Expression and distribution of tight junction proteins in human amnion during late pregnancy.
Amnion is the innermost layer of the fetal membrane and has been suggested to regulate the volume of amniotic fluid via the amniotic epithelium. The transepithelial pathway is generally restricted by tight junctions (TJs). Thus far, human amniotic TJs have not been identified. In this study, we determined whether the human amniotic epithelium contains TJs. Reverse transcription polymerase chain reaction (RT-PCR) and western blotting analyses showed that the human amniotic epithelium has TJ components, such as occludin, ZO-1, and at least 2 types of claudins, i.e., claudin-4 and claudin-7. The TJ components were found to localize in the lateral membranes and cytoplasm at 35 weeks of gestation; these components disappeared from the lateral membrane at 37 weeks of gestation. Organ culturing of the amnion at 37 weeks gestation induced the relocalization of the TJ proteins from the cytoplasm to the lateral membranes. Furthermore, in cultured amniotic epithelial cells, dexamethasone induced the downregulation of the protein expression of TJs. These findings suggest that the human amniotic epithelium has TJs that disrupt during late pregnancy. The disruption may be induced by several factors such as glucocorticoids present in the amniotic fluid during late pregnancy.
Kobayashi
K
K
Department of Pharmacology, School of Medicine, Keio University, Tokyo, Japan.
Kadohira
I
I
Tanaka
M
M
Yoshimura
Y
Y
Ikeda
K
K
Yasui
M
M
D000650:Amnion / Q000166:cytology* / Q000378:metabolism*; D002478:Cells, Cultured; D062506:Claudin-4; D057167:Claudins; D003907:Dexamethasone / Q000037:antagonists & inhibitors / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004847:Epithelial Cells / Q000166:cytology / Q000378:metabolism; D005260:Female; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects; D005938:Glucocorticoids / Q000037:antagonists & inhibitors / Q000494:pharmacology; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D009928:Organ Specificity; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism; D011247:Pregnancy; D011257:Pregnancy Proteins / Q000235:genetics / Q000378:metabolism*; D011263:Pregnancy Trimester, Third / Q000378:metabolism*; D021381:Protein Transport / Q000187:drug effects; D017154:Stromal Cells / Q000166:cytology / Q000378:metabolism; D019108:Tight Junctions / Q000235:genetics / Q000378:metabolism*; D013997:Time Factors; D062826:Zonula Occludens-1 Protein
C568157:CLDN4 protein, human; C473255:CLDN7 protein, human; D062506:Claudin-4; D057167:Claudins; D005938:Glucocorticoids; D008565:Membrane Proteins; D010750:Phosphoproteins; D011257:Pregnancy Proteins; C569042:TJP1 protein, human; D062826:Zonula Occludens-1 Protein; D003907:Dexamethasone