Post-GWAS functional analysis identifies CUX1 as a regulator of p16INK4a and cellular senescence

Accumulation of senescent cells with age is believed to be an important driver of aging and age-related diseases. However, the underlying mechanisms and the signaling pathways that regulate senescence remain elusive. In this report, we couple high throughput (HTP) mapping of disease-associated functional SNPs (fSNPs) with proteomics analysis of fSNP-binding regulatory proteins to dissect the CDKN2A/B locus, a locus known to be associated with multiple age-related diseases, as well as overall human longevity. We demonstrate that the homeodomain transcription factor CUX1 specifically binds to a fSNP (rs1537371) associated with atherosclerosis within the CDKN2A/B locus. Although it binds at a considerable distance (> 100 kb), CUX1 is shown to regulate the CDKN2A/B encoded genes p14ARF, p15INK4b, p16INK4a, and ANRIL in endothelial cells (ECs). In-depth analysis demonstrates that endothelial CUX1 expression correlates with telomeric length and is induced by both DNA-damaging agents and oxidative stress. Moreover, induction of CUX1 expression triggers both replicative and stress-induced premature senescence via activating p16INK4A expression. Consistent with these findings, we also detect elevated expression of CUX1 and p16INK4A in the plaques of patients with carotid artery disease. Our HTP strategy therefore identifies CUX1 as a regulator of p16INK4A expression and endothelial senescence and a potential therapeutic target for atherosclerosis and other age-related diseases. mRNA profiles from human endothelial cells treated with a scrambled siRNA control or a siRNA targeting human CUX1