Cell replacement strategies for neurodegenerative disorders.
Cell transplantation has over the last two decades emerged as a promising approach for restoration of function in neurodegenerative diseases, in particular Parkinson's and Huntington's disease. Clinical trials have so far focused on the use of implants of embryonic mesencephalic tissue containing already fate-committed dopaminergic neuroblasts with the capacity to develop into fully mature dopamine neurons in their new location in the host brain. However, the recent demonstration that immature neural progenitor cells with multipotent properties can be isolated from both the developing and adult CNS and that these cells can be maintained and propagated in culture, has provided a new interesting tool for restorative cell replacement and gene transfer therapies. Embryonic stem cells, obtained from the early stages of embryonic development, and neural stem cells, obtained from the developing brain, may provide renewable sources of cells for therapeutic purposes, and could eventually offer a powerful alternative to primary fetal CNS tissue in clinical transplantation protocols. The purpose of this review is to discuss the prospects of the emerging progenitor cell technology for cell replacement and restorative therapies in neurodegenerative diseases, and consider some of the critical issues that must be solved in order to make progenitor cells useful in studies of brain repair.
Björklund
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Wallenberg Neuroscience Center, Department of Physiological Sciences, Lund University, Sölvegatan 17, S-223 62 Lund, Sweden.
D000818:Animals; D016380:Brain Tissue Transplantation / Q000379:methods* / Q000639:trends; D016332:Fetal Tissue Transplantation / Q000379:methods* / Q000639:trends; D006801:Humans; D006816:Huntington Disease / Q000601:surgery*; D009474:Neurons / Q000637:transplantation*; D010300:Parkinson Disease / Q000601:surgery*