Cyclooxygenase-2-derived endogenous prostacyclin enhances mouse embryo hatching
Source: Human Reproduction, Volume 19, Number 12, December 2004 , pp. 2900-2906(7)
Publisher: Oxford University Press
Abstract:INTRODUCTION: The role of prostaglandins (PGs) in embryo hatching remains controversial. In addition, there is no direct evidence that mouse embryos synthesize PGs. METHODS: The effects of endogenous PG on mouse embryo hatching were evaluated by blocking endogenous PG synthesis with indomethacin. Specific cyclooxygenase (COX) inhibitors were used to identify the role of COX-1- and COX-2-derived PGs. An eicosanoid profile was generated by incubating blastocysts with [3H]arachidonic acid and analysing the metabolites by high performance liquid chromatography. The expression and the localization of COX-1, COX-2 and prostacyclin synthase (PGIS) were examined by western blot analysis and immunohistochemistry. RESULTS: The hatching of embryos cultured in 30 l of protein-free medium was blocked by indomethacin (P=0.007) or a selective COX-2 inhibitor (P=0.004). Adding back iloprost, a prostacyclin analogue, abolished the effects of the COX-2 inhibitor. Prostacyclin was the most abundant PG produced by mouse blastocysts, which expressed COX-1, COX-2 and PGIS. COX-1, COX-2 and PGIS were expressed in 4-cell stage embryos and beyond; they were present in the inner cell mass and the trophectoderm of the blastocysts. CONCLUSION: Mouse embryos express COX-1, COX-2 and PGIS which catalyse the formation of PGI<inf>2</inf>; COX-2-derived PGI<inf>2</inf> plays a critical role in embryo hatching.
Document Type: Research article
Affiliations: 1: Department of Obstetrics and Gynecology, 2: Obstetrical and Gynecological Associates, Houston, TX, USA 3: Vascular Biology Center, Institute of Molecular Medicine and Division of Hematology, Department of Internal Medicine, University of Texas Health Science Center-Houston and
Publication date: 2004-12-01
- Human Reproduction features full-length, peer-reviewed papers reporting original research, clinical case histories, as well as opinions and debates on topical issues. Papers published cover the scientific and medical aspects of reproductive physiology and pathology, endocrinology, andrology, gonad function, gametogenesis, fertilization, embryo development, implantation, pregnancy, genetics, genetic diagnosis, oncology, infectious disease, surgery, contraception, infertility treatment, psychology, ethics and social issues. The highest scientific and editorial standard is maintained throughout the journal along with a rapid rate of publication.