摘要
【目的】探讨过表达miRNA-200a&c后对广州管圆线虫诱导的Balb/c小鼠脱髓鞘性视神经炎的保护作用。【方法】选取2~3周SPF级Balb/c小鼠分成4组,即正常组,广州管圆线虫感染7 d、14 d、21 d组。分别记录不同时间分组小鼠的体质量及其生存情况,并对小鼠进行神经行为学评分及视觉评分。视觉诱发电位(VEP)检测不同时间分组小鼠视觉损伤情况。透射电镜观察不同时间分组小鼠眼球组织结构变化。广州管圆线虫感染第7天时通过立体定位注射向小鼠侧脑室注射miRNA-200a&c外源性类似物,同时将小鼠分为正常组,广州管圆线虫感染21 d组、广州管圆线虫感染+阴性对照(NC)组、广州管圆线虫感染+过表达miRNA-200a&c类似物组。VEP检测以上分组小鼠视觉损伤情况。透射电镜观察以上分组小鼠眼球组织结构变化。免疫荧光检测以上分组小鼠眼部视网膜神经节细胞(RGCs)及视神经少突胶质细胞(OLs)的数量变化。【结果】广州管圆线虫感染第21天,部分Balb/c小鼠眼睑完全闭合(32.52±4.67)%或出现眼球萎缩(15.79±3.23)%等现象,同时出现小鼠体质量下降(21 dpi:P<0.05)和神志不清等表现,感染21 d组小鼠神经行为学评分明显降低,转棒实验时长缩短68%(21 dpi:P<0.01),部分小鼠出现偏瘫而无法正常行走,甚至部分出现行动迟缓、共济失调、定向障碍;另外有部分小鼠出现刺激感觉反应迟钝,单侧视力缺失,视动反应阈值下降83%,视觉功能明显下降(21 dpi:P<0.05)。VEP结果显示广州管圆线虫感染21 d时Balb/c小鼠潜伏期与正常组相比轻度延长(21 dpi:P<0.05),且多为单侧眼部发病。过表达miRNA-200a&c后,与感染21 d组相比,VEP检测结果显示,P1波潜伏期明显缩短(P<0.05);透射电镜结显示视网膜神经节细胞胞质肿胀情况较感染21 d组对比有所减轻,视神经髓鞘结构较感染21 d组对比相对紧密,厚度也较均匀(P<0.05);免疫荧光结果显示RGCs和OLs数量较感染21 d组相比细胞数量明显升高且细胞排列紊乱的现象也有所改善(P<0.05)。【结论】广州管圆线虫感染Balb/c小鼠后引起脱髓鞘性视神经炎,过表达miRNA-200a&c可减轻脱髓鞘性视神经炎造成的损伤,改善小鼠眼部损伤。
【Objective】To investigate the protective effect of overexpressed miRNA-200a&c on Angiostrongylus cantonensis-induced demyelinating optic neuritis in Balb/c mice.【Methods】SPF-grade Balb/c mice(2-3 weeks old)were divided into four groups:a normal group,and three A.cantonensis-infected groups at 7,14,and 21 days post-infection(dpi).Body weight,survival status,neurobehavioral scores,and visual function scores were recorded.Visual evoked potential(VEP)was used to detect visual damage,and transmission electron microscope(TEM)was applied to observe ocular structural changes.On day 7 post-infection,mice were stereotactically injected with exogenous miRNA-200a&c mimics into the lateral ventricle,and then divided into four groups:normal control,A.cantonensis-infected(AC-21 dpi),A.cantonensis-infected+negative control(AC+NC),and A.cantonensis-infected+overexpressed miRNA-200a&c(AC+miRNA-200a&c)mimics.VEP and TEM were repeated to assess visual damage and ocular structural changes.Immunofluorescence was performed to quantify retinal ganglion cells(RGCs)and oligodendrocytes(OLs)in the optic nerve.【Results】At 21 dpi,some mice exhibited complete eyelid closure(32.52±4.67)%or ocular atrophy(15.79±3.23)%,weight loss(P<0.05)and altered consciousness.Neurobehavioral scores significantly decreased(P<0.01),with a 68%decline in rotarod performance;some mice even displayed hemiplegia,slowed movement,ataxia,and directional deficits.Additionally,a subset of mice showed diminished sensory responses,unilateral vision loss(83%reduction in optokinetic threshold),and impaired visual function(P<0.05).VEP results revealed a mild prolongation of latency in infected mice at 21 dpi(P<0.05),predominantly affecting one eye.Following overexpression of miRNA-200a&c,compared with the 21 dpi group,VEP showed significantly shortened P1 latency(P<0.05);TEM showed alleviated cytoplasmic swelling of RGCs,and improved compactness and uniformity of myelin sheath(P<0.05);immunofluorescence showed increased numbers of RGCs and OLs with improved cell alignment(P<0.05).【Conclusions】A.cantonensis infection induces demyelinating optic neuritis in Balb/c mice.Overexpression of miRNA-200a&c alleviates the resulting damage and ameliorates ocular injury.
作者
马芷璇
牛珍
杨亮
吴小杰
吴忠道
冯英
MA Zhixuan;NIU Zhen;YANG Liang;WU Xiaojie;WU Zhongdao;FENG Ying(School of Medicine,South China University of Technology,Guangzhou 510641,China;Department of Parasitology,Zhongshan School of Medicine,Sun Yat-sen University,Guangzhou 510080,China;Key Laboratory of Tropical Diseases Control,Ministry of Education,Guangzhou 510080,China)
出处
《中山大学学报(医学科学版)》
北大核心
2025年第4期619-627,共9页
Journal of Sun Yat-Sen University:Medical Sciences
基金
广州市科技计划项目(202102080053)。
