Abstract:

[Abstract]  Objective  To investigate the mechanism of the pathogenesis of diabetic nephropathy (DN) bydetecting
the expressions of transforming growth factor (TGF)-β, Smad proteins and α-smooth muscle actin (α-SMA) in kidney biopsyof patients with diabetic nephropathy (DN).   Methods  Twenty-eight patients with DN who underwent renal biopsy were col-lected as DN group. Ten subjects without DN who underwent nephrectomy were taken as control group. The expressions of TGF-β1, TGF-βRⅠ,TGF-βRⅡ,Smad2/3andα-SMA in renal tissues were detected by immunohistochemistry stain.  Results   (1)TGF-β1,TGF-βRⅠ,TGF-βRⅡ,and Smad2/3were expressed in the glomeruli and tubules of both DNgroup and control group, while the expressions of TGF-βand Smad proteins were significantly higher in DN group than those in control group. At the early stage of DN, TGF-βand Smad proteins were significantly expressed even though there was no remarkable lesions observed by light microscopy. There was no correlation between increased expression and the progression of DN. These proteins were not expressed after glomerulusand renal tubule fibrosis. (2) In control group, α-SMA was identified only in the vascular walls, glomerulus and renal tubules, while it was expressed in almost all parts of kidney in DN group.   Conclusion  TGF-βand Smad signals involved in the pathogenesis of DN, which may have similar pathogenesis with immune complex glomerulonephritis

Key words: diabetic nephropathies, transforming growth factor beta, Smad2 protein, Smad3 protein, actins, signal transduction, biopsy, 免疫组织化学