Transforming growth factor-ß signaling participates in the maintenance of the primordial follicle pool in the mouse ovary.
J Biol Chem
; 289(12): 8299-311, 2014 Mar 21.
Article
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| MEDLINE
| ID: mdl-24515103
ABSTRACT
Physiologically, only a few primordial follicles are activated to enter the growing follicle pool each wave. Recent studies in knock-out mice show that early follicular activation depends on signaling from the tuberous sclerosis complex, the mammalian target of rapamycin complex 1 (mTORC1), phosphatase and tensin homolog deleted on chromosome 10, and phosphatidylinositol 3-kinase (PI3K) pathways. However, the manner in which these pathways are normally regulated, and whether or not TGF-ß acts on them are poorly understood. So, this study aims to identify whether or not TGF-ß acts on the process. Ovary organ culture experiments showed that the culture of 18.5 days post-coitus (dpc) ovaries with TGF-ß1 reduced the total population of oocytes and activated follicles, accelerated oocyte growth was observed in ovaries treated with TGF-ßR1 inhibitor 2-(5-chloro-2-fluorophenyl)pteridin-4-yl]pyridin-4-yl-amine (SD208) compared with control ovaries, the down-regulation of TGF-ßR1 gene expression also activated early primordial follicle oocyte growth. We further showed that there was dramatically more proliferation of granulosa cells in SD208-treated ovaries and less proliferation in TGF-ß1-treated ovaries. Western blot and morphological analyses indicated that TGF-ß signaling manipulated primordial follicle growth through tuberous sclerosis complex/mTORC1 signaling in oocytes, and the mTORC1-specific inhibitor rapamycin could partially reverse the stimulated effect of SD208 on the oocyte growth and decreased the numbers of growing follicles. In conclusion, our results suggest that TGF-ß signaling plays an important physiological role in the maintenance of the dormant pool of primordial follicles, which functions through activation of p70 S6 kinase 1 (S6K1)/ribosomal protein S6 (rpS6) signaling in mouse ovaries.
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Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Oócitos
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Ovário
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Proteínas Serina-Treonina Quinases
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Receptores de Fatores de Crescimento Transformadores beta
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Fator de Crescimento Transformador beta1
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Ano de publicação:
2014
Tipo de documento:
Article