Cell Transplantation for Parkinson's Disease: Present Status

Abstract

1. Parkinson's disease (PD) is a neurodegenerative disorder caused by the loss of neurons in the substantia nigra pars compacta and a striatal deficiency of dopamine. PD typically affects people in late middle age and progresses slowly. In the early stages of the disease, treatment targeting the dopaminergic network is effective. However, with disease progression, transplantation is an option for repairing and replacing missing dopaminergic neurons. 2. In this review, we evaluate the tissue grafts and cellular therapies that have and are being considered. Clinical trials were originally derived from transplants of adrenal medullary chromaffin cells and embryonic nigral dopaminergic neurons in patients with PD. 3. Recently, novel molecular and cellular treatments are being utilized in animals and these include embryonic stem cells, fetal cells from pigs, or transfected cells. In spite of new molecular techniques and some 20 years of experience, the transplantation therapy for PD has today the same problems and results as the first reports which used neural fetal tissue or adrenal grafts.

Current status of experimental cell replacement approaches to spinal cord injury

“…30 Some recent reports have suggested that fetalderived NPCs can differentiate into neurons and oligodendrocytes after transplantation into a contusion SCI model with some improved behavioral outcome. 72,95 The transplantation of OECs from fetal sources, popularized by Huang and colleagues 28 in China, has gained considerable media attention; however, the limited scientific data from this study severely limit enthusiasm for this procedure as a therapeutic option in patients.…”

Photoreceptor differentiation and integration of retinal progenitor cells transplanted into transgenic rats

“…Despite pioneering work beginning in the 1960s (Davis and Temple, 1994;Gage et al, 1995;Johansson et al, 1999a,b;Reh and Levine, 1998;Snyder et al, 1997;Weiss et al, 1996) providing substantial evidence to the contrary, the existence of adult neurogenesis was not extensively accepted until recent fundamental advances in developmental biology in the 1990s (Davis et al, 1994;Gage et al, 1995;Johansson et al, 1999a,b;Reh and Levine, 1998;Snyder et al, 1997;Weiss et al, 1996). Indeed, the discovery of neural stem cells in the adult has raised the possibility for the development of potential powerful new therapeutic strategies to restore function in degenerative neurological diseases including Parkinson's disease (PD), Huntington's disease (HD), Alzheimer's disease (AD), retinitis pigmentosa (RP) and age-related macular degeneration (AMD) (Armstrong et al, 2003;Baetge, 1993;Bjorklund, 2000;Drucker-Colin and Verdugo-Diaz, 2004;Freeman et al, 2000;Martinez-Serrano and Bjorklund, 1997;Redmond, 2002;Sayles et al, 2004;Storch and Schwarz, 2002).…”

Is there a role for chromaffin progenitor cells in neurodegenerative diseases?

“…The beneficial effects, however, were transient and longterm survival and functional efficacy of these grafts were poor, and the clinical improvements disappeared after 1-2 years. 3 Transplantation of fetal dopaminergic neural progenitors from the midbrain of aborted embryos and fetuses is another promising strategy. Several clinical open-label trials with these transplants have proven successful in the treatment of Parkinson's patients where dopamine release was restored in the striatum and to significantly reverse some of the symptoms of the disorder.…”