Determination of chemical irritation potential using a defined gene signature set on tissue-engineered human skin equivalents

There are no physical or visual manifestations that define skin sensitivity or irritation; a subjective diagnosis is made based on the evaluation of clinical presentations including burning, prickling, erythema and itching. Adverse skin reaction in response to topically applied products is common and can limit the use of dermatological or cosmetic products. The purpose of this study was to evaluate the use of human skin equivalents (HSE) based on immortalised skin keratinocytes and evaluate the potential of a 22-gene panel in combination with multivariate analysis to discriminate between chemicals known to act as irritants and those that do not. Test compounds were applied topically to full thickness HSE or human ex vivo skin and gene signatures determined for known irritants and non-irritants. Principle component analysis showed the discriminatory potential of the 22-gene panel. Linear discrimination analysis, performed to further refine the gene set for a more high-throughput analysis, identified a putative seven-gene panel (IL-6, PTGS2, ATF3, TRPV3, MAP3K8, HMGB2 and MMP-3) that could distinguish potential irritants from non-irritants. These data offer promise as an in vitro prediction tool, although analysis of a large chemical test set is required to further evaluate the system.