Parkinson’s disease and stem cells

Abstract

Parkinson’s disease (PD) is a progressive neurodegenerative disorder affecting ˜1% of people over the age of 65. Prominent loss of the nigrostriatal dopaminergic neurons and deprivation of the striatal dopamine represents typical clinical symptom of motor abnormalities. Several treatment strategies have been developed for PD; including oral administration of dopamine precursor levodopa and/or dopamine agonists, and viral vectormediated gene therapy to deliver dopamine-synthesizing enzymes and neurotrophic factors to protect and potentially regenerate dopaminergic axon terminals. Of note, recent progress in stem cell biology provided excellent tools for replacement therapy targeting PD. Transplantation of stem cells and enhancement of intrinsic neurogenesis may provide a new source to recover the compromised neuronal functions in neurodegenerative conditions. On the other hand, one of the key pathogenic molecules in PD, a -synuclein, was recently found to affect neural stem cells. In this review, we will focus on the utility of stem cell therapy and a role of a -synuclein in adult neurogenesis in the brains affected with PD.