Introduction. Due to a set of unique properties, for example, the ability to differentiate into different types of connective tissue cells, mesenchymal stem cells (MSCs) are attracting more and more attention from researchers. In 2001, stem cells were found in the stromal-vascular fraction of adipose tissue, which, unlike bone marrow MSCs, show a higher tissue density, grow faster, and are available in large numbers when collected from a small amount of adipose tissue. Currently, a large number of studies are devoted to the study of the morphology and immunophenotype of subcutaneous and visceral adipose tissue stem cells (ASSCs) due to the possibility of easy cell production. Experimental work aimed at studying MSCs of cardiac localization is currently insufficient. Objective: to evaluate the immunophenotype of adipose tissue stromal cells isolated from epicardial and perivascular fat depots in patients with coronary heart disease and acquired heart defects. Materials and methods. The study included 5 patients with ischemic heart disease and 5 with acquired heart disease. The average age is 64.5±2.5 years. All patients had indications for open heart intervention - direct myocardial revascularization by coronary bypass grafting (CABG) or heart valve surgery. SCZhT from subcutaneous, epicardial and perivascular VT biopsies (3-5 years) obtained from patients during surgery (CABG or correction of heart defects) and isolated according to the method of Zeng G. [Zeng G. et al., 2013] . When cells grew to 80–90% confluence, they were digested with 0.25% trypsin and subjected to continuous cell growth and proliferation for subsequent experimental analyses. Flow cytometry analysis was performed on passage 2 cells. Results: The obtained results showed that the MSC culture of the 2nd passage was characterized by increased expression of CD73, CD90, CD105 antigens. Approximately 90% of passage 2 cells derived from epicardial adipose tissue (EAT) and perivascular adipose tissue (PVAT) from a patient with coronary heart disease (CHD) expressed classical MSC markers (CD73, CD90, CD105). In EAT cell culture in a patient with acquired heart disease (ACD), we observed a lower level of co-expression of the main markers of stem cells, in contrast to a patient with CHD (CD90 and CD105 about 61% of cells, and CD90 and CD73 - 58.72%) . The percentage of the studied stem markers on cells isolated from PVAT in a patient with heart disease did not differ significantly from the level of expression of these markers in a patient with coronary artery disease. The level of CD34 expression varied depending on the localization of VT and the disease: thus, in patients with coronary artery disease, the level of CD34 did not exceed 3.5% in both epicardial and perivascular VT. At the same time, a higher percentage of CD34 (32.32%) was found in the epicardial adipose tissue of a patient with PPS. It should be noted that in addition to the main population, both in the EAT culture and in the PVAT, there were 2 minor ones: 1 - CD 90- CD 105+ CD 34-/+ CD 73+ - presumably endothelial population, 2 - CD 90+ CD 105- CD 34- CD 73- - the smallest population. Conclusion: In the early stages of cultivation, cells of the stromal-vascular fraction isolated from epicardial and perivascular adipose tissue express surface markers characteristic of adipose tissue stem cells.
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