Linked Life Data

1502136

Source:http://linkedlifedata.com/resource/pubmed/id/1502136

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1992-9-17
pubmed:abstractText
In most cell types, transferrin receptor expression is correlated with the proliferation rate, being increased by growth stimulation, or decreased by induction of terminal differentiation. In the human placenta the multinucleated syncytiotrophoblast, in direct contact with maternal blood, is derived by differentiation from mononucleated cytotrophoblast. In this study we examined changes in transferrin receptor expression during in vitro differentiation of trophoblast. Cells cultured in Ham's/Waymouth's medium (HWM) remained primarily mononuclear throughout the study, whereas incubation in keratinocyte growth medium (KGM) led to formation of multinucleate masses within 2-3 days of culture. Cell surface binding of 125I-labelled transferrin increased fivefold between days 1-5 of culture in both media and surface receptors were saturated at 7-14 micrograms/ml (90-200 fM). At saturation, the amount of transferrin bound to syncytiotrophoblast was 37 per cent lower than in cytotrophoblast. Scatchard analysis revealed a reduction in the number of surface transferrin receptors in syncytiotrophoblast compared to cytotrophoblast. A corresponding 29 per cent reduction in the binding of transferrin to intracellular sites was observed in syncytiotrophoblast. Distribution of receptors between surface and intracellular sites was therefore similar in both cytotrophoblast and syncytiotrophoblast. The affinity of transferrin for transferrin receptors was 3.7-fold higher in syncytiotrophoblast when compared to cytotrophoblast. Observed differences between the two cell types were not due to the presence of growth factors or higher iron levels in KGM. Expression of a high number of surface transferrin receptors in syncytiotrophoblast (1.5 x 10(12)/mg protein), along with a high affinity of these receptors for iron-saturated transferrin, could help explain the efficient transport of large amounts of iron from mother to fetus.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0143-4004
pubmed:author
pubmed:issnType
Print
pubmed:volume
13
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
43-53
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed:articleTitle
Expression of transferrin receptors during differentiation of human placental trophoblast cells in vitro.
pubmed:affiliation
Department of Cell Biology and Human Anatomy, School of Medicine, University of California, Davis 95616-8643.
pubmed:publicationType
Journal Article, In Vitro, Research Support, U.S. Gov't, P.H.S.