A transcriptional toolbox for exploring peripheral neuro-immune interactions

Correct communication between immune cells and peripheral neurons is crucial for the protection of our bodies. Its breakdown is observed in many common, often painful conditions, including arthritis, neuropathies and inflammatory bowel or bladder disease. Here, we have characterised the immune response in a mouse model of neuropathic pain using flow cytometry and cell-type specific RNA sequencing (RNA-seq). We found few striking sex differences, but a very persistent inflammatory response, with increased numbers of monocytes and macrophages up to 3½ months after the initial injury. This raises the question of whether the commonly used categorisation of pain into “inflammatory” and “neuropathic” is one that is mechanistically appropriate. Finally, we collated our data with other published RNA-seq datasets on neurons, satellite glial cells, macrophages and Schwann cells in naïve and nerve injury states. The result is a practical web-based tool for the transcriptional data-mining of peripheral neuroimmune interactions. Overall design: We have characterised the immune response in a mouse model of neuropathic pain using flow cytometry and cell-type specific RNA sequencing (RNA-seq).

免疫细胞与外周神经元之间的正常通信对机体防御至关重要。此类通信的功能失调可见于多种常见且常伴疼痛的疾病，包括关节炎、神经病变、炎症性肠病及炎症性膀胱疾病。本研究借助流式细胞术（flow cytometry）与细胞类型特异性RNA测序（RNA-seq），对神经病理性疼痛小鼠模型中的免疫应答进行了系统表征。研究未观察到显著的性别差异，但检测到持续时间极久的炎症应答：初始损伤后长达3.5个月内，单核细胞与巨噬细胞的数量均显著升高。这一发现引发了一个关键疑问：当前将疼痛普遍划分为"炎症性疼痛"与"神经病理性疼痛"的分类方式，是否具备机制层面的合理性？最后，我们将本研究数据与其他已发表的RNA测序数据集进行了整合，这些数据集涵盖了未受干预（naïve）及神经损伤状态下的神经元、卫星胶质细胞（satellite glial cells）、巨噬细胞与雪旺细胞（Schwann cells）的转录组信息。最终构建了一款实用的网页端工具，可用于外周神经免疫互作的转录组数据挖掘。实验整体设计：本研究借助流式细胞术（flow cytometry）与细胞类型特异性RNA测序（RNA-seq），对神经病理性疼痛小鼠模型中的免疫应答进行了系统表征。