Role of Tight Junctions and Their Protein Expression in Atopic Dermatitis

Abstract. Atopic dermatitis (AD) is a chronic inflammatory skin disease with xerosis, itchiness, as well as interconnection with immunoglobulin E (Ig E), mediated foods including airborne allergies. AD is not only related to the diminished stratum corneum barrier but also presents with an unusual expression of tight junctions (TJs) proteins. TJ barrier dysfunction leads to impairment in the stratum corneum (SC) barrier. The significant role of TJs in the epidermal barrier as indicated by Claudin-1 (Cldn-1) deficient mice that undergo high transepidermal water loss (TEWL) and skin dehydration. In atopic dermatitis, downregulation of Cldn-1 was observed due to inflammation. Still, a lack of distinct understanding exists in considering tight junction barrier impairment as a cause or outcome in atopic dermatitis. This review summarizes TJs main role in skin barrier function and TJ proteins (TJPs) expression observed in AD patients.