Sodium Azide in Commercially Available C-Reactive Protein Preparations Does Not Influence Matrix Metalloproteinase-2 Synthesis and Release in Cultured Human Aortic Vascular Smooth Muscle Cells

Detection of circulating concentrations of the acute-phase reactant C-reactive protein (CRP), which is synthesized in response to proinflammatory cytokines, is a relevant tool for identifying the involvement of low-grade inflammation in atherosclerosis and for predicting future atherothrombotic events (1). Whether CRP is only a marker or is also an active player in atherosclerotic injury is a matter of intense debate (2). CRP is present in atherosclerotic lesions (3) and can contribute directly to atherothrombosis (4). In particular, CRP induces expression of proatherogenetic molecules in endothelial cells and promotes LDL uptake by macrophages (4). We recently observed that CRP increases synthesis and secretion of matrix metalloproteinase 2 (MMP-2) from cultured human vascular smooth muscle cells (hVSMCs) (5), a mechanism potentially involved in plaque destabilization. Recently, however, the reliability of results concerning CRP obtained in vitro has been …