A new study on the aging clock was published by the University of Lausanne in Switzerland.
The research proposes a novel method for constructing an EpiNutriGenetics™ aging clock based on chromatin accessibility and confirms that this approach is directly linked to age-related changes in the transcriptome state.
Moreover, it demonstrates that this method can predict age more accurately compared to traditional transcriptome aging clocks.
In this work, researchers collected blood samples from 159 human donors and generated a series data including chromatin accessibility, transcriptome, and cellular composition. By analyzing combined epi-data, the group achieve the final constructed aging clock with a median absolute error of less than 5.27 years.
This new clock is based on ATAC-Seq (Assay for Transposase Accessible Chromatin with high-throughput sequencing), a high-throughput sequencing technology that utilizes transposase to study chromatin accessibility.
The concept of the earliest reliable transcriptome clock was introduced in 2015 by Peters et al., who improved upon previous classification methods to enable age prediction calculations. They developed a transcriptional aging clock based on whole-blood microarray samples from human genome, reporting a correlation coefficient as high as 0.6 and an average difference of 7.8 years.
In this study, researchers repeatedly tested the ATAC-Seq and RNA-Seq data collected from 159 samples.
They discovered that the aging clock constructed based on chromatin accessibility had a Pearson correlation coefficient up to 0.86, higher than the Pearson correlation coefficient of 0.78 for the aging clock constructed by only gene transcriptome data.
The novelty of this aging clock lies in its approach with consideration of the distribution of chromatin states rather than focusing on changes in DNA methylation or gene transcription levels during the aging process, as previous studies have done.
However, due to the lack of sufficient ATAC-seq data with reported age information, the age prediction of this clock is still subject to certain limitations. In the future, the performance and accuracy of this clock need to be further improved by collecting more reliable samples to the training set.
