Determination of Chemical Irritation Potential Using a Defined Gene Signature Set on Tissue-Engineered Human Skin Equivalents

Amy L Harding,Craig Murdoch,Simon Danby,Md Zobaer Hasan,Hirofumi Nakanishi,Tetsuo Furuno,Sirwan Hadad,Robert Turner,Helen E Colley

doi:10.1016/j.xjidi.2021.100011

Abstract

There are no physical or visual manifestations that define skin sensitivity or irritation; a subjective diagnosis is made on the basis of 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 based on immortalized 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 human skin equivalent or human ex vivo skin and gene signatures determined for known irritants and nonirritants. 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 matrix metalloproteinase gene MMP-3) that could distinguish potential irritants from nonirritants. 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.

Highlights

Skin sensitivity or irritation can be induced by exposure to exogenous stimuli that can be physical, in the form of UV light and wind; environmental, such as atmospheric pollutants; thermal, manifesting as heat or cold; or chemical entities, for example, constituents of cosmetics, Hþ ions, and drugs (Talagas and Misery, 2019)
Epithelial vacuolation was observed in the stratum spinosum of human skin equivalent (HSE), but this was less obvious in ex vivo skin (Figure 1e and f)
Ex vivo skin showed no histological changes on treatment of cocamide diethanolamine (Co-DEA), whereas HSE displayed occasional vacuolation in the stratum spinosum (Figure 1i and j)

Summary

Introduction

Skin sensitivity or irritation can be induced by exposure to exogenous stimuli that can be physical, in the form of UV light and wind; environmental, such as atmospheric pollutants; thermal, manifesting as heat or cold; or chemical entities, for example, constituents of cosmetics, Hþ ions, and drugs (Talagas and Misery, 2019). The topical application of dermatological agents that cause adverse skin sensitivity or irritation is a common reason for poor treatment compliance and can restrict therapeutic options. Received 11 January 2021; revised February 2021; accepted February 2021; accepted manuscript published online 15 March 2021; corrected proof published online 23 April 2021 The molecular mechanism for both skin sensitivity and irritation is still poorly defined and is likely to consist of interplay between keratinocytes (KCs) and dermal fibroblasts, which constitute the main mass of cells in the skin, along with other cell types from the neuronal and immune lineage

Objectives

Methods

Results

Conclusion