Small extracellular vesicles mediated signaling and pain

摘要 慢性疼痛是美国最普遍、致残和昂贵的公共卫生状况。 States.这个项目的目标是阐明如何利用身体自身的镇痛机制 来缓解疼痛我们建议研究30-150 nm的小细胞外囊泡（sEVs） 其通过循环将mRNA、miRNA、蛋白质和脂质介质转运至受体细胞。 sEV的摄取诱导受体细胞中基因表达的变化，因此，sEV发挥了重要作用。 在细胞间通讯中的重要作用。我们观察到来自RAW 264.7的sEV 巨噬细胞在完全弗氏佐剂（CFA）中显示治疗和预防功效 炎症性疼痛小鼠模型。我们的初步研究表明，小鼠血清来源的sEV 也给予预防时，鞘内注射在幼稚受体小鼠，两周， 之后，接受CFA的后爪注射。因此，接受sEV的小鼠可以记住这些， 刺激至少2周，并显示对CFA的减弱应答。如何长期 记忆发展是未知的。虽然慢性疼痛很普遍，但免疫策略并没有 我们的研究将为这一点提供理论依据和机制基础。 战略在这里，我们提出测试的假设，单核细胞/巨噬细胞来源的sEV亚群 是必要的，足以减弱炎性疼痛超敏反应，并赋予 预防。我们还将研究单核细胞/巨噬细胞sEV是否招募或促进抗- 脊髓背根神经节和脊髓免疫细胞炎性表型转换 CFA治疗前后原位定量免疫表型分析。最近的研究表明 小胶质细胞，即中枢神经系统中的巨噬细胞， 通过表观遗传修饰对延迟的二次损伤的反应。我们假设 单核细胞/巨噬细胞来源的sEV赋予脊髓小胶质细胞表观遗传免疫记忆 受体小鼠，给予能力，以减轻疼痛，从未来的侮辱，并有助于 sEV的预防作用。这些研究将阐明sEV在免疫中的作用。 调节和记忆。

Abstract Chronic pain is the most prevalent, disabling, and expensive public health condition in the United States. The goal of this project is to elucidate how to harness body’s own analgesic mechanisms to provide pain relief. We propose to investigate 30-150 nm small extracellular vesicles (sEVs) that transport mRNAs, miRNAs, proteins, and lipid mediators to recipient cells via circulation. Uptake of sEVs induce gene expression changes in recipient cells and thus, sEVs play an important role in intercellular communication. We observed that sEVs from RAW 264.7 macrophage cells show therapeutic and prophylactic efficacy in a complete Freud adjuvant (CFA) mouse model of inflammatory pain. Our preliminary studies show that mouse serum derived sEVs also conferred prophylaxis when injected intrathecally in naïve recipient mice that, two weeks later, received a hind paw injection of CFA. Thus, mice that received sEVs can remember this stimulation for at least 2 weeks and show an attenuated response to CFA. How this long-term memory develop is unknown. Though chronic pain is prevalent, an immunization strategy has not yet been tested and our studies will provide the rationale and mechanistic basis for such a strategy. Here we propose to test the hypothesis that monocyte/macrophage-derived sEV subsets in serum are necessary and sufficient to attenuate inflammatory pain hypersensitivity and confer prophylaxis. We will also investigate if monocyte/macrophage sEVs recruit, or promote anti- inflammatory phenotype switching of immune cells in dorsal root ganglion and spinal cord by quantitative immunophenotyping in situ, before and after CFA treatment. Recent studies show that microglia, the resident macrophages of the central nervous system can enhance or suppress responses to a delayed secondary insult through epigenetic modifications. We hypothesize that monocyte/macrophage-derived sEVs impart epigenetic immune memory in spinal microglia of recipient mice, granting the capacity to attenuate pain from a future insult and contribute to the prophylactic effect of sEVs. The studies proposed will elucidate the role of sEVs in immune regulation and memory.