Research Article
MALDI imaging mass spectrometry of N-linked glycans on formalin-fixed paraffin-embedded murine kidney
Ove J. R. Gustafsson, Matthew T. Briggs, Mark R. Condina, Lyron J. Winderbaum, Matthias Pelzing, Shaun R. McColl, Arun V. Everest-Dass, Nicolle H. Packer, Peter Hoffmann
Published:
December 02, 2014
DOI:
10.1007/s00216-014-8293-7
License:
© The Author(s) 2014
Open AccessThis article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided the original author(s) and the source are credited.
Abstract
Recent developments in spatial proteomics have paved the way for retrospective in situ mass spectrometry (MS) analyses of formalin-fixed paraffin-embedded clinical tissue samples. This type of analysis is commonly referred to as matrix-assisted laser desorption/ionization (MALDI) imaging. Recently, formalin-fixed paraffin-embedded MALDI imaging analyses were augmented to allow in situ analyses of tissue-specific N-glycosylation profiles. In the present study, we outline an improved automated sample preparation method for N-glycan MALDI imaging, which uses in situ PNGase F-mediated release and measurement of N-linked glycans from sections of formalin-fixed murine kidney. The sum of the presented data indicated that N-glycans can be cleaved from proteins within formalin-fixed tissue and characterized using three strategies: (i) extraction and composition analysis through on-target MALDI MS and liquid chromatography coupled to electrospray ionization ion trap MS; (ii) MALDI profiling, where N-glycans are released and measured from large droplet arrays in situ; and (iii) MALDI imaging, which maps the tissue specificity of N-glycans at a higher resolution. Thus, we present a complete, straightforward method that combines MALDI imaging and characterization of tissue-specific N-glycans and complements existing strategies.Graphical AbstractMALDI imaging MS of N-linked glycans released from formalin-fixed paraffin-embedded murine kidney sections. Ion intensity maps for (Hex)2(HexNAc)3(Deoxyhexose)3+(Man)3(GlcNAc)2 (m/z 2304.932, red), (Hex)6+(Man)3(GlcNAc)2 (m/z 1905.742, green) and (Hex)2(HexNAc)2+(Man)3(GlcNAc)2 (m/z 1663.756, blue)Electronic supplementary materialThe online version of this article (doi:10.1007/s00216-014-8293-7) contains supplementary material, which is available to authorized users.