SATOSHI AMANO

Shiseido Research Centre, 2-2-1 Hayabuchi, Tsuzuki-ku, Yokohama, Japan

Abstract

For the skincare treatment to photoaging, the daily treatment should be important because our faces, hands and arms are usually exposed to air and sun directly. Ultraviolet (UV) exposure strongly influences skin aging (so-called photoaging). UVB penetrates papillary dermis and UVA does much deeper, and the UV light induces several kinds of skin damages some of which are shown in the paper. Sun-exposed skin shows not only superficial changes, such as wrinkles and sagging, but also many internal changes in the epidermis, basement membrane and dermis. In this paper, heparanase, laminin 5, Serpin b3, vascular endothelial growth factor (VEGF), thrombospondin-1 (TSP-1) and fibulin-5 are selected as the possible targets of daily skin care treatment for cutaneous photoaging.

ULTRASTRUCTURAL ALTERATION OF EPIDERMAL BASEMENT MEMBRANE (BM) AT THE DERMAL-EPIDERMAL (D-E) JUNCTION IN SUN-EXPOSED SKINS

The BM at the D-E junction has many functions, of which the most obvious is to tightly link the epidermis to the dermis (1). It also determines the polarity of the epidermis and provides a barrier against epidermal migration. Once the BM has been assembled, the epidermal cells recognize the surface adjacent to the BM as the basal surface. Stratification of the epidermis proceeds with the proliferating cells remaining attached to the BM and the daughter cells migrating into the upper layers (2). It is thought that the BM influences epidermal differentiation and maintains the proliferative state of the basal layer. Under normal circumstances, the BM prevents direct contact of epidermal cells with the dermis. Another important function of the BM derives from the positioning of the structure between the epidermal cells and the dermal cells. The epidermis and the dermis do not function independently (3). Instead, normal skin homeostasis requires the constant passage of signals back and forth between the two cell types. In general, these s ...