Here we report the application of a mass spectrometry-based technology, imaging mass cytometry, to perform in-depth proteomic profiling of mitochondrial complexes in single neurons, using metal-conjugated antibodies to label post-mortem human midbrain sections. Mitochondrial dysfunction, particularly deficiency in complex I has previously been associated with the degeneration of dopaminergic neurons in Parkinson’s disease. To further our understanding of the nature of this dysfunction, and to identify Parkinson’s disease specific changes, we validated a panel of antibodies targeting subunits of all five mitochondrial oxidative phosphorylation complexes in dopaminergic neurons from Parkinson’s disease, mitochondrial disease, and control cases. Detailed analysis of the expression profile of these proteins, highlighted heterogeneity between individuals. There is a widespread decrease in expression of all complexes in Parkinson’s neurons, although more severe in mitochondrial disease neurons, however, the combination of affected complexes varies between the two groups. We also provide evidence of a potential neuronal response to mitochondrial dysfunction through a compensatory increase in mitochondrial mass. This study highlights the use of imaging mass cytometry in the assessment and analysis of expression of oxidative phosphorylation proteins, revealing the complexity of deficiencies of these proteins within individual neurons which may contribute to and drive neurodegeneration in Parkinson’s disease.

在这里，我们报告了基于质谱技术的应用，即成像质量细胞术，使用金属偶联抗体来标记死后人类中脑切片，对单个神经元中的线粒体复合物进行深入的蛋白质组学分析。线粒体功能障碍，特别是复合物 I 的缺乏，此前已被认为与帕金森病中多巴胺能神经元的退化有关。为了进一步了解这种功能障碍的性质，并确定帕金森病的具体变化，我们验证了一组针对帕金森病、线粒体病和对照病例的多巴胺能神经元中所有五个线粒体氧化磷酸化复合物亚基的抗体。对这些蛋白质表达谱的详细分析突出了个体之间的异质性。帕金森氏症神经元中所有复合物的表达均普遍下降，尽管线粒体疾病神经元中的情况更为严重，但两组中受影响的复合物的组合有所不同。我们还提供了通过线粒体质量代偿性增加对线粒体功能障碍产生潜在神经元反应的证据。这项研究强调了成像质量流式细胞术在评估和分析氧化磷酸化蛋白表达中的应用，揭示了单个神经元内这些蛋白质缺陷的复杂性，这可能导致和驱动帕金森病的神经变性。