Little is known about the metabolic regulation of rare cell populations because most metabolites are hard to detect in small numbers of cells. We previously described a method for metabolomic profiling of flow cytometrically-isolated hematopoietic stem cells (HSCs) that detects 60 metabolites in 10,000 cells (Agathocleous et al., 2017). Here we describe a new method involving hydrophilic liquid interaction chromatography and high-sensitivity orbitrap mass spectrometry that detected 160 metabolites in 10,000 HSCs, including many more glycolytic and lipid intermediates. We improved chromatographic separation, increased mass resolution, minimized ion suppression, and eliminated sample drying. Most metabolite levels did not significantly change during cell isolation. Mouse HSCs exhibited increased glycerophospholipids relative to bone marrow cells and methotrexate treatment altered purine biosynthesis. Circulating human melanoma cells were depleted for purine intermediates relative to subcutaneous tumors, suggesting decreased purine synthesis during metastasis. These methods facilitate the routine metabolomic analysis of rare cells from tissues.

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通过流式细胞术从组织中分离的稀有细胞群的代谢组学分析

关于稀有细胞群的代谢调节知之甚少，因为大多数代谢物很难在少量细胞中检测到。我们之前描述了一种对流式细胞术分离的造血干细胞 (HSC) 进行代谢组学分析的方法，该方法可检测 10,000 个细胞中的 60 种代谢物（Agathocleous 等人，2017 年）。在这里，我们描述了一种涉及亲水性液体相互作用色谱法和高灵敏度轨道阱质谱法的新方法，该方法检测了 10,000 个 HSC 中的 160 种代谢物，包括更多的糖酵解和脂质中间体。我们改进了色谱分离，提高了质量分辨率，最大限度地减少了离子抑制，并消除了样品干燥。大多数代谢物水平在细胞分离过程中没有显着变化。相对于骨髓细胞，小鼠 HSC 表现出增加的甘油磷脂，甲氨蝶呤治疗改变了嘌呤的生物合成。相对于皮下肿瘤，循环人​​类黑色素瘤细胞的嘌呤中间体被耗尽，这表明在转移过程中嘌呤合成减少。这些方法有助于对组织中的稀有细胞进行常规代谢组学分析。