Proteomics and Substrate Based MS Imaging of Xenobiotic Metabolising Enzymes in Ex Vivo Human Skin and a Human Living Skin Equivalent Model

Current animal-free approaches for assessing the metabolism of xenobiotics in skin are limited. The primary reason for this is that the levels and distribution of xenobiotic metabolising enzymes in skin are not well characterised. The overall aim of this project was to develop a combined in silico-in vitro system for predicting xenobiotic metabolism in human skin from experiments carried out on a living skin equivalent (LSE). In order to do this it was required to systematically quantify the level of xenobiotic metabolising enzymes in skin and in Labskin using proteomics.

In order to examine the distribution of enzymes detected, a novel substrate-based mass spectrometry imaging technique was proposed that would allow the activity of xenobiotic metabolising enzymes to be localised within the in vitro model. Ultimately the project will use these proteomic and imaging data to build a pharmacokinetic (PBPK) model of human skin xenobiotic metabolism and disposition to enable in vitro to in vivo extrapolation (IVIVE) of LSE based xenobiotic metabolism data. This integrated solution would then offer an animal-free alternative that will increase screening capacity and knowledge of xenobiotic skin metabolism.