Effect and mechanism of blueberry anthocyanin on oxidative damage of retinal ganglion cells in diabetic rats by reg-ulating Notch1/Hes-1 pathway
Objective To study the effect of blueberry anthocyanin(BA)on oxidative damage of retinal ganglion cells(RGC)in diabetic rats and its possible mechanism.Methods Fifty male SD rats were randomly divided into normal group(NC group,n=10)and modeling group.The modeling group was one-time injected with streptozotocin(STZ)of 50 mg/kg.After successful modeling,the rats were randomly divided into diabetic model group(DM group),blueberry anthocyanin group(BA group),DAPT group(Notch1 pathway inhibitor)and blueberry anthocyanin+DAPT group(BA+DAPT group),with 10 rats in each group.BA group was given 20 mg/kg BA by gavage every day,DAPT group was given 10 μmol/L DAPT intervention,BA+DAPT group was given 20 mg/kg BA by gavage+10 μmol/L DAPT intervention,NC group and DM group were given the same amount of 0.9％sodium chloride solution(normal saline)by gavage for 8 weeks.Twenty-four hours after the last admin-istration,the eyeballs of rats were removed,and the contents of reactive oxygen species(ROS),catalase(CAT),superoxide dismutase(SOD)and malondialdehyde(MDA)in retinal tissues of rats of each group were detected by enzyme-linked immunosor-bent assay(ELISA)kit.The hematoxylin-eosin(HE)staining was used to observe the pathological changes of retinal tissue in rats,and RGC count was performed.The expression of HO-1 and iNOS mRNA was detected by qRT-PCR.The expression of Notchl and Hes-1 protein was detected by Western blot.Results After modeling,FBG values in DM,BA,DAPT and BA+DAPT groups were all greater than 16.7 mmol/L.After BA intervention,FBG content in BA group and BA+DAPT group was sig-nificantly decreased,and in BA group was lower than that in BA+DAPT group(P＜0.05).ELISA results showed that,compared with NC group,the contents of ROS and MDA were increased in DM group,while the contents of CAT and SOD were decreased(P＜0.05).Compared with DM group,ROS and MDA levels in BA and BA+DAPT groups were decreased,while CAT and SOD levels were significantly increased(P＜0.05).The optical microscope observation results showed that the retinal structure of NC group was clear,and cell morphology was normal and orderly.In DM group,the retinal ganglion cell layer was disordered,the inner and outer nuclear layers were accompanied by edema,and retinal thickness became thinner.The structure of retinal layer in BA group was more orderly,and degree of edema and retinal thickness were improved compared with that in DM group.The retinal tissue in BA+DAPT group was improved compared with that in DM group,but retinal thickness was still thinner than that in BA group.RGC counting results showed that the numbers of RGC in DM group,BA group,DAPT group and BA+DAPT group were 7.35± 1.28,12.05±1.52,5.61±1.72 and 8.72±1.19,respectively,and they were significantly lower than that in NC group 16.63± 1.54,and the inter-group differences were statistically significant(F=88.905,P＜0.05).The qRT-PCR results showed that,HO-1 levels in retinal tissues of NC group,DM group,BA group,DAPT group and BA+DAPT group were 1.28±0.32,0.68±0.15,1.03±0.19,0.50±0.13 and 0.73±0.11,respectively;iNOS levels were 0.48±0.08,1.17±0.21,0.89±0.17,1.35±0.15 and 1.10±0.23,respectively,and the differences were statistically significant(F=25.192,35.843,P＜0.05).The Western blot re-sults showed that,compared with NC group,the expressions of Notch1 and Hes-1 in DM group were down-regulated.Compared with DM group,Notch1 and Hes-1 protein expression levels in BA group were up-regulated,while Notch1 and Hes-1 protein ex-pression levels in DAPT group were down-regulated.The expressions of the 2 proteins in BA+DAPT group were lower than those in BA group,and inter-group differences were statistically significant(F=47.626,54.709,P＜0.05).Conclusion It is de-monstrated that BA could reduce blood sugar in diabetic rats,enhance the ability of anti-oxidative stress,improve pathological damage of retina,and thus play a protective role in oxidative damage of ganglion cells,and its mechanism may be related to the activation of Notchl/Hes-1 signal pathway.
NETL
NSTL
万方数据
维普
