The Effect And Mechanism Of Hyperuricemia On Diabetic Nephropathy

Objective: By collecting clinical data,the correlation between hyperuricemia and diabetic nephropathy was analyzed.Taking the inflammatory response of Human renal tubular epithelial cells(HKC)as the entry point,to investigate the effect of GLUT9-mediated inflammatory response on the transdifferentiation of HKC cells treated with high glucose and high uric acid,so as to provide a theoretical basis for the diagnosis and treatment of diabetic nephropathy.Methods: 1.A total of 552 patients with type 2 diabetes were collected from the Department of Endocrinology of Gansu Provincial People’s Hospital.General data and biochemical indexes of the patients were collected.The urinary albumin excretion rate was divided into non-DN group((UAER)<20ug/min).Early DN group((UAER)20-200ug/min);Clinical DN group(UAER)>200ug/min.spearman correlation analysis and multiple Logistic regression were used to analyze the risk factors of clinical diabetic nephropathy.The predictive value of UA was evaluated by ROC curve.2.CCK8 method was used to detect the effect of different concentrations of anhydrous glucose and uric acid on the relative viability of HKC cells,and to screen and determine the concentration of high glucose/high uric acid cell model.Under the condition of high glucose/high uric acid,GLUT9 protein expression was detected by immunofluorescence method,mRNA expression of GLUT-9,TLR4,NF-κB,α-SMA and E-cadherin gene was detected by QRT-PCR,and TNF-α and IL-6 levels were detected by ELISA.3.After siRNA interfered with GLUT9 mRNA expression in HKC cells under high glucose/high uric acid conditions,the mRNA expression of TLR4,NF-κB,α-SMA and E-cadherin were detected by QRT-PCR,and the contents of TNF-α and IL-6 were detected by ELISA.Resμlts:1.The indexes of diabetes course,BMI,SBP,fasting insulin,UAand ALT in clinical DN group were significantly higher than those in non-DN group and early DN group(P<0.05);Renal function indexes scr,UAER,UACR and 24 h urinary protein were significantly higher than those in non-DN and early DN groups(P<0.05);spearman correlation analysis showed that the correlation index r between SUAlevel and scr,UAER,UACR and 24 h urinary protein index were 0.280,0.705,0.330 and 0.365,respectively;Logstic regression analysis showed that UAand diabetes course were risk factors for clinical DN;The area under ROC curve(AUC)calculation shows: In addition,the optimal cut-off point of ROC curve for predicting clinical diabetic nephropathy was 438.5 umol/L,and the optimal cut-off point of ROC curve for predicting clinical diabetic nephropathy was 16.5,as determined by the maximum approximate landing index.2.After cultured with 17 mmo L/L anhydrous glucose,the proliferative activity of cells increased.When the glucose concentration increased from 25 mmo L/L to 45 mmo L/L,cell proliferation activity decreased with the increase of glucose concentration,and 25 mmo L/L glucose had the lowest inhibitory effect on cell proliferation.3.HKC cells were treated with uric acid in a concentration-dependent way(P<0.05),and the cell inhibition rate was close to the half-inhibition rate when the concentration of uric acid was0.4μmo L/L.4.GLUT9 red fluorescence was enhanced in H-Glu,HUAand HUA+H-Glu groups compared with Control group.The relative expression level of GLUT9,TLR4,NF-κB and α-SMA mRNA was significantly increased(P<0.05),while the relative expression level of E-cadherin mRNA was significantly decreased(P<0.05).GLUT9 red fluorescence was enhanced in HUA+H-Glu group compared with H-Glu group and HUA group.GLUT9,TLR4,NF-κB,α-SMA mRNA relative expression levels were significantly increased(P<0.05),while E-cadherin mRNArelative expression levels were significantly decreased(P<0.05).5.Compared with siRNA-NC group,the relative expression of mRNA of GLUT9 gene in GLUT9-siRNA1 group was significantly decreased(P<0.05).The relative expression of GLUT9 mRNAin GLUT9-Si RNA2 group and GLUT9-Si RNA3 group was significantly decreased(P<0.05),and the GLUT9 expression in GLUT9-Si RNA2 group was the lowest.6.In high-sugar and high-uric acid environments,siRNAsilenced the GLUT9 gene.Compared with Control group,mRNA expression levels of TLR4,NF-κB and α-SMA genes in Model group were significantly increased(P<0.01),while the relative expression level of E-cadherin gene mRNAwas significantly decreased(P<0.01).Compared with Model group,mRNAexpression levels of TLR4,NF-κB and α-SMA genes in siRNA-GLUT9 group were significantly decreased(P<0.01),and relative mRNAexpression levels of E-cadherin gene were significantly decreased(P<0.01).Conclusion:HUA is a risk factor for diabetic nephropathy and an important indicator for predicting the occurrence and development of hyperuricemia and diabetic nephropathy.After stimulation of renal tubule epithelial cells by high glucose and high uric acid,TLR4/NF-κB signaling pathway is activated to promote the release of pro-inflammatory factors.In addition,GLUT9 expression is promoted,uric acid absorption is increased,and inflammatory response of renal tubule epithelial cells is further up-regulated,eventually leading to fibrosis of renal tubule epithelial cells.However,in high glucose and high uric acid environment,GLUT9 gene expression silenceddown-regulated inflammatory level and reduced uric acid reabsorption by inhibiting TLR4/NF-κB signaling pathway,Thus effectively prevent renal tubular epithelial cell transdifferentiation and fibrosis.