Elucidating the Pathogenic Mechanisms of VPS35 Mutations in Parkinson's Disease

项目总结 线粒体功能障碍在帕金森病(PD)的发病机制中起着重要作用。 线粒体是动态细胞器，经历着持续的分裂和融合事件，这对 生理功能。越来越多的证据显示帕金森病和帕金森病患者线粒体动力学异常 模型，提示线粒体分裂/融合的平衡改变和线粒体质量受损 控制可能是导致线粒体和神经元功能障碍/变性的常见机制 在帕金森病的发病机制中起关键作用。VPS35基因突变导致常染色体显性遗传性帕金森病。VPS35是一把钥匙 逆转聚体复合体的组成部分，它对内体到高尔基体和内体到血浆是重要的 膜分选和许多信号事件。最近的研究发现VPS35在线粒体上的定位 以及参与线粒体和其他细胞器之间的细胞器间通讯。在我们的 初步研究，我们证实了VPS35在两种人神经母细胞瘤细胞中的线粒体定位 以及人脑海马神经元。我们进一步发现，野生型VPS35在神经元中的过度表达 引起线粒体动力学的显著变化，在表达PD-1的神经元中变得更加严重 相关VPS35突变体D620N。更重要的是，我们发现VPS35与DLP1在物理上相互作用， 线粒体动力学的关键调节因子，这是由PD相关突变增强的。所有这些令人兴奋的事情 研究结果有力地表明，VPS35参与了线粒体动力学的调节，这可能是 VPS35 PD相关突变受损及PS1在脑出血中的潜在作用 线粒体的功能和动力学是有保证的。我们提议的研究将是第一个机械学研究 探讨致病性VPS35 PD突变对线粒体动力学和功能的影响 神经功能，并可能揭示VPS35在线粒体调节中的新作用 动力学/功能。此外，我们建议的研究还将为以下贡献提供新的见解 逆转录到各种细胞过程和信号通路。

PROJECT SUMMARY Mitochondrial dysfunction plays a prominent role in the pathogenesis of Parkinson's disease (PD). Mitochondria are dynamics organelles that undergo continual fission and fusion events which serve crucial physiological function. Increasing evidence demonstrated abnormal mitochondrial dynamics in PD and PD models, suggesting that an altered balance in mitochondrial fission/fusion and impaired mitochondrial quality control was likely a common mechanism leading to mitochondrial and neuronal dysfunction/degeneration critical to the pathogenesis of PD. Mutations in VPS35 cause autosomal dominant PD. VPS35 is a key component of the retromer complex, which is be important for endosome-to-golgi and endosome-to-plasma membrane sorting and many signaling events. Recent studies found the localization of VPS35 on mitochondria and its involvement in inter-organelle communication between mitochondria and other organelles. In our preliminary studies, we confirmed the mitochondrial localization of VPS35 in both human neuroblastoma cells and human brain hippocampal neurons. We further found that overexpression of wild-type VPS35 in neurons caused significant changes of mitochondrial dynamics, which became more severe in neurons expressing PD- associated VPS35 mutant D620N. More importantly, we found that VPS35 physically interacted with DLP1, a key regulator of mitochondrial dynamics, which was enhanced by PD-associated mutation. All these exciting findings strongly suggest that VPS35 were involved in the regulation of mitochondrial dynamics which may be impaired by VPS35 PD associated mutations and detailed investigation into the potential role of PS1 in mitochondrial function and dynamics is warranted. Our proposed study will be the first mechanistic study investigating the effect of the pathogenic VPS35 PD mutations on mitochondrial dynamics/function and neuronal function and will likely reveal a novel role of VPS35 in the regulation of mitochondrial dynamics/function. In addition, our proposed studies will also provide novel insights into the contribution of retromer to various cellular processes and signaling pathways.