title: Upregulated miR-17 Regulates Hypoxia-Mediated Human Pulmonary Artery Smooth Muscle Cell Proliferation and Apoptosis by Targeting Mitofusin 2.
abstract: BACKGROUND Pulmonary arterial hypertension (PAH) is a fatal disease characterized by impaired regulation of pulmonary artery vascular growth and remodeling. Aberrant expression of miR-17 has been shown to be involved in the pathogenesis of PAH, but its underlying molecular mechanism has not been elucidated. MATERIAL AND METHODS Mitofusin 2 (MFN2) expression was determined by qRT-PCR. The protein expression levels of MFN2, proliferating cell nuclear antigen (PCNA), and pro-apoptotic protein cleaved Caspase-3 were measured using Western blot analysis. Cell proliferation and apoptosis were assessed by CellTiter-Glo reagent and flow cytometry, respectively. Caspase-3/7 activity was measured using an Apo-ONE Homogeneous Caspase-3/7 assay kit. The regulation of miR-17 on MFN2 expression was assessed using luciferase reporter assay system. RESULTS miR-17 expression was upregulated in human pulmonary artery smooth muscle cells (hPASMCs) treated with hypoxia and lung tissues of PAH patients. Inhibition of miR-17 suppressed hypoxia-induced proliferation and promoted apoptosis in hPASMCs. miR-17 inhibited MFN2 expression by binding to its 3'-UTR. Decreased cell viability and increased apoptosis and Caspase-3 activity were observed in the anti-miR-17 + siNC group compared with the anti-miR-NC + siNC group. The expression of cleaved Caspase-3 was upregulated and the expression of PCNA was downregulated in the anti-miR-17 + siNC group. Moreover, these alterations were attenuated by knockdown of MFN2. CONCLUSIONS miR-17 regulates proliferation and apoptosis in hPASMCs through MFN2 modulation. We found that miR-17 acts as a potential regulator of proliferation and apoptosis of hPASMCs, and that it might be developed as a promising new strategy for the treatment of PAH.
authors.affiliation: Department of Cardiovascular Surgery, The Second Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China (mainland).
authors.forename: Zheng
authors.initials: Z
authors.lastname: Lu
authors.affiliation: Department of Geriatric Endocrinology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China (mainland).
authors.forename: Sujun
authors.initials: S
authors.lastname: Li
authors.affiliation: Department of Intensive Care Unit (ICU), The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China (mainland).
authors.forename: Shunxin
authors.initials: S
authors.lastname: Zhao
authors.affiliation: Department of Cardiovascular Surgery, The Second Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China (mainland).
authors.forename: Xianen
authors.initials: X
authors.lastname: Fa
mesh_terms: D020413:3' Untranslated Regions / Q000235:genetics; D017209:Apoptosis / Q000235:genetics; D001483:Base Sequence; D053148:Caspase 3 / Q000378:metabolism; D053179:Caspase 7 / Q000378:metabolism; D015687:Cell Hypoxia; D049109:Cell Proliferation; D015536:Down-Regulation / Q000235:genetics; D020558:GTP Phosphohydrolases / Q000378:metabolism*; D057809:HEK293 Cells; D006801:Humans; D006976:Hypertension, Pulmonary / Q000473:pathology; D008168:Lung / Q000378:metabolism; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D024101:Mitochondrial Proteins / Q000378:metabolism*; D032389:Myocytes, Smooth Muscle / Q000378:metabolism* / Q000473:pathology*; D011651:Pulmonary Artery / Q000473:pathology*; D015854:Up-Regulation / Q000235:genetics*
chemical_list: D020413:3' Untranslated Regions; C524941:MIRN17 microRNA, human; D035683:MicroRNAs; D024101:Mitochondrial Proteins; D053148:Caspase 3; D053179:Caspase 7; D020558:GTP Phosphohydrolases; C470018:MFN2 protein, human