Epidermal tight junctions in health and disease

• Published in: Tissue barriers Vol. 3; no. 1-2; p. e974451
• Main Authors: Brandner, JM, Zorn-Kruppa, M, Yoshida, T, Moll, I, Beck, LA, De Benedetto, A
• Format: Journal Article
• Language: English
• Published: United States Taylor & Francis 01-01-2015
• Subjects: AD, atopic dermatitis; AMP, antimicrobial peptides; claudins; Cldn, claudin; DC, dendritic cells; FLG, filaggrin; JAM, junctional adhesion molecule; LC, Langerhans cells; MM, malignant melanoma; PRR, pattern recognition receptor; PS, psoriasis; Review; SCC, squamous cell carcinoma; SC, stratum corneum; SG, stratum granulosum; skin barrier; skin immune system; skin innate barrier; SNP, single nucleotide polymorphism; TER, TransEpithelial Electrical Resistance; Th, T helper; tight junction; TJ, tight junction; TLR, Toll-like receptor; ZO-1, zonula occludens 1; TJ, tight junction; skin barrier; TLR, Toll-like receptor; FLG, filaggrin; Th, T helper; JAM, junctional adhesion molecule; AD, atopic dermatitis; Cldn, claudin; LC, Langerhans cells; SCC, squamous cell carcinoma; SC, stratum corneum; SNP, single nucleotide polymorphism; AMP, antimicrobial peptides; TER, TransEpithelial Electrical Resistance; PS, psoriasis; skin immune system; ZO-1, zonula occludens 1; PRR, pattern recognition receptor; SG, stratum granulosum; claudins; DC, dendritic cells; tight junction; MM, malignant melanoma; skin innate barrier
• ISSN: 2168-8362; 2168-8370; 2168-8370
• DOI: 10.4161/21688370.2014.974451

The skin, the largest organ of the body, is an essential barrier that under homeostatic conditions efficiently protects and/or minimizes damage from both environmental (e.g. microorganisms, physical trauma, ultraviolet radiation) and endogenous (e.g., cancers, inflammation) factors. This formidable barrier function resides mainly in the epidermis, a dynamic, highly-stratified epithelium. The epidermis has 2 major barrier structures: stratum corneum, the outmost layer and tight junctions, intercellular junctions that seal adjacent keratinocytes in the stratum granulosum, found below the stratum corneum.
In recent years there have been significant advances in our understanding of tight junction function, composition and regulation. Herein we review what is known about tight junctions in healthy skin and keratinocyte culture systems and highlight the dynamic crosstalk observed between tight junctions and the cutaneous immune system. Finally we discuss the preliminary observations suggesting that tight junction function or protein expression may be relevant for the pathogenesis of a number of common cutaneous inflammatory and neoplastic conditions.