Biology of the pituitary gonadotrope cell

身体的器官，如大脑和心脏，是由执行这些器官的必要功能的特殊细胞组成的。我们的研究项目致力于更全面地了解脑下垂体中一种称为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。它由五种细胞类型组成，每种细胞产生的激素控制身体功能的不同方面，包括生殖、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，它通过血液流动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，即卵泡刺激素(FSH)和黄体生成素(LH)。促性腺激素和促黄体生成素一旦从促性腺激素释放出来，就会进入卵巢和睾丸，因为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，促性腺激素和促黄体生成素的产生和释放又由大脑中另一种名为促性腺激素释放激素(GnRH)的激素控制。我们研究计划的一个主要组成部分是致力于了解GnRH如何在促性腺细胞中产生这些反应。 除了GnRH，FSH的产生还受到另一种名为激活素的荷尔蒙的强烈控制，这种荷尔蒙是由促性腺激素细胞本身产生的；至少我们是这样认为的。我们实验室的研究结果表明，一种类似激活素的激素，而不是激活素本身，可能是FSH产生的主要调节因素。在发现基金的支持下，我们计划鉴定这种激素，确定它在体内的来源，并了解它是如何控制促性腺细胞产生FSH的。 在这项资助中，我们还建议解决关于促性腺激素细胞的第二个主要悬而未决的问题：它们能活多久？它们是像毛囊或肠道的细胞一样持续更换，还是像大脑或心脏的细胞一样持续一生？促性腺激素能在成年后被替代吗？如果可以，它们是从哪里产生的？ 总而言之，从我们的研究计划中产生的知识将提供更多的洞察，特别是垂体促性腺激素细胞的正常工作，以及更广泛的生殖系统。同时，我们的结果可能会帮助我们了解一些不育夫妇的问题所在。

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.