Molecular Characterization of Inflammation and <i>Staphylococcus aureus</i> Colonization of Involved Skin of Atopic Dermatitis Patients

Abstract

Atopic dermatitis (AD) is a multifactorial chronic inflammatory disease mainly stemming from a genetic predisposition that leads to hypersensitivity to environmental factors and a common involvement of Staphylococcus aureus (SA) colonization. The aim of this work was to propose a new non-invasive approach to enumerate the genes coding for the toxins of SA in atopic skin samples. In parallel, the study aimed to evaluate the change in AD through 3 markers of the inflammatory response: IL-8, IL-1RA/IL-1α and IL-18. These methods were tested on 31 patients with AD, and finally on a group of 19 subjects for whom clinical improvement had been reported after various treatments. The study revealed the presence of a large number of genes encoding toxins in atopic samples, indicating a high rate of SA colonization, and also an increase in the level of all cytokine markers in atopic skin compared to the skin of healthy subjects. Finally, we found a positive correlation between increases in the SCORAD (Scoring Atopic Dermatitis Index) value after treatment and the corresponding evolution of the SA density. These methods provide a means to clinically evaluate the course of AD, and may help in the development of potential treatments.

Anti-inflammatory and immunomodulatory effects of <em>Aquaphilus dolomiae</em> extract on in vitro models

“…Involucrin expression is significantly decreased in both acute and nonlesional skin of subjects with AD compared with skin from healthy subjects 15. Furthermore, all the inflammatory markers induced in the present in vitro model of stimulated NHK have been shown to be upregulated in AD, for example, TSLP and IL-18 cytokines 25,30…”

Quantification of Demodex folliculorum by PCR in rosacea and its relationship to skin innate immune activation

“…Moreover, to obtain data on the cascade of events occurring during rosacea, we have used assay methods that enabled us to collect mRNA of key genes from an epidermal extract obtained after micro‐abrasion and proteins on the skin surface (as IL‐8) by swabbing .…”

Reduced filaggrin expression is accompanied by increased Staphylococcus aureus colonization of epidermal skin models

“…Using full thickness skin models, S. aureus strain LUH14616 was shown to induce the release of the inflammatory chemokine IL-8 by epidermal keratinocytes [29]. Although no much is known about the role of IL-8 in AD, its up-regulation in AD was shown to be associated with the presence of S. aureus [16]. We have found that the S. aureus-induced IL-8 response by epidermal models was not affected by FLG-KD, but significantly enhanced following exposure to IL-31, suggesting that enhanced S. aureus colonization alone due to FLG-KD is not sufficient to evoke an inflammatory response and requires the presence of (AD-related) cytokines such as IL-31.…”