RESUMO
We compared the expression of Sox2, Oct4, Nanog, Pax6, Prox1 genes associated with plasticity of neural stem and progenitor cells during human neocortex and retina development and in cell cultures. At the analyzed stages of neurogenesis, Pax6 gene is expressed in the neocortex and retina at constant levels, the expression is by one order of magnitude higher in the retina. The dynamics of Sox2 and Pax6 expression in the neocortex was similar. The expression of Oct4 and Nanog genes during neurogenesis in the neocortex and human fetal retina reflects the existence of a high-plasticity cell pool. The dynamics of ßIII-tubulin expression indicates that the retina develops more rapidly than the neocortex. Our experiments showed that genetically determined cell potencies typical of native cells are realized in primary cultures without specific stimulation.
Assuntos
Neocórtex/metabolismo , Células-Tronco Neurais/metabolismo , Retina/metabolismo , Células Cultivadas , Proteínas do Olho/metabolismo , Proteínas de Homeodomínio/metabolismo , Humanos , Proteína Homeobox Nanog , Fator 3 de Transcrição de Octâmero/metabolismo , Fator de Transcrição PAX6 , Fatores de Transcrição Box Pareados/metabolismo , Proteínas Repressoras/metabolismo , Fatores de Transcrição SOXB1/metabolismo , Proteínas Supressoras de Tumor/metabolismoRESUMO
Immunoperoxidase and molecular genetic analysis showed that retinal pigment epithelial cells from adult human eye undergo morphogenetic changes in vitro. They lose expression of tissue-specific protein RPE65 and start to express stem cell markers: Oct4 (POU5F1), Nanog, Prox1, Musashi 1, and Pax6, which indicates their differentiation. Expression of Musashi 1 and Pax6 attest to neural differentiation, which is also confirmed by the expression of ßIII-tubulin, a neuroblast marker, and markers of differentiated neuronal cells, tyrosine hydroxylase and neurofilament proteins. These findings attest to the capacity of retinal pigment epithelium from adult human eye to transdifferentiation into neural lineage cells, which makes them an interesting object for cell therapy in neurodegeneration.
Assuntos
Epitélio Pigmentado Ocular/metabolismo , Retina/metabolismo , Diferenciação Celular/genética , Diferenciação Celular/fisiologia , Células Cultivadas , Proteínas do Olho/genética , Proteínas do Olho/metabolismo , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Humanos , Imuno-Histoquímica , Proteína Homeobox Nanog , Fator 3 de Transcrição de Octâmero/genética , Fator 3 de Transcrição de Octâmero/metabolismo , Fator de Transcrição PAX6 , Fatores de Transcrição Box Pareados/genética , Fatores de Transcrição Box Pareados/metabolismo , Epitélio Pigmentado Ocular/citologia , Reação em Cadeia da Polimerase , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Retina/citologia , Proteínas Supressoras de Tumor/genética , Proteínas Supressoras de Tumor/metabolismo , cis-trans-Isomerases/genética , cis-trans-Isomerases/metabolismoRESUMO
Phenotypic plasticity of retinal pigment epithelial cells from adult human eye was studied by immunohistochemical methods under different culturing conditions. It was found that retinal pigment epithelium in adult human eye is a heterogeneous population of cells demonstrating different behavior in vitro. Some cells retain epithelial morphology for a long time in culture, while others are rapidly transformed into fibroblast-like cells and synthesize proteins typical of proneural, neural, glial, and photoreceptor cells. However, irrespective of initial morphological features differentiation of retinal pigment cells can be modulated by varying culturing conditions.
Assuntos
Plasticidade Neuronal , Epitélio Pigmentado da Retina/citologia , Adulto , Idoso , Diferenciação Celular , Humanos , Técnicas In Vitro , Pessoa de Meia-IdadeRESUMO
Expression of transforming growth factor-ß2 was detected by PCR in the vitreous body, lens, retina, and ciliary-iris complex of human eye at early stages of fetal development. Immunochemical assay of the corresponding protein in eye tissues revealed a correlation between the localization of transforming growth factor-ß2 and the development of intraocular hyaloid vascular network, its regression, formation of the vitreous body, and development of definite retinal vessels.
Assuntos
Olho/metabolismo , Fator de Crescimento Transformador beta2/metabolismo , Corpo Vítreo/metabolismo , Olho/embriologia , Humanos , Imunoquímica , Técnicas In Vitro , Reação em Cadeia da Polimerase , Retina/metabolismo , Fator de Crescimento Transformador beta2/genéticaRESUMO
Multipotent characteristics of human fetal (9-11.5 weeks) pigmented epithelial retinal cells and capacity to transdifferentiation in neuronal direction were studied in vitro under different culturing conditions. The cultures were analyzed using a wide spectrum of antibodies. It was found that pigmented epithelium of human eye is a heterogeneous cell population with three subtypes differing by adhesion characteristics, migration, transdifferentiation potential, and reaction to microenvironmental factors. Subtype 1 cells steadily retain their epithelial characteristics, subtype 2 cells change their morphotype and produce neuroblast and photoreceptor cell proteins, and subtype 3 cells form free floating spheres and are capable to multipotent differentiation.
