An experimental study of the effect of TGF β_1 on the collagen expression by renal interstitial fibroblasts

Objective To investigate the effect of TGF β 1 on the proliferation, collagen synthesis and collagen mRNA type Ⅰand type Ⅲ expression of renal interstitial fibroblasts in vitro. Methods Fibroblasts were isolated from rat renal medulla. Collagen synthesis and expression of collagen type Ⅰand type Ⅲ mRNA of renal interstitial fibroblasts were investigated by L 3 H proline incorporation and RT PCR, respectively. Results TGF β 1 had a dose dependent stimulating effect on the collagen synthesis of fibroblasts with or without the presence of serum (r= 0 9822, P0 05 and r = 0 9597, P0 05, respectively). TGF β 1 could stimulate the proliferation and collagen synthesis of renal interstitial fibroblasts. By the RT PCR method,TGF β 1 could increase the expression of collagen type Ⅰ and type Ⅲ mRNA of fibroblasts with dose dependent (from 2 to 10 ng/ml) and time dependent effects (from 6 to 48 hours with the concentration of TGF β 1 of 5 ng/ml).Conclusion TGF β 1 at a low concentration may be involved in renal interstitial fibrosis by promoting the collagen synthesis and expression of fibroblasts.