X-linked inhibitor of apoptosis protein expression and the regulation of apoptosis during human placental development.
In this study, we have examined the expression and potential role of X-linked inhibitor of apoptosis protein (XIAP), Fas, and Fas ligand (FasL) in the regulation of apoptosis throughout placental development. Protein expression was determined by Western blot analysis and immunohistochemistry, whereas apoptotic cell death was assessed by DNA fragmentation analysis and TUNEL. The XIAP was present in trophoblast throughout placental development, but its content significantly decreased during late pregnancy, when apoptosis was maximal. The FasL content was low during early placental development but increased coincidentally to the decrease in XIAP during the third trimester. Our data also suggest that placental apoptosis is the culmination of the relative expression of these cell-death and -survival proteins, a phenomenon that is cell type-specific and dependent on cytodifferentiation and the stage of placental development. Moreover, the induction of syncytiotrophoblast apoptosis may involve the concomitant up-regulation of FasL for Fas activation and the removal of downstream inhibition of the apoptotic cascade by XIAP.
Division Maternal-Fetal Medicine, Reproductive Biology Unit, Department of Obstetrics and Gynecology, University of Ottawa, and the Ottawa Hospital Loeb Research Institute, Ottawa Hospital, Ottawa, Ontario, Canada K1H 8L6. agruslin@ottawahospital.on.ca
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Tsang
D017209:Apoptosis / Q000502:physiology*; D015153:Blotting, Western; D053938:DNA Fragmentation; D053222:Fas Ligand Protein; D005260:Female; D005865:Gestational Age; D006801:Humans; D007150:Immunohistochemistry; D020287:In Situ Nick-End Labeling; D008562:Membrane Glycoproteins / Q000032:analysis; D010920:Placenta / Q000737:chemistry* / Q000502:physiology*; D011247:Pregnancy; D011506:Proteins / Q000032:analysis*; D015398:Signal Transduction; D017154:Stromal Cells / Q000737:chemistry; D014327:Trophoblasts / Q000737:chemistry; D051636:X-Linked Inhibitor of Apoptosis Protein; D019014:fas Receptor / Q000032:analysis
C505661:FASLG protein, human; D053222:Fas Ligand Protein; D008562:Membrane Glycoproteins; D011506:Proteins; D051636:X-Linked Inhibitor of Apoptosis Protein; C496866:XIAP protein, human; D019014:fas Receptor