title: Measurement of mRNA transcripts of very high placental expression in maternal blood as biomarkers of preeclampsia.
abstract: BACKGROUND
  mRNA of placental origin in maternal blood shows potential as a clinical biomarker of obstetric diseases such as preeclampsia (PE). We hypothesized that mRNA transcripts very highly expressed in the placenta relative to other tissues will be differentially expressed in PE and be useful as mRNA biomarkers in maternal blood.
  
  
  OBJECTIVE
  Our objective was to identify a panel of genes highly expressed in the placenta and compare their expression in placenta and maternal whole blood from PE vs. control pregnancies.
  
  
  METHODS
  Placental tissue and maternal whole blood specimens were obtained from normotensive controls (n = 15) and pregnancies complicated by severe preterm PE (n = 21).
  
  
  METHODS
  mRNA expression was evaluated by quantitative real-time RT-PCR.
  
  
  RESULTS
  We identified 20 genes exhibiting highest to fourth highest expression in the placenta relative to all other tissues. All genes were detectable in placenta. Nine of the 20 genes were detectable in maternal whole blood. Four of the nine genes detectable in blood (i.e. PLAC3, PLAC4, CRH, and ERVWE1) were significantly increased in both maternal blood and placenta from PE pregnancies. The remaining five genes detectable in maternal blood were unchanged in both blood and placenta from PE pregnancies. Thus, there was complete correlation of gene expression between maternal blood and placenta.
  
  
  CONCLUSIONS
  Circulating mRNA coding genes of high placental expression show strong correlation with transcript levels in preeclamptic placenta. Such transcripts may be promising candidates to screen as mRNA biomarkers of PE in maternal whole blood.
authors.affiliation: The Ritchie Centre, Monash Institute of Medical Research, Monash University, Clayton, Victoria 3168, Australia.
authors.forename: Premila
authors.initials: P
authors.lastname: Paiva
authors.forename: Clare
authors.initials: C
authors.lastname: Whitehead
authors.forename: Burcu
authors.initials: B
authors.lastname: Saglam
authors.forename: Kirsten
authors.initials: K
authors.lastname: Palmer
authors.forename: Stephen
authors.initials: S
authors.lastname: Tong
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000032:analysis / Q000378:metabolism; D005260:Female; D015870:Gene Expression; D006801:Humans; D010920:Placenta / Q000378:metabolism*; D011225:Pre-Eclampsia / Q000175:diagnosis* / Q000235:genetics / Q000378:metabolism; D011247:Pregnancy; D012333:RNA, Messenger / Q000032:analysis* / Q000235:genetics / Q000378:metabolism
chemical_list: D015415:Biomarkers; D012333:RNA, Messenger