Fas-mediated apoptosis of mouse embryo stem cells: Its role during embryonic development

PROBLEM: Fas antigen (APO-1/CD95) can regulate the activity of various cell s during adulthood. This study aimed at determining whether Fas may also be involved in the regulation of very early events such as the embryo preimpl antation stage. METHOD OF STUDY: We used mouse embryo stem (ES) cell line as a model for te sting the effect of Fas crosslinking upon anti-Fas monoclonal antibody (MoA b) treatment. In addition, this treatment was also applied to in-vitro mous e-embryo culture. RESULTS: Flow-cytometry analysis of cultured ES cells demonstrated an incre ase in Fas expression, unchanged in the presence of mouse interleukin-2, wh ile greatly upregulated in the presence of lipopolysaccharide (LPS). As det ermined by various means. ES cells may undergo a Fas-mediated apoptosis, sl ightly but significantly intensified by the addition of LPS to cell culture s. We also report that anti-Fas MoAb directly inhibited two-cell stage mous e-embryo (preimplantation) development in in-vitro culture conditions. CONCLUSION: These data suggest a novel mechanism controlling the regulation of physiological cell turnover as well as blastocyst implantation in early embryo development.