Regulation of Vascular Smooth Muscle Cell Migration and Proliferation In Vitro and in Injured Rat Arteries by a Synthetic Matrix Metalloproteinase Inhibitor

Smooth muscle cell (SMC) migration and proliferation and extracellular matrix remodeling are essential aspects of the arterial response to injury, vessel development, and atherogenesis. Matrix metalloproteinase (MMP) expression is associated with SMC proliferation and migration after arterial injury. To assess the role of MMPs in SMC proliferation and migration and intimal thickening, we measured the effect of the synthetic MMP inhibitor BB94 (Batimastat) on DNA synthesis and migration of SMCs in vitro as well as the formation of a neointima after balloon injury to the rat carotid artery. BB94 dose-dependently inhibited SMC migration induced by platelet-derived growth factor (PDGF)–BB through a filter coated with a thick basement membrane matrix (Matrigel) layer but did not show any inhibitory effect on SMC migration through a lightly coated filter. At concentrations up to 1 μmol/L, BB94 did not alter DNA synthesis induced by PDGF-AA or PDGF-BB. Treatment with 30 mg BB94·kg−1 ·d−1 IP for 7 or 14 days after balloon injury to the rat carotid artery decreased the total number of intimal SMC nuclei and suppressed intimal thickening. SMC proliferation (5-bromo-2′-deoxyuridine labeling) was decreased in the media at 2 days, whereas it was increased in the intima at 7 but not 14 days. These results suggest that BB94 inhibits intimal thickening after arterial injury by decreasing SMC migration and proliferation and support the conclusion that MMPs play a significant role in regulating intimal thickening in injured arteries.