title: Positive feedback loop between prostaglandin E2 and EGF-like factors is essential for sustainable activation of MAPK3/1 in cumulus cells during in vitro maturation of porcine cumulus oocyte complexes.
abstract: During in vitro maturation of porcine cumulus-oocyte complexes (COCs), follicle-stimulating hormone (FSH) increases both prostaglandin E2 (PGE2) production and the expression levels of EGF-like factors. The ligands act on cumulus cells by the autocrine system due to their specific receptors, EP2, EP4, or EGF receptor. When each pathway is suppressed by inhibitors, complete cumulus expansion and oocyte maturation do not occur. In this study, we examined the relationship between both of these pathways in cumulus cells of porcine COCs. When COCs were cultured with FSH, Fshr mRNA expression was immediately decreased within 5 h, whereas Ptger2, Ptger4, and Ptgs2 expression levels were significantly increased in cumulus cells in the culture containing FSH for 5 or 10 h. The PTGS2 inhibitor NS398 significantly suppressed not only PGE2 secretion at any culture time point but also Areg, Ereg, and Tace/Adam17 expression in cumulus cells at 10 and 20 h but not at 1 or 5 h. During the early culture period, phosphorylation of MAPK3 and MAPK1 (MAPK3/1) was not affected by NS398; however, at 10 and 20 h, phosphorylation was suppressed by the drug. Furthermore, down-regulations of MAPK3/1 phosphorylation and expression of the target genes by NS398 was overcome by the addition of either PGE2 or EGF. FSH-induced cumulus expansion and meiotic progression to the MII stage were also suppressed by NS398, whereas these effects were also overcome by addition of either PGE2 or EGF. These results indicated that PGE2 is involved in the sustainable activation of MAPK3/1 in cumulus cells via the induction of EGF-like factor, which is required for cumulus expansion and meiotic maturation of porcine COCs.
authors.affiliation: Laboratory of Animal Physiology, Faculty of Life and Environmental Sciences, Prefectural University of Hiroshima, Shobara, Japan. yamayasu@pu-hiroshima.ac.jp
authors.forename: Yasuhisa
authors.initials: Y
authors.lastname: Yamashita
authors.forename: Minako
authors.initials: M
authors.lastname: Okamoto
authors.forename: Ikko
authors.initials: I
authors.lastname: Kawashima
authors.forename: Tetsuji
authors.initials: T
authors.lastname: Okazaki
authors.forename: Ryo
authors.initials: R
authors.lastname: Nishimura
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Gunji
authors.forename: Mitsugu
authors.initials: M
authors.lastname: Hishinuma
authors.forename: Masayuki
authors.initials: M
authors.lastname: Shimada
mesh_terms: D000818:Animals; D002450:Cell Communication / Q000502:physiology*; D002478:Cells, Cultured; D054885:Cumulus Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D000242:Cyclic AMP / Q000378:metabolism; D051546:Cyclooxygenase 2 / Q000378:metabolism; D015232:Dinoprostone / Q000378:metabolism*; D004815:Epidermal Growth Factor / Q000378:metabolism*; D025461:Feedback, Physiological / Q000502:physiology*; D005260:Female; D005640:Follicle Stimulating Hormone / Q000494:pharmacology; D066298:In Vitro Techniques; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism*; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism*; D023421:Models, Animal; D009578:Nitrobenzenes / Q000494:pharmacology; D009865:Oocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects; D011962:Receptors, FSH / Q000378:metabolism; D018078:Receptors, Prostaglandin E / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology; D013449:Sulfonamides / Q000494:pharmacology; D013552:Swine
chemical_list: D009578:Nitrobenzenes; D011962:Receptors, FSH; D018078:Receptors, Prostaglandin E; D013449:Sulfonamides; C080955:N-(2-cyclohexyloxy-4-nitrophenyl)methanesulfonamide; D004815:Epidermal Growth Factor; D005640:Follicle Stimulating Hormone; D000242:Cyclic AMP; D051546:Cyclooxygenase 2; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D015232:Dinoprostone