Targeting central nervous system extracellular vesicles enhanced triiodothyronine remyelination effect on experimental autoimmune encephalomyelitis

The lack of targeted and high-efficiency drug delivery to the central nervous system(CNS)nidus is the main problem in the treatment of demyelinating disease.Extracellular vesicles(EVs)possess great promise as a drug delivery vector given their advanced features.However,clinical applications are limited because of their inadequate targeting ability and the“dilution effects”after systemic administration.Neural stem cells(NSCs)supply a plentiful source of EVs on account of their extraordinary capacity for self-renewal.Here,we have developed a novel therapeutic system using EVs from modified NSCs with high expressed ligand PDGF-A(EVPs)and achieve local delivery.It has been demonstrated that EVPs greatly enhance the target capability on oligodendrocyte lineage.Moreover,EVPs are used for embedding triiodothyronine(T3),a thyroid hormone that is critical for oligodendrocyte development but has serious side effects when systemically administered.Our results demonstrated that systemic injection of EVPs+T3,versus EVPs or T3 administration individually,markedly alleviated disease development,enhanced oligodendrocyte survival,inhibited myelin damage,and promoted myelin regeneration in the lesions of experimental autoimmune encephalomyelitis mice.Taken together,our findings showed that engineered EVPs possess a remarkable CNS lesion targeting potential that offers a potent therapeutic strategy for CNS demyelinating diseases as well as neuroinflammation.

Should mast cells be considered therapeutic targets in multiple sclerosis?

Mast cells are immune cells of the myeloid lineage that are found throughout the body,including the central nervous system.They perform many functions associated with innate and specific immunity,angiogenesis,and vascular homeostasis.Moreover,they have been implicated in a series of pathologies(e.g.,hypersensitivity reactions,tumors,and inflammatory disorders).In this review,we propose that this cell could be a relevant therapeutic target in multiple sclerosis,which is a central nervous system degenerative disease.To support this proposition,we describe the general biological properties of mast cells,their contribution to innate and specific immunity,and the participation of mast cells in the various stages of multiple sclerosis and experimental autoimmune encephalomyelitis development.The final part of this review is dedicated to an overview of the available mast cells immunomodulatory drugs and their activity on multiple sclerosis and experimental autoimmune encephalomyelitis,including our own experience related to the effect of ketotifen fumarate on experimental autoimmune encephalomyelitis evolution.

基于生物信息学的氧化苦参碱重定位及作用机制研究——以多发性硬化症为例

目的为探索氧化苦参碱(oxymatrine,OMAT)新的潜在应用价值,采用生物信息学技术对OMAT的药理作用重定位,通过动物实验验证并探索潜在作用机制。方法基于GEO数据库,筛选OMAT调控的差异表达基因(differentially expressed genes,DEGs),并导入CMap与Coexpedia数据库对OMAT药理作用及适应症重定位,选取代表性适应症对应靶点基因与DEGs取交集,构建靶点基因的蛋白互作网络,进行GO与KEGG功能富集分析,最后通过动物实验进行验证。结果筛选出619个OMAT调控的DEGs。重定位结果表明,OMAT或可用于治疗多发性硬化症(multiple sclerosis,MS)、关节炎等疾病。以MS为例进行后续分析,GO与KEGG结果提示,OMAT可能通过调控ERK的生物过程与Ras和钙离子等信号通路发挥治疗MS作用。动物实验结果表明,与模型组相比,OMAT治疗组神经功能评分明显降低,中枢神经炎症浸润和髓鞘脱失程度也明显减轻。RT-PCR结果显示,OMAT明显降低模型组小鼠Fgfr2、Rras2、Raf1、Camk2a、Calm1的mRNA表达水平,明显上调Fgf2的mRNA表达水平。结论OMAT对MS有治疗作用,其机制可能与调控Fgf2、IL4、ICAM1、Fgfr2等靶点,抑制Ras信号通路和钙离子信号通路的关键靶点有关。本研究扩大了OMAT的应用范围,也为其他药物的再开发提供借鉴。

火把花根片对实验性自身免疫性脑脊髓炎大鼠脑IL-2和IFN-γ mRNA的影响

目的:探讨火把花根片对实验性自身免疫性脑脊髓炎(EAE)Wistar大鼠的治疗作用及IL-2和IFN-γmRNA的影响。方法:模型组采用豚鼠髓鞘蛋白匀浆和福氏完全佐剂诱发大鼠急性EAE;治疗组在模型组基础上予以火把花根片(300 mg.kg-1,BID)治疗,观察症状并评分;HE染色和Loyez氏髓鞘染色,观察病理和髓鞘改变;RT-PCR法测定脑组织的IL-2和IFN-γ的mRNA表达水平。结果:治疗组未出现EAE症状,脑组织IL-2和IFN-γ的mRNA表达水平分别为0.345±0.032、0.353±0.023,与模型组比较P<0.01;脑和脊髓小血管周围炎症细胞浸润明显减少;髓鞘结构完整。结论:火把花根片对EAE有治疗作用,其机制与抑制了脑组织IL-2和IFR-γ的mRNA表达有关。

多发性硬化药物研发中动物模型研究进展及应用

多发性硬化(multiple sclerosis,MS)是一种由免疫介导的中枢神经系统(central nervous system,CNS)慢性炎症性疾病,受多种病理生理机制调控。MS临床表型主要包括复发缓解型(relapsing-remitting MS,RRMS)、原发性进展型(primary progressive MS,PPMS)、继发性进展型(secondary-progressive MS,SPMS)和进行性复发型(progressive relapsing MS,PRMS)四种类型,其中以RRMS最为常见。MS发病原因不明,不能治愈,患者需接受长期治疗。动物模型的应用在MS防治药物的临床前研究中发挥了重要作用。目前,用于研究MS的动物模型主要分为实验性自身免疫性脑脊髓炎(experimental autoimmune encephalomyelitis,EAE)模型、毒素诱导的脱髓鞘模型和病毒诱导的脱髓鞘模型三种,以EAE模型应用最为广泛。三种动物模型又因其诱导方式和动物种类的不同呈现不同的特点,并对应MS的不同临床分型。研究人员针对其特定的临床分型,采用合适的动物模型进行药物研发,将有助于开发出更具针对性和潜力的治疗药物,使MS治愈成为可能。

复方中药制剂对实验性自身免疫性脑脊髓炎小鼠神经保护作用的研究

目的探讨自制复方中药制剂对实验性自身免疫性脑脊髓炎(EAE)小鼠的疗效及相关机制。方法选取SPF级雌性C57BL/6小鼠36只,采用皮下注射MOG_(35-55)抗原免疫诱导EAE模型。将36只小鼠随机分为EAE模型组、中药组和激素组,每组各12只。自造模第14天起,中药组按体重20 g/kg给予自制复方中药灌胃,激素组按体重3.9 mg/kg给予醋酸泼尼松灌胃治疗,EAE模型组按同样方法给予等量生理盐水,至造模第42天结束。采用Kono 5级评分法评估各组小鼠神经功能,采用HE染色法观察中枢神经系统(CNS)炎细胞浸润,采用LFB染色法观察CNS脱髓鞘情况,采用酶联免疫吸附法检测外周血γ干扰素(IFN-γ)、白细胞介素-4(IL-4)和IL-17A细胞因子水平,采用Western blot检测CNS组织血清/糖皮质激素诱导激酶-1(serum/glucocorticoid-inducible kinase-1,SGK-1)表达。结果中药组小鼠神经功能评分峰值低于EAE模型组(P<0.01),脑脊髓组织炎细胞浸润和脱髓鞘程度较EAE模型组减轻。与EAE模型组比较,中药组EAE小鼠EAE病程前期、高峰期以及缓解期外周血IFN-γ和IL-17A水平均低(均P<0.01),而IL-4水平均高(均P<0.01);与激素组比较,中药组小鼠不同EAE病程阶段IFN-γ和IL-4水平比较均无统计学差异(均P>0.05),而IL-17A水平于EAE高峰期和缓解期低于激素组(均P<0.05)。中药组小鼠脑脊髓组织SGK-1蛋白表达在病程高峰期及缓解期均低于EAE模型组和激素组(均P<0.01)。结论该复方中药制剂对EAE小鼠具有神经保护作用,可减轻EAE小鼠临床症状及CNS组织炎性浸润及脱髓鞘,其作用机制可能与通过SGK-1蛋白调节细胞因子水平有关。