Gómez-Deza Jorge, Nebiyou Matthew, Alkaslasi Mor R, Nadal-Nicolás Francisco M, Somasundaram Preethi, Slavutsky Anastasia L, Li Wei, Ward Michael E, Watkins Trent A, Le Pichon Claire E
Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA.
National Eye Institute, National Institutes of Health, Bethesda, MD, USA.
Nat Commun. 2024 Dec 30;15(1):10806. doi: 10.1038/s41467-024-54982-9.
Currently there are no effective treatments for an array of neurodegenerative disorders to a large part because cell-based models fail to recapitulate disease. Here we develop a reproducible human iPSC-based model where laser axotomy causes retrograde axon degeneration leading to neuronal cell death. Time-lapse confocal imaging revealed that damage triggers an apoptotic wave of mitochondrial fission proceeding from the site of injury to the soma. We demonstrate that this apoptotic wave is locally initiated in the axon by dual leucine zipper kinase (DLK). We find that mitochondrial fission and resultant cell death are entirely dependent on phosphorylation of dynamin related protein 1 (DRP1) downstream of DLK, revealing a mechanism by which DLK can drive apoptosis. Importantly, we show that CRISPR mediated Drp1 depletion protects mouse retinal ganglion neurons from degeneration after optic nerve crush. Our results provide a platform for studying degeneration of human neurons, pinpoint key early events in damage related neural death and provide potential focus for therapeutic intervention.
目前，一系列神经退行性疾病尚无有效的治疗方法，在很大程度上是因为基于细胞的模型无法重现疾病。在此，我们开发了一种可重复的基于人诱导多能干细胞的模型，其中激光轴突切断术会导致逆行性轴突变性，进而导致神经元细胞死亡。延时共聚焦成像显示，损伤会引发线粒体分裂的凋亡波，从损伤部位向胞体推进。我们证明，这种凋亡波是由双亮氨酸拉链激酶（DLK）在轴突中局部启动的。我们发现，线粒体分裂和由此导致的细胞死亡完全依赖于DLK下游的动力相关蛋白1（DRP1）的磷酸化，揭示了DLK驱动细胞凋亡的一种机制。重要的是，我们表明，CRISPR介导的Drp1缺失可保护小鼠视网膜神经节神经元在视神经挤压后免于退变。我们的结果为研究人类神经元的退变提供了一个平台，确定了损伤相关神经死亡中的关键早期事件，并为治疗干预提供了潜在的重点。
