The Protective Effect Of N-acetylcysteine On The Podocytes Of Kidney And Mechanisms In STZ-induced Diabetic Rats

Objective:Podocyte that renal capsule visceral epithelial cells, is a unique, highly differentiated cells, as an important components of the glomerular filtration barrier structure, due to its special structure and unique membrane protein molecule determines its the important position in the glomerulus, also determines its its damage plays an important role in the development and progression of diabetic nephropathy. Now research shows that the density and number of podocyte, slit diaphragm and cytoskeleton structure change, intracellular signaling molecules and abnormal activation of signaling pathways is closely related to diabetic nephropathy. To investigate the protective effect of NAC in diabetic rat kidney, this study observing the podocyte symbol protein WT1, key molecules in the slit diaphragm Nephrin, mainly by the podocyte secretion plays an important role of in the development and progression of diabetic nephropathy protein VEGF, and give N-acetylcysteine treatment.Methods:1. Wistar rats as experimental animal to establish diabetes model, randomly divided into normal group, diabetes group and the intervention group, observation time was6weeks and12weeks.2. Collecting blood and urine samples to measure blood urea nitrogen and serum creatinine, urinary protein, renal histopathological changes in rats were observed under light microscope, by immunohistochemical observation nephrin, WT1and VEGF protein expression, by Western blotting method observation the podocyte slit diaphragm molecule nephrin protein expression.3. Application of Image-Pro software Plus6immunohistochemical analysis of average IOD value, application of Image J analysis Western blotting Image with optical density value of the Image. All the data were analyzed by SPSS16.0. Comparisons amongst three or more groups were performed using one-way analysis of variance (ANOVA). Results:1. Successfully established rat model of diabetic nephropathy.2. Diabetic rats showed increased glomerular volume, part of glomerular atrophy, and mesangial matrix proliferation, mesangial area widened significantly, even diffuse mesangial sclerosis, A large number of renal tubular epithelial cell vacuoles degeneration, inflammatory cell infiltration. Compared with DM group, NAC intervention group mesangial cells and extracellular matrix hyperplasia reduce, reduce the infiltration of inflammatory cells.3. The rats renal nephrin expression level was significantly lower in diabetic and intervention group than the same period control group, the difference was statistically significant (P<0.05). Compared with the same period diabetic group, nephrin expression level increased in the intervention group, the difference was statistically significant (P<0.05). Immunohistochemical staining shows that compared with the normal group, diabetes group and intervention group become lighter in color, arrangement also change. Interfered by NAC, brownish yellow substance into color deepened. After giving NAC treatment, brownish yellow substance into coloring deepened.4. Compared with the control group, the diabetic group and intervention group rat kidney WT1immunohistochemical staining was lighter in color, the average IOD value decreased, the difference was statistically significant (P<0.05), treatment with NAC, WT1immunohistochemical staining deepened, the difference was statistically significant.5. Compared with the control group, the expression of VEGF in diabetic group and intervention group was significantly increased in rat kidney, the difference was statistically significant (P<0.05). After immunohistochemical staining, diabetes group and intervention group in the rat kidney VEGF staining obviously increased. Compared with the same period diabetes group, intervention group in the rat kidney VEGF expression level declined, the difference was statistically significant (P<0.05), mmunohistochemical staining color fades.Conelusions:1. Establishment of the rat DN model induced through a tail vein injection of STZ, the reduced levels of nephrin, WT1expression in renal tissue, increased VEGF expression, and correlated with urinary protein excretion.2. NAC therapy could reduce urinary protein excretion, and played a role in renal protection3. Treatment of NAC by up regulating the expression of nephrin, maintain the slit diaphragm integrity, reduce podocyte damage and loss, improvement of vascular permeability, reduce the mesangial matrix and mesangial cell proliferation and played a role in renal protection.