scholarly journals STUDIES OF CELL DEFORMABILITY

1967 ◽  
Vol 35 (2) ◽  
pp. 347-356 ◽  
Author(s):  
Leonard Weiss
Keyword(s):  
Cell Adhesion ◽  
Calcium Ions ◽  
Alternative Hypothesis ◽  
Disodium Salt ◽  
Cell Periphery ◽  
Anionic Sites ◽  
Cell Deformability ◽  
Separation Processes ◽  
If Current

Cells grown in suspension culture were incubated with EDTA-disodium salt and shown to have more easily deformable surfaces and raised electrophoretic mobility than controls, following this treatment. The reversibility of these observations by the addition of calcium ions, and other parallel experiments, support the conclusion that, in these cells, calcium is bound to anionic sites at the cell periphery, some of which are located at the cellular electrokinetic surface. These cells should, therefore, exhibit demonstrable calcium-sensitive aggregation, if current theories on the role of calcium in the physiological situation are correct. The fact that no calcium-sensitive aggregation was observed suggests that calcium does not form "bridges" between the adjacent anionic sites on different cells, and does not act directly by its effects on the diffuse electrical double-layer in this situation. An alternative hypothesis is advanced for the role played by calcium in cell adhesion and separation processes.

scholarly journals STUDIES ON CELL DEFORMABILITY

1967 ◽  
Vol 33 (2) ◽  
pp. 341-347 ◽  
Author(s):  
Leonard Weiss
Keyword(s):  
Cell Types ◽  
Mechanical Effect ◽  
Cell Periphery ◽  
Detectable Change ◽  
Anionic Sites ◽  
Cell Deformability ◽  
Edta Treatment ◽  
Edta Solution ◽  
Hydrodynamic Slip ◽  
Sarcoma 37

The nonlethal procedure of incubation in EDTA solution makes the peripheral regions of ascites sarcoma 37 cells more easily deformable, as reflected in measurements of the decreased amount of negative pressure required to suck out standard hemispherical bulges from the cells into micropipettes. The facilitation of deformability was abolished after reincubation of cells in calcium-containing saline, and this mechanical parameter was partially restored to normal after reincubation in magnesium-containing saline; the mechanical effect of EDTA treatment is, therefore, thought to be due mainly to the removal of calcium from the cell periphery. As EDTA treatment produces no detectable change in cellular electrophoretic mobility, it is concluded that peripheral calcium must be bound to anionic sites deeper than about 10 A from the cellular hydrodynamic slip plane. The data are discussed with emphasis on the view that they should not be extrapolated freely to other cell types.

Glycoproteins and Cell Adhesion

1975 ◽  
Author(s):  
G. M. W. Cook
Keyword(s):  
Cell Adhesion ◽  
Cell Interaction ◽  
Dermal Fibroblasts ◽  
Membrane Glycoprotein ◽  
Cell Periphery ◽  
Membrane Glycoproteins ◽  
Model Compounds ◽  
Great Economy ◽  
Interaction Phenomena

Over the last decade the importance of glycoproteins at the cell surface has become increasingly evident. The role of surface heterosaccharides in cell interaction phenomena will be discussed in terms of those macromolecules providing the cell with a recognition surface; the carbohydrate groups of membrane glycoproteins may be expected to provide considerable variation in surface structure, with great economy of means, commensurate with the large number of specific interactions which take place at the cell periphery. Evidence for surface glycoproteins being involved in cell adhesion will be briefly reviewed. That adhesive specificity might be incorporated into the arrangement of sugar residues within the carbohydrate groups of surface heterosaccharides which are recognized by an appropriate glycosyltransferase on the surface of apposing cells, with the formation of mutable adhesions will be detailed by reference to recent experimental evidence, obtained with malignant rat dermal fibroblasts. In this type of work the use of exogenous glycoproteins as model compounds has proved useful, however, the need to isolate endogenous membrane glycoprotein acceptors is evident and the results of current work in this area will be described.

Mitochondrial matrix calcium ions regulate energy production in myocardium: A cytochemical study

1990 ◽  
Vol 48 (2) ◽  
pp. 166-167
Author(s):  
W.A. Jacob ◽  
R. Hertsens ◽  
A. Van Bogaert ◽  
M. De Smet
Keyword(s):  
Energy Metabolism ◽  
Calcium Ions ◽  
Energy Production ◽  
Regulation Of Respiration ◽  
Free Calcium ◽  
Mitochondrial Matrix ◽  
Cytochemical Study ◽  
Nmr Techniques

In the past most studies of the control of energy metabolism focus on the role of the phosphorylation potential ATP/ADP.Pi on the regulation of respiration. Studies using NMR techniques have demonstrated that the concentrations of these compounds for oxidation phosphorylation do not change appreciably throughout the cardiac cycle and during increases in cardiac work. Hence regulation of energy production by calcium ions, present in the mitochondrial matrix, has been the object of a number of recent studies.Three exclusively intramitochondnal dehydrogenases are key enzymes for the regulation of oxidative metabolism. They are activated by calcium ions in the low micromolar range. Since, however, earlier estimates of the intramitochondnal calcium, based on equilibrium thermodynamic considerations, were in the millimolar range, a physiological correlation was not evident. The introduction of calcium-sensitive probes fura-2 and indo-1 made monitoring of free calcium during changing energy metabolism possible. These studies were performed on isolated mitochondria and extrapolation to the in vivo situation is more or less speculative.

Platelet and Shear Rate Promote Tumor Cell Adhesion to Human Endothelial Extracellular Matrix - Absence of a Role for Platelet Cyclooxygenase

1989 ◽  
Vol 61 (03) ◽  
pp. 485-489 ◽  
Author(s):  
Eva Bastida ◽  
Lourdes Almirall ◽  
Antonio Ordinas
Keyword(s):  
Cell Adhesion ◽  
Shear Rate ◽  
Tumor Cell ◽  
Umbilical Vein ◽  
Blood Platelets ◽  
Flow Conditions ◽  
Tumor Cell Adhesion ◽  
Rate Dependent ◽  
Static Conditions

SummaryBlood platelets are thought to be involved in certain aspects of malignant dissemination. To study the role of platelets in tumor cell adherence to vascular endothelium we performed studies under static and flow conditions, measuring tumor cell adhesion in the absence or presence of platelets. We used highly metastatic human adenocarcinoma cells of the lung, cultured human umbilical vein endothelial cells (ECs) and extracellular matrices (ECM) prepared from confluent EC monolayers. Our results indicated that under static conditions platelets do not significantly increase tumor cell adhesion to either intact ECs or to exposed ECM. Conversely, the studies performed under flow conditions using the flat chamber perfusion system indicated that the presence of 2 × 105 pl/μl in the perfusate significantly increased the number of tumor cells adhered to ECM, and that this effect was shear rate dependent. The maximal values of tumor cell adhesion were obtained, in presence of platelets, at a shear rate of 1,300 sec-1. Furthermore, our results with ASA-treated platelets suggest that the role of platelets in enhancing tumor cell adhesion to ECM is independent of the activation of the platelet cyclooxygenase pathway.

Cell adhesion on chiral surface: The role of protein adsorption

2012 ◽  
Vol 90 ◽  
pp. 97-101 ◽  
Author(s):  
Feng Zhou ◽  
Lin Yuan ◽  
Dan Li ◽  
He Huang ◽  
Taolei Sun ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Protein Adsorption ◽  
Chiral Surface

scholarly journals Serine and Threonine Phosphorylation of the Paxillin LIM Domains Regulates Paxillin Focal Adhesion Localization and Cell Adhesion to Fibronectin

1998 ◽  
Vol 9 (7) ◽  
pp. 1803-1816 ◽  
Author(s):  
Michael C. Brown ◽  
Joseph A. Perrotta ◽  
Christopher E. Turner
Keyword(s):  
Cell Adhesion ◽  
Focal Adhesion ◽  
Binding Sites ◽  
Protein Localization ◽  
Model System ◽  
Lim Domain ◽  
Amino Terminal ◽  
Lim Domains ◽  
Inside Out

We have previously shown that the LIM domains of paxillin operate as the focal adhesion (FA)-targeting motif of this protein. In the current study, we have identified the capacity of paxillin LIM2 and LIM3 to serve as binding sites for, and substrates of serine/threonine kinases. The activities of the LIM2- and LIM3-associated kinases were stimulated after adhesion of CHO.K1 cells to fibronectin; consequently, a role for LIM domain phosphorylation in regulating the subcellular localization of paxillin after adhesion to fibronectin was investigated. An avian paxillin-CHO.K1 model system was used to explore the role of paxillin phosphorylation in paxillin localization to FAs. We found that mutations of paxillin that mimicked LIM domain phosphorylation accelerated fibronectin-induced localization of paxillin to focal contacts. Further, blocking phosphorylation of the LIM domains reduced cell adhesion to fibronectin, whereas constitutive LIM domain phosphorylation significantly increased the capacity of cells to adhere to fibronectin. The potentiation of FA targeting and cell adhesion to fibronectin was specific to LIM domain phosphorylation as mutation of the amino-terminal tyrosine and serine residues of paxillin that are phosphorylated in response to fibronectin adhesion had no effect on the rate of FA localization or cell adhesion. This represents the first demonstration of the regulation of protein localization through LIM domain phosphorylation and suggests a novel mechanism of regulating LIM domain function. Additionally, these results provide the first evidence that paxillin contributes to “inside-out” integrin-mediated signal transduction.

P.1.a.012 New insights from cell adhesion molecules in antidepressant action: role of ITGB3 and GAP43 genes

2014 ◽  
Vol 24 ◽  
pp. S160
Author(s):  
C. Fabbri ◽  
C. Crisafulli ◽  
D. Gurwitz ◽  
J. Stingl ◽  
R. Calati ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Adhesion Molecules ◽  
Cell Adhesion Molecules ◽  
Antidepressant Action
Sign in / Sign up

Export Citation Format

Share Document