Institute of Experimental Medicine CAS

Published 06. 08. 2021

In the current issue of the International Journal of Molecular Sciences (IF 5,923), a new study by a team of co-authors from the Dept. of Genetic Toxicology and Epigenetics and the Dept. of Nanotoxicology and Molecular Epidemiology IEM CAS has been published. The study is focused on the impact of nanoparticle exposure on DNA methylation. Apart from identifying differences in DNA methylation between the exposed and control groups, they focused on mapping methylation changes over time at the individual level. A total of 14 subjects were followed for four years, whereby the results showed fluctuation in methylation settings in both exposed and control persons. Overall, the changes were more pronounced in the exposed subjects, although for several CpG sites, no modification was noted when compared with the controls. These sites are linked with adaptation to the specific long-term exposure factor, and the process of epigenetic memory fixes them.

The previous research has mainly focused on the impact of environmental air pollution on subjects from various localities of the Czech Republic, differing in the level and type of pollution. The results indicated that one of the assumptions of genetic toxicology (an increased level of a stressor increases levels of markers of exposure, i.e. measurable changes in the organism) might not be universally valid, as the human organism can adapt to environmental conditions. The research resulted in the formulation of a model of epigenetic adaptation to exposure factors of the environment. The model shows the impact of chronic environmental exposure on DNA methylation settings, which fundamentally affects the function of genes (switching between cytosine and 5-methylcytosine in CpG sites may contribute to switching the genes on and off). As a result, the activity of the same genes in persons from different localities may significantly differ. The optimal methylation pattern for the given environment is set during prenatal development. However, as the process is flexible, the settings can be changed (adapted) during life. The unique mechanism is linked with the epigenetic memory allowing the persons who had lived in the polluted environment in the past and returned to this environment at a later time point to adapt to these conditions more easily. 

Future research will focus not only on methylation changes to various exposure factors but also on associations between adaptation and possible health impacts in the future. 

Link to the published publication:  https://www.mdpi.com/1422-0067/22/15/7834