Circulating stem and progenitor cells as markers of inflammation, endothelial regeneration, and prediction of vascular complications in metabolic syndrome and type 1 and 2 diabetes mellitus
The aim of this study was to identify mesenchymal stem cells (MSC), hematopoietic stem cells (HSC), mature endothelial cells, and endothelial progenitor cells (EPC) in the blood of healthy volunteers, patients with metabolic syndrome, and type 1 and 2 diabetes mellitus as new, informative cellular markers of vascular complications, endothelial regeneration, and inflammation. Methods. The diagnosis was confirmed by general clinical, biochemical, coagulometeric and ELISA studies; multi-parameter cytometric assay was used for evaluation of antigen expression. Results. Changes in the count of MSC, HSC, mature endothelial cells, and endothelial progenitor cells in blood of patients with metabolic syndrome and type 1 and 2 diabetes depended on the type of pathology. We propose using endothelial cells of myeloid (CD45<sup>-</sup>CD14<sup>+</sup>CD34<sup>+</sup>CD309<sup>+</sup>CD144<sup>+</sup>CD31<sup>+</sup>) and non-myeloid origin (CD45<sup>-</sup>CD14<sup>-</sup>CD34<sup>+</sup>CD309<sup>+</sup>CD144<sup>+</sup>CD31<sup>+</sup>), CD309<sup>+</sup>-endothelial cells, and MSCs with the CD44<sup>+</sup>CD73<sup>+</sup>CD90<sup>+</sup>CD105<sup>+</sup> phenotype as nonspecific markers of endothelial damage in presence of diabetic symptoms. Furthermore, HSCs (CD45<sup>+</sup>CD34<sup>+</sup>) can be used as a valuable diagnostic and prognostic marker of inflammation. Conclusions. It is relevant to evaluate EPCs of non-bone marrow localization (CD31<sup>+</sup>CD309<sup>+</sup>CD144<sup>+</sup>) and bone marrow localization (CD34<sup>+</sup>CD309<sup>+</sup>) and EPCs with a high regenerative potential (CD45<sup>-</sup>CD34<sup>+</sup>CD31<sup>+</sup>CD144<sup>+</sup>) in the blood of patients with type 1 and 2 diabetes to confirm the presence of vascular damage and predict development of complications. Circulating, in vitro colony-forming EPCs (CD45<sup>-</sup>CD34<sup>+</sup>CD31<sup>+</sup>) are recommended as a differential marker for inhibition of endothelial regeneration in type 2 diabetes.