Pemphigus an Autoimmune Disease of the Skin: Cell-Cell Separation Versus Membranal Signaling and Apoptosis in Acantholysis

1999 ◽  
pp. 197-207 ◽  
Author(s):  
Yoram Milner ◽  
Philippe Métézeau ◽  
Héléne Kiefer ◽  
Meora Finemesser ◽  
François Brégégère ◽  
...  
Keyword(s):  
Autoimmune Disease ◽  
Cell Separation ◽  
Skin Cell ◽  
Cell Cell

scholarly journals Mid2p stabilizes septin rings during cytokinesis in fission yeast

2003 ◽  
Vol 160 (7) ◽  
pp. 1083-1092 ◽  
Author(s):  
Ana Berlin ◽  
Anne Paoletti ◽  
Fred Chang
Keyword(s):  
Fission Yeast ◽  
Cell Separation ◽  
Sequence Similarity ◽  
Ring Closure ◽  
Pleckstrin Homology Domain ◽  
Wild Type ◽  
Contractile Ring ◽  
Single Ring ◽  
And Function ◽  
Cell Cell

Septins are filament-forming proteins with a conserved role in cytokinesis. In the fission yeast Schizosaccharomyces pombe, septin rings appear to be involved primarily in cell–cell separation, a late stage in cytokinesis. Here, we identified a protein Mid2p on the basis of its sequence similarity to S. pombe Mid1p, Saccharomyces cerevisiae Bud4p, and Candida albicans Int1p. Like septin mutants, mid2Δ mutants had delays in cell–cell separation. mid2Δ mutants were defective in septin organization but not contractile ring closure or septum formation. In wild-type cells, septins assembled first during mitosis in a single ring and during septation developed into double rings that did not contract. In mid2Δ cells, septins initially assembled in a single ring but during septation appeared in the cleavage furrow, forming a washer or disc structure. FRAP studies showed that septins are stable in wild-type cells but exchange 30-fold more rapidly in mid2Δ cells. Mid2p colocalized with septins and required septins for its localization. A COOH-terminal pleckstrin homology domain of Mid2p was required for its localization and function. No genetic interactions were found between mid2 and the related gene mid1. Thus, these studies identify a new factor responsible for the proper stability and function of septins during cytokinesis.

scholarly journals Extracellular domains of E-cadherin determine key mechanical phenotypes of an epithelium through cell- and non-cell-autonomous outside-in signalling

2020 ◽  
Author(s):  
D.M.K. Aladin ◽  
Y.S. Chu ◽  
R.C. Robinson ◽  
S. Dufour ◽  
V. Viasnoff ◽  
...  
Keyword(s):  
Cell Separation ◽  
Intercellular Adhesion ◽  
Type I ◽  
Cortical Tension ◽  
Extracellular Region ◽  
Epithelial Sheet ◽  
And Migration ◽  
E Cadherin ◽  
Cell Cell

Cadherins control intercellular adhesion in most metazoans. In vertebrates, intercellular adhesion differs considerably between cadherins of type-I and type-II, predominantly due to their different extracellular regions. Yet, intercellular adhesion critically depends on actomyosin contractility, in which the role of the cadherin extracellular region is unclear. Here, we dissect the roles of the Extracellular Cadherin (EC) Ig-like domains by expressing chimeric E-cadherin with E-cadherin and cadherin-7 Ig-like domains in cells naturally devoid of cadherins. Using cell-cell separation, cortical tension measurement, tissue-scale stretching and migration assays, we show that distinct EC repeats in the extracellular region of cadherins differentially modulate epithelial sheet integrity, cell-cell separation forces, and cell cortical tension through a Cdc42 pathway, which further differentially regulate epithelial tensile strength, ductility, and ultimately collective migration. Interestingly, dissipative processes rather than static adhesion energy mostly dominate cell-cell separation forces. We provide a framework for the emergence of epithelial phenotypes from cell mechanical properties dependent on EC outside-in signalling.

Modulation of scatter factor/hepatocyte growth factor activity by cell-substratum adhesion

1994 ◽  
Vol 107 (5) ◽  
pp. 1265-1275 ◽  
Author(s):  
P. Clark
Keyword(s):  
Cell Adhesion ◽  
Growth Factor ◽  
Hepatocyte Growth Factor ◽  
Cell Separation ◽  
Prolonged Exposure ◽  
Collagen Gels ◽  
Scatter Factor ◽  
Tubule Formation ◽  
Hepatocyte Growth ◽  
Cell Cell

Scatter factor/hepatocyte growth factor (SF/HGF) is a multifunctional growth and motility factor whose activities vary with cell type. Here, the composition of the substratum was found to profoundly alter the scattering activities of SF/HGF, but not its mitogenetic effects, in MDCK cells. Whereas enhancement of DNA synthesis and induction of cell flattening by SF/HGF were independent of substratum composition (i.e. occurred on both fibronectin and vitronectin surfaces), colony dispersion as a result of cell separation fails to occur or is markedly reduced on surfaces where vitronectin is the major adhesive ligand. Prolonged exposure of non-scattering cultures to SF/HGF resulted in cells at colony margins producing long protrusions, which indicate that the motility of these cells is stimulated but ‘frustrated’ by the lack of breakdown of cell-cell adhesion. Scattering therefore appears to comprise two major components: increased motility and breakdown of cell-cell adhesion. The pathway leading to the breakdown of cell-cell contacts is modulated by downstream signals from extracellular matrix receptors. When cultured on immobilised fibronectin, vitronectin or a surface containing both, colony dissociation correlates with the presence of fibronectin, suggesting that positive signals from fibronectin receptors are required for SF/HGF-induced cell separation. Comparison of the findings in this study with those of a recent report on the modulation of SF/HGF-induced tubulogenesis by ECM (Santos, O. F. P. and Nigam, S. K. (1993) Dev. Biol. 160, 293–302), where vitronectin in type-1 collagen gels alters the pattern of SF/HGF-induced MDCK tubule formation from highly branched to long and unbranched, suggests that cell motility enhancement leads to tubule formation whereas the breakdown of cell-cell adhesion is required for tubule branching.

scholarly journals Flow Cytometry Analysis of Changes in the DNA Content of the Polychlorinated Biphenyl Degrader Comamonas testosteroni TK102: Effect of Metabolites on Cell-Cell Separation

2002 ◽  
Vol 68 (10) ◽  
pp. 5104-5112 ◽  
Author(s):  
Yoshinori Hiraoka ◽  
Tohru Yamada ◽  
Keiko Tone ◽  
Yutaka Futaesaku ◽  
Kazuhide Kimbara
Keyword(s):  
Flow Cytometry ◽  
Dna Content ◽  
Cell Separation ◽  
Polychlorinated Biphenyl ◽  
Gene Replacement ◽  
Comamonas Testosteroni ◽  
Single Chromosome ◽  
Degrading Bacterium ◽  
Intermediate Metabolites ◽  
Cell Cell

ABSTRACT Flow cytometry was used to monitor changes in the DNA content of the polychlorinated biphenyl (PCB)-degrading bacterium Comamonas testosteroni TK102 during growth in the presence or absence of PCBs. In culture medium without PCBs, the majority of stationary-phase cells contained a single chromosome. In the presence of PCBs, the percentage of cells containing two chromosomes increased from 12% to approximately 50%. In contrast, addition of PCBs did not change the DNA contents of three species that are unable to degrade PCBs. In addition, highly chlorinated PCBs that are not degraded by TK102 did not result in a change in the DNA content. These results suggest that PCBs did not affect the DNA content of the cells directly; rather, the intermediate metabolites resulting from the degradation of PCBs caused the increase in DNA content. To study the effect of intermediate metabolites on the DNA content of the cells, four bph genes, bphA1, bphB, bphC, and bphD, were disrupted by gene replacement. The resulting mutant strains accumulated intermediate metabolites when they were grown in the presence of PCBs or biphenyl (BP). When the bphB gene was disrupted, the percentage of cells containing two chromosomes increased in cultures grown with PCBs or BP. When grown with BP, cultures of this mutant accumulated two intermediate metabolites, 2-hydroxybiphenyl (2-OHBP) and 3-OHBP. Addition of 2- or 3-OHBP to a wild-type TK102 and non-PCB-degrading species culture also resulted in an increase in the percentage of cells containing two chromosomes. Electron microscopy revealed that cell-cell separation was inhibited in this culture. This is the first report that hydroxy-BPs can inhibit bacterial cell separation while allowing continued DNA replication.

scholarly journals Collectively stabilizing and orienting posterior migratory forces disperses cell clusters in vivo

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
B. Lin ◽  
J. Luo ◽  
R. Lehmann
Keyword(s):  
Cell Separation ◽  
Primordial Germ Cells ◽  
Cell Clusters ◽  
Epithelial Cancers ◽  
Migration Program ◽  
Contractile Forces ◽  
G Protein Coupled ◽  
Mutant Cells ◽  
Cell Cell

Abstract Individual cells detach from cohesive ensembles during development and can inappropriately separate in disease. Although much is known about how cells separate from epithelia, it remains unclear how cells disperse from clusters lacking apical–basal polarity, a hallmark of advanced epithelial cancers. Here, using live imaging of the developmental migration program of Drosophila primordial germ cells (PGCs), we show that cluster dispersal is accomplished by stabilizing and orienting migratory forces. PGCs utilize a G protein coupled receptor (GPCR), Tre1, to guide front-back migratory polarity radially from the cluster toward the endoderm. Posteriorly positioned myosin-dependent contractile forces pull on cell–cell contacts until cells release. Tre1 mutant cells migrate randomly with transient enrichment of the force machinery but fail to separate, indicating a temporal contractile force threshold for detachment. E-cadherin is retained on the cell surface during cell separation and augmenting cell–cell adhesion does not impede detachment. Notably, coordinated migration improves cluster dispersal efficiency by stabilizing cell–cell interfaces and facilitating symmetric pulling. We demonstrate that guidance of inherent migratory forces is sufficient to disperse cell clusters under physiological settings and present a paradigm for how such events could occur across development and disease.

The kic1 kinase of schizosaccharomyces pombe is a CLK/STY orthologue that regulates cell–cell separation

2003 ◽  
Vol 283 (1) ◽  
pp. 101-115 ◽  
Author(s):  
Zhaohua Tang ◽  
Linda L Mandel ◽  
Shyue-Lee Yean ◽  
Cindy X Lin ◽  
Tina Chen ◽  
...  
Keyword(s):  
Schizosaccharomyces Pombe ◽  
Cell Separation ◽  
Cell Cell

scholarly journals Extracellular domains of E-cadherin determine key mechanical phenotypes of an epithelium through cell- and non-cell-autonomous outside-in signaling

PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0260593
Author(s):  
Darwesh Mohideen Kaderbatcha Aladin ◽  
Yeh Shiu Chu ◽  
Shuo Shen ◽  
Robert Charles Robinson ◽  
Sylvie Dufour ◽  
...  
Keyword(s):  
Cell Separation ◽  
Intercellular Adhesion ◽  
Type I ◽  
Cortical Tension ◽  
Extracellular Region ◽  
Epithelial Sheet ◽  
And Migration ◽  
E Cadherin ◽  
Cell Cell

Cadherins control intercellular adhesion in most metazoans. In vertebrates, intercellular adhesion differs considerably between cadherins of type-I and type-II, predominantly due to their different extracellular regions. Yet, intercellular adhesion critically depends on actomyosin contractility, in which the role of the cadherin extracellular region is unclear. Here, we dissect the roles of the Extracellular Cadherin (EC) Ig-like domains by expressing chimeric E-cadherin with E-cadherin and cadherin-7 Ig-like domains in cells naturally devoid of cadherins. Using cell-cell separation, cortical tension measurement, tissue stretching and migration assays, we show that distinct EC repeats in the extracellular region of cadherins differentially modulate epithelial sheet integrity, cell-cell separation forces, and cell cortical tension with the Cdc42 pathway, which further differentially regulate epithelial tensile strength, ductility, and ultimately collective migration. Interestingly, dissipative processes rather than static adhesion energy mostly dominate cell-cell separation forces. We provide a framework for the emergence of epithelial phenotypes from cell mechanical properties dependent on EC outside-in signaling.

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