The purpose of this paper was to examine the possibilities of engraftment, and to study the differentiation of the dissociated cells from the embryonic primordia of the spinal cord and the neocortex of Wistar rats, after their transplantation into the sciatic nerve of adult animals. The cell suspension obtained as a result of a dissociation of fragments of the cervical spinal cord and the anterior cerebral vesicle from rat fetuses at day 15 of development, was injected into the proximal segment of a previously damaged sciatic nerve. Using the immunocytochemichal marker of neural stem/progenitor cells (Msi-1) the transplanted cells were identified in the nerve trunks after 1 day after the operation. After 21 day some of these cells underwent differentiation into NeuN-immunopositive neurons, however their number was small. Thus, dissociated precursor cells from embryonic rat spinal cord and neocortex survive for three weeks under conditions of transplantation into the damaged nerve and retain the ability to differentiate into neurons, but the number is small. Most of the cells in the neocortex transplants, unlike those from spinal cord transplants, within 21 days after the operation were represented by the ependymocytes.

Transgenic tobacco plants overexpressing the PnEXPA3 gene of black poplar (Populus nigra), which encodes alpha-expansin, were obtained. The transgenic plants were characterized by increased size of epidermic and mesophyll cells of leaves. However, the size of leaves remained normal. Overexpression of the PnEXPA3 gene provided stimulatory effect only on the stem length. Other morphological traits of the transgenic plants remained unchanged.

Multipotent mesenchymal stromal (stem) cells (MMSCs) play an important role in the structural and functional balance in tissue remodeling and reparation. M MSCs synthesize broad spectrum of soluble mediators that includes molecules with immunomodulatory, anti-apoptotic, pro-angiogenic, hemoattrative, supportive and other effects. Microenvironmental factors, such as cell-tocell contacts, connective tissue matrix and the partial oxygen pressure can significantly affect the profile of MMSC-produced papracrine mediators, and therefore, change their biological activity. The present review analyses the recent data concerning MMSC paracrine profile and its modulation at hypoxia that is specific to its physiological mileu.

The review describes the mechanisms of hormonal, autocrine, paracrine and intracellular regulation in osteogenic differentiation of mesenchymal stem cells, the role of negative feedbacks in this process.

Critical limb ischemia is a syndrome that combines several peripheral artery diseases with different ethiology and pathogenesis but with similar prognosis, high morbidity and mortality. Possibility of surgical and conservative treatment of critical limb ischemia almost completely exhausted. Some hopes have arisen due to progress in cell technology. The article provides a critical analysis of pathogenic prerequisites of stem/progenitor cells for the treatment of patients with a critical limb ischemia in detail the basic results of preclinical and clinical studies on the safety and efficacy of cell technology. Unsolved problems and prospects of practical application are also discussed.

Acute myeloid leukemia is the most common acute leukemia affecting adults, and its incidence increases with age. Along with chromosomal translocations in leukemic cells mutations in the genes of receptor tyrosine kinases KIT and FLT3 were found with a high frequency. Here we show that transgenic progenitor of B-cells BAF3/FLT3-ITD are much more sensitive to the ribonuclease binase cytotoxic effects than the original BAF3 cells. The principal difference between BAF3/FLT3-ITD and the original BAF3 cells is the expression of FLT3-ITD oncogene, which leads to a change in the normal cell signaling pathways. Earlier, we described a similar effect for the cytotoxic action of binase on Kasumi-1 and FDC-P1-N822K cells, which express the activated KIT-N822K oncogene. Increased binase cytotoxicity toward the cells, expressing FLT3-ITD oncogene, suggests that, as in the case of FDC-P1 cells, transduced by KIT oncogene, the expression of an activated oncogene determines the sensitivity of cells to binase.

Cardiac function in Wistar male rats was assessed by ECG records for 28 days following exposure of the chest to γ-rays at a dose of 6 Gy, dose rate 4 Gy/min. The exposed rats experienced a moderate cardiac ischemia and a certain increase in the load on the atria. The use of clay of Kaluga deposit and mesenchymal stem cells reduced the adverse radiation effects.

It is shown, that tactics of treatment of acute marrow failure of radiant etiology is based, first of all, on measures of supporting, replaceable and stimulating therapy. The modern means, used for prophylactic and treatment of infectious complications, are resulted. Opportunities and restrictions of transfusion of donor thrombocytes and granulocytes, erythrocytes and chilled plasma are described. Therapeutic efficiency of transplantation of a bone marrow, cells of embryonic liver and stem cells of peripheral or umbilical cord blood is analyzed. It is shown, that the greatest prospects in perfection of the specialized medical aid at acute radiation syndrome are connected to complex application of interleukin-1beta, interleukin-3, granulocyte or granulocyte/macrophage colony stimulated factor, thrombopoietin and others cytokines.

The processes developing in various rat tissues after implantation of polymeric polyhydroxyalkanoate (PHA) film fragments with adsorbed autologous multipotent stromal (mesenchymal) cells of bone marrow origin (AMMSCBM), were studied by methods of light microscopy. After the implantation of PHA film with AMMSCBM, the number of blood vessels in the surrounding tissues was found to increase as a result of neoangiogenesis. In this case,AMMSCBM did not migrate and were not destroyed at the place of injection, but differentiated into the cells forming blood vessel structures. The processes of angiogenesis in the tissues around PHA implant, in turn, lead to development of a larger number of blood vessels in the granulations formed around the implanted foreign body, higher volume of granulations proper and subsequent development of a thicker capsule delimiting polymer implant.

Significant progress in the developmental biology of Drosophila is largely due to the improvement of methods of genetic manipulation and, in particular, development of ways to create mosaic organisms. The main characteristic of the mosaic organisms is the presence of genetically different populations of cells. For example, some tissues express a transgenic reporter gene that is absent in other cells of the body. This principle is used in a variety of the methods with the common name lineage tracing. The essence of these approaches is to perform the targeted changes in the genetic apparatus of progenitor cells that give rise to cell lines or organs and tissues. Genetic modification in progenitor cells, such as the ability to express a fluorescent protein, will be inherited by the next cell generations, and, as a result, the entire cell line or tissue will have a tag, which distinguishes it from the rest of the body. The lineage tracing methods allow tracking the cell generations, studying the cell proliferation process, tracing their origin and investigating the function of genes of interest in the development of a single tissue or organ. We have designed an approach to selectively label germ line or somatic cells in the gonads of Drosophila.

Cell migration is an important fundamental process. It occurs over the embryonic development, immune system responses, reparation and regeneration of damaged tissues. Abnormal migration is characteristic for many disorders such as cancer metastasis. Both external and intrinsic factors control directionality of cell movement. In case the external factors are of chemical nature the directed migration is called chemotaxis. Here we review current models of directional sensing in mesenchymal cells and compare them to well studied mechanisms of amoebal chemotaxis.

During last two decades multipotent mesenchymal stromal (stem) cells (MMSCs) were not only identified and isolated from many tissues, but their immunopriviledge and immunosupressive potential along with high proliferative activity and multilineage differentiation were demonstrated. At the same time there is an increasing evidence of the MMSC plasticity due to a wide range of microenvironmental factors: extracellular matrix, cell-to-cell interactions, oxygen content, etc. In this paper, a comparative study of direct cell-to-cell and paracrine effects of MMSCs on human PHA-activated peripheral blood mononuclear cells (MNCs) in the standard (20%) and reduced to 5% O2 concentration in the culture medium was conducted. It is shown that after coculture with MMSCs the proliferative activity of PHA-MNCs, the share of HLA-DR(+) -T cells and IL-6, -8 and TNF-alpha concentrations were reduced, but IL-10 and IFN-gamma were increased in the medium. Potentiating effect on the MMSC immunomodulating properties was noted at low oxygen, which is of great importance for increasing the efficiency of immunosuppression.

Transgenic tobacco plants expressing the AINTEGUMENTA gene of rape under control of the 35S promoter and the promoter of dahlia mosaic virus were obtained. The transgenic plants were characterized by increase in the length of the leaves, flower sizes, stem height, and weight of seeds; at the same time, the degree of increase was greater in the case of use of the dahlia mosaic virus promoter as a regulator of transcription. Ectopic expression of the AINTEGUMENTA gene promoted prolongation of leaf growth, while sizes of epidermal cells of the leaves remained unchanged.

The long-term results of implant retained restorations with casted and milled frames were compared in clinical and experimental settings. Electrochemical features of milled and casted titanium by contact with titanium implant were assessed. The biocompatibility of milled and casted titanium was studied in mesenchymal stem cells culture. Cross sections were used to assess the marginal fit precision of milled and casted frames.

Mesenchymal stem cells (MSCs) can be isolated from many adult tissue sources. These cells are a valuable substrate in cell therapy for many diseases and injuries. Different types of MSCs vary in plasticity. We performed a comparative study of the neurogenic potential of three types of human MSCs derived from bone marrow (BMSCs), subcutaneous adipose tissue (ADSCs) and endometrium (isolated from the menstrual blood) (eMSCs). It was shown that all three types of MSC cultures demonstrate multipotent plasticity and predisposition to neurogenesis, based on the expression of pluripotency markers SSEA-4 and neuronal precursors' markers nestin and beta-III-tubulin. Further analysis revealed the transcription of the neuronal marker MAP2 and neurotrophin-3 in undifferentiated BMSCs and ADSCs. Additionally, a significant basal level of synthesis of brain-derived neurotrophic factor (BDNF) in eMSC culture was also observed. Stimulation of neural induction with such agents as 5-azacytidine, recombinant human basic fibroblast growth factor (bFGF), recombinant human epidermal growth factor (EGF), a recombinant human fibroblast growth factor 8 (FGF8), morphogen SHH (sonic hedgehog), retinoic acid (RA) and isobutyl-methyl-xanthine (IBMX), showed further differences in the neurogenic potential of the MSCs. The components of the extracellular matrix, such as Matrigel and laminin, were also the important inducers of differentiation. The most effective neural induction in BMSCs proceeded without the RA participation while the cells pretreated with 5-azacytidine. In contrary, in the case of eMSCs RA was a necessary agent of neural differentiation as it stimulated the transcription of neurotrophin-4 and the elevation of secretion level of BDNF. The use of laminin as the substrate in eMSCs appeared to be critical, though an incubation of the cells with 5-azacytidine was optional. As far as ADSCs, RA in combination with 5-azacytidine caused the elevation of expression of MAP2, but reduced the secretion of BDNF. Thus, the effect of RA on neural differentiation of ADSCs in ambiguous and, together with the study of its signaling pathways in the MSCs, requires further research. The therapeutic effect of transplanted MSCs is commonly explained by their paracrine activity. The high basal level of BDNF synthesis in the eMSCs, along with their high proliferative rate, non-invasive extraction and neural predisposition, is a powerful argument for the use of the intact eMSCs as a substrate in cell therapy to repair nerve tissue.

Development of antitumor preparations with low toxicity and high selectivity of action is one of the top priorities of cancer gene therapy. Mesenchymal stem cells possess natural tropism towards tumors, a property that makes possible their use as a vehicle for targeted delivery of therapeutic genes into tumors of various etiologies. At present, genes encoding enzymes (cytosine deaminase, thymidine kinase, carboxyl esterase), cytokines (IL-2, IL-4, IL-12, IFN-beta) and apoptosis inducing factors (TRAIL) are used as therapeutic genes. Mesenchymal stem cells, as demonstrated using experimental models of tumors of various etiologies as well as animals with metastases in brain and lungs, are able to successfully deliver therapeutic genes into tumors and produce significant antitumor effect. However, to effectively use this therapeutic strategy in clinic, one still has to solve a number of technical problems.

The review summarizes the results of studying the space and simulated microgravity effects on cell-to-cell interactions in three models: 1) interaction of a human lymphocytes culture with a subinoculated suspension culture of tumor myeloblasts K-562; 2) formation of embryoid bodies and differentiation of mice embryonic stem cells (ESCs); 3) gene differentiation and expression in multipotent mesenchymal cells (MCSs) obtained from the human marrow. It was shown that microgravity modifies the cell-to-cell interactions without cell contact inhibition; however, micro-g causes reversible changes in expression of genes responsible for regulation of the cytoskeleton, focal adhesion proteins, and some cytokines. Prolonged exposure of progenitor cells in simulated microgravity inhibits the differentiation processes of and reprofiles significantly expression of the genes that control various cell activities, including cell-to-cell interactions.

The authors review the findings of researches into the effects of low-dose ionizing irradiation on diverse biological objects (embryonic Japanese quails, Aspergillus niger, Spirostomum ambiguum Ehrbg., mesenchymal stem cells from mouse marrow, dry higher plants seeds, blood lymphocytes from pilots and cosmonauts). Model experiments with chronic exposure to ionizing radiation doses comparable with the measurements inside orbital vehicles and estimations for trips through the interplanetary space resulted in morphological disorders (embryonic Japanese quails, Aspergillus niger), radiation hormesis (Aspergillus niger, MSCs from mouse marrow), increase in the seed germination rate, inhibition of Spirostomum spontaneous activity, DNA damages, chromosomal aberrations, and increase of the blood lymphocytes reactivity to additional radiation loading. These facts give grounds to assume that the crucial factor in the radiation outcomes is changes in liquid medium. In other words, during extended orbiting within the magnetosphere region and interplanetary missions ionizing radiation affects primarily liquids of organism and, secondarily, its morphofunctional structures.

Coronary heart disease (CHD) is the most common cause of human mortality. Despite of recent advances in the management of CHD (drug treatment, coronary angioplasty and stenting, coronary artery bypass surgery) prognostic estimation of this kind of mortality threatens to increase to the year 2030. Major cause of adversity of CHD is decrease in myocardial contractility which leads to heart failure (HF). HF occurs as a result of myocardial cell ischemic injury or infarction. There is general assumption that recovery of myocardial contractility after tissue injury is not available. This dogma has been changed for the last decade with the introduction of stem cell (SC) therapy in cardiology. Research in this detection (nowadays the phase I-II of research is going on) proved SC therapy safety for human body (no risk of oncogenesis, heart attack or ventricular tachycardia, there is no heart remodeling and no need of coronary revascularization) and efficacy in myocardial contractility improvement (increase of left ventricular ejection fraction). Such positive results were obtained with the use of high dose SC therapy (10 8 cell) and its application the first week of acute myocardial infarction.

This article describes the main features of plant stem cells and summarizes the results of studies of the genetic control of stem cell maintenance in the apical meristem of the shoot. It is demonstrated that the WUS-CLV gene system plays a key role in the maintenance of shoot apical stem cells and the formation of adventitious buds and somatic embryos. Unconventional concepts of plant stem cells are considered.