Comparative study of cultured human bone marrow and adipose tissue (lipoaspirate) mesenchymal stem cells was carried out. The main morphological parameters, proliferative activity, expression of surface and intracellular markers of these cells were characterized. Flow cytofluorometry and histological staining showed that both cell types exhibited similar expression of CD105, CD54, CD106, HLA-I markers, were positively stained for vimentin, ASMA, collagen-1, and fibronectin, but not HLA-DR, CD117, and hemopoietic cell markers. The cells underwent differentiation into adipocytes and osteoblasts under appropriate conditions of culturing. Incubation under neuroinductive conditions led to the appearance of a cell population positively stained for type III beta-tubulin (neuronal differentiation marker).

We studied the effect of reduced oxygen content (5%) on the phenotype and functional activity of cultured human mesenchymal stem cells. The expression of main immunophenotypic markers for mesenchymal stem cells (CD13, CD29, CD44, CD73, CD90, CD105, and HLA-I) remained practically unchanged under conditions of hypoxia. The expression of cell adhesion molecules (CD54 and CD106) increased during coculturing of mesenchymal stem cells and hemopoietic stem cells. These changes were accompanied by increased production of hemopoietins (interleukin-6 and interleukin-8) and enhanced colony-forming capacity of hemopoietic stem cells. Coculturing of mesenchymal stem cells and hemopoietic stem cells during hypoxia was followed by increased formation of hemopoietic islets and intensive production of interleukin-6, interleukin-8, and vascular endothelial growth factor (compared to cultures under normoxic conditions).

We present a technology of culturing of human mesenchymal stem cells under conditions excluding the presence of animal sera or additional growth factors, but preserving high proliferative potential and the capacity of these cells to multilineage differentiation. Human umbilical serum was used as the alternative material. We found that in the presence of human umbilical serum mesenchymal stem cells more effectively proliferate and retain their differentiation capacity. The proposed technology yields 109-1010 morphologically and functionally identical cells.