Biomedical subjects

G P Pinaev

Publications and source records attributed to G P Pinaev.

At least 19 recordsLinked to original sources

PubMed2006

[Elaboration of biodegradable polymer substrate for cultivation of human dermal fibroblasts].

The influence of polylactic acid (PLA) surface films on the pattern of cell behavior was studied. The human dermal fibroblasts were cultivated on PLA covered glasses. The hydrophobic nature of PLA films depends on the availability of polymer solvent in the film preparation. PLA films obtained from a more polar solvent--aceton--appeared to be more hydrophilic than those obtained from methylene chloride. More hydrophilic polymer films also appeared to be more preferable for cell cultivation, and human dermal fibroblasts demonstrated a better adhesion and proliferation on hydrophilic rather than on hydrophobic PLA films.

Acetone↗

PubMed2006

[The analysis of cellular elements in coelomic fluid during early regeneration of of the starfish Asterias rubens L].

Three main cell types were found in the coelomic fluid (CF) of intact starfishes: agranulocytes (55-80%) varying in size and form (spherical and ovoid) and with occasional pseudopodia, granulocytes (15-45%), and small cells (up to 2 %) with a high nuclear-cytoplasmic ratio. The starfish response to injury depends on the degree of coelomic fluid loss. After a slight wounding, when only insignificant portion of CF is lost, the cellular composition of circulating fluid changed only slightly. Unlike, a significant injury resulted in rising the share of small cells, regarded presumably as young cells. Besides, after injury the functional characteristics of SF also changed: the proportion of cells with decondensed chromatin and stained nucleoli increased, and coelomocytes acquired ability to form nets at adhesion. Moreover, some new cell types can be found (fusiform cells), with granulocyte proportion in nets increasing. We suppose that after slight wounding circulating coelomocytes may restore from the existing store of differentiated cells beyond the circulation, whereas after significant injury young undifferentiated coelomocytes are involved in the process of restoration.

Animals↗

PubMed2006

[Isolation of human basal keratinocytes by selective adhesion to extracellular matrix proteins].

Epidermal human cells (keratinocytes) differently interact with extracellular matrix proteins of the skin basal membrane depending on the stages of their differentiation. The pool of basal keratinocytes commonly includes stem cells and transient amplifying cells. They directly attach to the skin basal membrane. Keratinocytes change their adhesive properties during differentiation, lose direct interaction with the basal membrane and move to suprabasal epidermal strata. From this, it is suggested that basal and primarily stem cells can be isolated from a heterogenous keratinocyte population due to their selective adhesion to the extracellular matrix proteins. In the current study, we analysed the specificity of interaction between primary keratinocytes and extracellular matrix proteins (collagens of I and IV types, laminin-2/4, fibronectin and matrigel). We have demonstrated that the basal keratinocytes extracted from the skin have different adhesive abilities. The rapidly spreading cells usually interacted with collagen and fibronectin rather that with laminin-2/4 or matrigel. The majority of these cells being represented by basal keratinocytes. Our data demonstrate that the applied method of keratinocyte selection may be directed for precise isolation of skin stem from a common cell population.

Cell Adhesion↗

PubMed2006

[The filamin in cell signaling].

This review describes structure and functions of the group of actin-binding proteins--the filamins. Up-to-date facts demonstrate that filamis take part in different regulatory processes in the cell. The filamins have diverse functions--organization of actin polymers into orthogonal networks (three-dimensional scaffolding), attachment of actin filaments to transmembrane receptors, regulation of actin-myosin interaction, regulation of actin assembly. In addition to its main role of the cytoskeleton structural protein, filamin can serve as scaffold protein for formation of signal proteins complexes. One interacts with transcription factors and takes part in signal transduction from cytoplasmic membranes to the nucleus. C-terminal end of filamin interacts with androgen receptor and through cleavage by calpain translocates to the nucleus. Analysis of reviewed experimental dates suggests the conception that intracellular signalization mediated by cytoskeleton proteins is connected with reorganization of the cytoskeleton.

Actins↗

PubMed2006

[Dynamic of DNA-binding activity of transcription factors in A431 cells during their spreading on immobilized ligands].

Dynamics of actin cytoskeleton in A431 cells and specific NF-kappaB SRF and AP-1 DNA-binding activities were studied during a 2 h spreading of these cells on fibronectin, laminin-2/4 or an antibody to epidermal growth factor receptor. Cell spreading was shown to be accompanied by sequential formation of actin cytoskeleton structures, whose spatial organization depends on the type of immobilized ligand. We have determined the time intervals, within which certain forms of cytoskeleton do not change qualitatively and are specific for dominant part of cell population. It has been shown that DNA-binding activities of the above transcription factors studied oscillate during cell spreading. The cycles of DNA-binding activity were found to be equel to 15-40 min. The character of oscillations depends on both transcription factor and ligand type. The temporal comparison of presses of actin cytoskeleton formation and DNA-binding activity of NF-kappaB and SRF times suggest that actin cytoskeleton reorganization may be presumably associated with activation of NF-KppaB and SRF.

Actins↗

PubMed2005

[Continuous human embryonic stem cell lines].

A new continuous human embryonic stem cell line (HESC-5) derived from a blastocyst is described. The cultured cell passed over 200 population doublings, which exceeds the Hayflick's limit sufficiently. The cells maintained a stable proliferative activity, high activity of alkaline phosphatase, and expression of transcription factor Oct-4 and of surface antigens SSEA-3, SSEA-4 and TRA-1-60 known to be characteristic of embryonic stem cells of the human origin. Immunofluorescent detection of antigens, characteristic of ectoderm, endoderm and mesoderm in the new cell line HESC-5, and in the previously described other four stem cell lines confirms the ability of these cells to retain their pluripotency under in vitro condition. In addition, in all the cell lines, a high telomerase activity was revealed, which controls a stable telomere length and, hence, an unlimited ESC proliferation. Unlike other cell lines, HESC-5 was found, under specific conditions, to spontaneously differentiate into hematopoietic cells. A morphological similarity was shown between ESC colonies cultivated both on a feeder layer and in the non-feeder system.

Blastocyst↗

PubMed2005

[SRE, NF-kappaB, and AP-1 DNA-binding activities induced by A431 cell adhesion correlate with actin cytoskeleton reorganization].

Cell adhesion to extracellular matrix proteins induces activation of different signal molecules and influences gene expression. As shown earlier, epidermoid carcinoma A431 cell adhesion to fibronectin, laminin-2/4 or antibodies to receptor EGF (ab EGFR) results in reorganization of specific cell shape and actin cytoskeleton in the majority of cells. This study resolves a question whether morphological changes are accompanied with some cell response at the level of gene expression in nuclei. We have shown that cell reattachment promotes a specific DNA-binding of nuclear extracts with consensus sequences SRE, NF-kappaB and AP-1, compared to the control. NF-kappaB and AP-1 activities were considerably reduced in spread cells, which did not show actin filament's structures typical for the ligands. SRE specific proteins demonstrated other peculiarities and depended on the type of immobilized ligands. Our results argue that actin cytoskeleton reorganization, induced by cell adhesion to immobilized ligands at the early period after cell reattachment, is correlated with a specific answer at the levels of DNA-binding activity of transcription factors SRE, NF-kappaB and AP-1.

Actins↗

PubMed2005

[Participation of transfused bone marrow cells in reparative osteohistogenesis].

The participation of skeletal tissue cell precursors in the repairing regeneration of bone tissue was studied. Bone marrow was taken from donor animals--mice of C57Bl/6-TgN(ACTbGFP) 1 Osb line (The Jackson Laboratory Bar Harbor ME USA line). Nucleated cell fraction was isolated by centrifugation on a density percoll gradient. Recipient mice C57Bl/6 line were irradiated by 7.0-7.5 Gr dose. Intravenous infusion of donor cells and osteoclasts of tibia was done after irradiation of recipient mice. Histological preparations of bone regenerate tissues were studied on 15, 30, and 60 days by confocal microscopy. Donor cells were found as skeletal tissue precursors into periost, endost, bone marrow, and as differentiated cells of newborn tissue of regenerate--osteoblasts, osteocytes, chondrocytes. The data obtained indicate that part of donor bone marrow cells are able to progressive differentiation under recipient bone fractures.

Animals↗

PubMed2005

[The effect of immobilized fibronectin on karyotypic variability in the skin fibroblast cell subline of indian muntjac].

The numerical and structural karyotypic variability has been investigated in the Indian muntjac skin fibroblast cell subline MT on cultivating cells on the fibronectin-coated surface. In cell subline MT, cultivated on the fibronectin-coated surface for 1 and 2 days, the character of cell distribution for the chromosome number did not change. In 3, 4 and 8 days, the character of cell distribution for the chromosome number changed. These changes involve a significant decrease in frequency of cells with modal numbers of chromosomes, and an increase in frequency of cells with lower chromosome numbers. Many new additional structural variants of the karyotype (SVK) appear. The observed alterations seem to be due to both disturbances of mitotic apparatus and selection of SVK, which are more advantageous to changed culture conditions of the cell population. Detachment of cells from the fibronectin-coated surface, followed by a 1 day cultivation on a hydrophilic surface, commonly used for routine cell cultivation, does not restore the control cell distribution for the chromosome number, but cultivation in these conditions for 5 days restore control distribution. The frequency of chromosomal aberrations on cultivation on the fibronectin-coated surface for 3 and 4 days significantly increases, mainly at the expence of dicentrics (telomeric association). On prolongating the time of cultivation up to 8 days on the fibronectin-coated surface the frequency of chromosomal aberrations approaches the control value. Structural instability of chromosomes at cultivation on the fibronectin-coated surface demonstrates nonspecific reaction of "markerless" cell lines to unfavourable factors of the environment. We discuss possible reasons of differences in the character of karyotypic variability in cell lines of the Indian muntjac skin fibroblasts on cultivating on laminin and fibronectin.

Animals↗

PubMed2004

[Morphology of epidermoid carcinoma A431 cells spread on immobilized ligands].

Cell interaction with extracellular matrix is a multi-step process characterized by cell attachment to substrata with subsequent cell spreading accompanied by actin cytoskeleton and cellular membrane receptor reorganization. It has been shown elsewhere that epidermoid carcinoma A431 cells, spread on solid substrata coated with fibronectin, laminin-2/4 or antibodies to EGF receptor, form specific actin filament structures typical for each particular ligand. Here quantitative analysis of heterogeneous A431 cell population spread on the above ligands has been reported. Cells were subdivided into morphological classes, according to their shape and actin filament structure, and the relationship among classes under various experimental conditions were quantitatively estimated for every ligand. We studied the influence of cell detachment pattern, short-term and long-term starvation, and cell incubation in suspended state in the medium before plating on the cell population composition. It was possible to recognize the modal morphological class of cells with typical actin cytoskeleton structure dominating for the ligand in the population. Long-term starvation and incubation in suspension before cell spreading are considered as the crucial experimental parameters leading to dramatic changes in cell population.

Actin Cytoskeleton↗

PubMed2004

[Endothelial vascular grafts (Experimental research)].

The authors present herein their findings obtained in bench-test and experimental studies, which made it possible to work out an original technology of creating an endothelial covering of the inner surface of vascular grafts made of polytetrafluorethylene. The new technology includes the definite sequential processes which are as follows: 1) creation of vascular endotheliocytes; 2) stimulation of growth and reproduction of endotheliocytes; 3) preparation of the graft, including creation of stable positive potential on its inner surface in order to create optimal conditions for endothelization; 4) graft endothelization itself. In order to assess efficacy of endothelial vascular grafts, we carried out a total of 105 experiments on dogs. The experimental conditions made it possible to comparatively study the standard and endothelialized grafts using them in the position of the aortic abdominal portion, carotid and femoral arteries. The new grafts turned out to possess satisfactory performance properties, which precluded formation of thromboses and hyperplasia of the noeintima, simultaneously providing good implantability.

Blood Vessel Prosthesis↗

PubMed2004

[Development and morphofunctional characterization of the osteoblastic phenotype in cell culture in vitro].

The objective of this research was to study osteogenic properties of cultured rabbit bone marrow stromal cells, newborn rat cranium bone cells and rat osteocarcoma ROS 17-2/8 cells. For this purpose cytochemical reaction for alkaline phosphatase was performed by the Lowry method, mineral deposition was assessed by staining of the cultures after von Kossa. Cranium bone cells were shown to synthesize alkaline phosphatase (34 +/- 7 nmol/min/10(6) cells), the matrix mineralization being found. Bone marrow stromal cells displayed a lower activity alkaline phosphatase level than did cranium bone cells (4 +/- 0.6 nmol/min/10(6) cells). However, cell cultivation in the presence of dexamethasone in the medium (10(-8) M) induced a higher activity of alkaline phosphatase (9 +/- 1 nmol/min/10(6) cells), mineralization of the extracellular matrix being the case. The highest level of alkaline phosphatase activity was found for ROS 17-2/8 cells (60 +/- 12 nmol/min/10(6) cells) but no matrix mineralization was determined. According to these data, matrix calcification and formation of bone-like nodules are the most important properties of osteoblastic differentiation in vitro.

Alkaline Phosphatase↗

PubMed2004

[Lamellar bone culture in vitro].

The objective of this study was to analyze morpho-functional characteristics of the cells in definitive osseous tissue cultured in vitro. Cortical plates, isolated from the fragments of iliac bones of adult rabbits, were cultured in vitro in a nutrient medium. The culture obtained was fixed after 3, 10 and 20 days and processed for scanning electron microscopy. To identify the osteogenic cells, alkaline phosphatase activity was demonstrated. It was established that the processes of cell proliferation and migration from the cultured bone pieces were most active at 10 days after the explanation. The growing cells formed a growth zone around the bone fragment that consisted of three layers, differing in the degree of cellular proliferation and differentiation. After 20 days in culture the cells expressing alkaline phosphatase were shown to form groups. The cells of osteon canals in culture were found to possess potential for proliferation and osteogenic differentiation.

Alkaline Phosphatase↗

PubMed2004

[Changes in human burn fluid biological activity during normal burn healing].

The main goal of this work was monitoring the changes occurring in human burn fluid biological activity during normal burn healing. The fluid available in the burn until healing makes a good material for controlling biochemical microenvironment of burn cells. This environment involves factors, such as extracellular matrix proteins and matrix metalloproteinases. In this work our previous studies of the influence of wound and burn fluids on the functional activity of cells were extended to include the effect of burn fluid on fibroblasts and keratinocytes, i. e. human skin cells present in the wound and involved in wound healing. It was shown that human burn fluid biological activity depends on the time that passed after burning, and on the correctness of healing. Migration of human fibroblasts becomes more intensive under the influence of such a fluid independently on the time of fluid sampling. Unlike, keratinocyte migration was inhibited by burn fluid sampled 1-3 days after burning but was enhanced by fluids sampled 6 days following burning. The obtained data are to be necessarily taken into consideration at burn treatment and also at transplantation of cells for healing of wounds of different nature.

Biological Factors↗

PubMed2004

[Intracellular distribution of tyrosine-phosphorylated actin-binding proteins in A431 cells spread on different ligands].

Spreading A431 cells on extracellular matrix elements fibronectin, laminin 2/4 and antibody to EGF receptor (5A9 clone) leads to tyrosine phosphorylation of actin-binding proteins, which participate in focal adhesions formation. Tyrosine phosphorylation of the proteins is retained for 1 h of cell spreading. When cells interact with ligands, focal adhesion kinase (FAK) becomes tyrosine phosphorylated, and eventually phosphorylates the target proteins. The cooperative effect of integrins and EGF receptor in FAK autophosphorylation at cell spreading on antibody to EGF receptor is discussed.

Antibodies↗

PubMed2004

[alpha-Actinin-4 and p65/RelA subunit of NF-kappaB transcription factor are co-localized and migrate together into the nucleus in EGF-stimulated A431 cell].

The NF-kappaB/Rel family of transcription factors in mammalian cells regulates inducible transcription of a large number of genes in response to diverse stimuli. Despite a great number of publications on this subject, little is known about precise NF-kappaB localization in the cytoplasm. As previously demonstrated, in normal rat fibroblast and human epidermoid carcinoma A431 cells p65/RelA subunit of NF-kappaB is co-localized in the cytoplasm with actin structures. However, the mechanism of NF-kappaB interaction with actin remains unclear. We have investigated localization of p65/RelA subunit NFkappaB and alpha-actinin isoforms during cell activation by epidermal growth factor (EGF). Using confocal microscopy, we have shown that alpha-actinin-4 and p65/RelA subunit of NF-kappaB transcription factor are co-localized in A431 cells. Cell treatment with EGF leads to translocation of the proteins to membrane ruffles, and eventually to migration into the nucleus. Pretreatment of A431 cells with cytochalasin D or wortmannin prior to EGF treatment increases p65/RelA and alpha-actinin-4 accumulation in nuclear extracts. Co-localization of alpha-actinin-4 with p65/RelA subunit of NF-kappaB was found in nuclei isolated from stimulated cells. These results support the notion that actin cytoskeleton reorganization and alpha-actinin-4 are involved in NF-kappaB signaling.

Actinin↗

PubMed2004

[Complex evaluation of wound healing process by a deep wound rat model with implanted polychlorvinyl camera].

A simultaneous study of wound proteolytic activity and morphological picture of the first stages of wound healing on rat deep wound model has been shown. The process of wound healing can be evaluated by dynamics of matrix metalloproteinase activities in wound fluid. Changes in activities of different matrix metalloproteinases correlate with different stages of healing. Implantation of polychlorvinyl camera in the wound makes it possible to obtain the volume of wound fluid sufficient for a complex evaluation of healing at the initial stages of wound process.

Animals↗

PubMed2003

[Effect of burn exudate on functional activity of Balb/3T3 cell line and the role of matrix metalloproteinases in this process].

The influence of burn fluid and its matrix metalloproteinases (MMPs) on Balb/3T3 cells was studied. The influence of burn fluid was assessed by morphology and specific functional activities of cells characteristic of the healing process--proliferation, monolayer contraction and migration of cells in wound model. The presence of burn fluid in cultivating medium accelerated cell proliferation by 2.5 times compared to normal conditions, promoted fibroblast monolayer contraction, and accelerated cell migration on the wound surface, thus stimulating cell functions necessary for successful heating. This effect is partly due to MMPs. The burn fluid contains, presumably, some additional factors not inhibited by specific MMP inhibitors EDTA and 1,10-phenantrolin. These factors may stimulate migration and proliferation of cells. The presence of 1-2% burn fluid is sufficient for enhancing cell proliferation.

3T3 Cells↗