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It has been shown that hypoxia (5% 02) and fibroblast growth factor bFGF reduce the doubling time of bone marrow mesenchymal stem cells under their cultivation in vitro that indicates an increase in cell culture proliferation. It has been found out that low concentrations of O2 and factor bFGF added to the cell culture medium increase an expression of abcg2 gene and its gene protein, ABCG2 transport gene, in mesenchymal stem cells. These events potentiate the effects of hypoxia observed in mesenchymal stem cells. We revealed that blocking of ABCG2 protein functional activity led to increased generation of reactive oxygen species in mesenchymal stem cells. The effect of hypoxia and/or bFGF on protein profile of mesenchymal stem cells was studied. The results represented in this work together with previous data proved a link between ABCG2 protein expression, its activity and maintenance of viability and proliferative activity of mesenchymal stem cells cultivated under hypoxia. ABCG2 acts as protector.

The human adipose-derived mesenchymal stem cells was shown to be hepatic differentiated under influence of inductor factors. The differentiation of MSCs was induced by fibroblast growth factor-4, hepatocyte growth factor, oncostatin M and dexamethasone. The influence of quercetin on the hepatic differentiation of MSCs in culture was investigated. The adding quercetin into induction medium (1 or 10 mmol/l) enhanced the manifestation of signs of hepatic differentiation MSCs such as urea secretion, cytokeratin 19 and a-fetoprotein synthesis. Quercetin modulating action on the CYP1A — cytochrome P450 activity in differentiated cells was found. MSCs which was differentiated in the presence of quercetin had a higher viability and resistance to oxidative stress.

Currently, biophysical mechanisms of stress signaling transduction became an object of consideration of researchers in connection with the urgent necessity to develop new techniques to enhance the sustainability and productivity of agricultural crops. The development of sensitive methods for the determination of cyclic guanosine monophosphate (cGMP) and comparative analysis of cGMP-dependent events in biological systems has contributed to progress in the understanding of the functioning of cGMP in plant cells. Currently, it is shown that cGMP as a secondary mediator is involved in such vital processes of growth and development of plants as seed germination, cell division, development of chloroplasts, flowering and regulation of stomatal movements. This review summarizes the available data in the literature about the role of cGMP in the responses of plant organisms to the action of stress factors of abiotic and biotic nature and its interaction with other intracellular mediators. With the use of existing ideas about the biophysical mechanisms of stress in plants, the basic elements of cGMP-dependent signal transduction system in a plant cell are considered.

In order to evaluate the toxic effect of silver (AgNP) and titanium dioxide (TiO2) nanoparticles their influence on the expression of genes of biomarkers of inflammatory responses and apoptosis in human lymphocytes was studied. An increase in the IL-6, IL-8, TNF-α and p53 genes expression in the concentration range of silver and titanium dioxide nanoparticles of 10-40 μk g/ml was found. Increased expression of IL-6, IL-8, TNF-α and p53 genes under the nanoparticles action indicates the stimulation of the immune system and of apoptosis, respectively.

The influence of FGF2 on the efficiency of cardiomyocytes differentiation of mesenchymal stem cells (MSC) of bone marrow induced by 5-azacetidine (5-aza) was studied. The effect of FGF2 developing by the 14th day after the combined action of a differentiating agent and growth factor was manifested in an increase in Mef2A, Mef2D and gene transcription and a rise of ionized Ca2+ concentration in cytoplasm keeping cell viability and proliferation activity. In the presence of FGF2 this approach provided cardiomyogenesis and the increase in the formation of early precursors of cardiomyocytes.