Visualization of Localized Cellular Signalling Mediators in Tissues by Imaging Mass Spectrometry

Abstract

Low-molecular-weight cellular signalling mediators orchestrate a programmed progression of a series of biological phenomena, including inflammation. In order to understand the biochemical basis of inflammatory diseases, it is important to first understand the spatiotemporal dynamics (i.e., production, diffusion , decomposition) of such inflammatory mediators in tissues; however, the lack of effective molecular imaging technology has made it difficult to determine their localisations in vivo. Because the in vivo concentrations of these mediators are maintained at low levels due to their strong ability to induce an inflammatory response, technological breakthroughs in molecular imaging methods toward a highly sensitive technology sufficient to detect inflammatory mediators in tissues are required. We and other groups have attempted to fill this technical gap by developing highly sensitive imaging mass spectrometry (IMS) technologies. Owing to recent improvements in IMS regarding its sensitivity, molecular coverage, and spatial resolution, this imaging technology is expected to be a powerful and practical tool to reveal unexpected dynamics of inflammatory mediators in the tissues involved in chronic inflammation. Here, we review recent progress in the development of this technology and demonstrate how the highly sensitive IMS technique has