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Harmful cigarette consumption: How smoking affects our genes


Influence on genes: What exactly smoking does in our body

Smoking has been known to harm the lungs for a long time. But tobacco use has far more harmful effects, including on our genes. German researchers have now gained new insights into what exactly the blue haze does in our body.

Cigarette consumption harms health

The fact that tobacco harms health is nothing new. Smokers fall ill and not only die of lung cancer. Smoking cigarettes also increases the risk of several other types of cancer and other diseases such as smoker's lung or smoker's cough, asthma, chronic bronchitis, heart attack and stroke. In addition, cigarette consumption has a negative impact on our genes, as German researchers are now reporting.

Molecular details about the consequences of smoking

It has long been known that smoking is harmful, but only gradually does it become clear what exactly the blue haze does in our body.

Scientists from the German Center for Cardiovascular Research (DZHK) at the University Medical Center Hamburg-Eppendorf (UKE) have now uncovered new molecular details about the consequences of tobacco use.

According to a DZHK statement, the gene for a receptor that is involved in inflammation and the formation of new blood vessels is read more frequently in smokers than in non-smokers.

It also depends on how much you smoke

For the study, DZHK scientist Tina Haase, a doctoral student in the working group of Professor Tanja Zeller, both from the clinic and polyclinic for general and interventional cardiology at the University Heart Center Hamburg of the UKE, evaluated the data from a total of 1,292 subjects in a large population-based study .

According to the information, 593 of them were non-smokers, 477 former smokers and 221 smokers. According to the experts, the gene for the G protein-coupled receptor 15 (GPR15) was significantly more active in smokers than in non-smokers.

The gene activity was strongly associated with the number of cigarettes smoked per year: the more someone smoked, the more the gene for GPR15 was read.

The results of the study were published in the journal "Biomolecules".

Process can be reversed again

The good news is that this process can be reversed again. Those who had given up smoking also showed reduced activity of the GPR15 gene after some time.

However, the activity of the gene remained high in the study participants who continued to smoke unabated.

The researchers examined these long-term effects of smoking using the data collected at the start of the study and after five years.

The evaluated data of ex-smokers also showed that the decrease in GPR15 activity has been associated with the years since cigarette cessation and fell the most in the first few years.

GPR15 is involved in both new blood vessel formation and inflammatory processes. His exact role in these processes is not yet understood.

“Smoking is one of the main risk factors for cardiovascular diseases. Some of the diseases are caused by inflammatory processes. It is therefore very interesting to study the regulation and function of GPR15 in the cardiovascular system, ”says Haase.

Smoking leaves traces on the genetic material

At the beginning of the investigation, it was already known that a chemical change in a specific region in the GPR15 gene is linked to smoking.

This involves methylation, i.e. the attachment of a small methyl group to certain building blocks of the genetic material.

These small changes can affect how heavily packaged and thus how active certain sections of DNA are.

The research team was interested in the entire GPR15 gene and was able to identify three new regions that are more methylated in non-smokers than in smokers.

When you stop smoking, the methylation in these regions increases steadily, in parallel with the decreasing activity of the GPR15 gene.

"It is therefore quite possible that smoking will lower the methylation of the GPR15 gene, which will make the gene more readable," says Haase.

Assess smoking behavior exactly

Occasional smoker, pure party smoker, stress chain smoker - how much someone smokes is not so easy to measure. Questionnaires are currently being used for this.

Haase sees a possible application of her results here: Since GPR15 is regulated depending on the amount of cigarettes smoked, the GPR15 gene activity could be used as a biomarker in order to record smoking behavior more precisely in the future.

In principle, G protein-coupled receptors can be influenced very well by medication.

“That is why GPR15 is an exciting target, especially for the therapy of cardiovascular diseases. But that is still a long way off, ”says the young scientist. (ad)

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