The relationships between embryonic stem and cambial cells in the ontogeny were evaluated on the basis of our data on organ embryogenesis and in vivo implantation of epithelial tissues and published data. We demonstrated the role of recipient tissues in the implantation process. Aseptic inflammation developing in response to the implant activates proliferation of the adjacent donor tissues. Proliferation and differentiation of the implanted donor tissues correspond to inflammation phases in the focus of implantation, are regulated by factors of the recipient organism, and are histogenetically determined.

We studied the interaction between different categories of hemopoietic precursors with parathyroid hormone-activated stromal microenvironment. Improved survival of early precursors capable long-term hemopoiesis maintenance and increased number of later short-term repopulating precursors was demonstrated on the model of co-culturing of human bone marrow cells on a layer of adherent cells of long-term bone marrow cultures treated with parathyroid hormone. These changes correlate with increased expression of genes involved in the maintenance of the hemopoietic stem cells in the sublayer activated by parathyroid hormone. Simultaneously, the expression of some stromal differentiation genes, adhesion molecules for hemopoietic stem cells, and growth factors increased in adherent cell layers treated with parathyroid hormone. These findings attest to activating effect of parathyroid hormone on cells forming the niches for both early and later hemopoietic precursors, and hence parathyroid hormone can be used as a potential agent promoting expansion of early hemopoietic stem cells ex vivo.

Comparative analysis of the expression of some surface markers of human bone marrow mesenchymal stem cells, umbilical fibroblast-like cells, and skin fibroblasts was carried out by the flow cytofluorometry method. Mesenchymal stem cells and umbilical fibroblast-like cells were similar by the levels of expression of the main histocompatibility complex antigens, adhesion molecules, and some growth factor receptors. The profile of skin fibroblast surface antigens was characterized by higher expression of the markers typical of differentiated cells. The results prove the possibility of using umbilical fibroblast-like cells as an alternative source of mesenchymal stem cells for cell replacement therapy.

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.

The effect of intravenous transplantation of mesenchymal stem cells on the recovery of cognitive functions was studied in Wistar-Kyoto rats after brain stroke induced by occlusion of the middle cerebral artery in the left hemisphere. Analysis 2 and 5 weeks after stroke showed that transplantation of mesenchymal stem cells 3 days after middle cerebral artery occlusion reduced the area of cerebral injury, preserved cognitive functions, and decreased mortality in experimental animals.

The possibility of mesenchymal stem cell differentiation in the cardiomyocyte direction was studied on Wistar-Kyoto rats with myocardial infarction induced by ligation of the left coronary artery. In vitro treatment of mesenchymal stem cells with 5-azacitidine led to spontaneous contractions of about 15% cells in culture. Analysis of the expression of matrix RNA showed expression of fetal and functional markers of the myocardium in this cell culture. In vivo on day 21 after myocardial infarction and intravenous transplantation of mesenchymal stem cells into the periinfarction area, myocardial cells carrying donor label were detected. Immunohistochemical analysis showed that these cells were cardiomyocytes integrated into the myocardium. These cells can be a result of differentiation of transplanted mesenchymal stem cells or fusion of endogenous cardiomyocytes with exogenous mesenchymal stem cells.

In recent decades, a wide spectrum of fetal and embryonic stem and progenitor cells were used for cell therapy of diseases of the central nervous system, but the olfactory glial ensheathing cells exhibited certain advantages due to their biological properties and capacity to stimulate regeneratory processes in spinal injury. The therapeutic effect of a heterogeneous complex of olfactory epithelial cells is more pronounced; apart from glial ensheathing cells, this complex includes fibroblasts, Schwann cells, stem and progenitor cells of this structure. The use of minimally invasive methods for isolation of human olfactory epithelial tissue is important for clinical practice, because they provide cells for autologous transplantation and rule out graft rejection immune reaction and the risk of transmission viral infection and transfer of genetic defects, which can be associated with allotransplantation.

In this work the attempt to estimate a nitric oxide (NO*) role in regulation of the number of pool haemopoietic stem cells at the irradiated mice was made. With this purpose the number of new compounds from dihydrothiazine-thiazoline line was synthesized, their NO-inhibiting activity was investigated in vivo by the method of ESR-spectroscopy of spin trap and their influence on an output endogenous spleen colonies (CFU-S-8) after the total sublethal y-irradiation of mice in a doze of 6 Gy was also investigated. Was shown, that the tested compounds reduced the contents of NO* in a liver tissue of mice which have received an injection of nitric oxide synthesis inductor - lipopolysaccharide, and also increased an output CFU-S-8 forming endogenous colonies in the spleen of the irradiated mice. Received data testify to perceptivity of search radioprotective agents among NO* synthesis inhibitors.

The intensity of regeneration of crossed gastrocnemius muscle was evaluated in two groups of mdx mice of different age 2 weeks after implantation of crushed muscle tissue from newborn rats into the wound defect area. The effect of xenoplasty manifested in increased weight of the damaged muscle. The effect was observed in mice aging 12-16 weeks but not in those aged 40-48-weeks. Structural changes in the skeletal muscle tissue intrinsic of mdx mice and augmenting with age were detected in intact mice before the experiment. Activity of muscle fiber regeneration in intact and injured muscle of 40-48-week-old mice was significantly lower than in 12-16-week-old ones. Myoblasts of the xenogenic transplant retained viability in recipient muscles for at least 2 weeks. posttraumatic regeneration was stimulated in only 12-16-week animals. Xenoplasty was ineffective in older animals and even somewhat enhanced the destructive processes in the muscle. It seems that age-specific regeneration activity of the recipient skeletal muscle tissue should be taken into consideration in the development of effective strategy of cell therapy for progressive muscular dystrophy.

The structure and cell composition of spheres obtained by culturing human fetal retinal cells after 15, 18, 22-23, and 24 weeks of gestation were studied. The cells were cultured as neurospheres: in serum-free medium with growth factors, in which they formed floating spheres. Immunocytochemical analysis showed that cell proliferation in the spheres decreased with increasing fetal age. Stem/progenitor cells, neuroblasts, and photoreceptors were detected in the spheres. Glial cells were detected only in spheres originating from 22- and 24-week fetuses. All spheres, irrespective of age and duration of culturing, consisted of numerous cell rosettes, each histotypically similar to the neuroblastic layer of the developing retina.

Inoculation of cells derived from the aorta of Wistar rats on devitalized porcine aortic walls 2-4-fold reduced their calcinosis after subcutaneous implantation to Wistar rats. Inoculation of Wistar rat bone marrow mesenchymal cells selected by adhesion activity did not reduce tissue calcinosis. The results indicate good prospects of repopulation of devitalized heart valve and vessel transplants by recipient vascular cells for reducing transplant calcinosis and improvement of their biocompatibility.

Effects of systemic transplantation of mesenchymal stem cells obtained by culturing of autologous bone marrow on proliferative activity of cells and functional morphology of neurons after diffuse brain injury were studied in Wistar rats. Comparative analysis of the results indicated that systemic injection of mesenchymal stem cells in a syngeneic organism produced proliferotropic, angiogenic, and, presumably, neurotrophic effects. The therapeutic effect visually manifested on day 2 after intravenous injection of mesenchymal stem cells during the early period of reparative regeneration of ischemic cell and tissue structures of the brain. The neuroprotective effect of mesenchymal stem cells was more pronounced against the background of basic therapy.

The development of autoimmune disease in Fas-deficient MRLMpJ/lpr mice is associated with a relative decrease in the content of bone marrow CD34+ cells, which can attest to intensification of migration of early hemopoietic precursors from the bone marrow. The intensity of CD34+ apoptosis is high in young healthy MRLMpJ/lpr mice in comparison with the control, but decreases during the development of autoimmune disease. Proliferative activity of CD34+ cell population surpassed the control in all mouse groups, except AID2. The detected shifts in quantitative and qualitative parameters of CD34+ cells attest to an important role of stem hemopoietic precursors in the formation of autoimmune disease in MRLMpJ/lpr mice.

Cultured pure population of Ito cells isolated from adult rat liver expressed epithelial markers cytokeratin-8, alpha-fetoprotein, and gamma-glutamyl transpeptidase after forming a dense monolayer. Mesenchymal-epithelial transformation of these cells is possible, which suggests them as candidates of hepatic stem cells.

We demonstrated that liquor from adult humans can maintain proliferative activity of cells of immature nervous tissue in vitro. The paper presents the results of a retrospective clinical study of the efficiency of cell therapy in the treatment of II-III degree comatose patients with severe brain injury. Cell suspension consisting of cells derived from immature nervous and hemopoietic tissues was injected into the recipient subarachnoidal space through a cerebrospinal puncture. The mortality in the study group was 8% vs. 56% in the control group. The 1.5-year follow-up demonstrated significantly better quality of life in patients receiving cell therapy in comparison with patients of the control group. Cell therapy proved to be ineffective for patients in a comatose state caused by hypoxic encephalopathy. The study demonstrated the efficiency of cell therapy in patients with severe brain injury during the acute period of the disease.

A combined graft consisting of a free full-thickness skin flap and cultured autologous fibroblast-like bone marrow mesenchymal stem cells was effectively implanted and healed on the facial soft tissue defect after removal of a pathological vascular conglomeration in a female patient with congenital arteriovenous macrofistulous dysplasia. In order to reduce bloodflow intensity and arteriovenous shunting, repeated endovascular occlusion and transcutaneous ligature of regional vessels from the carotid artery basin feeding the pathological zone was carried out followed by resection of this tumor-like vascular formation.

We propose a method of creation of a 3D matrix consisting of native collagen fibers and natural polysaccharide chitosan. The collagen-chitosan hydrogels maintain viability and prolipherative activity of embryonic stem cells obtained from internal cells of mouse blastocyst. The proposed system forming hydrogels in situ can be used in cell therapy for immobilization and targeted delivery of stem cells.

We studied the state of different pools of mesenchymal precursor cells in the bone marrow, peripheral blood, and wound surface after modeling of tissue damage by skin flap removal. The participation of regional and circulating stromal precursors in the healing of skin defect and the absence of compensatory reaction of the regeneratory process deep reserve, mesenchymal stem cells of the bone marrow, was demonstrated.

We compared the effects of transplantation of fetal fibroblasts and fibroblast-like mesenchymal stem cells of the bone marrow on healing of deep burn wound in rats. It was found that transplantation of fetal fibroblasts and fibroblast-like mesenchymal stem cells on the burn surface reduces cell infiltration, promotes the formation of vessels and granulation tissue, which creates conditions for more rapid healing of the burn wounds.

We studied the state of pools of mesenchymal precursor cells of different maturity in the bone marrow and peripheral blood and the dynamics of the content of regional parenchymal stem cells and stromal precursors in the pancreas during experimental diabetes mellitus. Reduced content of organ-specific stem cells and increased content of stromal precursors in the pancreas in the absence of compensatory reaction of deep reserve mechanisms, mesenchymal bone marrow cells, were revealed.