Protective Effects And Mechanisms Of Nrf2/ARE Signaling Pathway For Hyperuricemia Promoting Chronic Kidney Disease

Objective:In this study,we built high uric acid cell model,through the Nrf2 inducers SFN intervene to observe activation of Nrf2/HO-1 signaling pathway of renal tubular epithelial cells indicators related to oxidative stress,and to investigate the protective effect and mechanism of Nrf2/HO-1 signaling pathway in hyperuricemia-promoting chronic kidney disease.Methods:We divided renal tubular epithelial cells into 8 groups:Goup A,normal tubular epithelial cells cultured with 1640 medium for 48 hours without uric acid and SFN;Goup B,SFN was added to 1640 medium to reach a SFN concentration of 5 ?mol/L and then the cells cultured for 48 hours;Goup C,uric acid was added to 1640 medium to reach a uric acid concentration of 300 ?mol/L and chen the cells cultured for 48 hours;Goup D,uric acid was added to 1640 medium to reach a uric acid concentration of 300 ?mol/L,simultaneously SFN was added to make a SFN concentration of 5 ?mol/L,and then the cells cultured for 48 hours;Goup E,uric acid was added to 1640 medium to make a uric acid concentration of 500 ?mol/L and then the cells cultured for 48 hours;Goup F,uric acid was added to 1640 medium to make a uric acid concentration of 500 ?mmol/L,simultaneously SFN was added to make a SFN concentration of 5 ?mol/L,which was followed by cell culture for 48 hours;Goup G,uric acid was added to 1640 medium to reach a uric acid concentration of 700 ?mol/L and then the cells cultured for 48 hours;Goup H,uric acid was added to 1640 medium to make uric acid concentration reached 700?mol/L,and SFN was simultaneously added to make a SFN concentration of 5?mol/L,which was followed by cell culture for 48 hours.The cell viability,MDA,ROS and SOD were detected.The expression and distribution of Nrf2 in the cells were observed by immunofluorescence.The expression of Nrf2 and HO-1 in the cells were detected by Western blot.Statistical analysis was performed with above data and p<0.05 was considered as statistically significant.Result:1.SFN can reduce the high concentration of uric acid on renal tubular epithelial damage:With the increase of uric acid concentration,the cell viability and the content of SOD in group E and group G decreased gradually and the level of MDA and ROS increased continuously(all p<0.05).While cell viability and SOD content increased significantly,and MDA and ROS levels decreased significantly(p<0.05),after adding SFN F group and H group,.2.SFN treatment increased the nuclear transcription of Nrf2 protein,and also up-regulated HO-1 protein expression:The results of immunofluorescence showed that Nrf2 was distributed in the cytoplasm without SFN,and there was a small amount of Nrf2 in the nucleus.When the cells were stimulated with high concentration of uric acid,the content of Nrf2 in the cytoplasm was decreased compared with the control group.When SFN was added,Nrf2 was greatly transferred to the nucleus in both control and experimental groups,and the content of Nrf2 in cytoplasm was greatly reduced(p<0.05).Western blot results showed that when the cells were stimulated with high concentration of uric acid,the expression of Nrf2 in the cytoplasm and nucleus decreased,and the difference between group E and group G was statistically significant(p<0.05).While after adding SFN,Nrf2 can not only promote the transfer of Nrf2 into the nucleus,but also induce the cells to produce more Nrf2 to exert anti-oxidant effect.Therefore,the expression of Nrf2 in the cytoplasm and nucleus of group F and group H is higher than that of group E and Group G had statistical difference(p<0.05).The content of HO-1 in group C was higher than that in group A,but the expression of HO-1 was gradually decreased when the uric acid concentration was increased(p<0.05).The expression of HO-1 was significantly increased after adding SFN(P<0.05).Conclusions:1.Hyperuricemia can damage renal tubular epithelial cells,and accelerate the progress of chronic kidney disease.2.Nrf2/HO-1 signaling pathway is involved in the progression of chronic kidney disease promoted by hyperuricemia.3.SFN can protect hyperuricemia-induced epithelial cell damage by activating Nrf2/HO-1 signaling pathway.