miR-155-5p 通过抑制 SIRT1 促进硝化甘油诱导的慢性偏头痛小鼠模型中的神经炎症和中枢敏化。
MicroRNA-155-5p promotes neuroinflammation and central sensitization via inhibiting SIRT1 in a nitroglycerin-induced chronic migraine mouse model.
机构信息
Laboratory Research Center, The First Affiliated Hospital of Chongqing Medical University, 1st You Yi Road, Yu Zhong, Chongqing, 400016, China.
Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China.
出版信息
J Neuroinflammation. 2021 Dec 10;18(1):287. doi: 10.1186/s12974-021-02342-5.
BACKGROUND
Previous studies have confirmed that the microglial activation and subsequent inflammatory responses in the trigeminal nucleus caudalis (TNC) are involved in the central sensitization of chronic migraine (CM). MicroRNA-155-5p has been shown to modulate the polarization of microglia and participate in inflammatory processes in a variety of neurological diseases. However, its role in CM remains unclear. The purpose of this study was to determine the precise role of miR-155-5p in CM.
METHODS
A model of CM in C57BL/6 mice was established by recurrent intraperitoneal injection of nitroglycerin (NTG). Mechanical and thermal hyperalgesia were evaluated by Von Frey filaments and radiant heat. The expression of miR-155-5p was examined by qRT-PCR, and the mRNA and protein levels of silent information regulator 1(SIRT1) were measured by qRT-PCR, Western blotting (WB) and immunofluorescence (IF) analysis. The miR-155-5p antagomir, miR-155-5p agomir, SRT1720 (a SIRT1 activator) and EX527 (a SIRT1 inhibitor) were administered to confirm the effects of miR-155-5p and SIRT1 on neuroinflammation and the central sensitization of CM. ELISA, WB and IF assays were applied to evaluate the expression of TNF-α, myeloperoxidase (MPO), IL-10, p-ERK, p-CREB, calcitonin gene-related peptide (CGRP), c-Fos and microglial activation. The cellular localization of SIRT1 was illustrated by IF.
RESULTS
After the NTG-induced mouse model of CM was established, the expression of miR-155-5p was increased. The level of SIRT1 was decreased, and partly colocalized with Iba1 in the TNC. The miR-155-5p antagomir and SRT1720 downregulated the expression of p-ERK, p-CREB, CGRP, and c-Fos, alleviating microglial activation and decreasing inflammatory substances (TNF-α, MPO). The administration of miR-155-5p agomir or EX527 exacerbated neuroinflammation and central sensitization. Importantly, the miR-155-5p agomir elevated CGRP and c-Fos expression and microglial activation, which could subsequently be alleviated by SRT1720.
CONCLUSIONS
These data demonstrate that upregulated miR-155-5p in the TNC participates in the central sensitization of CM. Inhibiting miR-155-5p alleviates neuroinflammation by activating SIRT1 in the TNC of CM mice.
背景
先前的研究已经证实，三叉神经脊核（TNC）中的小胶质细胞激活和随后的炎症反应参与了慢性偏头痛（CM）的中枢敏化。MicroRNA-155-5p 已被证明可以调节小胶质细胞的极化，并参与多种神经疾病中的炎症过程。然而，其在 CM 中的作用尚不清楚。本研究旨在确定 miR-155-5p 在 CM 中的精确作用。
方法
通过反复腹腔内注射硝化甘油（NTG）建立 C57BL/6 小鼠 CM 模型。通过 Von Frey 纤维和辐射热评估机械和热痛觉过敏。通过 qRT-PCR 检测 miR-155-5p 的表达，通过 qRT-PCR、Western blot（WB）和免疫荧光（IF）分析检测沉默信息调节因子 1（SIRT1）的 mRNA 和蛋白水平。给予 miR-155-5p 拮抗剂、miR-155-5p 激动剂、SRT1720（SIRT1 激活剂）和 EX527（SIRT1 抑制剂）以确认 miR-155-5p 和 SIRT1 对神经炎症和 CM 中枢敏化的影响。应用 ELISA、WB 和 IF 测定评估 TNF-α、髓过氧化物酶（MPO）、IL-10、p-ERK、p-CREB、降钙素基因相关肽（CGRP）、c-Fos 和小胶质细胞激活的表达。通过 IF 显示 SIRT1 的细胞定位。
结果
在建立 NTG 诱导的 CM 小鼠模型后，miR-155-5p 的表达增加。SIRT1 水平降低，并部分与 TNC 中的 Iba1 共定位。miR-155-5p 拮抗剂和 SRT1720 下调 p-ERK、p-CREB、CGRP 和 c-Fos 的表达，减轻小胶质细胞激活和减少炎症物质（TNF-α、MPO）。给予 miR-155-5p 激动剂或 EX527 加剧了神经炎症和中枢敏化。重要的是，miR-155-5p 激动剂上调 CGRP 和 c-Fos 表达和小胶质细胞激活，随后可被 SRT1720 缓解。
结论
这些数据表明，TNC 中上调的 miR-155-5p 参与了 CM 的中枢敏化。抑制 miR-155-5p 通过在 CM 小鼠的 TNC 中激活 SIRT1 来减轻神经炎症。
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