Advances in mass spectrometry imaging enabling observation of localised lipid biochemistry within tissues

There are numerous reports demonstrating the heterogeneous spatial distributions of lipids throughout biology using mass spectrometry imaging (MSI). However, despite these and the biological significance of lipid alterations there remains a surprising lack of understanding regarding the underlying origins of the spatial distributions detected with MSI. With the rapid improvements in analytical capabilities of MSI instrumentation, it is now at the point that these biological questions can begin to be addressed. In this review we focus on (i) work providing insight into the biochemical origins of lipid spatial distributions, with an emphasis on the role of localised enzymatic processes in determining lipid compositions; (ii) use of stable isotope labelling to spatially-resolve the kinetics of lipid synthesis; and (iii) current challenges faced by the lipid MSI community and new analytical methods to overcome them. Combined, these topics highlight the added biological information that can be acquired from the MSI of lipids. (c) 2018 Elsevier B.V. All rights reserved.