Melanin Photosensitization and the Effect of Visible Light on Epithelial Cells

Autor(es):Mostrar menos -

Chiarelli-Neto, Orlando ^[1] ; Ferreira, Alan Silva ^[1] ; Martins, Waleska Kerllen ^[1] ; Pavani, Christiane ^[1] ; Severino, Divinomar ^[1] ; Faiao-Flores, Fernanda ^[2] ; Maria-Engler, Silvya Stuchi ^[2] ; Aliprandini, Eduardo ^[3] ; Martinez, Glaucia R. ^[3] ; Di Mascio, Paolo ^[1] ; Medeiros, Marisa H. G. ^[1] ; Baptista, Mauricio S. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Dept Quim, Inst Quim, Sao Paulo - Brazil

^[2] Univ Sao Paulo, Fac Ciencias Farmaceut, Dept Analises Clin, BR-09500900 Sao Paulo - Brazil

^[3] Univ Fed Parana, Setor Ciencias Biol, Dept Bioquim & Biol Mol, BR-80060000 Curitiba, Parana - Brazil

• Tipo de documento: Artigo Científico
• Fonte: PLoS One; v. 9, n. 11 NOV 18 2014.
• Citações Web of Science: 42

Resumo

Protecting human skin from sun exposure is a complex issue that involves unclear aspects of the interaction between light and tissue. A persistent misconception is that visible light is safe for the skin, although several lines of evidence suggest otherwise. Here, we show that visible light can damage melanocytes through melanin photosensitization and singlet oxygen (O-1(2)) generation, thus decreasing cell viability, increasing membrane permeability, and causing both DNA photo-oxidation and necro-apoptotic cell death. UVA (355 nm) and visible (532 nm) light photosensitize O-1(2) with similar yields, and pheomelanin is more efficient than eumelanin at generating O-1(2) and resisting photobleaching. Although melanin can protect against the cellular damage induced by UVB, exposure to visible light leads to pre-mutagenic DNA lesions (i.e., Fpg- and Endo III-sensitive modifications); these DNA lesions may be mutagenic and may cause photoaging, as well as other health problems, such as skin cancer. (AU)

• Processo FAPESP: 10/08796-0 - Foto-irradiaçao e dano celular: correlação entre a quantidade de espécies reativas e o tipo de resposta de células epiteliais
• Beneficiário: Orlando Chiarelli Neto
• Linha de fomento: Bolsas no Brasil - Doutorado
• Processo FAPESP: 13/07937-8 - Redoxoma
• Beneficiário: Ohara Augusto
• Linha de fomento: Auxílio à Pesquisa - Centros de Pesquisa, Inovação e Difusão - CEPIDs
• Processo FAPESP: 12/50680-5 - Fotossensibilização nas ciências da vida
• Beneficiário: Mauricio da Silva Baptista
• Linha de fomento: Auxílio à Pesquisa - Temático