In vitro cell bioassays of complex skin disorders to evaluate dermocosmetic bioactives: psoriasis model

Psoriasis is a chronic immune-mediated inflammatory disease that affects 2-3% of worldwide population. The abnormal behaviour of psoriatic keratinocytes results in a different pattern of gene and protein expression than healthy skin cells. Considering the current framework of the Cosmetic Testing Regulation in Europe, in vitro models have evolved to a valuable tool not only to test the efficacy of cosmetic bioactives but also to improve understanding of skin physiopathology. The knowledge of molecular signalling of psoriasis can be used to develop tailored in vitro cell bioassays of this complex disease. Based on the molecular basis of the disease AINIA aimed at developing an in vitro cell model of psoriasis. For that, primary human keratinocytes in a high-throughput platform were exposed to a fit-of-purpose cocktail of inflammatory cytokines, which are increased in psoriatic cells. Then, changes in specific gene biomarkers of psoriasis such as K10, K1, IL-23, SKALP/efalin and S100A7 were analyzed by real-time rt-PCR. Changes at the molecular level revealed increased expression levels of IL-23, SKALP, S100A7 and reduced levels of K10, K1, following the pattern of psoriatic cells. This miniaturized model of keratinocytes lets to evaluate if different bioactives, alone or in combination (synergism) with others, can mitigate the anomalous signalling of the psoriatic disorder, identifying potential therapy against specific psoriatic biomarkers.