Temporal and spatial patterns of expression of inhibitors of apoptosis in human placentas.
The apoptosis cascade that plays a central role in normal and pathological processes is strictly controlled, in part by newly described members of the inhibitor of apoptosis (IAP) family (HIAP-1, HIAP-2, XIAP, NAIP, Survivin, and Livin). Here, we report the expression of IAP mRNAs and proteins in early and late gestation human placentas, term cytotrophoblast cells, and two choriocarcinoma cell lines, JEG-3 and Jar. Reverse transcriptase-polymerase chain reaction identified mRNAs derived from all of the currently known IAP genes in all samples. Analysis by immunoblotting revealed that IAP proteins are present in early and late gestation human placentas and that levels of IAPs are not identical in normal and transformed trophoblast cells. Immunohistochemical experiments performed on paraformaldehyde-fixed tissue sections taken from early and late stages of pregnancy demonstrated that expression patterns differed according to cell lineage and stage of cell differentiation. The results of this study are consistent with the postulate that IAP proteins have critical roles in placental cell survival and suggest that specific apoptosis inhibitors may protect normal and transformed trophoblast cells from cell death.
Ka
Hakhyun
H
Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, Kansas 66160, USA.
Hunt
Joan S
JS
D048868:Adaptor Proteins, Signal Transducing; D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000378:metabolism; D005260:Female; D005786:Gene Expression Regulation; D006801:Humans; D051034:Inhibitor of Apoptosis Proteins; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism; D051616:Neuronal Apoptosis-Inhibitory Protein; D010920:Placenta / Q000166:cytology / Q000378:metabolism*; D011247:Pregnancy; D011506:Proteins / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D000077022:Survivin; D014327:Trophoblasts / Q000166:cytology / Q000378:metabolism; D014407:Tumor Cells, Cultured; D051636:X-Linked Inhibitor of Apoptosis Protein
D048868:Adaptor Proteins, Signal Transducing; C107489:BIRC5 protein, human; C419866:BIRC7 protein, human; D002352:Carrier Proteins; D004791:Enzyme Inhibitors; D051034:Inhibitor of Apoptosis Proteins; D008869:Microtubule-Associated Proteins; C496800:NAIP protein, human; D009363:Neoplasm Proteins; D009419:Nerve Tissue Proteins; D051616:Neuronal Apoptosis-Inhibitory Protein; D011506:Proteins; D012333:RNA, Messenger; D000077022:Survivin; D051636:X-Linked Inhibitor of Apoptosis Protein; C496866:XIAP protein, human