[Igf-1 and its isoform expression in hepatic cell tumors and the surrounding tissue in mice liver carcinogenesis induced by diethylnitrozamine].

The expression of the Igf-1 gene in mice liver at different stages of development of hepatocellular carcinoma induced by diethylnitrozamine--from the initial diffuse tissue dysplasia and nodular hyperplasia to the development of multiple adenomas and carcinoma--has been analyzed. It was marked that the level of Igf-1 expression in all liver neoplasms decreased; it increased only in the liver tissue surrounding the carcinoma. The dependence of Igf-1 expression on inflammatory processes accompanying tumor growth was analyzed on the model of acute liver damage by diethylnitrozamine. It was established that the level of Igf-1 expression in liver tissue under acute damage in sexually mature mice was the same as in the control group. By the means of semiquantitative evaluation of the products of two Igf-1 splice isoforms--locally active (Mgf) and circulating (Igf- 1v4)--it has been shown that the amount of mRNA of both isoforms in hepatocellular carcinoma was lower, and in tissue surrounding the tumor higher, than in the samples of the control group. At the same time, the proportion of transcripts of isoforms was stable.

[Interaction of the ss and CG5017 genes in the regulation of morphogensis of limbs in Drosophila melanogaster].

The influence of the P-element built into the area of the CG5017 gene on the mutation of the spineless (ss) gene was studied. It was shown that the insertion of the P-element decreased the level of transcription of CG5017 approximately twofold. Modulation of the level of transcription of the CG5017 gene helped demonstrate, for the first time, its influence on the phenotypic manifestation of the mutation of the ss gene, which shows their interaction in the process of regulation of morphogenesis of limbs in Drosophila melanogaster.

[Molecular genetic and immunophenotypic analysis of antigen profiling, osteogenic and adipogenic potentials of mesenchymal stromal cells from fetal liver and adult bone marrow in rats].

Comparative characteristics of mesenchymal stromal cells (MSC) from fetal liver and adult bone marrow are of great interest due to similar contribution to organization of the hematopoietic microenvironments in these organs in different developmental periods. It is known that MSC play a pivotal role in organization of hematopoietic stem cells "niches". Moreover, the histogenetic affinity between MSC from both sources is not ruled out. Antigen profiling using immunocytochemistry and RT-PCR confirmed that cell populations under study corresponded to MSC criteria and had no hematopoietic, lymphoid and endothelial cells after second passage. Comparative analysis of osteogenic and adipogenic marker expression revealed distinct differentiation potentials of MSC from two hematopoietic organs: adipogenic potentials of hepatic MSC was weaker but ability to differentiate to osteogenic lineage was extremely low, if any, in comparison with marked osteo- and adipogenic potentials of adult bone marrow MSC. Similar cell phenotype but unequal differentiation potentials under identical conditions in vitro may be attributed to a distinct developmental program in pre- and postnatal histogenesis of MSC from different sources.

[Comparative characterization of mesenchymal bone marrow stromal cells at early and late stages of culturing].

The mesenchymal stromal cell is a multipotent precursor of osteoblasts, adipocytes, and some other cell types. In this study, a comparative analysis of cultured mesenchymal stromal cells from the rat bone marrow at the early and late stages of subculturing has been performed using molecular genetic and cytological methods. The culture has undergone 11 passages during 140 days. Upon long-term culturing, the mesenchymal stromal cells have proved to lose their potential for adipogenic differentiation but preserve the potential for osteogenesis. Morphological characters typical of osteogenic differentiation can be observed at the earlier stages of culturing (passages 1-4) but disappear at later stages (passages 9-11), despite mineralization of the extracellular matrix and the expression of osteogenic differentiation markers. A comparative analysis of the proliferation potential of stromal cells has shown that differences in the period of cell population doubling at the early and later stages of culturing are insignificant. An almost complete arrest of cell growth has been observed in the middle of the culture period (passages 5 and 6).

[Molecular and genetic regulation of osteogenic differentiation of mesenchymal stromal cells].

The review summarizes current concepts concerning the molecular genetic mechanisms of the osteogenic differentiation of mesenchymal stromal cells, which is controlled by a complex of signaling proteins and transcription factors. The interaction of regulatory factors involved in the most important signaling pathways at different stages of this differentiation is discussed.

[Constructive synergism of regulatory genes expressed in the course of the eye and muscle development and regeneration]. / Konstruktivnyi sinergizm ékspressiruiushchikhsia reguliatornykh genov v protsesse razvitiia i regeneratsii glaza i myshts.

The expression patterns of regulatory genes involved in the formation of the eye in Drosophila and vertebrates during early development were analyzed comparatively. The results demonstrated that, although the compound eyes of invertebrates and the camera eyes of vertebrates markedly differ in their structure and development, they exhibit a striking similarity at the molecular level. This similarity manifests itself in the fact that the homologous regulatory genes ey/Pax, eya/Eya, dac/Dac, and so/Six, which control the early stages of eye development, are expressed in both groups. Not only was synergism shown in the expression of early regulatory genes, but direct interactions of ey/Pax- and so/Six-encoded transcription factors with DNA and protein-protein interactions between nuclear transcription factors encoded by eya/Eya and dac/Dac were also revealed. Transcription factors produced by expressing gene cascades--ey/eya/dac/so in invertebrates and Pax/Eya/Dac/Six in vertebrates--from the transcription complexes that control eye morphogenesis. Paradoxically, the development of muscles in vertebrates proved to involve the expression of genes homologous to the same regulatory genes that control eye morphogenesis in invertebrates and vertebrates. In the developing muscles, regulatory genes also produce transcription factors that form transcription complexes with the mechanism of action based on protein-DNA and protein-protein interactions. The processes of regeneration in the eye and skeletal muscles are controlled by the homologues of the same regulatory genes. Thus, the Pax/Eya/Dac/Six regulatory network is a general system involved in regeneration as well as in development.

[Crystallins: recruiting proteins to perform new functions]. / Kristalliny: rekrutirovanie belkov dlia vypolneniia novykh funktsii.

The main properties of major water-soluble proteins of the lens, i.e., crystallins, include high ability to aggregation and stability. It is these properties of crystallins which are required for the formation of the transparent lens and maintenance of lens transparency over the whole lifespan of the animal.

[Identification of new genes and analysis of their expression during lens and retinal regeneration in adult newts]. / Identifikatsiia novykh genov i analiz ikh ékspressii v protsessse regeneratsii khrustalika i setchatki u vzroslykh tritonov.

During lens regeneration in Pleurodeles waltl, the dorsal iris zone is the cell source of the lens regeneration, while the ventral iris zone can serve as the cells' source of lens regeneration only under certain experimental conditions. The method of subtractive hybridization was used for the identification of genes responsible for the different proliferative potential of these zones. Differential screening of the enriched cDNA libraries, which were obtained as a result of subtractive hybridization of the cDNA samples of the ventral and dorsal iris zones 14 days after lens removal, revealed four clones specific to the dorsal iris and six clones specific to the ventral iris. Two of these, LeR-1 and VeR-1, were structurally characterized. Comparison of their primary structure with data from the Gene Bank showed no essential homology with the known sequences. Time-related changes in LeR-1 and VeR-1 expression were shown during lens regeneration. LeR-1 and VeR-1 expression was activated at the early stages of lens regeneration. The peaks of LeR-1 and VeR-1 expression were observed on the 14th day of lens regeneration in the dorsal and ventral iris zones, respectively. Furthermore, LeR-1 is activated during retina regeneration. The results of Southern hybridization suggest the presence of sequences complementary to LeR-1 in the genomes of Pleurodeles waltl and Rana temporaria. We propose that the activation of LeR-1 expression is related to the triggering of lens regeneration, while the activation of VeR-1 expression accompanies the inhibition of proliferative activity in the ventral iris zone.

[Molecular-biological approaches to studying gene expression during regeneration]. / Molkeuliarno-biologicheskie podkhody v issledovanii ékspressii genov v protsesse regeneratsii.

This paper constitutes a review of the methodical approaches allowing analysis of the mechanisms underlying development and differentiation. Progress in investigation of the mechanisms underlying embryogenesis is related to the discovery of genic families in the Drosophila genome, which are responsible for different periods of embryogenesis. The true revolution in studies of developmental mechanisms began with the application of molecular-genetic methods for analysis of Drosophila mutant lines. The clarification and analysis of the genes controlling regeneration is one of the most effective paths toward an understanding of the mechanisms underlying regeneration. No mutations affecting regeneration are, and the development of alternative (i.e., not based on mutation analysis) methods of discovery of the genes controlling regeneration is necessary for investigation of the genetic mechanisms of regeneration. The advantages and drawbacks of the two main approaches for discovery of the genes controlling regeneration are considered. The first approach is based on the production of a bank of sequences expressed in the regenerating structures and subsequent screening of the bank by the known probes. This approach also involves analysis of the structure, function, and expression pattern of the obtained homologs. The second approach is based on subtractive hybridization, which allows identification of the genes specifically expressed in the regenerating structures. This approach was made it possible to identify, for the first time, new genes specifically expressed during lens and retina regeneration in amphibians.

[The taxon-specific lens protein of the frog eye: its phylogenetic kinship with the proteins of the NADP-dependent reductase family]. / Taksonospetsificheskii belok khrustalika glaza liagushki: filogeneticheskoe rodstvo s belkami semeistva NADP-zavisimykh reduktaz.

Physicochemical and molecular-biological properties of the proteins from the family of NADP-dependent reductases are reviewed in the article. Physicochemical properties of aldehyde/aldosoreductases are well studied. Information on the genes, coding for these proteins has appeared recently as well. Comparison of the protein structures has revealed, that taxon-specific protein of the frog lens-rho-crystallin--is structurally related to the superfamily of NADP-dependent reductases, though it does not have an enzymatic activity. Sequence alignment reveals a set of clusters, conserved in all members of superfamily. Among them there are two highly conserved regions, providing for binding of NADP coenzyme. Secondary structure of the proteins is similar as well. All the members of superfamily predominantly have beta-sheets. Comparison of structural data for proteins, isolated from various organisms from bacterium to human, suggests phylogenetic relatedness of all the members of superfamily, including rho-crystallin. All the data presented enable to suppose, that rho-crystallin and other members of superfamily have a common ancestor gene. A set of successive duplications and mutations of the ancestor gene resulted in the appearance of rho-crystallin gene, that has lost the enzymatic activity and acquired the ability for tissue specific superexpression in the lens cells.