Cell implantation therapies for Parkinson's disease using neural stem, transgenic or xenogeneic donor cells

A new therapeutic neurological and neurosurgical methodology involves cell implantation into the living brain in order to replace intrinsic neuronal s ystems, that do not spontaneously regenerate after injury, such as the dopa minergic (DA) system affected in Parkinson's disease (PD) and aging. Curren t clinical data indicate proof of principle for this cell implantation ther apy for PD. Furthermore, the disease process does not appear to negatively affect the transplanted cells, although the patient's endogenous DA system degeneration continues. However, the optimal cells for replacement, such as highly specialized human fetal dopaminergic cells capable of repairing an entire degenerated nigrostriatal system, cannot be reliably obtained or gen erated in sufficient numbers for a standardized medically effective interve ntion. Xenogeneic and transgenic cell sources of analogous DA cells have sh own great utility in animal models and some promise in early pilot studies in PD patients. The cell implantation treatment discipline, using cell fate committed fetal allo- or xenogeneic dopamine neurons and glia, is currentl y complemented by research on potential stem cell derived DA neurons. Under standing the cell biological principles and developing methodology necessar y to generate functional DA progenitors is currently our focus for obtainin g DA cells in sufficient quantities for the unmet cell transplantation need for patients with PD and related disorders. (C) 2001 Elsevier Science Ltd. All rights reserved.