Matrix Metalloproteinase-2 and −9 Differentially Regulate Smooth Muscle Cell Migration and Cell-Mediated Collagen Organization

Abstract

MMP-2 and MMP-9 genetic deficiency decreased by 81% and 65%, respectively (P<0.01), SMC invasion in vitro and decreased formation of intimal hyperplasia in vivo (P<0.01). However, we found that MMP-9, but not MMP-2, was necessary for organization of collagen by SMCs. Likewise, we found that MMP-9 deficiency resulted in a 50% reduction of SMC attachment to gelatin (P<0.01), indicating that SMCs may use MMP-9 as a bridge between the cell surface and matrix. Furthermore, we found that the hyaluronan receptor, CD44, assists in attachment and utilization of MMP-9 by SMCs. Understanding the specific roles of these MMPs, generally thought to be similar, could improve the design of therapeutic interventions aimed at controlling vascular remodeling.