PAPEL DA CAVEOLINA-1 NO DESENVOLVIMENTO DA RETINA DE PINTO

• Autor(a) principal: Freitas, Rodrigo Cesar Carvalho
• Data de Publicação: 2009
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Federal Fluminense (RIUFF)
• Texto Completo: https://app.uff.br/riuff/handle/1/17251
• topic: Cavéolas; Retina animal; Pinto; Proliferação celular; Diferenciação celular; caveolina; Proteína; Caveolin Cell proliferation Cell differentiation caveolae; CNPQ::CIENCIAS BIOLOGICAS::IMUNOLOGIA

Caveolin-1 (cav -1) forms the caveolae and is involved in the regulation of cellular differentiation and proliferation. In this work, we studied the cav-1 expression, as well as its function during the development of the chick retina. Experiments of "western blotting" revealed that cav-1 expression in retinal cultures was very reduced in the beginning of the culture, increased after the day 3 (E8C3) and attained maximal levels at E9C9. This increase was also observed during the development "in vivo" of the retina. Immunofluorescence (IF) for cav-1 was not observed in positive cells for BrDU in E8C1. In the same way, no If for BrDU was found in cav-1 positive cells of E8C8, suggesting that the cav-1 expression was just found in post- mitotic glial cells. Hydrocortisone (HC) was capable of inhibiting the proliferation of glial progenitors induced by ATP in cultures of E8C1-2. This hormone was also capable of inhibiting ADPdependent activation of ERK in young cultures (E8C1), but not in more differentiated cultures (E8C6). Moreover, the expression of P2Y1 receptors was only observed in cultures of E8C1, but not in cultures of E8C8, suggesting that the expression of these receptors can be modulated during development. On the other hand, cav-1 expression was inhibited by PD 98059, an ERK inhibitor, suggesting that the expression of this protein is dependent on the activation of this signalling pathway. HC inhibited cav-1 expression at initial stages of the cultures (E8C0-C4), but not at more differentiated stages. Moreover, the removal of HC after 72 hours of treatment of young cultures favored the cellular proliferation induced by ATP in a more advanced period of the cultures (E8C4). Once cav-1 expression was inhibited by HC in this condition, these data suggest that the absence of this protein maintains the glial precursors susceptible to ATP in proliferative state, in a post proliferation period of development.