Dental pulp cells may hold key to treatment of Parkinson's disease
Cells derived from the inside of a tooth someday might prove an effective way to treat the brains of people suffering from Parkinson's disease.
A study in the May 1 issue of the European Journal of Neuroscience shows dental pulp cells provide great support for nerve cells lost in Parkinson's disease and could be transplanted directly into the affected parts of the brain, says lead author Christopher Nosrat. Nosrat is assistant professor of biological and materials sciences at the School of Dentistry.
The study is not the first to test stem cells as a therapy for Parkinson's Disease-type illnesses, known as neurodegenerative diseases, but Nosrat notes that it is the first to use post-natal stem cells grown from more readily available tooth pulp in the nervous system.
Using dental pulp has other advantages besides its availability, Nosrat says. The cells produce a host of beneficial neurotrophic factorsglial cell-lined neurotrophic factor, nerve growth factor and brain-derived neurotrophic factorthat have the potential to promote the survival of brain neurons lost in Parkinson's disease.
An estimated 1 million Americans suffer from the disease, for which there is no cure. It is characterized by tremors of the hands, arms or legs, rigidity of the body, and difficulty balancing for such activities as standing or walking.
Parkinson's affects nerve cells in the part of the brain called the basal ganglia, which is responsible for control of voluntary movement.
Nosrat's study involved evaluating the potential of tooth cells for the development of a cell-based therapy for Parkinson's disease, and injecting tooth cells into that specific part of the brain, with the tooth cells providing neurotrophic support for dying nerve cells and replacing dead cells. Neurotrophic factors play a key role in the functioning of the nervous system.
Nosrat has studied dental pulp stem cells as a treatment for spinal cord injuries and says applying that knowledge to treatment of neurodegenerative disease was the next logical step.
He used the same general approach for this Parkinson's study: Researchers extract a tooth and draw cells from its center, then culture them in a Petri dish to increase the number of the cells. The mixture then contains neuronal precursor cells and cells that produce beneficial neurotrophic factors.
Nosrat emphasizes that there is much work to be done before human patients might find relief from Parkinson's symptoms as a result of this therapy. It still is many years from being tested in people as a possible treatment or cure for neurological disorders.
Previous studies have used other sources for stem cells. In animal and human studies, most of the cells die when grafted into the brain. Nosrat believes cells drawn from dental pulp are more robust because they also produce the neurotrophic factors, which promote nerve cell survival.
Nosrat hopes that by refining the delivery methodby focusing the treatment much more specifically on affected parts of the brain and the co-delivery of neurotrophic factorshe eventually can achieve success.
European Journal of Neuroscience is the official journal for the federation of European neuroscience societies; it is available at http://www.blackwellpublishing.com/journal.asp?ref=0953-816X&site=1. The article is titled "Dental pulp cells provide neurotrophic support for dopaminergic neurons and differentiate into neurons in vitro, implications for tissue engineering and repair in the nervous system."
Nosrat's coauthors are Irina Nosrat, Christopher Smith and Patrick Mullally at the School of Dentistry, and Lars Olson at the Karolinksa Institutet in Stockholm, Sweden.
Partial funding for the study came from the National Institute of Dental and Craniofacial Research, part of the National Institutes of Health, as well as from the Michigan Parkinson's Foundation.