Differences in Protein Secretion by Multipotent Mesenchymal Stromal Cells Effective and Ineffective in the Prevention of Acute Graft-Versus-Host Disease after Allogeneic Hematopoietic Stem Cell Transplantation.

Multipotent mesenchymal stromal cells (MSC) were administered to patients after allogeneic hematopoietic stem cell transplantation to prevent the development of acute graft-versus- host disease (GVHD). The injection of MSC did not always prevent the development of GVHD. The aim of the work was to compare the secretome of MSC effective and ineffective in the prevention of GVHD. MSC were obtained from the bone marrow of hematopoietic stem cells donors. The secretome was studied using a TripleTOF 5600+ mass spectrometer with a NanoSpray III ion source coupled to a NanoLC Ultra 2D Plus nano-HPLC System. A total of 1,965 proteins were analyzed. Analysis of the secretome of effective and ineffective MSC samples revealed significant differences in the secretion of 1,119 proteins associated with ribosomes, exosomes, focal contacts, and others. Analysis of proteins secreted by MSC can be used to identify prognostically effective samples.

In vitro histogenesis of human embryonic stem cells into retina components.

We developed a protocol of in vitro differentiation of human embryonic stem cells into three-dimensional structures histologically and molecularly similar to the developing retina.

[Protein kinases abundantly expressed in undifferentiated human ESC lines and derived embryoid bodies].

The ability of human embryonic stem cells (ESCs) to unlimited proliferation and huge differentiation potential makes them very attractive tool both for basic research and biological medicine. There are still little known about mechanisms that govern their differentiation or keep them in a pluripotency state. A variety of signaling events determines gene expression profiles responsible for such mechanisms activation. Protein kinases are key components of the signaling cascades. The knowledge about protein kinases expression profile in undifferentiated ESCs and embryoid bodies (EBs) will allow to understand early differentiation events. We constructed cDNA libraries containing fragments of protein kinases catalytic domain that were expressed in undifferentiated cells or EB of hESM01, hESM02 cell lines. We detected high level of MAK-V expression using Northern-blot hybridization. Semi-quantitative RT-PCR was used to compare the level of abundantly expressed kinases MAK-V, A-RAF-1, MARK3, IGF1R, NEK3 and NEK7 in undifferentiated ESCs or derived EBs.

Cultures of hESM human embryonic stem cells: chromosomal aberrations and karyotype stability.

Cytogenetic analysis of karyotypes of hESM01-hESM04 human embryonic stem cells and substrains derived from these strains showed that all these strains retained normal karyotype during long-term culturing. Two substrains of embryonic stem cells with chromosome aberrations indicating clonal origin of these strains were detected. The potentialities of using analysis of chromosome variability of embryonic stem cells for evaluation of predisposition of the corresponding genotypes to the formation of chromosome abnormalities are discussed.

Characteristics of human bone marrow mesenchymal stem cells isolated by immunomagnetic selection.

Immunophenotype of human bone marrow mesenchymal stem cells was studied after several culturing passages and after cryopreservation. Immunocytochemical analysis showed that bone marrow mesenchymal stem cells acquired homogeneity during in vitro culturing, but initially contained heterogeneous populations.

[A study of structural rearrangements of chromatin fibrils using the intercalation of ethidium bromide and chloroquine diphosphate]. / Issledovanie strukturnykh perestroek fibrill khromatina s pomoshch'iu interkaliatsii bromistogo étidiia i difosfata khlorokvina.

Structural rearrangements of chromatin resulting from changes in axial twisting of internucleosomal linkers were studied using the intercalators of ethidium bromide and chloroquine diphosphate. It was determined how the modifications of the primary structure affect the compactization of chromatin fibrils. The data obtained suggest that changes in the relative angle of rotation between nucleosomes result in changes in the spatial organization of chromatin fibrils. In this case, the modification of terminal domains can substantially affect the course of this process.

[Serological study of a repertoire of human cancer antigens and autoantigens]. / Serologicheskie issledovaniia reperatura rakovykh antgenov i autoanigenov cheloveka.

The spectrum of human antigens allows a monitoring of various pathological processes such as autoimmune disorders and tumorigenesis. Serological analysis of cDNA expression libraries (SEREX) is now used to search for new cancer-associated antigens, which are potential diagnostic markers or targets for immunotherapy of cancer. The results obtained for several solid tumors are reviewed. Groups of antigens detectable by SEREX, causes of immunogenicity of autoantigens, and prospective implication of antigens in diagnostics and monitoring of cancer are discussed.