Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
11-12
pubmed:dateCreated
2007-10-22
pubmed:abstractText
The human first trimester placenta experiences a low oxygen environment. The hypoxia inducible factors (HIFs) mediate the response to low oxygen, inducing genes such as insulin-like growth factor (IGF)-II. Interestingly, IGF-II has been shown to promote placental growth and function. Currently, the interaction between oxygen, IGF-II and HIFs in the regulation of trophoblast behaviour are unclear. Murine implantation sites from days 5.5-10.5 were collected for immunohistochemical analyses. Use of the hypoxia marker pimonidazole indicated that the early mouse implantation site is exposed to low oxygen levels similar to those seen in the early human placenta. HIF-1alpha protein immunostaining was also observed in the implantation site. Culturing murine ectoplacental cones in decreasing oxygen concentrations (20%, 5% and 1% O(2)), either with or without the addition of IGF-II, induced complex responses by trophoblasts in terms of their migration and differentiation. Following 3 days exposure to low oxygen there was reduced EPC outgrowth, reduced Igf2 and increased Tpbp mRNA levels, suggesting commitment to the spongiotrophoblast lineage. In addition, Hif-1alpha mRNA levels were decreased, whilst Hif-2alpha mRNA was unchanged. This decrease in Hif-1alpha may be due to the observed increase in antisense (as) Hif-1alpha mRNA levels in 1% cultures. Furthermore, expression of Hif-2alpha and the HIF target genes: asHif-1alpha, Vegf and Slc2a1 were reduced under low oxygen with the addition of IGF-II. In conclusion, Hif-1alpha and Hif-2alpha are differentially regulated by oxygen and IGF-II in cultured trophoblast cells and asHif-1alpha may mediate the response to prolonged hypoxia in murine trophoblasts.
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
28
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1147-57
pubmed:meshHeading
pubmed-meshheading:17658597-Animals, pubmed-meshheading:17658597-Biological Markers, pubmed-meshheading:17658597-Cell Differentiation, pubmed-meshheading:17658597-Cell Hypoxia, pubmed-meshheading:17658597-Cells, Cultured, pubmed-meshheading:17658597-Decidua, pubmed-meshheading:17658597-Female, pubmed-meshheading:17658597-Hypoxia-Inducible Factor 1, alpha Subunit, pubmed-meshheading:17658597-Immunohistochemistry, pubmed-meshheading:17658597-Insulin-Like Growth Factor II, pubmed-meshheading:17658597-Male, pubmed-meshheading:17658597-Mice, pubmed-meshheading:17658597-Mice, Inbred C57BL, pubmed-meshheading:17658597-Oxygen, pubmed-meshheading:17658597-Polymerase Chain Reaction, pubmed-meshheading:17658597-RNA, Messenger, pubmed-meshheading:17658597-Receptor, IGF Type 2, pubmed-meshheading:17658597-Trophoblasts
pubmed:articleTitle
Complex interactions between hypoxia inducible factors, insulin-like growth factor-II and oxygen in early murine trophoblasts.
pubmed:affiliation
Research Centre for Reproductive Health, Discipline of Obstetrics and Gynaecology, School of Paediatrics and Reproductive Health, University of Adelaide, Adelaide, SA 5005, Australia.
pubmed:publicationType
Journal Article, Research Support, N.I.H., Extramural