Exposure to ALS-FTD-CSF generates TDP-43 aggregates in glioblastoma cells through exosomes and TNTs-like structure.
Exposure to ALS-FTD-CSF generates TDP-43 aggregates in glioblastoma cells through exosomes and TNTs-like structure.
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暴露于 ALS-FTD-CSF 会通过外泌体和 TNT 样结构在胶质母细胞瘤细胞中产生 TDP-43 聚集体。
DOI：
10.18632/oncotarget.4680
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发表时间：
2015-09-15
期刊：
影响因子：
--
通讯作者：
Wang X
中科院分区：
文献类型：
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作者：
Ding X;Ma M;Teng J;Teng RK;Zhou S;Yin J;Fonkem E;Huang JH;Wu E;Wang X
肌萎缩侧索硬化症(ALS)和额颞叶痴呆(FTD)是一系列破坏性的神经退行性疾病，其特征是43 kDa的反式反应DNA结合蛋白(TDP-43)聚集在整个神经系统。尽管迅速出现的证据表明，在ALS症状的区域性传播中存在TDP-43阳性包涵体的普恩病毒样传播假说，但TDP-43聚集体是否以及如何在细胞之间传播尚不清楚。在此，我们建立了一个脑脊液(CSF)培养的细胞模型来分析TDP-43聚集体的形成和增殖机制。值得注意的是，ALS-FTD-CSF作用于人脑胶质瘤U251细胞21天后，细胞内TDP-43错误定位和聚集，而ALS-CSF和正常对照(NC)-CSF则未见。ALS-FTD-CSF来源的外体富含TDP-43C末端片段(CTF)。ALS-FTD-CSF可诱导U251细胞TDP-43错位阳性外切体增多。我们进一步证明，暴露于ALS-FTD-CSF可以在不同的阶段诱导产生类似隧道纳米管(TNTs)的结构和外切体，这介导了TDP-43聚集体在培养的U251细胞中的增殖。此外，免疫印迹分析显示，ALS-CSF和ALS-FTD-CSF孵育后，U251细胞出现异常的细胞凋亡和自噬激活。综上所述，我们的数据提供了ALS-FTD-CSF具有类似Pron的可传播特性的直接证据。TNTs样结构和外切体为TDP-43聚集体的转移提供了途径，选择性地抑制它们的过度世代可能会阻断TDP-43蛋白病变的进展。
Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) represent a continuum of devastating neurodegenerative diseases, characterized by transactive response DNA-binding protein of 43 kDa (TDP-43) aggregates accumulation throughout the nervous system. Despite rapidly emerging evidence suggesting the hypothesis of ‘prion-like propagation’ of TDP-43 positive inclusion in the regional spread of ALS symptoms, whether and how TDP-43 aggregates spread between cells is not clear. Herein, we established a cerebrospinal fluid (CSF)-cultured cell model to dissect mechanisms governing TDP-43 aggregates formation and propagation. Remarkably, intracellular TDP-43 mislocalization and aggregates were induced in the human glioma U251 cells following exposure to ALS-FTD-CSF but not ALS-CSF and normal control (NC) -CSF for 21 days. The exosomes derived from ALS-FTD-CSF were enriched in TDP-43 C-terminal fragments (CTFs). Incubation of ALS-FTD-CSF induced the increase of mislocated TDP-43 positive exosomes in U251 cells. We further demonstrated that exposure to ALS-FTD-CSF induced the generations of tunneling nanotubes (TNTs)-like structure and exosomes at different stages, which mediated the propagation of TDP-43 aggregates in the cultured U251 cells. Moreover, immunoblotting analyses revealed that abnormal activations of apoptosis and autophagy were induced in U251 cells, following incubation of ALS-CSF and ALS-FTD-CSF. Taken together, our data provide direct evidence that ALS-FTD-CSF has prion-like transmissible properties. TNTs-like structure and exosomes supply the routes for the transfer of TDP-43 aggregates, and selective inhibition of their over-generations may interrupt the progression of TDP-43 proteinopathy.