Atherosclerotic arterial remodeling and the localization of macrophages and matrix metalloproteases 1, 2 and 9 in the human coronary artery

Atherosclerotic luminal narrowing is determined by plaque mass and the mode of geometrical remodeling. Recently, we reported that the type of atherosc lerotic remodeling is associated with the presence of histological markers for plaque vulnerability. Inflammation and matrix degrading proteases (MMPs ) may play a role in both plaque vulnerability and in expansive arterial re modeling. The aim of the present study was to investigate the association b etween the remodeling mode and the localization of macrophages and MMPs in coronary atherosclerotic segments. From 36 atherosclerotic coronary arterie s, 45 and 51 segments were selected with a vessel area that was > 10% small er and larger compared with the adjacent segments, respectively. No signifi cant difference in staining for macrophages was observed between segments w ith expansive and constrictive remodeling. More MMP-2 and MMP-9 staining wa s observed in plaques of expansively remodeled segments compared with const rictively remodeled segments. In general, MMP-staining was less evident in the adventitial layer compared with the plaque. Zymography revealed more ac tive MMP-2 in expansively remodeled segments compared with constrictively r emodeled segments (340 +/- 319 vs. 199 +/- 181 (adjusted counts/mm(2)), res pectively, P = 0.019). Zymography did not show differences in inactive MMP- 2 or MMP-9 among groups. It might be postulated that MMPs within the plaque play a causal role not only in plaque vulnerability but also in de novo at herosclerotic remodeling. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.