Dose-Dependent Modulation of Tissue Factor Protein and Procoagulant Activity in Human Monocyte-Derived Macrophages by Oxidized Low Density Lipoprotein
Year: 2011
Type: article
Abstract: AIM: Oxidized low-density lipoprotein (oxLDL) interacts with macrophages and is implicated in atherogenesis. Macrophages are also the major source within the atherosclerotic plaque of tissue factor (TF), the membrane-bound glycoprotein receptor that triggers the coagulation cascade in vivo and contributes to plaque thrombogenicity. In this study we tested the hypothesis that oxLDL modulates TF expression in human monocyte-derived macrophages (MDMs). METHODS: Mononuclear cells were isolated from human blood, allowed to differentiate into MDMs during 8 days in cell culture, and then exposed to varying concentrations of oxLDL in the presence or absence of lipopolysaccharide (LPS). TF procoagulant activity (TF-PCA) of MDMs was measured by one-stage recalcification clotting assay using human recombinant TF as standard. TF protein was evaluated by Western blotting, and TF mRNA was determined by Northern blot analysis. RESULTS: OxLDL at 5-10 µg/mL increased TF-PCA, TF protein, and mRNA in MDMs, whereas 20-100 µg/mL oxLDL inhibited TF-PCA, protein expression, and mRNA expression in these cells even in the face of LPS stimulation. CONCLUSIONS: Low concentrations of oxLDL enhance TF expression in MDMs, whereas higher concentrations attenuate TF expression both at baseline as well as following LPS stimulation. Both TF-PCA and TF protein follow this dose-response pattern that is preceded by concordant mRNA changes. Thus, we have demonstrated modulation by oxLDL of TF protein and bioactivity in MDMs.
DOI: 10.5551/jat.7179
Authors: Simcha Ron Meisel, Xiao-Ping Xu, Thomas Scott Edgington, Bojan Cercek, John Ong, Sanjay Kaul, Prediman Krishan Shah
Institution: Scripps Research Institute
Language: English
Subfield: Hematology
Field: Medicine
Domain: Health Sciences
Open Access status: hybrid
OpenAlex ID: W2072634622