Spinal cord microglia plays a crucial role in the pathogenesis of neuropathic pain. However, the mechanisms underlying spinal microglial activation during neuropathic pain remain incompletely determined. Here, we investigated the role of Pellino1 (Peli1) and its interplay with spinal microglial activation in neuropathic pain. In this study, we examined the effects of Peli1 on pain hypersensitivity and spinal microglial activation after chronic constriction injury (CCI) of the sciatic nerve in mice. The molecular mechanisms involved in Peli1-mediated hyperalgesia were determined by western blot, immunofluorescence, quantitative polymerase chain reaction (qPCR), and enzyme-linked immunosorbent assay (ELISA). We utilized immunoprecipitation to examine the ubiquitination of tumor necrosis factor receptor-associated factor 6 (TRAF6) following CCI. In addition, we explored the effect of Peli1 on BV2 microglial cells in response to lipopolysaccharide (LPS) challenge. We found that CCI induced a significant increase in the levels of Peli1, which was present in the great majority of microglia in the spinal dorsal horn. Our results showed that spinal Peli1 contributed to the induction and maintenance of CCI-induced neuropathic pain. The biochemical data revealed that CCI-induced Peli1 in the spinal cord significantly increased mitogen-activated protein kinase (MAPK) phosphorylation, activated nuclear factor kappa B (NF-κB), and enhanced the production of proinflammatory cytokines, accompanied by spinal microglial activation. Peli1 additionally was able to promote K63-linked ubiquitination of TRAF6 in the ipsilateral spinal cord following CCI. Furthermore, we demonstrated that Peli1 in microglial cells significantly enhanced inflammatory reactions after LPS treatment. These results suggest that the upregulation of spinal Peli1 is essential for the pathogenesis of neuropathic pain via Peli1-dependent mobilization of spinal cord microglia, activation of MAPK/NF-κB signaling, and production of proinflammatory cytokines. Modulation of Peli1 may serve as a potential approach for the treatment of neuropathic pain.

中文翻译：

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Pellino1 通过调节脊髓中的 MAPK/NF-κB 信号传导来调节神经性疼痛以及小胶质细胞激活


脊髓小胶质细胞在神经性疼痛的发病机制中起着至关重要的作用。然而，神经性疼痛期间脊髓小胶质细胞激活的机制仍未完全确定。在这里，我们研究了 Pellino1 (Peli1) 的作用及其与脊髓小胶质细胞激活在神经性疼痛中的相互作用。在这项研究中，我们研究了 Peli1 对小鼠坐骨神经慢性收缩损伤 (CCI) 后疼痛超敏性和脊髓小胶质细胞激活的影响。通过蛋白质印迹、免疫荧光、定量聚合酶链反应 (qPCR) 和酶联免疫吸附测定 (ELISA) 确定 Peli1 介导的痛觉过敏的分子机制。我们利用免疫沉淀法检查 CCI 后肿瘤坏死因子受体相关因子 6 (TRAF6) 的泛素化情况。此外，我们还探讨了 Peli1 对 BV2 小胶质细胞响应脂多糖 (LPS) 挑战的影响。我们发现 CCI 诱导 Peli1 水平显着增加，Peli1 存在于脊髓背角的绝大多数小胶质细胞中。我们的结果表明脊髓 Peli1 有助于 CCI 诱导的神经性疼痛的诱导和维持。生化数据显示，CCI诱导的脊髓中的Peli1显着增加了丝裂原激活蛋白激酶（MAPK）的磷酸化，激活了核因子κB（NF-κB），并增强了促炎细胞因子的产生，同时伴随着脊髓小胶质细胞的激活。 Peli1还能够在CCI后促进同侧脊髓中K63相关的TRAF6泛素化。此外，我们证明小胶质细胞中的 Peli1 在 LPS 处理后显着增强炎症反应。 这些结果表明，脊髓 Peli1 的上调对于神经性疼痛的发病机制至关重要，通过 Peli1 依赖性脊髓小胶质细胞的动员、MAPK/NF-κB 信号的激活以及促炎细胞因子的产生。 Peli1 的调节可能作为治疗神经性疼痛的潜在方法。