少突胶质细胞连接蛋白研究:Cx32与突变型或野生型Cx47组成的异型通道不影响缝隙连接功能  

Investigating oligodendrocyte connexins:Heteromeric interactions between Cx32 and mutant or wild-type forms of Cx47 do not contribute to or modulate gap junction function

作　　者：Charles K Abrams Rafael E Flores-Obando Gabriel D Dungan Elina Cherepanova Mona M Freidin 唐颖馨(编译) Charles K Abrams;Rafael E Flores-Obando;Gabriel D Dungan;Elina Cherepanova;Mona M Freidin(Department of Neurology and Rehabilitation,University of Illinois at Chicago College of Medicine,Chicago,Illinois,USA;Department of Neurology,SUNY Downstate Medical Center,Brooklyn,New York,USA)

机构地区：[1]Department of Neurology and Rehabilitation,University of Illinois at Chicago College of Medicine,Chicago,Illinois,USA [2]Department of Neurology,SUNY Downstate Medical Center,Brooklyn,New York,USA [3]不详

出　　处：《神经损伤与功能重建》2021年第4期F0003-F0003,共1页Neural Injury and Functional Reconstruction

摘　　要：少突胶质细胞上表达有两种缝隙连接蛋白,连接蛋白32(Cx32)和Cx47。因此,可能会形成由Cx47和Cx32两种单体组成的异型通道。Cx47突变会导致Pelizaeus-Merzbacer样疾病1型(PMLD1)和遗传性痉挛性轻瘫44型(SPG44)。Cx47突变体之间或与Cx32之间形成的异型通道可能是这些疾病的发病机理之一。本研究将利用电生理学和抗体相关研究方法来检验这些可能的机制。当同时表达Cx32和Cx47的细胞与表达Cx32或Cx47的细胞配对组成异型通道时,其特性与由Cx32或Cx47组成的同型通道无差别。同样的,将同时表达Cx32和Cx47的细胞与表达Cx30或Cx43的细胞配对产生的通道的特性与异型通道Cx32/Cx30或Cx47/Cx43没有区别。本研究对表达Cx32和4种突变形式的Cx47(与SPG44或p.P87S相关的p.I33M,与PMLD1相关的p.Y269D或p.M283T)的细胞进行了评估,结果显示这些突变体均未对Cx32的功能产生影响。共表达Cx32WT(野生型)和Cx47WT的免疫染色细胞显示Pearson相关系数接近零,表明任何重叠都是由于偶然。统计分析显示,p.Y269D与Cx32显著负相关,表明Cx32与该突变体的重叠低于随机的可能性。Cx32和Cx47WT及其突变体的免疫共沉淀仅显示极低水平的免疫共沉淀蛋白。综上所述,本研究结果显示,PMLD1或SPG44突变体与Cx32缝隙连接之间的相互作用不会导致这些疾病的发生。Oligodendrocytes express two gap junction forming connexins,connexin 32(Cx32)and Cx47;therefore,formation of heteromeric channels containing both Cx47 and Cx32 monomers might occur.Mutations in Cx47 cause both Pelizaeus-Merzbacher-like disease Type 1(PMLD1)and hereditary spastic paraparesis Type 44(SPG44)and heteromer formation between these mutants and Cx32 may contribute to the pathogenesis of these disorders.Here,we utilized electrophysiological and antibody-based techniques to examine this possibility.When cells expressing both Cx32 and Cx47 were paired with cells expressing either Cx32 or Cx47,properties were indistinguishable from those produced by cells expressing homotypic Cx32 or Cx47 channels.Similarly,pairing cells expressing both Cx32 and Cx47 with cells expressing Cx30 or Cx43 produced channels indistinguishable from heterotypic Cx32/Cx30 or Cx47/Cx43 channels,respectively.The same assessments were performed on cells expressing Cx32 and four mutant forms of Cx47(p.I33 M associated with SPG44 or p.P87 S,p.Y269 D or p.M283 T associated with PMLD1).None of these mutants showed a functional effect on Cx32.Immunostained cells co-expressing Cx32 WT(wild type)and Cx47 WT showed a Pearson correlation coefficient close to zero,suggesting that any overlap was due to chance.p.Y269 D showed a statistically significant negative correlation with Cx32,suggesting that Cx32 and this mutant overlap less than expected by chance.Co-immunoprecipitation of Cx32 with Cx47 WT and mutants show only very low levels of co-immunoprecipitated protein.Overall,our data suggest that interactions between PMLD1 or SPG44 mutants and Cx32 gap junctions do not contribute to the pathogenesis of these disorders.

关 键 词：连接蛋白32 连接蛋白47 Pelizaeus-Merzbacer样病1型 缝隙连接 脑白质营养不良 

分 类 号：R741[医药卫生—神经病学与精神病学] R741.02[医药卫生—临床医学]