Structure and synthesis of Erythropoietin: Erythropoietin (EPO) is a glycoprotein hormone.Recombinant Erythropoietin (Epoetin): Human recombinant erythropoietin is characterised as a factor which stimulates differentiation and proliferation of erythroid precursor cells, and as a tissue protective factor.Anti-ischemic effects of recombinant Erythropoietin: Erythropoietin is one of the most perspective humoral agents which are involved in the preconditioning phenomenon.Erythropoietin receptors and signal transduction pathways: Erythropoietin effects on cells through their interconnection with erythropoietin receptors, which triggers complex intracellular signal cascades, such as JAK2/STAT signaling pathway, phosphatidylinositol 3-kinase (PI3K), protein kinase C, mitogen-activated protein kinase (MAPK), and nuclear factor (NF)-κB signaling pathways.Mechanisms of the effect of Erythropoietin on hematopoietic and non-hematopoietic cells and tissues: In addition to regulation of haemopoiesis, erythropoietin mediates bone formation as it has an effect on hematopoietic stem cells and osteoblastic niche, and this illustrates connection between the processes of haematopoiesis and osteopoiesis which take place in the red bone marrow.The effect of Erythropoietin on mesenchymal stem cells and process of bone tissue formation: Erythropoietin promotes mesenchymal stem cells proliferation, migration and differentiation in osteogenic direction. The evidence of which is expression of bone phenotype by cells under the influence of EPO, including activation of bone specific transcription factors Runx2, osteocalcin and bone sialoprotein.Conclusion: Erythropoietin has a pleiotropic effect on various types of cells and tissues. But the mechanisms which are involved in the process of bone tissue restoration via erythropoietin are still poorly understood.

We studied the expression of transcription factors RUNX2 and Osterix after addition of a concentrate of osteogenic-conditioned medium to the culture medium for osteogenic differentiation of mesenchymal stem cells (MSC). The obtained concentrate of osteogenic-conditioned medium containing a complex of bioactive substances with a molecular weight >10 kDa provided MSC differentiation into osteoblasts, which was confirmed by high level of expression of transcription factors RUNX2 and Osterix in comparison with the negative control. The highest expression of transcription factor Osterix was revealed on day 14 of MSC culturing in the presence of osteogenic supplement StemPro (positive control) and the studied concentrate of osteogenic-conditioned medium.

We studied the influence of the characteristics of oxide porous coatings on osteogenesis and integration of new bone tissue and titanium implant surface in the ectopic osteogenesis test. Implants with coating with pore size 2-20 μ exhibit better osteogenic and osteoconductive characteristics than implants with homogenous surface and smooth relief (pore size 0.5-5.0 μ). Physical characteristics of the surface of the material along with chemical composition of the coating are essential for the formation of bone tissue and its integration with the implant.

Continuous monitoring of multipotent mesenchymal stromal cells (MMSCs) is a promising tool that could be used in cellular biology, environmental research and biotechnology to study in vitro real-time morphology and behavioural response of stem cells alone, as well at contacts with other cells and for controlling a sustainable production of scaffolds for tissue engineering. The in vitro processes of human adipose-derived MMSCs (hAMMSCs) morphology, motility, cell division, and secretion were studied by means of Cell-IQ v2 MLF (CM Technologies Oy, Finland) integrated phase-contrast microscopic platform for a continuous real-time Environmental Research, Engineering and Management 2018/74/3 surveillance imaging of living cells. 70 μL suspension (5×10 4 viable karyocytes) of the cells was applied into the centre of the wells of 12-well plastic plates, and cells were allowed to adhere in a moist chamber for 120 min. Non-adherent cells were washed, and the wells were carefully filled with 1.5 mL of a nutrient medium DMEM/ F12 (1 : 1) without osteogenic additions. Cells were cultured for 14 days at 100% humidity in a 5% carbon dioxide atmosphere at 37°C until a monolayer formation. Digital images of cell culture growth were captured every 45 min. The cells were positively stained with alizarin red (osteoblasts), alcian blue (chondrocytes), or oil red (adipocytes). More than 95% of attached cells expressed CD73, CD90, and CD105 markers, mainly. Thus, the cells corresponded to the morphological criteria of MMSCs. The Cell-IQ system allowed establishing 182 μm/h linear velocity of free (until the cell contacts) motility of spindle or fibroblast-like cells. Maximum number of cells achieved 136 cells per field of view; 13-24% of cells divided each 1-3 h until a monolayer was formed. Chemokine cooperation between hAMMSCs and poor macrophages intermixture was proposed. Cell-IQ could be useful for in vitro real-time imaging of cell subpopulations and/or their response to biodegradable scaffolds and/or (micro)environmental factors.

The aim of this study was to evaluate the effect of treatment with valproic acid, erythropoietin, and dexamethasone on the anti-inflammatory and immunosuppressive activity of the secretome of adipose-derived multipotent mesenchymal stromal cells (MMSCs) in an in vitro experiment.Materials and methods. MMSCs were isolated from the fat of 6 healthy donors. The cells were grown in the culture up to passage 4. Then they were treated with valproic acid, erythropoietin or dexamethasone for 3 hours, washed from preparations, and incubated in a serum-free medium for 48 hours. Some of the cells were not treated with preparations. Supernatants from the cell cultures were concentrated by ultrafiltration, and protein standardization was performed using a nanophotometer. Then the supernatants were sterilized and added to mononuclear cells from peripheral blood of 8 healthy donors. The mononuclear cells were isolated by Ficoll density gradient centrifugation according to the standard protocol. Concentrations of TNFα, IL-2, IL-4, IL-6, IL-10, and IFNγ cytokines in 24-hour cultures and IL-9, IL-10, IL-17A, and IL-21 cytokines in 48-hour cultures were determined using multiplex analysis.Results. The production of IL-2, IL-6, TNFα, and IL-10 was reduced by the secretome of MMSCs treated with valproic acid. The production of IL-2, IL-6, and TNFα decreased during incubation of the mononuclear cells with the secretome of MMSCs treated with erythropoietin. The secretome of dexamethasone-treated MMSCs suppressed the production of IFNγ, IL-1β, IL-1ra, IL-2, IL-6, IL-9, IL-10, and IL-17A. No statistically significant differences were revealed in the production of IL-4, IL-5, IL-9, and IL-21.Conclusion. Among the studied inducers, dexamethasone enhanced the anti-inflammatory and immunosuppressive activity of MMSCs the most, which was manifested through the effect of their supernatants on peripheral blood mononuclear cells.