| abstract |
The deleterious effects of the passage of time on human skin (i.e., chronological aging of human skin) can be prevented and treated with the topical application of a retinoid, preferably retinol. We have found that some of the same pathways (namely the stress-activated pathways, SAPs) activated in photoaging of human skin (i.e., sun-induced premature skin aging) are similarly elevated in the skin of elderly people. We have also found that other pathways (namely the mitogen-activated ERK pathway) is depressed in the same skin. Treatment of chronologically-aged skin with a retinoid both inhibits degradation of dermal collagen and promotes procollagen synthesis. Biopsied sections from skin of elderly (80+ years old) show that a single treatment can increase epidermal thickness, improve the dermal collagen density, and promote the formation of rete pegs and dermal papillae (see Fig. 13), and can decrease the amount of c-Jun and increase the amounts of Types I and III procollagen (see Fig. 18). Such benefits are also helpful in preventing bruising, tearing, and ulceration of elderly skin. |