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V V Zenin

Publications and source records attributed to V V Zenin.

At least 19 recordsLinked to original sources
PubMed2006

[Activation of transcriptional factors stat5 and stat3 during human T-lymphocyte proliferation induced by different mitogenic stimuli].

The activation of closely related transcription factors STAT5alpha and STAT5beta is one of the key signalling events during interleukin-2-dependent stage of T-lymphocyte proliferation. Here, we investigate the activation of STAT5 and STAT3 family proteins on different stages of T-cell proliferative response to various mitogenic stimuli. The activation of STAT proteins was estimated according to their tyrosine phosphorylation. Isolated peripheral blood lymphocytes were stimulated by phytogemagglutinin (PHA), or by phorbol-12,13-dibutyrate (PDBu) with calcium ionophore--ionomycin, or by exogenous interleukin-2 (IL-2). After activation of T-cells by PHA as well as by PDBu with ionomycin we observed phosphorylation of STAT5 not earlier than in 5 h. The maximum phosphorylation (by 10 times and more, as compared to control resting lymphocytes) was detected following 24 h of mitogen stimulation. In the lymphocytes pretreated by PHA in submitogenic concentration, exogenous IL-2 induces a proliferative response. High phosphorylation level of STAT5 was determined 10 min after addition of IL-2 and kept for the next 24 h. In contrast to STAT5, some basal phosphorylation of STAT3 was found in resting and PHA-pretreated T-cells. The profile of phosphorylation STAT3 during mitogen-induced activation is more leveled. An immunosuppressant cyclosporine A taken at antiproliferative concentration decreased phosphorylation of both STAT5 and STAT3 by 1.5-2.0 times at early stages, as well as at late stages of activation. A correlation between alteration in tyrosine phosphorylation level of STAT5 and the expression of the high affinity IL-5 receptor was established. Taken together, we report that the increased STAT5 phosphorylation can serve as a marker of T-lymphocyte entrance into IL-2-dependent stage of proliferation after T-cell activation by different mitogens.

Carcinogens↗
PubMed2006

[Participation of bone-marrow stem cells in the differentiation of mdx mice striated muscle].

Two sets of experiments were carried out. The first one involved chimeric mice, obtained by intravenously injections of bone marrow derived cells taken from transgenic C57BL/6 mice, expressing GFP, to 5 Gy X-ray irradiated mdx or C57BL/6 mice. In 2 months M. quadriceps femoris of chimeric mice were destroyed by surgical clamp. Following the next 4-5 weeks, the same muscles were studied for the presence of GFP-positive striated muscle fibres. In the case of chimeric C57BL/6 mice GFP-positive striated muscle fibres were observed in 0.3 +/- 0.5 and in 0.2 +/- 0.3 % of destroyed muscle, and in lateral (control) muscle, consequently. In the case of chimeric mdx mice, positive results were observed in 1.7 +/- 0.4 and in 0.5 +/- 0.3 % of destroyed and control muscles, respectively. In the second set of experiments, the GFP-positive bone marrow cells were used for multiple intramuscular injections to M. quadriceps femoris of C57BL/6 or mdx mice in a dose of 2 x 10(5)-5 x 10(5) cells per mouse. Before injection, GFP-positive bone marrow cells were fractionated in a 63 % Percoll solution and then were exhausted from differentiated cells by magnetic manner using CD4, CD8, CD38, CD45R, CD119, Ly-6G, and F4/80 antibodies. After 2-3 weeks, as many as 0.15 +/- 0.40 and 0.1 +/- 0.2 % of GFP-positive muscle fibres were found in injected and control muscles of C57BL/6 mice, respectively. In the case of mdx mice, the frequency of GFP-positive striated muscle fibres was 2.0 +/- 0.8 and 1.2 +/- 0.6 % for injected and control muscles, respectively. A conclusion is made that bone marrow stem cells can take part in differentiation of mdx mouse muscles after their delivery by needle injections.

Animals↗
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↗
PubMed2003

[Effect of etoposide and amsacrine on mitotic progression of GM-130 and Hep-2 cell lines. The flow cytometry assay].

It has been shown that inhibitors of topoisomerase II (topo II) etoposide and amsacrine results in accumulation of GM-130 and Hep-2 cells with 4c DNA amount. The differential analysis based on flow cytometry (Zenin et al., 2001) and enabled us to discriminate cells with 4c DNA--G2, M, including metaphase and anaphase cells and cells in pseudo-G1. 1 microM etoposide evoked cell accumulation in G2 phase, while 40 microM etoposide blocked cell proliferation, which was confirmed by a complete absence of both mitotic cells and 4c DNA cell accumulation. GM-130 and Hep-2 cells that were first blocked and then washed from nocodazole, and after that treated with 50 microM etoposide or 20 microM amsacrine, were shown to enter pseudo-G1 with 4c DNA amount per cell. In the presence of nocodazole, 4 and 40 microM amsacrine evoked transition of all mitotic cells to pseudo-G1 within 1 h. 15 or 30 minutes pulse treatments of GM-130 cells with 40 microM amsacrine in the presence of nocodazole, followed by incubation in drug-free medium, resulted in the similar transition of cells to pseudo-G1.

Amsacrine↗
PubMed2003

[Isolation and characterisation of continuous human embryonic stem cell lines].

A long-term cultivation (5-8 months) of human blastocyst-derived embryonic cells (hES) was performed. Several properties of hESs were examined to prove the state of continuous cell lines. These cells have passed through 100-175 population doublings with the average population doubling time equal to 37.0 +/- 1.5 h. Isolated hESs, referred to as HESC-1, HESC-2, HESC-3, HESC-4, cultivated on mitotically inactivated mouse embryonic fibroblasts (STO continuous cell line), formed multilayer colonies of various shape. The cells maintained stable proliferative activity, high activity of alkaline phosphatase and expression of transcription factor Oct4, and all this characterizes embryonic stem cells of different origin. Expression of hES specific cell surface antigens (SSEA-3, SSEA-4, TRA-1-81 and TRA-11-81 and TRA-1-60) was confirmed by immunofluorescence analysis with the corresponding monoclonal antibodies. An additional prove for species specificity of HESC lines is the lack of expression of mouse specific surface antigen SSEA1. The cell cycle of HESC-1 undifferentiated cells and embryoid bodies was analysed cytofluorimetrically.

Alkaline Phosphatase↗
PubMed2002

[Flow cytometric analysis of ICRF-193 influence on cell passage through mitosis].

Studying the effect of topoisomerase II (topo II) inhibitors on cell passage through mitosis seems to be important for understanding the role of this enzyme during chromosome condensation and segregation. A flow cytometric assay (Zenin et al., 2001) allowed to determine the mitotic index, and to discriminate between not only cells in G2 and M phases (including metaphase and anaphase cells), but also cells in pseudo-G1 with 4c DNA content. It is shown that topo II catalytic inhibitor ICRF-193 blocks G2-M transition in a lymphoblastoid cell line GM-130. Addition of caffeine to cells abrogated a block of their entering mitosis but not the inhibitor action. Cells entered mitosis, which was proven by the presence of chromosomes in the examined specimen, and, bypassing anaphase, appeared in pseudo-G1 with 4c DNA content. We have found that in the presence of ICRF-193 cells, GM-130 and Hep-2 lines, previously blocked by nocodazole when in mitosis and then washed, pass through metaphase, enter anaphase and leave it to pass to pseudo-G1 with the 4c DNA content. Thus, by inhibiting topo II activity ICRF-193 causes abnormal mitotic transition.

Caffeine↗
PubMed1997

[The immunomodulating and immunoprotective activity of small ribonucleoprotein complexes (alpha RNPs) from the LRec-1sf cell line].

Effect of nuclear and released into culture medium alpha RNPs (N- and R-alpha-RNPs, resp.) produced by transformed rat embryo fibroblasts of serum-free cell line LRec-1sf on the nonsensibilized mouse splenocyte cytotoxicity (NK-mediated cell lysis) was studied. A preliminary treatment with N-alpha-RNPs resulted in decreasing K562 cell sensitivity to splenocyte cytotoxicity, whereas pretreatment of the splenocytes themselves exerted no cytotoxic effect. The target cell preincubation with R-alpha-RNPs had no influence on K562 cell resistance to NK cell cytotoxicity. The identical splenocyte preincubation was without action on their cytotoxic effect to LRec-1sf cells, however, resulted in an increase of the K562 cell lysis. The addition of R-alpha-RNPs into splenocyte/target cell mixtures had no influence on NK-mediated lysis, when K562 cells were used as a target cell line, but suppressed the NK-mediated lysis of LRec-1sf cells. The results of the present experiments suggest that alpha RNPs produced by LRec-1sf cell line exhibit the capacity for modulating both mouse NK cytotoxicity, and the transformed cell sensitivity to NK-mediated lysis.

Adjuvants, Immunologic↗
PubMed1996

[The use of lysolecithin for obtaining a chromosome suspension].

Lysolecithin treatment was used for obtaining isolated metaphase chromosomes from HeLa cells and lymphoblastoid cell lines BOLD and ROM. Chromosomes were stained with Hoechst 33258 and olivomycine. Chromosome quantity in suspension was determined by dual-laser sorter ATC-3000. It is shown that lysolecithin treatment of the cells allows to isolate chromosomes with higher concentration in suspension and less amount of debris in comparison with Triton X-100 treatment. A protocol for chromosome isolation using lysolecithin treatment is suggested.

Cell Fractionation↗
PubMed1996

[The physical mapping of human chromosomes. II. The production of unique chromosome-specific DNA fragments using the polymerase chain reaction with oligonucleotide primers to conservative regions of Alu repeats].

Unique DNA fragments localised between Alu-repeats have been produced by PCR. The reaction was carried out with oligonucleotide primers to conservative regions of Alu-repeats. The DNA fragments from different pulls, individual clones, chromosome-specific clonotecs derived from phage lambda, cosmids and individual human chromosomes served as matrixes. The possibilities are discussed of Alu-primer applying in production of exceptional physical features of DNA molecules, suitable for constructing clone couple groups and for direct physical mapping on the DNA of isolated chromosomes, missing the stage of cloning.

Base Sequence↗
PubMed1994

[Chromosome fractionation in a saccharose density gradient for subsequent flow sorting].

The human chromosomes were obtained from lymphoblastoid cell line BOLD with normal karyotype, and separated on the basis of their size by velocity sedimentation at 190 g in sucrose gradient. Different chromosomal fractions were stained by applying fluorochromes with different DNA-base specificity: Hoechst 33258 and Olivomycine and were analysed using dual laser cell-sorter ATC-3000 (Brucker). Velocity sedimentation allowed to enrich certain fractions by individual chromosomes and thus speed up the sorting rate from 90 up to 200 chromosomes per second.

Cell Fractionation↗
PubMed1992

Drop-delay measurement using enzyme-coated particles.

A simple technique is suggested for the measurement of drop delay for flow sorting. While the flow cytometer was set to sort a fixed number of particles, the drop-delay setting was changed step by step, and at each step the HRP-coupled particles were sorted into a well of an immunoassay strip. Then the HRP activity of the sorted samples was revealed by routine methods. The maximum level of the enzyme activity shows the proper drop-delay setting. Determination of the drop-delay setting takes only a few minutes. The technique is independent of the type of flow cytometer and does not require any additional equipment.

Animals↗
PubMed1991

Reversible G2 block in the cell cycle of Ehrlich ascites carcinoma cells.

Using flow cytometry we found that proliferation of Ehrlich ascites carcinoma (EAC) cells has been reversibly arrested in the second half of the G2 period at the plateau phase of tumor growth in vivo. The ratio of G2/G1 cells increased from 0.3 at 6 days post tumor inoculation to 2.5 at 16 days when up to 25-35% of EAC cells are in G2. It was shown that when ascites fluid removal was followed by transferral in culture, G2-blocked cells synchronously entered the G1 phase via mitosis. In the presence of ascites fluid in the culture medium, EAC cells progressed through G1 and S phases but accumulated in G2. Fetal bovine serum, beta-mercaptoethanol, and caffeine failed to release cells from the G2 block when added to ascites fluid in culture. It is concluded that neither nutrient depletion nor a lack of growth factors is responsible for the G2 arrest of EAC cells. We suggest that ascites fluid contains a factor(s) which potently interrupts the G2 phase of the cell cycle.

Animals↗
PubMed1987

[Effect of amines on the binding, internalization and degradation of epidermal growth factor and the induction of DNA synthesis in a 3T3 cell culture].

The role of intracellular processing of epidermal growth factor (EGF) in the induction of proliferation of quiescent Swiss 3T3 cells was studied using various inhibitors. The number of amines (dansylcadaverine, chloroquine, cystamine, 5-methoxytryptamine) dimethylurea and monensin were shown to block the mitogenic effect of EGF. The majority of these substances while used in concentrations sufficient to inhibit the proliferation do not significantly influence 125I-EGF binding and internalization. The level of EGF degradation was reduced only by chloroquine. The inhibitory effect of amines and monensin on the generation of proliferative signal was supposed to take place at the stages of EGF processing in "specialized" endosomes and in Golgi apparatus.

Amines↗
PubMed1985

[Flow fluorimetry of the cellular DNA of the bone marrow in normal mice and after exposure to extreme factors].

The distribution of murine bone marrow cells in regard to cell cycle was examined using flow cytometry technique. In normal NIH mice the percentage of cells being into phases G1/0, S and G2 + M constitutes 78, 15 and 7%, respectively. In mice subjected to X-irradiation (2, 12 Gy), the thermal burn, and X-irradiation plus the burn the proportion of G2 + M-cells increased, which may be presumably due to their delay on stage G2 of the cell cycle. The start and duration of the delay in the G2 phase depend upon the kind of damage applied.

Animals↗
PubMed1984

[Rapid method for the intravital assessment of proliferative activity in monolayer cultures].

A simple and quick method is proposed for measuring the mitotic activity in monolayer cell cultures. The method is based on counts of mitotic figures in several microscopic fields without fixing and staining the cells. The counting procedure takes little time, and culture dishes (or flasks) may be then used for other experiments. The proliferation activity of Swiss 3T3 cells was estimated by this technique and compared with the results provided by the flow cytofluorimetric analysis.

Animals↗
PubMed1984

[Effect of cultivation conditions on the growth properties of Swiss 3T3 cells].

A possibility of using Swiss 3T3 cells, adapted to the growth in the Eagle basal medium and bovine serum, in studies of cell proliferation and quiescent state was shown on the basis of their growth characteristics. Proliferative activity of cultures was estimated by measuring the intensity of DNA synthesis (incorporation of labeled thymidine and flow cytofluorometric analysis), mitotic index and cell number counts. Growth rate and saturation density of the culture were analyzed depending on serum concentration, substrate quality and medium changes both in growth and quiescent states. In spite of repeated medium changes such adapted cells had saturation density within 4.10(4)--7.10(4) cells/cm2, standard for this line. Besides, a distinct inhibition of cell proliferation at confluence or after incubation with low serum (0.5%) and a possibility of the following stimulation of cell divisions by adding a fresh medium containing different concentrations of serum were demonstrated. The increased rate of adipose conversion was detected in resting confluent 3T3 cells cultivated in closed vessels, as compared to cells growing in tissue culture dishes in the CO2 incubator.

Animals↗
PubMed1983

[Intraclonal and interclonal differences of ploidy in transplantable rat rhabdomyosarcoma RA-2 detected using DNA flow cytometry].

DNA contents were determined using flow cytometry in cells of 71 clones of the rat transplantable rhabdomyosarcoma passed through more than 70 cycles of selection for increased malignancy. 58 clones (82%) consisted of cells with diploid DNA content, whereas 13 clones (18%) displayed not only diploid, but also near tetraploid cell subpopulations, the latter covering from 20 to 60% of the total number of cells measured. The data obtained show the existence of intra- and interclonal karyotypic heterogeneity in populations of tumor clonogenic cells.

Animals↗