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, βIII-tubulin, glial fi brillary acidic protein, recoverin, NeuN, neurofi laments, 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 βIII-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 specifi c 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.
human neural stem/progenitor cells retina neocortex Pax6immunohistochemistry cell cultures