TY - JOUR
T1 - Dynamic Changes in Amniotic Tight Junctions during Pregnancy
AU - Kobayashi, K.
AU - Inai, T.
AU - Shibata, Y.
AU - Yasui, M.
N1 - Funding Information:
This work was supported by a Grant-in-Aid for Young Scientists (20790177) from the Japan Society of Promotion of Science, a Grant-in-Aid for Specially Promoted Research from the Ministry of Education, Culture, Sports, Science and Technology (MEXT) of Japan, and in part by the Jinsenkai Medical Foundation.
PY - 2009/10
Y1 - 2009/10
N2 - 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.
AB - 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.
KW - Amnion
KW - Amniotic fluid
KW - Apoptosis
KW - Claudins
KW - Tight junctions
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U2 - 10.1016/j.placenta.2009.07.009
DO - 10.1016/j.placenta.2009.07.009
M3 - Article
C2 - 19692119
AN - SCOPUS:70149106333
SN - 0143-4004
VL - 30
SP - 840
EP - 847
JO - Placenta
JF - Placenta
IS - 10
ER -