| bjective:To observe the change of TGF-β1/Smads signaling transduction pathway in membranous nephropathy(MN) induced by cationic bovine serum albumin (C-BSA) by surveying the activity of phosphor-smad2/3,which are key cytoplasmic mediators of this signaling.And investigate the effect of TGF-β1/Smads signaling transduction pathway on the expression of PAI-1 and Col IVof MN.To illuminate the regulation and control of TGF-β1/Smads signal transduction pathway in MN. To observe the effect of Sodium ferulate(SF) on TGF-β1/Smads signal transduction pathway of MN, in order to approach the possible therapeutic mechanisms of treating MN with SF. Methods:36 male Spargue-Dawley (SD) rats were randomized into three groups:normal group(A group), model group (B group), SF group(C group),12 for each group. A group, without preimmunizing, non-building model. At the same time of a formal model in B, C groups, the normal saline replaced C-BSA through the vena caudalis injection(2ml/qod), and the same amount of normal saline taked the place of the SF through abdominal cavity injection every day.The remaining two groups were duplicated MN model in rats with the improved Border way. From the first week of formal immune, intraperitoneal injection of SF at a dose of 100 mg·kg-1·day-1. The renal tissue of 6 rats in each group were collected on the 2th and 4th weekends of formal immune. Dynamic detection detect the urine protein in 24 hours and concentration of urine creatinine after fasting. To draw the blood from rats and detected clinical biochemical indicators, to compare respectively the condition of creatinine (Scr), blood urea nitrogen (BUN), creatinine clearance(Ccr) per minute, plasma albumin (Alb), triglyceride (TG) and total holesterol(TC). To take nephridial tissue to judge model’s condition by using light microscope, electron microscope, immunofluorescence technology. And to observe the condition of glomerular basement membrane (GBM) and tubular basement membrane (TBM) in each time spot, the immunohistochemical technique was used dynamically observe the expression of TGF-β1、p-Smad2/3、PAI-1、t-PA、u-PA、ColⅣin each group. We made the correlation analysis of TGF-β1、p-Smad2/3、PAI-1、t-PA、u-PA、ColⅣof glomerular and tubular and renal function, basement membrane thickness, relative content of renal interstitial collagen in each group. Results:(1) kidney morphology:light microscope:renal color, morphology and nephridial tissue pathological lesion were normal, and no IgG fluorescence deposit in A group. In B、C groups, with the experiment proceeding, kidney bulk accreted, color pale, the nephridial tissue pathological lesion gradually aggravate, glomerular capillary wall IgG gradually increased. On 4th weekend kidney enlarged to varying degrees, pale color, glomcrulus intumesced obviously, basement membrane thickening diffusely, parts of capsular space angusty, collagen fibers deposited obviously, interstitium widened even more significantly, fibrosis level heavy. Electron microscopy showed:gradual thickening of GBM and TBM and bulk of electrondense object deposited under glomerular epithelium.Foot process coalesce, the part flatten or vanished. Tubular epithelial cells Swelled. Immunofluorescence showed: glomerular capillary wall and mesangial IgG fluorescence deposited powerful, the intensity between+++ to ++++. The pathological lesion of B group was more heave than the other groups. The pathological lesion of C group was more lighter than B group. Fluorescence intensity had no significant difference in B group and C group(P>0.05). (2) The dynamic condition of TGF-β1、p-Smad2/3、PAI-1、t-PA、u-PA、ColⅣin glomerular and tubular:In A group,TGF-β1、PAI-1、ColⅣexpressed less in glomerular mesangial and cytoplasm of tubular, p-Smad2/3 expressed less in nucleus of glomerular and tubula,t-PA、u-PA express more in nephridial tissue, there was no significant difference in each time spot.With the experiment proceeding, the expression of t-PA、u-PA fall-off,the expression of TGF-β1、p-Smad2/3、PAI-1、ColⅣradually rised in B and C groups, especially for the 4th weekend,the difference were significant(P<0.05).The expression of t-PA、u-PA in B,C groups was less and the expression of TGF-β1、p-Smad2/3、PAI-1、ColⅣwas more than A group,especially for B group; the expression of t-PA,u-PA in C group was more and the expression of TGF-β1、p-Smad2/3、PAI-1、ColⅣwas less than B group,the difference were significant(P<0.05). (3) Change of clinic indexs:the indexs in A group were nomal. The level of Scr, BUN, TG, TC,24h UTP were step up, the level of Ccr, Alb were degraded in B group, especially for Scr, BUN, Alb,24h UTP (P＜0.05). C group compared with B group, the level of Scr, BUN, TG, TC,24h UTP was decreased (P＜0.05), the level of Ccr, Alb was increased (P<0.05), especially for Scr, BUN, Alb on the 4th weekend (P＜0.05). (4) Dependablity of each index on the 4th weekend:In glomerular, TGF-β1 and Ccr, PAI-1 and ColⅣ、thickness of GBM was positive correlation in A group. In B group, TGF-β1 and p-Smad2/3、PAI-1、ColⅣ、GBM thickness were all positive correlation,at the same time, p-Smad2/3 and PAI-1、ColⅣ、thickness of GBM were positive correlation;PAI-1 and ColⅣ、thickness of GBM were all positive correlation; ColⅣand thickness of GBM was positive correlation; In C group,TGF-β1 and p-Smad2/3、Col IV were positive correlation, p-Smad2/3 and PAI-1、ColⅣwere positive correlation, PAI-1 and ColⅣ、thickness of GBM were all positive correlation,ColⅣand thickness of GBM was positive correlation.In Tubular, TGF-β1 and p-Smad2/3、PAI-1、thickness of TBM、relative content of renal interstitial collagen were all positive correlation in B and C groups;p-Smad2/3 and PAI-1、thickness of TBM、 relative content of renal interstitial collagen were positive correlation, at the same time, thickness of TBM and relative content of renal interstitial collagen was positive correlation. Conclusion:(1) TGFβ1/Smads signaling transduction pathway and fibrinolytic system involved in physiologic adjustment of extracellular matrix in normal kidney.(2) In rats renal tissue of MN, TGF-β1can regulate the expression of PAI-1,which promote congestion of extracellular matrix synthesis,and participate in the process of MN. (3)The activation of TGF-β1/Smads signaling transduction pathway increased in rats renal tissue of MN model.TGF-β1/Smads signaling transduction pathway participate in the process of MN which through induced the overbalance of PAI-1/PA.(4)SF played a role in kidney protection through increasing degradation of Col IV which depressing the activation of TGF-β1/Smads signaling transduction pathway, reducing the expression of PAI-1 and increasing generation of PA. |
PDF Full Text Request