Effects of ghrelin on activation of Akt1 and ERK1/2 pathways during in vitro maturation of bovine oocytes.
Zygote
; 25(2): 183-189, 2017 Apr.
Article
em En
| MEDLINE
| ID: mdl-28264754
ABSTRACT
The purpose of this study was to investigate the possible molecular pathways through which ghrelin accelerates in vitro oocyte maturation. Bovine cumulus-oocyte complexes (COCs), after 18 or 24 h maturation in the absence or the presence of 800 pg ml-1 of acylated ghrelin were either assessed for nuclear maturation or underwent in vitro fertilization in standard media and putative zygotes were cultured in vitro for 8 days. In a subset of COCs the levels of phosphorylated Akt1 and ERK1/2 (MAPK1/3) were assessed at the 0th, 6th, 10th, 18th and 24th hours of in vitro maturation (IVM). At 18 and 24 h no difference existed in the proportion of matured oocytes in the ghrelin-treated group, while in the control group more (P < 0.05) matured oocyte were found at 24 h. Oocyte maturation for 24 h in the presence of ghrelin resulted in substantially reduced (P < 0.05) blastocyst yield(16.3%) in comparison with that obtained after 18 h (30.0%) or to both control groups (29.3% and 26.9%, for 18 and 24 h in maturation, respectively). Ghrelin-treated oocytes expressed lower Akt1 phosphorylation rate at the 10th hour of IVM, and higher ERK1/2 at the 6th and 10th hours of IVM compared with controls. In cumulus cells, at the 18th and 24th hours of IVM Akt1 phosphorylation rate was higher in ghrelin-treated oocytes. Our results imply that ghrelin acts in a different time-dependent manner on bovine oocytes and cumulus cells modulating Akt1 and ERK1/2 phosphorylation, which brings about acceleration of the oocyte maturation process.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Oócitos
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Regulação da Expressão Gênica
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Sistema de Sinalização das MAP Quinases
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Proteínas Proto-Oncogênicas c-akt
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Grelina
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Técnicas de Maturação in Vitro de Oócitos
Limite:
Animals
Idioma:
En
Ano de publicação:
2017
Tipo de documento:
Article