Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1996-9-12
pubmed:abstractText
During human pregnancy, the trophoblast develops from differentiation of cytotrophoblast cells into an endocrine active syncytiotrophoblast. In culture, isolated mononuclear cytotrophoblasts aggregate and then fuse to form a syncytium, reproducing the in vivo process. In this study, we examined the effect of low oxygen tension (approximately 9%, hypoxia) compared to standard conditions (approximately 19% oxygen, normoxia) on these cellular events. Under hypoxia, syncytial formation was less frequently observed, cell staining and electron microscopy revealed that cytotrophoblasts remain aggregated, with a positive proliferative cell nuclear antigen (PCNA) immunostaining. Desmoplakin and E-cadherin, both known to disappear with cytotrophoblast fusion, showed persistent expression in hypoxic cells after 3 days of culture. In contrast, the expression of actin and ezrin, two cytoskeletal proteins, was unchanged. hCG secretion and hPL expression were both decreased in hypoxic cells, reflecting a reduced syncytial formation. Thus, on day 3, the mean values for hCG secretion were 1,100 +/- 155 and 289 +/- 26 mlU/mL in normoxic and hypoxic conditions, respectively. The reduced cell fusion process as well as hCG secretion and hPL expression under hypoxia were reversed by reoxygenation of the cells. We conclude that under hypoxia, the formation of functional syncytiotrophoblast is impaired due to a defect in the cytotrophoblast fusion process. This may explain the observation of a higher number of cytotrophoblast cells and a reduced syncytial layer in placentas of some pathological pregnancies.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0021-9541
pubmed:author
pubmed:issnType
Print
pubmed:volume
168
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
346-53
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:8707870-Actins, pubmed-meshheading:8707870-Cadherins, pubmed-meshheading:8707870-Cell Differentiation, pubmed-meshheading:8707870-Cell Fusion, pubmed-meshheading:8707870-Cell Hypoxia, pubmed-meshheading:8707870-Cell Separation, pubmed-meshheading:8707870-Cells, Cultured, pubmed-meshheading:8707870-Chorionic Gonadotropin, pubmed-meshheading:8707870-Cytoskeletal Proteins, pubmed-meshheading:8707870-Desmoplakins, pubmed-meshheading:8707870-Female, pubmed-meshheading:8707870-Humans, pubmed-meshheading:8707870-Immunoblotting, pubmed-meshheading:8707870-Immunoenzyme Techniques, pubmed-meshheading:8707870-Microscopy, Electron, Scanning, pubmed-meshheading:8707870-Oxygen, pubmed-meshheading:8707870-Placental Lactogen, pubmed-meshheading:8707870-Pregnancy, pubmed-meshheading:8707870-Proliferating Cell Nuclear Antigen, pubmed-meshheading:8707870-Trophoblasts
pubmed:year
1996
pubmed:articleTitle
Hypoxia impairs cell fusion and differentiation process in human cytotrophoblast, in vitro.
pubmed:affiliation
INSERM U427, Faculté des Sciences Pharmaceutiques et Biologiques de Paris, Université René Descartes-Paris V, France.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't