title: MicroRNA-138 and MicroRNA-25 Down-regulate Mitochondrial Calcium Uniporter, Causing the Pulmonary Arterial Hypertension Cancer Phenotype.
abstract: BACKGROUND
  Pulmonary arterial hypertension (PAH) is an obstructive vasculopathy characterized by excessive pulmonary artery smooth muscle cell (PASMC) proliferation, migration, and apoptosis resistance. This cancer-like phenotype is promoted by increased cytosolic calcium ([Ca2+]cyto), aerobic glycolysis, and mitochondrial fission.
  
  
  OBJECTIVE
  To determine how changes in mitochondrial calcium uniporter (MCU) complex (MCUC) function influence mitochondrial dynamics and contribute to PAH's cancer-like phenotype.
  
  
  METHODS
  PASMCs were isolated from patients with PAH and healthy control subjects and assessed for expression of MCUC subunits. Manipulation of the pore-forming subunit, MCU, in PASMCs was achieved through small interfering RNA knockdown or MCU plasmid-mediated up-regulation, as well as through modulation of the upstream microRNAs (miRs) miR-138 and miR-25. In vivo, nebulized anti-miRs were administered to rats with monocrotaline-induced PAH.
  
  
  RESULTS
  Impaired MCUC function, resulting from down-regulation of MCU and up-regulation of an inhibitory subunit, mitochondrial calcium uptake protein 1, is central to PAH's pathogenesis. MCUC dysfunction decreases intramitochondrial calcium ([Ca2+]mito), inhibiting pyruvate dehydrogenase activity and glucose oxidation, while increasing [Ca2+]cyto, promoting proliferation, migration, and fission. In PAH PASMCs, increasing MCU decreases cell migration, proliferation, and apoptosis resistance by lowering [Ca2+]cyto, raising [Ca2+]mito, and inhibiting fission. In normal PASMCs, MCUC inhibition recapitulates the PAH phenotype. In PAH, elevated miRs (notably miR-138) down-regulate MCU directly and also by decreasing MCU's transcriptional regulator cAMP response element-binding protein 1. Nebulized anti-miRs against miR-25 and miR-138 restore MCU expression, reduce cell proliferation, and regress established PAH in the monocrotaline model.
  
  
  CONCLUSIONS
  These results highlight miR-mediated MCUC dysfunction as a unifying mechanism in PAH that can be therapeutically targeted.
authors.affiliation: 1 Department of Medicine, Queen's University, Kingston, Ontario, Canada; and.
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Hong
authors.affiliation: 1 Department of Medicine, Queen's University, Kingston, Ontario, Canada; and.
authors.forename: Kuang-Hueih
authors.initials: KH
authors.lastname: Chen
authors.affiliation: 1 Department of Medicine, Queen's University, Kingston, Ontario, Canada; and.
authors.forename: Asish
authors.initials: A
authors.lastname: DasGupta
authors.affiliation: 2 Pulmonary Hypertension Research Group of the University Cardiology and Pulmonary Institute of the Quebec Research Centre, Laval University, Quebec City, Quebec, Canada.
authors.forename: Francois
authors.initials: F
authors.lastname: Potus
authors.affiliation: 1 Department of Medicine, Queen's University, Kingston, Ontario, Canada; and.
authors.forename: Kimberly
authors.initials: K
authors.lastname: Dunham-Snary
authors.affiliation: 2 Pulmonary Hypertension Research Group of the University Cardiology and Pulmonary Institute of the Quebec Research Centre, Laval University, Quebec City, Quebec, Canada.
authors.forename: Sebastien
authors.initials: S
authors.lastname: Bonnet
authors.affiliation: 1 Department of Medicine, Queen's University, Kingston, Ontario, Canada; and.
authors.forename: Lian
authors.initials: L
authors.lastname: Tian
authors.affiliation: 1 Department of Medicine, Queen's University, Kingston, Ontario, Canada; and.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Fu
authors.affiliation: 2 Pulmonary Hypertension Research Group of the University Cardiology and Pulmonary Institute of the Quebec Research Centre, Laval University, Quebec City, Quebec, Canada.
authors.forename: Sandra
authors.initials: S
authors.lastname: Breuils-Bonnet
authors.affiliation: 2 Pulmonary Hypertension Research Group of the University Cardiology and Pulmonary Institute of the Quebec Research Centre, Laval University, Quebec City, Quebec, Canada.
authors.forename: Steeve
authors.initials: S
authors.lastname: Provencher
authors.affiliation: 1 Department of Medicine, Queen's University, Kingston, Ontario, Canada; and.
authors.forename: Danchen
authors.initials: D
authors.lastname: Wu
authors.affiliation: 1 Department of Medicine, Queen's University, Kingston, Ontario, Canada; and.
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Mewburn
authors.affiliation: 1 Department of Medicine, Queen's University, Kingston, Ontario, Canada; and.
authors.forename: Mark L
authors.initials: ML
authors.lastname: Ormiston
authors.affiliation: 1 Department of Medicine, Queen's University, Kingston, Ontario, Canada; and.
authors.forename: Stephen L
authors.initials: SL
authors.lastname: Archer
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000235:genetics; D002118:Calcium / Q000378:metabolism; D015220:Calcium Channels / Q000235:genetics* / Q000378:metabolism; D002135:Calcium-Binding Proteins / Q000235:genetics*; D016022:Case-Control Studies; D027682:Cation Transport Proteins / Q000235:genetics*; D018929:Cell Culture Techniques / Q000379:methods; D049109:Cell Proliferation / Q000187:drug effects; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism; D003600:Cytosol / Q000378:metabolism; D004195:Disease Models, Animal; D015536:Down-Regulation / Q000235:genetics; D015316:Genetic Therapy / Q000379:methods*; D006019:Glycolysis; D006801:Humans; D006976:Hypertension, Pulmonary / Q000235:genetics* / Q000473:pathology / Q000503:physiopathology / Q000628:therapy; D035683:MicroRNAs / Q000235:genetics*; D033681:Mitochondrial Membrane Transport Proteins / Q000235:genetics*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000473:pathology* / Q000503:physiopathology; D010641:Phenotype; D011651:Pulmonary Artery / Q000187:drug effects / Q000473:pathology*; D011768:Pyruvate Dehydrogenase Complex / Q000378:metabolism; D051381:Rats; D015854:Up-Regulation / Q000235:genetics
chemical_list: D015220:Calcium Channels; D002135:Calcium-Binding Proteins; D027682:Cation Transport Proteins; D017362:Cyclic AMP Response Element-Binding Protein; C116241:MICU1 protein, human; C581260:MIRN138 microRNA, rat; C543351:MIRN25 microRNA, human; C000598929:MIRN25 microRNA, rat; D035683:MicroRNAs; D033681:Mitochondrial Membrane Transport Proteins; D011768:Pyruvate Dehydrogenase Complex; C034703:mitochondrial calcium uniporter; D002118:Calcium
keywords: cAMP response element–binding protein; microRNA-25- and -138-5p; mitochondrial calcium uptake protein 1; pyruvate dehydrogenase