Stem cell transplantation for neurometabolic and neurodegenerative diseases

Over the last decade, the potential for therapeutic use of stem cell transplantation for cell replacement or as cellular vectors for gene delivery for neurometabolic and neurodegenerative diseases has received a great deal of interest. There has been substantial progress in our understanding of stem cell biology. Potential applications of cell-mediated therapy include direct cell replacement or protection and repair of the host nervous system. Given the complexities of the cellular organization of the nervous system, especially in diseased states, it seems that using stem cells as cellular vectors to prevent or ameliorate neurological disorders rather than cell replacement and the regrowth of damaged circuitry is more likely to succeed in the near term. Recent success in the treatment of lysosomal storage diseases with genetically modified stem cells support this notion. In Alzheimer's and Parkinson's diseases, stem cell therapy is at its early stages and data generated in animal models and clinical trials using other cell types suggest that a combination of gene and stem cell therapy may be an optimal therapeutic paradigm.