Peripheral Blood “Endothelial Progenitor Cells” Are Derived From Monocyte/Macrophages and Secrete Angiogenic Growth Factors

Abstract

Our findings suggest that acetylated LDL(+)ulex-lectin(+) cells, commonly referred to as EPCs, do not proliferate but release potent proangiogenic growth factors. The majority of acetylated LDL(+)ulex-lectin(+) cells are derived from monocyte/macrophages. The findings of low proliferation and endothelial differentiation suggest that their angiogenic effects are most likely mediated by growth factor secretion. These findings may allow for development of novel angiogenic therapies relying on secreted growth factors or on recruitment of endogenous monocytes/macrophages to sites of ischemia.

Better vascular engraftment and function in pancreatic islets transplanted without prior culture

“…Monocytes and tissular macrophages seem strongly involved in adult angiogenesis due to their local secretion of metalloelastases, which cause the formation of capillary lumens through local tunnelling in the parenchyma [42,43]. Monocytes and macrophages also contribute to the local pool of endothelial progenitor cells [44]. The role of these cells in adult angiogenesis, including that in the revascularisation of pancreatic islets, has recently been demonstrated [45,46].…”

Chemokines in tumor development and progression

“…CCR2, a specific receptor for CCL2, is expressed by endothelial cells and CCL2 exerts its angiogenic activity in a membrane type 1 (MT1)-MMP-dependent manner [63] (Figure 2). CXCL4 and interferon-inducible ELR-negative CXC chemokines such as CXCL9, CXCL10, and CXCL11 inhibit the angiogenesis induced by ELR-positive CXC Mukaida 11 chemokines, VEGF, and bFGF [66,67]. The anti-angiogenic effects of these chemokines are mediated by a common receptor, CXCR3 (Figure 2).…”

Endothelial progenitor cells: Implications for cardiovascular disease

“…Already these variations in the coating strategy may have an influence on the results obtained by cell culture with respect to cell number, cell phenotype, and cell function. Another important factor regulating the fate of the plated cells is the cell culture media ranging from EBM-2 (23-25), medium-199 (22,26,27), to x-vivo-20 (28) as basal media, and 20% fetal calf serum (1), brain extract (1,26), to commercial available single quots of VEGF, insulin-like growth factor (IGF), basic fibroblast growth factor (23,25) as supplements. An identification criteria often used for EPCs in the culture of MNCs for 4 or 7 days is the double-positive staining of EPCs for endothelial-specific lectin (e.g., Ulex europaeus agglutini-1) and Dil-labeled acetylated low-density lipoproteins (Ac-LDL) (26,29,30).…”