TUG1 Regulates Pulmonary Arterial Smooth Muscle Cell Proliferation in Pulmonary Arterial Hypertension

BackgroundPulmonary arterial hypertension (PAH) is a progressive disease, characterized by a persistent elevation of pulmonary arterial pressure and pulmonary vascular remodelling. Recent studies implicated that long noncoding RNAs (lncRNAs) play important roles in the development of various diseases. However, the underlying mechanisms of lncRNAs in PAH remain unclear. Here we show evidence for the modulation of human pulmonary smooth muscle cell (HPASMC) proliferation and vascular remodelling by lncRNA taurine upregulated gene1 (TUG1).MethodsTUG1 expression and localization was detected by real-time polymerase chain reaction (PCR) and fluorescence in situ hybridization. Proliferation and apoptosis were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT), western blot, bromodeoxyuridine incorporation, flow cytometry, scratch-wound assay, 4′,6-diamidino-2-phenylindole (DAPI), and caspase-3 activity. Luciferase activity and microscale thermophoresis were used to identify biomolecular interactions. The right ventricular systolic pressure and right ventricular hypertrophy were measured to evaluate cardiopulmonary function.ResultsTUG1 was upregulated in the pulmonary arteries of mice after a hypoxic assault and showed a significant increase in patients with PAH. TUG1 knockdown significantly prevented the development of PAH in vivo. Moreover, TUG1 promoted the proliferative responses of HPASMCs, including cell viability, 5-bromodeoxyuridine incorporation, the expression of proliferating cell nuclear antigen, and cell-cycle progression. All these functions of TUG1 were likely to be associated with miR-328.ConclusionsThe present study indicates that TUG1, a novel potential target for the treatment of PAH, is necessary for HPASMC proliferation and pulmonary vascular remodelling.