Mutations in the β-glucocerebrosidase (GBA1) gene do cause the lysosomal storage Gaucher disease (GD) and are among the most frequent genetic risk factors for Parkinson’s disease (PD). So far, studies on both neuronopathic GD and PD primarily focused on neuronal manifestations, besides the evaluation of microglial and astrocyte implication. White matter alterations were described in the central nervous system of paediatric type 1 GD patients and were suggested to sustain or even play a role in the PD process, although the contribution of oligodendrocytes has been so far scarcely investigated. We exploited a system to study the induction of central myelination in vitro, consisting of Oli-neu cells treated with dibutyryl-cAMP, in order to evaluate the expression levels and function of β-glucocerebrosidase during oligodendrocyte differentiation. Conduritol-B-epoxide, a β-glucocerebrosidase irreversible inhibitor was used to dissect the impact of β-glucocerebrosidase inactivation in the process of myelination, lysosomal degradation and α-synuclein accumulation in vitro. Moreover, to study the role of β-glucocerebrosidase in the white matter in vivo, we developed a novel mouse transgenic line in which β-glucocerebrosidase function is abolished in myelinating glia, by crossing the Cnp1-cre mouse line with a line bearing loxP sequences flanking Gba1 exons 9–11, encoding for β-glucocerebrosidase catalytic domain. Immunofluorescence, western blot and lipidomic analyses were performed in brain samples from wild-type and knockout animals in order to assess the impact of genetic inactivation of β-glucocerebrosidase on myelination and on the onset of early neurodegenerative hallmarks, together with differentiation analysis in primary oligodendrocyte cultures. Here we show that β-glucocerebrosidase inactivation in oligodendrocytes induces lysosomal dysfunction and inhibits myelination in vitro. Moreover, oligodendrocyte-specific β-glucocerebrosidase loss-of-function was sufficient to induce in vivo demyelination and early neurodegenerative hallmarks, including axonal degeneration, α-synuclein accumulation and astrogliosis, together with brain lipid dyshomeostasis and functional impairment. Our study sheds light on the contribution of oligodendrocytes in GBA1-related diseases and supports the need for better characterizing oligodendrocytes as actors playing a role in neurodegenerative diseases, also pointing at them as potential novel targets to set a brake to disease progression.

中文翻译：

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少突胶质细胞中 GBA1 失活影响髓鞘形成并诱导小鼠神经退行性特征和脂质动态平衡

β-葡萄糖脑苷脂酶 (GBA1) 基因突变确实会导致溶酶体贮积戈谢病 (GD)，并且是帕金森病 (PD) 最常见的遗传风险因素之一。迄今为止，除了评估小胶质细胞和星形胶质细胞的影响外，对神经病性 GD 和 PD 的研究主要集中在神经元表现上。1 型 GD 儿科患者中枢神经系统中的白质改变被描述为维持甚至在 PD 过程中发挥作用，尽管迄今为止很少研究少突胶质细胞的贡献。我们利用一个系统来研究体外中枢髓鞘形成的诱导，该系统由用二丁酰-cAMP处理的Oli-neu细胞组成，以评估少突胶质细胞分化过程中β-葡萄糖脑苷脂酶的表达水平和功能。β-葡萄糖脑苷脂酶不可逆抑制剂Conduritol-B-环氧化物用于在体外剖析β-葡萄糖脑苷脂酶失活对髓鞘形成、溶酶体降解和α-突触核蛋白积累过程的影响。此外，为了研究 β-葡萄糖脑苷脂酶在体内白质中的作用，我们通过将 Cnp1-cre 小鼠系与带有 loxP 序列的小鼠系杂交，开发了一种新型小鼠转基因系，其中髓鞘神经胶质细胞中的 β-葡萄糖脑苷脂酶功能被消除。侧翼 Gba1 外显子 9-11，编码 β-葡萄糖脑苷脂酶催化结构域。对野生型和基因敲除动物的脑样本进行免疫荧光、蛋白质印迹和脂质组学分析，以评估 β-葡萄糖脑苷脂酶基因失活对髓鞘形成和早期神经退行性标志发作的影响，同时对原代少突胶质细胞进行分化分析文化。在这里，我们发现少突胶质细胞中的β-葡萄糖脑苷脂酶失活会诱导溶酶体功能障碍并抑制体外髓鞘形成。此外，少突胶质细胞特异性β-葡萄糖脑苷脂酶功能丧失足以诱导体内脱髓鞘和早期神经退行性标志，包括轴突变性、α-突触核蛋白积累和星形胶质细胞增生，以及脑脂质失衡和功能损伤。我们的研究揭示了少突胶质细胞在 GBA1 相关疾病中的贡献，并支持需要更好地将少突胶质细胞描述为在神经退行性疾病中发挥作用的参与者，同时指出它们是阻止疾病进展的潜在新靶标。