title: MEF2C-MYOCD and Leiomodin1 Suppression by miRNA-214 Promotes Smooth Muscle Cell Phenotype Switching in Pulmonary Arterial Hypertension.
abstract: Vascular hyperproliferative disorders are characterized by excessive smooth muscle cell (SMC) proliferation leading to vessel remodeling and occlusion. In pulmonary arterial hypertension (PAH), SMC phenotype switching from a terminally differentiated contractile to synthetic state is gaining traction as our understanding of the disease progression improves. While maintenance of SMC contractile phenotype is reportedly orchestrated by a MEF2C-myocardin (MYOCD) interplay, little is known regarding molecular control at this nexus. Moreover, the burgeoning interest in microRNAs (miRs) provides the basis for exploring their modulation of MEF2C-MYOCD signaling, and in turn, a pro-proliferative, synthetic SMC phenotype. We hypothesized that suppression of SMC contractile phenotype in pulmonary hypertension is mediated by miR-214 via repression of the MEF2C-MYOCD-leiomodin1 (LMOD1) signaling axis.
  
  
  
  In SMCs isolated from a PAH patient cohort and commercially obtained hPASMCs exposed to hypoxia, miR-214 expression was monitored by qRT-PCR. miR-214 was upregulated in PAH- vs. control subject hPASMCs as well as in commercially obtained hPASMCs exposed to hypoxia. These increases in miR-214 were paralleled by MEF2C, MYOCD and SMC contractile protein downregulation. Of these, LMOD1 and MEF2C were directly targeted by the miR. Mir-214 overexpression mimicked the PAH profile, downregulating MEF2C and LMOD1. AntagomiR-214 abrogated hypoxia-induced suppression of the contractile phenotype and its attendant proliferation. Anti-miR-214 also restored PAH-PASMCs to a contractile phenotype seen during vascular homeostasis.
  
  
  
  Our findings illustrate a key role for miR-214 in modulation of MEF2C-MYOCD-LMOD1 signaling and suggest that an antagonist of miR-214 could mitigate SMC phenotype changes and proliferation in vascular hyperproliferative disorders including PAH.
authors.affiliation: Department of Pharmacology and Chemical Biology University of Pittsburgh, Pittsburgh, Pennsylvania, 15261, United States of America.|Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, Pennsylvania, 15261, United States of America.
authors.forename: Sanghamitra
authors.initials: S
authors.lastname: Sahoo
authors.affiliation: Department of Pharmacology and Chemical Biology University of Pittsburgh, Pittsburgh, Pennsylvania, 15261, United States of America.|Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, Pennsylvania, 15261, United States of America.
authors.forename: Daniel N
authors.initials: DN
authors.lastname: Meijles
authors.affiliation: Department of Pharmacology and Chemical Biology University of Pittsburgh, Pittsburgh, Pennsylvania, 15261, United States of America.|Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, Pennsylvania, 15261, United States of America.
authors.forename: Imad
authors.initials: I
authors.lastname: Al Ghouleh
authors.affiliation: Department of Pharmacology and Chemical Biology University of Pittsburgh, Pittsburgh, Pennsylvania, 15261, United States of America.
authors.forename: Manuj
authors.initials: M
authors.lastname: Tandon
authors.affiliation: Department of Pharmacology and Chemical Biology University of Pittsburgh, Pittsburgh, Pennsylvania, 15261, United States of America.|Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, Pennsylvania, 15261, United States of America.
authors.forename: Eugenia
authors.initials: E
authors.lastname: Cifuentes-Pagano
authors.affiliation: Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, Pennsylvania, 15261, United States of America.|Division of Pulmonary, Allergy and Critical Care Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, 15261, United States of America.
authors.forename: John
authors.initials: J
authors.lastname: Sembrat
authors.affiliation: Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, Pennsylvania, 15261, United States of America.|Division of Pulmonary, Allergy and Critical Care Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, 15261, United States of America.
authors.forename: Mauricio
authors.initials: M
authors.lastname: Rojas
authors.affiliation: Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, Pennsylvania, 15261, United States of America.|Division of Pulmonary, Allergy and Critical Care Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, 15261, United States of America.
authors.forename: Elena
authors.initials: E
authors.lastname: Goncharova
authors.affiliation: Department of Pharmacology and Chemical Biology University of Pittsburgh, Pittsburgh, Pennsylvania, 15261, United States of America.|Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, Pennsylvania, 15261, United States of America.
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: Pagano
mesh_terms: D000070416:Antagomirs / Q000378:metabolism; D001324:Autoantigens / Q000378:metabolism*; D002454:Cell Differentiation / Q000502:physiology; D002460:Cell Line; D049109:Cell Proliferation / Q000502:physiology; D003598:Cytoskeletal Proteins / Q000378:metabolism*; D015536:Down-Regulation / Q000502:physiology; D065627:Familial Primary Pulmonary Hypertension / Q000378:metabolism; D057809:HEK293 Cells; D006801:Humans; D006976:Hypertension, Pulmonary / Q000378:metabolism*; D064326:MEF2 Transcription Factors / Q000378:metabolism; D035683:MicroRNAs / Q000378:metabolism*; D009119:Muscle Contraction / Q000502:physiology; D009131:Muscle, Smooth, Vascular / Q000378:metabolism; D032389:Myocytes, Smooth Muscle / Q000378:metabolism*; D009687:Nuclear Proteins / Q000378:metabolism*; D010641:Phenotype; D011651:Pulmonary Artery / Q000378:metabolism*; D015534:Trans-Activators / Q000378:metabolism*; D015854:Up-Regulation / Q000502:physiology; D000099251:Myocardin
chemical_list: D000070416:Antagomirs; D001324:Autoantigens; D003598:Cytoskeletal Proteins; D064326:MEF2 Transcription Factors; D035683:MicroRNAs; D009687:Nuclear Proteins; D015534:Trans-Activators; D000099251:Myocardin; C103926:LMOD1 protein, human; C578040:MEF2C protein, human