Investigating a neuroprotective role of GBA in astrocytes

帕金森氏病(PD)的一个关键特征是大脑中神经元内蛋白质的异常聚集。 随着帕金森病的进展，这些神经元蛋白聚集体扩散到整个神经系统，但这是如何实现的 发生的原因尚不清楚。最近的研究表明，星形胶质细胞通过提供 能量和对细胞应激源的保护，也可能在帕金森病和其他疾病中起到神经保护作用 神经退行性疾病。这项建议调查了gba基因的潜在新作用，gba基因是一种常见的 帕金森病的遗传危险因素也与疾病进展较快有关。虽然大多数关于GBA的研究 只关注它在神经元中的作用，我们将测试星形胶质细胞是否需要GBA来摄取和 降解细胞外基质中的神经源性蛋白以减少致病神经元的传播 蛋白质聚集体。 我们最近使用我们的果蝇GBA缺陷模型(GBAdel)进行的研究表明，外切体是一种 调节蛋白质聚集扩散的重要载体。GBA缺乏会扰乱外切体的形成， 融合和/或内容。令人惊讶的是，我们发现野生型GBA的胶质表达可以减少蛋白质 聚集存在于GBAdel苍蝇脑中。为进一步探讨GBA在脑缺血再灌注损伤中可能的神经保护作用 星形胶质细胞，我们将使用培养的神经元和从人诱导的多能干细胞分化而来的星形胶质细胞 由携带GBA突变的帕金森病患者产生。年龄和性别匹配的无关健康对照和 通过CRISPR/Cas9将GBA突变恢复为野生型而产生的等基因对照将被用作对照。 我们将首先确定GBA是否对星形胶质细胞摄取和处理神经源性EV很重要 通过检测GBA PD与对照组星形胶质细胞摄取和细胞内转运 突触核蛋白-绿色荧光蛋白融合蛋白。然后我们将测试GBA是否通过联合-GBA对星形胶质细胞起到神经保护作用。 用GBA PD或对照神经元培养GBA PD或对照星形胶质细胞，并检测蛋白质聚集， 两种细胞中的内溶酶体运输和细胞存活。这项研究的结果可能会发现新的 增强星形胶质细胞神经保护功能的治疗目标，导致可能减缓的治疗 或者阻止帕金森病和其他以蛋白质聚集为特征的神经退行性疾病的进展。

A key feature of Parkinson’s disease (PD) is abnormal protein aggregation within neurons in the brain. These neuronal protein aggregates spread throughout the nervous system as PD progresses, but how this occurs remains unclear. Recent work suggests that astrocytes, which support neuronal function by providing energy and protection from cellular stressors, may also have a neuroprotective role in PD and other neurodegenerative diseases. This proposal investigates a potential new role for the gene GBA, a common genetic risk factor for PD that is also associated with faster disease progression. While most studies of GBA focus exclusively on its role in neurons, we will test whether GBA is required in astrocytes to uptake and degrade neuronal-derived proteins in the extracellular matrix to reduce propagation of pathogenic neuronal protein aggregates. Our recent work using our Drosophila GBA deficient model (GBAdel) of PD indicates that exosomes are an important vehicle mediating the spread of protein aggregation. GBA deficiency dysregulates exosome formation, fusion, and/or content. Surprisingly, we found that glial expression of wildtype GBA can reduce protein aggregation present in GBAdel fly brains. To further investigate a possible neuroprotective role for GBA in astrocytes, we will use cultured neurons and astrocytes differentiated from human induced pluripotent stem cells generated from PD patients carrying GBA mutations. Unrelated healthy age- and sex-matched control and isogenic controls generated by CRISPR/Cas9 reversion of the GBA mutation to wildtype will be used as controls. We will first determine whether GBA is important for astrocyte uptake and processing of neuronal-derived EVs by examining GBA PD versus control astrocyte uptake and intracellular trafficking of neuronal EVs containing synuclein-GFP fusion protein. We will then test whether GBA has a neuroprotective role in astrocytes by co- culturing GBA PD or control astrocytes with GBA PD or control neurons and examine protein aggregation, endolysosomal trafficking and cell survival in both cell types. The results from this study could uncover new therapeutic targets to enhance the neuroprotective function of astrocytes, leading to treatments that could slow or halt the progression of PD and other neurodegenerative diseases characterized by protein aggregates.