In a new study, researchers located a single gene that can improve the body's response to drug addiction and depression. The team's findings were published in the journal Nature Neuroscience.
Epigenetics is the study of changes in the action of genetics caused by molecules that determine how genes are activated.
The team studied mice for depression, stress, and addiction in relation to the gene FosB, which scientists previously linked to depression and drug addiction in humans. The gene FosB is located in a brain reward region. The researchers used synthetic-transcription factors to alter the activity of that gene in mice. By altering that gene alone, the researchers found that the mice became less likely to succumb to depression and less likely to become addicted to cocaine.
The researchers did not change the DNA of the mice. They simply altered the way the mice's DNA was expressed by changing the transcription process. Although all of our DNA is present all of the time, many of the genes remain inactive most of the time. The scientists were able to change the expression of the FosB gene by introducing a new molecule called Zinc Finger Proteins (ZFPs), a synthetic transcription factor. The ZFP was introduced to the mice by way of a genetically-modified virus. After the virus entered the mice, the FosB-ZFPs could either repress expression of the FosB gene or activate expression of the gene.
"Earlier work in our laboratory found that several transcription factors and downstream epigenetic modifications are altered by exposure to drugs or to stress and that these changes, in turn, control gene expression. But because such epigenetic regulation occurs at hundreds or thousands of genes, until now it had been impossible to determine the difference between the mere presence of an epigenetic modification and its functional relevance to neuropsychiatric disease," said Eric J. Nestler, MD, PhD, who led the study.
Synthetic-transcription factors might hold the key to a new way to treat depression and drug addiction, as well as other diseases like cancer. Dr. Elizabeth Heller, one of the researchers on this study, hopes to use these techniques to find the cure to neuropsychiatric diseases.