Neuronal Deficiency of Cytochrome c Oxidase Engineered by Mitochondrial DNA Editing Recapitulates Amyotrophic Lateral Sclerosis [snRNA-seq]

Amyotrophic lateral sclerosis (ALS) is categorized into 10% familial and 90% sporadic cases. While the space of 10% familial ALS is crowded with mutations in many genes of diverse functions, most ALS-associated mutations could not faithfully recapitulate the disease phenotype in animal models. Remarkably, nearly half of sporadic ALS patients exhibit defective mitochondrial respiratory complex â…£ (Câ…£). To establish the causal role of defective Câ…£ in inducing ALS, we employed TALE-based mtDNA editing to mimic ALS-linked mutations in Câ…£ compared to other respiratory complexes in rat neurons and demonstrated that mutations exclusively introduced to mtDNA-encoded Câ…£ subunits are sufficient to cause a full spectrum of ALS-like phenotypes, including selective motor neuron loss, SOD1 overexpression and cytosolic TDP-43 aggregation. These findings reveal a broad basis for sporadic ALS, provide critical insights into the selective motor neuron vulnerability, and present a faithful animal model for advancing ALS therapy.肌萎缩侧索硬化症（Amyotrophic lateral sclerosis, ALS）可分为10%的家族性病例与90%的散发性病例。尽管10%的家族性ALS患者已在多种功能各异的基因中发现致病突变，但绝大多数与ALS相关的突变无法在动物模型中忠实重现疾病表型。值得注意的是，近半数散发性ALS患者存在线粒体呼吸链复合物Ⅳ（mitochondrial respiratory complex Ⅳ, CⅣ）功能缺陷。为明确CⅣ功能缺陷在ALS发病中的因果作用，我们采用基于转录激活样效应因子（Transcription Activator-Like Effector, TALE）的线粒体DNA编辑技术，在大鼠神经元中模拟ALS相关的CⅣ突变，并与其他呼吸链复合物突变进行对照。实验证实，仅对线粒体DNA编码的CⅣ亚基引入突变，即可引发全套类ALS表型，包括选择性运动神经元丢失、超氧化物歧化酶1（Superoxide Dismutase 1, SOD1）过表达以及胞浆内TDP-43聚集。本研究结果揭示了散发性ALS的广泛发病基础，为理解运动神经元的选择性易损性提供了关键见解，同时也为推动ALS治疗研究提供了可靠的动物模型。