Bone Marrow-Derived Aldehyde Dehdrogenase Expressing Cells Possess Endothelial Progenitor Function in Addition to Hematopoietic Repopulating Ability and Aid in Blood Flow Recovery after Acute Ischemic Injury

• Published in: Blood 2005-11, Vol.106 (11), p.2663-2663
• Main Authors: Capoccia, Benjamin J., Wirthlin, Louisa, Shepherd, Rebecca, O'Dell, Kevin, Nolta, Jan A., Link, Daniel C., Hess, David A.
• Format: Article
• Language: English
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood.V106.11.2663.2663

Human bone marrow (BM) is a heterogeneous compartment of stem and progenitor cells from hematopoietic, endothelial, and mesenchymal lineages. These cell types may be recruited to sites of new blood vessel formation including ischemic tissues and tumor microenvironments. Prospective isolation of cells with neoangiogenic function has proven difficult due to the lack of surface markers specific to endothelial precursors. We have previously characterized a novel population of reconstituting hematopoietic stem and progenitor cells from human umbilical cord blood by selection of cells with high aldehyde dehydrogenase (ALDH) enzyme activity (Hess, Blood 2004). In the current study, we isolated ALDHhi and ALDHlo cells with low side scatter properties from human BM, and assayed for hematopoietic and angiogenic function. The ALDHhi subset represented 0.8±0.2% of total nucleated BM cells whereas ALDHlo cells were 10-fold more abundant (8.2±1.3%, n=5). ALDHhi cells highly expressed cell surface molecules associated with hematopoietic (89.1±1.3% CD45+, 70.5±7.5% CD117+) and endothelial progenitor function (76.5±1.8 CD34+, 72.0±7.6% CD133+). ALDHhi cells also expressed mature macrophage/monocyte markers (24.2±3.9% CD11b+), whereas mature lymphocyte markers (3.5±0.5% CD3+, 5.1±0.3% CD19+), and mature endothelial cell markers (2.6±0.8% VEGFR2+) were rare. The corresponding ALDHlo population demonstrated a significantly reduced frequency of cells expressing a primitive phenotype (8.6±1.5% CD34+, 1.4±0.4% CD117+, 2.2±0.6% CD133+, p