title: Expression of placental leptin and leptin receptor transcripts in early pregnancy and at term.
abstract: OBJECTIVE
  To demonstrate the expression of messenger RNA (mRNA) transcripts for placental leptin and leptin receptor in early gestation and at term, to quantitate transcriptional changes relative to stage of gestation, to localize transcripts within specific placental cell types, and to determine if transcripts also are expressed in cultured cells.
  
  
  METHODS
  Expression of leptin and leptin receptor was assessed by reverse transcriptase-polymerase chain reaction, and leptin quantitated against a leptin mRNA competitor (MIMIC), in human placental villous tissue collected at term cesarean deliveries and earlier during gestation (7-14 weeks) upon elective terminations. In situ hybridization was used to identify cell types exhibiting transcripts for genes of interest. Additionally, tissue was dispersed enzymatically, cytotrophoblast cells progressed to syncytiotrophoblastic maturity in culture, and transcripts were assessed.
  
  
  RESULTS
  Placental leptin and leptin receptor transcripts were identified in early (n = 6) and late (n = 5) gestation. Although no changes (P > .05) were apparent for receptor, leptin mRNA declined (P < .005) from (mean+/-standard error) 1.815+/-.491 attomoles/microg total RNA early in gestation to .013+/-.003 attomoles/microg total RNA at term. Leptin and leptin receptor transcripts were localized in trophoblast by in situ hybridization and were expressed in culture.
  
  
  CONCLUSIONS
  Results suggest an ontogenetic decline in leptin mRNA with advancing gestation. Localization of leptin and leptin receptor transcripts in syncytiotrophoblasts, cells also responsible for the production of hormones vital to pregnancy maintenance, suggest a potential for autocrine or paracrine interactions within this tissue. Finally, transcript expression in cultured cells suggests the suitability of in vitro paradigms for future studies of leptin in pregnancy.
authors.affiliation: Department of Obstetrics and Gynecology, Tulane University School of Medicine, New Orleans, Louisiana 70112-2699, USA. henson@mailhost.tcs.tulane.edu
authors.forename: M C
authors.initials: MC
authors.lastname: Henson
authors.forename: K F
authors.initials: KF
authors.lastname: Swan
authors.forename: J S
authors.initials: JS
authors.lastname: O'Neil
mesh_terms: D000273:Adipose Tissue / Q000378:metabolism*; D002352:Carrier Proteins / Q000235:genetics*; D005260:Female; D015870:Gene Expression; D006801:Humans; D020738:Leptin; D010920:Placenta / Q000378:metabolism*; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D011263:Pregnancy Trimester, Third; D011506:Proteins / Q000235:genetics*; D012333:RNA, Messenger / Q000096:biosynthesis; D011956:Receptors, Cell Surface; D018121:Receptors, Cytokine / Q000235:genetics*; D054411:Receptors, Leptin
chemical_list: D002352:Carrier Proteins; C515448:LEPR protein, human; D020738:Leptin; D011506:Proteins; D012333:RNA, Messenger; D011956:Receptors, Cell Surface; D018121:Receptors, Cytokine; D054411:Receptors, Leptin