Expression And Regulation Of Prostaglandin E Synthase In Mouse Ovary

Prostaglandin E synthase (PGES) is the terminal rate-limiting enzyme for PGE2 synthesis, which catalyzes the conversion of PGH2 into PGE2. There exists two isoforms of PGES, glutathione-dependent membrane-associated PGES (mPGES) and glutathione-dependent cytosolic PGES (cPGES). PGES has been proved to be important for mouse implantation and decidualization, and for ovulation in bovine. The aim of this study was to investigate the expression of mPGES and cPGES in mouse ovary during the sexual maturation, ovulation, and formation and regression of corpus luteum by immunohistochemistry and in situ hybridization.mPGES mRNA was expressed in granulosa cells of primary and secondary follicles during ovulation induced by gonadotropin. A high level of mPGES mRNA was seen 3 h after PMSG treatment. mPGES mRNA signals were also seen 3 h after hCG treatment. mPGES mRNA was maily located in granulosa cells including cumulus cells in follicles. A high level of mPGES immunostaining was observed in the ovary in the 21 days old mouse. mPGES immunostaining became slightly weaker 12h after PMSG treatment. The highest level of mPGES immunostaining was detected 3 h after hCG treatment.cPGES mRNA was strongly expressed in granulosa cells of primary and secondary follicles. There was a decline in cPGES mRNA expression 48 h after PMSG treatment. This decline went on until 11 h after hCG treatment. cPGES mRNA was also found in cumulus cells 3 h after hCGtreatment. cPGES mRNA signal was maily located in oocyte cytoplasm and declined at 48 hafter PMSG treatment. No cPGES mRNA signal was detected in granulosa cells. cPGES immunostaining was up-regulated 3 h after hCG treatment and became weaker at 11 h after hCG treatment.There was a high level of mPGES mRNA in the corpus luteum on days 2 and 3 after ovulation. mPGES immunostaining was detectable in corpus luteum on days 1-3 after hCG treatment, and increased from day 9 after hCG treatment.cPGES mRNA signals were strongly detected in corpus luteum on day 1 after ovulation and reached its peak on days 2-3 after ovulation. cPGES immunostaining was similar to mPGES in the corpus luteum.These results suggest that mPGES and cPGES may be involved in follicle development, ovulation, and formation and regression of corpus luteum in mouse.Master Candidate: Sun TongMajor: Basic Veterinary Science Supervisor: Yang Zeng-Ming...