title: miR-424/322 regulates vascular smooth muscle cell phenotype and neointimal formation in the rat.
abstract: OBJECTIVE
  Our aim was to identify new microRNAs (miRNAs) implicated in pathological vascular smooth muscle cells (VSMCs) proliferation and characterize their mechanism of action.
  
  
  RESULTS
  MicroRNAs microarray and qRT-PCR results lead us to focus on miR-424 or its rat ortholog miR-322 (miR-424/322). In vitro mir-424/322 level was decreased shortly after the induction of proliferation and increased in a time-dependent manner later on. In vivo its expression increased in the rat carotid artery from Day 4 up to Day 30 after injury. miR-424/322 overexpression in vitro inhibited proliferation and migration without affecting apoptosis and prevented VSMC dedifferentiation. Furthermore, miR-424/322 overexpression resulted in decreased expression of its predicted targets: cyclin D1 and Ca(2+)-regulating proteins calumenin and stromal-interacting molecule 1 (STIM1). Using reporter luciferase assays, we confirmed that cyclin D1 and calumenin mRNAs were direct targets of miR-322, whereas miR-322 effect on STIM1 was indirect. Nevertheless, consistent with the decreased STIM1 level, the store-operated Ca(2+) entry was reduced. We hypothesized that miR-424/322 could be a negative regulator of proliferation overridden in pathological situations. Thus, we overexpressed miR-424/322 in injured rat carotid arteries using an adenovirus, and demonstrated a protective effect against restenosis.
  
  
  CONCLUSIONS
  Our results demonstrate that miR-424/322 is up-regulated after vascular injury. This is likely an adaptive response to counteract proliferation, although this mechanism is overwhelmed in pathological situations such as injury-induced restenosis.
authors: INSERM UMRS 956, Faculté de Médecine Pierre et Marie Curie, 91 boulevard de l'Hôpital, 75634, Paris Cedex 13, France.
authors: Elise
authors: E
authors: Merlet
authors: Fabrice
authors: F
authors: Atassi
authors: Rajender K
authors: RK
authors: Motiani
authors: Nathalie
authors: N
authors: Mougenot
authors: Adeline
authors: A
authors: Jacquet
authors: Sophie
authors: S
authors: Nadaud
authors: Thierry
authors: T
authors: Capiod
authors: Mohamed
authors: M
authors: Trebak
authors: Anne-Marie
authors: AM
authors: Lompré
authors: Alexandre
authors: A
authors: Marchand
mesh_terms: D000818:Animals; D017209:Apoptosis; D002118:Calcium / Q000378:metabolism; D002135:Calcium-Binding Proteins / Q000378:metabolism; D020212:Carotid Artery Injuries / Q000235:genetics / Q000378:metabolism* / Q000473:pathology / Q000517:prevention & control; D002342:Carotid Artery, External / Q000378:metabolism / Q000473:pathology; D054337:Cell Dedifferentiation; D002465:Cell Movement; D049109:Cell Proliferation; D002478:Cells, Cultured; D019938:Cyclin D1 / Q000378:metabolism; D004195:Disease Models, Animal; D006801:Humans; D008297:Male; D008562:Membrane Glycoproteins / Q000378:metabolism; D035683:MicroRNAs / Q000378:metabolism*; D009131:Muscle, Smooth, Vascular / Q000378:metabolism* / Q000473:pathology; D032389:Myocytes, Smooth Muscle / Q000378:metabolism* / Q000473:pathology; D058426:Neointima; D010641:Phenotype; D051381:Rats; D017208:Rats, Wistar; D015398:Signal Transduction; D000071737:Stromal Interaction Molecule 1; D013997:Time Factors; D014162:Transfection; D015854:Up-Regulation
chemical_list: D002135:Calcium-Binding Proteins; C532544:Calu protein, rat; C530106:Ccnd1 protein, rat; C585349:MIRN322 microRNA, rat; C554214:MIRN424 microrna, human; D008562:Membrane Glycoproteins; D035683:MicroRNAs; C518857:Stim1 protein, rat; D000071737:Stromal Interaction Molecule 1; D019938:Cyclin D1; D002118:Calcium
keywords: Calcium; MicroRNA; Proliferation; Restenosis; Vascular smooth muscle cells