Traumatic axonal injury in the visual system: role of dual leucine zipper kinase

视觉系统外伤性轴突损伤：双亮氨酸拉链激酶的作用

• 批准号: 10153784
• 负责人: VASSILIS E. KOLIATSOS
• 金额: $ 49.43万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-04-01 至 2024-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10153784
• 关键词: Acceleration; Atrophic; Axon; Axotomy; Blindness; Blood; Brain; CRISPR/Cas technology; Cell Death; Cessation of life; Clinical Services; Clustered Regularly Interspaced Short Palindromic Repeats; Communities; Crush Injury; Data; Denervation; Diffuse; Drug Targeting; Enzymes; FDA approved; Foundations; Functional disorder; Genes; Genetic; Impairment; Incidence; Individual; Injury; Knock-out; Knockout Mice; Label; Laboratories; Lesion; Leucine Zippers; Location; LoxP-flanked allele; MAPK8 gene; Mediator of activation protein; Methods; Modeling; Molecular; Mus; Nerve Crush; Nerve Degeneration; Neuroanatomy; Neurons; Optic Nerve; Optic Nerve Injuries; Optic tract structure; Outcome; Pathway interactions; Pharmacology; Phosphotransferases; Preparation; Presynaptic Terminals; Resolution; Retinal Ganglion Cells; Rodent; Role; Rotation; Severities; Signal Pathway; Signal Transduction; Signaling Molecule; System; Testing; Therapeutic; Therapeutic Effect; Time; Tracer; Transgenic Organisms; Traumatic Brain Injury; Visual; Visual Acuity; Visual system structure; Work; axon injury; axonal degeneration; axonopathy; base; behavior measurement; brain tissue; cell injury; clinically relevant; conditional knockout; design; drug development; experimental study; genome editing; inhibitor/antagonist; injured; kinase inhibitor; mechanical force; medical attention; member; neuropathology; novel; novel therapeutics; prevent; protective effect; relating to nervous system; response; retinal ganglion cell degeneration; retinotectal; superior colliculus Corpora quadrigemina

PROJECT SUMMARY Traumatic brain injury (TBI) is a very common problem with over 2 million new cases requiring medical attention annually in the US. A neuropathology that is widely shared among various types of TBI and across spectrum of severity is diffuse or traumatic axonal injury (TAI), a form of ultra-rapid deformation and disruption of axons caused by rotational acceleration and shearing of brain tissue. In this project we use a visual model of TAI and explore the hypothesis that the DLK-JNK signaling cascade, known to be activated in simple axotomy lesions like nerve crush, triggers downstream degenerative effects of TAI in neurons projecting in the optic nerve, i.e. retinal ganglion cells (RGCs). We ask three questions, in logical order: is DLK-JNK pathway activated in visual TAI? If so, does DLK-JNK activation trigger retrograde degenerative effects in RGCs as in simple axotomy models? And does blocking of the DLK-JNK pathway prevent or treat RGC degeneration and related system impairments such as disconnection with CNS targets and loss of vision? To inflict TBI, we use the impact acceleration model of diffuse TAI with which we have consistently produced primary optic nerve injury in our laboratories. Our experimental subjects are conditional knockout mice for key members of the dual leucine zipper kinase (DLK-JNK) cascade. We also employ CRISPR strategies to disrupt the initiating kinases of the DLK-JNK cascade, DLK and LZK, and also treat wild-type injured mice with the DLK inhibitor sunitinib. Our experimental readouts include kinase activation, cell death, axonal and terminal degeneration using conventional and high-resolution (CLARITY) neuroanatomical methods, and behavioral measures of visual acuity. Besides exploring the role of key members of the DLK-JNK signaling pathway in perikaryal and axonal degeneration in visual TAI, the proposed experiments provide proof of concept for the protective or therapeutic effect of DLK/LZK blockade in TAI. The project leverages the complementary strengths of our laboratories and the design and experimental methods are supported by extensive preliminary studies. In Specific Aim 1 that serves as the foundation of the proposal, we will determine whether TAI in the visual system is associated with activation of the DLK-JNK signaling cascade in RGCs and we will identify key signaling molecules. In Specific Aim 2, we will explore whether blocking JNK and DLK/LZK signaling with knockout/genome editing strategies or pharmacological inhibition prevents or aborts RGC perikaryal and axonal degeneration in visual TAI. In Specific Aim 3, we will determine whether blocking DLK/LZK activation with knockout/genome editing strategies or pharmacological approaches prevents or aborts neural system impairments (visual disconnection and dysfunction). Taken together, these experiments examine the role of the DLK-JNK pathway in neuronal degeneration, disconnection, and dysfunction following TAI in a model CNS system and explore novel protective and therapeutic strategies for diffuse TBI.

项目摘要 创伤性脑损伤（TBI）是一个非常常见的问题，有超过200万的新病例需要医疗护理。 每年在美国引起注意。神经病理学在各种类型的TBI中广泛共享， 一系列的严重程度是弥漫性或创伤性轴索损伤（TAI），一种超快速变形和破坏的形式 由旋转加速和脑组织的剪切引起的轴突断裂。在这个项目中，我们使用了一个可视化的模型， TAI和探索的假设，DLK-JNK信号级联，已知被激活，在简单的轴突切断 损伤如神经挤压，触发TAI在投射到视神经的神经元中的下游变性效应 神经，即视网膜神经节细胞（RGC）。我们问了三个问题，按逻辑顺序：DLK-JNK通路 在视觉TAI中激活？如果是这样，DLK-JNK激活是否会触发RGC中的退行性变性效应，如 简单的轴突切断模型阻断DLK-JNK通路是否能预防或治疗RGC变性， 相关系统损伤，如与CNS靶点断开连接和视力丧失？为了造成创伤性脑损伤， 弥漫性TAI的冲击加速度模型，我们一直生产初级视神经 在我们的实验室里。我们的实验对象是条件性敲除小鼠的关键成员的双重 亮氨酸拉链激酶（DLK-JNK）级联。我们还采用CRISPR策略来破坏启动激酶， 的DLK-JNK级联，DLK和LZK，也用DLK抑制剂舒尼替尼治疗野生型损伤小鼠。 我们的实验读数包括激酶激活、细胞死亡、轴突和末端变性，使用 常规和高分辨率（HIVITY）神经解剖学方法，以及视觉行为测量 敏锐度除了探讨DLK-JNK信号通路的关键成员在核周和轴突中的作用外， 由于在视觉TAI中的变性，所提出的实验为保护性或治疗性的治疗提供了概念证明。 DLK/LZK阻断在TAI中作用。该项目利用了我们实验室的互补优势， 设计和实验方法得到了广泛的初步研究的支持。具体目标1： 作为建议的基础，我们将确定视觉系统中的TAI是否与 在RGCs中DLK-JNK信号级联的激活，我们将鉴定关键信号分子。在特定 目的2：探讨基因敲除/基因编辑技术是否能阻断JNK和DLK/LZK信号通路 或药理学抑制预防或中止视觉TAI中的RGC核周和轴突变性。在 具体目标3，我们将确定是否通过敲除/基因组编辑来阻断DLK/LZK激活 策略或药理学方法预防或中止神经系统损伤（视觉断开 功能障碍）。总之，这些实验检查了DLK-JNK通路在神经元凋亡中的作用。 在模型CNS系统中TAI后的变性、断开和功能障碍，并探索新的 弥漫性TBI的保护和治疗策略。

项目成果

Long-Term Changes in Axon Calibers after Injury: Observations on the Mouse Corticospinal Tract.

• DOI: 10.3390/ijms23137391
• 发表时间: 2022-07-02
• 期刊: International journal of molecular sciences
• 影响因子: 5.6

Protective effects of NAMPT or MAPK inhibitors and NaR on Wallerian degeneration of mammalian axons.

• DOI: 10.1016/j.nbd.2022.105808
• 发表时间: 2022-09
• 期刊: NEUROBIOLOGY OF DISEASE
• 影响因子: 6.1
• 作者: Alexandris, Athanasios S.;Ryu, Jiwon;Rajbhandari, Labchan;Harlan, Robert;McKenney, James;Wang, Yiqing;Aja, Susan;Graham, David;Venkatesan, Arun;Koliatsos, Vassilis E.
• 通讯作者: Koliatsos, Vassilis E.