Paradigmatic identification of MMP-2 and MT1-MMP activation systems in cardiac fibroblasts cultured as a monolayer

✍ Scribed by Chun Guo; Juwei Jiang; J. Martin Elliott; Lucia Piacentini

• Book ID: 102300338
• Publisher: John Wiley and Sons
• Year: 2005
• Tongue: English
• Weight: 284 KB
• Volume: 94
• Category: Article
• ISSN: 0730-2312
• DOI: 10.1002/jcb.20272

✦ Synopsis

Abstract

Activations of MMP‐2 and membrane type 1‐matrix metalloproteinase (MT1‐MMP) have been correlated with cell migration, a key cellular event in the wound healing and tissue remodeling. We have previously demonstrated furin‐dependent MMP‐2 and MT1‐MMP activations induced by type I collagen in cardiac fibroblasts. To understand mechanistic aspects of the regulation of MMP‐2 and MT1‐MMP activations by potential non‐matrix factor(s) in cardiac fibroblasts, in the present study, we examined the effects of various agents including concanavalin A (ConA), a proteolytic phenotype‐producing agent. We showed that treatment of cells with ConA activated pro‐MMP‐2, and that this activation concurred with elevated levels of cellular MT1‐MMP and TIMP‐2. The presence of active MT1‐MMP and 43 and 36 kDa processed forms of MT1‐MMP in a fraction of intracellular proteins prepared from ConA‐treated cells suggests the possible internalization of differential forms of MT1‐MMP. The appearance of 36 kDa processed form of MT1‐MMP in conditioned media prepared from ConA‐treated cells indicates the possible extracellular release of the further processed MT1‐MMP fragment. Inhibition of furin in ConA‐treated cells attenuated pro‐MT1‐MMP processing and the cellular TIMP‐2 level, plus it reduced cell‐released active MMP‐2 in a time‐dependent manner. These results suggest the involvement of furin in the ConA‐induced activations of MT1‐MMP and MMP‐2. Furthermore, the existence of furin inhibitor‐insensitive pro‐ and active MMP‐2 species associated with ConA‐treated cells implies that a mechanism independent of furin may perhaps account for the binding of the MMP‐2 species to the cells. Supplementary material for this article can be found at http://www.mrw.interscience.wiley.com/suppmat/0730‐2312/suppmat/94/suppmat_guo.tif. © 2004 Wiley‐Liss, Inc.