Abstract 659: Simvastatin Inhibits Proliferation and Migration of Pulmonary Artery Smooth Muscle Cells from Patients with Idiopathic Pulmonary Arterial Hypertension

Abstract

Background: Idiopathic pulmonary arterial hypertension (IPAH) is a progressive disease characterized by inappropriate increase of pulmonary artery smooth muscle cells (PASMCs) leading to occlusion of pulmonary arterioles and causing pulmonary hypertension. In this study, we assessed the inhibitory effects of simvastatin, an HMG-CoA reductase inhibitor, on proliferation and migration of PASMCs obtained from patients with IPAH. Methods and Results: PASMCs were obtained from 6 patients with IPAH who underwent lung transplantation, and PASMCs were obtained as control cells from 6 patients with bronchogenic carcinoma who underwent lung lobectomy. Platelet-derived growth factor (PDGF) (10 ng/mL) stimulation caused a significantly higher growth rate of PASMCs from patients with IPAH than that of control cells assessed by 3 H-thymidine incorporation ( P< 0.05). Simvastatin at 0.1 Â113>mol/L significantly inhibited PDGF-induced cell proliferation of PASMCs from IPAH patients but did not inhibit proliferation of control cells at the same concentration. Simvastatin at 1 Â113>mol/L also inhibited PDGF-induced migration of PASMCs from IPAH patients assessed by a transwell migration assay ( P< 0.05). Immunofluorescence staining revealed that simvastatin at 1 Â113>mol/L inhibited translocation of Rho A from the cytoplasm to membrane and disorganized actin fibers in PASMCs from IPAH patients. Conclusions: Simvastatin had an inhibitory effect on the inappropriate proliferation and migration of PASMCs from IPAH patients. Simvastatin may be useful for treatment of patients with IPAH.