title: MiR-140-5p regulates hypoxia-mediated human pulmonary artery smooth muscle cell proliferation, apoptosis and differentiation by targeting Dnmt1 and promoting SOD2 expression.
abstract: miR-140-5p is down-regulated in patients with pulmonary arterial hypertension (PAH) and experimental models of PAH, and inhibits hypoxia-mediated pulmonary artery smooth muscle cell (PASMC) proliferation in vitro. Delivery of synthetic miR-140-5p prevents and treats established, experimental PAH. DNA methyltransferase 1 (Dnmt1) is up-regulated in PAH associated human PASMCs (HPASMCs), which promotes the development of PAH by hypermethylation of CpG islands within the promoter for superoxide dismutase 2 (SOD2) and down-regulating SOD2 expression. We searched for miR-140-5p targets using TargetScan, PicTar and MiRanda tools, and found that Dnmt1 is a potential target of miR-140-5p. Based on these findings, we speculated that miR-140-5p might target Dnmt1 and regulate SOD2 expression to regulate hypoxia-mediated HPASMC proliferation, apoptosis and differentiation. We detected the expression of miR-140-5p, Dnmt1 and SOD2 by quantitative real-time polymerase chain reaction (qRT-PCR) and western blot assays, respectively, and found down-regulation of miR-140-5p and SOD2 and up-regulation of Dnmt1 exist in PAH tissues and hypoxia-mediated HPASMCs. Cell proliferation, apoptosis and differentiation detection showed that miR-140-5p inhibits proliferation and promotes apoptosis and differentiation of HPASMCs in hypoxia, while the effect of Dnmt1 on hypoxia-mediated HPASMCs is reversed. Luciferase assay confirmed that miR-140-5p targets Dnmt1 directly. An inverse correlation is also found between miR-140-5p and Dnmt1 in HPASMCs. In addition, we further investigated whether miR-140-5p and Dnmt1 regulate HPASMC proliferation, apoptosis and differentiation by regulating SOD2 expression, and the results confirmed our speculation. Taken together, these results indicated that miR-140-5p at least partly targets Dnmt1 and regulates SOD2 expression to inhibit proliferation and promote apoptosis and differentiation of HPASMCs in hypoxia.
authors.affiliation: Department of Cardiac Surgery, the First Affiliated Hospital of Zhengzhou University, PR China.
authors.forename: Yanwei
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Cardiac Surgery, the First Affiliated Hospital of Zhengzhou University, PR China. Electronic address: xujingdoc@163.com.
authors.forename: Jing
authors.initials: J
authors.lastname: Xu
mesh_terms: D017209:Apoptosis; D001483:Base Sequence; D002454:Cell Differentiation; D015687:Cell Hypoxia; D002460:Cell Line; D049109:Cell Proliferation; D000076123:DNA (Cytosine-5-)-Methyltransferase 1; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000378:metabolism*; D005786:Gene Expression Regulation; D006801:Humans; D006976:Hypertension, Pulmonary / Q000378:metabolism; D008168:Lung / Q000378:metabolism; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D009130:Muscle, Smooth / Q000166:cytology; D032389:Myocytes, Smooth Muscle / Q000166:cytology*; D011651:Pulmonary Artery / Q000166:cytology*; D013482:Superoxide Dismutase / Q000378:metabolism*; D014162:Transfection; D015854:Up-Regulation; D000099156:Superoxide Dismutase 2
chemical_list: D000076123:DNA (Cytosine-5-)-Methyltransferase 1; D004248:DNA (Cytosine-5-)-Methyltransferases; D035683:MicroRNAs; D013482:Superoxide Dismutase; D000099156:Superoxide Dismutase 2; C544302:Mirn140 microRNA, human; C000619380:DNMT1 protein, human
keywords: DNA methyltransferase 1; Pulmonary arterial hypertension; Superoxide dismutase 2; miR-140-5p