Imaging Cell Signaling Events During Luteinizing Hormone Pulses

描述（由申请人提供）：随着年龄增长黄体生成素（LH）水平的升高与阿尔茨海默病（AD）的发展有关；来自临床研究的证据表明，使用GnRH拮抗剂Lupron治疗患者可以降低LH水平，减缓AD的进展并改善认知功能。虽然已有研究表明黄体生成素对小鼠大脑和M17细胞中淀粉样蛋白-¿的加工有影响，但令人惊讶的是，对黄体生成素对神经系统的直接影响知之甚少。最近解决这个问题的研究使用了固定浓度的LH，而忽略了LH分泌，特别是女性，具有强烈的脉动性，以及年龄对LH脉冲振幅的影响。在这里，我们建议研究高振幅LH脉冲对M17细胞的影响，M17细胞是一种神经母细胞瘤细胞系，表达LH受体并从其前体加工淀粉样蛋白-¿。将比较年轻妇女和绝经后妇女的黄体生成素受体脉冲特征。我们假设M17神经母细胞瘤细胞暴露于绝经后妇女的LH脉冲，其振幅特征显著增加淀粉样蛋白-¿的分泌，淀粉样蛋白是AD患者大脑中过量出现的一种蛋白质。这些研究还将首次开发与暴露于激素时活细胞中lh介导的信号相关的成像事件的策略。出于几个原因，我们为这个应用程序选择了R03机制。该项目涉及“开发新的研究技术”，这是NICHD R03资助机制的一个目标。支持该R03应用程序将允许几种生物物理方法的主要验证演示，以实时监测LH受体功能。这些方法将被纳入R01应用程序，其中包含卵巢细胞对排卵前LH脉冲和LH激增反应的信号的详细检查。此外，该项目范围有限，可能在两年内完成。美国国家老龄化研究所衰老生物学计划（BAP）对该项目的共同支持也可能是合适的。随着年龄的增长，LH脉搏的变化与AD的发展有关，因此代表了一种“不利的变化”，可能是老年人群中发生频率高的疾病发展的危险因素。

DESCRIPTION (provided by applicant): Elevations of luteinizing hormone (LH) levels with aging have been implicated in the development of Alzheimer's Disease (AD); evidence from clinical studies suggests that treatment of patients with a GnRH antagonist, Lupron, reduces LH levels, slows the progression of AD and improves cognitive function. Although there have been studies implicating LH effects on processing of amyloid-¿ in the murine brain and M17 cells, there is surprisingly little known about direct effects of LH on the nervous system. Recent studies addressing this question have used fixed concentrations of LH and ignored the fact that LH secretion, particular in women, is strongly pulsatile and that there are effects of aging on the amplitude of LH pulses. Here we propose to examine the effects of high amplitude LH pulses on M17 cells, a neuroblastoma cell line which expresses LH receptors and processes amyloid-¿ from its precursor. LH receptor pulses characteristic of young women and of post-menopausal women will be compared. We hypothesize that exposure of M17 neuroblastoma cells to LH pulses at amplitudes characteristic of those in post-menopausal women significantly increases the secretion of amyloid-¿, a protein that appears in excess in the brains of patients with AD. These studies will also develop, for the first time, strategies for imaging events associated with LH-mediated signaling in living cells during exposure to hormone. We have chosen the R03 mechanism for this application for several reasons. This project involves the "development of new research technology", a goal of the NICHD's R03 funding mechanism. Support for this R03 application will permit a proof-of-principal demonstration of several biophysical approaches to monitor LH receptor function in real time. These approaches will be incorporated into an R01 application containing a detailed examination of signaling by ovarian cells in response to pre-ovulatory LH pulses and the LH surge. In addition, this project is of limited scope and likely to be completed within two years. Shared support for this project from the Biology of Aging Program (BAP) in the National Institute of Aging might also be appropriate. Changes in LH pulsatility with aging are implicated in the development of AD and thus represent an "adverse change" that may be a risk factor for development of a disease that occurs with high frequency in an aging population.