Transforming growth factor β1 regulates follistatin mRNA expression during in vitro bovine granulosa cell differentiation
In order to test the hypothesis that transforming growth factor β (TGF-β) acts by FS regulation on bovine granulosa cells in in vitro differentiation, we analyzed the effect of TGF-β1 on follistatin mRNA expression in three differentiation states of bovine granulosa cells. We showed a positive regul...
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Autores principales: | , , , , , , |
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Formato: | JOUR |
Materias: | |
Acceso en línea: | http://hdl.handle.net/20.500.12110/paper_00219541_v207_n1_p40_Fazzini |
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Sumario: | In order to test the hypothesis that transforming growth factor β (TGF-β) acts by FS regulation on bovine granulosa cells in in vitro differentiation, we analyzed the effect of TGF-β1 on follistatin mRNA expression in three differentiation states of bovine granulosa cells. We showed a positive regulation of FS mRNA after TGF-β1 (1 ng/ml) treatment of freshly isolated granulosa cells from small-medium antral follicles (2-8 mm). This effect was abolished by the addition of exogenous follistatin (100 ng/ml), suggesting that this effect could be mediated by activin. Although these cells showed a similar effect on FS mRNA expression after treatment with activin-A, a soluble form of activin receptor type IIA was unable to inactivate the TGF-β effect. When we tested the TGF-β effect on FS mRNA in different granulosa cell states, TGF-β1 regulation was associated with progesterone production only in freshly isolated cells. The amount of total activin-A produced by first passage cells (dedifferentiated cells), was ten times smaller than the one measured in a conditioned medium from freshly isolated cells (mature cells). The TGF-β1-dependent FS mRNA expression persisted in first passage cells without changes with FS addition. On the other hand, the BGC-1 granulosa cell line (immature cells) produced large amounts of activin-A regulated by TGF-β1 and an invariable steady state of FS mRNAs. In summary, our results showed that FS mRNA expression is regulated by TGF-β1 independently of activin effects in differentiated granulosa cells. © 2005 Wiley-Liss, Inc. |
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