Epigenetic predictors of lifestyle traits in blood and the brain
A recent publication in the journal Brain Communications from Riccardo Marioni’s group compares DNA methylation patterns seen in blood as predictors of lifestyle traits with epigenetic changes in brain tissue. May 21
A range of modifiable lifestyle factors have been linked to genome-wide DNA methylation pattern changes in the blood. In addition these factors - smoking, alcohol consumption and body mass index, can influence the risk of developing neurological disease. While the epigenetic changes seen in blood samples are likely a consequence of these lifestyle factors, the authors of this paper looked to see whether similar changes were also seen in tissues of the brain.
The research team used data from a unique and rarely-available set of DNA methylation samples from five post-mortem regions of the brain, in comparison with the last blood sample taken prior to death, in 14 individuals from the Lothian Birth Cohort 1936. By applying DNA methylation signatures of lifestyle traits from the blood to these data from brain tissue they tested whether the blood and brain signatures of lifestyle traits were similar within the same individuals.
Results from the study showed that correlations between blood and brain scores for the four lifestyle traits investigated - smoking, high-density lipoprotein cholesterol, alcohol and body mass index, were highly variable across brain regions, suggesting that blood measures of methylation often poorly relate to what is happening in the brain.
One region however, the dorsolateral prefrontal cortex, had the strongest similarities between blood and brain signatures of smoking. This region could therefore be particularly vulnerable to smoking-related changes in methylation, which may affect the risk a person has of developing neurological disease.
This work, though preliminary in nature, gives us an insight into the way that lifestyle factors may affect methylation patterns in the brain. This is important to understand, given that modifiable lifestyle factors are linked to the onset of various neurological diseases. We would like to thank all participants who have contributed to the Lothian Birth Cohort datasets available to researchers. Without them, this unique dataset would not be available.
Paper in Brain Communications https://doi.org/10.1093/braincomms/fcab082
Marioni Group website