Tooth cells may help treat Parkinson's disease

Cells derived from the inside of a tooth might someday 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. The study's lead author is Christopher Nosrat, an assistant professor of biological and materials sciences at the University of Michigan School of Dentistry.

This is not the first test of stem cells as a therapy for Parkinson's disease-type illnesses, known as neurodegenerative diseases, but Nosrat noted 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 said. The cells produce a host of beneficial "neurotrophic" factors, which promote nerve cell survival.

Parkinson's disease is characterized by symptoms including tremors of the hands, arms or legs, rigidity of the body and difficulty balancing while 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. An estimated 1 million Americans suffer from Parkinson's disease, for which there is no cure.

Nosrat's study involved evaluating the potential of injecting tooth cells into brain cells as a possible cell-based therapy for Parkinson's. He was testing whether the tooth cells could provide neurotrophic factors to support dying nerve cells and replace dead cells.

Nosrat also has studied dental pulp stem cells as a treatment for spinal cord injuries and said 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 the center of the tooth, then culture them in a Petri dish to increase the number of the cells. The cell mixture then contains neuronal precursor cells and cells that produce beneficial neurotrophic factors.

Nosrat emphasized 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 is still 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, and in animal and human studies, most of those 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 method---by focusing the treatment much more specifically on affected parts of the brain and the co-delivery of neurotrophic factors---he can eventually achieve success.

European Journal of Neuroscience is the official journal for the federation of European neuroscience societies: https://onlinelibrary.wiley.com/ 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 co-authors are his wife, Irina Nosrat, Christopher Smith and Patrick Mullally, at the U-M 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.

Nosrat's faculty profile: https://dent.umich.edu/

A release on Nosrat's work in spinal cord injuries: http://www.umich.edu/~newsinfo/Releases/2001/Sep01/r090401.html