EXPRESSION OF AN FSH ANALOG WITH A REROUTED SECRETION PATTERN IN TRANSGENIC MICE

描述(由申请人提供)：人类脑下垂体激素促黄体生成素和卵泡刺激素是糖蛋白异源二聚体家族的一部分，该家族由一个共同的1亚基和一个激素特异性亚基组成。正是亚基决定了每种激素的生物学特异性。这些蛋白质的一个关键特征是它们独特的分泌模式。黄体生成素是通过一种调节的途径释放的，即促分泌剂释放，而卵泡刺激素主要是结构性分泌的。这些途径对于黄体生成素和卵泡刺激素在生殖中的协调作用是必不可少的。确定黄体生成素和卵泡刺激素的分类和贩运的决定因素一直是我的实验室的主要重点。使用转基因的垂体促生长激素来源的GH3细胞，鉴定了一个新的序列，该序列位于黄体生成素亚单位的羧基末端，将黄体生成素引导到调节途径。此外，由FSHβ亚基和该多肽组成的嵌合体被转移到受调控的途径。这项R03试验方案的主要目的是测试这样一种假设，即这种FSH类似物可以在转基因小鼠的脑下垂体中重新路由到受调控的途径。那么，将FSH从正常的结构性分泌引导到调节途径的生理后果是什么？这些实验将使用使用人类FSH野生型或人类FSH类似物转基因的FSH基因敲除小鼠。该模型的优点是可以在没有内源性小鼠卵泡刺激素背景的转基因小鼠中进行分选和功能检测。我们将检查切除的脑下垂体的分泌，以及通过调节途径分泌FSH的转基因小鼠的潜在生理后果。在体内改变垂体促性腺激素的路线的能力代表了性腺功能障碍的一个潜在的重要模型，并为研究人类生殖道的正常和最终的病理生理事件提供了一种新的方法。 公共卫生相关性：这里提出的研究旨在研究FSH和LH的分泌途径与激素功能之间的联系。从我们的工作中获得的数据将有助于理解这些激素和卵泡发育之间的相互作用。此外，性腺功能亢进或性腺功能低下的病理可能是由于脑下垂体异常分泌FSH和/或黄体生成素所致。

DESCRIPTION (provided by applicant): The human pituitary hormones lutropin (LH) and follitropin (FSH) are part of a family of glycoprotein heterodimers comprised of a common 1 subunit and a hormone-specific ¿ subunit. It is the ¿ subunit that determines the biological specificity of each hormone. A critical feature of these proteins is their unique secretory patterns. LH is released through a regulated pathway, i.e., it is released by secretagogue, whereas FSH is primarily secreted constitutively. These routings are essential for the coordinated roles of LH and FSH in reproduction. Identifying the determinants that account for the sorting and trafficking of LH and FSH has been a major focus of my laboratory. Using transfected pituitary somatotrope-derived GH3 cells, a novel sequence at the carboxyl end of the LH¿ subunit directing LH to the regulated pathway was identified. Moreover, a chimera comprised of the FSH¿ subunit and this peptide was diverted to the regulated pathway. The primary objective of this R03 pilot proposal is to test the hypothesis that this FSH analog can be rerouted to the regulated pathway in pituitaries of transgenic mice. Thus, what are the physiological consequences of directing FSH from its normal constitutive secretion to the regulated pathway? These experiments will employ FSH¿ knock-out mice using either the human FSH¿ wild type or the human FSH¿ analog transgenes. The advantage of this model is that the sorting and function can be examined in transgenic mice without the background of endogenous mouse FSH. We will examine the secretion from excised pituitaries and potential physiological consequences for the transgenic mice secreting FSH through the regulated pathway. The ability to reroute the pituitary gonadotropins in vivo represents a potentially important model for gonadal dysfunction and provides a novel way to examine normal and ultimately pathophysiological events in the human reproductive tract. PUBLIC HEALTH RELEVANCE: The studies proposed here are designed to study the link between the secretion pathways of FSH and LH and hormonal function. The data obtained from our work will aid in understanding the interplay between these hormones and the development of the follicle. In addition, pathologies in which there is hyper- or hypogonadism can likely be attributed to aberrant secretion of FSH and/or LH from the pituitary.