BMP-4 inhibits follicle-stimulating hormone secretion in ewe pituitary
BMP-4 inhibits follicle-stimulating hormone secretion in ewe pituitary
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DOI：
10.1677/joe.1.05988
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发表时间：
2005-07-01
影响因子：
4
通讯作者：
Taragnat, C
中科院分区：
文献类型：
--
作者：
Faure, MO;Nicol, L;Taragnat, C
Activins and inhibins, members of the transforming growth factor-beta family are able to stimulate and inhibit, respectively, FSH synthesis and release. Other members of this superfamily, the bone rnorphogenetic proteins (BMPs), may also affect FSH synthesis in the mouse. The aim of this work was to determine whether BMPs are expressed in the ovine pituitary and whether they play a role in the regulation of FSH release. The mRNAs encoding BMP-2, BMP-4, BMP-7 and the oocyte-derived growth factor, growth differentiation factor (GDF)-9 were detected it) the pituitaries of cyclic ewes by reverse-transcriptase PCR, as well as the mRNAs encoding the BMP type I receptors, BMPR-IA (activin-receptor-like kinase (ALK)-3) and BMPR-1B (ALK-6), and type 11 receptors (BMPR-II). Immunolabeling of pituitary, sections revealed the presence of BMPR-IA (ALK-3) and BMPR-II in gonadotrope cells. To investigate the potential effects of BMPs on FSH secretion, ewepituitary cell cultures were treated with BMP-4 (10(-11) M to 10(-9) M) for 48 h. Interestingly, FSH release was decreased in a dose-dependent manner. At 10(-9) M BMP-4 both FSH concentration and FSH beta mRNA expression were reduced by 40% of control values. In contrast, there was no inhibitory effect on either LH or LHP mRNA expression. A similar result was found with BMP-6. BMP-4 triggered the phosphorylation of Smad1, suggesting that the effect of BMP-4 on FSH secretion is due to the activation of the BMPs signaling pathway. Furthermore, BMP-4 blocked the stimulatory effect of activin on both FSH release and FSH beta mRNA and amplified the suppression of FSH release and FSH beta mRNA levels induced by 17 beta-estradiol. These results indicate that a functional BMP system operates within the sheep pituitary, at least in vitro, to decrease FSH release and to modulate the effect of activin.
