1. Molecular mechanisms of insulin-like growth factor 1 promoted synthesis and retention of hyaluronic acid in porcine oocyte-cumulus complexes.
- Author
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Nemcová L, Nagyová E, Petlach M, Tománek M, and Procházka R
- Subjects
- Animals, Cell Proliferation drug effects, Cells, Cultured, Cyclic AMP biosynthesis, Cyclic AMP-Dependent Protein Kinases metabolism, Female, Follicle Stimulating Hormone pharmacology, Glucuronosyltransferase genetics, Glucuronosyltransferase metabolism, Granulosa Cells cytology, Granulosa Cells metabolism, Hyaluronan Synthases, Mitogen-Activated Protein Kinase 3 metabolism, Oocytes metabolism, Phosphatidylinositol 3-Kinases metabolism, Phosphorylation drug effects, Proto-Oncogene Proteins c-akt metabolism, Swine, Granulosa Cells drug effects, Hyaluronic Acid biosynthesis, Hyaluronic Acid metabolism, Insulin-Like Growth Factor I pharmacology, Oocytes drug effects
- 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.
- Published
- 2007
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