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开发脊椎动物模型,突出Nefl和miRNAs在ALS发病机制中的功能相关性

Developing vertebrate models to highlight the functional relevance of Nefl and miRNAs in ALS pathogenesis
课程网址: http://videolectures.net/encals2017_demy_vertebrate_models/  
主讲教师: Doris Lou Demy
开课单位: 巴斯德研究所
开课时间: 2017-07-21
课程语种: 英语
中文简介:
包括TDP-43、FUS和ATXN2在内的一系列与ALS发病相关的基因编码在RNA代谢中起作用的蛋白质。此外,初步结果表明,miRNAs在脊髓运动神经元中异常表达,编码神经丝蛋白的mRNAs是疾病相关靶点,是ALS患者最可靠的预后生物标志物。为了解决涉及的机制并确定常见的治疗靶点,我们开发了斑马鱼模型,该模型允许大规模药物筛选和生物过程的体内评估,并结合广泛的遗传工具:基因过度表达(DNA或RNA注射),敲除(反义吗啉注射)或敲除(CRISPR/Cas9和缺失突变体),以确定体内miRNA和神经丝蛋白的功能,以及其破坏的后果。我们鉴定和鉴定了低分子量神经丝蛋白(Nefl)的斑马鱼同系物,并评估了其在生理和ALS病理条件下的表达。我们还确定,使用反义寡核苷酸下调斑马鱼中特定的Nefl亚型会导致强烈的ALS样运动表型(运动轴突萎缩合并瘫痪,反映为诱发游泳反应的缺陷)。我们目前正在使用CRISPR/Cas9基因组编辑工具开发长期Nefl-KO,并从携带Nefl直系同源突变的EZRC获得斑马鱼系。我们还通过Western Blot对ALS斑马鱼模型中Nefl的表达进行了评估,发现TDP43基因敲除导致Nefl蛋白的显著降低。我们的合作者,Drs.Strong和Hornstein在体外鉴定了影响Nefl表达和聚集的特异性miRNA,并且已知在ALS患者中异常表达。同时,我们正在对斑马鱼胚胎中的这些miRNA进行下调,以评估它们的生物学后果。对其中两个miRNA的抑制导致活斑马鱼仔鱼运动神经元的运动缺陷和轴突投射的异常分支,与Nefl表达的强烈中断相关。这些动物模型将使我们能够阐明这些关键因素在ALS发病机制中的作用,并将为今后的研究提供相关终点,以确定ALS的新治疗靶点。ERA-NET E-rare(ANR)项目RNA-ALS和ERC项目ALS网络提供的资金。
课程简介: A striking number of genes, including TDP-43, FUS and ATXN2 implicated in ALS pathogenesis encode proteins with functions in RNA metabolism. Also, preliminary results suggest that miRNAs are aberrantly expressed in spinal motor neurons, and that mRNAs encoding neurofilament proteins are a disease relevant target and represent the most reliable prognostic biomarker for ALS patients. To address the mechanisms involved and identify common therapeutic targets, we developed zebrafish models, which allows large-scale drug screening and in vivo assessment of biological processes, combined with a wide range of genetic tools: gene overexpression (DNA or RNA injection), knock-down (antisense morpholino injection) or knock out (CRISPR/Cas9 and deletion mutants) to define in vivo the functions of miRNAs and neurofilament proteins, as well as the consequences of their disruption. We identified and characterized the zebrafish homologues for the low molecular weight neurofilament protein (Nefl) and assessed its expression within physiological and ALS pathological conditions. We also established that down regulation of a specific Nefl isoform in zebrafish using antisense oligonucleotides results in a strong ALS-like motor phenotype (motor axon atrophy combined to a paralysis reflected by deficits in the evoked swimming response). We are currently developing long-term Nefl KO using the CRISPR/Cas9 genome editing tools and obtained zebrafish lines from EZRC carrying mutations in the Nefl orthologues. We also assessed by Western Blot the expression of Nefl within ALS zebrafish models, and revealed that TDP43 knock- down leads to a strong decrease in Nefl protein. Our collaborators, Drs. Strong and Hornstein identified specific miRNAs that affect Nefl expression and aggregation in vitro and are known to be aberrantly expressed in ALS patients. In parallel, we are performing down regulations of these miRNAs of interest in zebrafish embryos to assess their biological consequences. Inhibition of two of these miRNAs led to motor deficits and aberrant branching of axonal projections from motor neurons in live zebrafish larvae, associated with a strong disruption of Nefl expression. These animal models will allow us to elucidate the role of these key actors in ALS pathogenesis and will provide relevant endpoints for future studies to identify novel therapeutics targets for ALS. Funding provided by the ERA-NET E-rare (ANR) project RNA-ALS and the ERC project ALS-Networks.
关 键 词: 脊髓运动神经元; ALS; 治疗靶点
课程来源: 视频讲座网
数据采集: 2021-12-24:zkj
最后编审: 2021-12-24:zkj
阅读次数: 67