Lithium has been used to treat mood affective disorders, including bipolar disease for decades, according to background information in an article published online in the Journal of Biological Chemistry.
While the drug has been shown to protect neurons, the underlying mechanism of its therapeutic action is not understood. Moreover, lithium's therapeutic range is very limited in humans, and the drug has serious side effects.
Dr. Gordon J. Lithgow, a faculty member at the Buck Institute, says that their study provides a novel genetic approach to understanding how lithium works.
He says that the study also highlights the utility of using the nematode C. elegans as a research subject in the field of "pharmacogenetics", which involves the study of genetic factors that influence an organism's reaction to a drug.
The researchers have found that longevity was increased in the worms when the lithium "turned down" the activity of a gene that modulates the basic structure of chromosomes.
Dr. Lithgow believes that lithium impacts many genes.
"Understanding the genetic impact of lithium may allow us to engineer a therapy that has the same lifespan extending benefits. One of the larger questions is whether the lifespan extending benefits of the drug are directly related to the fact that lithium protects neurons," he said.
While the process of normal ageing is intrinsically linked to the onset of neurodegenerative disease in humans, the cellular changes and events that impact neurodegeneration have yet to be understood.
Dr. Lithgow stressed that studies involving compounds such as lithium could provide breakthroughs in the attempt to understand the biomedical link between aging and disease.
He and his colleagues are now surveying tens of thousands of compounds for affects on ageing.
"The use of simple model organisms with well developed genetic tools can speed the identification of molecular targets. This could facilitate the development of improved therapies for diseases," said Dr. Lithgow.