Modulation of collagen synthesis in human glomerular epithelial cells by interleukin 1

Human glomerular epithelial cells produce matrix material e.g. collagen type IV. In vitro, the synthesis of collagen can be monitored by the incorporation of 3H-proline, a precursor molecule of the collagens. We report on the enhancement of collagen synthesis by glomerular epithelial cells with highly purified or recombinant I1-1. Since I1-1 is released from monocytes or glomerular mesangial cells by inflammatory mediators, our results point to a participation of I1-1 in the development of sclerosis, which is seen in many forms of chronic inflammatory diseases.