Axonal pathology in hPSC-based models of Parkinson's disease results from loss of Nrf2 transcriptional activity at the Map1b gene locus
Axonal pathology in hPSC-based models of Parkinson's disease results from loss of Nrf2 transcriptional activity at the Map1b gene locus
复制标题
DOI：
10.1073/pnas.1900576116
复制
发表时间：
2019-07-09
影响因子：
11.1
通讯作者：
Ryan, Scott D.
中科院分区：
文献类型：
--
作者：
Czaniecki, Christopher;Ryan, Tammy;Ryan, Scott D.
虽然SNCA基因（α-突触核蛋白[α-syn]）的突变在罕见的帕金森病（PD）家族形式中是因果关系，但散发性疾病病例皮质中α-syn聚集体的流行强调了理解α-syn积累与疾病发病机制之间联系的必要性。通过采用与同基因对照相比具有SNCA-A53 T突变的人多能干细胞（hPSC）的组合，我们评估了人A9型多巴胺能（DA）神经元（hN）中α-syn积累的后果。我们表明，SNCA-A53 T hNs中α-syn的早期积累导致基因表达的变化，与PD患者的黑质（SN）的表达谱一致，死后分析。来自PD患者SN和SNCA-A53 T hNs的差异表达基因与由抗氧化反应途径转录激活的调控基序相关，特别是Nrf 2基因靶点。差异表达的基因靶标也富集了与微管结合过程相关的基因本体。因此，我们评估了SNCA-A53 T hNs中Nrf 2介导的基因表达与神经炎病理学之间的关系。我们发现，SNCA突变hNs有赤字的神经炎的长度和复杂性相对于同基因对照，以及扭曲的轴突与Tau阳性静脉曲张。此外，我们发现突变体α-syn未能与蛋白激酶C（PKC）复合，这反过来又导致Nrf 2的激活受损。这些神经炎性缺陷是由于Nrf 2对定位于微管相关蛋白（Map 1b）基因增强子的抗氧化反应元件（战神）的活性受损所致，并通过Map 1b的强制表达以及Nrf 2过表达和PD神经元中的药物活化来拯救。
While mutations in the SNCA gene (alpha-synuclein [alpha-syn]) are causal in rare familial forms of Parkinson's disease (PD), the prevalence of alpha-syn aggregates in the cortices of sporadic disease cases emphasizes the need to understand the link between alpha-syn accumulation and disease pathogenesis. By employing a combination of human pluripotent stem cells (hPSCs) that harbor the SNCA-A53T mutation contrasted against isogenic controls, we evaluated the consequences of alpha-syn accumulation in human A9-type dopaminergic (DA) neurons (hNs). We show that the early accumulation of alpha-syn in SNCA-A53T hNs results in changes in gene expression consistent with the expression profile of the substantia nigra (SN) from PD patients, analyzed post mortem. Differentially expressed genes from both PD patient SN and SNCA-A53T hNs were associated with regulatory motifs transcriptionally activated by the antioxidant response pathway, particularly Nrf2 gene targets. Differentially expressed gene targets were also enriched for gene ontologies related to microtubule binding processes. We thus assessed the relationship between Nrf2-mediated gene expression and neuritic pathology in SNCA-A53T hNs. We show that SNCA-mutant hNs have deficits in neuritic length and complexity relative to isogenic controls as well as contorted axons with Tau-positive varicosities. Furthermore, we show that mutant alpha-syn fails to complex with protein kinase C (PKC), which, in turn, results in impaired activation of Nrf2. These neuritic defects result from impaired Nrf2 activity on antioxidant response elements (AREs) localized to a microtubule-associated protein (Map1b) gene enhancer and are rescued by forced expression of Map1b as well as by both Nrf2 overexpression and pharmaceutical activation in PD neurons.