Activity-dependent regulation of the choroid plexus-cerebrospinal fluid stem cell niche

脉络丛-脑脊液干细胞生态位的活动依赖性调节

• 批准号: 9980554
• 负责人: MARIA LEHTINEN
• 金额: $ 65.57万
• 依托单位: BOSTON CHILDREN'S HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-05-15 至 2025-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/9980554
• 关键词: Address; Affect; Agonist; Apical; Axon; Brain; Brain Stem; Calcium; Cells; Cerebral cortex; Cerebrospinal Fluid; Cerebrum; Choroid Plexus Epithelium; Couples; Cues; Data; Development; Diffusion; Disease; Embryo; Embryonic Development; Environment; Epithelial; Epithelial Cells; Epithelium; Fetal health; Future; G-Protein-Coupled Receptors; GTP-Binding Protein alpha Subunits, Gs; Gene Expression; Gene Proteins; Genetic; Genetic Transcription; Growth; Health; Image; Immediate-Early Genes; In Vitro; Intraperitoneal Injections; Investigation; Ligands; Mediating; Methods; Modernization; Molecular; Monitor; Mus; Nature; Neurologic; Neurons; Penetrance; Peripheral; Phenotype; Placenta; Process; Production; Protein Secretion; Receptor Activation; Receptor Signaling; Regulation; Salivary Glands; Serotonin; Signal Pathway; Signal Transduction; Source; Stimulus; Structure of choroid plexus; Surface; Testing; brain tissue; direct application; experimental study; fetal; gene induction; in vivo; in vivo calcium imaging; intraperitoneal; loss of function; nerve stem cell; neurosteroids; novel; postnatal; receptor; response; stem cell niche; tool; transcriptome; transcriptome sequencing; transcriptomics; vesicular release

PROJECT SUMMARY / ABSTRACT Building the cerebral cortex requires the spatial and temporal orchestration of molecular signals across neural progenitor cells. Each of these cells is bathed in cerebrospinal fluid (CSF), a medium rich in health- and growth- promoting factors whose composition changes profoundly across days during brain development. The choroid plexus (ChP) is likely to strongly contribute to this dynamic developmental regulation of CSF composition, but the underlying mechanisms are not understood. Here, we will use a suite of modern tools to test the hypothesis that elevations in calcium concentration in embryonic ChP epithelial cells in response to extrinsic cues is critical for regulating synthesis and secretion of signaling factors into the CSF. Calcium activity regulates transcription and secretion in diverse cells ranging from neurons to salivary gland epithelia. We identified receptors expressed in ChP epithelial cells that mediate calcium entry into the cell, such as the TRPM3 receptor, or that drive calcium release from internal stores, such as the 5HT2C receptor (Htr2c) for serotonin (5- HT, 5-hydroxytryptamine). Our preliminary data suggest that 5-HT regulates embryonic ChP calcium activity, transcription, and vesicle release, and that intact signaling via the 5HT2C receptor in ChP is essential for normal cerebral cortical development. Further, maternal delivery of a selective agonist for the 5HT2C receptor triggers rapid, robust immediate early gene expression in embryonic ChP. Thus, we propose that ChP calcium activity triggered by signals that activate the 5HT2C receptor (and other receptors such as TRPM3) regulates ChP transcription and secretion of signaling factors into the CSF and controls body-brain and maternal-fetal interactions, thereby tightly orchestrating cerebral cortical development. To test this, we will first investigate the effects of 5HT2C and TRPM3 receptor activation by direct application of ligand to the apical surface of epithelial cells during calcium imaging in ChP explants (Aim 1a) and by stimulation of the basal surface following intraperitoneal (IP) delivery of ligands to the maternal dam during in vivo two- photon calcium imaging of attached embryos (Aim 1b). We then assess the transcriptomic impact of such stimulation (Aim 1c), and test whether embryonic ChP calcium activity via activation of 5HT2C receptors and other receptors triggers vesicle release and protein secretion in vitro (Aim 2a) and in vivo (Aim 2b). We will also analyze the effects of disruption of ChP receptor signaling on cortical development (Aim 3a). Disrupted CSF volume, composition, and ventricle formation are common to many neurological conditions. Perturbations in maternal-fetal health can disrupt brain development, in part via dysregulation of serotonergic and other signaling pathways. Our findings provide a novel platform for elucidating the mechanisms underlying dysregulation of brain development by environmental perturbations, thereby providing a conceptual and technical roadmap for future studies on how activity in ChP epithelial cells influences gene expression and protein secretion, with consequences for many neurodevelopmental diseases.

项目概要/摘要 构建大脑皮层需要跨神经元的分子信号的空间和时间编排 祖细胞。这些细胞中的每一个都沐浴在脑脊液（CSF）中，这是一种富含健康和生长物质的介质 在大脑发育过程中，促进其成分在几天内发生深刻变化的因素。脉络膜 神经丛（ChP）可能对脑脊液成分的这种动态发育调节有很大贡献，但是 根本机制尚不清楚。在这里，我们将使用一套现代工具来测试 假设胚胎 ChP 上皮细胞中的钙浓度升高是对 外在信号对于调节信号因子合成和分泌到脑脊液中至关重要。钙 活性调节从神经元到唾液腺上皮细胞等多种细胞的转录和分泌。我们 鉴定出在 ChP 上皮细胞中表达的介导钙进入细胞的受体，例如 TRPM3 受体，或驱动内部储存的钙释放，例如血清素的 5HT2C 受体 (Htr2c)（5- HT，5-羟色胺）。我们的初步数据表明 5-HT 调节胚胎 ChP 钙 活性、转录和囊泡释放，并且 ChP 中通过 5HT2C 受体的完整信号传导是 对于大脑皮层的正常发育至关重要。此外，母体递送选择性激动剂 5HT2C 受体触发胚胎 ChP 中快速、稳健的早期基因表达。因此，我们建议 ChP 钙活性由激活 5HT2C 受体（以及其他受体，例如 TRPM3）调节 ChP 转录和信号因子分泌到 CSF 中并控制 身体-大脑和母体-胎儿的相互作用，从而紧密协调大脑皮层的发育。 为了测试这一点，我们将首先通过直接应用来研究 5HT2C 和 TRPM3 受体激活的影响 ChP 外植体钙成像过程中（目标 1a）和刺激作用下上皮细胞顶端表面的配体 在体内两次腹膜内（IP）将配体递送至母体后基底表面的 附着胚胎的光子钙成像（目标 1b）。然后我们评估此类的转录组影响 刺激（目标 1c），并测试胚胎 ChP 钙活性是否通过激活 5HT2C 受体和 其他受体在体外（目标 2a）和体内（目标 2b）触发囊泡释放和蛋白质分泌。我们也会 分析 ChP 受体信号传导破坏对皮质发育的影响（目标 3a）。脑脊液受损 体积、组成和心室形成对于许多神经系统疾病来说是常见的。扰动 母婴健康可能会扰乱大脑发育，部分原因是血清素能和其他信号传导失调 途径。我们的研究结果为阐明大脑失调的机制提供了一个新的平台 环境扰动的发展，从而为未来提供概念和技术路线图 研究 ChP 上皮细胞的活性如何影响基因表达和蛋白质分泌， 许多神经发育疾病的后果。