betadex and Dermatitis--Atopic

Topics: beta-Cyclodextrins; Carbonic Anhydrase II; Cytokines; Dermatitis, Atopic; Epidermis; Filaggrin Proteins; Gene Expression; Humans; Hyaluronan Synthases; Hyaluronic Acid; Interleukin-13; Interleukin-17; Interleukin-4; Interleukins; Intermediate Filament Proteins; Membrane Proteins; Nerve Tissue Proteins; Skin Physiological Phenomena; Thymic Stromal Lymphopoietin

Atopic dermatitis (AD) skin is characterized by over-expression of interleukin (IL)-4, IL-13 and IL-25. When methyl-β-cyclodextrin (MβCD) treatment preceded exposure to these interleukins, combination of both treatments was found to mimic hallmarks of AD in vitro, such as barrier weakening, histological alterations and typical signaling responses in a reconstructed human epidermis (RHE). However, the respective role of each IL and whether any of them is critical when combined with MβCD treatment was unknown. Therefore, this work aimed to distinguish RHE responses after exposure to MβCD and each one of the three IL reported to mimic typical features of AD. IL-4 incubation preceded by MβCD was found responsible for altered histology, as well as for barrier alterations, evidenced by electrical resistance and dye permeation measurements. This combination further decreased loricrin (LOR) immunoreactivity, whereas mainly IL-25, combined to MβCD treatment, was able to downregulate filaggrin (FLG) mRNA level. Carbonic anhydrase II (CA2) and hyaluronan synthase 3 (HAS3), two other markers up-regulated in AD, were also induced when MβCD treatment was followed by IL-4, whilst the expression of neural epidermal growth factor-like 2 (NELL2) was up-regulated by paired IL-4 and IL-13. In conclusion, multiple features of AD were found in this in vitro model mainly when treatment of RHE by IL-4 was conducted after preliminary MβCD incubation.

Topics: beta-Cyclodextrins; Carbonic Anhydrase II; Cell Shape; Cells, Cultured; Dermatitis, Atopic; Electric Impedance; Epidermis; Filaggrin Proteins; Gene Expression Regulation; Humans; Interleukin-4; Keratinocytes; Membrane Proteins; Permeability; RNA, Messenger; Signal Transduction

Transient cholesterol depletion from plasma membranes of human keratinocytes has been shown to reversibly activate signalling pathways in monolayer cultures. Consecutive changes in gene expression have been characterized in such conditions and were interestingly found to be similar to transcriptional changes observed in keratinocytes of atopic dermatitis (AD) patients. As an inflammatory skin disease, AD notably results in altered histology of the epidermis associated with a defective epidermal barrier. To further investigate whether the activation of keratinocytes obtained by cholesterol depletion could be responsible for some epidermal alterations reported in AD, this study was undertaken to analyse cholesterol depletion in stratified cultures of keratinocytes, i.e. a reconstructed human epidermis (RHE). RHE contains heterogeneous populations of keratinocytes, either proliferating or progressively differentiating and stratifying towards the creation of a cornified barrier. Cholesterol depletion induced in this model was found reversible and resulted in activation of signalling pathways similar to those previously identified in monolayers. In addition, selected changes in the expression of several genes suggested that keratinocytes in RHE respond to cholesterol depletion as monolayers. However, preserved histology and barrier function indicate that some additional activation, likely from the immune system, is required to obtain epidermal alterations such as the ones found in AD.

Topics: beta-Cyclodextrins; Blotting, Western; Cells, Cultured; Cholesterol; Dermatitis, Atopic; Epidermis; Humans; Keratinocytes; Real-Time Polymerase Chain Reaction