title: Peroxiredoxin 6 is upregulated in bovine oocytes and cumulus cells during in vitro maturation: role of intercellular communication.
abstract: Peroxiredoxins are peroxidases involved in antioxidant defense and intracellular signaling. Expression of transcripts coding for peroxiredoxin 6 (PRDX6) has been previously described to be upregulated in oocytes after in vitro maturation, a period during which general transcription decreases dramatically in oocytes. The aim of the present work was to evaluate PRDX6 regulation in bovine cumulus-oocyte complexes in relation to maturation and intercellular communication. PRDX6 expression was analyzed by reverse transcription-PCR and Western blotting in oocytes and cumulus cells before and after in vitro maturation. PRDX6 was found to be upregulated at the mRNA and protein levels in both cell types after maturation. The effect of paracrine and gap junctional communication on PRDX6 expression was then assessed by culturing cumulus clusters in the presence or absence of denuded oocytes. While PRDX6 upregulation in oocytes required intact cumulus-oocyte junctions, the presence of denuded oocytes was necessary but sufficient for the upregulation to occur in cumulus cells. Finally, the influence of recombinant mouse growth differentiation factor-9 (GDF-9) on PRDX6 expression in cumulus cells was studied. GDF-9 induced cumulus expansion and PRDX6 upregulation in bovine cumulus clusters. Altogether, our data suggest that PRDX6 upregulation in cumulus-oocyte complexes during in vitro maturation is mutually regulated by both cell types: PRDX6 upregulation in oocytes would require gap junctions with cumulus cells, while upregulation in cumulus would depend on secretion of oocyte paracrine factor(s) with GDF-9 being a likely candidate.
authors.affiliation: Unité des Sciences vétérinaires, Institut des Sciences de la Vie, Université Catholique de Louvain, B-1348 Louvain-la-Neuve, Belgium.
authors.forename: Gregory
authors.initials: G
authors.lastname: Leyens
authors.forename: Benjamin
authors.initials: B
authors.lastname: Verhaeghe
authors.forename: Marie
authors.initials: M
authors.lastname: Landtmeters
authors.forename: Joëlle
authors.initials: J
authors.lastname: Marchandise
authors.forename: Bernard
authors.initials: B
authors.lastname: Knoops
authors.forename: Isabelle
authors.initials: I
authors.lastname: Donnay
mesh_terms: D000818:Animals; D055430:Bone Morphogenetic Protein 15; D002417:Cattle; D002450:Cell Communication / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D005260:Female; D017629:Gap Junctions / Q000502:physiology; D055429:Growth Differentiation Factor 9; D036341:Intercellular Signaling Peptides and Proteins / Q000008:administration & dosage / Q000494:pharmacology; D009865:Oocytes / Q000378:metabolism*; D009866:Oogenesis / Q000502:physiology*; D009994:Osmolar Concentration; D006080:Ovarian Follicle / Q000166:cytology* / Q000378:metabolism*; D019899:Paracrine Communication / Q000502:physiology; D010544:Peroxidases / Q000378:metabolism*; D054465:Peroxiredoxin VI; D054464:Peroxiredoxins; D020033:Protein Isoforms / Q000378:metabolism; D015854:Up-Regulation
chemical_list: C525902:Bmp15 protein, mouse; D055430:Bone Morphogenetic Protein 15; C525898:Gdf9 protein, mouse; D055429:Growth Differentiation Factor 9; D036341:Intercellular Signaling Peptides and Proteins; D020033:Protein Isoforms; D010544:Peroxidases; D054465:Peroxiredoxin VI; D054464:Peroxiredoxins; C515983:Prdx6 protein, mouse