| Summary: | 碩士 === 靜宜大學 === 化粧品科學系 === 106 === Ultraviolet (UV) radiation may cause sunburn, skin aging, and even result in skin cancer. Therefore, using sunscreens is one of strategies to reduce skin damage caused by UV rays. Chemical UV filters can prevent skin injury by absorbing UV rays. However, these chemical organic molecules, after contact with the skin, may infiltrate into the skin as a hapten and bind to their own proteins to produce a hapten-carrier complex with an antigenic effect. The hapten-carrier complex activated toll-like receptor (TLR), and then resulted in allergic contact dermatitis. Hyaluronan is one of the main components of extracellular matrix and its basic structure is glycosaminoglycans composed of D-glucuronic acid and N-acetylglucosamine. Hyaluronan are mainly synthesized from fibroblasts and keratinocytes. Previous studies have shown that low molecular weight hyaluronan is involved in the regulation of signal transduction of inflammatory response. Therefore, the roles of chemical UV filters in the production of hyaluronan and inflammatory events were studied in human keratinocytes. The expression of TLR and hyaluronan receptors were estimated by real-time PCR and western blots. Results showed that the four chemical UV filters reduced the extracellular content of hyaluronan but have no significant effect on the IL-18 production. In addition, octocrylene (Octo) and octyl methoxycinnamate (OMC) significantly stimulated the mRNA expression of TLR-2 and TLR-4 in human keratinocytes. Benzophenone-3 (Ben-3) led to a significant increase in CD44 mRNA expression. Ben-3, Octo and OMC significantly reduced the mRNA expression of RHAMM. Taken together, these data suggest that chemical UV filters could regulate the constituent of hyaluronan in human keratinocytes.
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