title: Vascular endothelial expression of indoleamine 2,3-dioxygenase 1 forms a positive gradient towards the feto-maternal interface.
abstract: We describe the distribution of indoleamine 2,3-dioxygenase 1 (IDO1) in vascular endothelium of human first-trimester and term placenta. Expression of IDO1 protein on the fetal side of the interface extended from almost exclusively sub-trophoblastic capillaries in first-trimester placenta to a nearly general presence on villous vascular endothelia at term, including also most bigger vessels such as villous arteries and veins of stem villi and vessels of the chorionic plate. Umbilical cord vessels were generally negative for IDO1 protein. In the fetal part of the placenta positivity for IDO1 was restricted to vascular endothelium, which did not co-express HLA-DR. This finding paralleled detectability of IDO1 mRNA in first trimester and term tissue and a high increase in the kynurenine to tryptophan ratio in chorionic villous tissue from first trimester to term placenta. Endothelial cells isolated from the chorionic plate of term placenta expressed IDO1 mRNA in contrast to endothelial cells originating from human umbilical vein, iliac vein or aorta. In first trimester decidua we found endothelium of arteries rather than veins expressing IDO1, which was complementory to expression of HLA-DR. An estimation of IDO activity on the basis of the ratio of kynurenine and tryptophan in blood taken from vessels of the chorionic plate of term placenta indicated far higher values than those found in the peripheral blood of adults. Thus, a gradient of vascular endothelial IDO1 expression is present at both sides of the feto-maternal interface.
authors.affiliation: Institute of Cell Biology, Histology and Embryology, Center for Molecular Medicine, Medical University of Graz, Graz, Austria.
authors.forename: Astrid
authors.initials: A
authors.lastname: Blaschitz
authors.forename: Martin
authors.initials: M
authors.lastname: Gauster
authors.forename: Dietmar
authors.initials: D
authors.lastname: Fuchs
authors.forename: Ingrid
authors.initials: I
authors.lastname: Lang
authors.forename: Petra
authors.initials: P
authors.lastname: Maschke
authors.forename: Daniela
authors.initials: D
authors.lastname: Ulrich
authors.forename: Eva
authors.initials: E
authors.lastname: Karpf
authors.forename: Osamu
authors.initials: O
authors.lastname: Takikawa
authors.forename: Michael G
authors.initials: MG
authors.lastname: Schimek
authors.forename: Gottfried
authors.initials: G
authors.lastname: Dohr
authors.forename: Peter
authors.initials: P
authors.lastname: Sedlmayr
mesh_terms: D002469:Cell Separation; D002823:Chorion / Q000166:cytology / Q000201:enzymology; D003656:Decidua / Q000166:cytology / Q000201:enzymology; D042783:Endothelial Cells / Q000166:cytology / Q000201:enzymology; D004730:Endothelium, Vascular / Q000166:cytology / Q000201:enzymology*; D000939:Epitopes / Q000276:immunology; D005260:Female; D015971:Gene Expression Regulation, Enzymologic; D006684:HLA-DR Antigens; D006801:Humans; D007150:Immunohistochemistry; D050503:Indoleamine-Pyrrole 2,3,-Dioxygenase / Q000235:genetics / Q000378:metabolism*; D008431:Maternal-Fetal Exchange; D016612:Paraffin Embedding; D011247:Pregnancy; D011261:Pregnancy Trimester, First / Q000378:metabolism; D021381:Protein Transport; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D014364:Tryptophan / Q000378:metabolism
chemical_list: D000939:Epitopes; D006684:HLA-DR Antigens; D050503:Indoleamine-Pyrrole 2,3,-Dioxygenase; D012333:RNA, Messenger; D014364:Tryptophan