Expression patterns of common hair follicle keratins in hair cycle

Abstract

Objective To evaluate the expression patterns of common hair follicle keratins in the hair follicle stages. Methods The mouse skins at different hair follicle stages including hair follicle morphogenesis, anagen onset, anagen, catagen, and telogen were harvested and embedded in paraffin. The sections were stained with anti-Krt5, anti-Krt6, anti-Krt10, anti-Krt14, anti-Krt15, and anti-Krt19 by immunostaining. Results Krt5 was expressed in the hair follicle epithelial of telogen and anagen stages. Krt6 was expressed in the outer root sheath and inner root sheath cells of hair follicles in all stages. Krt10 was expressed in the matrix and inner root sheath of anagen and catagen stages. Krt14 was expressed in the hair follicle epithelial of anagen and telogen stages. Krt15 and Krt19 were expressed in the bulge cells of morphogenesis, anagen onset, and telogen stages. Conclusion The keratins can only be used as hair structure or hair follicle stem cell markers at specific hair follicle stages. Researchers should determine the expression pattern of the hair follicle keratins in all hair follicle stages before using them as potential markers. Key words: Keratins; Hair follicle; Hair cycle; Immunofluorescence