Proteopathic brain lesions are a hallmark of many age-related neurodegenerative diseases including synucleinopathies and develop at least a decade before the onset of clinical symptoms. Thus, understanding of the initiation and propagation of such lesions is key for developing therapeutics to delay or halt disease progression. Alpha-synuclein (αS) inclusions were induced in long-term murine and human slice cultures by seeded aggregation. An αS seed-recognizing human antibody was tested for blocking seeding and/or spreading of the αS lesions. Release of neurofilament light chain (NfL) into the culture medium was assessed. To study initial stages of α-synucleinopathies, we induced αS inclusions in murine hippocampal slice cultures by seeded aggregation. Induction of αS inclusions in neurons was apparent as early as 1week post-seeding, followed by the occurrence of microglial inclusions in vicinity of the neuronal lesions at 2–3 weeks. The amount of αS inclusions was dependent on the type of αS seed and on the culture’s genetic background (wildtype vs A53T-αS genotype). Formation of αS inclusions could be monitored by neurofilament light chain protein release into the culture medium, a fluid biomarker of neurodegeneration commonly used in clinical settings. Local microinjection of αS seeds resulted in spreading of αS inclusions to neuronally connected hippocampal subregions, and seeding and spreading could be inhibited by an αS seed-recognizing human antibody. We then applied parameters of the murine cultures to surgical resection-derived adult human long-term neocortical slice cultures from 22 to 61-year-old donors. Similarly, in these human slice cultures, proof-of-principle induction of αS lesions was achieved at 1week post-seeding in combination with viral A53T-αS expressions. The successful translation of these brain cultures from mouse to human with the first reported induction of human αS lesions in a true adult human brain environment underlines the potential of this model to study proteopathic lesions in intact mouse and now even aged human brain environments.

中文翻译：

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在长期脑切片培养中，神经元 α-突触核蛋白损伤后小胶质细胞内含物和神经丝轻链释放

蛋白病性脑损伤是许多与年龄相关的神经退行性疾病（包括突触核蛋白病）的标志，并且至少在临床症状出现前十年就已发生。因此，了解此类病变的发生和传播是开发延迟或阻止疾病进展的治疗方法的关键。α-突触核蛋白 (αS) 内含物是通过种子聚集在长期小鼠和人类切片培养物中诱导产生的。测试了 αS 种子识别人类抗体，以阻止 αS 病变的播种和/或扩散。评估了神经丝轻链（NfL）释放到培养基中的情况。为了研究 α-突触核蛋白病的初始阶段，我们通过种子聚集在小鼠海马切片培养物中诱导 αS 内含物。早在接种后 1 周，神经元中 αS 内含物的诱导就很明显，随后 2-3 周，神经元损伤附近出现小胶质细胞内含物。αS 内含物的量取决于 αS 种子的类型和培养物的遗传背景（野生型与 A53T-αS 基因型）。αS 内含物的形成可以通过神经丝轻链蛋白释放到培养基中来监测，神经丝轻链蛋白是临床环境中常用的神经退行性变的液体生物标志物。αS 种子的局部显微注射导致 αS 内含物扩散到神经元连接的海马亚区域，并且可识别 αS 种子的人类抗体可以抑制播种和扩散。然后，我们将小鼠培养物的参数应用于手术切除的 22 至 61 岁捐赠者的成人长期新皮质切片培养物。同样，在这些人类切片培养物中，在接种后 1 周结合病毒 A53T-αS 表达实现了 αS 损伤诱导的原理验证。这些大脑培养物从小鼠到人类的成功转化，首次报道了在真正的成人大脑环境中诱导人类 αS 损伤，这突显了该模型在完整小鼠甚至现在老年人类大脑环境中研究蛋白病损伤的潜力。