Microglia and S1PR1 Signaling in Multiple Sclerosis Associated Neuropathic Pain

多发性硬化症相关神经病理性疼痛中的小胶质细胞和 S1PR1 信号转导

基本信息

批准号：
10537095
负责人：
Sydney Lamerand
金额：
$ 4.68万
依托单位：
UNIVERSITY OF PITTSBURGH AT PITTSBURGH
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-09-01 至 2025-08-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10537095
关键词：
Address Affect Agonist Analgesics Attenuated Behavior Behavioral Binding Biological Assay CNS autoimmune disease Chronic Cognitive Coupling Data Analyses Demyelinations Development Disease Experimental Autoimmune Encephalomyelitis Experimental Designs FDA approved Functional disorder Future G-Protein-Coupled Receptors GTP-Binding Proteins Genetic Goals Hyperalgesia In Situ Inflammation Inflammatory Intervention Intrathecal Injections Knock-out Knowledge Laboratories Lead Learning Macrophage-1 Antigen Mediating Methods Microglia Modeling Motor Multiple Sclerosis Mus Neuraxis Neuroimmune system Neuropathy Oranges Pain management Pathway interactions Patients Peripheral Persons Pharmaceutical Preparations Pharmacology Primary Cell Cultures Property Proteins Publications Reporting Research Personnel Rodent Model Sensory Signal Transduction Site Sphingosine-1-Phosphate Receptor Spinal Spinal Cord Testing Training Transgenic Organisms Up-Regulation allodynia antagonist behavioral pharmacology chronic pain comorbidity cytokine design experimental study intraperitoneal motor symptom mouse model multiple sclerosis treatment non-opioid analgesic pain behavior pain relief painful neuropathy prevent sphingosine 1-phosphate

项目摘要

Project Summary Neuropathic pain afflicts well over half of people living with multiple sclerosis (MS). Current treatments for MS were designed to delay motor symptom progression, but do not address MS associated neuropathic pain (MSNP). This is due in part to a lack of understanding about the underlying mechanisms that drive MSNP. The pathophysiology of MS includes proinflammatory microglial activation that is recapitulated in the experimental autoimmune encephalomyelitis (EAE) mouse model of MS. Both pharmacological inhibition and genetic knockout of microglia-specific proteins prevented the development of or suppressed established neuropathic pain behaviors in non-MS models of neuropathic pain. These studies indicate that microglia activation mediates the behavioral signs of MSNP. Fingolimod is an FDA approved MS drug that reduces allodynia and hyperalgesia in several rodent models of chronic pain, including peripheral neuropathic pain; however, the site and mechanism of antiallodynic action of fingolimod in central neuropathic pain, e.g., MSNP, remains unknown. Our laboratory reported that repeated administration of intraperitoneal fingolimod attenuated neuropathic pain-like behaviors in EAE, and these effects could be blocked by sphingosine-1-phosphate receptor 1 (S1PR1) antagonists or mimicked S1PR1 agonists. Our results raised the idea that fingolimod acts as an agonist at S1PR1 to elicit antiallodynic effects in EAE. Fingolimod reduces microglial activation in MS and primary cell culture. Because Gi-GPCR activation in microglia inhibits or blocks inflammation, and S1PR1 is a Gi-GPCR, I propose the overall hypothesis that fingolimod leads to S1PR1 activation and subsequent microglial inhibition that explains its anti-allodynic effects in EAE. Specific Aim 1 will test the hypothesis that spinal microglia-dependent mechanisms maintain MSNP. I will deplete microglia in the whole CNS or spinal cord (Aim 1.1/1.2) and chemogenetically inhibit spinal microglia (Aim 1.3) in EAE mice. I predict that each approach will attenuate EAE-induced allodynia. Specific Aim 2 will test the hypothesis that the spinal S1PR1 agonist actions of fingolimod reverse MSNP behavior through inhibition of EAE induced activation of pro-inflammatory microglia. Aim 2.1 predicts that intrathecal injection of fingolimod will reduce EAE-induced allodynia, and that this can be blocked by pre-administration of S1PR1 antagonists. Aim 2.2 predicts fingolimod will stimulate spinal G-protein coupling (assessed with in situ [35S]GTPγS binding assays) that is blocked with S1PR1 antagonists and increased in EAE, indicating an S1PR1 dependent mechanism that allows fingolimod to exert greater analgesic actions in EAE compared to controls. Aim 2.3 predicts that knockout of S1PR1 on microglia will prevent the antiallodynic effects of intrathecal fingolimod and S1PR1 agonists in EAE. This would indicate that fingolimod mediates MSNP through a microglial S1PR1-dependent mechanism.

项目概要目前治疗多发性硬化症 (MS) 的患者中，有超过一半患有神经性疼痛。旨在延缓运动症状进展，但不能解决多发性硬化症相关的神经性疼痛 (MSNP)。部分原因是缺乏对驱动 MSNP 的基本机制的了解。 MS 的病理生理学包括促炎性小胶质细胞激活，这在实验中得到了重述 MS 的自身免疫性脑脊髓炎 (EAE) 小鼠模型。敲除小胶质细胞特异性蛋白可阻止或抑制已确定的神经病的发展这些研究表明小胶质细胞激活介导非 MS 神经性疼痛模型的疼痛行为。 MSNP 的行为症状是 FDA 批准的 MS 药物，可减少异常性疼痛和痛觉过敏。然而，在几种慢性疼痛（包括周围神经性疼痛）的啮齿动物模型中，疼痛的部位和机制；我们的实验室仍不清楚芬戈莫德在中枢神经性疼痛（例如 MSNP）中的抗异常疼痛作用。据报道，腹腔内重复给予芬戈莫德可减轻神经病理性疼痛样行为 EAE，这些作用可以被 1-磷酸鞘氨醇受体 1 (S1PR1) 拮抗剂或模拟 S1PR1 激动剂我们的结果提出了芬戈莫德作为 S1PR1 激动剂来引发的想法。 EAE 中的抗异常疼痛作用。芬戈莫德减少 MS 和原代细胞培养物中的小胶质细胞活化，因为小胶质细胞中的 Gi-GPCR 活化。抑制或阻断炎症，并且 S1PR1 是 Gi-GPCR，我提出总体假设：芬戈莫德导致 S1PR1 激活和随后的小胶质细胞抑制，这解释了它在 EAE 中的抗异常疼痛作用。具体目标 1 将检验脊髓小胶质细胞依赖性机制维持 MSNP I 将耗尽的假设。整个中枢神经系统或脊髓中的小胶质细胞（目标 1.1/1.2）并通过化学遗传学抑制脊髓小胶质细胞（目标 1.3）在 EAE 小鼠中，我预测每种方法都会减轻 EAE 引起的异常性疼痛。假设芬戈莫德的脊髓 S1PR1 激动剂作用通过抑制 EAE 逆转 MSNP 行为目的 2.1 预测鞘内注射芬戈莫德会诱导促炎性小胶质细胞的激活。减少 EAE 引起的异常性疼痛，并且可以通过预先施用 S1PR1 拮抗剂来阻断。 2.2 预测芬戈莫德将刺激脊髓 G 蛋白偶联（通过原位 [35S]GTPγS 结合测定进行评估）被 S1PR1 拮抗剂阻断并导致 EAE 增加，表明 S1PR1 依赖机制与对照组相比，芬戈莫德在 EAE 中发挥更大的镇痛作用，Aim 2.3 预测基因敲除。 S1PR1 对小胶质细胞的影响将阻止鞘内注射芬戈莫德和 S1PR1 激动剂在 EAE 中的抗异常疼痛作用。这表明芬戈莫德通过小胶质细胞 S1PR1 依赖性机制介导 MSNP。