Cell Specific Identification of IL-1R Actions in Acute and Chronic Pain

摘要 炎性和抗炎性细胞因子参与痛觉传递中神经元的过度兴奋 途径。白细胞介素-1（IL-1）是一种炎症细胞因子，参与多种神经免疫反应。 特别地，已经证明IL-1诱导急性疼痛，降低吗啡镇痛活性， 参与耐受性发展，并且是慢性神经性和炎性疼痛所必需的。这 已经以许多方式进行了研究，包括使用内源性IL-1受体拮抗剂，以及使用IL-1和 IL-1 R敲除小鼠。从机理的角度来看，这些实验的问题在于， 在脑中的多种细胞类型中内源性发现，包括星形胶质细胞，小胶质细胞，内皮细胞， 和神经元，并且整体敲除实验不能确定介导IL-1作用的细胞类型。的 开发新的遗传模型，其中IL-1受体IL-1 R1可以被敲除， 恢复（IL-1 R1 r/r）从一个整体敲除，在大脑，脊髓和背根的个别细胞类型 神经节允许更特异地鉴定IL-1对疼痛的作用。具体目标1 将在5种小鼠基因型中研究吗啡镇痛和耐受性的发展，野生型，全局IL-1 R1 KO， 和小鼠，其中IL-1 R1受体被选择性地恢复到神经元、内皮细胞和星形胶质细胞中。我们 我们希望发现，全球KO动物和两种恢复的小鼠基因型将具有更有效的， 如文献中所述，延长吗啡镇痛和降低耐受性发展。此外，委员会认为， 其中一个恢复的小鼠品系将表现出与吗啡活性降低的野生型动物一样的行为 宽容发展。目的2将检查两种慢性疼痛模型，脊神经结扎和完全性疼痛。 弗氏佐剂，使用相同的小鼠基因型，以确定哪种细胞类型介导的发展 慢性疼痛。目的3通过c-Fos-Cre/ERT 2与IL-1 R1 r/r小鼠杂交建立一种新的小鼠模型 （TRAP 2）小鼠。有了这种新的遗传模型，IL-1 R1将只在经历了以下过程的小鼠中恢复： 一些疼痛刺激这些新的遗传模型的使用将确定IL-1对阿片类药物的作用。 镇痛和疼痛，以特定的细胞类型，并制定一项合作，将能够确定 IL-1的作用机制，在未来的R 01应用。

Abstract Inflammatory and anti-inflammatory cytokines contribute to neuronal hyperexcitability in pain transmission pathways. One of the inflammatory cytokines, Interleukin-1 (IL-1), is involved in many neuroimmune responses. In particular, it has been demonstrated that IL-1 induces acute pain, reduces morphine analgesic activity, is involved in tolerance development, and is necessary for chronic neuropathic and inflammatory pain. This has been studied in many ways, including use of an endogenous IL-1 receptor antagonist, and the use of IL-1 and IL-1R knockout mice. The problem with these experiments from a mechanistic standpoint is that IL-1 receptors are found endogenously on a variety of cell types in the brain, including astrocytes, microglia, endothelial cells, and neurons, and global knockout experiments can't define the cell types that mediate the actions of IL-1. The development of novel genetic models, in which the IL-1 receptor, IL-1R1, can be reciprocally knocked out and restored (IL-1R1r/r) from a global knockout, into individual cell types in the brain, spinal cord, and dorsal root ganglion permits a much more specific identification of the actions of IL-1 with respect to pain. Specific Aim 1 will study morphine analgesia and tolerance development in 5 mouse genotypes, wild type, global IL-1R1 KO, and mice in which the IL-1R1 receptor is restored selectively into neurons, endothelial cells, and astrocytes. We expect to find that the global KO animals and two of the restored mouse genotypes will have more potent and prolonged morphine analgesia and reduced tolerance development, as described in the literature. Furthermore, one of the restored mouse lines will act like the wild type animals with reduced morphine activity and will exhibit tolerance development. Aim 2 will examine two chronic pain models, spinal nerve ligation and Complete Freund's Adjuvant, using the same mouse genotypes, to determine which cell type mediates the development of chronic pain. Aim 3 will develop a new mouse model by crossing the IL-1R1r/r mice with c-Fos-Cre/ERT2 (TRAP2) mice. With this new genetic model, IL-1R1 will be restored only in mice that have been subjected to some pain stimulus. The use of these novel genetic models will pinpoint the actions of IL-1 with respect to opioid analgesia and pain to specific cell types and develop a collaboration that will be able to determine the mechanisms of IL-1 actions, in future R01 applications.