Interferon-gamma modulates messenger RNA levels of c-sis (PDGF-B chain), PDGF-A chain, and IL-1 beta genes in human vascular endothelial cells.

The authors have investigated the effects of cytokines and lipopolysaccharide (LPS) on mRNA levels of c-sis (platelet-derived growth factor (PDGF)-B chain), PDGF-A chain, and interleukin 1 beta (IL-1 beta) genes in human vascular endothelial cells (EC). IL-1, tumor necrosis factor (TNF), and LPS not only enhanced the accumulation of c-sis mRNA, but also induced IL-1 beta gene expression. Interferon-gamma (IFN-gamma), in contrast, suppressed the accumulation of c-sis mRNA profoundly and PDGF-A chain mRNA to a lesser extent. The cytokine, in addition, suppressed the release of PDGF-like proteins by EC, while maintaining the growth of EC. IFN-gamma, however, augmented the levels of IL-1 beta mRNA in cultured EC in association with LPS or IL-1, suggesting that the suppression of c-sis expression was not mediated through modulation of IL-1 gene expression by IFN-gamma. These results raise the possibility that IFN-gamma may play a novel regulatory role in the pathogenesis of vascular diseases such as atherosclerosis and vasculitis.