Department of Chemistry , Tsinghua University , Beijing 100084 , P.R. China.
Anal Chem. 2019 Aug 6;91(15):9777-9783. doi: 10.1021/acs.analchem.9b01419. Epub 2019 Jul 10.
Comprehensive analysis of single-cell metabolites is critical since differences in cellular chemical compositions give rise to specialized biological functions. Herein, we propose a label-free mass cytometry by coupling flow cytometry to ESI-MS (named CyESI-MS) for high-coverage and high-throughput detection of cellular metabolites. Cells in suspension were isolated, online extracted by sheath fluid, and lysed during gas-assisted electrospray, followed by real-time MS analysis. Hundreds of metabolites, including nucleotides, amino acids, peptides, carbohydrates, fatty acyls, glycerolipids, glycerophospholipids, and sphingolipids, were detected and identified from one single cell. Discrimination of four types of cancer cell lines and even three subtypes of breast cancer cells was readily achieved using their distinct metabolic profiles. Furthermore, we screened out 102 characteristic ions from 615 detected peak signals for distinguishing breast cancer cell subtypes and identified 40 characteristic molecules which exhibited significant differences among these subtypes and would be potential metabolic markers for clinical diagnosis. CyESI-MS is expected to be a new-generation mass cytometry for studying cell heterogeneity on the metabolic level.
单细胞代谢物的全面分析至关重要，因为细胞化学成分的差异赋予了其特有的生物学功能。在此，我们提出了一种无标记的质谱流式细胞术，通过将流式细胞术与 ESI-MS 相结合（命名为 CyESI-MS），用于高通量和高覆盖度的细胞代谢物检测。悬浮细胞被分离出来，在线通过鞘液提取，并在气助电喷雾过程中裂解，随后进行实时 MS 分析。从单个细胞中检测和鉴定了数百种代谢物，包括核苷酸、氨基酸、肽、碳水化合物、脂肪酸、甘油酯、甘油磷脂和鞘脂。利用不同的代谢谱，很容易区分四种类型的癌细胞系，甚至三种亚型的乳腺癌细胞。此外，我们从 615 个检测到的峰信号中筛选出 102 个特征离子，用于区分乳腺癌细胞亚型，并鉴定出 40 个特征分子，这些分子在这些亚型之间存在显著差异，可能成为临床诊断的潜在代谢标志物。CyESI-MS 有望成为新一代的质谱流式细胞术，用于研究代谢水平上的细胞异质性。
