Interleukin 6 modulates c-sis gene expression in cultured human endothelial cells

Human vascular endothelial cells secrete platelet-derived growth factor (PDGF)-like polypeptides which may mediate some of the vascular effects in the inflammatory process. We have demonstrated that IL-6 caused a significant increase in the mRNA level of the c-sis gene (PDGF B chain) in cultured human endothelial cells. IL-1 alpha and IL-1 beta also increased c-sis mRNA transcripts after an extended incubation period and both cytokines acted synergistically with IL-6 in increasing c-sis expression. Tumor necrosis factor enhanced the accumulation of c-sis mRNA and interferon-gamma decreased its level. In the inflammatory process specific cytokines can modulate c-sis expression in human endothelial cells. Their subsequent production of PDGF-like polypeptides could stimulate cell migration and proliferation, and cause the release of vascular inflammatory mediators.