MicroRNA lowers levels of protective protein in brain regions important for the development of alcohol addiction
A team of UC San Francisco researchers has found that a tiny segment of genetic material known as a microRNA plays a central role in the transition from moderate drinking to binge drinking and other alcohol use disorders.
Previous research in the UCSF laboratory of Dorit Ron, PhD, Endowed Chair of Cell Biology of Addiction in Neurology, has demonstrated that the level of a protein known as brain-derived neurotrophic factor, or BDNF, is increased in the brain when alcohol consumed in moderation. In turn, experiments in Ron's lab have shown, BDNF prevents the development of alcohol use disorders.
In the new study, Ron and first author Emmanuel Darcq, PhD, a former postdoctoral fellow now at McGill University in Canada, found that when mice consumed excessive amounts of alcohol for a prolonged period, there was a marked decrease in the amount of BDNF in the medial prefrontal cortex (mPFC), a brain region important for decision making. As reported in the October 21, 2014 online edition of Molecular Psychiatry, this decline was associated with a corresponding increase in the level of a microRNA called miR-30a-5p.
MicroRNAs lower the levels of proteins such as BDNF by binding to messenger RNA, the molecular middleman that carries instructions from genes to the protein-making machinery of the cell, and tagging it for destruction.
Ron and colleagues then showed that if they increased the levels of miR-30a-5p in the mPFC, BDNF was reduced, and the mice consumed large amounts of alcohol. When mice were treated with an inhibitor of miR-30a-5p, however, the level of BDNF in the mPFC was restored to normal and alcohol consumption was restored to normal, moderate levels.
"Our results suggest BDNF protects against the transition from moderate to uncontrolled drinking and alcohol use disorders," said Ron, senior author of the study and a professor in UCSF's Department of Neurology. "When there is a breakdown in this protective pathway, however, uncontrolled excessive drinking develops, and microRNAs are a possible mechanism in this breakdown. This mechanism may be one possible explanation as to why 10 percent of the population develop alcohol use disorders and this study may be helpful for the development of future medications to treat this devastating disease."
One reason many potential therapies for alcohol abuse have been unsuccessful is because they inhibit the brain's reward pathways, causing an overall decline in the experience of pleasure. But in the new study, these pathways continued to function in mice in which the actions of miR-30a-5p had been tamped down—the mice retained the preference for a sweetened solution over plain water that is seen in normal mice.
This result has significant implications for future treatments, Ron said. "In searching for potential therapies for alcohol abuse, it is important that we look for future medications that target drinking without affecting the reward system in general. One problem with current alcohol abuse medications is that patients tend to stop taking them because they interfere with the sense of pleasure."
Also participating in the study were postdoctoral fellows Vincent Warnault, PhD, and Feng Liu, PhD; former postdoctoral fellow Gabriel Mercado Besserer, PhD, and Khanhky Phamluong, research associate.
The study was supported by grants from the National Institute on Alcohol Abuse and Alcoholism and from the State of California for medical research on alcohol and substance abuse through UCSF.
UCSF is the nation's leading university exclusively focused on health. Now celebrating the 150th anniversary of its founding as a medical college, UCSF is dedicated to transforming health worldwide through advanced biomedical research, graduate-level education in the life sciences and health professions, and excellence in patient care. It includes top-ranked graduate schools of dentistry, medicine, nursing and pharmacy; a graduate division with world-renowned programs in the biological sciences, a preeminent biomedical research enterprise and two top-tier hospitals, UCSF Medical Center and UCSF Benioff Children's Hospital San Francisco. Please visit http://www.ucsf.edu.
Pete Farley | Eurek Alert!
Cryo-electron microscopy achieves unprecedented resolution using new computational methods
24.03.2017 | DOE/Lawrence Berkeley National Laboratory
How cheetahs stay fit and healthy
24.03.2017 | Forschungsverbund Berlin e.V.
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
24.03.2017 | Materials Sciences
24.03.2017 | Physics and Astronomy
24.03.2017 | Physics and Astronomy