ABSTRACT
Stem cells and their powerful therapeutic potential have been studied since their discovery in the 19th century. Today, stem cells are being used to study and treat all manner of neurological diseases. Since their discovery, several distinct stem cell populations have been shown to harbor therapeutic potential: embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) are used to model a diversity of disease states, hematopoietic stem cells (HSCs) which form the precursors for all blood cells, neural stem cells (NSCs) which later develop into brain tissue, mesenchymal stem cells (MSCs) which can readily repopulate cells of mesodermal lineage. The potential of all these different stem cell lines is based on their ability to repopulate or regenerate damaged tissue environments that contribute to the complex pathophysiology of the underlying disease. In multiple sclerosis, HSC transplant has proven to be a successful therapy and has reached Phase III clinical trials. Similar strategies are being employed in stroke, to re-establish vascularization in infarcted areas. MSCs have also seen success through inhibition of the inflammatory environment post-stroke and have progressed through to Phase III clinical trials. Researchers studying spinal cord injury and cerebral palsy have also observed positive results with MSC inhibition of inflammation. Projects utilizing NSCs to treat amyotrophic lateral sclerosis, Parkinson's disease, and Alzheimer's disease in animal models hold promise for the eventual success of these treatment modalities. In this review, we will examine the current trends in the utilization of stem cells to treat and research neurological diseases.
