Life before and beyond blistering: The role of collagen XVII in epidermal physiology

• Published in: Experimental dermatology Vol. 28; no. 10; pp. 1135 - 1141
• Main Authors: Natsuga, Ken, Watanabe, Mika, Nishie, Wataru, Shimizu, Hiroshi
• Format: Journal Article
• Language: English
• Published: Denmark Wiley Subscription Services, Inc 01.10.2019
• Subjects: Adherens Junctions - pathology; Autoantibodies - immunology; Autoantigens - genetics; Autoantigens - immunology; Autoantigens - physiology; Autoimmunity; Bullous pemphigoid; Cell Line; Cell proliferation; Cell-Derived Microparticles - chemistry; COL17A1; Collagen; Collagen Type XVII; collagen XVII; epidermal stem cells; Epidermis; Epidermis - pathology; Epidermolysis bullosa; Epidermolysis Bullosa, Junctional - genetics; Epidermolysis Bullosa, Junctional - pathology; Extracellular Matrix Proteins - physiology; Forecasting; Hemidesmosomes; Hemidesmosomes - metabolism; Hemidesmosomes - ultrastructure; Humans; Junctional epidermolysis bullosa; Keratinocytes; Keratinocytes - metabolism; Non-Fibrillar Collagens - genetics; Non-Fibrillar Collagens - immunology; Non-Fibrillar Collagens - physiology; Pemphigoid, Bullous - immunology; Protein Domains; Signal Transduction; Stem Cell Niche; Stem cells; COL17A1; bullous pemphigoid; epidermal stem cells; collagen XVII; epidermolysis bullosa
• ISSN: 0906-6705; 1600-0625
• DOI: 10.1111/exd.13550

Type XVII collagen (COL17) is a transmembranous protein that is mainly expressed in the epidermal basal keratinocytes. Epidermal‐dermal attachment requires COL17 expression at the hemidesmosomes of the epidermal basement membrane zone because congenital COL17 deficiency leads to junctional epidermolysis bullosa and acquired autoimmunity to COL17 induces bullous pemphigoid. Recently, in addition to facilitating epidermal‐dermal attachment, COL17 has been reported to serve as a niche for hair follicle stem cells, to regulate proliferation in the interfollicular epidermis and to be present along the non‐hemidesmosomal plasma membrane of epidermal basal keratinocytes. This review focuses on the physiological properties of COL17 in the epidermis, its role in maintaining stem cells and its association with signalling pathways. We propose possible solutions to unanswered questions in this field.