OBJECTIVE: Constrictive remodeling accounts for lumen loss in postangioplasty restenosis. Matrix metalloproteinase-9 (MMP-9) has been shown to prevent constrictive remodeling in vivo. To investigate potential mechanisms for this observation, we investigated the role of MMP-9 in smooth muscle cell (SMC)-mediated collagen gel contraction, an in vitro model of constrictive remodeling. METHODS: Fischer rat SMCs were stably transfected with a construct-expressing rat-MMP-9 under the control of a tetracycline (Tet)-off promoter. SMCs were seeded in type I collagen gels (2.4 mg/ml) in the presence or not of tetracycline (1 microg/ml), and gel contraction was defined as the percentage of retraction of the collagen gel. The depletion of MMP-9 was obtained by using siRNA targeting MMP-9 mRNA or a blocking antibody. RESULTS: Gel contraction was significantly reduced at all times when MMP-9 was overexpressed (Tet-) as compared with the control condition (Tet+). However, MMP-9 depletion of control (Tet+) SMCs (using siRNA or antibody) also inhibited gel contraction. To resolve the apparent discrepancy and determine if MMP-9 exerts a dose-dependent biphasic effect on gel contraction, conditioned medium and purified rat-MMP-9 were prepared. Gel contraction was significantly increased by addition of 0.8 ng/ml of MMP-9, while high concentrations of MMP-9 (> or =100 ng/ml) inhibited contraction. The addition of BB94 and TIMP-1 did not alter the inhibitory or stimulatory effect of MMP-9. CONCLUSIONS: Our data suggest that MMP-9, independent of its proteolytic function, has a biphasic effect on SMC-mediated collagen gel contraction. Understanding the different roles of MMP-9 should allow the development of better therapeutic strategies for restenotic vascular disease.
OBJECTIVE: Constrictive remodeling accounts for lumen loss in postangioplasty restenosis. Matrix metalloproteinase-9 (MMP-9) has been shown to prevent constrictive remodeling in vivo. To investigate potential mechanisms for this observation, we investigated the role of MMP-9 in smooth muscle cell (SMC)-mediated collagen gel contraction, an in vitro model of constrictive remodeling. METHODS: Fischer rat SMCs were stably transfected with a construct-expressing rat-MMP-9 under the control of a tetracycline (Tet)-off promoter. SMCs were seeded in type I collagen gels (2.4 mg/ml) in the presence or not of tetracycline (1 microg/ml), and gel contraction was defined as the percentage of retraction of the collagen gel. The depletion of MMP-9 was obtained by using siRNA targeting MMP-9 mRNA or a blocking antibody. RESULTS: Gel contraction was significantly reduced at all times when MMP-9 was overexpressed (Tet-) as compared with the control condition (Tet+). However, MMP-9 depletion of control (Tet+) SMCs (using siRNA or antibody) also inhibited gel contraction. To resolve the apparent discrepancy and determine if MMP-9 exerts a dose-dependent biphasic effect on gel contraction, conditioned medium and purified rat-MMP-9 were prepared. Gel contraction was significantly increased by addition of 0.8 ng/ml of MMP-9, while high concentrations of MMP-9 (> or =100 ng/ml) inhibited contraction. The addition of BB94 and TIMP-1 did not alter the inhibitory or stimulatory effect of MMP-9. CONCLUSIONS: Our data suggest that MMP-9, independent of its proteolytic function, has a biphasic effect on SMC-mediated collagen gel contraction. Understanding the different roles of MMP-9 should allow the development of better therapeutic strategies for restenotic vascular disease.
Authors: I M Loftus; S Goodall; M Crowther; L Jones; P R Bell; A R Naylor; M M Thompson Journal: Ann N Y Acad Sci Date: 1999-06-30 Impact factor: 5.691
Authors: Taher Nassar; Abdullah Haj-Yehia; Sa'ed Akkawi; Alice Kuo; Khalil Bdeir; Andrew Mazar; Douglas B Cines; Abd Al-Roof Higazi Journal: J Biol Chem Date: 2002-08-08 Impact factor: 5.157
Authors: Yuji Naito; Misty Williams-Fritze; Daniel R Duncan; Spencer N Church; Narutoshi Hibino; Joseph A Madri; Jay D Humphrey; Toshiharu Shinoka; Christopher K Breuer Journal: Cells Tissues Organs Date: 2011-10-12 Impact factor: 2.481
Authors: Lisa Cm Dahl; Zeyad Nasa; JieYu Chung; Be'eri Niego; Volga Tarlac; Heidi Ho; Adam Galle; Steven Petratos; Jae Young Lee; Frank Alderuccio; Robert L Medcalf Journal: PLoS One Date: 2016-07-18 Impact factor: 3.240