| The receptor Fas and its ligand, FasL, are implicated in apoptosis of luteal cells during regression of the corpus luteum (CL). In some cell types, cytokeratin (CK) 8/18 filaments impair FasL-induced apoptosis. Here, we determined if genetic over-expression of CK18 filaments in luteal cells similarly prevents FasL-induced apoptosis. Luteal cell cultures were prepared from early and late stage bovine CL (day 5 and days 16-18 post-ovulation, respectively). The cells were transduced with media, mock vector containing GFP, or a CK18-containing vector, and then exposed to a cytokine cocktail containing FasL for 24 hours. Transduction of luteal cells with CK18 vector resulted in CK18 aggregates rather than filaments. The aggregates did not affect surface expression of Fas or progesterone production. Moreover, the CK18 aggregates did not prevent FasL-induced apoptosis. Thus, while successful in transducing primary cultures of bovine luteal cells with CK18, aggregation of CK failed to prevent FasL-induced apoptosis. |
