黄芪甲苷对EAE小鼠轴突修复和再生的促进作用机制  

Promotion mechanism of astragaloside on axon repair and regeneration in experimental autoimmune encephalomyelitis mice

作　　者：刘建春 张红珍 王青 樊慧杰 宋丽娟 柴智 马存根 Liu Jian-Chun;Zhang Hong-Zhen;Wang Qing;Fan Hui-Jie;Song Li-Juan;Chai Zhi;Ma Cun-Gen(Research Center of Neurobiology,Shanxi University of Chinese Medicine/Key Laboratory of Multiple Sclerosis Supplementing Qi and Promoting Blood Circulation of State Administration of Traditional Chinese Medicine,Jinzhong,Shanxi 030619,China;Institute of Brain Science,Shanxi Datong University,Datong,Shanxi 037009,China)

机构地区：[1]山西中医药大学神经生物学研究中心/国家中医药管理局多发性硬化益气活血重点研究室,山西晋中030619 [2]山西大同大学脑科学研究所,山西大同037009

出　　处：《解放军医学杂志》2024年第8期914-921,共8页Medical Journal of Chinese People's Liberation Army

基　　金：国家自然科学基金(81903596);山西省科技创新青年人才团队项目(202204051001028);山西省卫健委医学科技领军团队项目(2020TD05);山西中医药大学科技创新培育计划“太行本草”专项(2022PY-TH-31)。

摘　　要：目的观察黄芪甲苷(AS-Ⅳ)对实验性自身免疫性脑脊髓炎(EAE)小鼠轴突生长抑制因子A(Nogo-A)及其下游通路蛋白Rho相关卷曲螺旋激酶2(ROCK2)的影响,探究其对轴突修复和再生的促进作用机制。方法采用髓鞘少突胶质细胞糖蛋白35-55多肽(MOG35-55)皮下注射C57BL/6雌性小鼠制备EAE模型;将小鼠随机分为EAE组、AS-Ⅳ组,每组8只。于免疫后第3天开始,EAE组腹腔注射PBS;AS-Ⅳ组腹腔注射AS-Ⅳ30 mg/(kg.d),1次/d,0.2 ml/次,连续给药25 d。免疫后第28天,取小鼠脊髓,采用免疫荧光法检测脊髓中生长相关蛋白43(GAP-43)、神经元核心抗原(NeuN)、微管相关蛋白2(MAP-2)、胶质纤维酸性蛋白(GFAP)和离子钙结合衔接分子1(Iba1)的表达水平;实时荧光定量PCR(qRT-PCR)检测GAP-43、Nogo-A、Nogo受体(NgR)基因mRNA表达水平;Western blotting检测GAP-43、Nogo-A、ROCK2、磷酸化肌球蛋白磷酸酶(p-MYPT1)、B淋巴细胞瘤-2(Bcl-2)蛋白和Bcl-2关联X蛋白(Bax)表达水平。结果与EAE组比较,AS-Ⅳ组小鼠脊髓中星形胶质细胞GFAP和小胶质细胞Iba1的阳性表达率均明显下降(P<0.01,P<0.001);NeuN和MAP-2阳性表达率均增高(P<0.001,P<0.05);抗凋亡因子Bcl-2表达水平增高(P<0.001),促凋亡因子Bax表达水平降低(P<0.05),Bcl-2/Bax比值升高(P<0.05);GAP-43蛋白表达水平增高(P<0.05);神经再生抑制因子NgR和ROCK2基因mRNA表达水平均下调(P<0.001,P<0.05);Nogo-A、ROCK2和p-MYPT1蛋白表达水平均降低(P<0.05或P<0.001)。结论AS-Ⅳ可通过抑制Nogo-A及其下游通路分子ROCK2,抑制EAE小鼠小胶质细胞和星形胶质细胞的激活及神经元凋亡,进而促进GAP-43、NeuN及MAP-2的表达,减轻神经元损伤,促进轴突修复和再生。Objective To investigate the effects of astragalosideⅣ(AS-Ⅳ)on axon growth inhibitory factor A(Nogo-A)and its downstream pathway protein RHO-associated coiled spiral kinase 2(ROCK2)in experimental autoimmune encephalomyelitis(EAE)mice,and to explore the mechanism by which it promotes axon repair and regeneration.Methods EAE model was induced in C57BL/6 female mice by subcutaneous injection of myelin oligodendrocyte glycoprotein 35-55(MOG35-55).Mice were randomly divided into EAE group and AS-Ⅳgroup(n=8 per group).EAE group received intraperitoneal injection of PBS on the 3rd day post immunization,while ASⅣgroup was administered ASⅣat a dosage of 30mg/(kg.d)once daily,0.2 ml per injection,for 25 consecutive days.On the 28th day post-immunization,the expression levels of growth-associated protein 43(GAP-43),neuronal core antigen(NeuN),microtubule associated protein 2(MAP-2),glial fibroacidic protein(GFAP),and Iba1 in the spinal cord were detected using immunofluorescence assay.Real-time fluorescence quantitative PCR(qRT-PCR)was conducted to detect mRNA expression levels of GAP-43,Nogo-A,and Nogo receptor(NgR)genes.Western blotting was utilized to determine the expression levels of GAP-43,Nogo-A,ROCK2,phosphorylated myosin phosphatase(p-MYPT1),B-lymphoblastoma-2(Bcl-2),and Bcl-2 associated X protein(Bax).Results Compared with EAE group,AS-Ⅳtreatment significantly reduced the positive cell expression rates of Iba1 microglia and GFAP astrocyte in spinal cord(P<0.01 and P<0.001,respectively),while it also increased the positive expression rates of NeuN and MAP-2(P<0.001 and P<0.05,respectively).The treatment also upregulated the expression level of anti apoptotic factor Bcl-2(P<0.001)and downregulated the expression level of pro-apoptotic factor Bax(P<0.05),leading to an increase in Bcl-2/Bax ratio(P<0.05).Furthermore,ASⅣenhanced the expression of GAP-43 protein(P<0.05)and decreased the mRNA expression levels of neuroregeneration inhibitor Nogo receptor(NgR)and ROCK2 gene(P<0.001,P<0.05,respectively);as w

关 键 词：自身免疫性脑脊髓炎 黄芪甲苷 轴突生长抑制因子 凋亡 轴突再生 

分 类 号：R285.5[医药卫生—中药学] R744.5[医药卫生—中医学]