Mitochondrial dysfunction is implicated in Parkinson disease (PD). Mutations in Parkin, an E3 ubiquitin ligase, can cause juvenile-onset Parkinsonism, probably through impairment of mitophagy. Inhibition of the de-ubiquitinating enzyme USP30 may counter this effect to enhance mitophagy. Using different tools and cellular approaches, we wanted to independently confirm this claimed role for USP30. Pharmacological characterisation of additional tool compounds that selectively inhibit USP30 are reported. The consequence of USP30 inhibition by these compounds, siRNA knockdown and overexpression of dominant-negative USP30 on the mitophagy pathway in different disease-relevant cellular models was explored. Knockdown and inhibition of USP30 showed increased p-Ser65-ubiquitin levels and mitophagy in neuronal cell models. Furthermore, patient-derived fibroblasts carrying pathogenic mutations in Parkin showed reduced p-Ser65-ubiquitin levels compared with wild-type cells, levels that could be restored using either USP30 inhibitor or dominant-negative USP30 expression. Our data provide additional support for USP30 inhibition as a regulator of the mitophagy pathway.

中文翻译：

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研究 USP30 抑制以增强 Parkin 介导的线粒体自噬：工具和方法

线粒体功能障碍与帕金森病（PD）有关。Parkin 是一种 E3 泛素连接酶，其突变可导致幼年型帕金森症，可能是通过线粒体自噬受损。去泛素化酶 USP30 的抑制可能会抵消这种增强线粒体自噬的作用。使用不同的工具和细胞方法，我们希望独立确认 USP30 所声称的作用。报道了选择性抑制 USP30 的其他工具化合物的药理学特征。探讨了这些化合物抑制 USP30、siRNA 敲低和显性失活 USP30 在不同疾病相关细胞模型中对线粒体自噬途径的过表达的结果。USP30 的敲低和抑制显示神经元细胞模型中 p-Ser65-泛素水平和线粒体自噬增加。此外，与野生型细胞相比，携带 Parkin 致病突变的患者来源的成纤维细胞显示出降低的 p-Ser65-泛素水平，使用 USP30 抑制剂或显性阴性 USP30 表达可以恢复水平。我们的数据为 USP30 抑制作为线粒体自噬途径的调节剂提供了额外的支持。