Based On The Klotho/TGF-?1/Smad2 Signaling Pathway, The Effect Of Liuwei Dihuang Decoction On The Anti-fibrosis Of The 5/6 Nephrectomy Rat Model Was Studied

Objective:previous basic studies have confirmed that Liuwei Dihu-ang decoction can improve fibrosis by inhibiting TGF-?/Smad2 signal pathway,but the upstream regulation mechanism is not fully understood.Studies have shown that Klotho is involved in the regu-lation of TGF-?/Smad2 signal pathway.This study intends to explore the specific mechanism of Liuwei Dihuang decoction in improving renal fibrosis from the perspective of Klotho,so as to provide new ideas and reliable experimental basis for its clinical treatment of CKDMethods:60 SPF SD rats were randomly divided into four groups blank group,sham operation group,model group,Liuwei Dihuang decoction group and enalapril group.The course of treatment of the five groups was 8 weeks.Blood,urine and kidney samples were taken after 8 weeks.Biochemical method was used to evaluate the changes of renal function,HE staining was used to evaluate the tubulointerst-itial injury index,Masson staining was used to evaluate the percenta-ge of tubulointerstitial collagen area,and immunohistochemical met-hod was used to detect the protein expression of Klotho,TGF-?1 and p-Smad2.To explore the hypothesis that Liuwei Dihuang decoction alleviates renal fibrosis by regulating Klotho/TGF-?1/Smad2 signal pathway.Results:1.After modeling,compared with the blank group and sham operation group,the weight gain of rats in the other groups was relatively small;compared with the model group,the body weight of rats in the drug treatment group increased significantly,and the difference between the two groups was statistically significant(P<0.05).There was no significant difference in body weight between Liuwei Dihuang pill group and enalapril group(P>0.05)2.Compared with the sham operation group,the levels of 24hUAlb,Scr and BUN in each model group were significantly increased,and the renal function was worse than that in the sham operation group Compared with the model group,the 24hUAlb,Scr and BUN in the drug intervention group were significantly decreased,and the renal function was recovered,and there were significant differences among the three groups(P<0.05).Compared with enalapril group,there was no significant difference in the levels of 24hUAlb,SCr and BUN in Liuwei Dihuang decoction group3.Staining showed that the morphology and structure of kidney in the blank group and sham operation group was normal,and the renal pathological changes in the model group were more severe,especially in the renal interstitium.The glomerular and tubulointerstitial lesions in the Liuwei Dihuang decoction group and enalapril group were significantly less than those in the model group.The renal tubulointerstitial injury index in the model group was significantly higher than that in the sham operation group and the drug treatment group(P<0.01).The renal tubulointerstitial injury index in the Liuwei Dihuang decoction group was higher than that in the sham operation group,but significantly lower than that in the model group(P<0.01).4.Masson staining showed that trace or small amount of blue collagen deposition could be seen in blank group,sham operation group and drug treatment group.There was a large amount of blue collagen deposition in the model group.Quantitative analysis of tubulointerstitial collagen area showed that the tubulointerstitial collagen area percentage in model group was significantly higher than that in sham operation group and drug treatment group(P<0.01),and the degree of renal interstitial injury in Liuwei Dihuang decoction group was more significant than that in enalapril group(P<0.01).5.Immunohistochemistry showed that the expression of Klotho protein in the model group was significantly lower than that in the sham operation group(P<0.01),and the expression of TGF-?1 and p-Smad2 in the model group was significantly higher than that in the sham operation group and each drug group(P<0.01).The expression of Klotho protein in the Liuwei Dihuang decoction group was higher than that in the model group(P<0.01),and the expression of TGF-?1 and p-Smad2 in the model group was lower than that in the model group(P<0.01).6.There was a significant negative correlation between Klotho and TGF-?1,Klotho and p-Smad2 protein expression(p<0.0001),and a significant positive correlation between TGF-?1 and p-Smad2 protein expression(p<0.0001)Conclusion:(1)Liuwei Dihuang decoction can reduce the renal function and renal pathological damage in rats with 5-stroke and 6-nephrectomy,and has the effect of protecting and repairing renal tissue.(2)Liuwei Dihuang decoction suppressed the expression of TGF-?1/Smad2 signal pathway in the process of promoting fibrosis in 5×6 nephrectomized rats,and could improve the accumulation of extracellular matrix.(3)the mechanism of Liuwei Dihuang decoction in delaying renal interstitial fibrosis may be related to the up-regula-tion of Klotho protein level,thus inhibiting the expression of TGF-?1 protein and reducing the phosphorylation of Smad2,that is,Liuwei Dihuang decoction can inhibit Klotho/TGF-?1/Smad2 signal pathw-ay in 5-stroke-6 nephrectomized rats,thus protecting the kidney.