Table 2.
End points examined | Design | Cell type | Findings | Limitations of method | Reference |
---|---|---|---|---|---|
Apoptosis and vascular injury | -Immunomagnetic isolation and staining of CD146 + vWF+, UEA-1+ CD133-cells -Syto16+CD45-CD31+CD146+ cells isolated by flow cytometry or by a fluorescence-activated cell sorter and electron microscopy imaging |
CECs | -Opposite correlation with HbA1c in T1DM and T2DM -Increased in diabetes -Have apoptotic cell features |
-Incomplete separation from EPCs -Low circulating levels -No functional or biochemical studies -No single marker to identify -Site of endothelial damage unknown -The correlation with HbA1c is unclear |
[23-30] [31••] [32] |
Apoptosis and vascular injury | -Flow cytometry analysis of platelet-poor plasma, apoptotic microparticles by Annexin V staining -TF-dependent procoagulant assay, ELISA, or prothrombinase assay -EC identity based on CD31/CD144 expression |
EMPs | -Involved in cardiovascular diseases, inflammation, and coagulation -Cardiovascular risk marker in diabetes |
-Incomplete standardization -Low circulating levels -No functional or biochemical studies -In diabetes, released by large panel of cells |
[33-37] |
Adhesion and vascular regeneration | -Cells with CD34+ or CD133+ and with KDR+ or CD31+ isolated by flow cytometry -EPC ex vivo cell culture protocol (≥ 14 days) in endothelial differentiation medium |
EPCs | -Reduced or impaired in cardiovascular disease and diabetes -Form colonies, adhere to a monolayer of ECs in culture -Diabetic PBMCs can be differentiated into EPCs |
-Incomplete separation from CECs/HSCs -Poor or incomplete standardization, -No functional/biochemical studies -Semiquantitative analysis -Low circulating levels -Extrapolation from in vivo environment |
[38-40] [41••] |
Adhesion, apoptosis, AGE/RAGE and ROS, endothelial activation/dysfunction, vascular inflammation/injury |
-CD146+ ECs collected by angiocatheterization and enriched by immunomagnetic isolation -RNA amplified for quantitative PCR and microarray analysis -ECs fixed and then stained with vWF+ and desired markers for protein analysis |
human aortic ECs/ human venous ECs |
-Patients own aorta and/or venous ECs are sampled and showed ECs activation in chronic inflammation (e.g., in diabetes, cardiovascular diseases, sleep apnea, lupus and aging) |
-Sampling of aorta replaced by venous for minimally invasive and repeatable sampling -Venous ECs give important, but incomplete information -RNA amplification needed for quantitative analysis |
[42-44] [45] [46-49] |
AGE advanced glycation end products; CECs circulating endothelial cells; ECs endothelial cells; ELISA enzyme-linked immunosorbent assay; EMPs endothelial microparticles; EPCs endothelial progenitor cells; HbA1c hemoglobin A1c; HSCs hematopoietic stem cells; PBMCs peripheral blood mononuclear cells; PCR polymerase chain reaction; RAGE receptor for advanced glycation end products; ROS reactive oxygen species; T1DM type 1 diabetes; T2DM type 2 diabetes; νWF von Willebrand factor.