Leptin Receptor, a Surface Marker for a Subset of Highly Engrafting Long-term Functional Hematopoietic Stem Cells

ABSTRACT: The hematopoietic system is sustained by a rare population of hematopoietic stem cells (HSCs), which emerge during early fetal development and then reside in the hypoxic niche of the adult bone marrow microenvironment. Although leptin receptor (Lepr)-expressing stromal cells are well-studied as critical regulators of murine hematopoiesis, the biological implications of Lepr expression on HSCs remain largely unexplored. We hypothesized that Lepr+HSCs are functionally different from other HSCs. Using in vitro and in vivo experimental approaches, we demonstrated that Lepr further differentiates SLAM HSCs into two distinct populations; Lepr+HSCs engrafted significantly higher than Lepr-HSCs and self-renewed more extensively as noted in secondary transplants. To determine how molecular pathways and gene expression profiles affect their functional differences, we performed bulk RNA-sequencing on purified Lepr+HSC/MPP and Lepr-HSC/MPP cells. Our results showed that Lepr+HSCs were characterized by a proinflammatory transcriptomic profile enriched for Type-I Interferon and Interferon-gamma (IFN-γ) response pathways, which are known to be critical for the emergence of HSCs in fetal life. Gene set analyses indicated that Lepr+HSCs were more highly enriched for genes associated with long-term HSCs whereas Lepr-HSCs’ expression profiles were more closely related to progenitors. We conclude that although Lepr+HSCs represent a minor subset of HSCs, they are highly engrafting cells that possess embryonic-like transcriptomic characteristics, and that Lepr can serve as a useful marker for functional long term HSCs, which may have potential clinical applicability.

ORGANISM(S): Mus musculus

PROVIDER: GSE158393 | GEO | 2020/10/30

REPOSITORIES: GEO