HCG up-regulates survivin mRNA in human granulosa cells.

The apoptosis of granulosa cells is involved in follicular atresia and degeneration of the corpus luteum. The mechanisms that regulate follicular atresia and luteal degeneration remain obscure. Survivin is a member of the family of inhibitors of apoptosis protein that is expressed during fetal development and in cancer tissues. The present study investigates the expression of survivin, as well as its regulation and function in granulosa cells. We identified survivin at the protein level in granulosa cells and detected not only survivin but also splice-variant transcripts in human and mouse granulosa-luteal cells. One-step real-time PCR analysis revealed that HCG increases the amount of survivin mRNA expressed in cultured human granulosa cells. These results suggest that survivin is involved in supporting luteal function, and that HCG contributes to this role.