Performance of the N/TERT epidermal model for skin sensitizer 4 identification via Nrf2-Keap1-ARE pathway activation
Authors
Mariam Alloul-Ramdhani, Cornelis P. Tensen, Abdoelwaheb El Ghalbzouri
Institution
Leiden Uni
Country
Netherlands
Year
2014
Journal
Toxicology in Vitro
Abstract
Animal testing of chemical ingredients for cosmetic purposes is prohibited. Therefore there is an urgent 34
need for in vitro models to identify chemical allergens. In human skin, keratinocytes (KCs) are abundantly 35
present and are key players in initiation of allergic contact dermatitis. One of the pathways that has been 36
shown to be induced by sensitizers is the Keap1-Nrf2-ARE pathway. In this study we compared the 37
response of four keratinocyte-based models including (a) primary human KCs, (b) N/TERT monolayer cul- 38
tures, (c) the Leiden Epidermal models (LEMs) and (d) the N/TERT epidermal models (NEMs). All kerati- 39
nocyte-based models were subjected to chemical exposure of the sensitizer 2,4-dinitrochlorobenzene 40
(DNCB) and irritant Sodium dodecyl sulfate (SDS) at nontoxic concentrations. Activation of the Keap1- 41
Nrf2-ARE pathway was evaluated by measuring Nrf2 protein levels as well as nuclear translocation 42
and activation of transcriptional targets of Nrf2. Results show that the Keap1-Nrf2-ARE pathway is acti- 43
vated by the sensitizer DNCB in monolayer keratinocytes and as well as the LEMs and NEMs and not by 44
the irritant SDS. Collectively our data demonstrate that the N/TERT models respond similarly as primary 45
KCs and could therefore serve as an alternative model for skin sensitizer identification, thereby overcom- 46
ing the need for primary skin tissue.