Mechanism of alpha-synuclein aggregate clearance by Rab7

Rab7 清除 α-突触核蛋白聚集体的机制

• 批准号: 416974498
• 负责人: Professor Dr. Björn Falkenburger
• 金额: --
• 依托单位: Klinik und Poliklinik für Neurologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/416974498?language=en
• 关键词: Mechanism; alpha; synuclein; aggregate; clearance

Parkinson's disease is characterized by aggregates of misfolded proteins, in particular alpha-synuclein. Our aim is to stop progression of Parkinson's disease by inducing clearance of alpha-synuclein aggregates.Aggregates are degraded by autophagy where pieces of cytosol are engulfed by a membrane. These autophagosomes subsequently fuse with lysosomes to degrade their content. In previous work we could show that autolysosomal degradation of alpha-synuclein aggregates is induced by overexpression of Rab7. Several Rab proteins promote aggregate clearance, but Rab7 is of particular interest since it mediates effects of PINK, parkin and LRRK2. Mutations in the genes that encode these proteins are associated with familial Parkinson's disease. The most important effector of Rab7 is FYCO1 (FYVE and coiled-coiled domain containing 1).In order to further develop our previous work into a therapeutic strategy for Parkinson's disease we will use two strategies. First, we will validate our findings from cell lines and drosophila melanogaster in models that resemble the clinical situation mor closely. We will therefore test Rab7, FYCO1 and further interventions in primary mouse neurons and in a mouse model using intracerebral injection of alpha-synuclein fibrils.In a second approach we aim to understand how Rab7-induced aggregate clearance works in order to design better manipulations for the future. Many steps and factors are involved in aggregate clerance. To focus our efforts we therefoer formulated two testable hypotheses based on our preliminary experiments:- Fusion of autophagosomes with lysosomes is the rate-limiting step of aggregate clearance. - Cholesterol transport at contact sites between autophagosomes and the ER is necessary for aggregate clearance.We will also investigate the relevance of intracellular transport and secretion for aggregate clearance.

帕金森病的特征是错误折叠的蛋白质聚集，特别是α -突触核蛋白。我们的目标是通过诱导α -突触核蛋白聚集体的清除来阻止帕金森病的进展。聚集体通过自噬降解，其中细胞质碎片被膜吞没。这些自噬体随后与溶酶体融合以降解其内容物。在先前的工作中，我们可以证明Rab7的过表达诱导了α -突触核蛋白聚集体的自溶酶体降解。几种Rab蛋白促进聚集清除，但Rab7是特别感兴趣的，因为它介导PINK， parkin和LRRK2的作用。编码这些蛋白质的基因突变与家族性帕金森病有关。Rab7最重要的效应因子是FYCO1 （FYVE和coiled-coiled domain containing 1）。为了进一步将我们之前的工作发展成帕金森病的治疗策略，我们将使用两种策略。首先，我们将在更接近临床情况的模型中验证来自细胞系和黑腹果蝇的发现。因此，我们将通过脑内注射α -突触核蛋白原纤维在小鼠初代神经元和小鼠模型中测试Rab7、FYCO1和进一步的干预。在第二种方法中，我们的目标是了解rab7诱导的聚集体清除如何工作，以便为未来设计更好的操作。总公差涉及许多步骤和因素。因此，为了集中我们的努力，我们基于我们的初步实验制定了两个可测试的假设：-自噬体与溶酶体的融合是聚集体清除的限速步骤。-自噬体与内质网接触部位的胆固醇运输是清除总胆固醇的必要条件。我们还将研究细胞内运输和分泌与聚集体清除的相关性。