title: Co-ordinated regulation of neurogenin-3 expression in the maternal and fetal pancreas during pregnancy.
abstract: OBJECTIVE
  Several studies have shown increased beta cell mass during pregnancy in both rodents and humans. Proliferation of existing beta cells seems to be the predominant mechanism in rodents, whereas the mechanism in humans is unclear. We hypothesized that neogenesis contributes to the increased beta cell mass in pregnancy and that circulating factors are involved.
  
  
  METHODS
  Pancreatic tissue from mice and rat and serum from pregnant women.
  
  
  METHODS
  Morphometric analysis of pancreas of pregnant and nonpregnant mice was carried out by immunocytochemical staining for the neogenic marker neurogenin-3. Messenger RNA levels of neurogenin-3 and the transcription factor musculoaponeurotic fibrosarcoma oncogene family protein B in fetal rat pancreas cells, cultured with serum from pregnant women, were measured by quantitative polymerase chain reaction.
  
  
  METHODS
  The number of neurogenin-3-positive cells present in pregnant mice was increased compared with nonpregnant mice. Neurogenin-3 and musculoaponeurotic fibrosarcoma oncogene family protein B mRNA was detected in fetal rat pancreas exposed to serum from pregnant women.
  
  
  RESULTS
  In pregnant mice we found a 3.6-fold increase in beta cell volume at day 18 compared with nonpregnant mice and a 3.5-fold increase in neurogenin-3 volume at day 14, mainly located in the acinar compartment where it was eightfold higher than in nonpregnant mice. In fetal rat pancreatic cells exposed to serum from pregnant women we found a marked increase in both neurogenin-3 and musculoaponeurotic fibrosarcoma oncogene family protein B mRNA levels in fibroblast-like cells.
  
  
  CONCLUSIONS
  These results suggest that neogenesis contributes to the increased beta cell mass in pregnancy and that circulating factors are involved in beta cell formation in both the maternal and fetal pancreas during pregnancy.
authors.affiliation: Department of Biomedical Sciences, Cellular and Molecular Medicine Section, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; Centre for Fetal Programming, Danish Research Council for Strategic Research, Copenhagen, Denmark.
authors.forename: Birgitte
authors.initials: B
authors.lastname: Søstrup
authors.forename: Louise W
authors.initials: LW
authors.lastname: Gaarn
authors.forename: Amarnadh
authors.initials: A
authors.lastname: Nalla
authors.forename: Nils
authors.initials: N
authors.lastname: Billestrup
authors.forename: Jens H
authors.initials: JH
authors.lastname: Nielsen
mesh_terms: D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000097:blood*; D005260:Female; D005333:Fetus / Q000378:metabolism*; D006801:Humans; D050417:Insulin-Secreting Cells / Q000378:metabolism*; D051379:Mice; D009419:Nerve Tissue Proteins / Q000097:blood*; D010179:Pancreas / Q000378:metabolism*; D011247:Pregnancy; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D009419:Nerve Tissue Proteins; D012333:RNA, Messenger; C498695:NEUROG3 protein, human; C498696:Neurog3 protein, rat
keywords: Neurogenin-3; beta cells; neogenesis; pancreas; pregnancy