Epigenetic age and the environment: Is Age Acceleration a Thing?

DNA methylation is the most easily measured epigenetic mark. It is an ancient mechanism of supressing transposable and viral DNA, recruited in evolution for diverse gene regulation jobs.

The mammalian genome is fully 5- methylated on the vast majority of C bases in CG dinucleotides. Profiling human samples, the most obvious variable is tissue type, reflecting the role of DNAm and other epigenetic marks in laying down the developmental programme.

For nearly every human sample profiled, the subject's age is available. It was noticed early that there are numerous CG loci where the methylation status associates with subject age. The mechanism or mechanisms of this remain unknown, but a large literature has developed on epigenetic clocks, and discrepancies between estimated and chronological age (age acceleration) as a possible index of environmental effects. There has even been a report of a drug treatment reducing epigenetic age, interpreted as increasing predicted lifespan.

Looking at data sets from our Alzheimer Disease study and the UK Household Longitudinal survey, Professor Schalkwyk looks at what the clock really is.

Speaker

Professor Leo Schalkwyk is Professor of Human Genetics in the School of Life Sciences.