Antioxidant Modifies the Stress Response of Human Cell Lines to UVB Irradiation

Increased expression of a specific set of genes as a consequence of extracellular stress is typically observed in all organisms. Heat shock proteins (hsps) are a set of evolutionarily conserved proteins, some constitutively expressed and others induced in response to physiological and environmental stressors. UVB has been reported to initiate a variety of hsp expression in mouse keratinocytes, as well as the induction of hsp72 in cultured human fibroblasts and keratinocytes. This stress response may be extremely important in the protection of human skin from UV-induced injury, typically seen as part of the ageing process. The ability of UVB to induce the expression of hsps in human skin cells is important because these proteins are critical for the survival of cells exposed to a variety of environmental stresses. In particular, a suboptimal stress response in skin cells may predispose skin to melanoma development and photoageing. Seen in this light, heat shock protein function offers a potential therapeutic target for modulation of UV-irradiation mediated skin carcinogenesis and photoageing.