ABSTRACT
OBJECTIVES: The objective of this study was to determine whether the number of endothelial progenitor cells (EPCs) and circulating angiogenic cells (CACs) in peripheral blood was associated with the presence and severity of coronary artery disease (CAD) in patients undergoing coronary angiography. BACKGROUND: Previous studies have suggested an inverse relationship between levels of circulating EPCs/CACs and the presence of CAD or cardiovascular risk factors, whereas other studies have observed increased numbers of EPCs in the setting of acute ischemia. However, the criteria used to identify specific angiogenic cell subpopulations and methods of evaluating CAD varied in these studies. In the present study, we used rigorous criteria to identify EPCs and CACs in the blood of patients undergoing coronary angiography. METHODS: The number of EPCs and CACs were measured in the blood of 48 patients undergoing coronary angiography. Patients with acute coronary syndromes were excluded. RESULTS: Compared with patients without angiographically significant CAD, the number of EPCs was increased (1.11 +/- 2.50 vs. 4.01 +/- 3.70 colonies/well, p = 0.004) and the number of CACs trended higher (175 +/- 137 vs. 250 +/- 160 cells per mm(2), p = 0.09) among patients with significant CAD. The highest levels of EPCs were isolated from patients subsequently selected for revascularization (5.03 +/- 4.10 colonies/well). CONCLUSIONS: In patients referred for coronary angiography, higher numbers of EPCs, and a trend toward higher numbers of CACs, were associated with the presence of significant CAD, and EPC number correlated with maximum angiographic stenosis severity. Endothelial progenitor cell levels were highest in patients with CAD selected for revascularization.
Subject(s)
Coronary Angiography , Coronary Artery Disease/blood , Coronary Artery Disease/pathology , Endothelial Cells/pathology , Stem Cells/pathology , Cell Count , Cells, Cultured , Coronary Artery Disease/diagnostic imaging , Coronary Artery Disease/physiopathology , Humans , Neovascularization, Physiologic , Severity of Illness IndexABSTRACT
Circulating endothelial progenitor cells (EPCs) are thought to contribute to angiogenesis following vascular injury, stimulating interest in their ability to mediate therapeutic angiogenesis. However, the number of EPCs in the blood is low, limiting endogenous repair, and a method to rapidly mobilize EPCs has not been reported. In this study, healthy donors were mobilized sequentially with the CXCR4 antagonist, AMD3100, and G-CSF. The number of EPCs and circulating angiogenic cells (CACs) in the blood and pheresis product was determined and the angiogenic capacity of each cell population assessed. Compared with baseline, treatment with AMD3100 or G-CSF increased the number of blood CACs 10.0-fold +/- 4.4-fold and 8.8-fold +/- 3.7-fold, respectively. The number of EPCs in the blood increased 10.2-fold +/- 3.3-fold and 21.8-fold +/- 5.4-fold, respectively. On a percell basis, CACs harvested from G-CSF-mobilized blood displayed increased in vivo angiogenic potential compared with AMD3100-mobilized CACs. Mobilized EPCs displayed a greater proliferative capacity than EPCs isolated from baseline blood. Both CACs and EPCs were efficiently harvested by leukapheresis. Cryopreserved CACs but not EPCs retained functional activity after thawing. These data show that AMD3100 is a potent and rapid mobilizer of angiogenic cells and demonstrate the feasibility of obtaining and storing large numbers of angiogenic cells by leukapheresis.
Subject(s)
Anti-HIV Agents/administration & dosage , Blood Donors , Endothelial Cells/cytology , Granulocyte Colony-Stimulating Factor/administration & dosage , Hematopoietic Stem Cell Mobilization , Heterocyclic Compounds/administration & dosage , Neovascularization, Physiologic , Stem Cells/cytology , Animals , Anti-HIV Agents/adverse effects , Benzylamines , Cell Proliferation , Cryopreservation/methods , Cyclams , Endothelial Cells/physiology , Female , Hematopoietic Stem Cell Mobilization/adverse effects , Hematopoietic Stem Cell Mobilization/methods , Heterocyclic Compounds/adverse effects , Humans , Injections, Subcutaneous , Leukapheresis/methods , Male , Mice , Mice, Inbred NOD , Mice, SCID , Neovascularization, Physiologic/physiology , Stem Cell Transplantation/methods , Stem Cells/physiologyABSTRACT
There is compelling evidence that circulating angiogenic cells exist that are able to home to sites of vascular injury and stimulate angiogenesis. However, the number of angiogenic cells in the blood is low, limiting their delivery to sites of ischemia. Treatment with certain cytokines may mobilize angiogenic cells into the blood, potentially circumventing this limitation. Herein, we show that treatment with granulocyte colony-stimulating factor (G-CSF) or AMD3100, a novel CXCR4 antagonist, significantly stimulated angiogenesis in a murine model of acute hindlimb ischemia. The kinetics of angiogenic-cell mobilization by these agents appears to be distinct, with more rapid revascularization observed in AMD3100-treated mice. Combination treatment with G-CSF and AMD3100 resulted in the earliest and most complete recovery in blood flow to the ischemic hindlimb. Adoptive transfer of mobilized blood mononuclear cells, while potently stimulating angiogenesis, did not result in the significant incorporation of donor cells into the neoendothelium. Cell-fractionation studies showed that it is the monocyte population in the blood that mediates angiogenesis in this model. Collectively, these data suggest that monocytes mobilized into the blood by G-CSF or AMD3100 stimulate angiogenesis at sites of ischemia through a paracrine mechanism.
