title: Molecular mechanisms of insulin-like growth factor 1 promoted synthesis and retention of hyaluronic acid in porcine oocyte-cumulus complexes.
abstract: The purpose of the present study was to elucidate signaling pathways by which insulin like-growth factor 1 (IGF1) promotes FSH-stimulated synthesis and retention of hyaluronic acid (HA) in pig oocyte-cumulus complexes (OCCs) cultured in serum-free medium. We found that IGF1 had no effects on FSH-stimulated production of cAMP and activation of protein kinase A in the OCCs. Immunoblotting with phospho-specific antibodies showed that FSH moderately phosphorylated v-akt murine thymoma viral oncogene homolog (AKT) and mitogen-activated kinase 3 and 1 (MAPK3/1) in cumulus cells. The exposure of OCCs to both FSH and IGF1 resulted in a significant (P < 0.05) increase in AKT and MAPK3/1 phosphorylation. An inhibitor of phosphoinositide-3-kinase (PIK3), LY 294002, significantly (P < 0.05) reduced the IGF1-enhanced phosphorylation of AKT, and inhibitors of AKT (SH6) and MAPK3/1 (U0126) significantly (P < 0.05) decreased the synthesis and retention of HA stimulated by concomitant exposure of OCCs to both FSH and IGF1. The IGF1-promoted synthesis of HA was not accompanied by an increase in the relative abundance of hyaluronan synthase 2 (HAS2) mRNA in the cumulus cells. We conclude that IGF1 promotes the FSH-stimulated synthesis and retention of HA in pig OCCs by PIK3/AKT- and MAPK3/1-dependent mechanisms.
authors.affiliation: Academy of Sciences of the Czech Republic, Institute of Animal Physiology and Genetics, Libechov 277 21, Czech Republic.
authors.forename: Lucie
authors.initials: L
authors.lastname: Nemcová
authors.forename: Eva
authors.initials: E
authors.lastname: Nagyová
authors.forename: Michal
authors.initials: M
authors.lastname: Petlach
authors.forename: Milan
authors.initials: M
authors.lastname: Tománek
authors.forename: Radek
authors.initials: R
authors.lastname: Procházka
mesh_terms: D000818:Animals; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000096:biosynthesis; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism; D005260:Female; D005640:Follicle Stimulating Hormone / Q000494:pharmacology; D014453:Glucuronosyltransferase / Q000235:genetics / Q000378:metabolism; D006107:Granulosa Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D000076002:Hyaluronan Synthases; D006820:Hyaluronic Acid / Q000096:biosynthesis* / Q000378:metabolism*; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology*; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D009865:Oocytes / Q000187:drug effects* / Q000378:metabolism; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D013552:Swine
chemical_list: D007334:Insulin-Like Growth Factor I; D005640:Follicle Stimulating Hormone; D006820:Hyaluronic Acid; D000242:Cyclic AMP; D014453:Glucuronosyltransferase; D000076002:Hyaluronan Synthases; D019869:Phosphatidylinositol 3-Kinases; D051057:Proto-Oncogene Proteins c-akt; D017868:Cyclic AMP-Dependent Protein Kinases; D048052:Mitogen-Activated Protein Kinase 3