Imaging of protein distribution in tissues using mass spectrometry: An interdisciplinary challenge

• Published in: TrAC, Trends in analytical chemistry (Regular ed.) Trends in analytical chemistry (Regular ed.), 2019-03, Vol.112, p.13-28
• Main Authors: Han, Jiaying, Permentier, Hjalmar, Bischoff, Rainer, Groothuis, Geny, Casini, Angela, Horvatovich, Péter
• Format: Article
• Language: English
• ISSN: 0165-9936; 1879-3142
• DOI: 10.1016/j.trac.2018.12.016

The recent development of mass spectrometry imaging (MSI) technology allowed to obtain extremely detailed images of the spatial distribution of proteins in tissue at high spatial resolution reaching cell dimensions, high target specificity and a large dynamic concentration range. This review focusses on the development of two main MSI principles, namely targeted and untargeted detection of protein distribution in tissue samples, with special emphasis on the improvements in analyzed mass range and spatial resolution over the last 10 years. Untargeted MSI of in situ digested proteins with matrix-assisted laser desorption ionization is the most widely used approach, but targeted protein MSI technologies using laser ablation inductively coupled plasma (LA-ICP) and photocleavable mass tag chemical labeling strategies are gaining momentum. Moreover, this review also provides an overview of the effect of sample preparation on image quality and the bioinformatic challenge to identify proteins and quantify their distribution in complex MSI data. •Mass spectrometry imaging is an untargeted analytical technology to determine protein distribution in tissue section.•Spatial resolution is key parameter of mass spectrometry imaging.•Protein identification from tissue is still challenging.•Pre-processing of large mass spectrometry imaging data requires efficient data structures and complex processing workflow.•Photocleavable mass tags allow multiplexed imaging of low abundant proteins with high spatial resolution.