Regulation of Neurogenesis and Behavior by GSK-3

描述(申请人提供)：双相情感障碍(BD)是一种衰弱的情绪障碍，影响1-2%的人口。锂对BD非常有效，但其治疗反应的分子机制尚不清楚。确定成人大脑中锂的细胞和分子靶点对于了解导致这种复杂疾病的因素至关重要。我们提出的假设是，锂通过抑制糖原合成酶激酶-3(GSK-3)而作用于哺乳动物的行为和情绪障碍，GSK-3是多个信号通路的中央调节因子。这项工作的目标是确定细胞和分子对GSK-3抑制的反应与BD的治疗反应之间的关系，长期目标是了解情感障碍的分子基础，并发现BD和其他情感障碍的新治疗靶点。这项建议描述了实验，以确定信号机制，以解释锂对神经干细胞稳态和行为的影响。我们的工作假设是，GSK-3通过与Wnt信号和氧气感受通路相互作用来调节行为和神经发生。此外，我们假设GSK-3受正反馈电路的高度调控，可以针对情感性障碍开发新的治疗策略。在目标1中，我们将测试Wnt信号是否对于锂在神经发生或行为中的作用是必需的。我们还将使用一种针对成年海马区NSPC的遗传策略来测试对锂的行为反应是否需要神经发生。目的2探讨氧感觉和Wnt通路之间的新联系，Wnt通路是GSK-3的主要靶点，也是神经发生的调节因子。我们将探讨缺氧诱导因子1(HIF-1)在神经发生和锂敏感行为调节中的作用，并探讨HIF-1靶基因在锂反应中的作用。在目标3中，我们将探索锂增强GSK-3抑制的新机制，并研究干扰GSK-3调节电路的方法，作为治疗BD和其他情感性障碍的潜在新治疗靶点。这些研究应该能更好地了解BD的分子和细胞机制以及对治疗的反应，并应该导致治疗这种常见的和破坏性的情感障碍的新方法。

DESCRIPTION (provided by applicant): Bipolar disorder (BD) is a debilitating mood disorder that affects 1-2% of the population. Lithium is highly effective in BD, but the molecular mechanism that underlies the therapeutic response is unknown. Defining the cellular and molecular targets of lithium in the adult brain will be crucial to understanding the factors that contribute to this complex disorder. We have advanced the hypothesis that lithium acts on mammalian behavior and mood disorders through inhibition of glycogen synthase kinase-3 (GSK-3), a central regulator of multiple signaling pathways. The goals of the work proposed here are to establish how cellular and molecular responses to GSK-3 inhibition relate to the therapeutic response in BD, with a long-term goal to understand the molecular basis of affective disorders and to discover new therapeutic targets in BD and other affective disorders. This proposal describes experiments to define the signaling mechanisms that account for the effects of lithium on neural stem cell homeostasis and behavior. Our working hypothesis is that GSK-3 modulates both behavior and neurogenesis through interaction with Wnt signaling and oxygen sensing pathways. In addition, we hypothesize that GSK-3 is highly regulated by positive feedback circuits that can be targeted for the development of new therapeutic strategies in affective disorders. In aim 1, we will test whether Wnt signaling is required for the effects of lithium in either neurogenesis or behavior. We will also test whether neurogenesis is required for behavioral responses to lithium using a genetic strategy to target NSPCs in the adult hippocampus. Aim 2 addresses a new connection between oxygen sensing and the Wnt pathway, a major target of GSK-3 and a regulator of neurogenesis. We will explore the role of hypoxia inducible factor 1 (HIF-1) in the regulation of neurogenesis and lithium-sensitive behaviors and investigate the role of HIF-1 target genes in the response to lithium. In aim 3 we will explore a novel mechanism for the enhancement of GSK-3 inhibition by lithium and investigate approaches to perturb GSK-3 regulatory circuits as potentially new therapeutic targets in the treatment of BD and other affective disorders. These studies should provide a better understanding of the molecular and cellular mechanisms that underlie BD and the response to therapy and should lead to new approaches to the treatment of this common and devastating affective disorder.