Regenerative and degenerative responses to axonal injury

项目摘要/摘要： 轴突在大脑和身体的很远的距离上形成神经元之间的连接，因此很容易受到 损伤和压力。该项目研究了进化上保守的应激反应途径，该途径成为 在轴突损伤和应激的多种情况下被激活。这条小路由双亮氨酸拉链控制 DLK在果蝇中被称为Wallenda(WND)，参与神经元的结构可塑性机制 使电路能够适应轴突损伤。这些反应包括轴突再生，神经元死亡， 而且，这个项目中新发现的突触丢失。这个项目的长期目标是：(1)了解 导致DLK信号激活的机制，以及(2)了解 受DLK监管。父母的资助在小鼠和果蝇中使用了DLK/WND的遗传操作，具有 关注体内的表型。然而，要理解DLK的调节机制(S)(一个支配性的 目标1的目标)以及它如何调节不同的结果(目标2的核心目标)，我们试图开发一种体外 适用于生化、药理学和遗传学方法的DLK研究范式。AS 在2022年4月的RRPR中进行了讨论，我们现在已经建立了可靠的方法来在 原代皮质神经元培养。新的方法为推进这两个目标提供了新的途径。 原拨款的一部分。药理学实验被用来探索DLK信号的分子介体 激活(目标1)，以及细胞成像和生化实验来探索DLK是如何激活的 可以在文化中调解不同的结果(目标2)。这一努力是与萨米人合作进行的 密歇根大学医学院的Barmada博士说。副刊申请寻求招聘 Yelitzza Aguar，他在这个项目上的毕业后工作(在密歇根大学的Barmada实验室)将研究 DLK介导过量谷氨酸暴露的皮质神经元培养中神经元死亡的机制。 拟议的补充工作将通过以下方式推进增加生物医学研究多样性的使命 支持来自弱势背景的有前途的学生的指导和职业发展 在生物医学研究方面。

Project Summary/Abstract: Axons form connections between neurons over great distances in the brain and body, hence are vulnerable to damage and stress. This project studies an evolutionarily conserved stress response pathway that becomes activated in multiple scenarios of axonal damage and stress. The pathway, governed by the dileucine zipper kinase DLK, known as Wallenda (Wnd) in Drosophila, engages structural plasticity mechanisms in neurons that allow circuits to adapt to axon damage. These responses include axonal regeneration, neuronal death, and, newly discovered in this project, synapse loss. The long-term goals of this project are (1) to understand the mechanisms that lead to DLK signaling activation, and (2) to understand the cellular pathways that are regulated by DLK. The parent grant uses genetic manipulations of DLK/Wnd in mice and Drosophila, with a focus on in vivo phenotypes. However, to understand the mechanism(s) of DLK’s regulation (an overarching goal of Aim 1) and how it mediates diverse outcomes (a central goal of Aim 2), we sought to develop an in vitro paradigm for studying DLK that is amenable to biochemical, pharmacological and genetic approaches. As discussed in the April 2022 RRPR, we have now established robust methods to activate DLK signaling within primary cortical neuron cultures. The new methods provide new inroads to advancing the advancing both aims of the original grant. Pharmacology experiments are used to probe the molecular mediators of DLK signaling activation (Aim 1), and cellular imaging and biochemical experiments are used to probe how DLK activation can mediate distinct outcomes in the cultures (Aim 2). This endeavor is carried out in collaboration with Sami Barmada at the University of Michigan (UM) School of Medicine. The supplement application seeks to hire Yelitzza Aguilar, whose postbaccalaureate work on this project (in the Barmada lab at UM) will study the mechanism by which DLK mediates neuronal death in cortical neuron cultures exposed to excess glutamate. The proposed supplemental work will advance the mission of increasing diversity in biomedical research by supporting the mentorship and career development of a promising student from a disadvantaged background in biomedical research.