From Blue Light to Clock Genes in Zebrafish ZEM-2S Cells

Autor(es)

Ramos, Bruno C. R. ^[1] ; Moraes, Maria Nathalia C. M. ^[1] ; Poletini, Maristela O. ^{[1, 2]} ; Lima, Leonardo H. R. G. ^[1] ; Castrucci, Ana Maria L. ^[1]

Afiliação do(s) autor(es)

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

^[2] Univ Fed Minas Gerais, Inst Biol Sci, Dept Physiol, Belo Horizonte, MG - Brazil

• Tipo de documento: Artigo Científico
• Fonte: PLoS One; v. 9, n. 9 SEP 3 2014.
• Citações Web of Science: 18

Resumo

Melanopsin has been implicated in the mammalian photoentrainment by blue light. This photopigment, which maximally absorbs light at wavelengths between 470 and 480 nm depending on the species, is found in the retina of all classes of vertebrates so far studied. In mammals, melanopsin activation triggers a signaling pathway which resets the circadian clock in the suprachiasmatic nucleus (SCN). Unlike mammals, Drosophila melanogaster and Danio rerio do not rely only on their eyes to perceive light, in fact their whole body may be capable of detecting light and entraining their circadian clock. Melanopsin, teleost multiple tissue (tmt) opsin and others such as neuropsin and va-opsin, are found in the peripheral tissues of Danio rerio, however, there are limited data concerning the photopigment/s or the signaling pathway/s directly involved in light detection. Here, we demonstrate that melanopsin is a strong candidate to mediate synchronization of zebrafish cells. The deduced amino acid sequence of melanopsin, although being a vertebrate opsin, is more similar to invertebrate than vertebrate photopigments, and melanopsin photostimulation triggers the phosphoinositide pathway through activation of a G(q/11)-type G protein. We stimulated cultured ZEM-2S cells with blue light at wavelengths consistent with melanopsin maximal absorption, and evaluated the time course expression of per1b, cry1b, per2 and cry1a. Using quantitative PCR, we showed that blue light is capable of slightly modulating per1b and cry1b genes, and drastically increasing per2 and cry1a expression. Pharmacological assays indicated that per2 and cry1a responses to blue light are evoked through the activation of the phosphoinositide pathway, which crosstalks with nitric oxide (NO) and mitogen activated protein MAP kinase (MAPK) to activate the clock genes. Our results suggest that melanopsin may be important in mediating the photoresponse in Danio rerio ZEM-2S cells, and provide new insights about the modulation of clock genes in peripheral clocks. (AU)

• Processo FAPESP: 11/23930-8 - Melanopsina em vertebrados não mamíferos: função e transdução do sinal luminoso
• Beneficiário: Leonardo Henrique Ribeiro Graciani de Lima
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Pós-Doutorado
• Processo FAPESP: 10/51374-0 - Efeito da luz e endotelina no mecanismo molecular do relogio em melanoforos de xenopus laevis
• Beneficiário: Maria Nathália de Carvalho Magalhães Moraes Figueira Borges
• Modalidade de apoio: Bolsas no Brasil - Doutorado