LncRNA PART1 Regulates STAT3 Expression To Mediate Hypoxia-Induced Proliferation Of Rat Pulmonary Artery Smooth Muscle Cells

BackgroundPulmonary hypertension is a group of severe cardiovascular and pulmonary disease syndromes caused by increased pulmonary circulation pressure and increased pulmonary vascular resistance.Pulmonary smooth muscle cell proliferation has been shown to be one of the important mechanisms of hypoxic pulmonary hypertension.At present,many studies have demonstrated that molecules involved in the development of pulmonary hypertension also contain long non-coding Rnas.ObjectiveThe purpose of this study was to investigate the role of LncRNA PART1 in hypoxy-induced PASMCs proliferation in rats and whether it induced PASMCs proliferation through hypoxia mediated by STAT3 regulation.MethodsIn this research,primary-cultured pulmonary artery smooth muscle cells extracted from SPF grade Sprague-Dawley male rats were selected as the cell model cultured in vitro.After identification by passage and immunocytochemical staining,the pulmonary artery smooth muscle cells of rats were placed in the corresponding culture environment at21%,10%,5%,3% and 1% oxygen concentrations.After 0,4,8,12,24,and 48 hours,the proliferation of pulmonary artery smooth muscle cells of rats was detected by CCK-8.WB and RT-qPCR were used to detect and validate the experimental conditions of the study molecules in the construction of hypoxic-induced rat pulmonary artery smooth muscle cell proliferation model.The expression of LncRNA PART1 and STAT3 in PASMCs of rats in hypoxia and normal-oxygen groups was detected by RT-qPCR and WB,which proved that there were differences in the expression of PASMCs between hypoxia and normal-oxygen groups.The overexpression plasmid and si RNA of LncRNA PART1 and STAT3 were transfected into rat PASMCs,and the proliferation level of rat pulmonary artery smooth muscle cells was detected by CCK-8,to verify the effect of LncRNA PART1 and STAT3 on the proliferation of rat pulmonary artery smooth muscle cells under hypoxia condition.ResultsThe primary rat pulmonary artery smooth muscle cells grew well and were confirmed as smooth muscle cells by immunocytochemical staining.After 0,12,24,48 and 72 hours of treatment with different oxygen concentrations,the proliferation of PASMCs in rats was significantly enhanced by CCK-8 and MTT method(P<0.05).The gradient test of HIF-1α,STAT3 and LncRNA PART1 determined 24 h as the intervention time point.In the follow-up experiment,the hypoxic-induced pulmonary artery smooth muscle cell proliferation model of rats was constructed by treating with 1% oxygen concentration for 24 hours.The expression of STAT3 in PASMCs of rats was respectively overexpressed and silenced.After CCK-8 and MTT detection,the proliferation of pulmonary artery smooth muscle cells of rats in the STAT3-overexpressed group was significantly enhanced,while that in the silenced group was significantly weakened.LncRNA PART1 in pulmonary artery smooth muscle cells of rats was respectively overexpressed and silenced,and the expression of STAT3 in PASMCs of rats in the overexpressed LncRNA PART1 group was significantly up-regulated,while the expression of STAT3 in the silenced group was significantly reduced.The overexpression of LncRNA PART1 can promote the proliferation of PASMCs in hypoxia.Finally,we determined that LncRNA PART1 could mediate PASMCs proliferation in rats by regulating STAT3.ConclusionIn conclusion,hypoxia can promote the proliferation of pulmonary artery smooth muscle cells.During this process,LncRNA PART1 plays a positive regulatory role and can affect PASMCs proliferation in rats by regulating the expression of STAT3.