D. V. Goldshtein

Clinical Study of the Efficiency of Combined Cell Transplant on the Basis of Multipotent Mesenchymal Stromal Adipose Tissue Cells in Patients with Pronounced Deficit of the Maxillary and Mandibulary Bone Tissue

The use of synthetic osteoplastic materials not always provides the required amount of the bone tissue. Transplantation of tissue-engineering constructs containing osteogenic precursor cells can be an alternative high-technology implantation method. Here we present the results of a pilot clinical study demonstrating safety of this method, accelerated healing of the operation wound, formation of young bone tissue after transplantation, and the possibility of mounting implants after 3 months in case of sufficient amount of the bone for primary fixation.

Role of VEGF-A in angiogenesis promoted by umbilical cord-derived mesenchymal stromal/stem cells: in vitro study

BackgroundMesenchymal stromal/stem cells derived from human umbilical cord (UC-MSCs) uniquely combine properties of embryonic and postnatal MSCs and may be the most acceptable, safe, and effective source for allogeneic cell therapy e.g. for therapeutic angiogenesis. In this report we describe pro-angiogenic properties of UC-MSCs as manifested in vitro.MethodsUC-MSCs were isolated from human Wharton’s jelly by enzymatic digestion. Presence of soluble forms of VEGF-A in UC-MSC-conditioned media was measured by ELISA. Effects of the conditioned media on human umbilical vein-derived endothelial EA.hy926 cells proliferation were measured by MTT-assay; changes in cell motility and directed migration were assessed by scratch wound healing and transwell chamber migration assays. Angiogenesis was modeled in vitro as tube formation on basement membrane matrix. Progressive differentiation of MSCs to endothelioid progeny was assessed by CD31 immunostaining.ResultsAlthough no detectable quantities of soluble VEGF-A were produced by UC-MSCs, the culture medium, conditioned by the UC-MSCs, effectively stimulated proliferation, motility, and directed migration of EA.hy926 cells. In 2D culture, UC-MSCs were able to acquire CD31+ endothelial cell-like phenotype when stimulated by EA.hy926-conditioned media supplemented with VEGF-A165. UC-MSCs were capable of forming unstable 2D tubular networks either by themselves or in combinations with EA.hy926 cells. Active spontaneous sprouting from cell clusters, resulting from disassembling of such networks, was observed only in the mixed cultures, not in pure UC-MSC cultures. In 3D mode of sprouting experimentation, structural support of newly formed capillary-like structures was provided by UC-MSCs that acquired the CD31+ phenotype in the absence of exogenous VEGF-A.ConclusionThese data suggest that a VEGF-A-independent paracrine mechanism and at least partially VEGF-A-independent differentiation mechanism are involved in the pro-angiogenic activity of UC-MSCs.

Expression of NMDA receptors in multipotent stromal cells of human adipose tissue under conditions of retinoic acid-induced differentiation

The system of NMDA glutamate receptors in human adipose tissue multipotent stromal cells and SH-SY5Y human neuroblastoma cells was used as a model for studies of NMDA receptor expression during neurodifferntiation. Glutamate NMDA receptors were detected in multipotent stromal cells of human adipose tissue. The expression of NR1 subunits of NMDA receptors increased significantly after 6-day incubation of multipotent stromal cells of human adipose tissue with 10 µM retinoic acid. Only NR1 subunits of NMDA receptors were expressed in SH-SY5Y neuroblastoma cells. Incubation with retinoic acid did not promote the appearance of mRNA of other subunits (NR2A-D, NR3). The results indicate that expression of NMDA receptors can serve as an indicator of neuronal differentiation of cells and as a marker of the efficiency of neuronal differentiation protocol.

Preparation and characterization of culture of CD146+ cells from human adipose tissue

A method for isolation of homogenous culture of cells expressing CD146 marker from adipose tissue lipoaspirate was developed. The resultant clonogenic cultures retained high proliferative activity, immunophenotype, and morphology after numerous passages. The presence of insulin in the medium served as the selective factor for maintenance of the population phenotype. These cultures effectively differentiate into CD31+ endothelial cells and can be used in regenerative medicine.

Transplantation of allogenic cells in the therapy of patients with dilated cardiomyopathy

We carried out a pilot study on intracoronary transplantation of prenatal allogenic skeletal myoblasts and multipotent bone marrow stromal cells to patients with dilated cardiomyopathy. Intracoronary transplantation of allogenic cells is a feasible and safe procedure: there were no life-threatening rhythm and conduction disturbances, symptoms of hemodynamic instability, and thromboembolic complications. Positive clinical effect of cell transplantation persisted for 6 months and consisted in decreased content of brain natriuretic peptide and improved tolerance to physical exercises. We observed no reliable dynamics of the major echocardiographic parameters and their correlations with patient’s status.

Reparative Osteogenesis during Transplantation of Mesenchymal Stem Cells

Reparative osteogenesis was studied after xenotransplantation of suspension cell graft from human mesenchymal stem cells. A model of experimental damage to rat femoral diaphysis was developed. The state of animals was satisfactory and non-depressed in the early and late postoperation period. We revealed no local pathological reactions and complications. Administration of mesenchymal stem cells into the area of bone defect accelerated and improved regeneration. Unilateral transplantation of the cell graft stimulated regeneration in the contralateral limb due to acceleration of bone tissue maturation. On day 90 after treatment the bone regenerate was completely developed in the area of defect in animals of various groups. The newly formed bone tissue was well integrated into the bone organ.

Bone marrow-derived multipotent stromal cells promote myocardial fibrosis and reverse remodeling of the left ventricle.

Cell therapy is increasingly recognized as a beneficial practice in various cardiac conditions, but its fundamentals remain largely unclear. The fates of transplanted multipotent stromal cells in postinfarction cardiac microenvironments are particularly understudied. To address this issue, labeled multipotent stromal cells were infused into rat myocardium at day 30 after myocardial infarction, against the background of postinfarction cardiosclerosis. Therapeutic effects of the transplantation were assessed by an exercise tolerance test. Histological examination at 14 or 30 days after the transplantation was conducted by means of immunostaining and quantitative image analysis. An improvement in the functional status of the cardiovascular system was observed after both the autologous and the allogeneic transplantations. Location of the label-positive cells within the heart was restricted to the affected part of myocardium. The transplanted cells could give rise to fibroblasts or myofibroblasts but not to cardiac myocytes or blood vessel cells. Both types of transplantation positively influenced scarring processes, and no expansion of fibrosis to border myocardium was observed. Left ventricular wall thickening associated with reduced dilatation index was promoted by transplantation of the autologous cells. According to the results, multipotent stromal cell transplantation prevents adverse remodeling and stimulates left ventricular reverse remodeling.

Induction of Osteogenic Differentiation of Multipotent Mesenchymal Stromal Cells from Human Adipose Tissue

We studied of osteogenic differentiation of multipotent mesenchymal stromal cells from human adipose tissue. Experiments showed that 1α,25-dihydroxycalciferol is a more effective inductor of osteogenesis than dexamethasone. Comparative analysis revealed activation of gene expression for the major osteogenic markers on day 7 of culturing in a medium containing 1α,25-dihydroxycalciferol. It was found that transcription of genes encoding type 1 collagen proteins, osteopontin, osteocalcin, and bone sialoprotein peaked on day 14 in culture, while the expression of alkaline phosphatase and bone morphogenetic protein-2 genes increased over 21 days. Intensive mineralization of the extracellular matrix was observed starting from day 14 in culture. On the basis of the analysis of these data, optimal terms for osteogenic induction (day 14) and an optimal inductor (1α,25-dihydroxycalciferol) were chosen and the protocol of effective osteogenic differentiation of multipotent mesenchymal stromal cells from human adipose tissue was developed for creation of tissue-engineered bone equivalents.

Isolation of Insulin-Producing Cells from Different Populations of Multipotent Stromal Cells of the Umbilical Cord and Human Adipose Tissue

Stromal cells of adipose tissue and human umbilical cord were isolated by the original method from general populations of multipotent subpopulation of multipotent stromal cells exhibiting perivascular phenotype (CD146+, CD31−). Effective directed differentiation of these cells into insulin-producing cells by transient transfection of the gene Pdx1 was demonstrated. Transfection multipotent stromal cells CD146–, CD31– derived from adipose tissue and umbilical cord and isolated by the standard method, did not result in activation of insulin gene transcription. It was shown that the expression of nestin was not necessary for effective pancreatic cell differentiation.

Molecular Survey of Cell Source Usage during Subtotal Hepatectomy-Induced Liver Regeneration in Rats.

Proliferation of hepatocytes is known to be the main process in the hepatectomy-induced liver regrowth; however, in cases of extensive loss it may be insufficient for complete recovery unless supported by some additional sources e.g. mobilization of undifferentiated progenitors. The study was conducted on rat model of 80% subtotal hepatectomy; the objective was to evaluate contributions of hepatocytes and resident progenitor cells to the hepatic tissue recovery via monitoring specific mRNA and/or protein expression levels for a panel of genes implicated in growth, cell differentiation, angiogenesis, and inflammation. Some of the genes showed distinctive temporal expression patterns, which were loosely associated with two waves of hepatocyte proliferation observed at 2 and 7 days after the surgery. Focusing on genes implicated in regulation of the progenitor cell activity, we came across slight increases in expression levels for Sox9 and two genes encoding tumor necrosis factor-like cytokine TWEAK (Tnfsf12) and its receptor Fn14 (Tnfrsf12a). At the same time, no increase in numbers of cytokeratin 19-positive (CK19+) cells was observed in periportal areas, and no CK19+ cells were found in hepatic plates. Since CK19 is thought to be a specific marker of both cholangiocytes and the hepatic progenitor cells, the data indicate a lack of activation of the resident progenitor cells during recovery of hepatic tissue after 80% subtotal hepatectomy. Thus, proliferation of hepatocytes invariably makes the major contribution to the hepatic tissue recovery, although in the cases of subtotal loss this contribution is distinctively modulated. In particular, induction of Sox9 and TWEAK/Fn14 regulatory pathways, conventionally attributed to progenitor cell activation, may incidentally stimulate mitotic activity of hepatocytes.