An Inflamed and Infected Reconstructed Human Epidermis to Study Atopic Dermatitis and Skin Care Ingredients.

Area of Science:

• Dermatology
• Microbiology
• Immunology

Background:

• Atopic dermatitis (AD) is a complex inflammatory skin condition.
• Epidermal barrier dysfunction and microbial imbalance, particularly Staphylococcus aureus colonization, worsen AD.
• Existing in vitro models do not fully replicate AD's multifaceted pathology.

Purpose of the Study:

• To develop a more comprehensive in vitro model of atopic dermatitis.
• To investigate the interaction between Staphylococcus aureus and an inflamed epidermis.
• To evaluate the therapeutic potential of Castanea sativa extract in an AD model.

Main Methods:

• Developed a reconstructed human epidermis (RHE) model.
• Exposed RHE to a Th2 pro-inflammatory cytokine cocktail and Staphylococcus aureus.
• Assessed physical, microbial, and immune alterations.
• Evaluated the effect of Castanea sativa extract on AD-like phenotypes and S. aureus.

Main Results:

• The RHE model successfully replicated key AD features, including physical, microbial, and immune disruptions.
• Staphylococcus aureus exhibited increased virulence when the epidermis was exposed to inflammatory cytokines.
• Castanea sativa extract application prevented AD-like phenotypes by enhancing epidermal barrier proteins (filaggrin, claudin-1, loricrin) and inhibiting S. aureus virulence factors (biofilm, enzymes, inflammatory potential).

Conclusions:

• The developed RHE model provides a valuable tool for studying atopic dermatitis pathogenesis.
• Staphylococcus aureus virulence is amplified in an inflammatory skin environment, contributing to chronic AD.
• Castanea sativa extract demonstrates therapeutic promise for atopic dermatitis by restoring barrier function and mitigating bacterial virulence.