Role of leucine zipper bearing kinase LZK in mammalian axon regeneration

描述(申请人提供)：由大脑和脊髓组成的成年哺乳动物中枢神经系统中轴突再生的能力有限，是脊髓损伤后功能恢复的主要障碍，目前尚无有效的治疗方法。 治疗。了解调节神经元再生轴突的内在能力的分子成分将有助于识别轴突修复的潜在治疗靶点。亮氨酸拉链蛋白激酶LZK/MAP3K13是线虫和果蝇再生反应所必需的无脊椎动物双亮氨酸拉链蛋白DLK-1/Wallenda的两个哺乳动物同源物之一，是哺乳动物轴突再生的候选调节因子。这项拟议的项目验证了LZK是哺乳动物轴突再生的神经元内在正调节因子的假设。在第一个目标中，将利用各种神经元细胞系和原代神经元在体外建立过表达或耗尽LZK对轴突延伸和再生的影响。第二个目标是通过生化和免疫组织化学方法在体外和体内检测LZK对轴突切断的依赖调节，然后确定介导LZK对轴突再生影响的下游信号效应因子。在第三个目标中，将在他莫昔芬诱导的感觉神经元特异性LZK缺失小鼠中检查轴突再生中对LZK的需求。LZK过表达促进轴突再生的能力也将在野生型小鼠中进行研究。LZK作为成年哺乳动物轴突再生调节因子的建立及其信号成分的阐明，将为脊髓损伤和某些涉及轴突损伤的神经退行性疾病的治疗提供潜在的分子基础。

DESCRIPTION (provided by applicant): The limited ability of axons in the adult mammalian central nervous system, consisting of the brain and spinal cord, to regenerate is a major obstacle to functional recovery from spinal cord injuries for which there is currently no effective treatment. Understanding the molecular components regulating neuron-intrinsic capacity to regenerate axons will facilitate the identification of potential therapeutic targets for axon repai. Leucine zipper-bearing kinase LZK/MAP3K13 is an appealing candidate regulator of mammalian axon regeneration because it is one of two mammalian homologues of the invertebrate dual leucine zipper-bearing kinase DLK-1/Wallenda required for the regenerative response in Caenorhabditis elegans and Drosophila melanogaster. The proposed project tests the hypothesis that LZK is a neuron- intrinsic positive regulator of mammalian axon regeneration. In the first aim, the effect of overexpressing or depleting LZK on neurite extension and regeneration will be established in vitro using various neuronal cell lines and primary neurons. In the second aim, axotomy- dependent regulation of LZK will be examined in vitro and in vivo by biochemical and immunohistochemical approaches, followed by identification of the downstream signaling effectors mediating the effect of LZK on axon regeneration. In the third aim, the requirement for LZK in axon regeneration will be examined in tamoxifen-inducible and sensory neuron-specific LZK null mice. The ability of LZK overexpression to promote axon regeneration will also be investigated in wildtype mice. Establishment of LZK as a regulator of axon regeneration in adult mammals and elucidation of its signaling components will provide the molecular basis for potential development of therapeutic interventions for spinal cord injuries and certain neurodegenerative diseases involving axonal damage.