Glucocerebrosidase reduces the spread of protein aggregation in a Drosophila melanogaster model of neurodegeneration by regulating proteins trafficked by extracellular vesicles.
Glucocerebrosidase reduces the spread of protein aggregation in a Drosophila melanogaster model of neurodegeneration by regulating proteins trafficked by extracellular vesicles.
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葡糖脑苷脂酶通过调节细胞外囊泡运输的蛋白质来减少果蝇神经变性模型中蛋白质聚集的扩散。
DOI：
10.1371/journal.pgen.1008859
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发表时间：
2021-03
期刊：
影响因子：
4.5
通讯作者：
Davis MY
中科院分区：
文献类型：
--
作者：
Jewett KA;Thomas RE;Phan CQ;Lin B;Milstein G;Yu S;Bettcher LF;Neto FC;Djukovic D;Raftery D;Pallanck LJ;Davis MY
神经元内蛋白质异常聚集是帕金森病（PD）的一个重要病理特征。脑蛋白聚集体的扩散与临床疾病进展相关，但其发生机制尚不清楚。编码葡糖脑苷脂酶（GCase）的葡糖苷酶β-酸1（GBA）突变是PD和路易体痴呆最显著的常见遗传风险因素，并与疾病进展加快相关。为了探索GBA突变如何影响发病机制，我们以前创建了一个GBA缺乏症（Gba 1b）的果蝇模型，该模型表现出神经变性和加速蛋白质聚集。Gba 1b突变体的蛋白质组学分析揭示了参与细胞外囊泡（EV）生物学的蛋白质的失调，我们发现Gba 1b突变体的EV的蛋白质组成发生了改变。因此，我们假设GBA可能会影响致病蛋白聚集体通过EV的传播。我们发现，通过在肌肉中异位表达野生型GCase，Gba 1b果蝇的肌肉和脑组织中泛素化蛋白和Ref（2）P（哺乳动物p62的果蝇同源物）的积累减少。神经元GCase表达还拯救了脑中的细胞自主和肌肉中的非细胞自主的蛋白质聚集。肌肉特异性GBA表达降低了在Gba 1b果蝇EV中发现的EV内在蛋白和Ref（2）P的升高水平。通过中性鞘磷脂酶（nSMase），一种对EV释放和神经酰胺代谢很重要的酶，干扰EV生物合成，在肌肉中敲低时增强蛋白质聚集，但在神经元中敲低时不修改Gba 1b突变蛋白质聚集。nSMase敲低神经酰胺和葡萄糖神经酰胺水平的脂质组学分析表明，Gba 1b突变蛋白聚集可能取决于EV中经常富集的特定神经酰胺种类的相对消耗。最后，我们在分离的EV中鉴定了异位表达的GCase。总之，我们的研究结果表明，GCase缺乏通过失调的EV促进细胞和组织之间蛋白质聚集体的加速传播，EV介导的GCase运输可能部分解释了聚集体传播的减少。帕金森病（PD）是一种常见的神经退行性疾病，其特征在于脑和其他组织内的异常蛋白质团块（聚集体），其可导致细胞功能障碍和死亡。编码葡萄糖脑苷脂酶（GCase）的基因GBA突变是PD最强的遗传风险因素，并与更快的疾病进展相关。GCase缺陷突变果蝇显示提示PD的特征，包括脑和肌肉中蛋白质聚集增加。我们发现，在突变果蝇的肌肉中恢复GCase蛋白减少了肌肉和大脑中的蛋白质聚集，这表明了一种涉及组织之间相互作用的机制。以前的工作表明，GBA影响细胞外囊泡（EV）-细胞释放的小膜结合结构，以在细胞间进行通信和/或运输货物。在这里，我们发现突变果蝇EV内的聚集蛋白增加，这是通过恢复肌肉中的GCase而减少的。此外，我们在EV中发现了GCase，这可能解释了肌肉等组织中的GCase如何减少大脑等远处组织中的蛋白质聚集。我们的研究结果表明，GCase影响EV内的蛋白质，影响蛋白质聚集的扩散。这可能对理解PD进展很重要，并可能发现减缓神经退行性变的新靶点。
Abnormal protein aggregation within neurons is a key pathologic feature of Parkinson’s disease (PD). The spread of brain protein aggregates is associated with clinical disease progression, but how this occurs remains unclear. Mutations in glucosidase, beta acid 1 (GBA), which encodes glucocerebrosidase (GCase), are the most penetrant common genetic risk factor for PD and dementia with Lewy bodies and associate with faster disease progression. To explore how GBA mutations influence pathogenesis, we previously created a Drosophila model of GBA deficiency (Gba1b) that manifests neurodegeneration and accelerated protein aggregation. Proteomic analysis of Gba1b mutants revealed dysregulation of proteins involved in extracellular vesicle (EV) biology, and we found altered protein composition of EVs from Gba1b mutants. Accordingly, we hypothesized that GBA may influence pathogenic protein aggregate spread via EVs. We found that accumulation of ubiquitinated proteins and Ref(2)P, Drosophila homologue of mammalian p62, were reduced in muscle and brain tissue of Gba1b flies by ectopic expression of wildtype GCase in muscle. Neuronal GCase expression also rescued protein aggregation both cell-autonomously in brain and non-cell-autonomously in muscle. Muscle-specific GBA expression reduced the elevated levels of EV-intrinsic proteins and Ref(2)P found in EVs from Gba1b flies. Perturbing EV biogenesis through neutral sphingomyelinase (nSMase), an enzyme important for EV release and ceramide metabolism, enhanced protein aggregation when knocked down in muscle, but did not modify Gba1b mutant protein aggregation when knocked down in neurons. Lipidomic analysis of nSMase knockdown on ceramide and glucosylceramide levels suggested that Gba1b mutant protein aggregation may depend on relative depletion of specific ceramide species often enriched in EVs. Finally, we identified ectopically expressed GCase within isolated EVs. Together, our findings suggest that GCase deficiency promotes accelerated protein aggregate spread between cells and tissues via dysregulated EVs, and EV-mediated trafficking of GCase may partially account for the reduction in aggregate spread. Parkinson’s disease (PD) is a common neurodegenerative disease characterized by abnormal clumps of proteins (aggregates) within the brain and other tissues which can lead to cellular dysfunction and death. Mutations in the gene GBA, which encodes glucocerebrosidase (GCase), are the strongest genetic risk factor for PD, and are associated with faster disease progression. GCase-deficient mutant flies display features suggestive of PD including increased protein aggregation in brain and muscle. We found that restoring GCase protein in the muscle of mutant flies reduced protein aggregation in muscle and the brain, suggesting a mechanism involving interaction between tissues. Previous work indicated that GBA influences extracellular vesicles (EVs)–small membrane-bound structures released by cells to communicate and/or transport cargo from cell to cell. Here, we found increased aggregated proteins within EVs of mutant flies, which was reduced by restoring GCase in muscle. In addition, we found GCase within the EVs, possibly explaining how GCase in one tissue such as muscle could reduce protein aggregation in a distant tissue like the brain. Our findings suggest that GCase influences proteins within EVs, affecting the spread of protein aggregation. This may be important to understanding PD progression and could uncover new targets to slow neurodegeneration.
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影响因子：
9
作者：
Fussi N;Höllerhage M;Chakroun T;Nykänen NP;Rösler TW;Koeglsperger T;Wurst W;Behrends C;Höglinger GU
通讯作者：
Höglinger GU
影响因子：
14.5
作者：
Chu, Yaping;Muller, Scott;Kordower, Jeffrey H.
通讯作者：
Kordower, Jeffrey H.
影响因子：
15.1
作者：
Danzer KM;Kranich LR;Ruf WP;Cagsal-Getkin O;Winslow AR;Zhu L;Vanderburg CR;McLean PJ
通讯作者：
McLean PJ
影响因子：
13.3
作者：
Minakaki, Georgia;Menges, Stefanie;Klucken, Jochen
通讯作者：
Klucken, Jochen
影响因子：
5.3
作者：
Kinghorn, Kerri J.;Groenke, Sebastian;Partridge, Linda
通讯作者：
Partridge, Linda