ROLE OF TRANSFORMING GROWTH-FACTOR-BETA IN THE GROWTH-INHIBITION OF CULTURED RAT MESANGIAL CELLS IN HIGH GLUCOSE MEDIA

The prenent study was designed to test the hypothesis that the inhibit ory effect of elevated glucose levels on mesangial cell growth might b e mediated by transforming growth factor beta (TGF beta). Increased gl ucose levels inhibited mesangial cell proliferation in a concentration dependent manner. The addition of a rabbit antipocine TGF beta1 neutr alizing antibody significantly enchanced the cell proliferation in bot h normal (5.5mM) and high (50mM) glucose media (12% and 30% respective ly), and almost completely blocked the growth inhibition induced by hi gh 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 mesang ial cells growth and the production of TGF beta is modulated by high g lucose concentration. The growth inhibition induced by high glucose le vels may be largely mediated by endogenous TGF beta.