Stem Cell Therapy for Neurodegenerative Diseases: Strategies for Regeneration against Degeneration

Neurodegeneration is a general term for the progressive loss of structure and/ or function of neurons, gives rise to dysfunction or death of neurons. Neurodegenerative diseases including Alzheimers disease (AD), Parkinson's disease (PD), Huntington's disease (HD), amyotrophic lateral sclerosis (ALS), multiple sclerosis (MS), spinal cord injury (SCI) and brain ischemia (BI) occur as a result of neurodegenerative processes leading to different degrees of paralysis and loss of sensation and cognition in the patients. Unfortunately, no successful cure for neurodegenerative disorders has been developed so far, and most of the currently available pharmacological therapies are mainly palliative. In recent years, stem cells have provided a great opportunity to develop potentially powerful innovative strategies to cure neurodegenerative diseases. Stem cells transplantation is capable of restoring injured neuronal tissue by replacement of the damaged cells via using directly differentiated cells or by protecting of existing healthy neurons and glial cells from further damage, or by repairing through providing a conductive environment in favour of regeneration. Here we have brought together some of these examples, discuss possible therapeutic means using different types of stem cells, mainly adult stem cells (ASCs), to treat neurodegenerative diseases.