Biology of the pituitary gonadotrope cell

身体的器官，如大脑和心脏，是由专门的细胞组成的，这些细胞执行这些器官的必要功能。我们的研究项目致力于更全面地了解垂体中一种叫做促性腺激素的特定细胞类型的功能。脑下垂体是一个位于大脑底部的器官。它由五种类型的细胞组成，每一种细胞都会产生激素，控制身体功能的不同方面，包括繁殖、新陈代谢、生长和我们对压力的反应。******荷尔蒙是在一个器官中产生的化学信使，它通过血液来调节其他器官的活动。在生殖系统中，垂体促性腺激素产生两种激素，分别是促卵泡激素（FSH）和促黄体激素（LH）。一旦从促性腺激素中释放出来，卵泡刺激素和黄体生成素就会进入卵巢和睾丸，在那里它们控制着卵子和精子的发育以及睾酮和雌激素等激素的产生。反过来，FSH和LH的产生和释放由另一种来自大脑的激素控制，叫做促性腺激素释放激素（GnRH）。我们研究计划的一个主要组成部分是致力于了解GnRH如何在促性腺激素细胞中产生这些反应。******除了GnRH外，FSH的产生还受到另一种叫做激活素的激素的强烈控制，这种激素是由促性腺激素细胞本身产生的；至少我们是这么认为的。我们实验室的研究结果表明，一种类似激活素的激素，但不是激活素本身，可能是促卵泡刺激素产生的主要调节剂。在这项发现基金的支持下，我们建议鉴定这种激素，确定它在体内的来源，并了解它是如何控制促性腺激素细胞产生FSH的。******在这项资助中，我们还提议解决关于促性腺细胞的第二组主要未解问题：它们能活多久？它们是像毛囊或肠道细胞一样不断被替换，还是像大脑或心脏细胞一样持续一生？促性腺激素能在成年后被替代吗？如果可以的话，它们是从哪里产生的？******总的来说，从我们的研究项目中产生的知识将为垂体促性腺细胞的正常工作提供更深入的了解，特别是生殖系统。同时，我们的研究结果可以帮助我们了解一些不孕夫妇的问题。

The organs of the body, like the brain and heart, are made up of specialized cells that perform the necessary functions of those organs. Our research program is dedicated to more fully understanding the functions of a specific cell type in the pituitary gland called the gonadotrope. The pituitary gland is an organ that sits at the base of the brain. It is comprised of five cell types, each of which makes hormones that control different aspects of bodily function, including reproduction, metabolism, growth, and our responses to stress. ******Hormones are chemical messengers made in one organ that travel through the bloodstream to regulate the activity of other organs. In the case of the reproductive system, pituitary gonadotropes make two hormones called follicle-stimulating hormone (FSH) and luteinizing hormone (LH). Once released from gonadotropes, FSH and LH travel to the ovaries and testicles were they control the development of the eggs and sperm as well as the production of hormones such as testosterone and estrogen. The production and release of FSH and LH, in turn, are controlled by another hormone from the brain called gonadotropin-releasing hormone (GnRH). A major component of our research program is dedicated to understanding how GnRH produces these responses in gonadotrope cells. ******In addition to GnRH, FSH production is strongly controlled by another hormone called activin, which is made by the gonadotrope cell itself; or so we thought. Research findings from our lab suggest that a hormone similar to activin, but not activin itself, may be a primary regulator of FSH production. With the support of this Discovery Grant, we propose to identify this hormone, to determine where it comes from in the body, and to understand how it controls FSH production by gonadotrope cells.******In this grant, we also propose to address a second set of major unanswered questions about gonadotrope cells: How long do they live? Are they replaced continuously, like cells of the hair follicle or intestines, or can they last a life time, like cells of the brain or heart? Can gonadotropes be replaced in adulthood and, if so, from where do they arise? ******Collectively, the knowledge generated from our research program will provide greater insight into the normal workings of pituitary gonadotrope cells specifically and of the reproductive system more generally. At the same time, our results may help us understand what goes awry in some infertile couples.