{Reference Type}: Journal Article
{Title}: Runx1+ vascular smooth muscle cells are essential for hematopoietic stem and progenitor cell development in vivo.
{Author}: Gonzalez Galofre ZN;Kilpatrick AM;Marques M;Sá da Bandeira D;Ventura T;Gomez Salazar M;Bouilleau L;Marc Y;Barbosa AB;Rossi F;Beltran M;van de Werken HJG;van IJcken WFJ;Henderson NC;Forbes SJ;Crisan M;
{Journal}: Nat Commun
{Volume}: 15
{Issue}: 1
{Year}: 2024 Feb 23
{Factor}: 17.694
{DOI}: 10.1038/s41467-024-44913-z
{Abstract}: Hematopoietic stem cells (HSCs) produce all essential cellular components of the blood. Stromal cell lines supporting HSCs follow a vascular smooth muscle cell (vSMC) differentiation pathway, suggesting that some hematopoiesis-supporting cells originate from vSMC precursors. These pericyte-like precursors were recently identified in the aorta-gonad-mesonephros (AGM) region; however, their role in the hematopoietic development in vivo remains unknown. Here, we identify a subpopulation of NG2+Runx1+ perivascular cells that display a sclerotome-derived vSMC transcriptomic profile. We show that deleting Runx1 in NG2+ cells impairs the hematopoietic development in vivo and causes transcriptional changes in pericytes/vSMCs, endothelial cells and hematopoietic cells in the murine AGM. Importantly, this deletion leads also to a significant reduction of HSC reconstitution potential in the bone marrow in vivo. This defect is developmental, as NG2+Runx1+ cells were not detected in the adult bone marrow, demonstrating the existence of a specialised pericyte population in the HSC-generating niche, unique to the embryo.