Fernandez Bessone Iván, Navarro Jordi, Martinez Emanuel, Karmirian Karina, Holubiec Mariana, Alloatti Matias, Goto-Silva Livia, Arnaiz Yepez Cayetana, Martins-de-Souza Daniel, Minardi Nascimento Juliana, Bruno Luciana, Saez Trinidad M, Rehen Stevens K, Falzone Tomás L
Instituto de Biología Celular y Neurociencia IBCN, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina C1121ABG.
D'Or Institute for Research and Education, Rio de Janeiro, Brasil, RJ, 22281-100.
J Neurosci. 2022 Aug 17;42(33):6344-6358. doi: 10.1523/JNEUROSCI.2551-21.2022.
triplication in Down's syndrome and its overexpression in Alzheimer's disease suggest a role for increased DYRK1A activity in the abnormal metabolism of APP. Transport defects are early phenotypes in the progression of Alzheimer's disease, which lead to APP processing impairments. However, whether DYRK1A regulates the intracellular transport and delivery of APP in human neurons remains unknown. From a proteomic dataset of human cerebral organoids treated with harmine, a DYRK1A inhibitor, we found expression changes in protein clusters associated with the control of microtubule-based transport and in close interaction with the APP vesicle. Live imaging of APP axonal transport in human-derived neurons treated with harmine or overexpressing a dominant negative DYRK1A revealed a reduction in APP vesicle density and enhanced the stochastic behavior of retrograde vesicle transport. Moreover, harmine increased the fraction of slow segmental velocities and changed speed transitions supporting a DYRK1A-mediated effect in the exchange of active motor configuration. Contrarily, the overexpression of DYRK1A in human polarized neurons increased the axonal density of APP vesicles and enhanced the processivity of retrograde APP. In addition, increased DYRK1A activity induced faster retrograde segmental velocities together with significant changes in slow to fast anterograde and retrograde speed transitions, suggesting the facilitation of the active motor configuration. Our results highlight DYRK1A as a modulator of the axonal transport machinery driving APP intracellular distribution in neurons, and stress DYRK1A inhibition as a putative therapeutic intervention to restore APP axonal transport in Down's syndrome and Alzheimer's disease. Axonal transport defects are early events in the progression of neurodegenerative diseases, such as Alzheimer's disease. However, the molecular mechanisms underlying transport defects remain elusive. kinase is triplicated in Down's syndrome and overexpressed in Alzheimer's disease, suggesting that DYRK1A dysfunction affects molecular pathways leading to early-onset neurodegeneration. Here, we show by live imaging of human-derived neurons that DYRK1A activity differentially regulates the intracellular trafficking of APP. Further, single-particle analysis revealed DYRK1A as a modulator of axonal transport and the configuration of active motors within the APP vesicle. Our work highlights DYRK1A as a regulator of APP axonal transport and metabolism, supporting DYRK1A inhibition as a therapeutic strategy to restore intracellular dynamics in Alzheimer's disease.
唐氏综合征中的三倍体现象以及其在阿尔茨海默病中的过表达表明，DYRK1A活性增加在淀粉样前体蛋白（APP）的异常代谢中发挥作用。转运缺陷是阿尔茨海默病进展过程中的早期表型，会导致APP加工受损。然而，DYRK1A是否调节人类神经元中APP的细胞内转运和递送仍不清楚。从用双氢骆驼蓬碱（一种DYRK1A抑制剂）处理的人类大脑类器官的蛋白质组数据集中，我们发现与基于微管的转运控制相关且与APP囊泡密切相互作用的蛋白质簇的表达发生了变化。在用双氢骆驼蓬碱处理或过表达显性负性DYRK1A的人类来源神经元中对APP轴突转运进行实时成像，结果显示APP囊泡密度降低，并增强了逆行囊泡转运的随机行为。此外，双氢骆驼蓬碱增加了慢速节段速度的比例，并改变了速度转换，支持DYRK1A在活性运动构型交换中的介导作用。相反，在人类极化神经元中过表达DYRK1A会增加APP囊泡的轴突密度，并增强逆行APP的持续性。此外，DYRK1A活性增加会诱导更快的逆行节段速度，同时在慢速到快速的顺行和逆行速度转换中发生显著变化，表明促进了活性运动构型。我们的结果突出了DYRK1A作为驱动神经元中APP细胞内分布的轴突转运机制的调节因子，并强调抑制DYRK1A作为一种可能的治疗干预措施，以恢复唐氏综合征和阿尔茨海默病中APP轴突转运。轴突转运缺陷是神经退行性疾病（如阿尔茨海默病）进展过程中的早期事件。然而，转运缺陷背后的分子机制仍然难以捉摸。DYRK1A激酶在唐氏综合征中存在三倍体现象且在阿尔茨海默病中过表达，这表明DYRK1A功能障碍会影响导致早发性神经退行性变的分子途径。在这里，我们通过对人类来源神经元的实时成像表明，DYRK1A活性差异调节APP的细胞内运输过程。此外，单颗粒分析显示DYRK1A是轴突转运以及APP囊泡内活性运动构型的调节因子。我们的工作突出了DYRK1A作为APP轴突运输和代谢的调节因子，支持将抑制DYRK1A作为一种治疗策略来恢复阿尔茨海默病中的细胞内动力学。
