Abstract
The factors which regulate mesangial cell growth are of importance in determining the cellular lesions of nephritis. In this communication, we report that transforming growth factor-beta (TGF-beta) exerts a suppressive effect on mesangial cell 3H-thymidine uptake. Furthermore, TGF-beta antagonizes the mitogenic effect of epidermal growth factor (EGF) on DNA synthesis. The concomitant presence of TGF-beta in the cell cultures is not required for its effect since cells pretreated with the substance and rinsed of it showed suppressed 3H-thymidine uptake and did not respond to EGF. The effect of TGF-beta can also be demonstrated on cells committed to proliferate by the prior addition of EGF. The results of the study have relevance to the mechanisms underlying the histologic lesions of immune-mediated nephritis.