05. 04. 2023
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The prestigious journal Environmental Pollution (IF 9,988) has published a new study by Andrea Rössnerová entitled “Effects of various environments on epigenetic settings and chromosomal damage“, in which the scientific teams from the Department of Nanotoxicology and Molecular Epidemiology and the Department of Genetic Toxicology and Epigenetics participated. This study aimed to analyse in detail the integrity and function of the genome in a population of people from the Moravian-Silesian Region, who had been exposed to high levels of air pollution for a long time. The study builds on previous research and seeks an explanation for previously obtained unexpected results.
Humans are exposed to a large number of chemicals daily that can negatively affect their DNA and, thus, their health. Damage to the genetic material in human cells can be monitored using a number of genotoxicity tests, including the so-called micronucleus assay. This method can be used to determine the overall level of DNA damage caused by exposure to harmful substances such as polycyclic aromatic hydrocarbons, including the carcinogen benzo[a]pyrene. Unexpectedly but repeatedly, a low frequency of genetic damage has been observed over the last few years in people living in the Moravian-Silesian region, an area with chronic exposure to high concentrations of air pollutants, compared to residents of significantly less exposed locations.
For more than ten years, results from molecular biological analyses have been collected to find an explanation for these observations. Preliminary findings suggested an adaptation of the population from the Moravian-Silesian region. In the new study, the researchers used previous findings to examine the frequency of micronuclei by type for the first time, thus separating chromosomal breaks and losses. The latest results showed a significantly lower frequency of breaks in people from the Moravian-Silesian region. As previous results suggested differences between populations in the expression of the XRCC5 gene, whose protein plays an essential role in DNA break repair, possible differences in the epigenetic setting of this gene were also investigated. The observed hypomethylation of the XRCC5 gene and the concomitant possibility of increased DNA repair resulting in low break frequencies pointed to a specific mechanism of positive epigenetic adaptation with a protective effect for the population’s genome with a higher exposure burden.
These results are good news for our population. However, it is generally assumed that there are other mechanisms of genome adaptation to human environmental conditions, including genetic mechanisms, which should also be a direction for further research.
The full study can be found on the ScienceDirect website (open in a new window).