ARAP1/AT1R Signaling Pathway In Diabetic Nephropathy The Role Of Pathogenesis And Intervention Research

Objective: To investigate whether ARAP1 expression and the regulation of AT1 R in type 2 diabetic db / db mice and glomerular mesangial cells cultured in vitro are related to the proliferation of mesangial cells,extracellular matrix accumulation and oxidation Kang hyperthyroidism,leading to diabetic nephropathy.And to observe the protective effect of ursolic acid on type 2 diabetic db / db mice and its effect on ARAP1 and AT1 R expression.Methods: 9-week-old db / db mice(BKS.Cg-leprdb / leprdb)were randomly divided into diabetic nephropathy group(db / db group,n = 10)and ursolic acid treatment group,N = 10).The same age db / m mice(BKS.Cg-leprdb / +,n = 10)as a control group.The body weight of mice in each group was measured weekly;blood glucose was measured regularly;urinary albumin / creatinine ratio was measured at 20 weeks of age by urine.The pathological changes of renal tissues were observed with light microscope.The expressions of angiotensin II receptor type 1 receptor(ARAP1),angiotensin II type 1 receptor(AT1R)and extracellular matrix fibronectin(FN)Variety.The expression of angiotensin II receptor type 1 receptor(ARAP1),angiotensin II type 1 receptor(AT1R),NADPH oxidase 4(NOX4),NADPH oxidase 2(NOX2),FN and collagen IV Collagen IV)m RNA expression changes.Western blotting was used to detect the expression of ARAP1,AT1 R,NOX4,NOX2 and TGF-?1(TGF-?1),FN,collagen IV(Collagen IV)protein expression changes.The rat glomerular mesangial cells cultured in vitro were divided into normal glucose group(NG),normal glucose negative control group(HG),high glucose negative control group,normal glucose + ARAP1 si RNA and high glucose + ARAP1 si RNA group-blot was used to detect the expression of ARAP1,AT1 R and FN in each group.Results :The body weight of db / db mice at each week of age was significantly higher than that of db / m group(p <0.01),The body weight of db / db mice decreased most significantly after 8 weeks of treatment(p <0.01).Compared with db / m mice,the blood glucose level of db / db mice increased significantly at each week of age(p <0.01),UA intervention for 6 weeks reduced the blood glucose of db / db mice(p<0.05),and the hypoglycemic effect became more obvious after 10 weeks(p <0.01).Compared with the db / db mice The urinary albumin / creatinine ratio was significantly increased in mice(p <0.01).Ursolic acid administration reduced urinary albumin / creatinine ratio(p <0.05).Compared with db / m mice,db / db mice showed obvious glomerular basement membrane thickening and mesangial matrix accumulation,glomerular sclerosis index increased significantly(p <0.01),ursolic acid The treatment group db / db mice kidney tissue lesions significantly improved(p <0.05),glomerular sclerosis index was significantly reduced(p <0.05).Compared with the db / m group,the expression of ARAP1,AT1 R and FN in the db / db group was significantly increased(p <0.01),while the ursolic acid treatment inhibited the expression of ARAP1(p <0.05),AT1R(p <0.05),FN(p <0.05)expression.The results of real-time quantitative PCR showed that the expression of ARAP1,AT1,NOX4,2,FN and Collagen IV m RNA in db / db mice increased significantly(p <0.01)Acid therapy significantly reduced the above abnormalities.Western blot results showed that the expression of ARAP1,AT1,NOX4,2,TGF-?1,FN and Collagen IV in db / db mice increased significantly compared with db / m mice(p <0.01).Ursolic acid treatment can significantly reduce the abnormal expression of these indicators in renal tissue.The expression of ARAP1,AT1 R and FN in glomerular mesangial cells cultured in high glucose environment in vitro was significantly higher(p <0.01)than that in normal glucose group.ARAP1 si RNA was transfected into normal and hyperglycemic groups,respectively.Compared with high glucose group,ARAP1 si RNA inhibited ARAP1 expression and decreased AT1 R expression.Conclusion: Increased ARAP1 expression in the renal cortex of db / db mice with type 2 diabetes mellitus promotes the expression of AT1 R,enhances its sensitivity and further promotes the expression of NOX4?2,resulting in the enhancement of oxidative stress and promotion of the expression of TGF-?1,FN and COIIV Expression,resulting in renal fibrosis.Ursolic acid may reduce renal damage in type 2 diabetic db / db mice by down-regulating ARAP1 / AT1 R signaling pathway and inhibiting extracellular matrix,renal fibrosis and oxidative stress.The expression of ARAP1,AT1 R and FN in glomerular mesangial cells cultured in vitro was significantly increased.Targeting inhibition of ARAP1 expression in mesangial cells reduces the expression of AT1 R and attenuates extracellular matrix secretion.