Research project
Atopic eczema
Atopic eczema (AE) is the most common pruritic chronic inflammatory skin disease occurring especially in children. Increasing evidence shows that the disease may be initiated by a defective barrier function of the stratum corneum (SC), the upper layer of the skin, leading to increased transepidermal water loss (TEWL) and susceptibility to penetration of harmful substances. This triggers a TH2 immune response that further elevates the degree of barrier dysfunction. Filaggrin, a SC protein is involved in terminal differentiation of keratinocytes. Loss-of-function mutations in filaggrin, have shown to be present in 50% of AE patients.
Therefore, the purpose of this project is to generate and fully characterise a novel human skin equivalent (HSE) that closely mimic properties of AE skin. The derived AE HSEs serve as a tool to examine in detail the features of AE and the screening of drugs for AE treatment.
The SC consists of corneocytes and a lipid enriched inter-cellular domain. The inter-cellular lipid organization and composition plays a key role in the creation of the SC barrier which is disrupted in AE. In addition the role of filaggrin in the barrier function remains to be established. This project aims first to characterise the barrier parameters (including hydration and NMF levels) and barrier proteins (e.g. KLKs, filaggrin) in healthy and AE skin using explanted AE biopsy derived HSEs The obtained differences in barrier properties between healthy and AE skin will be used to generate the optimal AE HSE.
During HSE development, medium will be supplemented with inflammatory mediators to create optimal AE conditions. Alternatively, conditioned media obtained from lymphocytes or dendrtic cell line (MUTZ3) cultures will be used to culture the HSE. Furthermore, filaggrin will be knocked out in keratinocytes and important filaggrin mutations will be incorporated to mimic the AE phenotype. Finally, the different approaches will be combined to generate the most representative AE HSE. As a proof of principle, the AE HSE mimicking the AE phenotype best will be used for drug screening. Treated and untreated AE skin models will be fully characterized on epidermal morphogenesis and barrier properties.