Department of Chemistry and Institutes of Biomedical Sciences, Fudan University, Shanghai, 200433, China.
Department of Radiation Oncology, Fudan University Shanghai Cancer Center; Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, China.
Anal Chem. 2020 Jul 7;92(13):9239-9246. doi: 10.1021/acs.analchem.0c01572. Epub 2020 Jun 18.
The heterogeneous populations of exosomes with distinct nanosize have impeded our understanding of their corresponding function as intercellular communication agents. Profiling signaling proteins packaged in each size-dependent subtype can disclose this heterogeneity of exosomes. Herein, new strategy was developed for deconstructing heterogeneity of distinct-size urine exosome subpopulations by profiling N-glycoproteomics and phosphoproteomics simultaneously. Two-dimension size exclusion liquid chromatography (SEC) was utilized to isolate large exosomes (L-Exo), medium exosomes (M-Exo), and small exosomes (S-Exo) from human urine samples. Then, hydrophilic carbonyl-functionalized magnetic zirconium-organic framework (CFMZOF) was developed as probe for capturing the two kinds of post-translational modification (PTM) peptides simultaneously. Finally, liquid chromatography-tandem mass spectrometry (LC-MS/MS) combined with database search was used to characterize PTM protein contents. We identified 144 glycoproteins and 44 phosphoproteins from L-Exo, 156 glycoproteins, and 46 phosphoproteins from M-Exo and 134 glycoproteins and 10 phosphoproteins from S-Exo. The ratio of the proteins with simultaneous glycosylation and phosphorylation is 11%, 9%, and 3% in L-Exo, M-Exo, and S-Exo, respectively. Based on label-free quantification intensity results, both principal component analysis and Pearson's correlation coefficients indicate that distinct-size exosome subpopulations exist significant differences in PTM protein contents. Analysis of high abundance PTM proteins in each exosome subset reveals that the preferentially packaged PTM proteins in L-Exo, M-Exo, and S-Exo are associated with immune response, biological metabolism, and molecule transport processes, respectively. Our PTM proteomics study based on size-dependent exosome subtypes opens a new avenue for deconstructing the heterogeneity of exosomes.
外泌体的异质群体具有不同的纳米尺寸,这阻碍了我们对其作为细胞间通讯介质的相应功能的理解。对每种大小依赖性亚型中包装的信号蛋白进行分析,可以揭示外泌体的这种异质性。在此,通过同时进行 N-糖蛋白组学和磷酸化蛋白质组学分析,开发了一种用于构建不同大小尿液外泌体亚群异质性的新策略。二维尺寸排阻液相色谱 (SEC) 用于从人尿样中分离大外泌体 (L-Exo)、中体外泌体 (M-Exo) 和小外泌体 (S-Exo)。然后,开发了亲水性羰基功能化磁性锆有机骨架 (CFMZOF) 作为同时捕获两种翻译后修饰 (PTM) 肽的探针。最后,采用液相色谱-串联质谱 (LC-MS/MS) 结合数据库搜索来鉴定 PTM 蛋白含量。我们从 L-Exo 中鉴定出 144 种糖蛋白和 44 种磷酸化蛋白,从 M-Exo 中鉴定出 156 种糖蛋白和 46 种磷酸化蛋白,从 S-Exo 中鉴定出 134 种糖蛋白和 10 种磷酸化蛋白。L-Exo、M-Exo 和 S-Exo 中同时发生糖基化和磷酸化的蛋白比例分别为 11%、9%和 3%。基于无标记定量强度结果,主成分分析和 Pearson 相关系数均表明不同大小的外泌体亚群在 PTM 蛋白含量上存在显著差异。对每个外泌体亚群中的高丰度 PTM 蛋白进行分析表明,L-Exo、M-Exo 和 S-Exo 中优先包装的 PTM 蛋白分别与免疫反应、生物代谢和分子转运过程相关。我们基于大小依赖性外泌体亚型的 PTM 蛋白质组学研究为外泌体异质性的构建开辟了新途径。