Promises and challenges of MSC-based therapies: Parkinson disease and parkinsonism

Parkinson disease (PD) and parkinsonism manifest as a group of neurological movement disorders resulting in uncoordinated and slowed movement, muscle rigidity, and often tremor and postural instability. In PD and the other neurodegenerative forms of parkinsonism, disease progression may lead to severe disability. However, present treatment focuses predominantly on symptom management as opposed to restoration of neuronal function. There is, therefore, intense interest in the potential for cell-based interventions. Beyond replacing damaged neurons, mesenchymal stem cells (MSCs) could provide benefit by virtue of their neurotrophic, antiinflammatory, antiapoptotic, and further effects. Encouraging preclinical studies of MSC function are now being translated into clinical trials in PD itself, as well as the more rapidly progressive Parkinson-plus syndromes, such as multiple system atrophy. In this chapter, we discuss the supporting evidence for this investigative approach, future prospects, and potential pitfalls of MSC-based treatment of PD and parkinsonism.