WORCESTER, Mass.In recent years, a class of small molecules known as microRNA have been found to play an important role in regulating gene products in most animal and plant species. A new study now indicates that microRNA may influence the development of alcohol tolerance, a hallmark of alcohol abuse and dependence. Researchers supported by the National Institute on Alcohol Abuse and Alcoholism (NIAAA) report the findings in the July 31 issue of the journal Neuron.
"This is an intriguing contribution to efforts aimed at identifying the molecular bases of alcohol tolerance," noted NIAAA Director Ting-Kai Li, MD.
Tolerance is the decrease in sensitivity to alcohol that develops with repeated exposures to alcohol over time. Individuals who develop high tolerance (low sensitivity) to alcohol are at increased risk for becoming alcohol dependent. Thus, an important research objective has been to identify the adaptations within individual molecules that underlie tolerance.
In previous experiments, Steven N. Treistman, PhD, Professor of Psychiatry at the University of Massachusetts Medical School (UMMS), and colleagues at the university's Brudnick Neurospychiatric Research Institute (BNRI), determined that a brain cell membrane structure known as the BK channel develops tolerance to alcohol, particularly in the supraoptic nucleus and the striatum, two brain regions important in alcohol's effects. In both regions, alcohol tolerance was manifested as decreased alcohol sensitivity and reduced BK channel density. Previous studies have also shown that there are numerous variants of the BK channel gene.
In the current study, researchers led by Dr. Treistman, who is the director of the BNRI, examined whether microRNA might be involved in the alcohol tolerance observed in the BK channel.
In test tube experiments, the researchers showed that the amount of a specific microRNA molecule known as miR-9 increases in brain cells w
|Contact: Alison Duffy|
University of Massachusetts Medical School