title: Regulation of progesterone receptor A and B expression in human preterm, term, and postterm placental villi.
abstract: OBJECTIVE
  The progesterone receptor (PR)-A/B ratio in the myometrium is reported to be closely related to labor onset. This might represent a potential target for therapeutic interventions for postterm and preterm deliveries, though the mechanisms currently remain unknown. The aim of this study was to investigate the regulation mechanism of PR-A and B expression in human preterm, term, and postterm placental villi.
  
  
  METHODS
  Experimental study.
  
  
  METHODS
  People's Hospital of Jiangsu Province, China.
  
  
  METHODS
  Singleton women of preterm (PRNIL, not in labor, n = 10), term (TNIL, not in labor, n = 10; TIL, in labor, n = 10), and postterm (PONIL, not in labor, n = 10) cesarean deliveries.
  
  
  METHODS
  The PR-A/PR-B mRNA and protein ratios were analyzed using real-time reverse transcription-polymerase chain reaction and western blots in villi from preterm, term, postterm groups. PONIL and PRNIL villi were incubated with prostaglandin F(2alpha) (PG) and indomethacin for 72 hours, respectively, and the PR-A/PR-B mRNA and protein ratios and p38 signaling pathway were explored.
  
  
  RESULTS
  The PR-A/PR-B ratio was highest in TIL, followed by PRNIL, PONIL and TNIL. Indomethacin significantly up-regulated PR-B expression, thereby decreasing the PR-A/PR-B ratio (p < 0.05). Meanwhile, PG reduced the expression of PR-B and increased PR-A, leading to a significant increase in the PR-A/PR-B ratio (p < 0.05). We also determined that the PR-A/PR-B ratio was mediated through the activation of p38 mitogen-activated protein kinase.
  
  
  CONCLUSIONS
  These results demonstrate that the PR-A/PR-B ratio plays a key role in the mechanisms regulating preterm, term, and postterm deliveries.
authors.affiliation: Department of Obstetrics and Gynaecology, Nanjing Medical University, Nanjing, China.
authors.forename: Jiang
authors.initials: J
authors.lastname: Ziyan
authors.forename: Ren
authors.initials: R
authors.lastname: Huaibin
authors.forename: Ma
authors.initials: M
authors.lastname: Xiaotian
authors.forename: She
authors.initials: S
authors.lastname: Guangtong
authors.forename: Chen
authors.initials: C
authors.lastname: Xiaoqing
authors.forename: Dong
authors.initials: D
authors.lastname: Zijiang
authors.forename: Jiang
authors.initials: J
authors.lastname: Ziyue
authors.forename: De
authors.initials: D
authors.lastname: We
authors.forename: Sun
authors.initials: S
authors.lastname: Lizhou
mesh_terms: D000328:Adult; D015153:Blotting, Western; D002681:China; D002824:Chorionic Villi / Q000378:metabolism*; D015193:Chorionic Villi Sampling; D015331:Cohort Studies; D005260:Female; D005865:Gestational Age; D006801:Humans; D007213:Indomethacin / Q000494:pharmacology; D007231:Infant, Newborn; D007743:Labor, Obstetric; D011247:Pregnancy; D011273:Pregnancy, Prolonged; D047928:Premature Birth; D011336:Probability; D012333:RNA, Messenger / Q000032:analysis; D011980:Receptors, Progesterone / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D047929:Term Birth; D015149:Tocolytic Agents / Q000494:pharmacology; D015854:Up-Regulation / Q000187:drug effects
chemical_list: D012333:RNA, Messenger; D011980:Receptors, Progesterone; D015149:Tocolytic Agents; C101118:progesterone receptor A; C097314:progesterone receptor B; D007213:Indomethacin