LAUSR

OBJECTIVE Resveratrol has shown benefit for pulmonary hypertension improvement. Our previous reports showed NR4A3/cyclin D1 pathway promoted pulmonary arterial smooth muscle cells (PASMCs) proliferation. This study tried to explore the mechanism underlying this process, focusing on the role of resveratrol in regulation of miRNA and NR4A3. METHODS Rats were injected with monocrotaline (MCT) to establish pulmonary hypertension (PH) models. Resveratrol was used to prevent pulmonary vascular remodeling. Primary rat PASMCs were cultured in vitro and stimulated by platelet-derived growth factor (PDGF) with or without resveratrol. Cells proliferation and expression of miR-638 as well as NR4A3 were evaluated. RESULTS MCT resulted in significant pulmonary vascular remodeling and down-regulation of miR-638, which could be suppressed by resveratrol. Moreover, PDGF-induced PASMC proliferation and miR-638 down-regulation were both significantly prevented by resveratrol treatment in vitro. MiR-638 mimics markedly inhibited PASMC proliferation and percentage of PCNA-positive cells in vitro. But anti-miR-638 could markedly promote cells proliferation and percentage of PCNA-positive cells. The luciferase reporter assay showed that NR4A3 was a direct target of miR-638. The loss-of-function and gain-of-function experiments indicated that NR4A3 promoted proliferation via cyclin D1 pathway. CONCLUSION Our data indicated that resveratrol prevented MCT-induced pulmonary vascular remodeling via miR-638 regulating NR4A3/cyclin D1 pathway.