VEGFR-2 Is in a State of Activation in Hair Follicles, Sebaceous Glands, Eccrine Sweat Glands, and Epidermis from Human Scalp: An In Situ Immunohistochemistry Study of Phosphorylated VEGFR-2

BACKGROUND Recent research reports that VEGFR-2 is expressed in the whole hair follicle, sebaceous glands, eccrine sweat glands, and epidermis. However, phosphorylated VEGFR-2 was not found, and it could not be ascertained whether the activated form of VEGFR-2 actually participates in the biological control of epidermal appendages. In this study we aimed to determine whether the VEGFR-2 pathway is directly involved in the daily regulation of epidermal appendages biology. MATERIAL AND METHODS In this study, we investigated the expression of phosphorylation of VEGFR-2 by immunohistochemical analysis in the epidermis and epidermal appendages in normal human scalp skin. RESULTS Immunohistochemical analysis revealed phosphorylation of VEGFR-2 in a whole hair follicle, mainly in the infundibulum basal layer, hair cortex, and medulla in the isthmus, and matrix in the hair bulb. Phosphorylated VEGFR-2 also was found in the sebaceous glands, eccrine sweat glands, and epidermis. CONCLUSIONS Therefore, we suggest that VEGFR-2 activation is involved in routine regulation of human epidermal appendages.