Winter Martin, Tholey Andreas, Kristen Arnt, Röcken Christoph
Department of Pathology, Christian-Albrechts-University, Kiel, Germany.
Systematic Proteome Research & Bioanalytics, Institute of Experimental Medicine, Christian-Albrechts-University, Kiel, Germany.
Proteomics. 2017 Nov;17(22). doi: 10.1002/pmic.201700236.
Amyloidosis is a group of diseases caused by extracellular accumulation of fibrillar polypeptide aggregates. So far, diagnosis is performed by Congo red staining of tissue sections in combination with polarization microscopy. Subsequent identification of the causative protein by immunohistochemistry harbors some difficulties regarding sensitivity and specificity. Mass spectrometry based approaches have been demonstrated to constitute a reliable method to supplement typing of amyloidosis, but still depend on Congo red staining. In the present study, we used matrix-assisted laser desorption/ionization mass spectrometry imaging coupled with ion mobility separation (MALDI-IMS MSI) to investigate amyloid deposits in formalin-fixed and paraffin-embedded tissue samples. Utilizing a novel peptide filter method, we found a universal peptide signature for amyloidoses. Furthermore, differences in the peptide composition of ALλ and ATTR amyloid were revealed and used to build a reliable classification model. Integrating the peptide filter in MALDI-IMS MSI analysis, we developed a bioinformatics workflow facilitating the identification and classification of amyloidosis in a less time and sample-consuming experimental setup. Our findings demonstrate also the feasibility to investigate the amyloid's protein composition, thus paving the way to establish classification models for the diverse types of amyloidoses and to shed further light on the complex process of amyloidogenesis.
淀粉样变性是一组由纤维状多肽聚集体在细胞外积聚引起的疾病。到目前为止，诊断是通过组织切片的刚果红染色结合偏振显微镜进行的。随后通过免疫组织化学鉴定致病蛋白在敏感性和特异性方面存在一些困难。基于质谱的方法已被证明是补充淀粉样变性分型的可靠方法，但仍依赖于刚果红染色。在本研究中，我们使用基质辅助激光解吸/电离质谱成像结合离子淌度分离（MALDI-IMS MSI）来研究福尔马林固定石蜡包埋组织样本中的淀粉样沉积物。利用一种新型肽筛选方法，我们发现了淀粉样变性的通用肽特征。此外，还揭示了ALλ和ATTR淀粉样蛋白的肽组成差异，并用于建立可靠的分类模型。将肽筛选整合到MALDI-IMS MSI分析中，我们开发了一种生物信息学工作流程，在耗时更少和样本消耗更少的实验设置中促进淀粉样变性的鉴定和分类。我们的研究结果还证明了研究淀粉样蛋白的蛋白质组成的可行性，从而为建立不同类型淀粉样变性的分类模型以及进一步阐明淀粉样蛋白生成的复杂过程铺平了道路。
