Stem cell therapy in amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a rare and lethal neurodegenerative disease for which there is no effective medical treatment. Although riluzole, an N-methyl-d-aspartate receptor antagonist, has been shown to be reasonably safe for patients with ALS, the drug has been demonstrated to prolong median survival by only 2-5 months. There is mounting evidence that stem cell-based gene therapy is a promising treatment modality for patients with ALS. In this review, we focus on the types, sources, and doses of stem cells that have been shown to be effective for ALS patients, the differences in cytokines or chemokines secreted from these various stem cells, and the immune-modulation activity of stem cells as treatment for ALS.