C-reactive protein induces matrix metalloproteinase-1 and-10 in human endothelial cells -: Implications for clinical and subclinical atherosclerosis

OBJECTIVES We examined the effect of C-reactive protein (CRP) on matrix metalloproteinase (MMP) and inhibitor expression in endothelial cells and in patients with clinical and subclinical atherosclerosis. BACKGROUND In addition to predicting atherosclerotic vascular disease, CRP may directly promote a proinflammatory/proatherosclerotic phenotype. METHODS Human umbilical vein endothelial cells (HUVECs) and aortic endothelial cells (HAECs) were incubated in the presence or absence of CRP (50 mu g/ml). Microarray analysis, real-time polymerase chain reaction, immunological and activity assays for MMPs were performed. Specific inhibitors of mitogen-activated protein kinase pathway were used. The MMP-1 and -10 plasma levels were measured in apparently healthy subjects (n = 70). Immunolocalization of CRP, MMP-1, and MMP-10 was performed in human mammary arteries and carotid endarterectomy specimens. RESULTS C-reactive protein augmented MMP-1 and -10 messenger ribonucleic acid expression in HUVEC (p < 0.05) and HAEC (p < 0.01). C-reactive protein simulation also increased MMP-1 and -10 protein in conditioned culture medium (p < 0.001), as well as MMP activity (p = 0.001). Specific inhibition of p38 or MEK abolished the CRP induction of the MMP-1, whereas MMP-10 induction blockade required the simultaneous inhibition of p38 and Jun N-terminal kinase pathways. Subjects with CRP values > 3 mg/l (n = 37) had increased plasma MMP-1 and -10 (p < 0.05), the association being significant after adjustment for confounding variables (p = 0.04 and p = 0.008, respectively). The MMP-10 levels were elevated in subjects with higher carotid intima-media thickness (p = 0.009). Increased CRP and MMP-10 colocalized in endothelial layer and macrophage-rich areas in advanced atherosclerotic plaques. CONCLUSIONS Increased local and systemic CRP-related MMP activation might provide a link between inflammation and plaque vulnerability.