In vitro reconstituted skin models: development, damage assessment and photoprotective efficacy in the UVA and visible spectral ranges

Abstract

The role of UVB in the development of skin cancer is very well documented. In contrast, the role of UVA still remains unclear and is controversial. This is partly due to the dual role of melanin, as both a photoprotector and a photosensitizer. It has been showed that the visible range can also interfere with the synthesis of melanin and promote skin damages. Therefore, this study aims to evaluate, on a pigmented reconstructed skin model, the effect of UVA and VIS radiation on the skin melanogenesis and, consequently, the role of melanin on DNA damage after radiation, as well as the effectiveness of UVA filters against this damage. Therefore, reconstituted skin models, containing or not human melanocytes will be developed, irradiated by increasing doses of UVA and VIS radiation and evaluated concerning the content and melanin transfer to keratinocytes, melanogenesis gene expression, cell death, oxidative stress, formation of photodimers and photooxidation lesions, as well as the oxidative damage caused to the DNA by flow cytometry, confocal microscopy, PCR and Western blot and the Comet assay. In addition, UVA filters will be evaluated for their ability to protect against the damages caused to DNA. With these results it is expected to establish the production of a pigmented reconstructed skin model and provide additional information on the influence of UVA and VIS radiation on skin melanogenesis and, consequently, the photosensitizing role of melanin and its implications on DNA damage. Finally, it is expected to contribute to the new solar photoprotection strategies being properly proposed.