Molecular and Cellular Targets of the MRI Contrast Agent P947 for Atherosclerosis Imaging

作者：Tanja Ouimet, Eric Lancelot, Fabien Hyafil, Mario Rienzo, François Deux, Marjorie Lemaître, Sophie Duquesnoy, Jérôme Garot, Bernard Pierre Roques, Jean‐Baptiste Michel, Claire Corot, Sébastien Ballet · 发表于：Molecular Pharmaceutics · 年份：2012 · DOI：10.1021/mp2003863 · 被引用次数：35 · 研究领域：Protease and Inhibitor Mechanisms、Cerebrovascular and Carotid Artery Diseases、Peptidase Inhibition and Analysis

P947 (DOTA-Gd-peptide) was recently identified as an MRI contrast agent for the detection and characterization of the matrix metalloproteinases (MMP)-rich atherosclerotic plaques. Because this product displays a broad spectrum affinity for the MMP family, we hypothesized that it may also recognize other metalloproteinases overactivated in vulnerable atherosclerotic plaques. Therefore, this study aimed at describing, at the molecular and cellular level, the interactions between P947 and proteases of atherosclerotic plaques. Fluorimetric assays were used to measure the in vitro affinity of P947 toward recombinant and purified MMPs, angiotensin-converting enzyme (ACE), endothelin-converting enzyme (ECE-1), neutral endopeptidase (NEP), and both aminopeptidases A and N (APA and APN). Using similar fluorimetric assays associated with specific substrates, enzymatic activities were measured in vulnerable and stable plaques collected from human atherosclerotic carotid arteries. Ex vivo affinity of P947 for metalloproteinases in vulnerable lesions was subsequently determined. Interaction between P947 and major cell types present in atherosclerotic plaques was also investigated in different cell lines: PMA-1-differentiated THP-1 (macrophage), Ox-LDL-treated THP-1 (foam cell), Jurkat cell line (lymphocyte), and human umbilical vein endothelial cell (HUVEC, endothelial cell). Molecular targeting of P947 was confirmed by fluorimetry, ICP-MS, and in vitro MRI approaches. Potential applicati...