title: Phospholipase A(2) and cyclooxygenase gene expression in human preimplantation embryos.
abstract: Phospholipase A(2) (PLA(2)) and cyclooxygenase (COX) are two key enzymes in PG synthesis; the latter has two forms, COX-1 and COX-2. mRNA was extracted from single preimplantation embryos and examined for PLA(2), COX-1, and COX-2 gene expression by RT-PCR to investigate whether PLA(2) and COX genes are expressed in human preimplantation conceptuses from zygote to blastocyst stage and to compare COX-1 and COX-2 gene expression within the same stage of embryonic development. Expression of PLA(2), COX-1, and COX-2 was detected in 48, 37, and 45%, respectively, of total embryos examined. COX-1 was expressed in approximately 66% of early human preimplantation embryos from zygote to two-cell stage, whereas COX-2 was expressed in about 58% of later stage embryos from eight-cell to blastocyst stage (P < 0.05). Furthermore, COX-2 mRNA and protein were localized to trophectoderm in blastocyst stage embryos. In conclusion, PLA(2), COX-1, and COX-2 are expressed during early human embryonic development and may contribute to the production of PGs such as PGE(2) in human embryogenesis. COX-1 and COX-2 are differentially expressed, with COX-2 being primarily expressed by trophectoderm in late-stage human preimplantation embryos, which may promote embryonic differentiation and implantation.
authors.affiliation: Department of Gynecology and Obstetrics, Polan Laboratory, Stanford University School of Medicine, 300 Pasteur Drive, Room HH333, Stanford, CA 94305, USA. hongbo99@leland.stanford.edu
authors.forename: Hongbo
authors.initials: H
authors.lastname: Wang
authors.forename: Yan
authors.initials: Y
authors.lastname: Wen
authors.forename: Stephen
authors.initials: S
authors.lastname: Mooney
authors.forename: Barry
authors.initials: B
authors.lastname: Behr
authors.forename: Mary Lake
authors.initials: ML
authors.lastname: Polan
mesh_terms: D001755:Blastocyst / Q000502:physiology*; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D005314:Embryonic and Fetal Development; D015870:Gene Expression; D006801:Humans; D007527:Isoenzymes / Q000235:genetics*; D008565:Membrane Proteins; D010741:Phospholipases A / Q000235:genetics*; D011451:Prostaglandin-Endoperoxide Synthases / Q000235:genetics*; D012333:RNA, Messenger / Q000378:metabolism
chemical_list: D007527:Isoenzymes; D008565:Membrane Proteins; D012333:RNA, Messenger; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; C496511:PTGS1 protein, human; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases; D010741:Phospholipases A