Correlation Between The Expression Of NIK/NF-KB Signaling Molecule And Tubulointerstitial Injury In The Young Rat Of Unilateral Ureteral Obstruction

Objective In order to explore the molecular basis of the progression of tubulointerstitial fibrosis in the rat model of unilateral ureteral obstruction,the expression of four candidate cytokines Nuclear factor-κB inducer kinase,Nuclear transcriptive factor-kappa B,Nuclear factor-κB inhibitor proteins and monocyte chemoattractant protein-1 are investigated in the present study.The other objective is to probe into the interfering effects of angiotensin converting enzyme inhibitor(ACEI)-benazepril and combined with angiotensinⅡtypeⅠreceptor angonist(ARB)-Losartan on the four cytokines mentioned above in the process of tubulointerstitial fibrosis lesion in rats with unilateral ureteral obstruction.Methods 80 Young male Wistar rats at the age of 2-3 weeks weighing 80g～100g were randomly divided into 3 groups:control group(sham operated group,n=24),UUO untreated group(n=28),UUO with ACEI and ARB treated group,(n=28).Each group was also randomly divided intofore groups in term of 3d,7d,14d,28d after surgery(n=6～7).Under pentobarbitale sodium anesthesia,the rat's left ureter was ligated at two points and cut between the ligatures.Then the unilateral ureteral obstructive rat model was established.Sham-operated rats had their ureters manipulated but not ligated.ACEI and ARB began to administed the day after surgery,untreated and control rats were received equal 0.9%NaCLby daily gastric gavage.Rats were killed after 3,7,14,28 days.Use HE stain to examine the area of pathological changes.The changes of expression of NIK,NF-κB(P65/Rel-A),IκB and MCP-1 proteins were analyzed by routin immunohistochemica method,then analyze the mean density with the Imagepro-plus analysis system.The experimental data was demonstrated in mean±standard erroe(deviation).The analysis of variance test and the relation about datas were used by SPSS11.5,a statistic software.Results①Nephridial tissue's construction showed normal in control group in HE stain.In untreated group,there was different degree of interstitial fibrosis,interstitial leukocyte infiltration,tubular dilation,necrosis,basal membrane breakage and the relative area of renal tubulointerstitium expansion in the obstructed kidneys of 3,7,14,28 days after UUO.The relative area of renal tubulointerstitium was significantly increased in the obstructed kidneys compared with that of control group and treated group(P＜0.05).However,the relative area of renal tubulointerstitium of treated group significantly decreased compared with that of untreated group(P＜0.05).②By routine immunohistochemical method,the protein level of NF-κB(P65/Rel-A),NIK and MCP-1 in tubule epithelial cellular in untreated group 3,7,14,28days was various and significantly higher than that in treated and control group, (P＜0.05)and P65/Rel-A translocation from plasm to nuclear increased markedly simultaneously. The positive signal of hybridization in cytoplasm converted into nuclear gradually.In untreated groups,the protein level of IκB was significantly lower than that in control group and treated group in 3d,7d,14d,28d.③Statistics results has shown a positive correlation between NF-κB (P65/Rel-A),NIK and MCP-1 expression on localization and time phase(r=0.818,0.675,0.791, P＜0.05).However,the tendency of those factor's expression were all decreased in each treated groups.The correlation between NF-κB(P65/Rel-A),NIK and MCP-1 and IκB expression on localization and time phase are negative(r=-0.857,-0.758,-0.690,P＜0.05).Our results have suggested that the ACEI and ARB could inhibited the upregulation of NF-κB(P65/Rel-A) expression and its nuclear translocation from cytoplasm.The significant difference were observed between all groups in different time points(P＜0.05).Conclusion Our results have shown NIK/NF-κB signal pathway may play an important role on renal tubulointerstitial fibrosis during chronic renal disease in UUO young rats.The interfering treatment with ACEI and ARB could ameliorate tubulointerstitial fibrosis in remnant renal tissues,and there may have a AngⅡ—NIK—NF-κB--MCP-1 signal pathway on renal tubulointerstitial fibrosis advancing.