Hypothalamic Orexin Role in Menopause-Associated Hot Flashes and Mood/Sleep Disru

描述(申请人提供)：目前我在以下方面接受了广泛的培训：1)硕士论文期间女性性激素和行为的神经内分泌学；2)博士论文期间的应激反应的神经内分泌学和功能神经解剖学；3)博士后培训期间的翻译动物建模。这项培训集中于整个动物的生理和行为，结合使用微透析的体内神经化学措施；通过立体定向传递药物和轨迹跟踪化合物；以及使用免疫组织化学进行体外脑功能成像，以检测即时早期基因蛋白。2008年和2010年，我先后被提升为研究助理教授和精神病学系助理教授。在此期间，我发表了一篇第一作者《自然医学》的文章，其中的主要发现是，在公认的恐慌症大鼠模型中，下丘脑食欲素系统在恐慌症易感性中扮演着关键角色，而且在恐慌症患者中，中枢食欲素水平升高。我继续确定其他病理是否与过度活跃的食欲素系统有关。正是在这里，我在临床前研究中注意到雌激素抑制食欲素活性，最近的一项临床研究表明，绝经期间雌激素的急剧丧失导致中枢食欲素水平增加300%，而雌激素替代后这一情况正好相反。这一证据，再加上食欲素在体温调节中的已知作用，以及食欲素系统位于下丘脑富含两种雌激素受体的区域，导致了我目前的假设：“食欲素系统在更年期相关症状(如潮热、情绪/睡眠紊乱)中发挥关键作用。”大约70%的接近更年期的女性会受到潮热等不良更年期症状的影响，北美更年期协会估计，每天有超过6000名美国女性进入更年期。此外，年龄在50-之间的妇女中，有63%目前有工作(美国人口普查局，2003年)。因此，不良更年期症状通过损失工作日和医疗服务的直接保健费用对工作场所产生重大的财务影响。这笔K01培训补助金代表了我职业生涯中一个重要但合乎逻辑的重新定位，需要印第安纳大学专家在以下方面提供额外的指导和培训：1)Daniel Rusyniak医学博士在啮齿动物方面的研究；2)Kathryn Jones博士在性激素神经内分泌学方面的研究；3)人类受试者中与更年期相关的“潮热”，以及由Janet Carpenter，博士，RN，FAAN教授的更年期课程；以及4)翻译研究方法和动物模型，由Anantha Shekhar，医学博士/博士教授。我的培训还将包括Todd Skaar博士为Aim 1进行的药理学培训；IUSM的William Truitt博士和Kenneth Cornetta MD为Aim 2和3进行的分子生物学课程和培训；以及IUSM的Robert Bies博士在Aim 3b进行的昼夜节律分析培训。在Rusyniak博士和Carpenter博士的初步指导下，我获得了内部资助的CTSI项目发展赠款和2011年翻译研究领域的KL-2 CTSI青年研究人员基础科学奖，以获得这笔赠款的初步数据。本文概述的目标和研究将有助于从‘Roadmap’K奖过渡到‘Roadmap’R奖。我曾在2011年的美国神经精神药理学学院和2012年的翻译科学会议上提交了初步结果，在那里我分别被选为“数据闪电战”会议的成员；并获得了学者摘要奖。我还在准备一份关于我们的“潮热”脆弱性新模型的手稿。本文提出的研究具有创新性，原因如下：1)据我们所知，这是首次尝试确定增食欲素的作用 有不良的更年期症状。在PubMed上搜索“食欲素”和“潮热”，这是更年期的主要症状，截至2013年3月没有任何结果；2)这项拟议的研究基于有关食欲素的雌激素调节和受体生理学的临床前信息，食欲素在睡眠唤醒周期中的作用，以及我们最近的临床前和临床数据，将过度活跃的食欲素系统与焦虑和体温失调联系起来；3)我们将进行动物实验，以阐明食欲素诱导更年期症状的潜在机制，据我们所知，这在以前还没有报道；4)我开发了新的动物模型来检验我的假设；5)我将应用药理学、急性基因和慢性慢病毒siRNA基因沉默技术来了解其机制；6)我将阐明调节潮热的神经学机制，重点是下丘脑的食欲素系统；以及7)我将进行机制研究，从而找到一种翻译临床方案，发现一种食欲素受体拮抗剂的新用途，该药物已提交FDA批准用于治疗失眠。我最近接受了IUSM解剖学和细胞生物学系的终身教职助理教授的职位。我的实验室(湿实验室、手术区和生理/行为室)与特鲁伊特博士隔着大厅，与鲁西尼亚克博士隔着一层楼，与我的其他导师步行即可到达，这使这里成为一个理想的指导和协作环境。因此，这笔培训补助金的最终目标是帮助我成为一名独立的调查员，对雌激素的急剧丧失如何导致体温调节紊乱有广泛的了解。这将使我能够为我们对导致潮热的神经和神经化学机制的知识做出重大贡献，并确定潜在的非激素治疗靶点。

DESCRIPTION (provided by applicant): Currently I have had extensive training in: 1) neuroendocrinology of female sex hormones and behavior during my Masters with Thesis; 2) neuroendocrinology and functional neuroanatomy of stress responses during my PhD dissertation; and 3) translational animal modeling during my postdoctoral training. This training was collectively focused on whole animal physiology and behavior, combined with in vivo neurochemistry measures using microdialysis; stereotaxic delivery of pharmacological and tract tracing compounds, and ex vivo functional brain imaging using immunohistochemistry to detect immediate early gene proteins. In 2008 and 2010, I was respectively promoted to Research Assistant Professor, and then to Assistant Professor in the Department of Psychiatry. During this time I published a 1st author Nature Medicine article, where the main discovery was that a hypothalamic orexin system plays a critical role panic vulnerability in an accepted rat model of panic disorder and that central orexin levels are elevated in patients with panic disorder. I proceeded to determine if other pathologies were associated with a hyperactive orexin system. It was here that I noted in preclinical studies that estrogens suppress orexin activity and that ina recent clinical study dramatic loss of estrogen during menopause leads to a 300% increase in central levels of orexin, which was reversed with estrogen replacement. This evidence, combined with orexin's known role in thermoregulation, and that the orexin system is located in a hypothalamic area enriched in both estrogen receptors, led to my current hypothesis that "the orexin system plays a critical role in menopause-related symptoms such as hot flashes, and mood/sleep disruption". Adverse menopausal symptoms such as hot flashes affect about 70% of women approaching menopause and The North American Menopause Society posits that over 6,000 American women reach menopause daily. In addition, 63% of women ages 50-64 years are currently employed (U.S. Bureau of the Census, 2003). Thus, adverse menopausal symptoms have a significant financial impact in the workplace through lost work days and direct health care costs for medical services. This K01 training grant represents a significant, but logical, redirection in my career that requires additional mentoring and training by experts at IU in: 1) rodent studies in thermoregulation by Daniel Rusyniak MD; 2) sex hormone neuroendocrinology by Kathryn Jones PhD; 3) menopause-related "hot flashes" in human subjects and a Menopause course taught by Janet Carpenter, PhD, RN, FAAN; and 4) translational research approaches and animal modeling by Anantha Shekhar, MD/PhD. My training will also involve pharmacology training by Todd Skaar PhD for aim 1; molecular biology coursework and training by William Truitt, PhD, and Kenneth Cornetta MD at IUSM for aims 2 and 3; and training in circadian analyses by Robert Bies PhD at IUSM in aim 3b. Under the initial mentorship of Drs. Rusyniak and Carpenter, I have obtained an internally funded CTSI project development grant and a KL-2 CTSI Young Investigator Basic Science Award in Translational Research in 2011 to gain preliminary data for this grant. The aims and studies outlined here will aid in the transition from a 'Roadmap' K award to 'Roadmap' R awards. I have presented preliminary results at the American College of Neuropsychopharmacology in 2011 and at the Translational Science meeting in 2012, where I was respectively selected for the "Data Blitz" session; and won a Scholar's Abstract Award. I am also preparing a manuscript on our novel models of "hot flash" vulnerability. The proposed research outlined here is innovative for the following reasons: 1) to our knowledge this is the first attempt to determine orexin's role in adverse menopausal symptoms. A PubMed search for "orexin" and "hot flash" which is the primary menopause symptom yields no results as of March 2013; 2) this proposed research is based on preclinical information about estrogen regulation of orexin and receptor physiology, orexin's role in sleep wakes cycles, and our recent preclinical and clinical data linking a hyperactive orexin system to anxiety and temperature dysregulation; 3) we will conduct animal studies to elucidate the mechanisms underlying orexin induction of menopausal symptoms, which to our knowledge, has not been previously reported; 4) I have developed novel animal models of hot flash vulnerability to test my hypotheses; 5) I will apply pharmacology, acute gene and chronic lentiviral siRNA gene silencing techniques to understand the mechanism; 6) I will elucidate the neurologic mechanisms that regulate hot flashes with emphasis on the hypothalamic orexin system; and 7) I will provide mechanistic studies that will lead to a translational clinical protocol finding a novel use of an orexin receptor antagonist submitted for FDA approval for insomnia. I recently accepted a tenure track Assistant Professor position in the Department of Anatomy & Cell Biology at IUSM. My laboratory (a wetlab, surgical area and physiology/behavior room) is across the hall from Dr. Truitt and one floor up from Dr. Rusyniak, and within walking distance of my other mentors, making this an ideal mentoring and collaborative setting. Therefore, it is the ultimate goal of this training grant to help me become an independent investigator with an extensive understanding of how dramatic loss of estrogens lead to disrupted thermoregulation. This will allow me to make significant contributions to our knowledge of the neural and neurochemical mechanisms that lead to hot flashes and to identify potential novel nonhormonal targets for treatment.