Comparative characteristics of platelet lysates from different donors.

We studied the effect of platelet lysates from different donors on fibroblast growth in culture. In most samples (40 of 50), the growth-stimulating characteristics were greater than in 10% FCS, but every ninth sample exhibited low mitogenic activity. A weak dependence between platelet concentration and total protein content was noted, but no correlation was found between these parameters and fibroblast growth in culture.

Effect of transplantation of mesenchymal stem cells on neuronal survival and formation of a glial scar in the brain of rats with severe traumatic brain injury.

We studied the effect of various methods of transplantation of mesenchymal stem cells on neuronal survival in rat brain 1 and 6 weeks after severe traumatic brain injury. It was found that intracerebral and systemic transplantation of mesenchymal stem cells improves neuronal survival in the piriform cortex of the contralateral hemisphere without affecting neuronal survival in the marginal zone of the traumatic cavity and amygdaloid nuclei. Intracerebral transplantation of mesenchymal stem cells increases the content of the astroglial component of the scar in the borderline zone of the traumatic cavity.

Alterations of cytological and karyological profile of human mesenchymal stem cells during in vitro culturing.

Transplantation of human bone marrow mesenchymal stem cells is considered as a promising therapeutic approach to the therapy of many diseases. However, the problem of possible alterations of the properties of mesenchymal stem cells during their expansion in in vitro cultures before transplantation is not solved. In our study, one of two hundred examined cultures of mesenchymal stem cell cultures derived from donors without bone marrow pathologies and developed under standard culturing conditions demonstrated spontaneous disturbances in morphology, proliferation, and karyotype at early passages. The cells of this abnormal culture retained immunophenotype characteristic of normal mesenchymal stem cells, but some of them (15-25%) had numerous numerical and structural chromosome aberrations.

Distribution of mesenchymal stem cells in the area of tissue inflammation after transplantation of the cell material via different routes.

In experiments on male Wistar-Kyoto rats we studied the distribution of mesenchymal stem cells in intact body and in the presence of a focus of acute tissue inflammation. In healthy animals mesenchymal stem cells were transplanted intravenously. In the second case we used various routes of transplantation of mesenchymal stem cells: intravenous, into tissue adjacent to the inflammation focus, and into intact lobe of the damaged organ (prostate gland). Three weeks after transplantation, mesenchymal stem cells labeled with a fluorescent dye were detected in the bone marrow and intestine of intact animals. In case of inflammation focus, mesenchymal stem cells after transplantation migrated into the bone marrow, intestine, and prostate gland. After injection into the adjacent zone, these cells formed a compact agglomerate at the site of injection. After transplantation into the intact lobe of the prostate gland the cells migrated towards the inflammation focus. Thus, transplantation of mesenchymal stem cells into the venous blood is less traumatic and led to more uniform distribution of cells in the damaged tissue.

In vitro and in vivo differentiation of mesenchymal stem cells in the cardiomyocyte direction.

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.

Effect of mesenchymal stem cell transplantation on cognitive functions in rats with ischemic stroke.

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.

Effect of mesenchymal stem cells on rejection of xenogenic bone transplant.

We studied the effects of mesenchymal stem cells on rejection of xenogenic bone transplant. Experiments were carried out on Wistar-Kyoto rats transplanted chicken demineralized bone matrix populated or not populated with mesenchymal stem cells to the site of parietal bone defect. Histological analysis showed complete resorption of the xenogenic transplant not populated with mesenchymal stem cells by day 119. In experimental animals chicken matrix without signs of tissue inflammation was in fact completely retained over the entire period of observation. Numerous new vessels, mineralization fields, and areas of bone tissue formation were seen in the transplant.