RESUMO
By optimizing the previously described strategy for obtention of spheres enriched in PSA-NCAM+ precursors, we prepared PSA-NCAM-immunoselected cell populations from cerebral hemispheres of neonatal MBP-LacZ transgenic mice. These cells expressed Nestin, exhibited clonal expansion potential and formed spheres, which were initially enriched in PSA-NCAM+ cells but became enriched in GD3+ oligodendrocyte progenitors after 1 week in B104 contionned medium. One month after their periventricular transplantation into the brain of wild-type and/or shiverer newborn mice, cells from PSA-NCAM+ spheres exhibited a higher rostral migration potential than cells from GD3+ spheres, and clearly contributed to myelination in the olfactory bulb. In shiverer hosts, both sphere populations generated oligodendrocytes with similar myelination potential. In addition PSA-NCAM+ sphere cells generated GFAP+ astrocytes and NeuN+ neurons, depending on their site of insertion. These results evidence the high plasticity of newborn PSA-NCAM+ neural precursors and suggest that they are promising tools for cell therapy of CNS diseases, including myelin disorders.
Assuntos
Encéfalo/crescimento & desenvolvimento , Diferenciação Celular/fisiologia , Linhagem da Célula/fisiologia , Movimento Celular/fisiologia , Proteínas do Tecido Nervoso , Molécula L1 de Adesão de Célula Nervosa , Moléculas de Adesão de Célula Nervosa/metabolismo , Neurônios/transplante , Ácidos Siálicos/metabolismo , Transplante de Células-Tronco , Animais , Antígenos de Diferenciação/metabolismo , Astrócitos/citologia , Astrócitos/metabolismo , Encéfalo/citologia , Encéfalo/metabolismo , Transplante de Tecido Encefálico/métodos , Agregação Celular/genética , Técnicas de Cultura de Células/métodos , Células Cultivadas/citologia , Células Cultivadas/efeitos dos fármacos , Células Cultivadas/metabolismo , Doenças do Sistema Nervoso Central/cirurgia , Células Clonais/citologia , Células Clonais/efeitos dos fármacos , Células Clonais/metabolismo , Meios de Cultura/farmacologia , Gangliosídeos/metabolismo , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Proteína Glial Fibrilar Ácida/metabolismo , Sobrevivência de Enxerto/fisiologia , Proteínas de Filamentos Intermediários/metabolismo , Camundongos , Camundongos Transgênicos , Nestina , Moléculas de Adesão de Célula Nervosa/genética , Neurônios/citologia , Neurônios/metabolismo , Oligodendroglia/citologia , Oligodendroglia/metabolismo , Ácidos Siálicos/genética , Células-Tronco/citologia , Células-Tronco/metabolismo , Tálamo/citologia , Tálamo/crescimento & desenvolvimento , Tálamo/cirurgiaRESUMO
Coupling of biotin to an endogenous lectin yields a probe which can be used for selective nonradioactive detection of complementary endogenous ligands. To exemplify practical applications of this type of compounds, we have synthesized and characterized a biotinylated derivative of a beta-galactoside-specific human brain lectin. Proteins which bind this lectin can be located on nitrocellulose sheets after electrophoretic transfer from gradient polyacrylamide gels, by sequential incubation with biotinylated probes and streptavidin-peroxidase, with visualization by an insoluble reaction product (affinoblotting). Biotinylated galactoside-binding plant lectins were used in the same way to visualize human brain glycoproteins, and their binding specificity was compared with that of human brain lectin. The results obtained by means of these different probes showed the usefulness of the endogenous lectin derivative to actually identify its endogenous partners. Thus this approach may find extended applications in the study of biological activities of vertebrate lectins in homologous systems, i.e., with lectins and ligands coming from the same tissue origin.