Role of transforming growth factor-beta in the growth inhibition of cultured rat mesangial cells in high glucose media.

The present study was designed to test the hypothesis that the inhibitory effect of elevated glucose levels on mesangial cell growth might be mediated by transforming growth factor beta (TGF beta). Increased glucose levels inhibited mesangial cell proliferation in a concentration dependent manner. The addition of a rabbit antipocine TGF beta 1 neutralizing antibody significantly enhanced the cell proliferation in both normal (5.5 mM) and high (50 mM) glucose media (12% and 30% respectively), and almost completely blocked the growth inhibition induced by high glucose media. TGF beta assay demonstrated mesangial cells produced more active than latent TGF beta after growth in high glucose media. We conclude that TGF beta functions as an autocrine cytokine in mesangial cells growth and the production of TGF beta is modulated by high glucose concentration. The growth inhibition induced by high glucose levels may be largely mediated by endogenous TGF beta.