SRA

The establishment of highly accurate aging clocks based on DNA methylation highlighted the strong link between epigenetic alterations and aging. However, connecting methylation clocks to physiological changes is not straightforward. Transcriptomics and proteomics clocks on the other hand are directly connected to cellular function, yet they do not allow us to understand underlying epigenetic mechanisms. We hypothesize that chromatin accessibility, a readout that integrates many epigenetic mechanisms, may bridge epigenetic changes with their downstream effects in aging. To demonstrate that chromatin accessibility can predict age, we generated chromatin accessibility profiles from peripheral blood mononuclear cells (PBMCs) of 157 human donors, aged 20 to 74 and used them to construct a novel aging clock. Our clock predicted age with a root mean squared error of 7.69 years, a median absolute error of 5.69 years and a correlation of 0.83. Moreover, by comparing our chromatin accessibility data to matched transcriptomic profiles, we show that the genomic sites selected by our clock drive changes in transcription during aging. This chromatin accessibility clock could therefore be used to better understand the mechanisms driving the process of aging and evaluate anti-aging interventions. Overall design: Chromatin accesibility and transcriptomics profiles from PBMCs of human donors