More than 100 million people worldwide are dependent on alcohol. To date, there is little that can be done medicinally to combat the disease. In addition, the recurrence rate is extremely high at up to 90 percent.
Now save articles for later in “Pocket”.
Researchers led by Subhash Pandey from the University of Illinois in Chicago have now discovered a molecular mechanism in rats that could pave the way for more efficient therapy for alcoholism, as they report in “Science Advances”.
Excessive drinking (binge drinking) in youth is one of the risk factors for alcohol dependence in adulthood, but also for anxiety disorders. During puberty, the brain is undergoing restructuring and is very sensitive to environmental influences.
The so-called arc gene is of particular importance: Not only does it play a central role in synaptic plasticity, it is also epigenetically modified under the influence of early alcohol consumption. Epigenetic modifications are reversible chemical changes in the DNA or histones that package the genome.
Depending on whether the DNA is compressed or loosened as a result, certain genes can be read better or worse or translated into proteins.
Young rats that were given a lot of alcohol to drink had less of the Arc protein in the amygdala, a region involved in both alcohol addiction and the regulation of anxiety, according to previous research by the group. Pandey and his colleagues found the same thing in brain sections of deceased alcoholic people.
In the current study, the team wanted to find out whether these changes can be reversed – the epigenetic switch can be flipped, so to speak. To do this, it used the CRISPR-Cas gene scissors, which can be used to change the histone packaging of the DNA in both directions.
In one of their experiments, the researchers repeatedly administered large amounts of alcohol to young rats between the ages of 27 and 41 (equivalent to 10 to 18 years of age in humans). They later used gene scissors on the adult, now alcoholic, animals in such a way that Arc production was boosted again. They then tested how often the rats drank water instead of alcohol and how anxious they were.
They compared both with the behavior of a non-alcoholic control group. The team found that CRISPR-Cas treatment increased levels of the Arc protein to normal levels in the alcoholic rats. In addition, the animals were now less anxious and also less dependent.
However, when Pandey and his colleagues injected control animals with a CRISPR-Cas system that suppressed Arc production, the rodents became anxious and drank alcohol. How exactly the protein arc influences alcohol consumption is still unclear. The scientists also point out that a lot still has to be done before the method is ready for use in humans.
The original of this article “Alcoholism: With the help of this protein, the cycle of addiction could be ended” comes from Spektrum.de.
