Babu P S, Danilovich N, Sairam M R
Molecular Reproduction Research Laboratory, Clinical Research Institute of Montréal, Montréal, Québec, Canada H2W 1R7.
Endocrinology. 2001 Jan;142(1):381-9. doi: 10.1210/endo.142.1.7886.
The acquisition of FSH receptor(s) during follicular growth and their coupling to signaling pathways are key events in follicular development and dominance. However, little is known about the precise nature of the FSH receptor(s) involved in the growth-promoting phases of hormone action. To investigate the hormonal regulation of a newly discovered, alternatively spliced, growth factor type 1 receptor (designated FSH-R3) for the hormone, we examined expression in the adult mouse and the effect of PMSG treatment in the immature mouse ovary. Using RT-PCR and primers based on the established sheep ovarian transcript, a part of the FSH-R3 message was amplified only in wild-type (+/+), but not in the FSH-R knockout (-/-), mouse ovary. Semiquantitative RT-PCR using 3'-end primers specific for FSH-R1 (G(s)-coupled) and FSH-R3 indicated expression levels of the latter to be higher when follicular growth was induced by PMSG. Using FSH-R3-specific peptide IgG, FSH-R3 protein was detected by Western blotting in extracts of adult mouse ovary and was localized in granulosa cell membrane of mature follicles. In the immature mouse, levels of FSH-R3 protein that increased after PMSG administration in a time-dependent manner were also localized only on granulosa cell membranes of large follicles. The results reveal for the first time the expression of a different growth-promoting receptor for FSH in the developing and cycling mouse ovary. These observations introduce a new paradigm in the control of ovarian function.
卵泡生长过程中促卵泡激素（FSH）受体的获得及其与信号通路的偶联是卵泡发育和优势化的关键事件。然而，对于激素作用促进生长阶段所涉及的FSH受体的确切性质知之甚少。为了研究一种新发现的、选择性剪接的激素1型生长因子受体（命名为FSH-R3）的激素调节，我们检测了其在成年小鼠中的表达以及孕马血清促性腺激素（PMSG）处理对未成熟小鼠卵巢的影响。使用基于已确定的绵羊卵巢转录本的逆转录聚合酶链反应（RT-PCR）和引物，仅在野生型（+/+）小鼠卵巢中扩增出部分FSH-R3信息，而在FSH受体敲除（-/-）小鼠卵巢中未扩增出。使用对FSH-R1（与G(s)偶联）和FSH-R3特异的3'端引物进行半定量RT-PCR表明，当用PMSG诱导卵泡生长时，后者的表达水平更高。使用FSH-R3特异性肽IgG，通过蛋白质印迹法在成年小鼠卵巢提取物中检测到FSH-R3蛋白，并定位在成熟卵泡的颗粒细胞膜上。在未成熟小鼠中，PMSG给药后以时间依赖性方式增加的FSH-R3蛋白水平也仅定位在大卵泡的颗粒细胞膜上。结果首次揭示了在发育中和周期性变化的小鼠卵巢中存在一种不同的促进生长的FSH受体。这些观察结果为卵巢功能的控制引入了一个新的范例。
