Regulation of Schwann Cell Mitochondria Homeostasis in Painful Peripheral Neuropathy

项目摘要 周围神经病变具有异质性病因，并且可以由创伤性、代谢性和神经性疾病引起。 化疗引起的事件。神经性疼痛是周围神经病的主要症状， 以自发性疼痛、烧灼感和感觉异常为特征。它往往与毁灭性的损失有关， 生活质量目前，治疗方法有限，给患者带来副作用和成瘾的负担。识别 疼痛治疗的新策略解决了大量未满足的医疗需求。研究的机制 疼痛性周围神经病变（PPN）主要集中在感觉神经元，然而，周围神经胶质细胞，雪旺氏细胞， 神经干细胞（SC）作为一种重要的功能单位与感觉神经元，调节疼痛 states.然而，SC对PPN的贡献机制在很大程度上是未知的。线粒体失调 在神经元中，已被确定为与PPN相关的机制。两项研究表明， 一个关键的线粒体蛋白缺失会导致进行性脱髓鞘神经病，目前还没有研究 将SC修复受体信号传导途径（其可以在治疗上靶向）与线粒体连接 与神经性疼痛相关的SC中的异质性和/或稳态。我们发现了低密度的 脂蛋白受体相关蛋白（LRP 1）作为损伤后SC修复的关键受体。的一个重要性质 LRP 1是其调节脂质代谢和葡萄糖稳态的能力，因此，控制细胞内的 生物能量学我们认为LRP 1直接调节SC中的线粒体动力学和功能，以优化 周围神经的生物能量稳态。我们之前的研究工作是研究SC LRP 1在神经炎症中的作用， 令人兴奋的新的初步数据显示，LRP 1调节SC细胞质中的线粒体数量 有髓神经纤维的存在，使我们能够验证这一假设在目标1中，我们将研究SC的监管 线粒体异质性和生物能量学。我们建议在整个神经裂解物和分离的分析， 来自转基因小鼠的原代SC培养物（mSC），其中LRP 1从SC中有条件地缺失（scLRP 1-/-）。 我们计划用一种创新的LRP 1激活剂挑战mSC代谢，目前正在进行II期临床试验。我们 我们还将测试LRP 1调节的SC线粒体如何通过化疗药物治疗对应激作出反应 已知会诱发PPN在目标2中，我们将使用无偏的蛋白质组学来鉴定线粒体蛋白质组 分别从scLRP 1-/-和scLRP 1 +/+分离的神经病性和幼稚SC中筛选。然后我们建立在 SC中LRP 1的条件性缺失如何触发PPN并应用全局非靶向的蛋白质蓝图 代谢组学，以确定关键代谢物的变化。这些研究将揭示关于 与PPN相关的SC的线粒体动力学、含量和代谢。

PROJECT SUMMARY Peripheral neuropathies have heterogeneous etiologies and can emerge from traumatic, metabolic and chemotherapy induced events. Neuropathic pain is a major symptom of peripheral neuropathies, which is characterized by spontaneous pain, burning and paresthesia. Often it is associated with devastating losses of quality of life. Currently, treatments are limited and burden patients with side effects and addiction. Identifying novel strategies for pain treatment addresses a substantial unmet medical need. Research in mechanisms of painful peripheral neuropathy (PPN) has largely focused on sensory neurons, however, peripheral glia, Schwann cells (SCs), emerge as an essential component of the functional unit with sensory neurons that regulate pain states. Yet, mechanisms underlying SC contributions to PPN are largely unknown. Mitochondria dysregulation in neurons has been identified as a mechanism associated with PPN. Although, two studies show that genetic deletion of a key mitochondrial protein elicits a progressive demyelinating neuropathy, there are no studies linking a SC repair receptor signaling pathway (which could be targeted therapeutically) with mitochondria heterogeneities and/or homeostasis in SCs, relevant to neuropathic pain. We identified the low-density lipoprotein receptor related protein (LRP1) as a key SC repair receptor after injury. An important property of LRP1 is its ability to regulate lipid metabolism and glucose homeostasis, and therefore, control cellular bioenergetics. We propose that LRP1 directly regulates mitochondrial dynamics and function in SCs to optimize bioenergetic homeostasis in peripheral nerves. Our prior work investigating SC LRP1 in neuroinflammation and pain, and exciting new preliminary data showing LRP1 regulation of mitochondria numbers in the SC cytoplasm of myelinated fibers, uniquely positions us to test this hypothesis. In Aim 1, we will examine regulation of SC mitochondrial heterogeneities and bioenergetics. We propose analyses in whole nerve lysates and isolated primary SC cultures (mSC) from transgenic mice in which LRP1 is conditionally deleted from SCs (scLRP1-/-). We plan to challenge mSC metabolism with an innovative LRP1 activator, currently in phase II clinical trials. We also will test how LRP1 regulated SC mitochondria respond to stress by treatment with a chemotherapy agent known to induce PPN. In Aim 2, we will identify the mitochondrial proteome by using an unbiased proteomics screen from neuropathic and naive SCs isolated from scLRP1-/- and scLRP1+/+, respectively. We then build on the protein blueprint of how conditional deletion of LRP1 in SCs triggers PPN and apply global untargeted metabolomics to identify key metabolite changes. These studies will reveal entirely new information about mitochondria dynamics, content, and metabolism of SCs related to PPN.