Cell type-specific roles of calpain-2 in formation of peripheral myelinated nerves

calpain-2 在周围有髓神经形成中的细胞类型特异性作用

基本信息

批准号：
10011907
负责人：
Keiichiro Susuki
金额：
$ 7.5万
依托单位：
WRIGHT STATE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2019
资助国家：
美国
起止时间：
2019-09-15 至 2022-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10011907
关键词：
1 year old AVIL gene Action Potentials Adult Afferent Neurons Age Alleles Animal Behavior Axon Behavior Biological Assay Biology Calcium Calpain Caspase Cytoskeleton Data Demyelinating Diseases Development Disease Electron Microscopy Embryo Erinaceidae Family Functional disorder Future Gene Expression Gene Proteins Growth Immune Immunofluorescence Microscopy Injury Knock-out Knockout Mice Knowledge Length Limb structure LoxP-flanked allele Maintenance Mediating Messenger RNA Molecular Multiple Sclerosis Mus Mutant Strains Mice Myelin Myelin Sheath Myelinated nerve fiber Natural regeneration Nerve Nerve Fibers Nerve compression syndrome Nervous System Trauma Nervous system structure Neural Conduction Neuraxis Neuronal Injury Neurons Nodal Organ Patients Peripheral Peripheral Nerves Peripheral Nervous System Peripheral Nervous System Diseases Process Public Health Publishing Ranvier&apos s Nodes Reporting Research Role Rotarod Performance Test Schwann Cells Structure Testing Translational Research Western Blotting axonal degeneration base cell type conditional knockout disability disabling symptom effective therapy in vivo injury and repair innovation m-calpain mouse model mu-calpain mutant myelination nerve conduction study nervous system development novel novel therapeutics postnatal postnatal development sciatic nerve spinal nerve posterior root tool translational impact

项目摘要

Project summary/abstract Both Schwann cells and neurons are essential for the formation of myelinated nerve fibers in the peripheral nervous system (PNS). In addition to the electrical insulation of axons by myelin sheaths, Schwann cells assemble nodes of Ranvier, the excitable axonal domains required for rapid and efficient action potential propagation. Furthermore, Schwann cells actively modulate PNS degeneration and regeneration. However, the cellular and molecular mechanisms of how these structures are formed, maintained, and disrupted in disease conditions remain poorly understood. This critical gap in knowledge limits the field’s ability to manipulate the Schwann cells and neurons for treatment of PNS diseases and injuries. The overall objective of this application is to identify a critical molecular mechanism in the process of PNS myelinated nerve formation and injury. The prior studies and preliminary data provided here have identified activation of calpains, calcium-dependent intracellular cysteine proteases, and elevation of calpain-2 levels are involved in these processes. The constitutive knockout of calpain-2 in mice results in embryonic lethality before myelin is formed, further emphasizing the importance of calpain-2 in development of multiple organs including nervous system. The central hypothesis is that calpain-2 modulates formation and injury of peripheral myelinated nerves. To begin to test this hypothesis, this application will generate conditional knockout mice lacking calpain-2 in myelinating Schwann cells (Aim 1) or in sensory neurons (Aim 2). Specific aim one will test the hypothesis that Schwann cell calpain-2 mediates PNS myelination. Specific aim two will test the hypothesis that axonal calpain-2 modulates PNS node of Ranvier structures. Myelin and nodal structures in PNS, nerve conduction along PNS myelinated axons, and animal behavior will be examined during postnatal development and in adult conditional knockout and control mice. This application is conceptually innovative, in that we propose that calpain-2 is a key modulator of myelinated nerve formation in PNS. This application will generate novel calpain-2 conditional knockout mice, which will be used in future studies to determine Schwann cell-specific or neuron-specific roles of calpain-2 in PNS injury and repair. The proposed research is significant, because completion of the aims will identify calpain-2 as a potential modulator of myelinated nerve formation and remodeling in the PNS. Furthermore, future research, utilizing conditional knockout mice generated in this application, is expected to uncover cell type-specific roles of calpain-2 in PNS injuries and will substantially impact future translational research aimed at the development of novel therapies for a wide variety of PNS diseases and injuries.

项目概要/摘要雪旺细胞和神经元对于形成有髓神经纤维至关重要周围神经系统（PNS）除了髓磷脂鞘的轴突电绝缘外，雪旺氏（Schwann）。细胞组装 Ranvier 节点，这是快速有效的动作电位所需的可兴奋轴突域此外，雪旺细胞积极调节三七总皂苷的退化和再生。这些结构在疾病中如何形成、维持和破坏的细胞和分子机制人们对这些条件仍然知之甚少，这限制了该领域操纵该领域的能力。用于治疗 PNS 疾病和损伤的雪旺细胞和神经元本申请的总体目标。旨在确定PNS有髓神经形成和损伤过程中的关键分子机制。先前的研究和此处提供的初步数据已确定钙依赖性钙蛋白酶的激活细胞内半胱氨酸蛋白酶和 calpain-2 水平升高参与这些过程。小鼠中 calpain-2 的组成型敲除导致髓磷脂形成之前的胚胎致死，进一步强调 calpain-2 在包括神经系统在内的多个器官发育中的重要性。中心假设是 calpain-2 开始调节周围有髓神经的形成和损伤。检验这一假设，该应用程序将产生髓鞘形成中缺乏 calpain-2 的条件敲除小鼠施万细胞（目标 1）或感觉神经元（目标 2）。具体目标一将检验施万细胞的假设。细胞 calpain-2 介导 PNS 髓鞘形成。具体目标二将检验轴突 calpain-2 的假设。调节 Ranvier 结构的 PNS 节点和 PNS 中的髓磷脂结构，以及沿 PNS 的神经传导。有髓轴突和动物行为将在出生后发育和成年条件下进行检查该应用在概念上是创新的，因为我们提出钙蛋白酶敲除2是一种 PNS 中有髓神经形成的关键调节剂该应用将产生新型 calpain-2 条件条件。施万细胞特异性或基因敲除小鼠，将在未来的研究中用于确定施万细胞特异性或敲除特异性作用 calpain-2 在 PNS 损伤和修复中的作用拟议的研究意义重大，因为目标的完成将确定 calpain-2 是 PNS 中有髓神经形成和重塑的潜在调节剂。此外，未来的研究利用本申请中产生的条件敲除小鼠，预计将揭示 calpain-2 在 PNS 损伤中的细胞类型特异性作用，并将对未来的转化产生重大影响研究旨在开发针对多种 PNS 疾病和损伤的新疗法。