Cell Therapy Strategies vs. Paracrine Effect in Huntington's Disease.

Huntington's disease (HD) is a genetic neurodegenerative disorder. The most common symptom of HD is abnormal involuntary writhing movements, called chorea. Antipsychotics and tetrabenazine are used to alleviate the signs and symptoms of HD. Stem cells have been investigated for use in neurodegenerative disorders to develop cell therapy strategies. Recent evidence indicates that the beneficial effects of stem cell therapies are actually mediated by secretory molecules, as well as cell replacement. Although stem cell studies show that cell transplantation provides cellular improvement around lesions in in vivo models, further work is required to elucidate some issues before the clinical application of stem cells. These issues include the precise mechanism of action, delivery method, toxicity and safety. With a focus on HD, this review summarizes cell therapy strategies and the paracrine effect of stem cells.