Therapeutic Effects Of Nintedanib On Kidney Fibrosis In Db/db Mice With Diabetic Nephropathy

Background:Diabetic nephropathy(DN),as a common cause of end-stage renal disease(ESRD)in most parts of the world,includes areas with limited resources for renal replacement therapy.The morbidity of diabetes is increasing rapidly worldwide,result in the remarkable elevate in the incidence of DN and ESRD.Once DN deteriorated to ESRD,the therapy would be very difficult.The high cost of treatment,unsatisfied efficacy and poor prognosis has bothered scholars in diabetes and renal disease for a long time.Traditionally,DN was thought to be induced by the interactions of hemodynamic factors and metabolic factors.However,current studies show that inflammatory mediators play an important role in the early development of DN.Recent studies indicate that the activation of tyrosine kinase receptor(TRP)could induce the generation of variable message factors involved in the development of interstitial fibrosis,which plays dominant role in the process of renal fibrosis.Nintedanib(BIBF1120)is a triple kinase inhibitor of PDRFG,FGFR,VEGFR and SRC family kinase,approved by FDA in the treatment of IPF.However,report about the pharmacological effects of BIBF1120 in the treatment of renal fibrosis is absence.Considering the role of RTK in the process of renal fibrosis,low selective RTK receptor inhibitor BIBF1120 has the potential to effectively to deduce the fibrosis degree of DN.ObjectiveThis study is designed to explore that weather BIBF1120 could effectively deduce the fibrosis degree of DN and retard DN progress in the model of db/db DN mouse,which could work as experimental basis of the further research and development of new anti-fibrosis drugs.MethodsEstablish db/db DN mouse model and set up BIBF1120 intervention group.The mouse are divided in three different groups:db/m group,db/db+DMSO group and db/db+BIBF1120 group.All the mouse are 8 weeks old,killed after two weeks intervention at 10 weeks old.Reserve the serum,urine and kidney samples,and measure the weight of kidney.Then determine the fasting blood sugar,insulin,Scr,T-CHO,TG and UACR,observe histological appearance of mouse kidney under high magnification microscope.Compare the amount of extracellular matrix(ECM)protein I and CD68 of kidney tissue by immunohistochemical methods and do semi-quantitative analysis.Results1.kidney function and kidney coefficient analysis:degree of Scr,UACR and kidney coefficient in db/db group is higher than db/m(p<0.05),and application of BIBF1120 could improve this trend.degree of Scr and UACR in db/db+BIBF1120 group is lower than db/db+DMSO group(p<0.05).2.pathological appearance:db/db group showed obviously morphological lesion,character in tubular expansion,epithelial atrophy and interstitial expansion company with collagen accumulation.On the contrast,the degree of fibrosis in db/db+BIBF1120 group is moderate.Optical density analysis by Masson and PAS staining showed BIBF 1120 could remarkably decrease the size of fibrosis region and GMI(p<0.05).3.level of renal tubules EMT:the level of ECM collagen I in db/db group is significantly higher than db/m group(p<0.05).And collagen I in db/db+BIBF1120 group is significantly lower than db/db+DMSO group(p<0.05).4.detection of macrophages infiltration:the amount of CD68 positive macrophages in db/db group is much more than db/m group(p<0.05).Application of BIBF 1120 result in the significant decrease of macrophages infiltration(p<0.05).Conclusion:BIBF 1120 could protect renal function in DN patients,decrease the fibrosis degree of kidney.