MOE Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Department of Chemistry, Tsinghua University, 100084, Beijing, China.
Bytedance Technology Co., 201103, Shanghai, China.
Nat Commun. 2023 Jul 17;14(1):4263. doi: 10.1038/s41467-023-40046-x.
A lipidome comprises thousands of lipid species, many of which are isomers and isobars. Liquid chromatography-tandem mass spectrometry (LC-MS/MS), although widely used for lipidomic profiling, faces challenges in differentiating lipid isomers. Herein, we address this issue by leveraging the orthogonal separation capabilities of hydrophilic interaction liquid chromatography (HILIC) and trapped ion mobility spectrometry (TIMS). We further integrate isomer-resolved MS/MS methods onto HILIC-TIMS, which enable pinpointing double bond locations in phospholipids and sn-positions in phosphatidylcholine. This system profiles phospholipids at multiple structural levels with short analysis time (<10 min per LC run), high sensitivity (nM detection limit), and wide coverage, while data analysis is streamlined using a home-developed software, LipidNovelist. Notably, compared to our previous report, the system doubles the coverage of phospholipids in bovine liver and reveals uncanonical desaturation pathways in RAW 264.7 macrophages. Relative quantitation of the double bond location isomers of phospholipids and the sn-position isomers of phosphatidylcholine enables the phenotyping of human bladder cancer tissue relative to normal control, which would be otherwise indistinguishable by traditional profiling methods. Our research offers a comprehensive solution for lipidomic profiling and highlights the critical role of isomer analysis in studying lipid metabolism in both healthy and diseased states.
脂质组学包含数千种脂质种类，其中许多是同分异构体和同系物。尽管液相色谱-串联质谱（LC-MS/MS）广泛用于脂质组学分析，但在区分脂质同分异构体方面仍面临挑战。在此，我们通过利用亲水相互作用色谱（HILIC）和离子淌度质谱（TIMS）的正交分离能力来解决这个问题。我们进一步将分辨异构体的 MS/MS 方法整合到 HILIC-TIMS 中，这使得我们能够精确定位磷脂中的双键位置和磷脂酰胆碱中的 sn-位。该系统能够在短分析时间（<10 分钟/LC 运行）、高灵敏度（nM 检测限）和广泛覆盖范围内，在多个结构水平上对磷脂进行分析，同时使用自主开发的软件 LipidNovelist 简化数据分析。值得注意的是，与我们之前的报告相比，该系统将牛肝磷脂的覆盖范围提高了一倍，并在 RAW 264.7 巨噬细胞中揭示了非常规的去饱和途径。对磷脂双键位置异构体和磷脂酰胆碱 sn-位置异构体的相对定量，使我们能够对膀胱癌组织进行表型分析，而传统的分析方法则无法区分膀胱癌组织和正常组织。我们的研究为脂质组学分析提供了全面的解决方案，并强调了异构体分析在研究健康和疾病状态下脂质代谢中的关键作用。
