Modelling the human epidermis in vitro: tools for basic and applied research

Abstract

Culture models of tissues and organs are valuable tools developed by basic research that help investigation of the body functions. Modelling is aimed at simplifying experimental procedures in order to better understand biological phenomena, and consequently, when suYciently characterized, culture models can also be utilized with high potential in applied research. In skin biology and pathology, the development of cultures of keratinocytes as monolayers has allowed the elucidation of most functional and structural characteristics of the cell type. Beside the multiple great successes that have been obtained with this type of culture, this review draws attention on several neglected characteristics of monolayer cultures. The more sophisticated models created in order to reconstruct the fully diVerentiated epidermis have followed the monolayers. The epidermal reconstruction produces all typical layers found in vivo and thus makes the model much less simple, but only this kind of model allows the study of full diVerentiation in keratinocyte and production of the corniWed barrier. In addition to its interest in basic research, the reconstructed epidermis is currently gaining a lot of interest for applied research, particularly as an alternative to laboratory animals in the chemical and cosmetic industry. Today several commercial providers propose reconstructed skin or epidermis, but in vitro assays on these materials are still under development. In order to be beneWcial at long term, the validation of assays must be performed on a material whose availability will not be interrupted. We warn here providers and customers that the longevity of in vitro assays will be guaranteed only if these assays are done with welldescribed models, prepared according to published procedures, and must consider having a minimum of two independent simultaneous producers of similar material.

Deficiency of IL-22 Contributes to a Chronic Inflammatory Disease: Pathogenetic Mechanisms in Acne Inversa

“…We therefore analyzed the regulation of AMP expression by these cytokines in vitro and in vivo. As expected, treatment of RHE, an in vitro model mimicking human skin (35), with IL-22 or IL-20 resulted in a strong upregulation of BD1, BD2, BD3, S100A7, S100A8, and S100A9 mRNA (Fig. 4A), which was confirmed at the protein level for BD2 (Fig.…”

Non-animal models of epithelial barriers (skin, intestine and lung) in research, industrial applications and regulatory toxicology

“…Other limitations of ex vivo absorption studies are as follows: i) The receptor fluid may influence the transfer of the Gene knock-down tissues, reporter tissues, wound models and models populated with various pathogens have also been described in the literature (Geer et al, 2004;Jansson et al, 1996;Kuchler et al, 2011;Popov et al, 2014;Poumay and Coquette, 2007;Zhai et al, 2007;van Drongelen et al, 2013). Reconstructed human skin models for therapeutic purposes (grafting) have additionally been described since the 1970s, several of which have been commercialized (Tab.…”

Novel Tissue Types for the Development of Genomic Biomarkers

“…Synthetic skin is a relatively new surrogate tissue that lends itself to investigation of a wide variety of processes while reducing the need for volunteer recruitment or laboratory animal testing (Poumay & Coquette, 2007). For extracting nucleic acids, we have found that synthetic skin is less susceptible to nucleic acid degradation and more easily homogenized than real human skin (data not shown).…”