title: Characterization of progesterone receptor isoform expression in fetal membranes.
abstract: OBJECTIVE
  To quantify expression of progesterone receptor (PR) messenger RNA (mRNA) isoforms in fetal membranes, and to determine whether these levels change in culture.
  
  
  METHODS
  Placentas from women undergoing term cesarean delivery before labor were collected. Layers of amnion, chorion, and decidua were separated manually, enzymatically digested, and separated further with the use of a density gradient. RNA was extracted immediately and after culture for 48 hours, then analyzed by quantitative reverse transcription polymerase chain reaction for PR-A, PR-B, and beta-2 microglobulin mRNA expression. Separation of cell types was confirmed by immunohistochemistry.
  
  
  RESULTS
  PR isoform expression was identified in fetal membranes, with levels highest in decidua and below the limits of detection in amnion. The ratio of PR-A/PR-B mRNA was not significantly different between cell layers. PR mRNA isoform levels did not differ significantly in fresh versus cultured cells.
  
  
  CONCLUSIONS
  Quantitative reverse transcription polymerase chain reaction was used to quantitate expression of PR mRNA isoforms in cells of fetal membranes and to validate systems for further study of PR with respect to inflammation, infection, and preterm delivery.
authors.affiliation: Department of Obstetrics and Gynecology, Division of Maternal-Fetal Medicine, Duke University Medical Center, Durham, NC, USA.
authors.forename: Alyssa A
authors.initials: AA
authors.lastname: Mills
authors.forename: Bryan
authors.initials: B
authors.lastname: Yonish
authors.forename: Liping
authors.initials: L
authors.lastname: Feng
authors.forename: David W
authors.initials: DW
authors.lastname: Schomberg
authors.forename: R Phillips
authors.initials: RP
authors.lastname: Heine
authors.forename: Amy P
authors.initials: AP
authors.lastname: Murtha
mesh_terms: D005321:Extraembryonic Membranes / Q000737:chemistry*; D005260:Female; D006801:Humans; D007743:Labor, Obstetric / Q000502:physiology; D011247:Pregnancy; D020033:Protein Isoforms; D012333:RNA, Messenger / Q000032:analysis; D011980:Receptors, Progesterone / Q000032:analysis* / Q000235:genetics / Q000502:physiology; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D020033:Protein Isoforms; D012333:RNA, Messenger; D011980:Receptors, Progesterone