A study by the University of California of San Francisco has identified that problem drinking and alcoho abuse is regulated by microRNA. MicroRNAs (miRNAs) are small non-protein coding genes present in virtually all animals and plants. and tend to be transcribed from several different loci in the genome.
Previous research by the USF researchers has demonstrated that the level of a protein called brain-derived neurotrophic factor, or BDNF, is increased in the brain when alcohol consumed in moderation. BDNF acts a preventative mechanism for the development of alcohol use disorders.
In the current research study the researchers determined that 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 associated with decision making. The reduction of BDNF is correlated 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.
“Our results suggest BDNF protects against the transition from moderate to uncontrolled drinking and alcohol use disorders,” said Dorit 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.”
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.”