3.
Characteristics of human EC-like cells, EOCs and CECs
| EC-like cells | EOCs | CECs |
|---|---|---|
| (EPCs, ECs, CFU-ECs, CACs, ATs, early outgrowth CE-EPCs, CMMCs and early EPCs) | (EPCs, ECs, CFU-ECs, BOECs, ECFCs, EPDCs, EC-like, late EPCs, late endothelial outgrowth) | (Circulating endothelial cells) |
| 1. Generated after 4–21 days in culture | 1. Appear after > 7 days in culture | 1. Low proliferative ECs, shed from the vascular wall into the circulation |
| 2. Round (pancake) to spindle shaped appearance; no typical confluent monolayer | 2. Typical polygonal cells in a confluent cobblestone monolayer | 2. Have a similar phenotypical profile compared to EOCs |
| 3. Express endothelial and haematopoietic markers (e.g. CD45, CD14) | 3. Express CD31, CD34, CD105, CD146, VE-Cadherin, VEGFR-2, but not the haematopoietic surface markers CD133, CD14 or CD45 | 3. Do not express haematopoietic markers and have no apparent haematopoietic potential or function |
| 4. Bind UEA-1 lectin and take up LDL | 4. Bind UEA-1 lectin and take up LDL | |
| 5. Maintain haematopoietic potential and/or functions | 5. Have no apparent haematopoietic potential | |
| 6. Have low proliferative potential | 6. Bear high proliferative potential | |
| 7. Do not generate vascular tubes in vitro in matrigel | 7. Generate vascular tubes in vitro/in vivo in matrigel | |
| 8. Improve neovascularization in vivo | 8. Improve neovascularization in vivo | |
| 9. Originate from CD45+ haematopoietic lineage cells (CD34+CD45+, CD133+CD45+, CD34−CD45+, CD14+CD45+) | 9. Originate from CD45−CD133−CD34+ cells, bone marrow (*) and probably the vascular wall |
CFU-ECs [77, 159, 160]: colony forming unit of endothelial cells; ATs [161]: attaching cells; CACs [47]: circulating angiogenic cells; CE-EPCs [76]: culture expanded endothelial progenitor cells; CMMCs [162]: culture modified mononuclear cells; EOCs [58]: endothelial outgrowth cells; BOECs [163]: blood EOCs; ECFCs [79]: endothelial colony forming cells; EPDCs [37]: endothelial progenitor-derived cells; CECs [163]: circulating endothelial cells, (*) [94]: bone marrow multipotent adult progenitor cells (MAPCs) have been suggested to be the earliest EOC precursors.