scholarly journals Response of basal epithelial cell surface and Cytoskeleton to solubilized extracellular matrix molecules.

1981 ◽  
Vol 91 (1) ◽  
pp. 45-54 ◽  
Author(s):  
S P Sugrue ◽  
E D Hay
Keyword(s):  
Extracellular Matrix ◽  
Cell Surface ◽  
Basal Cell ◽  
Actin Filaments ◽  
Cell Cortex ◽  
Collagen Gels ◽  
Basal Surface ◽  
Extracellular Matrix Components ◽  
Cytoplasmic Processes

Corneal epithelium removed from underlying extracellular matrix (ECM) extends numerous cytoplasmic processes (blebs) from the formerly smooth basal surface. If blebbing epithelia are grown on collagen gels or lens capsules in vitro, the basal surface flattens and takes on the smooth contour typical of epithelium in contact with basal lamina in situ. This study examines the effect of soluble extracellular matrix components on the basal surface. Corneal epithelia from 9- to 11-d-old chick embryos were isolated with trypsin-collagenase or ethylenediamine tetraacetic acid, then placed on Millipore filters (Millipore Corp., Bedford, Mass.), and cultured at the medium-air interface. Media were prepared with no serum, with 10% of calf serum, or with serum from which plasma fibronectin was removed. Epithelia grown on filters in this medium continue to bleb for the duration of the experiments (12-14 h). If soluble collagen, laminin, or fibronectin is added to the medium, however, blebs are withdrawn and by 2-6 h the basal surface is flat. Epithelia grown on filters in the presence of albumin, IgG, or glycosaminoglycans continue to bleb. Epithelia cultured on solid substrata, such as glass, also continue to bleb if ECM is absent from the medium. The basal cell cortex in situ contains a compact cortical mat of filaments that decorate with S-1 myosin subfragments; some, if not all, of these filaments point away from the plasmalemma. The actin filaments disperse into the cytoplasmic processes during blebbing and now many appear to point toward the plasmalemma. In isolated epithelia that flatten in response to soluble collagens, laminin, and fibronectin, the actin filaments reform the basal cortical mat typical or epithelial in situ. Thus, extracellular macromolecules influence and organize not only the basal cell surface but also the actin-rich basal cell cortex of epithelial cells.

scholarly journals Lactobacillus Cell Surface Proteins Involved in Interaction with Mucus and Extracellular Matrix Components

2020 ◽  
Vol 77 (12) ◽  
pp. 3831-3841
Author(s):  
Lidia Muscariello ◽  
Barbara De Siena ◽  
Rosangela Marasco
Keyword(s):  
Extracellular Matrix ◽  
Cell Surface ◽  
Intestinal Flora ◽  
Surface Proteins ◽  
Matrix Proteins ◽  
Cell Surface Proteins ◽  
Host Interaction ◽  
Extracellular Matrix Components ◽  
Probiotic Strains ◽  
Matrix Components

AbstractThe gut microbiota is a complex microbial ecosystem where bacteria, through mutual interactions, cooperate in maintaining of wellbeing and health. Lactobacilli are among the most important constituents of human and animal intestinal microbiota and include many probiotic strains. Their presence ensures protection from invasion of pathogens, as well as stimulation of the immune system and protection of the intestinal flora, often exerted through the ability to interact with mucus and extracellular matrix components. The main factors responsible for mediating adhesion of pathogens and commensals to the gut are cell surface proteins that recognize host targets, as mucus layer and extracellular matrix proteins. In the last years, several adhesins have been reported to be involved in lactobacilli–host interaction often miming the same mechanism used by pathogens.

scholarly journals Analysis of the role of microfilaments and microtubules in acquisition of bipolarity and elongation of fibroblasts in hydrated collagen gels.

1984 ◽  
Vol 99 (2) ◽  
pp. 536-549 ◽  
Author(s):  
J J Tomasek ◽  
E D Hay
Keyword(s):  
Actin Cytoskeleton ◽  
Shape Change ◽  
Cell Cortex ◽  
Collagen Gels ◽  
Actin Cortex ◽  
Microtubule Disruption ◽  
Corneal Fibroblasts ◽  
Fourth Step ◽  
Collagenous Stroma

Fibroblasts in situ reside within a collagenous stroma and are elongate and bipolar in shape. If isolated and grown on glass, they change from elongate to flat shape, lose filopodia, and acquire ruffles. This shape change can be reversed to resemble that in situ by suspending the cells in hydrated collagen gels. In this study of embryonic avian corneal fibroblasts grown in collagen gels, we describe for the first time the steps in the acquisition of the elongate shape and analyze the effect of cytoskeleton-disrupting drugs on filopodial activity, assumption of bipolarity, and cell elongation within extracellular matrix. We have previously shown by immunofluorescence that filopodia contain actin but not myosin and are free of organelles. The cell cortex is rich in actin and the cytosol, in myosin. By using antitubulin, we show in the present study that microtubules are aligned along the long axis of the bipolar cell body. The first step in assumption of the elongate shape is extension of filopodia by the round cells suspended in collagen, and this is not significantly affected by the drugs we used: taxol to stabilize microtubules; nocodazole to disassemble microtubules; and cytochalasin D to disrupt microfilaments. The second step, movement of filopodia to opposite ends of the cell, is disrupted by cytochalasin, but not by taxol or nocodazole. The third step, extension of pseudopodia and acquisition of bipolarity similarly requires intact actin, but not microtubules. If fibroblasts are allowed to become bipolar before drug treatment, moreover, they remain so in the presence of the drugs. To complete the fourth step, extensive elongation of the cell, both intact actin and microtubules are required. Retraction of the already elongated cell occurs on microtubule disruption, but retraction requires an intact actin cytoskeleton. We suggest that the cell interacts with surrounding collagen fibrils via its actin cytoskeleton to become bipolar in shape, and that microtubules interact with the actin cortex to bring about the final elongation of the fibroblast.

Syndecan, a developmentally regulated cell surface proteoglycan that binds extracellular matrix and growth factors

1990 ◽  
Vol 327 (1239) ◽  
pp. 171-186 ◽  
Keyword(s):  
Extracellular Matrix ◽  
Growth Factor ◽  
Cell Surface ◽  
Cell Shape ◽  
Heparan Sulphate ◽  
Tissue Type ◽  
Cell Behaviour ◽  
Extracellular Matrix Components ◽  
Cellular Behaviour ◽  
Cell Surface Proteoglycan

Cellular behaviour during development is dictated, in part, by the insoluble extracellular matrix and the soluble growth factor peptides, the major molecules responsible for integrating cells into morphologically and functionally defined groups. These extracellular molecules influence cellular behaviour by binding at the cell surface to specific receptors that transduce intracellular signals in various ways not yet fully clear. Syndecan, a cell surface proteoglycan found predominantly on epithelia in mature tissues binds both extracellular matrix components (fibronectin, collagens I, III, V, and thrombospondin) and basic fibroblast growth factor (bFGF). Syndecan consists of chondroitin sulfate and heparan sulphate chains linked to a 31 kilodalton (kDa) integral membrane protein. Syndecan represents a family of integral membrane proteoglycans that differ in extracellular domains, but share cytoplasmic domains. Syndecan behaves as a matrix receptor: it binds selectively to components of the extracellular matrix, associates intracellularly with the actin cytoskeleton when cross-linked at the cell surface, its extracellular domain is shed upon cell rounding and it localizes solely to basolateral surfaces of simple epithelia. Mammary epithelial cells made syndecan-deficient become fibroblastic in morphology and cell behaviour, showing that syndecan maintains epithelial cell morphology. Syndecan changes in quantity, location and structure during development: it appears initially on four-cell embryos (prior to its known matrix ligands), becomes restricted in the pre-implementation embryo to the cells that will form the embryo proper, changes its expression due to epithelial-mesenchymal interactions (for example, induced in kidney mesenchyme by the ureteric bud), and with association of cells with extracellular matrix (for example, during B-cell differentiation), and ultimately, in mature tissues becomes restricted to epithelial tissues. The number and size of its glycosaminoglycan chains vary with changes in cell shape and organization yielding tissue type-specific polymorphic forms of syndecan. Its interactions with the major extracellular effector molecules that influence cell behaviour, its role in maintaining cell shape and its spatial and temporal changes in expression during development indicate that syndecan is involved in morphogenesis.

scholarly journals Expression of extracellular matrix components is regulated by substratum.

1990 ◽  
Vol 110 (4) ◽  
pp. 1405-1415 ◽  
Author(s):  
C H Streuli ◽  
M J Bissell
Keyword(s):  
Extracellular Matrix ◽  
Epithelial Cells ◽  
Basement Membrane ◽  
Type I Collagen ◽  
Basement Membranes ◽  
Type I ◽  
Collagen Gels ◽  
Extracellular Matrix Components ◽  
Matrix Components ◽  
Cells Cultured

Reconstituted basement membranes and extracellular matrices have been demonstrated to affect, positively and dramatically, the production of milk proteins in cultured mammary epithelial cells. Here we show that both the expression and the deposition of extracellular matrix components themselves are regulated by substratum. The steady-state levels of the laminin, type IV collagen, and fibronectin mRNAs in mammary epithelial cells cultured on plastic dishes and on type I collagen gels have been examined, as has the ability of these cells to synthesize, secrete, and deposit laminin and other, extracellular matrix proteins. We demonstrate de novo synthesis of a basement membrane by cells cultured on type I collagen gels which have been floated into the medium. Expression of the mRNA and proteins of basement membranes, however, are quite low in these cultures. In contrast, the levels of laminin, type IV collagen, and fibronectin mRNAs are highest in cells cultured on plastic surfaces, where no basement membrane is deposited. It is suggested that the interaction between epithelial cells and both basement membrane and stromally derived matrices exerts a negative influence on the expression of mRNA for extracellular matrix components. In addition, we show that the capacity for lactational differentiation correlates with conditions that favor the deposition of a continuous basement membrane, and argue that the interaction between specialized epithelial cells and stroma enables them to create their own microenvironment for accurate signal transduction and phenotypic function.

Extracellular matrix and breast cancer cells' response to trastuzumab: The role of glycosaminoglycans, heparanases, and syndecan-1.

2012 ◽  
Vol 30 (15_suppl) ◽  
pp. 10568-10568
Author(s):  
Maria Aparecida Silva Pinhal ◽  
Eloah Rabello Suarez ◽  
Helena Bonciani Nader ◽  
Auro Del Giglio
Keyword(s):  
Breast Cancer ◽  
Extracellular Matrix ◽  
Cell Surface ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Antibody Activity ◽  
Trastuzumab Resistance ◽  
Mcf7 Cells ◽  
Her2 Positive ◽  
Extracellular Matrix Components

10568 Background: Trastuzumab is an antibody anti-epidermal growth factor 2 receptor (HER2), which improves disease-free and overall survival in HER2 positive breast cancer. Nevertheless, many patients become resistant to this treatment. Heparanase (HPSE) is an enzyme that is responsible for removal of heparan sulfate (HS) chains from proteoglycans, generating free oligosaccharides that modulate many physiopathological functions, including tumor developing. We have analyzed whether some extracellular matrix components influence trastuzumab efficacy. Methods: Heparanase-1 (HPSE-1) overexpression effect was analyzed using MCF7 cells stable transfected with HPSE-1 cDNA (MCF7-HPSE-1). HPSE-1, HPSE-2, Syndecan-1 (Syn-1) and HER2 expression, HPSE-1 activity and cell viability were evaluated in different breast cancer cells treated or not with trastuzumab. The glycosaminoglycans synthesis and shedding were also evaluated. Trastuzumab and HS binding were analyzed by confocal microscopy and Fluorescence Resonance Energy Transfer (FRET). Results: MCF7 transfected with HPSE-1 cDNA becomes completely resistant to trastuzumab. HS affinity by Trastuzumab was then tested, showing that they bind in high levels and this binding is necessary to antibody activity. In MCF7 cells, trastuzumab decreases HPSE-1, HPSE-2, HER2 and Syn-1 mRNA expression, while in MCF7-HPSE-1 the antibody increases the expression of these molecules. Conclusions: Our results have demonstrated that an ideal concentration of HS in cell surface, regulated by trastuzumab, is necessary to its action, beyond HER2 high levels. High HS concentration at cell surface enhances the antibody amount disposable to interact with HER2 in cell surface, determining breast cancer cells susceptibility to trastuzumab. These new insights could be useful when devising strategies for overcoming trastuzumab resistance in HER2 positive cancers. Supported by FAPESP, CNPq, CAPES.

Ultrastructural identification of extracellular matrix and cell surface components during limb morphogenesis in man

Development ◽  
1975 ◽  
Vol 34 (1) ◽  
pp. 1-18
Author(s):  
Robert O. Kelley
Keyword(s):  
Extracellular Matrix ◽  
Cell Surface ◽  
Basal Lamina ◽  
Mesenchymal Cell ◽  
Ruthenium Red ◽  
Human Hand ◽  
Binding Characteristics ◽  
Limb Morphogenesis ◽  
Testicular Hyaluronidase

Development of the human hand plate (stages 16–17) has been analyzed with emphasis on differentiation of elements within the extracellular matrix and the composition of the mesenchymal cell surface. The epithelial—mesenchymal interface contains a basal lamina and a sublaminar matrix exhibiting: (a) collagen fibrils with characteristic 63–64 nm banding; (b) non-banded filaments, 10–15 nm in diameter; (c) ruthenium red-positive particles, 12–15 nm in diameter; and (d) attenuated threads, 3·5–5·0 nm in diameter which interconnect particles, fibrils, filaments and the basal lamina. Processes of mesenchymal cells penetrate this matrix network. In addition to staining with ruthenium red, components of basal laminae bind to ferritin-conjugated Concanavalin A, greatest binding being localized on the mesenchymal surface of the lamina. Asymmetry of binding is removed by incubation of exposed laminae with trypsin (5 µg/ml). Regional differences in these staining and binding characteristics within the subepithelial matrix have not been observed in the hand plate. However, precartilaginous extracellular zones deep within the plate are notably unstructured in comparison to the sublaminar region. Ruthenium red-positive materials at mesenchymal cell surfaces display sensitivity to testicular hyaluronidase, Pronase and trypsin but resist removal with neuraminidase and EDTA. These features of the substrate in situ may be important in the regulation of mesenchymal cell behavior during limb morphogenesis in man.

scholarly journals Stress fibers in the splenic sinus endothelium in situ: molecular structure, relationship to the extracellular matrix, and contractility.

1986 ◽  
Vol 102 (5) ◽  
pp. 1738-1747 ◽  
Author(s):  
D Drenckhahn ◽  
J Wagner
Keyword(s):  
Extracellular Matrix ◽  
Plasma Membrane ◽  
Actin Filaments ◽  
Stress Fiber ◽  
Stress Fibers ◽  
Cell Type ◽  
Isolated Cells ◽  
Human Spleen ◽  
Permeabilized Cells

In the present study, we investigated structural and functional aspects of stress fibers in a cell type in situ, i.e., the sinus endothelium of the human spleen. In this cell type, stress fibers extend underneath the basal plasma membrane and are arranged parallel to the cellular long axis. Ultrastructurally, the stress fibers were found to be composed of thin actin-like filaments (5-8 nm) and thick myosin-like filaments (10-15 nm X 300 nm). Actin filaments displayed changes in polarity (determined by S-1-myosin subfragment decoration), which may allow a sliding filament mechanism. At their plasmalemmal attachment sites, actin filaments exhibited uniform polarity with the S-1-arrowhead complexes pointing away from the plasma membrane. Fluorescence microscopy showed that the stress fibers have a high affinity for phalloidin and antibodies to actin, myosin, tropomyosin, and alpha-actinin. Vinculin was confined to the cytoplasmic aspect of the plasmalemmal termination sites of stress fibers, while laminin, fibronectin, and collagens were located at the extracellular aspect of these stress fiber-membrane associations. Western blot analysis revealed polypeptide bands that contained actin, myosin, and alpha-actinin to be major components of isolated cells. Exposure of permeabilized cells to MgATP results in prominent changes in cellular shape caused by stress fiber contraction. It is concluded that the stress fibers in situ anchored to cell-to-extracellular matrix contacts can create tension that might allow the endothelium to resist the fluid shear forces of blood flow.

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