Ancient viruses hidden in genes can play an important role in addiction

An unusual version of retrovirus (a virus with genetic material that is RNA molecule) between genes involved in brain chemistry is found more in addicts than the rest of the population. number.

Currently, researchers have evidence that this pathogen may be responsible for neurological changes, risking the development of addiction and predicting it is likely to become a harmful retrovirus. since Tuesday was discovered.

In a recent study led by researchers from Oxford University and the University of Athens, scientists showed how the genetic material of a virus works without affecting nearby genes. . They found that one of the causes is related to dopaminergic activity .

Our genome is a virtual cemetery of ancient microorganisms, reverse coding allows retroviruses to copy its own RNA into our DNA and often these new genetic material will not disappear. through generations.

Some types of viruses.

"Most people think these ancient viruses are harmless," said University of Athens epidemiologist Gkikas Magiorkinis. It's true. Most of this genetic material seems to be harmless. They can account for 8% of our encoded genes in one form or another. Endogenous retrovirus in human K type (HML-2) - referred to as HK2 - is an example. We all carry its genes for about a million years.

Unlike many other retroviruses that lurk in our genetic code, HK2 may not be a deadly genetic code. Its genetic code is still potentially functional and capable of creating viruses that help it infect. This does not indicate that it is 'alive' or that it is even dangerous. But this new discovery can change the way we look at it.

There exists everywhere like HK2, there are many different variants hidden in our entire population. One of the special things that has been found is that about 5 to 10 percent of the population has two gene sequences responsible for a protein called RASGRF2 .

The role of this protein is associated with the release of neurotransmitters, especially dopamine - an important messenger in the self-rewarding process of the brain. But there is another version of RASGRF2 that has been linked to alcoholism in adolescence and this gene has also been studied in the management of alcohol-induced signaling in the rat brain. Therefore, there is a retrovirus that still has a function within the gene that makes people an attractive candidate to test possible effects on addictions.

Researchers have explored the database containing the genetic information of people with hepatitis C in the UK as well as a similar Greek database of people infected with HIV to determine the spectrum variable of RASGRF2 version of HK2. The results show that there are significant differences between those who have experienced drug use and those who do not. Of the 184 individuals in the British sample, the likelihood of finding invasive viruses was 3.6 times higher among chronic drug users. Similarly, the opportunity to find HK2 inside the RASGRF2 of chronic drug users is twice as high as those not used in the Greek HIV database.

To see if the intrusion code could affect gene expression, they used to convert the HK2 gene sequence into a typical RASGRF2 gene in a cultured cell.

While the experiment could not go so far as to demonstrate complex changes in animal behavior, they showed that inserting a fake virus into the 'normal' RASGRF2 gene had a profound effect on how it was interpreted and convert into a protein.

Of course, addiction is much more complicated than a simple genetic change. Not all individuals in the study of chronic substance abuse have HK2 hidden inside the gene and not all people who contain the virus's genes are addicted. But duplication indicates that the virus may be a factor that makes a person less likely to use drugs to become addicted.

There are currently only two retroviruses considered to be fatal to humans: HIV and T-Lymphotropic . So when the debate about HK2 appears, this issue also raises interesting questions about the danger level of our "harmless" hidden retroviruses.

Magiorkinis said: 'In 2012, after 20 years of arguing about their pathogenic role in humans, we sought to test the high-risk hypothesis that endogenous retroviruses could be responsible for human disease. . For the first time, we were able to distinguish between causes and effects in pathogenicity of endogenous retrovirus ".

This study is published in PNAS.