Abstract
The basement membrane (BM) at the dermal-epidermal junction (DEJ) plays important roles in cutaneous homeostasis by regulating information between epidermis and dermis. However it is not clear that the functional alteration of the BM by UV irradiation induces various changes in the dermis and epidermis. Since heparan sulfate at the BM regulates diffusion of several growth factors between epidermis and dermis by binding them, heparanase is known to be a degrading heparin sulfate at the BM, leading to deterioration in the function of the BM by diffusion of several growth factors. Thus, our purpose of this study is to elucidate the functional role of heparanase on the BM in the photo-aging process. Human heparanase was detected and activated in the epidermis, and degraded heparan sulfate in the BM at the DEJ by UVB irradiation. Furthermore, heparan sulfate at the DEJ plays important roles in maintaining epidermal differentiation and the structure of the BM. Therefore, we have identified for the first time that heparanase is a photo-aging enzyme that deteriorates the function of the BM by degrading the heparan sulfate chains, resulting in alteration of the dermis and epidermis, leading to photo-aging in UVB irradiated skin. For anti-aging and anti-wrinkle skincare, it is proposed that controlling heparanase activity would be an effective means of treatment. By using a screening system, it was determined that Sapindus mukurossi peel extract effectively inhibited heparanase activity.
