RESUMO
Intrastriatal, foetal neural transplants can ameliorate symptoms in patients with Parkinson's and Huntington's disease, although not stop the primary cell-loss. Several issues must, however, be addressed before general or extended clinical use of cell therapy in neurodegenerative diseases can become a reality. Improvements include standardized and safe master cell-lines derived from human embryonic stem cells, induced pluripotent stem cells and neural stem cells. Cells from these sources are expected to become available for cell replacement therapies or therapeutic production of trophic, anti-inflammatory and restorative factors within a few years.
Assuntos
Doenças Neurodegenerativas/terapia , Transplante de Células-Tronco , Animais , Reprogramação Celular , Células-Tronco Embrionárias/fisiologia , Células-Tronco Embrionárias/transplante , Transplante de Tecido Fetal , Humanos , Doença de Huntington/terapia , Doença de Parkinson/terapia , Células-Tronco Pluripotentes/fisiologia , Células-Tronco Pluripotentes/transplante , Transplante de Células-Tronco/métodosRESUMO
Generation of new nerve cells (neurogenesis) is normally considered to be limited to the fetal and early postnatal period. Thus, damaged nerve cells are not expected to be replaced by generation of new cells. The brain is, however, more plastic than previously assumed. This also includes neurogenesis in the adult human brain. In particular two brain regions show continuous division of neural stem and progenitor cells generating neurons and glial cells, namely the subgranular zone of the dentate gyrus and the subventricular zones of the lateral ventricles. From the latter region newly generated neuroblasts (immature nerve cells) migrate toward the olfactory bulb where they differentiate into neurons. In the dentate gyrus the newly generated neurons become functionally integrated in the granule cell layer, where they are believed to be of importance to learning and memory. It is at present not known whether neurogenesis in the adult human brain can be manipulated for specific repair after brain damage.