Expression of TGFβ1 in experimental chronic cyclosporine A nephropathy

Objectives To study the effect of transforming growth factor β1 (TGFβ1) on cyclosporine A (CsA) induced tubulointerstitial fibrosis and the effect of blockade of renin angiotensin system on the expression of TGFβ1. Methods The rats were fed on low salt diet for 7 days and then randomly divided into 5 groups: control ( n =7), CsA treated ( n =7), CsA+Verapamil ( n =7), CsA+Enalapril ( n =7) and CsA+Losartan ( n =7). The rats were subected to the subcutaneous injection of CsA (15?mg·kg -1 ·d -1 ) for 4 weeks to develop CsA induced nephropathy model. The expression of TGFβ1 in renal tissue was by using Northern blot method and by immunohistochemical staining method. The expression of biglycan was also detected by using immunohistochemical method. Results The expression of TGFβ1 mRNA and protein in renal tissue was increased in CsA treated rats. The expression of biglycan was also increased in this group. The expression of TGFβ1 and biglycan in rats treated with CsA + Enalapril or with CsA+Losartan was significantly lower than that in the rats treated with CsA only ( P 0.05 ). Conclusions TGFβ1 may be involved in the pathogenesis of renal tubulointerstitial fibrosis induced by CsA. Blockade of renin angiotensin system with Enalapril or Losartan can obviously decrease the expression of TGFβ1 and biglycan to alleviate the progression of chronic CsA nephropathy.