C-reactive protein induces VCAM-1 gene expression through NF-kappaB activation in vascular endothelial cells.

Recent studies have shown that C-reactive protein (CRP) is not just a predictor of cardiovascular events but also acts directly as a proinflammatory stimulus in vascular cells. In this report, we studied the molecular mechanisms underlying vascular cellular adhesion molecule-1 (VCAM-1) induction by CRP. CRP-induced VCAM-1 mRNA expression and this induction was inhibited by protein kinase C (PKC) inhibitors, p38 mitogen-activated protein kinase (MAPK) inhibitor, and tyrosine kinase inhibitors. In addition, parthenolide, a nuclear factor kappaB (NF-kappaB) inhibitor, abolished VCAM-1 induction. Moreover, CRP increased VCAM-1 promoter activity, indicating that CRP induces VCAM-1 mRNA expression at the transcriptional level. Mutation of NF-kappaB-binding sites resulted in a loss of induction. Finally, an electrophoretic mobility shift assay confirmed binding of the p65 subunit of NF-kappaB to kappaB-binding sites. Taken together, our findings suggest that VCAM-1 induction by CRP is mediated by PKC, p38MAPK, tyrosine kinase and the NF-kappaB-dependent signaling pathways in vascular endothelial cells.