Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:dateCreated
2002-5-17
pubmed:abstractText
The placenta has been the subject of extensive basic research efforts in two distinct fields. The developmental biology of placenta has been studied because it is the first organ to develop during embryogenesis and because a number of different gene mutations in mice result in embryonic lethality due to placental defects. The trophoblast cell lineage is relatively simple such that only two major, terminally differentiated cell types appear: an "invasive trophoblast" cell subtype such as extravillous cytotrophoblast cells in humans and trophoblast giant cells in mice, and a "transport trophoblast" cell subtype that is a syncytium (syncytiotrophoblast) in humans and mice. These two cell types also have been the focus of endocrinologists because they are the source of major placental hormones. Understanding the transcriptional regulation of placental hormone genes has given insights into the control of specificity of gene expression. Because most placental hormones are produced by very specific trophoblast cell subtypes, the transcriptional details promise to give insights into cell-subtype specification. The fields of developmental biology and molecular endocrinology appear to be meeting on this common ground with the recent discovery of key transcription factors. Specifically, the basic helix-loop-helix (bHLH) transcription factor Hand1 is essential for differentiation of trophoblast giant cells in mice and also regulates the promoter for the giant cell-specific hormone, placental lactogen I gene (Pl1). In contrast, formation of syncytiotrophoblast cells in mice is controlled by a distinct genetic pathway that is governed by the Gcm1 transcription factor, a homologue of the Drosophila glial cells missing gene. Human GCM I has been shown to regulate the activity of the placental-specific enhancer of the aromatase gene (CYP19), which is specifically expressed in syncytiotrophoblast. Together, these findings imply that some key transcription factors have the dual functions of controlling both critical cell fate decisions in the trophoblast cell lineage and later the transcription of cell subtype-specific genes unrelated to development.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0079-9963
pubmed:author
pubmed:issnType
Print
pubmed:volume
57
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
221-34
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
Transcription factors underlying the development and endocrine functions of the placenta.
pubmed:affiliation
Department of Biochemistry & Molecular Biology, University of Calgary Faculty of Medicine, Alberta, Canada. jcrooss@ucalgary.ca
pubmed:publicationType
Journal Article, Review, Research Support, Non-U.S. Gov't