)/mm²in the normal control group and(1921.64±11.78)/mm²in the vitexin group,and the differences were statistically significant(both at P<0.05).The rate of TUNEL positive RGCs was(68.34±5.04)%in the model group,which was significantly higher than(3.01±0.18)%in the normal control group and(35.51±2.04)%in the vitexin group,and the differences were statistically significant(both at P<0.05).Compared with the normal control group and the vitexin group,the SOD activity in the retinal tissue of the rats was lower and the concentrations of MDA and NO were higher in the model group,and the differences were statistically significant(all at P<0.05).The expression level of cytoplasmic Nrf2 protein was the lowest in the vitexin group,then following the model group and the normal control group,and the relative expression levels of HO-1,NQO1 and nuclear Nrf2 protein were the highest in the vitexin group,then followed the model group and normal control group,and the differences were statistically significant(all at P<0.05).Conclusions Vitexin can reduce the apoptosis of RGCs and alleviate oxidative stress damage of retina in RIR rat model.This protective effect may be achieved by activating Nrf2-related signaling pathway.