远端脊髓节段星形胶质细胞活化介导神经损伤诱发的播散性疼痛  

Activation of astrocytes in distal segments of the spinal cord mediating widespread pain induced by peripheral nerve injury

作　　者：金思璇 于宁 孙丰润 马超[1,2] JIN Si-xuan;YU Ning;SUN Feng-run;MA Chao(Department of Anatomy,Histology and Embryology,Institute of Basic Medical Sciences,Chinese Academy of Medical Sciences,School of Basic Medicine,Peking Union Medical College,Beijing 10005,China;State Key Laboratory of Common Mechanism Research for Major Diseases,Beijing 10005,China)

机构地区：[1]中国医学科学院基础医学研究所,北京协和医学院基础学院人体解剖学与组织学胚胎学系,北京100005 [2]重大疾病共性机制研究全国重点实验室,北京100005

出　　处：《解剖学报》2024年第2期167-173,共7页Acta Anatomica Sinica

基　　金：北京协和医学院基础医学院研究生创新基金(#2022xscx-04);科技创新2030-“脑科学与类脑”研究重大项目(2021ZD0201100 Task 1#2021ZD0201101);中国医学科学院医学与健康科技创新工程项目(CIFMS#2021-12M-1-025)。

摘　　要：目的探讨中枢神经系统中远端脊髓节段胶质细胞活化与播散性疼痛的关系。方法50只雌性大鼠随机分为假手术(sham)组、眶下神经慢性压迫性损伤(CCI-ION)组、CCI-ION+米诺环素(Mino)组、CCI-ION+L-2-氨基己二酸(LAA)组和CCI-ION+生理盐水(NS)组,每组n=10。建立CCI-ION模型,鞘内注射Mino、LAA和生理盐水,利用免疫荧光染色分别检测延髓、颈段、胸段、腰段脊髓节段中活化的星形胶质细胞标记物自身免疫性胶质纤维酸性蛋白(GFAP)和小胶质细胞标记物离子钙结合衔接分子1(IBA1);在第7、14、21、28天,使用von Frey纤维丝评估大鼠触须垫机械痛阈值,并采用电子von Frey仪测量大鼠前足、胸部及后足机械痛阈值,用辐射热痛刺激仪测量大鼠后足热痛阈值。结果结果显示,鞘内注射Mino抑制小胶质细胞后,各脊髓节段活化的小胶质细胞减少,鞘内注射LAA抑制星形胶质细胞后,各脊髓节段活化的星形胶质细胞减少,且注射Mino和LAA后,模型组大鼠触须垫机械痛阈升高,损伤部位的神经病理性疼痛缓解。鞘内注射Mino后,模型组大鼠后足热痛阈和机械痛阈未发现明显变化;鞘内注射LAA后,后足热痛阈和机械痛阈显著升高,播散性疼痛缓解。结论远端脊髓节段星形胶质细胞活化介导外周神经损伤诱发的播散性疼痛。Objective To discuss the relationship between activated glia cells in distal segment of the spinal cord and widespread pain.Methods Fifty female rats were randomly divided into sham group,the chronic constriction injury of the infraorbital nerve(CCI-ION)group,CCI-ION+minocycline(Mino)group,CCI-ION+L-2-aminoadipic acid(LAA)group,and CCI-ION+normal saline(NS)group,n=10 for each group.CCI-ION model was established and Mino,LAA,and normal saline were delivered intrathecally to CCI-ION rats.Immunofluorescence staining was used to detect activated astrocytes and microglia in the medulla oblongata,cervical,thoracic,and lumbar spinal cord segments.On the 7th,14th,21st,28th day,von Frey filaments were used to evaluate the mechanical withdrawal threshold of vibrissa pad,and electronic von Frey tactile pain meter was used to measure the mechanical withdrawal threshold of front paw,chest and hind paw.The radiant thermal stimulator was used to measure the thermal withdrawal threshold of hind paw.Results After intrathecal injection of Mino to inhibit microglia,the activated microglia in each spinal cord segment decreased.Moreover,inhibiting astrocytes by using LAA significantly reduced activated astrocytes in spinal dorsal horn from distal segments.Behavioral assay showed that after intrathecal injection of Mino and LAA,the mechanical allodynia of vibrissa pad in CCI-ION rats was relieved.However,there was no significant difference(P>0.05)in the thermal and mechanical withdrawal thresholds in the hind paw of CCI-ION rats after intrathecal injection of Mino,while intrathecal injection of LAA significantly increased the thermal and mechanical withdrawal thresholds in the hind paw,indicating the relief of widespread pain induced by CCI-ION.Conclusion The activated astrocytes in distal segments of the spinal cord mediated CCI-IONinduced widespread pain.

关 键 词：慢性痛 播散性疼痛 小胶质细胞 星形胶质细胞 免疫荧光 大鼠 

分 类 号：R322.81[医药卫生—人体解剖和组织胚胎学]