Paracrine senescence of human endometrial mesenchymal stem cells: a role for the insulin-like growth factor binding protein 3.

Stress-induced premature cell senescence is well recognized to be accompanied by emerging the senescence-associated secretory phenotype (SASP). Secreted SASP factors can promote the senescence of normal neighboring cells through autocrine/paracrine pathways and regulate the senescence response, as well. Regarding human endometrium-derived mesenchymal stem cells (MESCs), the SASP regulation mechanisms as well as paracrine activity of senescent cells have not been studied yet.

Senescence-messaging secretome factors trigger premature senescence in human endometrium-derived stem cells.

Accumulating evidence suggests that the senescence-messaging secretome (SMS) factors released by senescent cells play a key role in cellular senescence and physiological aging. Phenomenon of the senescence induction in human endometrium-derived mesenchymal stem cells (MESCs) in response to SMS factors has not yet been described. In present study, we examine a hypothesis whether the conditioned medium from senescent cells (CM-old) may promote premature senescence of young MESCs.

COMPARISON OF THE SHAPE OF RABBIT MESENCHYMAL STROMAL CELLS DURING FIVE PASSAGES AFTER PRODUCTION OF PRIMARY CULTURE.

Cultivation of cells under artificial conditions is one of the necessary procedures when working with stem cells. At this stage, the cells lose control by the macroorganism, becoming independent systems. Therefore, during the passaging of the cells, the probability of undesirable modifications is increased.

[MORPHOLOGY OF NCTC CELLS ONE DAY AFTER RESEEDING].

Development of regenerative medicine based on the use of stem cells is substantially dependent on the prediction of the changes that the cells undergo after culturing them in vitro. Therefore, the accumulation of knowledge in the field, which can be denoted as biology of cells in culture, is of special importance. Features of functioning cells in vitro is better to study in the permanent cells lines as their morphological and functional characteristics in numerous passages can be regarded as the result of adaptation of cells to grow outside the body.

[SPREADING OF NCTC CLONE 929 CELLS AFTER RESEEDING].

The period (1 h after reseeding) of behaviour of mouse NCTC clone 929 cells to the conditions of artificial cultivation was studied. The time-lapse imaging followed the processing of the cells with ImageJ program was applied. To characterize the parametres cell status we used the cell area (projection of the cell on substrate) and Rp/Ra ratio introduced earlier as a spreading coefficient (Kuz'minykh, Petrov, 2004).

[Morphology of NCTC cells upon a contact with type I collagen added to culture medium].

The morphometric characteristics of NCTC cells upon their contact with type I collagen added to culture medium were studied. The cells were plated on plastic in the colony form. In a day after seeding, the culture medium was changed for the same medium complemented with 0.

[Colocalization of nucleoli in cell nuclei of HeLa line].

The pattern of localization of nucleoli relative to each other and to cell nucleus was studied in M-HeLa cell line. For this puspose, the following morphometric parameters were introduced. For the two-nucleolar cells: 1) the ratio of the nucleus long axis to the length of a segment between the centers of the nucleoli, and 2) the angle between the segment connecting the centers of the nucleoli and a longitudinal axis of cell nucleus.

[Response of HeLa cells to mitomycine C. III. The analysis of nucleoli of mother and daughter cells].

The comparative analysis of the number of nucleoli in cells of the established HeLa-M line was carried out before and after exposure to mitomycin C in a concentration of 10 μg/ml for 2 h. Using time-lapse microscopy, nucleoli in mother and their respective daughter cells were computed. It has been shown that the average number of nucleoli per cell is generally higher in daughter cells than in mother cells, and a standard deviation, on the contrary, decreases.

[Growth features of CHO cells in culture].

Dependence of growth characteristics of cell population and the monolayer formation on the initial plating concentrations of cells were studied on the established CHO cell line. The cells were cultivated under standard conditions on plastic substrate. Initial plating concentration was varied as: 1000, 2000, 3000, 4000, 5000, and 6000 cell/cm2.

[Response of HeLa cells to mitomycine C. II. Morphometry of the cells].

HeLa-M cells were analyzed after the 2h incubation in the medium with mitomycin C (10 μg/ml). It has been shown that a part of the cells contacted with the cytostatic agent passes mitosis normally, but the daughter cells no longer divide. During the observation period (2 days), the area of the cells increased linearly reaching twice the size of intact cells.

[Vital measurement of optical density of HeLa cell line].

Light absorption by the live intact HeLa cells during light microscopy was studied. The light absorption may be considered as a parameter analogous to optical density used in spectrophotometry. This parameter can be used as a quantitative characteristic of life cell as well as intracellular structures.

[The estimation of similarity in characteristics of the post-mitotic daughter L-929 cells during their migration along the substrate].

Using time-lapse microscopy, spreading of the post-mitotic daughter cells has been studied. The work was performed on non-synchronized cells of established L-929 cell line. The study was aimed to characterize the morphology of the cells as they move along the substrate and to determine whether the area of the migrating cells changes nonrandom.

[Dynamics of spreading of cells of L-929 line after the mitosis].

Using time-lapse microscopy, the changes in L-929 cells shape were analyzed during a cell cycle. During this time the cells were established to pass through three spreading stages. The highest rate of the cell spreading was observed during the first 1.

[Analysis of the cell cycle duration of cells of permanent line L-929].

The direct measurement of the cell cycle duration in L-929 cells was performed using time-lapse photography. The cell cycle duration was 15.77 +/- 0.

[The position of cleavage furrow in cultivated cells on the example of lines L-929 and CHO].

The aim of the study carried out on cells of lines L-929 (NCTC a clone 929) and CHO was to examine whether the position of cleavage furrow is random or not. CHO cells were seeded in the traditional way (evenly across the surface of a Petri dish), and L-cell were put as colonies to monitor the migration of cells emanating from them. The time-lapse filming (imaging) was used for registration of behavior of cells.

Extracellular HspBP1 and Hsp72 synergistically activate epidermal growth factor receptor.

Background Information: Heat-inducible Hsp72 is the founding member of the Hsp70 (heat shock proteins of 70 kDa) family of molecular chaperones. It is localized primarily in cytoplasm and nucleus but is also found extracellularly. The source of e-Hsp72 (extracellular Hsp72) is not precisely identified and may not be the same in every situation.

[The influence of transplanted culture of bone marrow stromal cells on reparative osteohistogenesis in parietal bone defect].

Recently the problem connected with transplantation of bone marrow stromal cells for optimization of reparative osteogenesis is very actively studied. However, the objective methods allowing to observe the behavior of transplanted cells in a bone wound and to estimate character of regenerative osteogenesis after cell transplantation are used in an insufficient measure in both experimental and clinical researches. The aim of this study is to clarify the fate of stromal cells in a bone wound and to investigate the influence of bone marrow stromal cells on the process ofposttraumatic osteogenesis after cell transplantation in parietal bone defect.

[EGF-dependent signaling pathways are activated under heat stress in A431 carcinoma cells].

EGF receptor transactivation and activation of EGF-dependent signaling pathways under heat shock conditions were studied. Heating A431 cells at 42 degrees C induced both EGF receptor tyrosine phosphorylation and appearance of phosphorylated forms of key components of its downstream signaling pathways - phospholipase Cgamma1 (PLCgamma1), transcription factor STAT3, and EPK1/2. It is suggested that EGF receptor is transactivated under heat shock in A431 cells.

[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.

[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.

[Effect of EGF on the intracellular distribution of heat-shock proteins in A431 cells].

The intracellular distribution of hsp70 and hdj1 was studied using immunofluorescent method. In nonstimulated cells hsp70 and hdj1 were observed in the cytoplasm of A431 cells. When 100 ng/ml EGF was added for 15 min, both hsp70 and hdj1 were accumulated in the nuclei.

[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.

[Effect of EGF on ubiquitination and proteasome-dependent degradation of phospholipase C gamma1 in A431 cells].

Phospholipase C gamma 1 (PLC gamma 1), an enzyme participating in phosphoinositide turnover, is one of the key elements in cell signaling. Here it is shown that treatment of A431 carcinoma cells with proteasome inhibitors Mg132 and lactacystin results in increasing the PLC gamma 1 intracellular level. Simultaneously, several additional bands with lower electrophoretic mobilities were detected on immunoblots, using anti-PLC gamma 1 antibodies.