Regulation of mammalian brain development by p21-activated kinase signaling pathways

p21 激活激酶信号通路对哺乳动物大脑发育的调节

• 批准号: RGPIN-2017-06295
• 负责人: Jia, Zhengping
• 金额: $ 2.91万
• 依托单位: University of Toronto
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=654640
• 关键词: Regulation; mammalian; brain; development; p21

Title: Regulation of mammalian brain development by p21-activated kinase signaling pathways******This application is a renewal of my current NSERC discovery grant (RGPIN341498, 2012-2017).******The long-term goal of my research program is to understand the fundamental mechanisms that govern brain development and function. To this end, we have identified a number of molecules that are important for neuronal proliferation, survival, migration, morphogenesis and maturation, a series of highly regulated processes critical for normal brain growth, neural circuit formation and function. With particular relevance to this application and with the funding of my current NSERC discovery grant (2012-17), we have demonstrated that knockout (KO) mice lacking the p21-activated kinases (PAKs), a family of protein kinases known to be important for cytoskeletal reorganization, are altered in brain size, cortical volume, neuronal progenitor cell division and migration. Significantly, these KO mice are defective in the activity of LIM-kinase 1 (LIMK1) and the actin-binding protein cofilin, both of which are key targets of PAKs important for actin regulation. Furthermore, we discovered that PAKs can exert effects on the endocannabinoid (eCB) system, an emerging player in various aspects of embryonic brain development. These results lead to a hypothesis that PAKs regulate cortical development via coordinating actin reorganization and eCB signaling. To address this hypothesis, we will use multiple techniques, including mouse genetics, immunohistochemistry, imaging, biochemical assays and electrophysiological recordings to achieve three specific aims: ******Aim 1. To determine the relative contribution of PAK1 and 3 in neuronal proliferation and migration by labeling and tracking neural progenitor cells in various PAK KO mice. ******Aim 2. To determine the role of PAK1 and 3 in early postnatal neuronal morphogenesis and synaptic maturation by analyzing neuronal and synaptic morphology. ******Aim 3. To elucidate the molecular mechanisms underlying PAK1/3 actions by investigating the role of LIMK1/cofilin and eCB signaling.******The results from this application will reveal the in vivo function and underlying mechanisms by which PAK signaling regulates cortical and neuronal development. This will in turn contribute to my long-term goal to understand the fundamental process governing brain development and function. Since both cortical malformations and PAKs are closely associated with many neurological and mental disorders, this proposal will also provide new insight into the pathogenesis and treatment of these diseases. ********

标题：p21 激活激酶信号通路对哺乳动物大脑发育的调节******此申请是我当前 NSERC 发现资助（RGPIN341498，2012-2017）的更新。******我的研究计划的长期目标是了解控制大脑发育和功能的基本机制。为此，我们鉴定了许多对神经元增殖、存活、迁移、形态发生和成熟很重要的分子，这些对正常大脑生长、神经回路形成和功能至关重要的一系列高度调控的过程。与本申请特别相关，并在我目前的 NSERC 发现资助 (2012-17) 的资助下，我们证明了缺乏 p21 激活激酶 (PAK)（已知对细胞骨架重组重要的蛋白激酶家族）的基因敲除 (KO) 小鼠的大脑大小、皮质体积、神经元祖细胞分裂和迁移发生了改变。值得注意的是，这些 KO 小鼠的 LIM 激酶 1 (LIMK1) 和肌动蛋白结合蛋白丝切蛋白 (cofilin) 活性存在缺陷，这两者都是对肌动蛋白调节至关重要的 PAK 的关键靶标。此外，我们发现 PAK 可以对内源性大麻素 (eCB) 系统产生影响，该系统是胚胎大脑发育各个方面的新兴参与者。这些结果得出这样一个假设：PAK 通过协调肌动蛋白重组和 eCB 信号传导来调节皮质发育。为了解决这一假设，我们将使用多种技术，包括小鼠遗传学、免疫组织化学、成像、生化测定和电生理记录来实现三个具体目标： ******目标 1. 通过标记和跟踪各种 PAK KO 小鼠的神经祖细胞来确定 PAK1 和 3 在神经元增殖和迁移中的相对贡献。 ******目标 2. 通过分析神经元和突触形态来确定 PAK1 和 3 在出生后早期神经元形态发生和突触成熟中的作用。 ******目标 3. 通过研究 LIMK1/cofilin 和 eCB 信号传导的作用，阐明 PAK1/3 作用的分子机制。********本申请的结果将揭示 PAK 信号传导调节皮质和神经元发育的体内功能和潜在机制。这反过来将有助于我了解控制大脑发育和功能的基本过程的长期目标。由于皮质畸形和 PAK 都与许多神经和精神疾病密切相关，该提议也将为这些疾病的发病机制和治疗提供新的见解。 ******