The Effect Of Newer Immunosuppressive On The Expression Of TNF-α And NF-κB In Nephrotoxic Nephritis In Rats

Objective:To investigate the effects of immunosuppressive agents such as Mycohonolate mofetil (MMF),Leflunomide (LEF) and Tarcrolimus therapy on the expression of TNF-αand NF-κB in rats with Nephrotoxic Nephritis.Methods: The first stage: the nephrotoxic serum (NTS) was produced by repeated subcutaneous injection of the renal cortex tissue emulsified in an equal volume of complete Freund's adjuvant (CFA) into four young male New Zealand white rabbits. The second stage: to explore the optimal dosage of NTS in the induction of nephrotoxic serum nephritis (NTN) in rats. The last stage: Total 50 Sprague-Dawley (SD) rats were immunized with a single hypodermic injection of 200μg of rabbit IgG in CFA. 10 rats were randomly drawn from all these rats as the normal group. 5 day later, nephrotoxic nephritis was induced in the other 40 rats by intravenous injection of rabbit anti-rat glomerular basement membrane (GBM) nephrotoxic serum, and these rats were randomly divided into four groups: nephritis group, MMF therapy group, LEF therapy group and tarcrolimus therapy group. Meanwhile, rats in the normal group received saline intravenously. Each of the therapy groups was given intragastric administration once every day. After 2 weeks, serum Total Protein (Tp), Albumin (Alb), Blood Urea Nitrogen (BUN) and Serum creatine (Scr) of every rat were determined and the rats were sacrificed. The pathological features of PAS staining of the kindney were studied. Immunohistochemistry was used to evaluate the change and expression of TNF-αand NF-κB in the tissues of the kidney.Results: A highly active NTS was obtained in two of the four rabbits, determined by indirect immunofluorescence. The optimal dosage of NTS to induce NTN in rats was 4ml/kgBW. Cell number and the crescent formation ratio in the nephritis group were much higher than that in other groups (P<0.01), meanwhile, The LEF therapy group was lower than the tarcrolimus therapy group (P<0.05), and much lower than the MMF therapy group (P<0.01). The crescent formation ratio in the tarcrolimus therapy group was lower than the MMF therapy group (P<0.05). The expression of TNF-αin glumeruli in the nephritis group were much higher than that in the others (P<0.01), The thrapy groups were much higher than that in the normal group (P<0.01), and the LEF therapy group was much lower than the others (P<0.01), meanwhile, the tarcrolimus therapy group was lower than in the MMF therapy group, but there was not significant difference. The expression of TNF-αin renal tubles in the nephritis group were much higher than that in the others (P<0.01), The thrapy groups were much higher than that in the normal group (P<0.01), The difference of the therapy groups was not maked. The expression of NF-ΚB in glumeruli and renal tubles in the nephritis group were much higher than that in the normal group (P<0.01), The thrapy groups were much lower than that in nephritis group (P<0.01), and the LEF therapy group was much lower than the others (P<0.01), meanwhile, the MMF therapy group was higher than that in renal tubles in the tarcrolimus therapy group (P<0.05) and much higher than that in glumeruli in the tarcrolimus therapy group (P<0.01). The thrapy groups had much higher Tp and Alb level and much lower BUN and Scr level than the nephritis group (P<0.01).Conclusion: MMF, LEF and FK506 reduce the expression of NF-κB in the tissues of kidney, with preservation of renal function in experimental crescentic glomerulonephritis, meanwhile, LEF has the best effect in three therapy groups.