Peripheral mechanisms of central neuropathic pain in multiple sclerosis

多发性硬化症中枢神经病理性疼痛的外周机制

• 批准号: 10285258
• 负责人: Kayla Lee Nguyen
• 金额: $ 6.64万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-08-15 至 2023-01-14
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10285258
• 关键词: Ablation; Action Potentials; Address; Affective; Afferent Neurons; Amyloid beta-Protein; Animal Model; Behavioral; Brain; C Fiber; Calcium; Caliber; Capsaicin; Career Choice; Cells; Data; Development; Diabetic Neuropathies; Dorsal; Electrophysiology (science); Experimental Autoimmune Encephalomyelitis; Family member; Fiber; Fire - disasters; Flagellin; Frequencies; Fura-2; Future; Goals; Halorhodopsins; Hypersensitivity; Image; Implant; Inflammatory; Injections; Injury; Interneurons; Intervention; Isolectin; Knockout Mice; Knowledge; Laboratories; Learning; Lesion; Light; Literature; Maintenance; Measurement; Measures; Mechanics; Methods; Modeling; Multiple Sclerosis; Mus; Neonatal; Neurons; Nociceptors; Pain; Pain Clinics; Pain Research; Pain management; Pathologic; Patients; Peripheral; Pharmaceutical Preparations; Phosphotransferases; Population; Posterior Horn Cells; Process; Reflex action; Reporting; Skin; Slice; Spinal; Spinal Cord; Spinal Ganglia; Spinal cord injury; Stimulus; Substantia Gelatinosa; Tamoxifen; Techniques; Testing; Therapeutic; Transgenic Organisms; Traumatic Nerve Injury; Tropomyosin; Woman; chronic pain; conditional knockout; inflammatory pain; mechanical allodynia; member; multiple sclerosis patient; optogenetics; pain relief; painful neuropathy; receptor; response; somatosensory; subcutaneous; therapeutically effective

Nguyen, Kayla PROJECT SUMMARY/ABSTRACT Neuropathic Pain (NP) afflicts over 50% of patients with multiple sclerosis (MS), yet current treatments for pain relief are inadequate, in part because mechanisms that drive MS pain are poorly understood. In a widely-used animal model of MS, experimental autoimmune encephalomyelitis (EAE), recent electrophysiological recordings of primary afferent neurons (PANs) in the dorsal root ganglion (DRG) revealed: 1) hyperexcitability of medium- to-large diameter neurons and 2) an increase in afterhyperpolarization of small-diameter fibers. These data provide the premise for my long-term goal to investigate the sensitization mechanisms at PANs that drive NP in the EAE model. With behavioral, transgenic, and ablation techniques, I propose to assess the contribution of A and C-fibers to MS pain upon testing the overall hypothesis that EAE produces a persistent hyperexcitability of A and/or C-nociceptors (Aim 1,2) that is associated with increased activity of dorsal horn (DH) neurons (Aim 3) that then drives NP. Aim 1 uses neuronal ablation strategies to identify which subpopulations of primary afferent neurons contribute to NP in EAE. I will use simple conventional neuronal ablation strategies (neonatal capsaicin, intrathecal capsaicin, intrathecal IB4-saporin, intraplantar flagellin/QX-314), followed by a more labor-intensive but powerful conditional knockout approach to eliminate the activity of increasingly precise PAN subsets. I predict that the proposed interventions will reduce key indicators of EAE-induced pain: mechanical and cold hypersensitivity (reflexive pain) and conditioned place aversion (affective pain). Aim 2 uses chemogenetics and optogenetics to test the hypothesis that either Mrgprd- or TrkC-expressing PANs are necessary for NP in EAE. I predict that CreER selective manipulations to inhibit either the MrgprD+ subset of IB4 neurons or the TrkC+ subset of myelinated neurons (decision driven by the results of Aim 1a-b) will reduce EAE mechanical and cold hypersensitivity. Aim 3 will test the hypothesis that EAE sensitizes the somatosensory stimulus-induced activation of spinal interneurons and projection neurons. Our laboratory reported that EAE increases the activity of dorsal horn neurons as measured by the expression of pERK. I propose to extend these studies with a more powerful measure of neuronal activity using spinal cord slice Fura-2 calcium imaging, and by assessing the activity not only of interneurons, but also of projection neurons. The Pittsburgh Center for Pain Research will provide guidance, support, and learning opportunities that will promote the development of my scientific and investigative career aspirations.

nguyen，凯拉 项目摘要/摘要 超过50％的多发性硬化症患者（MS）的神经性疼痛（NP）遭受了疼痛的治疗 缓解是不足的，部分原因是使MS疼痛的机制理解不足。在广泛使用中 MS的动物模型，实验性自身免疫性脑脊髓炎（EAE），最近的电生理记录 背根神经节（DRG）中的原发性传入神经元（PAN）显示：1）培养基过度刺激性 直径直径神经元和2）小直径纤维的超极化增加。这些数据 提供我的长期目标的前提，以调查驱动NP的PANS的敏化机制 EAE模型。通过行为，转基因和消融技术，我建议评估A的贡献 在测试EAE产生持续过度刺激性的总体假设后，C纤维在MS上疼痛 A和/或C-Nocptors（AIM 1,2）与背角（DH）神经元的活动增加有关（AIM 3） 然后驱动NP。 AIM 1使用神经元消融策略来确定主要传入的哪些亚群 神经元在EAE中为NP做出了贡献。我将使用简单的常规神经元消融策略（新生儿辣椒素， 鞘内辣椒素，鞘内IB4-糖粉，扁豆内鞭毛蛋白/QX-314），其次是劳动密集型的 但是强大的有条件敲除方法可以消除日益精确的锅子集的活性。我预测 提出的干预措施将减少EAE引起的疼痛的关键指标：机械和寒冷 超敏反应（反射性疼痛）和条件的场所厌恶（情感疼痛）。 AIM 2使用化学遗传学和 光遗传学以检验以下假设：EAE中的NP是必需的MRGPRD或表达TRKC的锅。 我预测Creer选择性操作会抑制IB4神经元的MRGPRD+子集或TRKC+ 骨髓神经元的子集（由AIM 1A-B的结果驱动的决定）将减少EAE机械和冷 高敏性。 AIM 3将测试EAE敏感刺激诱导的假设 脊柱中间神经元和投影神经元的激活。我们的实验室报告说EAE增加了活动 通过PERK的表达测量的背角神经元的。我建议将这些研究扩展到更多 使用脊髓切片Fura-2钙成像的有力测量神经元活性，并通过评估 不仅是中间神经元的活性，而且是投射神经元的活性。匹兹堡疼痛研究中心将 提供指导，支持和学习机会，以促进我的科学发展和 调查职业愿望。