scholarly journals Change of cytokeratin filament organization during the cell cycle: selective masking of an immunologic determinant in interphase PtK2 cells.

1983 ◽  
Vol 97 (4) ◽  
pp. 1255-1260 ◽  
Author(s):  
W W Franke ◽  
E Schmid ◽  
J Wellsteed ◽  
C Grund ◽  
O Gigi ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Monoclonal Antibody ◽  
Cell Cultures ◽  
Immunofluorescence Microscopy ◽  
Specific Reaction ◽  
Low Concentrations ◽  
Interphase Cells ◽  
Triton X ◽  
Cytokeratin Filaments ◽  
Striking Contrast

The organization of intermediate-sized filaments (IF) of the cytokeratin type was studied in cultures of PtK2 cells in which typical IF structures are maintained during mitosis, using a monoclonal antibody (KG 8.13). This antibody reacts, in immunoblotting experiments, with the larger of the two major cytokeratin polypeptides present in these cells but, using standard immunofluorescence microscopy procedures, does not react with the cytokeratin filaments abundant in interphase cells, in striking contrast to various antisera and other monoclonal cytokeratin antibodies. In the same cell cultures, however, the antibody does react with cytokeratin filaments of mitotic and early postmitotic cells. The specific reaction with cytokeratin filaments of mitotic cells only is due to the exposure of the specific immunologic determinant in mitosis and its masking in interphase cells. Treatment of interphase cells with both Triton X-100 as well as with methanol and acetone alters the cytokeratin filaments and allows them to react with this monoclonal antibody. A similar unmasking was noted after treatment with buffer containing 2 M urea or low concentrations of trypsin. We conclude that the organization of cytokeratin, albeit still arranged in typical IF, is altered during mitosis of PtK2 cells.

Cell cycle-dependent reactivity with the monoclonal antibody Ki-67 during myeloid cell differentiation

1988 ◽  
Vol 179 (1) ◽  
pp. 79-88 ◽  
Author(s):  
Robert P. Wersto ◽  
Fritz Herz ◽  
Robert E. Gallagher ◽  
Leopold G. Koss
Keyword(s):  
Cell Cycle ◽  
Monoclonal Antibody ◽  
Cell Differentiation ◽  
Myeloid Cell ◽  
Ki 67 ◽  
Cycle Dependent

Hepatoma Cell Cultures as In Vitro Models for the Hepatotoxicity of Xenobiotics

1988 ◽  
Vol 16 (1) ◽  
pp. 32-37
Author(s):  
Margherita Ferro ◽  
Anna Maria Bassi ◽  
Giorgio Nanni
Keyword(s):  
Cell Lines ◽  
Cell Cultures ◽  
Membrane Lipids ◽  
Hepatoma Cell ◽  
Positive Control ◽  
In Vitro Models ◽  
Low Concentrations ◽  
Formation Efficiency ◽  
Dose Dependent

Two hepatoma cell cultures were examined as in vitro models to be used in genotoxicity and cytotoxicity tests without the addition of bioactivating enzymes. The MH1C1, and HTC hepatoma lines were used in this study to establish their sensitivity to a number of xenobiotics, namely, cyclophosphamide (CP), the classical positive control in bioactivation tests; benzaldehyde (BA), a short-chain aldehyde; and 4-hydroxynonenal (HNE), a major toxic end-product of the peroxidative degradation of cell membrane lipids. As a first approach, we compared the following cytotoxicity tests: release of lactate dehydrogenase (LDH), and colony formation efficiency (CF). Colony-forming cells were exposed to the drugs according to different procedures, before or after the anchorage phase. The leakage of LDH into the medium following exposure of both cell lines to HNE, CP and BA for up to 24 hours was found not to be a good index of cytotoxicity. A better indicator of cytotoxicity was CF, as evaluated by exposure of the cells 24 hours after seeding. The effects were detectable at very low concentrations, corresponding to 10, 90 and 100μM for HNE, CP and BA, respectively. The impairment of CF efficiency was dose-dependent and time-dependent, and several differences between the two cell lines were observed.

scholarly journals NAC, Tiron and Trolox Impair Survival of Cell Cultures Containing Glioblastoma Tumorigenic Initiating Cells by Inhibition of Cell Cycle Progression

PLoS ONE ◽  
2014 ◽  
Vol 9 (2) ◽  
pp. e90085 ◽  
Author(s):  
Massimiliano Monticone ◽  
Razieh Taherian ◽  
Sara Stigliani ◽  
Elisa Carra ◽  
Stefano Monteghirfo ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Cultures ◽  
Cell Cycle Progression ◽  
Cycle Progression

scholarly journals Cell cycle analysis of primary sponge cell cultures

2011 ◽  
Vol 47 (4) ◽  
pp. 302-311 ◽  
Author(s):  
Klaske J. Schippers ◽  
Dirk E. Martens ◽  
Shirley A. Pomponi ◽  
René H. Wijffels
Keyword(s):  
Cell Cycle ◽  
Cell Cultures ◽  
Cell Cycle Analysis ◽  
Sponge Cell

Cell cycle controls and the role of nerves and the regenerate epithelium in urodele forelimb regeneration: possible modifications of basic concepts

1987 ◽  
Vol 65 (8) ◽  
pp. 739-749 ◽  
Author(s):  
Roy A. Tassava ◽  
David J. Goldhamer ◽  
Bruce L. Tomlinson
Keyword(s):  
Cell Cycle ◽  
Monoclonal Antibody ◽  
Limb Regeneration ◽  
Blastema Formation ◽  
Basic Concepts ◽  
Regenerate Epithelium ◽  
Early Wound ◽  
Skin Epidermis ◽  
Wound Epithelium

Data from pulse and continuous labeling with [3H]thymidine and from studies with monoclonal antibody WE3 have led to the modification of existing models and established concepts pertinent to understanding limb regeneration. Not all cells of the adult newt blastema are randomly distributed and actively progressing through the cell cycle. Instead, many cells are in a position that we have designated transient quiescence (TQ) and are not actively cycling. We postulate that cells regularly leave the TQ population and enter the actively cycling population and vice versa. The size of the TQ population may be at least partly determined by the quantity of limb innervation. Larval Ambystoma may have only a small or nonexisting TQ, thus accounting for their rapid rate of regeneration. Examination of reactivity of monoclonal antibody WE3 suggests that the early wound epithelium, which is derived from skin epidermis, is later replaced by cells from skin glands concomitant with blastema formation. WE3 provides a useful tool to further investigate the regenerate epithelium.

Initiation and morphological development of somatic embryoids from barley cell cultures

1984 ◽  
Vol 62 (6) ◽  
pp. 1245-1249 ◽  
Author(s):  
L. S. Kott ◽  
K. J. Kasha
Keyword(s):  
Somatic Embryogenesis ◽  
Abscisic Acid ◽  
Gibberellic Acid ◽  
Cell Cultures ◽  
Dichlorophenoxyacetic Acid ◽  
Morphological Development ◽  
Low Concentrations ◽  
The Media ◽  
2,4 Dichlorophenoxyacetic Acid ◽  
Barley Cell

Somatic embryogenesis was induced in callus previously initiated from immature embryos of barley. These cultures ranged in age from 6 weeks to 30 months. Embryoids were readily initiated from homogenized suspension-grown aggregates when plated on modified B5 media with 2,4-dichlorophenoxyacetic acid. Low concentrations (0.1 and 0.05 mg∙L−1) of abscisic acid promoted further maturation of embryoids, while gibberellic acid (1 mg∙L−1) and kinetin (0.1 mg∙L−1) were used in the media to encourage embryoid germination. The development of somatic embryoids from initiation through maturation and germination is described.

scholarly journals The roles of phospholipase D and a GTP-binding protein in guanosine 5′-[γ-thio]triphosphate-stimulated hydrolysis of phosphatidylcholine in rat liver plasma membranes

1990 ◽  
Vol 272 (3) ◽  
pp. 749-753 ◽  
Author(s):  
K M Hurst ◽  
B P Hughes ◽  
G J Barritt
Keyword(s):  
Rat Liver ◽  
Phospholipase D ◽  
Plasma Membranes ◽  
Regulatory Protein ◽  
Gtp Binding ◽  
Liver Plasma Membranes ◽  
Low Concentrations ◽  
Rat Liver Plasma Membranes ◽  
Triton X ◽  
Hydrolysis Of

1. Guanosine 5′-[gamma-thio]triphosphate (GTP[S]) stimulated by 50% the rate of release of [3H]choline and [3H]phosphorylcholine in rat liver plasma membranes labelled with [3H]choline. About 70% of the radioactivity released in the presence of GTP[S] was [3H]choline and 30% was [3H]phosphorylcholine. 2. The hydrolysis of phosphorylcholine to choline and the conversion of choline to phosphorylcholine did not contribute to the formation of [3H]choline and [3H]phosphorylcholine respectively. 3. The release of [3H]choline from membranes was inhibited by low concentrations of SDS or Triton X-100. Considerably higher concentrations of the detergents were required to inhibit the release of [3H]phosphorylcholine. 4. Guanosine 5′-[beta gamma-imido]triphosphate and guanosine 5′-[alpha beta-methylene]triphosphate, but not adenosine 5′-[gamma-thio]-triphosphate, stimulated [3H]choline release to the same extent as did GTP[S]. The GTP[S]-stimulated [3H]choline release was inhibited by guanosine 5′-[beta-thio]diphosphate, GDP and GTP but not by GMP. 5. It is concluded that, in rat liver plasma membranes, (a) GTP[S]-stimulated hydrolysis of phosphatidylcholine is catalysed predominantly by phospholipase D with some contribution from phospholipase C, and (b) the stimulation of phosphatidylcholine hydrolysis by GTP[s] occurs via a GTP-binding regulatory protein.

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