Group IVA phospholipase A₂ optimizes ovulation and fertilization in rodents through induction of and metabolic coupling with prostaglandin endoperoxide synthase 2.

Kurusu, Shiro; Sapirstein, Adam; Bonventre, Joseph V.

Female mice lacking group IVA phospholipase A2 (Pla2g4a-/-) have a smaller litter size, which is due, in part, to defective implantation. We examined PLA2G4A dependence of the processes of ovulation and fertilization. Following induction of ovulation by equine chorionic gonadotropin (eCG)/human CG (hCG) treatment and mating, ovulation and fertilization rates were reduced significantly in Pla2g4a-/-mice as compared to wild-type littermates. Human CG triggered robust ovarian prostaglandin (PG) E2 production in the preovulatory period that was significantly attenuated in Pla2g4a-/- mice. Human CG transiently enhanced ovarian expression of PLA2G4A and prostaglandin endoperoxide synthase 2 (PTGS2) in wild-type mice. This PTGS2 induction was decreased in Pla2g4a-/- mice and also in immature rats treated with the PLA2G4A inhibitor, archidonyl trifluoromethyl ketone. A close spatiotemporal association of PLA2G4A with PTGS2 was found in mouse and rat preovulatory follicles examined by immunohistochemistry. Less association was observed with 4 other forms of PLA2. Our data strongly suggest that PLA2G4A amplifies hCG induction of PTGS2 and colocalizes with the induced PTGS2, thus contributing to robust PG production required for optimal ovulation and fertilization in rodents.

RODENT reproduction; PHOSPHOLIPASE A2; INDUCED ovulation; RODENT physiology; LABORATORY rodents; PROSTAGLANDINS

FASEB Journal, 2012, Vol 26, Issue 9, p3800

0892-6638

Academic Journal

10.1096/fj.12-203968