Single cell transcriptomics of nerves that lack Remak bundles

缺乏 Remak 束的神经的单细胞转录组学

• 批准号: 10649087
• 负责人: Lawrence S Kirschner
• 金额: $ 7.88万
• 依托单位: OHIO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-02-15 至 2025-01-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10649087
• 关键词: Ablation; Abnormal Cell; Address; Adopted; Affect; Alleles; Animals; Applications Grants; Atrial myxoma with lentigines; Axon; Benign; Biological Models; Biology; C Fiber; Cell Communication; Cell Proliferation; Cell physiology; Cells; Charcot-Marie-Tooth Disease; Cyclic AMP-Dependent Protein Kinases; Data; Defect; Development; Disease; Embryonic Development; Environment; Esthesia; Exhibits; Family; Fiber; Functional disorder; Future; Human; Individual; Inherited; Knowledge; Laboratories; Location; Mediating; Modeling; Molecular; Monomeric GTP-Binding Proteins; Morphology; Motor; Mus; Myelin; Myelin Sheath; NF1 gene; Nerve; Neural Conduction; Neural Crest Cell; Neurilemmoma; Neurofibromatoses; Neurofibromin 2; Neurons; Nociception; Outcome; Pain; Pathway interactions; Patients; Peripheral; Peripheral Nervous System; Peripheral Nervous System Malignant Neoplasms; Phenotype; Physiological; Pilot Projects; Play; Population; Process; Proliferating; Proprioception; Proteins; Role; Schwann Cells; Sensory; Signal Pathway; Signal Transduction; Signaling Molecule; Structure; Supporting Cell; Symptoms; Syndrome; Touch sensation; Transcript; Work; afferent nerve; cell growth; cell type; improved; in vivo; mouse model; mutant; neoplastic cell; nerve damage; pain perception; protein activation; response; rho; single cell analysis; single-cell RNA sequencing; transcriptome; transcriptomics; transmission process; tumor; tumorigenesis

PROJECT ABSTRACT Schwann cells (SCs) are neural crest derived cells whose primary function is the support and protection of neurons in the peripheral nervous system. SCs can be divided into two subtypes: myelinating and non- myelinating. Myelinating SCs form 1:1 relationships with neurons and ensheath them in myelin to provide rapid conduction of nerve impulses, such as those required for transduction of proprioception and touch. In contrast, non-myelinating SCs typically bundle multiple axons into nerve structures known as Remak bundles, which support the cells but do not speed transmissions. Individuals with dysfunction of SCs exhibit a variety of phenotypes which may include decreased sensation, weakness, and pain, and these diseases are among the most common inherited conditions in humans. In addition, SCs are also the cell type targeted for tumorigenesis in the Neurofibromatosis syndromes (NF1 and NF2) which ae associated with benign and malignant tumors of the peripheral nerves and other locations. Rac1 is a small GTPase protein of the Rho family, and it has been shown to essential for tumorigenesis in both NF1- and NF2-associated tumors, as well as other forms of inherited Schwann cell tumors (e.g., Carney Complex). Recently, analyses of inherited SC dysfunctional syndromes have also shown dysregulation of Rac1. To investigate the role of Rac1 signaling in SC function and tumorigenesis, my laboratory has generated a mouse model carrying a conditionally active allele of Rac1 and performed preliminary characterization of the effects of activation Rac1 at various stages of SC development. We observe that activation of Rac1 in early embryogenesis enhanced cell proliferation and affects the ability of non- myelinating SCs to form normal Remak bundles, which are completely absent from nerves with Rac1 activated in early embryogenesis. In this R03 application, we hypothesize that Rac1 activation leads to aberrant differentiation specifically in non-myelinating SCs without affecting the trajectory of myelinating SCs. Initial characterization of this defect through this pilot grant application will lead to future studies with important implications for nociception and for tumorigenesis. To address this hypothesis, we propose the single Specific Aim to assess the differential effects of activation of Rac1 on the transcriptomes of myelinating and non-myelinating Schwann cells. As a first step, will compare the transcriptomes of WT SCs to the abnormal SCs in mice with SC-targeted early activation of Rac1. Secondly, we will expand the analysis to include mice with later activation of Rac1, as these animals appear to have morphologically and functional normal SCs. Thirdly, we will validate these data by analyzing specific transcripts and proteins to verify the transcriptomic changes. If successful, these studies will begin to elucidate the important molecular functions of Rac1 in mediating the differentiation, physiologic function, and tumor implications of Schwann cells in vivo, with implications both for understanding and treating pain, and for understanding SC tumorigenesis such as in NF.

项目摘要 Schwann细胞（SC）是神经rest衍生的细胞，其主要功能是支持和保护 周围神经系统中的神经元。 SC可以分为两个亚型：髓鞘和非 - 髓鞘。髓鞘SCS表格1：1与神经元的关系，并在髓鞘中启动它们以提供快速 传导神经冲动，例如转导前置和触摸所需的神经冲动。相比之下， 非层化SC通常将多个轴突束成神经结构，称为Remak束，该轴突 支持细胞，但不会加快传输速度。 SCS功能障碍的个体表现出多种 可能包括降低感觉，无力和疼痛的表型，这些疾病是 人类最常见的遗传条件。此外，SC也是针对肿瘤发生的细胞类型 在神经纤维瘤病综合征（NF1和NF2）中，AE与良性和恶性肿瘤有关 周围神经和其他位置。 Rac1是Rho家族的小GTPase蛋白，它一直是 在NF1和NF2相关的肿瘤以及其他形式的遗传性肿瘤中表现出必不可少的 Schwann细胞肿瘤（例如Carney Complex）。最近，对遗传的SC功能失调综合征的分析具有 还显示Rac1的失调。为了研究Rac1信号在SC功能和肿瘤发生中的作用， 我的实验室已经产生了一个携带Rac1有条件活性等位基因的鼠标模型 激活Rac1在SC开发的各个阶段的效果的初步表征。我们观察到 Rac1在早期胚胎发生中的激活增强了细胞的增殖，并影响了非 - 髓鞘SC形成正常的remak束，rac1激活的神经完全不存在 在早期的胚胎发生中。在此R03应用中，我们假设Rac1激活导致异常 在非层状SC中特别分化而不影响髓鞘SC的轨迹。最初的 通过此试点赠款的申请表征此缺陷将导致未来的研究 对伤害感受和肿瘤发生的影响。 为了解决这一假设，我们提出了一个单一的特定目的，以评估 Rac1激活在髓鞘和非层状雪旺细胞的转录组上。首先 步骤，将比较WT SC的转录组与SC靶向的小鼠异常SC Rac1的激活。其次，我们将扩展分析，以包括随后激活Rac1的小鼠，因为 动物似乎具有形态和功能正常的SC。第三，我们将通过 分析特定的转录本和蛋白质以验证转录组的变化。 如果成功，这些研究将开始阐明Rac1的重要分子功能 雪旺细胞在体内的分化，生理功能和肿瘤的影响，两者都对 理解和治疗疼痛，并了解诸如NF之类的SC肿瘤发生。