Bulk ATAC-seq of young HSCs and Selp high vs Selp low HSCs in pre-aged mice

Aging of hematopoietic stem cells (HSCs) is accompanied by changes in chromatin organization that precede and shape functional decline. P-selectin (Selp/CD62P) expression has been associated with inflammatory and stress-related hematopoietic states, yet how Selp expression relates to chromatin accessibility during the early stages of HSC aging remains largely unexplored. To address this, we performed bulk ATAC-seq on phenotypically defined HSCs isolated from young mice and from pre-aged mice, with the latter further subdivided according to surface Selp expression (Selp_high and Selp_low). Genome-wide accessibility profiling was used to identify regulatory elements and transcription factor–associated regions that distinguish early aging and Selp-associated heterogeneity within the HSC compartment. These data provide a resource for investigating epigenetic remodeling and regulatory priming associated with early hematopoietic stem cell aging.