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One of the major problems related to the percutaneous transluminal coronary angioplasty technique is the renarrowing of the vessel, a phenomenon known as restenosis. NO and nonsteroidal anti-inflammatory drugs have been shown to play a role in this pathology. The main problem with the use of conventional NO donors is that they affect blood pressure and flow, and for these reasons, they cannot be used safely in clinical practice. The aim of this study was to evaluate, with the use of a rat model of balloon angioplasty, whether a structural derivative of flurbiprofen, containing an added NO-releasing moiety (HCT-1026), is able to reduce or prevent neointimal formation. Rats were treated for 14 days with equimolar doses of flurbiprofen (2, 7, and 21 mg/kg) or HCT-1026 (3, 10, and 30 mg/kg). After this 14-day treatment, HCT-1026 but not flurbiprofen significantly modified the neointima/media ratio. The reduction in the neointimal proliferation obtained with HCT-1026 was well correlated with an increase in nitrite/nitrate plasma levels and a reduced cell proliferation. Neither HCT-1026 nor flurbiprofen affected inducible NO synthase induction in injured vessels. In conclusion, HCT-1026 caused a significant reduction in restenosis that appears to be directly related to NO release. HCT-1026 may prove to be beneficial in preventing or delaying restenosis in humans.

Objective— We investigated the role of matrix metalloproteinase-8 (MMP8) in neointima formation and in vascular smooth muscle cell (VSMC) migration and proliferation. Approach and Results— After carotid artery wire injuring, MMP8 –/– /apoE –/– mice had fewer proliferating cells in neointimal lesions and smaller lesion sizes. Ex vivo assays comparing VSMCs isolated from MMP8 knockout and wild-type mice showed that MMP8 knockout decreased proliferation and migration. Proteomics analysis revealed that a disintegrin and metalloproteinase domain–containing protein 10 (ADAM10) had lower concentrations in MMP8 knockout VSMC culture media than in MMP8 wild-type VSMC culture media. Western blot, flow cytometric, and immunocytochemical analyses showed that MMP8 knockout VSMCs contained more pro-ADAM10 but less mature ADAM10, more N-cadherin, and β-catenin in the plasma membrane but less β-catenin in the nucleus and less cyclin D1. Treatment of MMP8 wild-type VSMCs with an ADAM10 inhibitor, GI254023X, or siRNA knockdown of ADAM10 in MMP8 wild-type VSMCs inhibited proliferation and migration, increased N-cadherin and β-catenin in the plasma membrane, reduced β-catenin in the nucleus, and decreased cyclin D1 expression. Incubation of MMP8 knockout VSMCs with a recombinant ADAM10 rescued the proliferative and migratory ability of MMP8 knockout VSMCs and increased cyclin D1 expression. Furthermore, immunohistochemical analyses showed colocalization of ADAM10 with VSMCs and N-cadherin, and nuclear accumulation of β-catenin in the neointima in apoE –/– /MMP8 +/+ mice. Conclusions— MMP8 enhances VSMC proliferation via an ADAM10, N-cadherin, and β-catenin–mediated pathway and plays an important role in neointima formation.