Delineation of Matriptase Protein Expression by Enzymatic Gene Trapping Suggests Diverging Roles in Barrier Function, Hair Formation, and Squamous Cell Carcinogenesis

The study investigated the role of the membrane serine protease matriptase in mice, focusing on its involvement in epidermal barrier function, hair formation, and squamous cell carcinogenesis. Matriptase was essential for terminal differentiation in various epithelial tissues and was crucial for epidermal barrier formation and hair follicle development, with deficiencies leading to impaired skin lipid formation and hair follicle hypoplasia. It was also implicated in squamous cell carcinoma, as overexpression in transgenic mice initiated carcinogenesis. The study used gene trapping techniques to map matriptase expression, revealing its presence in keratinized stratified epithelium, hair follicles, and epidermal carcinomas, suggesting diverse roles in tissue development and cancer progression. Despite its critical roles, matriptase-deficient hair follicles responded similarly to exogenous growth factors, indicating a complex role in hair growth regulation.