Fibrinopeptide A induces C‐reactive protein expression through the ROS‐ERK1/2/p38‐NF‐κB signal pathway in the human umbilical vascular endothelial cells

: Atherosclerosis is a chronic inflammatory disease of the arterial wall. Inflammation causes endothelial injury and dysfunction, which is an initial step of atherosclerosis. Fibrinopeptide A (FPA) is a biomarker of the activation of the coagulation system, and a high concentration of FPA in the blood occurs in patients with ischemic cardiocerebrovascular diseases. The present research observed that FPA stimulated the generation of C-reactive protein (CRP), IL-1β, and IL-6 in human umbilical vascular endothelial cells (HUVECs); and anti-IL-1 β and anti-IL-6 neutralizing antibodies did not alter FPA-induced CRP expression in HUVECs. The subchronic administration of FPA into rats increased the plasma FPA and CRP levels. Further studies showed that FPA stimulated superoxide anion generation, activated ERK1/2 and p38, promoted nuclear factor κB (NF-κB) nuclear translocation, and raised the NF-κB level in the nuclei of HUVECs. Antioxidant N-acetylcysteine (NAC), complex II inhibitor thenoyltrifluoroacetone (TTFA), and NADPH oxidase inhibitor diphenyleneiodonium (DPI) inhibited FPA-stimulated generation of superoxide anion, and NAC reduced FPA-induced expressions of the phosphorylated ERK1/2 and p38. NAC, TTFA, DPI, inhibitors of ERK1/2, p38, and NF-κB all downregulated FPA-induced CRP expression. These results indicate that FPA induces CRP expression in HUVECs via the ROS-ERK1/2/p38-NF-κB signal pathway. Moreover, this is the first report that FPA produces a proinflammatory effect on the vascular endothelial cells.