thromboplastin and acetovanillone

Tissue factor (TF), the main trigger of coagulation cascade, is a major component of the atherosclerotic plaque. Matrix metalloproteinases (MMPs) are recognized as key mediators of extracellular matrix remodeling during inflammation. It was recently emphasized that both TF and MMP-9 were overexpressed in atherosclerotic plaques, suggesting a role of both molecules in plaque instability and thrombogenicity.. The present study was designed to determine whether human monocytes could co-express TF and MMP-9 when the cells interact with type I collagen, a major component of the extracellular matrix and atherosclerotic plaque.. Human monocytes were isolated by elutriation and incubated in collagen I-coated plates. Tissue factor and MMP-9 expression were examined using real-time reverse transcription-polymerase chain reaction, flow cytometry, western blot and zymography. The activation of nuclear factor-kappa B (NF-kappaB) and the role of reactive oxygen species (ROS) in TF and MMP-9 production was studied using gel shift experiments, antioxidants pyrrolidine dithiocarbamate (PDTC) and N-acetyl-cysteine (NAC), and apocynin (a specific inhibitor of the NADPH oxidase).. Type I collagen induced TF expression and increased MMP-9 production. In addition, the pro-inflammatory tumor necrosis factor-alpha (TNF-alpha), produced in response to collagen I, increased MMP-9 production. PDTC and NAC inhibited NF-kappaB activation during monocyte interaction with collagen I. Finally, both antioxidants and apocynin decreased the expression of TF, TNF-alpha, and MMP-9.. These results indicate a new mechanism in the monocyte expression of TF and MMP-9 in response to collagen I involving a ROS-dependent pathway linked to the activation of the NADPH oxidase.

Topics: Acetophenones; Acetylcysteine; Base Sequence; Blotting, Western; Cells, Cultured; Collagen Type I; Cytokines; DNA Primers; Electrophoretic Mobility Shift Assay; Enzyme-Linked Immunosorbent Assay; Flow Cytometry; Humans; Matrix Metalloproteinase 9; Monocytes; NF-kappa B; Oxidation-Reduction; Pyrrolidines; Reactive Oxygen Species; Reverse Transcriptase Polymerase Chain Reaction; Thiocarbamates; Thromboplastin