Young and Old HSCs differentially respond to high TPO conditions.
Hematopoietic stem cells decline their repopulating potential along with aging especially under proliferative conditioins including following bone marrow transplantation. A mechanism underlying dysfunctional HSC is still elusive. Here we compared the expression profile and chromatin accessibility of freshly isolated HSCs or TPO-stimulated HSCs either from young or old mice by RNA-seq and ATAC-seq. Many of open chromatin regions (OCRs) characteristic for old HSCs were retained accessible even after stimulation, but a part of OCRs with lower accessibility in old HSCs become accessible after TPO stimulation, which might explain the rejuvenating function of TPO.