EXPRESSÃO DE P27/KIP1 NO DESENVOLVIMENTO DE RETINAS DE GALINHA

• Ano de defesa: 2009
• Autor(a) principal: Portugal, Liana Catarina Lima
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Programa de Pós-graduação em Neuroimunologia; Neuroimunologia
• Palavras-chave em Português: PK27; KIp1; Proteína; Ciclo celular; Retina animal; retina de galinha; P27; cell cycle; protein; CNPQ::CIENCIAS BIOLOGICAS::IMUNOLOGIA
• Link de acesso: https://app.uff.br/riuff/handle/1/18530

P27/Kip1 is a protein that inhibits cell cycle and that is also involved in cell migration and differentiation. In the present work, we characterized the expression and localization of p27/Kip1 during the development of the chick retina in vivo and in vitro. The expression of p27/Kip1 was analysed by western blotting and immunocytochemistry. P27/Kip1 content in retinal monolayer cultures obtained from 7- day-old chick embryos increased during cell differentiation in the cultures. The expression of this protein increased after culture day 2 (C2) (163 ± 9,9% of the expression in C0, n=7), attaining the maximal level of expression of 261 ± 14,4% (n=4) in C4. This level of expression was constant until C9 (273 ± 15,8%, n=4). Immunoreactivity for p27/Kip1 (IR) was observed only in neurons until C7. During the in vivo ontogeny, the expression of this protein was maximal in retinas from E12 embryos and, although decreasing by 30% after this stage, p27/Kip1 levels remained high until the adult period. High IR was observed in cell bodies located in the future ganglion cell layer at the beginning of development. As ontogeny proceedes, 2 populations with different labeling intensities were detected. The IR of low intensity was observed in some elongated neuroblasts located in the future nuclear layers. The high intensity IR was detected in more differentiated cell bodies and in migrating cell bodies in the Inner Plexiform Layer. During synaptogenesis, labeled processes of cells located in the ganglion cell layer and amacrines, directed to the Inner Plexiform Layer were identified. In retinas from 60-day-old animals, high IR was observed in part of the cell bodies from all the layers of the tissue, except in the cell bodies of glial cells (n=5). Our data indicate tha p27/Kip1 is involved in the processes of cell cycle exit, differentiation and migration during development. Its presence in the adult retina suggests that it has a role in the mantainance of the cell differentiated state in this tissue.