Cardiovascular diseases, along with cancer, are the leading causes of death worldwide. Although modern pharmacological treatment of various cardiomyopathies can slow the development of myocardial dysfunction, they have limited effectiveness in patients with end-stage disease. Many researchers believe that heart transplantation is the only radical treatment in this case. However, the lack of donors and the high operation cost require careful selection of surgical candidates. With the introduction of molecular and cell biology into medical practice, today, stem cell therapy can become an alternative method of nonsurgical restoration of myocardial functions. The most studied and attractive is the use of mesenchymal stem cells (MSCs). MSCs differ from hematopoietic stem cells used as support for hematopoiesis in high-dose chemotherapy by the following features: pronounced trophic effect, immune tolerance, the ability to suppress alloreactivity and autoimmune disorders. An important stage in the implementation of cell therapy is the creation of a cell biobank of MSCs. In A.F.Tsyb Medical Radiological Research Center, this work has been carried out since1984. Asignificant number of experimental studies have been carried out, confirming the possibility of clinical implementation of this approach. A method for obtaining stable cultures of MSCs and cardiomyoblasts from bone marrow cells was developed and approvals were obtained. Experimental studies of cell therapy are also being conducted to overcome anthracycline-induced cardiotoxicity in cancer patients.This article is devoted to practical application of MSC-based therapy, in particular, in cancer patients with cardiotoxicity, as well as to the issues of creating a cell biobank for treatment with MSCs.

Experiments on F1(CBA×C57BL/6) mice with experimental metastatic melanoma B16 F10 showed that single intravenous injection of xenogeneic bone marrow mesenchymal stromal cells (BM-MSC) in a dose of 106 cells/mouse significantly increased 100-day survival rate of tumor-bearing animals. In contrast, administration of BM-MSC in a dose of 2×106 cells/ mouse reduced survival rates in comparison with the biocontrol (injection of B16 cells alone, 5×105 cells/mouse). This phenomenon can be related to in vivo participation of BM-MSC in reprogramming of resident tissue macrophages, including tumor microenvironment, towards pro- (M1) or anti-inflammatory (M2) phenotype. This is indirectly confirmed by the data on switching from activation to inhibition of ROS-producing activity of blood mononuclears and peritoneal macrophages in tumor-bearing mice in the test of luminol-dependent zymosaninduced chemiluminescence.

In vivo modifying effects of bone marrow mesenchymal stromal cells of humans and laboratory mice on ROS production by mouse blood mononuclears are studied by luminol-dependent zymosan-induced chemiluminescence after syngeneic and xenogeneic transplantation into systemic blood flow. The chemiluminescent activity of mouse blood mononuclears has increased early (1 day) after syngeneic (mouse mesenchymal stromal cells) and xenogeneic (human mesenchymal stromal cells) transplantation. Later, 7-21 days after syngeneic and xenogeneic transplantation, the chemiluminescent activity of mouse mononuclears is suppressed. The probable mechanisms of involvement of the transplanted mesenchymal stromal cells in reprogramming of the blood mononuclear phagocytes from proinflammatory (M1) to anti-inflammatory (M2) phenotype under conditions of their in vivo interactions are discussed; a frequent manifestation of this reprogramming is transition of the phase of activation into inhibition of ROS-producing activity of macrophages.

We studied in vivo modifying effect of autotransfusion of human bone marrow mesenchymal stromal cells on ROS generation and production of cytokines (TNFα,TNFβ, IL-1α, IL-10, IFNγ, and GM-CSF) and PGE2 by mononuclear cells of patients (N=21) with chronic heart failure. These parameters were evaluated prior to (control) and after (immediately and on day 14) intravenous administration of stromal cells in doses of 100-200×106. Immediately after autotransfusion, significant increase of in vitro zymosan-induced chemiluminescence of blood mononuclear cells from 10 patients was observed. At later terms after autotransfusion (day 14), inhibition of chemiluminescent activity of blood mononuclear cells was revealed in 50% patients. We discuss possible mechanisms of involvement of transplanted autologous bone marrow mesenchymal stromal cells in reprogramming of blood mononuclear phagocytes from the pro- to anti-inflammatory phenotype under conditions of their in vivo interaction manifesting in transition from activation to inhibition of ROS-producing activity of macrophages and significant suppression of in vitro LPS-induced production of TNFα and GM-CSF by blood mononuclears against the background of significantly elevated TNFβ, IL-10, and IL-1α concentrations.

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.

We studied the effect of transplantation of human stem cells from various tissues on reparative processes in the brain of rats with closed craniocerebral injury. Combined treatment with standard drugs and systemic administration of xenogeneic stem cells had a neuroprotective effect. The morphology of neurons rapidly returned to normal after administration of fetal neural stem cells. Fetal mesenchymal stem cells produced a prolonged effect on proliferative activity of progenitor cells in the subventricular zone of neurogenesis. Adult mesenchymal stem cells had a strong effect on recovery of the vascular bed in ischemic regions.

The study undertaken 3 years ago examined the effect of systemic transplantation of autologous mesenchymal stem cells (MSC) in the complex therapy of 27 patients with pulmonary tuberculosis, including 15 patients with multidrug-resistant pulmonary tuberculosis and 12 with extensive drug resistance of Mycobacterium tuberculosis. All the patients were bacteria-discharging persons with disseminated destructive processes in lung tissue, most (n=17) of them had chronic fibrocavernous tuberculosis. In all the patients, previous long specific antituberculous treatment was ineffective or inadequately effective. After systemic MSC transplantation, 16 patients were followed up for 1.5-2 years or more and the remaining 11 patients for at least 6 months. After MSC administration, a positive clinical effect was observed in all 27 cases; bacterial discharge stopped in 20 patients after 3-4 months; resolution of sustained lung tissue cavities further occurred in 11 patients. At present, a persistent remission of a tuberculous process may be stated in 9 of the 16 patients in whom MSCs were transplanted 1.5-2 years, significant positive bacteriological and morphological changes are observed in 6 patients. Thus, inclusion of transplantation of the autologous MSCs propagated in the culture into a course of antituberculous therapy may be a promising procedure for enhancing the efficiency of therapy in patients with resistant forms of pulmonary tuberculosis.

Systemic transplantation of mesenchymal stem cells (MSC) is known to promote reparative process in a number of tissue damage as well as lung tissue one. It provided the basis for our study which was aimed to the effect of systemic transplantation of autologous MSC (intravenous transfusion) in complex therapy of patients with resistant pulmonary tuberculosis. Started three years ago, 27 tuberculous patients are being under our observation now; 15 patients were classified as having multidrug resistance, 12 cases as being X-drug resistant. Bacterioexcretion and substantial pulmonary cavitation were observed in every patient, most of them (n=17) having chronic tuberculosis of 13 months to 5 years duration, the rest 10 patients diagnosed 6 to 12 months before including them to the study. All these patients had previously been undertreated or unsuccessfully treated, with one patient having one lung removed. Undergone systemic transplantation of 150-200 million of cultured MSCs derived from autlogous bone marrow the patients continued conservative therapy started before. 16 patients have been under observation for 1.5 -2 years and longer after transplantation, the rest 11 patients observed not less than 6 months. MSCintroduction gave positive clinical effects in all 27 cases: somatic status improvement, dyspnoea reduction, relieving of weakness and indisposition, putting on weight (24 cases). 3-4 months after transplantation bacterioexcretion was noticed to stop in 20 patients, in 11 patients long-termed cavities healed later. At present 9 of 16 patients who had MSC transplantation 1.5-2 years ago can be stated to have stable remission of tuberculosis, 6 patients of this group demonstrate significant positive bacteriological and morphological dynamics. Only in one of 16 cases MSC transplantation resulted in short clinical improvement. Thus, MSC transplantation as a part of antitubercular therapy can be perspective in enhancing treatment of patients with drug-resistant tuberculosis.

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.

Growth characteristics of human hemopoietic cells in erythremia and chronic myeloid leukemia were studied using agar cultures with and without hemopoietic growth factors. Agar cultures, similarly to cultures on other semisolid media (plasma clot, methylcellulose) can be used for early differential diagnosis of polycythemia vera (erythremia) and secondary erythrocytosis: erythremia, but not erythrocytosis, is characterized by spontaneous (erythropoietin-independent) formation of colonies from erythrocyte precursor cells. Spontaneous colony formation from granulocyte-macrophage precursor cells can serve as an important test for early diagnosis of chronic myeloid leukemia. The study of colony formation from granulocyte-macrophage precursors and of the capacity of bone marrow cells to form colonies from hemopoietic stromal precursor cells revealed new characteristics of the studied myeloproliferative diseases. Presumably, spontaneous colony formation from erythrocytic and myeloid precursors should be regarded as a sign of tumor transformation of the studied hemopoietic cells.

In patients with ovarian cancer, the colony-forming capacity and radiosensitivity of clonogenic tumor cells from the primary node and metastases (ascites) differed considerably.

We have carried out a study of the bone marrow status in both irradiated and non-irradiated zones of 56 patients with stage I-II Hodgkin's disease in complete 9-12 (33 patients, group 1) and 18-23 (23 patients, group 2) year remission after therapeutic irradiation of the supradiaphragmatic lymphatic collectors at a dose of 40 Gy with irradiation of the spleen (33 patients) or splenectomy (23 patients). The total count of myelokaryocytes, myelogram, a relative and absolute content of lymphoid cells, immature granulocytes and elements of erythroid series were calculated in the aspirates from the exposed to radiotherapy sternum and non-irradiated upper portion of the ileum. The number of granulocyte-macrophage (CFU-GM) and stromal (CFU-F) precursor cells were defined using in vitro culture technique. There was a complete annihilation of the bone marrow in the irradiated zones, when the dose exceeded 35 Gy in 3-4 weeks. The concentration of myelokaryocytes, immature granulocytes, erythronormoblasts, CFU-GM, CFU-F in non-exposed bone marrow were significantly lower in all patients of group 2 than in normal subjects and in group 1 patients. Absolute lymphoid count in patients with 18-23 year remission was found to be normal but was considerably reduced in comparison to patients of group 1. These changes may be the result of the previous hyperactivity of the non-irradiated bone marrow which could be a cause of stem cell compartment depletion. The differential calculation of compact and diffuse subpopulations of CFU-F revealed a significant reduction of compact colony-forming CFU-F in both irradiated and unexposed bone marrow. Almost all the stromal precursor cells from irradiated zone formed diffuse colonies in cultures. These results confirm experimental data concerning greater radiosensitivity and proliferative potential of CFU-F, forming compact colonies versus diffuse colony-forming CFU-F. Aplasia of the irradiated bone marrow and hypoplasia of the non-irradiated bone marrow 18-23 years after radiotherapy completion coexisted with normal circulating CFU-GM and granulocyte blood count suggesting a compensatory mechanism involving a mitotic amplification between the progenitor cell and the final differentiated cell.

The effect of gas hypoxic mixture, containing 8% of O2 (GHM-8), on the ability of cell precursors of haemopoietic stroma (which form colonies (clones) of fibroblasts (CFU-F) in a culture, and are present in the bone marrow of adult rats) to repair potentially lethal and sublethal radiation damages has been investigated. The recovery of CFU-F from potentially lethal damages, that was studied after their delayed survival in a culture following irradiation of animals, proceeds at nearly the same rate in cells irradiated both in the air and in hypoxic conditions (GHM-8). Fractionated irradiation reduces the radioprotective effect of GHM-8 for CFU-F, particularly for the radioresistant subpopulation; the ability of CFU-F to recover from sublethal radiation damages decreases.

The ability of cell precursors of the haemopoietic stroma (CFU-F), that are present in the bone marrow of adult rats, to recover from potentially lethal and sublethal radiation damages has been investigated. The highest reparability, with respect to potentially lethal damages, is displayed by the most radioresistant CFU-F population, that forms loose colonies (clones) in a culture; the slope of the dose-response curve, not the extrapolation number, changes, and heterogeneity of the CFU-F population is observed. The results obtained confirm the presence of heterogeneity in the population of CFU-F, that was revealed in studying their radiosensitivity by the formation of dense and loose fibroblast colonies in a culture.