title: miR-16 and miR-21 expression in the placenta is associated with fetal growth.
abstract: BACKGROUND
  Novel research has suggested that altered miRNA expression in the placenta is associated with adverse pregnancy outcomes and with potentially harmful xenobiotic exposures. We hypothesized that aberrant expression of miRNA in the placenta is associated with fetal growth, a measurable phenotype resulting from a number of intrauterine factors, and one which is significantly predictive of later life outcomes.
  
  
  RESULTS
  We analyzed 107 primary, term, human placentas for expression of 6 miRNA reported to be expressed in the placenta and to regulate cell growth and development pathways: miR-16, miR-21, miR-93, miR-135b, miR-146a, and miR-182. The expression of miR-16 and miR-21 was markedly reduced in infants with the lowest birthweights (p<0.05). Logistic regression models suggested that low expression of miR-16 in the placenta predicts an over 4-fold increased odds of small for gestational age (SGA) status (p = 0.009, 95% CI = 1.42, 12.05). Moreover, having both low miR-16 and low miR-21 expression in the placenta predicts a greater increase in odds for SGA than having just low miR-16 or miR-21 expression (p<0.02), suggesting an additive effect of both of these miRNA.
  
  
  CONCLUSIONS
  Our study is one of the first to investigate placental miRNA expression profiles associated with birthweight and SGA status. Future research on miRNA whose expression is associated with in utero exposures and markers of fetal growth is essential for better understanding the epigenetic mechanisms underlying the developmental origins of health and disease.
authors.affiliation: Department of Pathology and Laboratory Medicine, Brown University, Providence, Rhode Island, United States of America.
authors.forename: Matthew A
authors.initials: MA
authors.lastname: Maccani
authors.forename: James F
authors.initials: JF
authors.lastname: Padbury
authors.forename: Carmen J
authors.initials: CJ
authors.lastname: Marsit
mesh_terms: D015153:Blotting, Western; D002478:Cells, Cultured; D005260:Female; D047109:Fetal Development / Q000235:genetics*; D006801:Humans; D035683:MicroRNAs / Q000235:genetics*; D010920:Placenta / Q000378:metabolism*; D011247:Pregnancy; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: C505362:MIRN16 microRNA, human; C524940:MIRN21 microRNA, human; D035683:MicroRNAs