Dynamic Changes in Amniotic Tight Junctions during Pregnancy

K. Kobayashi, T. Inai, Y. Shibata, M. Yasui

Research output: Contribution to journalArticle

10 Citations (Scopus)

Abstract

The amniotic membrane encloses and retains amniotic fluid during pregnancy. In general, fluid flux is regulated by epithelial tissues, which have tight junctions (TJs). However, TJs have not yet been identified in the amniotic epithelium. In this study, we have determined whether the mouse amniotic epithelium contains TJs. Freeze-fracture electron microscopy revealed the presence of strand-like TJs in the amniotic epithelium. Amniotic TJs were composed of occludin; zona occludens (ZO)-1; and claudins 1, 3, 4, and 7. These claudins underwent developmental changes during pregnancy. The localization patterns of the claudins and their detergent solubility drastically changed between embryonic day (E) 16 and E17; the volume of the amniotic fluid also decreased sharply. Furthermore, in vitro assessment of amniotic membrane permeability showed that the amniotic membrane was more permeable on E17 than on E16. On E17, TJ components were sparsely distributed in parts of the amniotic epithelium. The results of Annexin V-fluorescein staining and Terminal dUTP nick-end labeling (TUNEL) assay revealed ongoing apoptosis in all the cells in such regions. The above findings suggest that TJs in the amniotic epithelium maintain amniotic fluid volume during pregnancy, while apoptosis of amniotic epithelial cells between E16 and E17 causes disruption of the TJs.

Original languageEnglish
Pages (from-to)840-847
Number of pages8
JournalPlacenta
Volume30
Issue number10
DOIs
Publication statusPublished - 2009 Oct 1

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Keywords

  • Amnion
  • Amniotic fluid
  • Apoptosis
  • Claudins
  • Tight junctions

ASJC Scopus subject areas

  • Reproductive Medicine
  • Obstetrics and Gynaecology
  • Developmental Biology

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