scholarly journals The role of extracellular materials in cell movement. I. Inhibition of mucopolysaccharide synthesis does not stop ruffling membrane activity or cell movement.

1975 ◽  
Vol 65 (2) ◽  
pp. 286-297 ◽  
Author(s):  
B S Spooner ◽  
G W Conrad
Keyword(s):  
Cytochalasin B ◽  
Cell Movement ◽  
Embryonic Heart ◽  
Membrane Activity ◽  
Cell Locomotion ◽  
Extracellular Materials

The involvement of mucopolysaccharide synthesis in cell locomotion was investigated by determining the effects of inhibition of synthesis on ruffling membrane activity and cell movement by embryonic heart fibroblasts. Mucopolysaccharide synthesis was inhibited directly by treatment with a glutamine analog, 6-diazo-5-OXO-L-norleucine (DON), and indirectly with cycloheximide. DON treatment reduced synthesis to 20% of control values, and cycloheximide reduced synthesis to less than 10% of control values, as measured by incorporation of [35S]sulfate into mucopolysaccharides. Nevertheless, ruffling membrane activity and cell locomotion continued under both conditions. Cytochalasin B did not inhibit mucopolysaccharide synthesis, although it did stop ruffling and locomotion. These results suggest that if mucopolysaccharides are required for cell movement, they must have long half-lives or represent only a minute fraction of the normal synthetic load.

scholarly journals MICROFILAMENTS AND CELL LOCOMOTION

1971 ◽  
Vol 49 (3) ◽  
pp. 595-613 ◽  
Author(s):  
Brian S. Spooner ◽  
Kenneth M. Yamada ◽  
Norman K. Wessells
Keyword(s):  
Protein Synthesis ◽  
Plasma Membrane ◽  
Cytochalasin B ◽  
Cell Movement ◽  
Leading Edge ◽  
Complete Recovery ◽  
Cell Locomotion ◽  
Cell Processes

The role of microfilaments in generating cell locomotion has been investigated in glial cells migrating in vitro. Such cells are found to contain two types of microfilament systems: First, a sheath of 50–70-A in diameter filaments is present in the cytoplasm at the base of the cells, just inside the plasma membrane, and in cell processes. Second, a network of 50-A in diameter filaments is found just beneath the plasma membrane at the leading edge (undulating membrane locomotory organelle) and along the sides of the cell. The drug, cytochalasin B, causes a rapid cessation of migration and a disruption of the microfilament network. Other organelles, including the microfilament sheath and microtubules, are unaltered by the drug, and protein synthesis is not inhibited. Removal of cytochalasin results in complete recovery of migratory capabilities, even in the absence of virtually all protein synthesis. Colchicine, at levels sufficient to disrupt all microtubules, has no effect on undulating membrane activity, on net cell movement, or on microfilament integrity. The microfilament network is, therefore, indispensable for locomotion.

scholarly journals LIGAND-INDUCED MOVEMENT OF LYMPHOCYTE MEMBRANE MACROMOLECULES

1974 ◽  
Vol 140 (5) ◽  
pp. 1207-1220 ◽  
Author(s):  
Emil R. Unanue ◽  
Morris J. Karnovsky
Keyword(s):  
B Lymphocytes ◽  
Cytochalasin B ◽  
Posterior Part ◽  
Cell Movement ◽  
The Other ◽  
Con A ◽  
Translational Movement ◽  
Membrane Perturbation ◽  
Energy Dependent

Capping of surface Ig by anti-Ig antibodies involves a membrane perturbation requiring an energy-dependent step. Lymphocytes treated with anti-Ig are stimulated to move. Previously, we had shown that movement was not essential for capping, although it influenced the localization of the cap. We have investigated the role of cell movement and of microtubular proteins in this phenomenon. Treatment of B lymphocytes with colchicine does not affect capping of Ig nor does it affect the increase in translational movement produced by anti-Ig antibodies. Treatment of lymphocytes with cytochalasin B stops translational movement and may affect capping to some degree under appropriate circumstances. Lymphocytes treated with both drugs are impaired in capping. We surmise that there may be two cytoplasmic events regulating directly or indirectly capping: one associated with the process of translational movement, the other associated with the activity of microtubules. Lymphocytes treated with concanavalin A do not cap Ig. Colchicine reverses this inhibition. Certain experimental procedures antagonize the colchicine effect, the most striking of which is the use of cytochalasin B. Colchicine appears to increase movement of the Con A-treated lymphocyte, and this increased movement appears responsible for the accumulation of complexes to the posterior part of the cell. Con A inhibits patching of Ig by anti-Ig, and this is not reversed by colchicine.

Current Study of RhoA and Associated Signaling Pathways in Gastric Cancer

2020 ◽  
Vol 15 (7) ◽  
pp. 607-613 ◽  
Author(s):  
Haiping Liu ◽  
Yiqian Liu ◽  
Xiaochuan Zhang ◽  
Xiaodong Wang
Keyword(s):  
Gastric Cancer ◽  
Survival Rate ◽  
Signaling Pathways ◽  
Tumor Cells ◽  
Actin Polymerization ◽  
Cell Transformation ◽  
Cell Movement ◽  
Invasion And Metastasis ◽  
Common Cancer

Gastric cancer (GC) is the fourth-most common cancer in the world, with an estimated 1.034 million new cases in 2015, and the third-highest cause of cancer deaths, estimated at 785,558, in 2014. Early diagnosis and treatment greatly affect the survival rate in patients with GC: the 5‐year survival rate of early GC reaches 90%‐95%, while the mortality rate significantly increases if GC develops to the late stage. Recently, studies for the role of RhoA in the diseases have become a hot topic, especially in the development of tumors. A study found that RhoA can regulate actin polymerization, cell adhesion, motor-myosin, cell transformation, and the ability to participate in the activities of cell movement, proliferation, migration, which are closely related to the invasion and metastasis of tumor cells. However, the specific role of RhoA in tumor cells remains to be studied. Therefore, our current study aimed to briefly review the role of RhoA in GC, especially for its associated signaling pathways involved in the GC progression.

scholarly journals The role of phosphotransferases in the respiratory control of the embryonic heart

1963 ◽  
Vol 169 (4) ◽  
pp. 799-815 ◽  
Author(s):  
Sara Eisenberg ◽  
J. Ramirez
Keyword(s):  
Respiratory Control ◽  
Embryonic Heart

scholarly journals Role of divalent cations, pH, cytoskeleton componentes and surface charge on the adhesion of Trichomonas vaginalis to a polystyrene substrate

1987 ◽  
Vol 82 (3) ◽  
pp. 379-384 ◽  
Author(s):  
Fernando Costa e Silva Filho ◽  
Cezar Antonio Elias ◽  
Wanderley de Souza
Keyword(s):  
Surface Charge ◽  
Incubation Time ◽  
Trichomonas Vaginalis ◽  
Cytochalasin B ◽  
Culture Media ◽  
Divalent Cations ◽  
Polystyrene Beads ◽  
Different Strains ◽  
Adhesion Index

The process of adhesion of three different strains of Trichomonas vaginalis to a polystyrene substrate was analysed. The process of adhesion was dependent on the time of incubation and the pH of the phosphate-buffered solution (PBS) in which the parasites were suspended. The highest indices of adhesion were observed after an incubation time of 60 min at pH 6.6. The adhesion index increased when the parasites were incubated in the presence of culture media or when Ca++ or Mg++ was added to the PBS solution, whereas cytochalasin B, trypsin or neuraminidase reduced adhesion. Incubation of the parasites in the presence of poly-L-lysine facilitated the process of adhesion. Incubation of the parasites or polystyrene beads in the presence of poly-L-lysine led to important changes in their surface charge.

The role of initial cells in maize anther morphogenesis

Development ◽  
1992 ◽  
Vol 116 (4) ◽  
pp. 1077-1085 ◽  
Author(s):  
R.K. Dawe ◽  
M. Freeling
Keyword(s):  
Cell Division ◽  
Small Groups ◽  
Cell Movement ◽  
Basic Structure ◽  
Early Growth ◽  
Structural Template ◽  
Axes Of Symmetry ◽  
The Relationship ◽  
Mature Anther

The near absence of cell movement in plants makes clonal analysis a particularly informative method for reconstructing the early events of organ formation. We traced the patterns of cell division during maize anther development by inducing sector boundaries that preceded the earliest events of anther initiation. In doing this, we were able to estimate the smallest number of cells that are fated to form an anther, characteristic cell division patterns that occur during anther morphogenesis, and the relationship between the pre-existing symmetry of the initial cells and the final symmetry of the mature anther. Four general conclusions are made: (1) anthers are initiated from small groups of 12 or fewer cells in each of two floral meristematic layers; (2) the early growth of the anther is more like a shoot than a glume or leaf; (3) cell ancestry does not dictate basic structure and (4) the orientation of initial cells predicts the orientation of the four pollen-containing microsporangia, which define the axes of symmetry on the mature anther. The final point is discussed with other data, and an explanation involving a ‘structural template’ is invoked. The idea is that the orientation of initial cells within the floral meristem establishes an architectural pattern into which anther cells are recruited without regard to their cellular lineages. The structural template hypothesis may prove to be generally applicable to problems of pattern formation in plants.

Some clues as to the formation of protrusions by Fundulus deep cells

1977 ◽  
Vol 26 (1) ◽  
pp. 139-150
Author(s):  
C. Tickle ◽  
J.P. Trinkaus
Keyword(s):  
Cell Surface ◽  
Negative Pressure ◽  
Surface Flow ◽  
Contractile Properties ◽  
Cell Locomotion ◽  
Local Phenomenon ◽  
Constant Rate

One of the ways in which Fundulus deep cells move in vivo is by putting out long, fingerlike protrusions. This involves a change in the shape of the cell as a whole, with cytoplasmic flow, and is not just a local phenomenon. Moreover, particles on the cell surface move toward a protrusion as it is forming, suggesting surface flow. The role of surface flow is discussed both on a grown level and in respect to molecular fluidity. Long, stable protrusions can be pulled from cells by the application of negative pressure at a constant rate and these behave in a similar way to those formed during cell locomotion. Such long protrusions must be structured. The importance of contractile properties of the cytoplasm in the formation of protrusions was studied by treating cells with media that modify cellular contractility.

Regeneration and pattern formation in planarians. II. and role of cell movements in blastema formation

Development ◽  
1989 ◽  
Vol 107 (1) ◽  
pp. 69-76 ◽  
Author(s):  
E. Salo ◽  
J. Baguna
Keyword(s):  
Pattern Formation ◽  
Cell Movement ◽  
Formation Mechanisms ◽  
Blastema Formation ◽  
Chromosomal Markers ◽  
Undifferentiated Cells ◽  
Local Cell ◽  
Number Of Cells ◽  
Wound Epithelium

In planarians, blastema cells do not divide, and growth blastema is thought to result from the steady wound epithelium, of undifferentiated cells produced in the stump. However, whether these cells come only sources or whether cells placed far from the wound can participate, after long-range migrations, in the still uncertain. To study this problem, we have parameters of the process of regeneration: cell growth; number of cells produced by mitosis in the wound (postblastema); and rates of movement undifferentiated cells using grafting procedures with chromosomal markers. The results show that: (1) cells area spread (move) at higher rates than cells placed (90–140_mday-1 versus 40–50_mday-1); (2) cells than 500_m from the wound boundary are hardly 5-day-old blastemata; and (3) the number of cells within a 200–300_m postblastema area around the wound explain, provided their rates of movement are taken increasing number of blastema cells. From this, it is blastema cells in planarians originate from local mitotic activity jointly with local cell movement postblastema area around the wound match the blastema cells during regeneration. The implications for blastema growth and pattern formation mechanisms

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