Michelman invests in adhesion system

2019 ◽  
Vol 63 (3) ◽  
pp. 108 ◽  
Keyword(s):  
Adhesion System

Mutant cadherin affects epithelial morphogenesis and invasion, but not transformation

2001 ◽  
Vol 114 (6) ◽  
pp. 1237-1246 ◽  
Author(s):  
M.L. Troxell ◽  
D.J. Loftus ◽  
W.J. Nelson ◽  
J.A. Marrs
Keyword(s):  
Tumor Progression ◽  
Mdck Cells ◽  
Collagen Gel ◽  
Collagen Matrix ◽  
Soft Agar ◽  
Epithelial Morphogenesis ◽  
Adhesion System ◽  
Severe Impairment ◽  
Hepatocyte Growth ◽  
E Cadherin

MDCK cells were engineered to reversibly express mutant E-cadherin protein with a large extracellular deletion. Mutant cadherin overexpression reduced the expression of endogenous E- and K-cadherins in MDCK cells to negligible levels, resulting in decreased cell adhesion. Despite severe impairment of the cadherin adhesion system, cells overexpressing mutant E-cadherin formed fluid-filled cysts in collagen gel cultures and responded to hepatocyte growth factor/scatter factor (HGF/SF) that induced cellular extension formation with a frequency similar to that of control cysts. However, cells were shed from cyst walls into the lumen and into the collagen matrix prior to and during HGF/SF induced tubule extension. Despite the propensity for cell dissociation, MDCK cells lacking cadherin adhesion molecules were not capable of anchorage-independent growth in soft agar and cell proliferation rate was not affected. Thus, cadherin loss does not induce transformation, despite inducing an invasive phenotype, a later stage of tumor progression. These experiments are especially relevant to tumor progression in cells with altered E-cadherin expression, particularly tumor samples with identified E-cadherin extracellular domain genomic mutations.

Invasive behaviour of glioblastoma cell lines is associated with altered organisation of the cadherin-catenin adhesion system

2002 ◽  
Vol 115 (16) ◽  
pp. 3331-3340 ◽  
Author(s):  
Carla Perego ◽  
Cristina Vanoni ◽  
Silvia Massari ◽  
Andrea Raimondi ◽  
Sandra Pola ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Cell Lines ◽  
Protein A ◽  
Cell Types ◽  
Glioblastoma Cell ◽  
Migration Assay ◽  
Adhesion System ◽  
Pdz Protein ◽  
Glioblastoma Cell Lines ◽  
Cell Cell

As little is known about the role of cadherin-mediated cell-cell adhesion in astrocytes and its alteration in migrating and invasive glioblastomas, we investigated its molecular composition and organisation in primary cultured astrocytes and the T98G and U373MG glioblastoma cell lines. Biochemical and morphological analysis indicated that all three cell types express all of the structural components of the adhesion system, including the LIN-7 PDZ protein,a novel component involved in the organisation of the junctional domain in epithelia and neurons. However, only the astrocytes and T98G cells generated and maintained mature adhesive junctional domains to which LIN-7 was recruited. Alterations in the junctional domain of U373MG cells were associated with higher motility in a poly-L-lysine migration assay. When the T98G cells were cultured on Matrigel matrix, they acquired invasive properties but, despite unchanged cadherin adhesion system protein levels, the invasive T98G cell-cell contacts failed to accumulate LIN-7 and failed to mature. These results identify the LIN-7 PDZ protein as a marker of cell adhesion maturity and cell invasion and indicate that instability and disorganisation of cadherin-mediated junctions rather than reduced expression of cadherin-catenin system components are required to promote migration and invasiveness in glioblastoma cell lines.

Limits to optimization: fluid dynamics, adhesive strength and the evolution of shape in limpet shells

2000 ◽  
Vol 203 (17) ◽  
pp. 2603-2622 ◽  
Author(s):  
M.W. Denny
Keyword(s):  
Fluid Dynamics ◽  
Shell Height ◽  
Adhesive System ◽  
Hydrodynamic Forces ◽  
Optimal Shape ◽  
Shell Morphology ◽  
Rocky Shores ◽  
Adhesion System ◽  
Selection For ◽  
Lift And Drag

Limpets are commonly found on wave-swept rocky shores, where they may be subjected to water velocities in excess of 20 m s(−1). These extreme flows can impose large forces (lift and drag), challenging the animal's ability to adhere to the substratum. It is commonly thought that the conical shape of limpet shells has evolved in part to reduce these hydrodynamic forces while providing a large aperture for adhesion. This study documents how lift and drag actually vary with the shape of limpet-like models and uses these data to explore the potential of hydrodynamic forces to serve as a selective factor in the evolution of limpet shell morphology. At a low ratio of shell height to shell radius, lift is the dominant force, while at high ratios of height to radius drag is dominant. The risk of dislodgment is minimized when the ratio of height to radius is 1.06 and the apex is in the center of the shell. Real limpets are seldom optimally shaped, however, with a typical height-to-radius ratio of 0.68 and an apex well anterior of the shell's center. The disparity between the actual and the hydrodynamically optimal shape of shells may be due to the high tenacity of limpets' adhesive system. Most limpets adhere to the substratum so strongly that they are unlikely to be dislodged by lift or drag regardless of the shape of their shell. The evolution of a tenacious adhesion system (perhaps in response to predation) has thus preempted selection for a hydrodynamically optimal shell, allowing the shell to respond to alternative selective factors.

Catenins in Xenopus embryogenesis and their relation to the cadherin-mediated cell-cell adhesion system

Development ◽  
1993 ◽  
Vol 118 (2) ◽  
pp. 629-640 ◽  
Author(s):  
S. Schneider ◽  
K. Herrenknecht ◽  
S. Butz ◽  
R. Kemler ◽  
P. Hausen
Keyword(s):  
Cell Adhesion ◽  
Plasma Membranes ◽  
Early Embryo ◽  
Xenopus Embryo ◽  
Free Form ◽  
Beta Catenin ◽  
Metabolic Labelling ◽  
Adhesion System ◽  
E Cadherin ◽  
Cell Cell

In the course of an analysis of cell-cell adhesion in the Xenopus embryo, antibodies directed against alpha- and beta-catenin were applied to investigate their relation to the cadherins occurring early in this system. The results demonstrate that alpha- and beta-catenin are provided maternally and increase in amount throughout embryogenesis. Immunoprecipitations indicate that both of the catenins are complexed to U-cadherin in the early phase of embryogenesis and to E-cadherin, when it appears during gastrulation. An excess of alpha-catenin occurs in free form in the early embryo, whereas all of the beta-catenin seems to be complexed to cadherin. Synthesis of the two components throughout early embryogenesis and their binding to newly synthesized cadherins were demonstrated by metabolic labelling. The spatial distribution of alpha-catenin was analysed by immunohistology. During cleavage alpha-catenin is deposited evenly along the plasma membranes within the embryo, while the cell peripheries at the surface of the embryo remain devoid of alpha-catenin. At later stages, the pattern of alpha-catenin distribution becomes more complex. Quantitative differences in the intensity of staining along the plasma membranes in the different regions of the embryo can be distinguished. Particularly the appearance of E-cadherin in the gastrula ectoderm is accompanied by conspicuous depositions of alpha-catenin along the respective plasma membranes in this layer. All cells in the later embryo, apart from the neural crest cells, carry alpha-catenin on their plasma membranes indicating the universal character of cadherin-mediated cell-cell adhesion in the Xenopus embryo.

scholarly journals A Novel Approach of Promoting Adhesion of Reinforcing Cord to Elastomers by Plasma Polymerization

Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 577 ◽  
Author(s):  
Wilma Dierkes ◽  
André Louis ◽  
Jacques Noordermeer ◽  
Anke Blume
Keyword(s):  
Plasma Treatment ◽  
Polyethylene Terephthalate ◽  
Plasma Polymerization ◽  
Promising Alternative ◽  
Resorcinol Formaldehyde ◽  
Plasma Activation ◽  
Novel Approach ◽  
Adhesion System ◽  
Adhesion Level ◽  
Sulfur Containing

Adhesion of cords to elastomers is crucial for many elastomeric products, such as tires and V-belts. The best adhesion system so far is based on a combination of resorcinol, formaldehyde, and a latex (RFL). However, this cord treatment has serious disadvantages in terms of processing and toxicity. A promising alternative is a plasma treatment of the cords prior to be embedded in the elastomer. For rayon cords, a plasma polymerization of sulfur-containing precursors results in adhesion levels close to RFL treatment. However, for polyethylene terephthalate (PET) cords, this treatment is not satisfactory. For this type of cords, a water-plasma activation followed by a silane dip is more promising, as 72% of the adhesion level of RFL treatment could be achieved. For rayon, an even higher adhesion level was realized.

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