title: Signaling pathways regulating FSH- and amphiregulin-induced meiotic resumption and cumulus cell expansion in the pig.
abstract: To define signaling pathways that drive FSH- and epidermal growth factor (EGF)-like peptide-induced cumulus expansion and oocyte meiotic resumption, in vitro cultured pig cumulus-oocyte complexes were treated with specific protein kinase inhibitors. We found that FSH-induced maturation of oocytes was blocked in germinal vesicle (GV) stage by protein kinase A (PKA), MAPK14, MAPK3/1, and EGF receptor (EGFR) tyrosine kinase inhibitors (H89, SB203580, U0126, and AG1478 respectively) whereas phosphoinositide-3-kinase/v-akt murine thymoma viral oncogene homolog (PI3K/AKT) inhibitor (LY294002) blocked maturation of oocytes in metaphase I (MI). Amphiregulin (AREG)-induced maturation of oocytes was efficiently blocked in GV by U0126, AG1478, and low concentrations of LY294002; H89, SB203580, and high concentrations of LY294002 allowed the oocytes to undergo breakdown of GV and blocked maturation in MI. Both FSH- and AREG-induced cumulus expansion was incompletely inhibited by H89 and completely inhibited by SB203580, U0126, AG1478, and LY294002. The inhibitors partially or completely inhibited expression of expansion-related genes (HAS2, PTGS2, and TNFAIP6) with two exceptions: H89 inhibited only TNFAIP6 expression and LY294002 increased expression of PTGS2. The results of this study are consistent with the idea that PKA and MAPK14 pathways are essential for FSH-induced transactivation of the EGFR, and synthesis of EGF-like peptides in cumulus cells and MAPK3/1 is involved in regulation of transcriptional and posttranscriptional events in cumulus cells required for meiotic resumption and cumulus expansion. PI3K/AKT signaling is important for regulation of cumulus expansion, AREG-induced meiotic resumption, and oocyte MI/MII transition. The present data also indicate the existence of an FSH-activated and PKA-independent pathway involved in regulation of HAS2 and PTGS2 expression in cumulus cells.
authors.affiliation: Laboratory of Developmental Biology, , Institute of Animal Physiology and Genetics, Academy of Sciences of the Czech Republic, Rumburska 89, 277 21 Libechov, Czech Republic. prochazka@iapg.cas.cz
authors.forename: R
authors.initials: R
authors.lastname: Prochazka
authors.forename: M
authors.initials: M
authors.lastname: Blaha
authors.forename: L
authors.initials: L
authors.lastname: Nemcova
mesh_terms: D066258:Amphiregulin; D000818:Animals; D054885:Cumulus Cells / Q000502:physiology*; D017868:Cyclic AMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors / Q000502:physiology; D051546:Cyclooxygenase 2 / Q000235:genetics; D066246:ErbB Receptors / Q000502:physiology; D005260:Female; D005640:Follicle Stimulating Hormone / Q000494:pharmacology*; D005786:Gene Expression Regulation / Q000502:physiology; D014453:Glucuronosyltransferase / Q000235:genetics; D006023:Glycoproteins / Q000494:pharmacology*; D036341:Intercellular Signaling Peptides and Proteins / Q000494:pharmacology*; D008540:Meiosis / Q000187:drug effects* / Q000502:physiology; D048308:Mitogen-Activated Protein Kinase 14 / Q000037:antagonists & inhibitors / Q000502:physiology; D009865:Oocytes / Q000187:drug effects / Q000502:physiology; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology*; D034421:Sus scrofa / Q000502:physiology*
chemical_list: D066258:Amphiregulin; D006023:Glycoproteins; D036341:Intercellular Signaling Peptides and Proteins; D047428:Protein Kinase Inhibitors; D005640:Follicle Stimulating Hormone; D051546:Cyclooxygenase 2; D014453:Glucuronosyltransferase; D066246:ErbB Receptors; D017868:Cyclic AMP-Dependent Protein Kinases; D048308:Mitogen-Activated Protein Kinase 14