| ObjectiveTo observe the effect of human umbilical cord mesenchymal stem cells(hUCMSCs)on diabetic rats model of early retinopathy,and to investigate the mechanism of hUCMSCs in treating diabetic retinopathy(DR)by regulating Nrf2/HO-1 pathway modulated by tert-butylhydroquinone(tBHQ).MethodsThe diabetic rat model was induced by intraperitoneal injection of streptozotocin(STZ).The experimental animals were divided into 6 groups:normal control group(group C),diabetic control group(group D),hUCMSCs injection group(group M),tBHQ treatment group(group T),tBHQ+h UCMSCs combined treatment group(group MT),ATRA+hUCMSCs combined treatment group(group MA).The changes of general growth status,weight and glucose of rats in each group were observed regularly.After 18 weeks of modeling,HE of retinopathy was detected,and the expression of IL-6,IL-10,TNF-α,iNOS and IFN-γ in serum was detected by ELISA method.At the same time,the levels of serum SOD,MDA and GSH-Px were detected to determine the level of oxidative stress in rats.Western Blot(WB)method detected the expression of COX-2,VEGF,Nrf2,HO-1,NF-kappa B in retina.Real-time quantitative PCR was used to detect the expression of IL-1 β,TNF-α,Nrf2 and HO-1 mRNA in retina.Results1.The weight of normal rats increased gradually,but the weight of diabetic model rats was lower than that of normal rats.after 6 weeks,there was a difference in weight between the group treated with tBHQ and the group without tBHQ(P < 0.05).After modeling,the glucose of other groups was significantly higher than that of group C;after 10 weeks of modeling,the glucose of group C was normal.The glucose of groups D,M and MA remained high,while the glucose of groups T and MT treated with tBHQ was lower than them.2.In group C,the retinal internal limiting membrane was smooth and intact,the ganglion cells were neat and regular.In group D,HE showed that the retinal ganglion cell layer showed obvious vacuolation,the inner and outer nuclear layers were disordered,and the boundary between each layer was blurred.The structure of retina in group M and T was significantly improved.Compared with group M and T,the vacuolization of ganglion cell layer in MT group was significantly improved.In group MA,the structure of retina became thinner and the vacuolation of ganglion cell layer was obvious.3.ELISA showed that the levels of IL-6,IL-10,TNF-α,iNOS and IFN-γ in serum in group D were significantly higher than those in group C(P <0 05).The levels of IL-6,IL-10,TNF-α,iNOS and IFN-γ in group T were significantly lower than those in group D(P < 0 05).The levels of IL-6,TNF-α and IFN-γ in MA group were significantly higher than those in group M(P < 0 05).4.In the comparison of SOD and GSH-Px among the each groups,the level SOD and GSH-Px in group D was significantly lower than that in group C(P <0.05).The level of MDA in group T was significantly higher than that in group D.Compared with M group,there were significant differences in MT and MA groups,among which,MT group increased and MA group decreased.The trend of MDA in each group was opposite to that of SOD and GSH-Px.5.The results of WB and PCR showed that the m RNA and protein expression levels of inflammatory cytokines,Nrf2 and HO-1 in group D were higher than those in group C.The expression of inflammatory cytokines in group M and T were lower than those in group D(P < 0.05).The expression of Nrf2 and HO-1in T group were higher than those in group D(P < 0.05).The levels of inflammatory cytokines such as COX-2 and VEGF in MT group were lower than those in both group M or T,respectively.The expression levels of Nrf2 and HO-1in group MA were higher than those in M group,while the expression of Nrf2 and HO-1 in group MA were lower than those in M group.Conclusion1.The modle of diabetic ratsby intraperitoneal injection of STZ had a low mortality.HE showed that the structure of each layer of the retina was disordered,which conformed to the histological characteristics of diabetic retinopathy.2.Intravitreal injection of h UCMSCs can improve the structure of damaged retina,inhibit the expression of inflammatory factors COX-2,NF-κ B,IL-1β and TNF-α,reduce the level of VEGF and reduce neovascularization.3.t BHQ can significantly enhance the level of antioxidation,inhibit the level of oxidative stress and reduce the levels of inflammatory factors such as IL-6,IL-10,TNF-α,iNOS and IFN-γ in the whole body.At the same time,it can inhibit inflammatory factors such as IL-1 β,TNF-α and NF-κ B in the retina,and enhance the antioxidant capacity of the retina.4.t BHQ combined with hUCMSCs therapy,compared with simple tBHQ therapy,can not enhance the level of systemic antioxidant stress,but can significantly inhibit the level of oxidative stress and inflammation of the retina.Therefore,t BHQ can enhance the level of antioxidation in diabetic rats through Nrf2/HO-1pathway,promote hUCMSCs to play a therapeutic role in the retina,and reduce retinal injury. |
PDF Full Text Request