Expression profiling of cumulus cells reveals functional changes during ovulation and central roles of prostaglandin EP2 receptor in cAMP signaling

Abstract

To understand the role of prostaglandin (PG) receptor EP2 ( Ptger2) signaling in ovulation and fertilization, we investigated time-dependent expression profiles in wild-type (WT) and Ptger2 −/− cumuli before and after ovulation by using microarrays. We prepared cumulus cells from mice just before and 3, 9 and 14 h after human chorionic gonadotropin injection. Key genes including cAMP-related and epidermal growth factor (EGF) genes, as well as extracellular matrix- (ECM-) related and chemokine genes were up-regulated in WT cumuli at 3 h and 14 h, respectively. Ptger2 deficiency differently affected the expression of many of the key genes at 3 h and 14 h. These results indicate that the gene expression profile of cumulus cells greatly differs before and after ovulation, and in each situation, PGE 2-EP2 signaling plays a critical role in cAMP-regulated gene expression in the cumulus cells under physiological conditions.