Multiparametric Tissue Characterization Utilizing the Cellular Metallome and Immuno-Mass Spectrometry Imaging

Author(s)
Martin Schaier, Sarah Theiner, Dina Baier, Gabriel Braun, Walter Berger, Gunda Koellensperger
Abstract

In this study, we present a workflow that enables spatial single-cell metallomics in tissue decoding the cellular heterogeneity. Low-dispersion laser ablation in combination with inductively coupled plasma time-of-flight mass spectrometry (LA-ICP-TOFMS) provides mapping of endogenous elements with cellular resolution at unprecedented speed. Capturing the heterogeneity of the cellular population by metals only is of limited use as the cell type, functionality, and cell state remain elusive. Therefore, we expanded the toolbox of single-cell metallomics by integrating the concepts of imaging mass cytometry (IMC). This multiparametric assay successfully utilizes metal-labeled antibodies for cellular tissue profiling. One important challenge is the need to preserve the original metallome in the sample upon immunostaining. Therefore, we studied the impact of extensive labeling on the obtained endogenous cellular ionome data by quantifying elemental levels in consecutive tissue sections (with and without immunostaining) and correlating elements with structural markers and histological features. Our experiments showed that the elemental tissue distribution remained intact for selected elements such as sodium, phosphorus, and iron, while absolute quantification was precluded. We hypothesize that this integrated assay not only advances single-cell metallomics (enabling to link metal accumulation to multi-dimensional characterization of cells/cell populations), but in turn also enhances selectivity in IMC, as in selected cases, labeling strategies can be validated by elemental data. We showcase the power of this integrated single-cell toolbox using an in vivo tumor model in mice and provide mapping of the sodium and iron homeostasis as linked to different cell types and function in mouse organs (such as spleen, kidney, and liver). Phosphorus distribution maps added structural information, paralleled by the DNA intercalator visualizing the cellular nuclei. Overall, iron imaging was the most relevant addition to IMC. In tumor samples, for example, iron-rich regions correlated with high proliferation and/or located blood vessels, which are key for potential drug delivery.

Organisation(s)
Department of Analytical Chemistry, Department of Inorganic Chemistry
External organisation(s)
Medizinische Universität Wien
Journal
JACS Au
Volume
3
Pages
419-428
No. of pages
10
ISSN
2691-3704
DOI
https://doi.org/10.1021/jacsau.2c00571
Publication date
02-2023
Peer reviewed
Yes
Austrian Fields of Science 2012
104002 Analytical chemistry, 106057 Metabolomics
Keywords
ASJC Scopus subject areas
Chemistry (miscellaneous), Analytical Chemistry, Organic Chemistry, Physical and Theoretical Chemistry
Portal url
https://ucris.univie.ac.at/portal/en/publications/multiparametric-tissue-characterization-utilizing-the-cellular-metallome-and-immunomass-spectrometry-imaging(2290ce3e-c0fd-4eae-ab91-70a1aedd67f4).html