Apoptosis in human embryo development: 3. Fas-induced apoptosis in brain primary cultures.
Fas (APO-1/CD95) is an important apoptotic mediator for both immune and nervous systems. In the present study, we have investigated the expression and function of Fas in human embryonic/fetal brain primary cultures from 12 human embryos and fetuses with gestational ages between 5 to 22 weeks. Anti-Fas fluorescent antibody was used for labeling of Fas positive cells and for quantitation of Fas expression in brain cultures. To demonstrate that Fas receptor is functional in human embryonic/fetal brain cells, anti-Human-Fas monoclonal antibody (0.5 microg/ml) was used to induce apoptosis in brain primary cultures. Apoptosis was investigated by flow-cytometry and fluorescent microscopy using TUNEL and annexin V labeling. Fas was found to be expressed in the embryonic/fetal human primary brain cultures, on neuronal and glial cells or their precursors, varying with gestational ages. Cross-linking of Fas induced apoptosis in brain cultures indicating that Fas receptor functions as a death receptor. We also showed that cell death triggered through Fas receptor was caspase dependent, hence it was blocked by a selective caspase-8 inhibitor (IETD-fmk). These results suggest that Fas is involved in neuronal apoptosis in the developing human brain.
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Division of Cellular and Molecular Medicine, Carol Davila University of Medicine and Pharmacy, 8 Eroilor Sanitari, Bucharest, Romania.
Radu
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Regalia
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Popescu
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D017209:Apoptosis / Q000502:physiology*; D015415:Biomarkers; D001921:Brain / Q000166:cytology* / Q000196:embryology* / Q000502:physiology; D002478:Cells, Cultured; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D005314:Embryonic and Fetal Development; D005333:Fetus; D005434:Flow Cytometry; D005865:Gestational Age; D006801:Humans; D020287:In Situ Nick-End Labeling; D008856:Microscopy, Fluorescence; D009457:Neuroglia / Q000378:metabolism; D009474:Neurons / Q000187:drug effects* / Q000502:physiology; D009842:Oligopeptides / Q000494:pharmacology; D019014:fas Receptor / Q000502:physiology*
D015415:Biomarkers; D015853:Cysteine Proteinase Inhibitors; D009842:Oligopeptides; D019014:fas Receptor; C425644:isoleucyl-glutamyl-threonyl-aspartic acid fluoromethyl ketone