TRAIL and KILLER are expressed and induce apoptosis in the murine preimplantation embryo.
TRAIL (tumor necrosis factor [TNF]-related apoptosis-inducing ligand) and KILLER are a death-inducing ligand and receptor pair that belong to the TNF and TNF-receptor superfamilies, respectively. To date, only one apoptosis-inducing TRAIL receptor (murine KILLER [MK]) has been identified in mice, and it is a homologue of human Death Receptor 5. Whereas the expression of other death receptors, such as Fas and TNF receptor 1 have been documented in mammalian preimplantation embryos, no evidence currently demonstrates either the presence or the function of TRAIL and its corresponding death receptor, MK. Using reverse transcription-polymerase chain reaction and confocal immunofluorescent microscopy, we found that both TRAIL and MK are expressed from the 1-cell through the blastocyst stage of murine preimplantation embryo development. These proteins are localized mainly at the cell surface from the 1-cell through the morula stage. At the blastocyst stage, both TRAIL and MK exhibit an apical staining pattern in the trophectoderm cells. Finally, using the TUNEL assay, we demonstrated that MK induces apoptosis in blastocysts sensitized to TRAIL via actinomycin D. Taken together, these data are the first to demonstrate the presence and function of TRAIL and MK, a death-inducing ligand and its receptor, in mammalian preimplantation embryos.
Riley
Joan K
JK
Department of Obstetrics and Gynecology, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
Heeley
Jennifer M
JM
Wyman
Amanda H
AH
Schlichting
Elizabeth L
EL
Moley
Kelle H
KH
D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D051017:Apoptosis Regulatory Proteins; D001755:Blastocyst / Q000166:cytology / Q000502:physiology*; D005260:Female; D005455:Fluorescent Antibody Technique; D018507:Gene Expression Regulation, Developmental; D020287:In Situ Nick-End Labeling; D008024:Ligands; D008562:Membrane Glycoproteins / Q000235:genetics* / Q000378:metabolism; D051379:Mice; D008815:Mice, Inbred Strains; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand; D018124:Receptors, Tumor Necrosis Factor / Q000235:genetics* / Q000378:metabolism; D053221:TNF-Related Apoptosis-Inducing Ligand; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics* / Q000378:metabolism
D051017:Apoptosis Regulatory Proteins; D008024:Ligands; D008562:Membrane Glycoproteins; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand; D018124:Receptors, Tumor Necrosis Factor; D053221:TNF-Related Apoptosis-Inducing Ligand; C505639:TNFRSF10B protein, human; C505653:TNFSF10 protein, human; C505640:Tnfrsf10b protein, mouse; C505654:Tnfsf10 protein, mouse; D014409:Tumor Necrosis Factor-alpha