Cairns James L, Huber Johanna, Lewen Andrea, Jung Jessica, Maurer Stefan J, Bausbacher Tobias, Schmidt Stefan, Levkin Pavel A, Sevin Daniel, Göpfrich Kerstin, Koch Philipp, Kann Oliver, Hopf Carsten
Center for Mass Spectrometry and Optical Spectroscopy, CeMOS, Mannheim University of Applied Sciences, 68163, Mannheim, Germany.
Medical Faculty, Heidelberg University, 69120, Heidelberg, Germany.
Adv Sci (Weinh). 2025 Feb;12(5):e2410506. doi: 10.1002/advs.202410506. Epub 2024 Dec 12.
Single-cell MALDI mass spectrometry imaging (MSI) of lipids and metabolites >200 Da has recently come to the forefront of biomedical research and chemical biology. However, cell-targeting and metabolome-preserving methods for analysis of low mass, hydrophilic metabolites (<200 Da) in large cell populations are lacking. Here, the PRISM-MS (PRescan Imaging for Small Molecule - Mass Spectrometry) mass-guided MSI workflow is presented, which enables space-efficient single cell lipid and metabolite analysis. In conjunction with giant unilamellar vesicles (GUVs) as MSI ground truth for cell-sized objects and Monte Carlo reference-based consensus clustering for data-dependent identification of cell subpopulations, PRISM-MS enables MSI and on-cell MS2-based identification of low-mass metabolites like amino acids or Krebs cycle intermediates involved in stimulus-dependent cell activation. The utility of PRISM-MS is demonstrated through the characterization of complex metabolome changes in lipopolysaccharide (LPS)-stimulated microglial cells and human-induced pluripotent stem cell-derived microglia. Translation of single cell results to endogenous microglia in organotypic hippocampal slice cultures indicates that LPS-activation involves changes of the itaconate-to-taurine ratio and alterations in neuron-to-glia glutamine-glutamate shuttling. The data suggests that PRISM-MS can serve as a standard method in single cell metabolomics, given its capability to characterize larger cell populations and low-mass metabolites.
对脂质和分子量大于200 Da的代谢物进行单细胞基质辅助激光解吸/电离质谱成像（MSI）最近已成为生物医学研究和化学生物学的前沿领域。然而，目前缺乏针对大细胞群体中低分子量亲水性代谢物（<200 Da）的细胞靶向和代谢组保留分析方法。在此，我们提出了PRISM-MS（小分子质谱预扫描成像）质量引导的MSI工作流程，该流程能够实现高效的单细胞脂质和代谢物分析。结合作为细胞大小物体的MSI基础真值的巨型单层囊泡（GUV）以及基于蒙特卡罗参考的共识聚类用于数据依赖的细胞亚群识别，PRISM-MS能够进行MSI以及基于细胞上MS2的低分子量代谢物识别，如参与刺激依赖性细胞激活的氨基酸或三羧酸循环中间体。通过对脂多糖（LPS）刺激的小胶质细胞和人诱导多能干细胞衍生的小胶质细胞中复杂代谢组变化的表征，证明了PRISM-MS的实用性。将单细胞结果转化为器官型海马切片培养物中的内源性小胶质细胞表明，LPS激活涉及衣康酸与牛磺酸比率的变化以及神经元与神经胶质谷氨酰胺 - 谷氨酸穿梭的改变。数据表明，鉴于PRISM-MS能够表征更大的细胞群体和低分子量代谢物，它可以作为单细胞代谢组学的标准方法。
