[Characteristics of migration of adipose tissue derived mesenchymal stromal cells after co-cultivation with activated monocytes in vitro].

Mesenchymal stromal cells (MSC) are considered to be promising tool of regenerative medicine. Migration of MSC toward damaged inflammatory site is essential for physiological tissue reparation. Therefore we studied modifications of migratory features of adipose tissue derived MSC (AT-MSC) after co-cultivation with activated monocytes derived from THP-1 cell line. As a result, we have observed an increased migration rate of AT-MSC in vitro in the absence of chemoattractant gradient as well as toward the gradient of PDGF BB (platelet-derived growth factor BB), which is well known chemoattractant for the cells of mesenchymal origin. Furthermore, the rate of directional AT-MSC migration through fibronectin was also increased. We have established that signaling from PDGFRß which is activated through binding of integrin receptors with extracellular matrix may be possible way to stimulate cellular migration under simulated inflammatory conditions.

[Clinical characteristics of patients and number of stem cells in the myocardium of right atrial appendage in patients with ischemic heart disease].

In the last years stem cells (SC) have been identified in rodent and human hearts. These cells have ability to multilineage differentiation in vitro and in vivo and improve cardiac function. The development of new methods of isolation SC offers new approaches to cardiac regeneration. However, the question of how individual patient characteristics influence the number of SC remains unclear. In our study we aimed to define the correlation between patient characteristics and SC number. Our findings suggest that clinical characteristics and severity of the disease may affect the yield of SC in heart tissue. Our data contribute to the development of efficient methods for SC isolation for stem cell therapy.

[T-cadherin suppresses the cell proliferation of mouse melanoma B16F10 and tumor angiogenesis in the model of the chorioallantoic membrane].

The influence of T-cadherin on the pigmentation and proliferation of mouse melanoma B16F10 cells in vitro and on the growth and neovascularization of tumor cell masses formed by the B16F10 cells in a model of the chorioallantoic membrane of a chicken embryo is studied. It is found that the proliferative activity of the cells decreases in the cell culture of mouse melanoma upon the hyperexpression of T-cadherin in comparison with the cells in the control. It is shown in experiments in vitro that the B16F10 cells with the hyperexpression of T-cadherin are less adaptive to the chorioallantoic membrane than the control cells. In addition, it is found that the control cells of mouse melanoma form tumors with area more 0.1 mm2 more often than the cells with the hyperexpression of T-cadherin and the amount of the vessels growing to tumor cell masses formed by the cells with the hyperexpression of T-cadherin is significantly lower than the same index for the cells in the control. Thus, the hyperexpression of T-cadherin in the B16F10 cells suppresses the proliferation of these cells in vitro and the growth of the tumor masses formed by melanoma cells on the chorioallantoic membrane and their neovascularization in vivo are demonstrated.

[Mechanism of stimulation of angiogenesis in ischemic myocardium with the help of adipose tissue stromal cells].

Stromal cells from subcutaneous adipose tissue (adipose derived stromal cells - ASCs) are perspective for cell therapy of ischemic states because of ability to stimulate growth of vessels. For the elucidation of mechanisms of angiogenic action of ASCs we used the model of co-cultivation of ASCs with cells isolated from postnatal hearts (fraction of cardiomyocutes - CMC). CMC fraction contained mature cardiomyocytes, endothelial and progenitor cells. On the 2-nd day spontaneously beating colonies of CMC with growing from them CD31-positive capillary-like structures were formed in CMC culture. Observed structures were unstable and came apart after 5 days of cultivation. At co-cultivation of CMC with ASCs formation of stable ramified CD31-positive structures was observed. Using the method of co-cultivation of CMC with mitomycin C treated ASCs and the method of immune magnetic depletion for removal of epithelial cells from the CMC fraction we found that ASCs stimulates formation of capillary like structure at the account of secretion of angiogenic factors, stabilization of forming CD31-positive structures at the account of intercellular contacts and stimulation of endothelial differentiation of progenitor cells present in CMC fraction.

[Left ventricular heart aneurism--a new source of resident cardiac stem cells].

In the past few years it has been established that the heart contains a reservoir of stem and progenitor cells that have the ability to differentiate in vitro and in vivo toward vascular and cardiac lineages and that show cardiac regeneration potential in vivo following injection into the infracted myocardium. The aim of the present study was to characterize cardiac stem cells in the tissue of chronic left ventricular aneurism. It was shown that human c-kit positive cells were scattered in fibrous, muscle and adipose parts of aneurism tissue. C-kit positive cells localized mainly in fibrous tissue nearby large vessels, however, c-kit positive cells did not express endothelial, smooth muscle or cardiomyocyte cell markers. Co-localization experiments demonstrated that all c-kit positive cells were of non-hematopoietic origin, since they did not express markers such as CD34 and CD45. Majority of c-kit positive cells expressed MDR1, but showed no proliferation activity (Ki67). It thus appears that aneurism tissue could be an alternative source of autologous cardiac stem cells. However, their regeneration capacity should be further explored.

[Centrosome and Golgi complex during differentiation of hepatocytes in early postnatal development of mice].

The structure and functional activity of the centrosome was analyzed in hepatocytes of 5-day old mice, as well as the lengths of Golgi complex cistemae. In the early postnatal development of mice, the liver was represented by two types of hepatocytes: in the first type hepatocytes, the centrosome was active as an organizing center of microtubules, while in the second type hepatocytes, it was inactive. It was proposed that during ontogenesis the centrosome is inactivated as an organizing center of microtubules and activated as an organizing center of intermediate filaments characteristic for differentiated hepatocytes of adult liver. Morphometry of the Golgi complex has shown that Golgi cisternae in the cell center area of early postnatal hepatocytes were longer than in the adult hepatocytes and comparable to those in G1-phase hepatocytes of regenerating liver. The possibility of relations between the differences in the Golgi complex morphology and ontogenetic changes in the functional activity of centrosomes is discussed.