Metavinculin modulates force transduction in cell adhesion sites

AbstractVinculin is a ubiquitously expressed protein, crucial for the regulation of force transduction in cells. Muscle cells express a vinculin splice-isoform called metavinculin, which has been associated with cardiomyopathies. However, the molecular function of metavinculin has remained unclear and its role for heart muscle disorders undefined. Here, we have employed a set of piconewton-sensitive tension sensors to probe metavinculin mechanics in cells. Our experiments reveal that metavinculin bears higher molecular forces but is less frequently engaged as compared to vinculin, leading to altered force propagation in cell adhesions. In addition, we have generated knockout mice to investigate the consequences of metavinculin loss in vivo. Unexpectedly, these animals display an unaltered tissue response in a cardiac hypertrophy model. Together, the data reveal that the transduction of cell adhesion forces is modulated by expression of metavinculin, yet its role for heart muscle function seems more subtle than previously thought.

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Single-Cell Probe Force Studies to Identify Sox2 Overexpression-Promoted Cell Adhesion in MCF7 Breast Cancer Cells

Cells ◽

10.3390/cells9040935 ◽

2020 ◽

Vol 9 (4) ◽

pp. 935

Author(s):

Jagoba Iturri ◽

Andreas Weber ◽

María d.M. Vivanco ◽

José L. Toca-Herrera

Keyword(s):

Breast Cancer ◽

Cell Adhesion ◽

Single Cell ◽

Cancer Cells ◽

Breast Cancer Cells ◽

Force Measurement ◽

Adhesion Forces ◽

Adhesion Properties ◽

Area Of Interest

The replacement of the cantilever tip by a living cell in Atomic Force Microscopy (AFM) experiments permits the direct quantification of cell–substrate and cell–cell adhesion forces. This single-cell probe force measurement technique, when complemented by microscopy, allows controlled manipulation of the cell with defined location at the area of interest. In this work, a setup based on two glass half-slides, a non-fouling one with bacterial S-layer protein SbpA from L. sphaericus CMM 2177 and the second with a fibronectin layer, has been employed to measure the adhesion of MCF7 breast cancer cells to fibronectin films (using SbpA as control) and to other cells (symmetric vs. asymmetric systems). The measurements aimed to characterize and compare the adhesion capacities of parental cells and cells overexpressing the embryonic transcription factor Sox2, which have a higher capacity for invasion and are more resistant to endocrine therapy in vivo. Together with the use of fluorescence techniques (epifluorescence, Total Internal Fluorescence Microscopy (TIRF)), the visualization of vinculin and actin distribution in cells in contact with fibronectin surfaces is enabled, facilitating the monitoring and quantification of the formation of adhesion complexes. These findings demonstrate the strength of this combined approach to assess and compare the adhesion properties of cell lines and to illustrate the heterogeneity of adhesive strength found in breast cancer cells.

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Epithelial Cell Adhesion Molecule (Ep-CAM) Modulates Cell–Cell Interactions Mediated by Classic Cadherins

The Journal of Cell Biology ◽

10.1083/jcb.139.5.1337 ◽

1997 ◽

Vol 139 (5) ◽

pp. 1337-1348 ◽

Cited By ~ 187

Author(s):

Sergey V. Litvinov ◽

Maarten Balzar ◽

Manon J. Winter ◽

Hellen A.M. Bakker ◽

Inge H. Briaire-de Bruijn ◽

...

Keyword(s):

Cell Adhesion ◽

Epithelial Cells ◽

Adhesion Molecule ◽

Insoluble Fraction ◽

Parental Cell ◽

Cell Interactions ◽

Cell Adhesions ◽

In Cells ◽

Cell Cell

The contribution of noncadherin-type, Ca2+-independent cell–cell adhesion molecules to the organization of epithelial tissues is, as yet, unclear. A homophilic, epithelial Ca2+-independent adhesion molecule (Ep-CAM) is expressed in most epithelia, benign or malignant proliferative lesions, or during embryogenesis. Here we demonstrate that ectopic Ep-CAM, when expressed in cells interconnected by classic cadherins (E- or N-cadherin), induces segregation of the transfectants from the parental cell type in coaggregation assays and in cultured mixed aggregates, respectively. In the latter assay, Ep-CAM–positive transfectants behave like cells with a decreased strength of cell–cell adhesion as compared to the parental cells. Using transfectants with an inducible Ep-CAM–cDNA construct, we demonstrate that increasing expression of Ep-CAM in cadherin-positive cells leads to the gradual abrogation of adherens junctions. Overexpression of Ep-CAM has no influence on the total amount of cellular cadherin, but affects the interaction of cadherins with the cytoskeleton since a substantial decrease in the detergent-insoluble fraction of cadherin molecules was observed. Similarly, the detergent-insoluble fractions of α- and β-catenins decreased in cells overexpressing Ep-CAM. While the total β-catenin content remains unchanged, a reduction in total cellular α-catenin is observed as Ep-CAM expression increases. As the cadherin-mediated cell–cell adhesions diminish, Ep-CAM–mediated intercellular connections become predominant. An adhesion-defective mutant of Ep-CAM lacking the cytoplasmic domain has no effect on the cadherin-mediated cell–cell adhesions. The ability of Ep-CAM to modulate the cadherin-mediated cell–cell interactions, as demonstrated in the present study, suggests a role for this molecule in development of the proliferative, and probably malignant, phenotype of epithelial cells, since an increase of Ep-CAM expression was observed in vivo in association with hyperplastic and malignant proliferation of epithelial cells.

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Effect of Some Metabolic Inhibitors on Vinblastine-Induced Ribosomal-Granular Material Complexes

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100066796 ◽

1971 ◽

Vol 29 ◽

pp. 548-549

Author(s):

Awtar Krishan ◽

Dora Hsu

Keyword(s):

Granular Material ◽

Rna Synthesis ◽

Culture Medium ◽

Actinomycin D ◽

Metabolic Inhibitors ◽

Protein And Rna Synthesis ◽

Apparent Reduction ◽

Plant Alkaloids ◽

In Cells

Cells exposed to antitumor plant alkaloids, vinblastine and vincristine sulfate have large proteinacious crystals and complexes of ribosomes, helical polyribosomes and electron-dense granular material (ribosomal complexes) in their cytoplasm, Binding of H3-colchicine by the in vivo crystals shows that they contain microtubular proteins. Association of ribosomal complexes with the crystals suggests that these structures may be interrelated.In the present study cultured human leukemic lymphoblasts (CCRF-CEM), were incubated with protein and RNA-synthesis inhibitors, p. fluorophenylalanine, puromycin, cycloheximide or actinomycin-D before the addition of crystal-inducing doses of vinblastine to the culture medium. None of these compounds could completely prevent the formation of the ribosomal complexes or the crystals. However, in cells pre-incubated with puromycin, cycloheximide, or actinomycin-D, a reduction in the number and size of the ribosomal complexes was seen. Large helical polyribosomes were absent in the ribosomal complexes of cells treated with puromycin, while in cells exposed to cycloheximide, there was an apparent reduction in the number of ribosomes associated with the ribosomal complexes (Fig. 2).

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Faculty Opinions recommendation of cis-Dimer formation of E-cadherin is independent of cell-cell adhesion assembly in vivo.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1018391.209464 ◽

2004 ◽

Author(s):

Deborah Leckband

Keyword(s):

Cell Adhesion ◽

Dimer Formation ◽

E Cadherin ◽

Cell Cell

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Faculty Opinions recommendation of Mechanisms and Functions of Vinculin Interactions with Phospholipids at Cell Adhesion Sites.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.726056069.793512997 ◽

2016 ◽

Author(s):

Norma Allewell

Keyword(s):

Cell Adhesion ◽

Adhesion Sites

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(Preprint)

10.2196/preprints.12282 ◽

2018 ◽

Author(s):

Dr Malathi Dayalan ◽

Dr Sudeshna Sharma ◽

Dr Shweta Poovani ◽

Dr Saher Altaf

Keyword(s):

Myofascial Pain ◽

Mouth Opening ◽

Masticatory Muscles ◽

Matched Pair ◽

Masticatory Muscle ◽

Muscle Disorders ◽

Occlusal Contact ◽

Group I ◽

Group Ii

BACKGROUND Masticatory system is a complex functional unit, primarily engaged in chewing, swallowing and breathing functions, and some parts are involved in taste recognition and determination of food consistency. Sophisticated functional performances of speech and emotional expressions are specifically human qualities. Irregularities in occlusion appears to be the precipitating factor in the pathogenesis of myofascial pain dysfunction syndrome. Tek- Scan III records the bite length, number, distribution, timing, duration and the relative force of each tooth contact. It also records the sequence of occlusal contacts in terms of time and the associated force with each occlusal contact. The aim of this study was to treat masticatory muscle disorders with occlusal equilibration, and compare the efficacy of treatment outcomes between selective grinding and stabilization splints using Tek-Scan III. OBJECTIVE Objective of this study was to compare the efficacy of occlusal equilibration achieved through selective griding and stabilization splints using Tek-Scan III. METHODS In this in vivo study, 40 patients with masticatory muscle disorders were selected based on the inclusion and exclusion criteria. The occlusal discrepancies were analyzed using Tek-Scan III. The selected 40 subjects were then randomly divided into 2 groups based on the treatment they recieved; Group I – Selective grinding group (20) and Group II – Stabilization splint group (20). Comparison of pre-treatment and post treatment results were evaluated in terms of pain, mouth opening, left and right side force percentage as recorded through Tek-Scan III and reduction of disclusion time. Statistical analysis was carried out with Kolmogorov Smirnov test, Wilcoxon matched pair test and Mann-Whitney U test. RESULTS Wilcoxon matched pairs test demonstrated that there was statistically significant results ( p = 0.0007) in both the groups for reduction of disclusion time, elimination of pain and improved mouth opening. Patients in Group I showed better results as compared to Group II in terms of disclusion time, pain and mouth opening. CONCLUSIONS Occlusal equilibration brought about by reducing the disclusion time using the Tek- Scan III reduced the symptoms of pain in masticatory muscles. Patients in group I (Selective grinding) however showed better results when compared to patients in group II (Stabilization splints).

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Biologic Aspects of Expression of Stably Integrated Transgenes in Cells of the Skin In Vitro and In Vivo

Proceedings of the Association of American Physicians ◽

10.1046/j.1525-1381.1999.99225.x ◽

1999 ◽

Vol 111 (3) ◽

pp. 198-205 ◽

Cited By ~ 14

Author(s):

Gerald G. Krueger ◽

Jeffery R. Morgan ◽

Marta J. Petersen

Keyword(s):

In Cells

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1592U89, a novel carbocyclic nucleoside analog with potent, selective anti-human immunodeficiency virus activity.

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.41.5.1082 ◽

1997 ◽

Vol 41 (5) ◽

pp. 1082-1093 ◽

Cited By ~ 276

Author(s):

S M Daluge ◽

S S Good ◽

M B Faletto ◽

W H Miller ◽

M H St Clair ◽

...

Keyword(s):

Human Immunodeficiency Virus ◽

Oral Bioavailability ◽

Human Peripheral Blood ◽

Cross Resistance ◽

Immunodeficiency Virus ◽

Carbocyclic Nucleoside ◽

Hiv 1 ◽

In Cells

1592U89, (-)-(1S,4R)-4-[2-amino-6-(cyclopropylamino)-9H-purin-9-yl]-2-cyclo pentene-1-methanol, is a carbocyclic nucleoside with a unique biological profile giving potent, selective anti-human immunodeficiency virus (HIV) activity. 1592U89 was selected after evaluation of a wide variety of analogs containing a cyclopentene substitution for the 2'-deoxyriboside of natural deoxynucleosides, optimizing in vitro anti-HIV potency, oral bioavailability, and central nervous system (CNS) penetration. 1592U89 was equivalent in potency to 3'-azido-3'-deoxythymidine (AZT) in human peripheral blood lymphocyte (PBL) cultures against clinical isolates of HIV type 1 (HIV-1) from antiretroviral drug-naive patients (average 50% inhibitory concentration [IC50], 0.26 microM for 1592U89 and 0.23 microM for AZT). 1592U89 showed minimal cross-resistance (approximately twofold) with AZT and other approved HIV reverse transcriptase (RT) inhibitors. 1592U89 was synergistic in combination with AZT, the nonnucleoside RT inhibitor nevirapine, and the protease inhibitor 141W94 in MT4 cells against HIV-1 (IIIB). 1592U89 was anabolized intracellularly to its 5'-monophosphate in CD4+ CEM cells and in PBLs, but the di- and triphosphates of 1592U89 were not detected. The only triphosphate found in cells incubated with 1592U89 was that of the guanine analog (-)-carbovir (CBV). However, the in vivo pharmacokinetic, distribution, and toxicological profiles of 1592U89 were distinct from and improved over those of CBV, probably because CBV itself was not appreciably formed from 1592U89 in cells or animals (<2%). The 5'-triphosphate of CBV was a potent, selective inhibitor of HIV-1 RT, with Ki values for DNA polymerases (alpha, beta, gamma, and epsilon which were 90-, 2,900-, 1,200-, and 1,900-fold greater, respectively, than for RT (Ki, 21 nM). 1592U89 was relatively nontoxic to human bone marrow progenitors erythroid burst-forming unit and granulocyte-macrophage CFU (IC50s, 110 microM) and human leukemic and liver tumor cell lines. 1592U89 had excellent oral bioavailability (105% in the rat) and penetrated the CNS (rat brain and monkey cerebrospinal fluid) as well as AZT. Having demonstrated an excellent preclinical profile, 1592U89 has progressed to clinical evaluation in HIV-infected patients.

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