Expression data from human bone marrow hematopoietic stem cells

In the human hematopoietic system, aging is associated with decreased bone marrow cellularity, decreased adaptive immune system function, and increased incidence of anemia and other hematological disorders and malignancies. Recent studies in mice suggest that changes within the hematopoietic stem cell (HSC) population during aging contribute significantly to the manifestation of these age-associated hematopoietic pathologies. While the mouse HSC population has been shown to change both quantitatively and functionally with age, changes in the human HSC and progenitor cell populations during aging have not yet been characterized. Gene expression profiling revealed that aged human HSC transcriptionally up-regulate genes associated with cell cycle, myeloid lineage specification, and myeloid malignancies. These age-associated alterations in the frequency, function, and gene expression profile of human HSC are significantly similar to those changes observed in mouse HSC, suggesting that hematopoietic aging is an evolutionarily conserved process.