Objectives: Recent evidence has implicated matrix metalloproteinase 2 (MMP-
2) in the pathogenesis of aneurysms. The aim of this study was to examine M
MP-2 production and expression by aortic smooth muscle cells (SMCs) and der
mal fibroblasts derived from patients with abdominal aortic aneurysms (AAAs
).
Methods: Aortic SMCs and dermal fibroblasts were cultured from patients wit
h AAAs or from age-matched controls with atherosclerosis. The production of
MMP and tissue inhibitor of metalloproteinase into culture media was analy
zed with the use of gelatin zymography, Western blotting, and enzyme-linked
immunosorbent assay. Gene expression was analyzed with Northern blotting.
Results: All cells studied constitutively produced MMP-2. Aortic SMCs cultu
red from aneurysmal tissue expressed MMP-2 protein and messenger RNA at a s
ignificantly higher level than SMCs from controls (P = .008). Dermal fibrob
lasts from patients with AAAs expressed MMP-2 at a similar level to control
s. In both cell types, tissue inhibitor of metalloproteinase 2 and membrane
type 1-MMP were expressed at similar levels.
Conclusions: These data suggested that the regulation of MMP-2 gene express
ion was altered in the aortic SMCs of patients with aneurysms, but this fin
ding was not repeated in other mesenchymal tissue.