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.