Fetal liver stroma consists of different cell populations that are studied insufficiently. We have found skeletal muscle precursors that express MyoD in liver of 17 day and 20 day rat fetuses. Spontaneous myotube formation was observed in primary cultures of liver cells of 15, 17 and 20 day fetuses. Estimating antigenic profiles of these myogenic elements by immunocytochemistry and PCR methods unambiguously indicated their skeletal muscle nature. Comparative study of major myogenic gene expression demonstrated dependence of the myogenic potencies of liver cells on both the stage of fetal development and the duration of cell cultivation. It was shown that fetal liver MSCs were capable of myotube formation in the induction medium with 5-azacitidin. The results of our study, thereby, indicate that 15-20 day prenatal rat liver contains pre-existing skeletal muscle precursors expressing MyoD and, probably, inducible muscle precursors.

Fetal liver during period of its hematopoietic activity contains mesenchymal stromal cells (MSC) that are known to play a major role in establishing hematopoietic microenvironment. These cells are capable of clonal growing and multilineage differentiation, but only limited data exist about changes in their properties during prenatal development. We compared cloning efficiency of MSC from liver of 14, 16 and 20 day rat fetuses and evaluated their potentials to in vitro osteo- and adipogenesis and in vivo chondrogenesis after whole organ ectopic transplantation. Content of clonogenic MSC in suspension of liver cells was maximal in 16 day fetuses and to a lesser extent in 20 day ones. MSC derived from 16 day fetuses demonstrated maximal potential to estimated lineages. Osteogenic potential of MSC from 14 day fetuses was comparable to whereas their adipogenic and chondrogenic abilities were inferior to that from 16 day fetuses. Cells from 20 day fetuses had only weak adipogenic potency and failed to differentiate into osteogenic of chondrogenic pathways. The results indicate that both number and differentiation potential of MSC in developing rat liver correlate with dynamics of hematopoiesis in this organ. Detected changes may be ascribed to the decline of hematopoiesis in liver and acquisition its definitive functions.

Recent clinical and experimental researches on application of mesenchymal stem cells (MSC) in dentistry and maxillofacial surgery showed the efficiency of cellular technologies for acceleration of tissue regeneration and implants integration. However use of MSC solely and in combination with other substances has its advantages and disadvantages. There is lack of scientific data on contraindications and complications of cellular therapy whereas the analysis of failures of MSC application will allow accurately define indications and raise the efficiency of cellular technologies. There is a strong need for further clinical and experimental studies on MSC application for bone tissue regeneration.

We examined 41 patients with ischemic heart disease (n=26) and dilated cardiomyopathy (DCM) (n=15). Control group comprised 15 practically healthy subjects. We found no substantial differences in the presence of CD34+CD133- and CD34+CD133-VEGFR-2+ cells in peripheral blood of patients with chronic heart failure (CHF) but noted lowering of level of CD34-CD133+VEGFR-2+ cells mainly in DCM group. Most significant factors determining lowering of number of circulating endothelial precursor cells (EPC) were age, level of low density lipoprotein cholesterol, and intima media thickness of common carotid arteries. We found lowering of colony forming ability of EPC in patients with CHF first of all in the group of patients with DCM. Abnormality of qualitative and quantitative composition of EPC can be considered as one of risk factors of endothelial dysfunction, pathological remodeling of cardiovascular system and CHF progression.

One of the main criteria of pluripotency is ability of cell lines to differentiate into the germ line. Pluripotent stem cell lines in ground state of pluripotency differ from the lines in primed state by their ability to give rise to the mature gametes. To understand molecular mechanisms involved in regulation of different states of pluripotency we investigated the expression patterns of germ line specific genes in different type pluripotent stem cells and mouse and human embryonic teratocarcinoma cells. We found that pluripotent stem cells in vitro, in blastocyst and gonocytes at stage E13.5 had similar expression patterns in contrast to the epiblast cells at stage E6.5. Quantitative real time PCR analysis showed that Vasa/Ddx4 expression in mouse and human embryonic stem cells was significantly lower than in blastocyst and gonocytes. Moreover, Vasa/Ddx4 and E_ras expression was significantly higher in mouse embryonic stem cells than in human embryonic stem cells. Our analysis of germ line specific gene expression in differentiating mouse embryonic stem and embryonic germ as well as in mouse embryonic teratocarcinoma cells maintained under conditions promoting cell reprogramming from primed to ground state of pluripotency (2i + LIF) revealed that only pluripotent stem cells are able to regulate the expression level of Oct4 and Vasa/Ddx4 and restore initial ground state, while in embryonic teratocarcinoma cells the expression level of these genes remained unchanged. We suggest that expression patterns of germ lines specific genes, in particular of Vasa/Ddx4, can underlie the regulation of ground and primed states of pluripotency. [corrected].

We have performed structural and functional studies of the hemotropic activity for a number of novel 2,5-diketopiperazine peptidomimetic derivatives. We employed a mouse model of hemopoietic stem cells cloning in the spleen of lethally irradiated animals. Biologic activity of synthetic products was studied in two experimental models: 1) in vitro irradiated bone marrow SFU-S was used for studying the radio modifying activity; 2) the biological effect of peptidomimetics on the intact non-irradiated bone marrow was evaluated in vivo. Various ways of administration of the peptidomimetics studied were used in the in vivo experiments: intravenous, intraperitoneal or subcutaneous injections and oral administration in the dose range of 10-10000 microg/kg. As a result of our work, we have discovered 2,5-diketopiperazine peptidomimetic derivatives with the dual activity: stimulation of intact committed SFU-S and radiomodifying activity.

The aim of the study was to assess long-term results of high-dose immunosuppressive therapy with autoimplantation of hemopoietic stem cells in patients with severe systemic lupus erythematosus (SLE) resistant to standard immunosuppressive therapy and compare them with the outcome of the two modalities. The study and control groups comprised 15 women each aged 18-55 and 20-55 years respectively. The results were estimated 1 months after the onset of therapy and during the 45 +/- 10.4 (study) and 30 +/- 7.6 (control) month follow-up. Combined treatment resulted in complete remission (SLEDAI below 3) in 6 (40%) and reduced SLE activity in 6 (40%) patients. The effect was absent in 1 (7%) patient, 2 others died. Remission and reduced SLE activity occurred in 1 (7%) and 1 (7%) patients of the control group respectively, 13 (87%) failed to benefit from therapy, and 1 (7%) died. Seven (47%) patients given combined treatment suffered recurrence of SLE, 3 (20%) had complete or partial remission, and 3 died during the long-term follow-up. Five-year survival rate was 80%. None of the patients in the control group showed remission in the late posttreatment period, SLE activity remained unaltered in 8 and progressed in 4; two patients died. Five-year survival rate was 70%. It is concluded that high-dose immunosuppressive therapy with autoimplantation of hemopoietic stem cells is an efficacious tool for the treatment of lupus erythematosus resistant to standard therapy and has advantages over the latter.

Immunocytochemical method was used to determine the distribution of neurons expressing heme oxygenase-2 (HO-2-positive neurons) in the nuclei of various parts of the brainstem of 16 male Wistar rats. The sizes of neurons and the optical density of the product of histochemical reaction in their cytoplasm were determined in the nuclei studied. HO-2-positive neurons, differing in shape, size and numbers, were identified in the nuclei of the medulla oblongata, pons and midbrain. HO-2-positive cells were found 3-5 times more frequently in the sensory nuclei as compared to the motor ones. At the same time, relatively large number of nuclei was detected, which contained either no or a few HO-2-positive neurons.

The effect of dicarbamine on hemopoiesis in experimental post-irradiation bone-marrow syndrome was studied. The myeloprotective activity of the drug was established. It manifested in the protection of hematopoietic progenitor cells and stimulation of cell proliferation and differentiation in the bone marrow.

Cytomegalovirus (CMV) is one of the common pathogens of opportunistic infections in patients with inflammatory bowel diseases. When the patients are treated with immunosuppressants that make them more susceptible to CMV, the course of ulcerative colitis (UC) becomes considerably worse. Antiviral therapy sometimes can reduce the risk of complications and the rate of colectomies. At the same time, antiviral therapy is not mandatory for all UC patients with CMV infection, as shown by the results of numerous investigations. One of the properties of mesenchymal stromal cells (MSC) is to suppress the body's immune reactions to allostimulation, rather than to infection invasion. In vivo and in vitro studies have demonstrated that MSCs have antiviral and antimicrobial activities. The described clinical case shows that clinical improvement occurred and a drastic activation of proliferative processes in the colonic mucosa was detected in the patient with UC after MSC transplantation. Administration of cultured MSCs also promoted the elimination of CMV without antiviral therapy and the overcoming of hormone dependence/ resistance in the patient with UC.

Tissue renewal is the known phenomenon, when the progeny of resident or circulated stem cells (SC) replaces the vanishing cells. The delivery of stem cells via circulation should result in stem cell homing and differentiation into wide variety of tissues and gives promise as therapy for many diseases of tissue failure including aging itself. To test this hypothesis, we created chimeric mice C57BL/6 by bone marrow (BM) transplantation from young 1.5 months old donors to 21.5-months old recipient mice of the same strain C57BL/6. We applied here the recently published new transplantation technique, which allows to get high scores of chimerism due to very high amount of transplanted cells (1.5 x 10(8) per mouse or 25% of its total BM count). In the earlier works only 1% of total BM count (about 5 x 10(6) cells per mouse) was usually transplanted to lethally irradiated mice, what excluded the possibility to apply this method for life extension. As a result of the modified technique implementation, the mean post-transplantation life (starting the 21.5 months old) of treated mice was 4.9 months versus 3.4 months for untreated mice. The difference in 1.5 months counts for 44% extension of mean post-transplantation life.

The expression of matrix metalloproteinase 2 and 9 in thymus and pineal gland has been verified. These data demonstrate single mechanism of remodelling extracellular matrix in thymus and pineal gland at aging.

The aim of our study was to analyze the expression of one of the markers of progenitor cell of different cell types - CD 117 (C-kit) - in human pancreas during prenatal development. The pancreas of human embryos and fetuses at 4-28 weeks of gestation as well as of infants aged up to 2nd postnatal month, was studied. In histological sections, the immunocytochemical reactions were performed with the antibodies against C-kit, insulin and glucagon. In situ hybridization was used for detection of proinsulin mRNA. First cells expressing C-kit were found in human pancreas at 8.5 weeks of gestation among ductal epithelial cells. At 11.5 weeks of gestation these cells were found to segregate from the ductal epithelium and start to form islets. From 8.5 weeks of gestation C-kit positive cells started to express glucagon and proinsulin mRNA, and after 11.5 weeks they also expressed insulin. Islet C-kit positive cells coexpressing both glucagon and insulin, were also found after the birth. It may be concluded that C-kit positive endocrinocyte progenitor cells are common for pancreatic islet A- and B-cells and they are preserved in he islets after the birth.

The changes in the processes of differentiation, proliferation and apoptosis were studied in the culture of human cortical thymocytes after cell exposure to T-32 and T-38 bioregulator peptides. T-32 and T-38 peptides were shown to enhance the differentiation of immature cortical thymocytes (CD4+CD8+) into T-regulatory cells by increasing their proliferate activity and decreasing the level of apoptosis. Moreover, these peptides were found to stimulate the proliferative and antiapoptotic activity of mature T-regulatory (CD4+CD25+) cells.

Chronic liver disease (CLD) leads to disability annually hundreds of thousands of patients worldwide. Originating as a rule, at a young age (20-40 years), they are always significantly degrade the quality of life of patients, making them socially significant. Moreover, the conventional treatment (hepatoprotectors, antiviral drugs, corticosteroids, immunosuppressive medication) not always lead to achieving the desired effect, and therefore is constantly searching for alternative treatments. Cell therapy with embryonic fetal, mononuclear, mesenchymal stromal cells is the most advanced front of modern biotechnology and medicine. Using the SC with the purpose of treatment in chronic liver diseases is the possibility of disturbed regulation of cell-cell interactions in the liver, the impact on the mechanisms of cell death (necrosis - apoptosis) and fibrogenesis, which makes this method the most relevant and promising in hepatology. The article presents an analysis of the results of studies conducted in the field of stem cell technologies by leading domestic and foreign scholars in the treatment of liver diseases. Were studied questions of transdifferentiation, the mechanisms of stem cells in hepatology, as well as the possible risks of this therapy (pro-oncogene action, increased fibrosis). Also was presented our own experience of applying cellular technology in experimental models of acute toxic hepatitis in animals.

The analysis of possible morphogenesis of the different structures in human yolk sac tumor has been considered. The author has supposed that features of blood vessel microarchitecture formation and perpetual differentiation of tumor cells or theirs functional modification play a crucial role in the morphogenesis of YST. The immunohistochemical investigation of some stem cells markers has showed the necessity of accounting of their distribution pattern in various cellular structures for the differential diagnosis of morphogenetical steps of YST. The growth of tumor cells differentiation rate correlates with increasing of stem cells markers expression as well c-kit > OCT4 > CD30 > PLAP.

Regeneration of the cartilage is one of the difficult and uncertain solved problems of reconstructive surgery. Lot of successfully experiments was done about regeneration of cartilage defects with ADAS cells. Use of stem cells promise new decisons in this direction at the near future. Little information about ADAS cells and their use in regeneration of cartilage defects was revealed.

Dynamics of VEGF gene expression in transfected multipotent stromal cells from adipose tissue was examined using electroporation and lipofection. Differences in the potency and dynamics of plasmid elimination (up to day 9) between cell cultures were observed. All cultures were divided into fast and slow plasmid-eliminating ones. Interculture differences in VEGF expression were detected. The possibility of a 5-6-fold increase of VEGF expression was shown. There were no differences in transfection potency, plasmid elimination dynamics, and VEGF expression after transfection by both nonviral methods.