Robustness of ex vivo, human skin as a model of general inflammation

Summary: For skin-associated, inflammatory diseases such as psoriasis and atopic dermatitis, explant skin has been used to better understand disease pathogenesis and to investigate the capabilities of experimental treatments to alter disease-specific inflammatory pathways. However, the inflammatory pathways which govern these diseases are not limited to only those of the skin. These pathways have been shown to play significant roles in several cancers and connective tissue diseases such as rheumatoid arthritis and systemic sclerosis. Given this, we investigated the potential of our <i>ex vivo</i> skin models of Th1, Th2, Th17, and LPS-mediated inflammation to be used for studies involving general inflammation in non-skin associated diseases. Here we describe the effects of various small molecule inhibitors on molecular targets which have been shown to be associated with general inflammatory response pathways. Healthy, human explants (n = 1 donor per stimulation) were treated overnight with a range of concentrations for each inhibitor (three concentrations at n = 4 replicates per concentration), followed by stimulation with our inflammatory cocktails and fresh inhibitor for 24 hours. At the conclusion, skin biopsies were collected for total RNA isolation and subsequent RT-qPCR analysis. The results for many of the inhibitors showed a robust dose response for several genes in each of the stimulation pathways, with some showing more than 50% inhibition when compared to stimulated explants only. From the data, we were able to determine the best match between each pathway target and at least one of the stimulation models. This lends evidence to the idea that our <i>ex vivo</i> skin models of Th1, Th2, Th17, and LPS-mediated inflammation can be a vital tool for investigating general inflammation outside of skin alone. Wesley LaBarge¹, Amanda V. Collins¹, Anthony Resek¹, Jon Volmer¹ 1. Research Biology, MP Pharma Services Inc, Durham, NC, United States. Adaptive and Auto-Immunity