MiR-18a-5p contributes to enhanced proliferation and migration of PASMCs via targeting Notch2 in pulmonary arterial hypertension.

This study is undertaken to investigate the role and molecular mechanisms of miR-18a-5p in regulating pulmonary arterial hypertension (PAH) pathogenesis. Gene expression and protein levels were determined by qRT-PCR and western blot, respectively; Cell counting kti-8 and Transwell migration assays were used to determine the biological functions of miR-18a-5p in pulmonary arterial smooth muscle cells (PASMCs); bioinformatics analysis, luciferase reporter assays were used to elucidate the mechanisms of miR-18a-5p. MiR-18a-5p was up-regulated in the clinical samples from PAH patients. PASMCs treated with hypoxia exhibited enhanced proliferative ability and upregulated miR-18a-5p expression. Knockdown of miR-18a-5p attenuated hypoxia-induced hyper-proliferation and enhanced migratory potential of PASMCs; while miR-18a-5p overexpression promoted PASMC proliferation and migration. Further mechanistic studies showed that Notch2 was a direct target of miR-18a-5p and was repressed by miR-18a-5p overexpression. The rescue studies indicated that Notch2 overexpression counteracted the enhanced proliferation and migration induced by miR-18a-5p mimics in PASMCs. Similarly, Notch2 overexpression also block the effects caused by hypoxia in PASMCs. Moreover, Notch2 expression was down-regulated in the PAH patients and was negatively correlated with miR-18a-5p expression. In vivo animal studies further revealed the up-regulation of miR-18a-5p and the down-regulation of Notch2 in the PAH rats. Collectively, this study identified the up-regulated miR-18a-5p in the PAH patients; our data suggest that miR-18a-5p contributes to the enhanced proliferation and migration of PASMCs via repressing Notch2 expression.

Miao R ，Liu W ，Qi C ，Song Y ，Zhang Y ，Fu Y ，Liu W ，Lang Y ，Zhang Y ，Zhang Z ... -  《-》

miR-143 and miR-145 promote hypoxia-induced proliferation and migration of pulmonary arterial smooth muscle cells through regulating ABCA1 expression.

Excessive proliferation and migration of pulmonary artery smooth muscle cells (PASMCs) play an important role in the occurrence and development of pulmonary arterial hypertension (PAH). miR-143/145 was reported to be up-regulated in the animal models and PAH patients, and deletion of miR-143/145 cluster prevented the development of hypoxia-induced pulmonary hypertension, but its underlying mechanism has not been elucidated. qRT-PCR and Western blot were performed to detect the expressions of miR-143/145 and ATP-binding cassette transporter A1 (ABCA1) in PAH patients and PASMCs under hypoxic conditions. Cell proliferation and migration were assessed by Cell Counting Kit-8 and wound-healing assay, respectively. Luciferase reporter assay and RNA immunoprecipitation were conducted to confirm the interaction between miR-143/145 and ABCA1. Hypoxia-induced PAH rat model was established to confirm the functions of miR-143/145 in the pathogenesis of PAH and its underlying mechanism in vivo. miR-143 and miR-145 were up-regulated and ABCA1 was down-regulated in PAH patients and PASMCs under hypoxic conditions for different time, as well as hypoxia-induced PAH rats. miR-143/145 inhibition and ABCA1 overexpression suppressed hypoxia-induced proliferation and migration in PASMCs. ABCA1 was identified as a direct target of miR-143/145 in PASMCs. Moreover, ABCA1 partially reversed miR-143/145-mediated promotion of hypoxia-induced cell proliferation and migration in PASMCs. Furthermore, in vivo experiments confirmed that inhibition of miR-143/145 prevents hypoxia-induced pulmonary hypertension and pulmonary vascular remodeling by targeting ABCA1. miR-143/145 promoted hypoxia-induced proliferation and migration of PASMCs by targeting ABCA1, contributing to better understanding of the mechanism underlying the pathogenesis of PAH.

Yue Y ，Zhang Z ，Zhang L ，Chen S ，Guo Y ，Hong Y ... -  《-》

Human pulmonary artery smooth muscle cell dysfunction is regulated by miR-509-5p in hypoxic environment.

Wang J ，Jiang R ，Tan Y ，Cheng K ... -  《-》

MicroRNA-140-5p targeting tumor necrosis factor-α prevents pulmonary arterial hypertension.

Pulmonary arterial hypertension (PAH) is characterized by the apoptosis resistance and hyperproliferation of pulmonary artery smooth muscle cells (PASMCs). Its pathogenesis has not been revealed. Here, we carried out experiments to investigate the functions of miR-140-5p and tumor necrosis factor-α (TNF-α). We selected GSE703 from Gene Expression Omnibus (GEO) Database to conduct microarray analysis using R software and Gene Set Enrichment Analysis (GSEA). Combing bioinformatics results, the upregulation of miR-140-5p inhibited PAH progression through targeting TNF-α. RNA expression was measured by quantitative real-time polymerase chain reaction (RT-qPCR) and protein level was measured by western blot analysis and enzyme-linked immunosorbent assays (ELISA). We conducted monocrotaline (MCT) injection to rats to form PAH animal models. The lung tissues were observed by hematoxylin-eosin (HE) staining and Sirius red-picric acid staining. Right ventricular systolic pressure (RVSP) and the ratio of right ventricle (RV)-to-left ventricle (LV) plus septum (S) weight (RV/[LV + S]) were measured in MCT-induced animal models. Overexpression of miR-140-5p and TNF-α were utilized to research the proliferation, migration, and phenotypic variation of hypoxia-mediated PASMCs. The binding between miR-140-5p and TNF-α 3'-untranslated region (3'-UTR) was confirmed via luciferase reporter assay. Downregulation of miR-140-5p and upregulation of TNF-α were observed in PAH rat model and hypoxia-mediated PASMCs. And we proved that overexpression of miR-140-5p could suppress the proliferation, migration, and phenotypic variation of PASMCs, therefore inhibiting PAH pathogenesis. Luciferase assay verified that miR-140-5p targeted TNF-α directly. A converse correlation was also shown between miR-140-5p and TNF-α in PASMCs. miR-140-5p and TNF-α are important regulators in PAH pathology and may serve as a therapeutic target for PAH.

Zhu TT ，Zhang WF ，Yin YL ，Liu YH ，Song P ，Xu J ，Zhang MX ，Li P ... -  《-》

MiR-593-5p promotes the development of hypoxic-induced pulmonary hypertension via targeting PLK1.

Zhao TF ，Wang SY ，Zou XZ ，Zhao HD ... -  《-》