Cyclic guanosine monophosphate does not inhibit gonadotropin-induced activation of mitogen-activated protein kinase 3/1 in pig cumulus-oocyte complexes

0441646 - ÚŽFG 2015 RIV US eng J - Journal Article
Blaha, Milan - Němcová, Lucie - Procházka, Radek
Cyclic guanosine monophosphate does not inhibit gonadotropin-induced activation of mitogen-activated protein kinase 3/1 in pig cumulus-oocyte complexes.
Reproductive Biology and Endocrinology. Roč. 13, č. 1 (2015). E-ISSN 1477-7827
R&D Projects: GA ČR GAP502/11/0593; GA MZe QI101A166
Institutional support: RVO:67985904
Keywords : pig * oocyte * cGMP
Subject RIV: EB - Genetics ; Molecular Biology
Impact factor: 2.147, year: 2015

Background: Recent results indicate a key role for cyclic guanosine monophosphate (cGMP) in the regulation of oocyte meiotic arrest in preovulatory mammalian follicles. The aim of our study was to determine whether the resumption of oocyte meiosis and expansion of cumulus cells in isolated pig cumulus-oocyte complexes (COCs) can be blocked by a high intracellular concentration of cGMP, and whether this effect is mediated by a cGMP-dependent inhibition of mitogen-activated protein kinase 3/1 (MAPK3/1). Results: The COCs expressed NPPC and NPR2, the key components of cGMP synthesis, and produced a large amount of cGMP upon stimulation with exogenous CNP, which lead to a significant (P < 0.05) delay in oocyte meiotic resumption. The COCs also responded to cGMP analogues by inhibiting the resumption of oocyte meiosis. The inhibitory effect of cGMP on meiotic resumption was reversed by stimulating the COCs with FSH. However, high concentration of intracellular cGMP was not able to suppress FSH-induced activation of MAPK3/1 in cumulus cells, cumulus expansion and expression of expansion-related genes (P > 0.05). Conclusions: The findings of this study indicate that high cGMP concentrations inhibit the maturation of pig oocytes in vitro but the inhibitory mechanism does not involve the suppression of MAPK3/1 activation in cumulus cells.
Permanent Link: http://hdl.handle.net/11104/0244648