IGF-I aumenta a proliferação de células da retina em cultura: vias de sinalização envolvidas

• Autor(a) principal: Medina, Simone Vidal
• 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/1/18421
• topic: retina animal; acetilcolina; receptores muscarínicos; M1; neurotransmissor; neurotrofinas.; Fator de crescimento; Proliferação celular; animal retina; acetylcholine; muscarinic receptors; M1; neurotransmitter; neurotrofines.; growth factor; cell proliferation; CNPQ::CIENCIAS BIOLOGICAS::IMUNOLOGIA

IGF-I is a growth factor playing a role in cell survival, cell proliferation and cell differentiation. The purpose of this work was to study, in vitro, the effect of IGF-I on retinal cell proliferation. Our results show that treatment with IGF-I induces a 50% increase in cellular proliferation. This effect was dose and time dependent. The greater response was obtained with 10ng/mL IGF-I after 24-48h in culture. However after 72h, cultures treated with IGF-I did not exhibit an increase in cell proliferation. The effect of IGF-I involves the stimulation of several intracellular pathways including activation of PI-3 kinase, phospholipase C, PKC d, MAPK, JNK and Src. Our results suggest that following IGF-I treatment the metalloproteinase 9 and EGF receptors are stimulated. When we either blocked the vesicular release of polypeptides or the internalization of membrane receptors the effect of IGF-I was inhibited. Taken together our results show that the proliferative effect of IGF-I depends on the activation of EGF receptors and on the activation of distinct intracellular pathways. Since the IGF-I effect was observed only during the first 48h in culture we may suggest a regulatory role of this trophic factor in the control of cellular proliferation of retinal cells.