RESUMEN
Stimulation of cell regeneration in the brain and eye retina in various degenerative processes is a pressing problem in neurobiology. A promising approach is transplantation of somatic cells reprogrammed towards neural lineage. We studied the effect of transplantation of retinal pigment epithelial cells from adult human eye transdifferentiated in culture on degenerative processes in the brain of rats subjected to acute hypoxia. Immunohistochemical and molecular genetic analysis suggests that retinal pigment epithelial cells transdifferentiate in vitro and express markers of low-differentiated neural cells. The cells transplanted into rat brain survive for at least 20 days. During this period, they stimulate compensatory and reparative processes that protected cortical neurons in the recipients from hypoxia-induced degeneration.
Asunto(s)
Transdiferenciación Celular , Reprogramación Celular , Células Epiteliales/citología , Hipoxia/terapia , Neuronas/trasplante , Adulto , Animales , Biomarcadores/metabolismo , Encéfalo/metabolismo , Encéfalo/patología , Células Cultivadas , Células Epiteliales/metabolismo , Expresión Génica , Humanos , Hipoxia/metabolismo , Hipoxia/patología , Proteínas del Tejido Nervioso/genética , Proteínas del Tejido Nervioso/metabolismo , Neuronas/citología , Neuronas/metabolismo , Ratas , Epitelio Pigmentado de la Retina/citología , Epitelio Pigmentado de la Retina/metabolismo , Trasplante Heterólogo , Resultado del TratamientoRESUMEN
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.
Asunto(s)
Neocórtex/metabolismo , Células-Madre Neurales/metabolismo , Retina/metabolismo , Células Cultivadas , Proteínas del Ojo/metabolismo , Proteínas de Homeodominio/metabolismo , Humanos , Proteína Homeótica Nanog , Factor 3 de Transcripción de Unión a Octámeros/metabolismo , Factor de Transcripción PAX6 , Factores de Transcripción Paired Box/metabolismo , Proteínas Represoras/metabolismo , Factores de Transcripción SOXB1/metabolismo , Proteínas Supresoras de Tumor/metabolismoRESUMEN
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.
Asunto(s)
Epitelio Pigmentado Ocular/metabolismo , Retina/metabolismo , Diferenciación Celular/genética , Diferenciación Celular/fisiología , Células Cultivadas , Proteínas del Ojo/genética , Proteínas del Ojo/metabolismo , Proteínas de Homeodominio/genética , Proteínas de Homeodominio/metabolismo , Humanos , Inmunohistoquímica , Proteína Homeótica Nanog , Factor 3 de Transcripción de Unión a Octámeros/genética , Factor 3 de Transcripción de Unión a Octámeros/metabolismo , Factor de Transcripción PAX6 , Factores de Transcripción Paired Box/genética , Factores de Transcripción Paired Box/metabolismo , Epitelio Pigmentado Ocular/citología , Reacción en Cadena de la Polimerasa , Proteínas Represoras/genética , Proteínas Represoras/metabolismo , Retina/citología , Proteínas Supresoras de Tumor/genética , Proteínas Supresoras de Tumor/metabolismo , cis-trans-Isomerasas/genética , cis-trans-Isomerasas/metabolismoRESUMEN
Neurotransplantation of various cells, including heterotransplantation of fetal cerebral stem/progenitor cells into the eye is used in experimental studies of central nervous tissue repair during neurodegeneration. For evaluation of this approach, human fetal (weeks 9-20) stem/progenitor cells of the neocortex and retina were studied in vivo and in vitro by quantitative PCR and immunohistochemical staining. Native tissues and cultures were characterized by expression of Pax6 transcription factor (critical for the development of the retina and neocortex) and differentiation markers (nestin, betaIII-tubulin, glial fibrillary acidic protein, recoverin, NeuN, neurofilaments, Ki-67). The expression of Pax6 gene in the retina during active neurogenesis was stable and much higher than in the neocortex. In primary cultures, the pattern of Pax6 gene expression is retained and repeats that in native tissues. Immunohistochemical analysis revealed similarity of nestin and betaIII-tubulin expression in the neocortex and retina during the early (9-10 weeks) and later (20 weeks) periods and differences in cell phenotypes and their distribution. Culture studies showed that neocortical and retinal stem/progenitor cells are determined and exhibit specific differentiation characteristic of the corresponding native tissues. It can be hypothesized that heterotransplantation of the cerebral progenitor cells into the retina of experimental animals can lead to realization of their neurotrophic effect, but not to their functional integration.