针刺通过调控感觉神经元中的Piezo2-巨噬细胞互作改善小鼠骨关节炎疼痛的实验研究

关键词：针刺  骨关节炎  Piezo2  巨噬细胞  背根神经节

Keywords:acupuncture  osteoarthritis  Piezo2  macrophage  dorsal root ganglion

摘要：

      摘要 目的：探讨针刺足三里（ST36）穴位通过靶向感觉神经元中的 Piezo2-巨噬细胞互作改善骨关节炎（OA）疼痛的效果及机制。 方法：选用C57BL/6N小鼠，分为空白对照组（control，Con组）、碘乙酸钠模型组（monosodium iodoacetate，MIA组）、模型+针刺组（MIA+Acupuncture， MIA+Acu组）。采用MIA膝关节腔注射构建小鼠OA模型，对照组注射等体积无菌生理盐水。通过von Frey测试评估小鼠疼痛行为，利用免疫荧光、Western Blot、流式细胞术等检测背根神经节（dorsal root ganglion，DRG）中Piezo2表达及巨噬细胞浸润极化情况，并进行药理学干预以验证Piezo2-巨噬细胞交互作用。 结果：针刺ST36穴位可显著改善MIA小鼠的机械性痛觉敏化（P<0.0001），下调DRG中Piezo2的表达（P<0.0001），减少巨噬细胞浸润（P<0.05），促进巨噬细胞向M2表型极化（P<0.001）。药理学抑制Piezo2或清除巨噬细胞可降低小鼠疼痛反应（P<0.0001），且其效果与针刺治疗相似，表明Piezo2-巨噬细胞互作在针刺镇痛中发挥关键作用。 结论：针刺ST36穴位下调DRG中Piezo2表达，抑制了巨噬细胞浸润并促进其向M2表型极化，重塑DRG内的免疫微环境，进而缓解OA疼痛。

Abstract:

      Abstract Objective： To investigate the effect and mechanism of acupuncture at Zusanli （ST36） acupoint on osteoarthritis （OA） pain through targeting the Piezo2-macrophage interaction in sensory neurons, and to explore the underlying mechanism. Method： Male C57BL/6N mice were randomly divided into three groups：blank control（Con） group， monosodium iodoacetate（MIA） group， and MIA+Acupuncture（MIA+Acu） group. OA mouse models were induced via MIA injection into the knee joint cavity， while the control group received an equal volume of sterile saline. Mechanical sensitivity was assessed using von Frey testing. Expression of Piezo2 in the dorsal root ganglion(DRG), as well as macrophage infiltration and polarization, were evaluated using immunofluorescence, Western blotting, and flow cytometry. Pharmacological interventions were performed to verify the Piezo2-macrophage interaction. Result： Acupuncture at ST36 significantly reversed MIA-induced mechanical allodynia （P<0.0001）， downregulated Piezo2 expression in DRG （P<0.0001）， reduced macrophage infiltration （P<0.05）， and promoted M2 macrophage polarization （P<0.001）. Pharmacological inhibition of Piezo2 or depletion of macrophages decreased pain responses （P<0.0001）， with effects similar to acupuncture treatment， indicating that the Piezo2-macrophage interaction plays a key role in acupuncture analgesia. Conclusion： Acupuncture at ST36 downregulates Piezo2 expression on sensory neurons in the DRG， inhibits macrophage infiltration and promotes their polarization toward the M2 phenotype， and remodels the immune microenvironment， and thereby alleviates OA pain.