Based On TGF-β1/Smads Signaling Pathway Researching The Effect And Mechanism Of Shenxiankang On Inhibiting Renal Interstitial Fibrosis

Objective: The animal model of renal interstitial fibrosis was produced by unilateral ureteral obstruction(UUO)method,we conduct an experiment to observe the effects of Shenxiankang on the rats in each group of general situation,kidney functions,Renal pathological changes,and expression of TGF-β1、Smad2、Smad3、Smad7.Investigating the positive effects and its possible mechanism of shenxiankang on inhibiting renal interstitial fibrosis.Methods: The Sixty male SD rats were randomly divided into sham operated group(SOR group),UUO model group,UUO model treated with shenxiankang high dose group,UUO model treated with shenxiankang middle dose group,UUO model treated with shenxiankang low dose group,UUO model treated with benazepril group.Every group has ten rats.Among them,the SOR group only cut abdominal cavity and separate the left ureter,the other groups on the basis of the above steps,left ureter was be ligatured and cutted.From the first day after operation,Shenxiankang low dose group fed with Shenxiankang decoction(0.7ml/100g·d),shenxiankang middle dose group fed with Shenxiankang decoction(1.3ml/100 g ·d),shenxiankang high dose group fed with Shenxiankangdecoction(2.0ml/100 g · d),and benazepril group fed with benazepril(10mg/kg·d).Both SOR group and UUO group were received equal Saline through intragastric administration.At the two time points(7d/14d),weighing all rat’s body weight before Five rats in each guoup were randomly selected and killed respectively,then Removed the left kidney.Recorded the body weight and kidney weight,and calculated the ratio of kidney weight to body weight(KW/BW).through the Abdominal aorta collected blood samples,to Measured the serum creatinine(Scr)and blood urea nitrogen(BUN).Observed the pathological changes in kidney by Masson and HE staining,the expression of α-SMA andTGFβ1、Smad2、Smad3、Smad7protein detected by immunohistochemistry and western blot.Results: 1.Body weight 、KW/BW and renal function: Compared with the SOR group,The Body weight of the other groups,which had been received the operation of UUO,was significantly decreased at different time points(P<0.05).Compared with the UUO model group,the body weight of Shenxiankang middle dose group、Shenxiankang high dose group were significantly increased at day14(P<0.05),shenxiankang all dose groups have no obvious change in KW/BW,but entered in a downtrend(P>0.05)at different time points;The level of both Scr and BUN on Shenxiankang all dose group were decreased at various time points(P<0.05).middle and high dose group the effect is more obvious(P<0.05).2.Kidney tissue morphology and renal pathologic change: SOR group’s kidney size are normal,appearance of kidney is dark red,surface feels smooth and elastic,renal capsule not easy to bepeeled,cortex and medulla have clear boundary.There is a visible view that swelling kidney,owe smooth surface,renal capsular easy to be peeled,hydronephrosis,cortical atrophy thinning of UUO model group at day 7.More serious kidney seeper,more obvious ortical atrophy thinning at day 14.Shenxiankang all dose group and benazepril group were similar to UUO model group,but the degree of Kidney swelling,and cortical thinning lighter than model group.HE and Masson staining showed that both glomerular and tubular morphology were normal at each time point and there was no pathological changes in SOR group.There is no renal tubule expansion or atrophy,and inflammatory cell infiltration,renal interstitial rarely contain aizen collagen fiber structure.In the other groups,renal cortical became thin,and showed varying degrees of renal tubule expansion or atrophy,epithelial cell degeneration,renal interstitial edema and inflammatory cells infiltration,etc.Compared with the SOR group,the tubulointerstitial damage index and collagen staining scores in the other groups significantly increased(P<0.05)at each time point.Compared with the UUO group,The tubulointerstitial damage index and collagen staining scores in both Shenxiankang medium/high dose group and benazepril group were significantly decreased(P<0.05)at each time point.There was no significant differences between the Shenxiankang middle/high dose group and benazepril group on this item(P>0.05).Shenxiankang low dose group can improve the pathological damage,but the effects not as good as Shenxiankang medium/high dose group and benazepril group(P<0.05).Therewas no statistically significant difference between medium and high dose group(P>0.05).3.α-SMA、TGF-β1、Smad2/3、Smad7: According to the results of Immunohistochemical staining and Western blot,Compared with the SOR group,the expression of α-SMA 、 TGF-β 1 、 Smad2/3significantly increased(P<0.05),the expression of Smad7 significantly decreased(P<0.05).Compared with UUO group,except the shenxiankang low dose group,the expression ofα-SMA 、TGF-β1、Smad2/3 significantly decreased(P<0.05),the expression of Smad7 significantly increased(P<0.05)on the other treatment groups.There was no significant differences between the Shenxiankang middle/high group and benazepril group(P>0.05).Shenxiankang low dose group showed the trendency of inhibiting the expression of α-SMA 、TGF-β1、Smad2/3,promoting the expression of Smad7,but there was no statistical significance.but the effects not as good as Shenxiankang medium/high dose group and benazepril group.Conclusion:1.Shenxiankang increasing the UUO rat’s body weight,reducing the kidney weight/body weight ratio,improving renal function;reducing renal tubular interstitial damage index and collagen staining scores,has certain protective effect.2.Shenxiankang decoction can inhibit the expression of TGF-β 1,Smad2 and Smad3,promoting the expression of Smad7,thus affecting the TGF-β1 / Smads signal pathway,reducing the expression of α-SMA and collagen fibers,this may be one of the mechanism that shenxiankang inhibiting renal interstitial fibrosis.3.Shenxiankang has certain positive effect on inhibiting renalinterstitial fibrosis,in which shenxiankang middle/high dose group has obvious effects,that similar to benazepril group,remind a positive correlation between the dosage of shenxiankang and effect of treatment.