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Sample records for cadherin-mediated cell adhesion

  1. A genome-wide screen identifies conserved protein hubs required for cadherin-mediated cell–cell adhesion

    Science.gov (United States)

    Toret, Christopher P.; D’Ambrosio, Michael V.; Vale, Ronald D.; Simon, Michael A.

    2014-01-01

    Cadherins and associated catenins provide an important structural interface between neighboring cells, the actin cytoskeleton, and intracellular signaling pathways in a variety of cell types throughout the Metazoa. However, the full inventory of the proteins and pathways required for cadherin-mediated adhesion has not been established. To this end, we completed a genome-wide (∼14,000 genes) ribonucleic acid interference (RNAi) screen that targeted Ca2+-dependent adhesion in DE-cadherin–expressing Drosophila melanogaster S2 cells in suspension culture. This novel screen eliminated Ca2+-independent cell–cell adhesion, integrin-based adhesion, cell spreading, and cell migration. We identified 17 interconnected regulatory hubs, based on protein functions and protein–protein interactions that regulate the levels of the core cadherin–catenin complex and coordinate cadherin-mediated cell–cell adhesion. Representative proteins from these hubs were analyzed further in Drosophila oogenesis, using targeted germline RNAi, and adhesion was analyzed in Madin–Darby canine kidney mammalian epithelial cell–cell adhesion. These experiments reveal roles for a diversity of cellular pathways that are required for cadherin function in Metazoa, including cytoskeleton organization, cell–substrate interactions, and nuclear and cytoplasmic signaling. PMID:24446484

  2. New insights into the molecular mechanism of E-cadherin-mediated cell adhesion by free energy calculations

    DEFF Research Database (Denmark)

    Doro, Fabio; Saladino, Giorgio; Belvisi, Laura

    2015-01-01

    Three-dimensional domain swapping is an important mode of protein association leading to the formation of stable dimers. Monomers associating via this mechanism mutually exchange a domain to form a homodimer. Classical cadherins, an increasingly important target for anticancer therapy, use domain...... swapping to mediate cell adhesion. However, despite its importance, the molecular mechanism of domain swapping is still debated. Here, we study the conformational changes that lead to activation and dimerization via domain swapping of E-cadherin. Using state-of-the-art enhanced sampling atomistic......" mechanism in which monomers in an active conformational state bind to form a homodimer, analogous to the conformational selection mechanism often observed in ligand-target binding. Moreover, we find that the open state population is increased in the presence of calcium ions at the extracellular boundary...

  3. Rac1 activation inhibits E-cadherin-mediated adherens junctions via binding to IQGAP1 in pancreatic carcinoma cells

    Directory of Open Access Journals (Sweden)

    Giehl Klaudia

    2009-09-01

    Full Text Available Abstract Background Monomeric GTPases of the Rho family control a variety of cellular functions including actin cytoskeleton organisation, cell migration and cell adhesion. Defects in these regulatory processes are involved in tumour progression and metastasis. The development of metastatic carcinoma is accompanied by deregulation of adherens junctions, which are composed of E-cadherin/β- and α-catenin complexes. Results Here, we show that the activity of the monomeric GTPase Rac1 contributes to inhibition of E-cadherin-mediated cell-cell adhesion in pancreatic carcinoma cells. Stable expression of constitutively active Rac1(V12 reduced the amount of E-cadherin on protein level in PANC-1 pancreatic carcinoma cells, whereas expression of dominant negative Rac1(N17 resulted in an increased amount of E-cadherin. Extraction of proteins associated with the actin cytoskeleton as well as coimmunoprecipitation analyses demonstrated markedly decreased amounts of E-cadherin/catenin complexes in Rac1(V12-expressing cells, but increased amounts of functional E-cadherin/catenin complexes in cells expressing Rac1(N17. Cell aggregation and migration assays revealed, that cells containing less E-cadherin due to expression of Rac1(V12, exhibited reduced cell-cell adhesion and increased cell motility. The Rac/Cdc42 effector protein IQGAP1 has been implicated in regulating cell-cell adhesion. Coimmunoprecipitation studies showed a decrease in the association between IQGAP1 and β-catenin in Rac1(V12-expressing PANC-1 cells and an association of IQGAP1 with Rac1(V12. Elevated association of IQGAP1 with the E-cadherin adhesion complex via β-catenin correlated with increased intercellular adhesion of PANC-1 cells. Conclusion These results indicate that active Rac1 destabilises E-cadherin-mediated cell-cell adhesion in pancreatic carcinoma cells by interacting with IQGAP1 which is associated with a disassembly of E-cadherin-mediated adherens junctions. Inhibition

  4. The minimal essential unit for cadherin-mediated intercellular adhesion comprises extracellular domains 1 and 2

    DEFF Research Database (Denmark)

    Shan, Weisong; Yagita, Yoshiki; Wang, Zhaohui

    2004-01-01

    of the extracellular domains of N-cadherin and produced various cell lines to examine adhesion properties. We show that the first domain of N-cadherin alone on the cell surface fails to generate adhesive activity and that the first two domains of N-cadherin form the "minimal essential unit" to mediate cell adhesion...... domains of N-cadherin have distinct roles in cell adhesion, i.e. the first two domains are responsible for homophilic adhesion activity, and the other domains promote adhesion efficiency most likely by positioning essential domains relatively far out from the cell surface....

  5. Regulated binding of PTP1B-like phosphatase to N-cadherin: control of cadherin-mediated adhesion by dephosphorylation of beta-catenin

    Science.gov (United States)

    1996-01-01

    Cadherins are a family of cell-cell adhesion molecules which play a central role in controlling morphogenetic movements during development. Cadherin function is regulated by its association with the actin containing cytoskeleton, an association mediated by a complex of cytoplasmic proteins, the catenins: alpha, beta, and gamma. Phosphorylated tyrosine residues on beta-catenin are correlated with loss of cadherin function. Consistent with this, we find that only nontyrosine phosphorylated beta-catenin is associated with N-cadherin in E10 chick retina tissue. Moreover, we demonstrate that a PTP1B-like tyrosine phosphatase associates with N-cadherin and may function as a regulatory switch controlling cadherin function by dephosphorylating beta-catenin, thereby maintaining cells in an adhesion-competent state. The PTP1B-like phosphatase is itself tyrosine phosphorylated. Moreover, both direct binding experiments performed with phosphorylated and dephosphorylated molecules, and treatment of cells with tyrosine kinase inhibitors indicate that the interaction of the PTP1B-like phosphatase with N-cadherin depends on its tyrosine phosphorylation. Concomitant with the tyrosine kinase inhibitor-induced loss of the PTP1B-like phosphatase from its association with N-cadherin, phosphorylated tyrosine residues are retained on beta-catenin, the association of N- cadherin with the actin containing cytoskeleton is lost and N-cadherin- mediated cell adhesion is prevented. Tyrosine phosphatase inhibitors also result in the accumulation of phosphorylated tyrosine residues on beta-catenin, loss of the association of N-cadherin with the actin- containing cytoskeleton, and prevent N-cadherin mediated adhesion, presumably by directly blocking the function of the PTP1B-like phosphatase. We previously showed that the binding of two ligands to the cell surface N-acetylgalactosaminylphosphotransferase (GalNAcPTase), the monoclonal antibody 1B11 and a proteoglycan with a 250-kD core protein

  6. N-cadherin-mediated interaction with multiple myeloma cells inhibits osteoblast differentiation

    NARCIS (Netherlands)

    Groen, Richard W. J.; de Rooij, Martin F. M.; Kocemba, Kinga A.; Reijmers, Rogier M.; de Haan-Kramer, Anneke; Overdijk, Marije B.; Aalders, Linda; Rozemuller, Henk; Martens, Anton C. M.; Bergsagel, P. Leif; Kersten, Marie José; Pals, Steven T.; Spaargaren, Marcel

    2011-01-01

    Multiple myeloma is a hematologic malignancy characterized by a clonal expansion of malignant plasma cells in the bone marrow, which is accompanied by the development of osteolytic lesions and/or diffuse osteopenia. The intricate bi-directional interaction with the bone marrow microenvironment plays

  7. N-cadherin-mediated interaction with multiple myeloma cells inhibits osteoblast differentiation

    NARCIS (Netherlands)

    Groen, R.W.J.; de Rooij, M.F.M.; Kocemba, K.A.; Reijmers, R.M.; de Haan-Kramer, A.; Overdijk, M.B.; Aalders, L.; Rozemuller, H.; Martens, A.C.M.; Bergsagel, P.L.; Kersten, M.J.; Pals, S.T.; Spaargaren, M.

    2011-01-01

    Background Multiple myeloma is a hematologic malignancy characterized by a clonal expansion of malignant plasma cells in the bone marrow, which is accompanied by the development of osteolytic lesions and/or diffuse osteopenia. The intricate bi-directional interaction with the bone marrow

  8. Nanoscale E-Cadherin ligand patterns show threshold size for cellular adhesion and adherence junction formation

    DEFF Research Database (Denmark)

    Kristensen, Stine H; Pedersen, Gitte Albinus; Nejsum, Lene Niemann

    2012-01-01

    The role of ligand spatial distribution on the formation of cadherin mediated cell-cell contacts is studied utilizing nanopatterns of E-cadherin ligands. Protein patches ranging in size from 100 nm to 800 nm prepared by colloidal lithography critically influence adhesion, spreading and formation ...

  9. Synaptic Cell Adhesion

    OpenAIRE

    Missler, Markus; Südhof, Thomas C.; Biederer, Thomas

    2012-01-01

    Chemical synapses are asymmetric intercellular junctions that mediate synaptic transmission. Synaptic junctions are organized by trans-synaptic cell adhesion molecules bridging the synaptic cleft. Synaptic cell adhesion molecules not only connect pre- and postsynaptic compartments, but also mediate trans-synaptic recognition and signaling processes that are essential for the establishment, specification, and plasticity of synapses. A growing number of synaptic cell adhesion molecules that inc...

  10. A protocadherin-cadherin-FLRT3 complex controls cell adhesion and morphogenesis.

    Directory of Open Access Journals (Sweden)

    Xuejun Chen

    2009-12-01

    Full Text Available Paraxial protocadherin (PAPC and fibronectin leucine-rich domain transmembrane protein-3 (FLRT3 are induced by TGFbeta signaling in Xenopus embryos and both regulate morphogenesis by inhibiting C-cadherin mediated cell adhesion.We have investigated the functional and physical relationships between PAPC, FLRT3, and C-cadherin. Although neither PAPC nor FLRT3 are required for each other to regulate C-cadherin adhesion, they do interact functionally and physically, and they form a complex with cadherins. By itself PAPC reduces cell adhesion physiologically to induce cell sorting, while FLRT3 disrupts adhesion excessively to cause cell dissociation. However, when expressed together PAPC limits the cell dissociating and tissue disrupting activity of FLRT3 to make it effective in physiological cell sorting. PAPC counteracts FLRT3 function by inhibiting the recruitment of the GTPase RND1 to the FLRT3 cytoplasmic domain.PAPC and FLRT3 form a functional complex with cadherins and PAPC functions as a molecular "governor" to maintain FLRT3 activity at the optimal level for physiological regulation of C-cadherin adhesion, cell sorting, and morphogenesis.

  11. Cell surface clustering of Cadherin adhesion complex induced by antibody coated beads

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Cadherin receptors mediate cell-cell adhesion, signal transduction and assembly of cytoskeletons. How a single transmembrane molecule Cadherin can be involved in multiple functions through modulating its binding activities with many membrane adhesion molecules and cytoskeletal components is an unanswered question which can be elucidated by clues from bead experiments. Human lung cells expressing N-Cadherin were examined. After co-incubation with anti-N-Cadherin monoclonal antibody coated beads, cell surface clustering of N-Cadherin was induced. Immunofluorescent detection demonstrated that in addition to Cadherin, β-Catenin, α-Catenin, α-Actinin and Actin fluorescence also aggregated respectively at the membrane site of bead attachment. Myosin heavy chain (MHC), another major component of Actin cytoskeleton, did not aggregate at the membrane site of bead attachment. Adhesion unrelated protein Con A and polylysine conjugated beads did not induce the clustering of adhesion molecules. It is indicated that the Cadherin/Catenins/α-Actinin/Actin complex is formed at Cadherin mediated cell adherens junction; occupancy and cell surface clustering of Cadherin is crucial for the formation of Cadherin adhesion protein complexes.

  12. Syndecans and cell adhesion

    DEFF Research Database (Denmark)

    Couchman, J R; Chen, L; Woods, A

    2001-01-01

    Now that transmembrane signaling through primary cell-matrix receptors, integrins, is being elucidated, attention is turning to how integrin-ligand interactions can be modulated. Syndecans are transmembrane proteoglycans implicated as coreceptors in a variety of physiological processes, including...... cell adhesion, migration, response to growth factors, development, and tumorigenesis. This review will describe this family of proteoglycans in terms of their structures and functions and their signaling in conjunction with integrins, and indicate areas for future research....

  13. The neural cell adhesion molecule

    DEFF Research Database (Denmark)

    Berezin, V; Bock, E; Poulsen, F M

    2000-01-01

    During the past year, the understanding of the structure and function of neural cell adhesion has advanced considerably. The three-dimensional structures of several of the individual modules of the neural cell adhesion molecule (NCAM) have been determined, as well as the structure of the complex...... between two identical fragments of the NCAM. Also during the past year, a link between homophilic cell adhesion and several signal transduction pathways has been proposed, connecting the event of cell surface adhesion to cellular responses such as neurite outgrowth. Finally, the stimulation of neurite...

  14. Syndecan proteoglycans and cell adhesion

    DEFF Research Database (Denmark)

    Woods, A; Oh, E S; Couchman, J R

    1998-01-01

    It is now becoming clear that a family of transmembrane proteoglycans, the syndecans, have important roles in cell adhesion. They participate through binding of matrix ligand to their glycosaminoglycan chains, clustering, and the induction of signaling cascades to modify the internal microfilament...... organization. Syndecans can modulate the type of adhesive responses induced by other matrix ligand-receptor interactions, such as those involving the integrins, and so contribute to the control of cell morphology, adhesion and migration....

  15. Syndecans, signaling, and cell adhesion

    DEFF Research Database (Denmark)

    Couchman, J R; Woods, A

    1996-01-01

    structures within the heparan sulfate chains, leaving the roles of chondroitin sulfate chains and extracellular portion of the core proteins to be elucidated. Evidence that syndecans are a class of receptor involved in cell adhesion is mounting, and their small cytoplasmic domains may link...... transmembrane signaling from matrix to cytoskeleton, as proposed for other classes of adhesion receptors....

  16. VE-Cadherin-Mediated Epigenetic Regulation of Endothelial Gene Expression.

    Science.gov (United States)

    Morini, Marco F; Giampietro, Costanza; Corada, Monica; Pisati, Federica; Lavarone, Elisa; Cunha, Sara I; Conze, Lei L; O'Reilly, Nicola; Joshi, Dhira; Kjaer, Svend; George, Roger; Nye, Emma; Ma, Anqi; Jin, Jian; Mitter, Richard; Lupia, Michela; Cavallaro, Ugo; Pasini, Diego; Calado, Dinis P; Dejana, Elisabetta; Taddei, Andrea

    2018-01-19

    The mechanistic foundation of vascular maturation is still largely unknown. Several human pathologies are characterized by deregulated angiogenesis and unstable blood vessels. Solid tumors, for instance, get their nourishment from newly formed structurally abnormal vessels which present wide and irregular interendothelial junctions. Expression and clustering of the main endothelial-specific adherens junction protein, VEC (vascular endothelial cadherin), upregulate genes with key roles in endothelial differentiation and stability. We aim at understanding the molecular mechanisms through which VEC triggers the expression of a set of genes involved in endothelial differentiation and vascular stabilization. We compared a VEC-null cell line with the same line reconstituted with VEC wild-type cDNA. VEC expression and clustering upregulated endothelial-specific genes with key roles in vascular stabilization including claudin-5 , vascular endothelial-protein tyrosine phosphatase ( VE-PTP ), and von Willebrand factor ( vWf ). Mechanistically, VEC exerts this effect by inhibiting polycomb protein activity on the specific gene promoters. This is achieved by preventing nuclear translocation of FoxO1 (Forkhead box protein O1) and β-catenin, which contribute to PRC2 (polycomb repressive complex-2) binding to promoter regions of claudin-5 , VE-PTP , and vWf . VEC/β-catenin complex also sequesters a core subunit of PRC2 (Ezh2 [enhancer of zeste homolog 2]) at the cell membrane, preventing its nuclear translocation. Inhibition of Ezh2/VEC association increases Ezh2 recruitment to claudin-5 , VE-PTP , and vWf promoters, causing gene downregulation. RNA sequencing comparison of VEC-null and VEC-positive cells suggested a more general role of VEC in activating endothelial genes and triggering a vascular stability-related gene expression program. In pathological angiogenesis of human ovarian carcinomas, reduced VEC expression paralleled decreased levels of claudin-5 and VE-PTP. These

  17. Focal adhesions and cell-matrix interactions

    DEFF Research Database (Denmark)

    Woods, A; Couchman, J R

    1988-01-01

    Focal adhesions are areas of cell surfaces where specializations of cytoskeletal, membrane and extracellular components combine to produce stable cell-matrix interactions. The morphology of these adhesions and the components identified in them are discussed together with possible mechanisms...

  18. Detachment of Chain-Forming Neuroblasts by Fyn-Mediated Control of cell-cell Adhesion in the Postnatal Brain.

    Science.gov (United States)

    Fujikake, Kazuma; Sawada, Masato; Hikita, Takao; Seto, Yayoi; Kaneko, Naoko; Herranz-Pérez, Vicente; Dohi, Natsuki; Homma, Natsumi; Osaga, Satoshi; Yanagawa, Yuchio; Akaike, Toshihiro; García-Verdugo, Jose Manuel; Hattori, Mitsuharu; Sobue, Kazuya; Sawamoto, Kazunobu

    2018-05-09

    In the rodent olfactory system, neuroblasts produced in the ventricular-subventricular zone of the postnatal brain migrate tangentially in chain-like cell aggregates toward the olfactory bulb (OB) through the rostral migratory stream (RMS). After reaching the OB, the chains are dissociated and the neuroblasts migrate individually and radially toward their final destination. The cellular and molecular mechanisms controlling cell-cell adhesion during this detachment remain unclear. Here we report that Fyn, a nonreceptor tyrosine kinase, regulates the detachment of neuroblasts from chains in the male and female mouse OB. By performing chemical screening and in vivo loss-of-function and gain-of-function experiments, we found that Fyn promotes somal disengagement from the chains and is involved in neuronal migration from the RMS into the granule cell layer of the OB. Fyn knockdown or Dab1 (disabled-1) deficiency caused p120-catenin to accumulate and adherens junction-like structures to be sustained at the contact sites between neuroblasts. Moreover, a Fyn and N-cadherin double-knockdown experiment indicated that Fyn regulates the N-cadherin-mediated cell adhesion between neuroblasts. These results suggest that the Fyn-mediated control of cell-cell adhesion is critical for the detachment of chain-forming neuroblasts in the postnatal OB. SIGNIFICANCE STATEMENT In the postnatal brain, newly born neurons (neuroblasts) migrate in chain-like cell aggregates toward their destination, where they are dissociated into individual cells and mature. The cellular and molecular mechanisms controlling the detachment of neuroblasts from chains are not understood. Here we show that Fyn, a nonreceptor tyrosine kinase, promotes the somal detachment of neuroblasts from chains, and that this regulation is critical for the efficient migration of neuroblasts to their destination. We further show that Fyn and Dab1 (disabled-1) decrease the cell-cell adhesion between chain-forming neuroblasts

  19. Syndecans: synergistic activators of cell adhesion

    DEFF Research Database (Denmark)

    Woods, A; Couchman, J R

    1998-01-01

    Cell-surface proteoglycans participate in cell adhesion, growth-factor signalling, lipase activity and anticoagulation. Until recently, only the roles of the glycosaminoglycan chains were investigated. Now, with molecular characterization of several core proteins, the roles of each individual...... molecules modulating integrin-based adhesion....

  20. Cadherins mediate sequential roles through a hierarchy of mechanisms in the developing mammillary body

    Directory of Open Access Journals (Sweden)

    Nora eSzabo

    2015-03-01

    Full Text Available Expression of intricate combinations of cadherins (a family of adhesive membrane proteins is common in the developing central nervous system. On this basis, a combinatorial cadherin code has long been proposed to underlie neuronal sorting and to be ultimately responsible for the layers, columns and nuclei of the brain. However, experimental proof of this particular function of cadherins has proven difficult to obtain and the question is still not clear. Alternatively, non-specific, non-combinatorial, purely quantitative adhesive differentials have been proposed to explain neuronal sorting in the brain. Do cadherin combinations underlie brain cytoarchitecture? We approached this question using as model a well-defined forebrain nucleus, the mammillary body (MBO, which shows strong, homogeneous expression of one single cadherin (Cdh11 and patterned, combinatorial expression of Cdh6, -8 and -10.We found that, besides the known combinatorial Cdh pattern, MBO cells are organized into a second, non-overlapping pattern grouping neurons with the same date of neurogenesis. Abolition of Cdh11 expression in the entire MBO during development disrupted the combination-based as well as the birthdate-based sorting. In utero RNAi experiments knocking down Cdh11 in MBO-fated migrating neurons at one specific age showed that Cdh11 expression is required for chronological entrance in the MBO.Our results suggest that neuronal sorting in the developing MBO is caused by adhesion-based, non-combinatorial mechanisms that keep neurons sorted according to birthdate information (possibly matching them to target neurons chronologically sorted in the same manner. Non-specific adhesion mechanisms would also prevent cadherin combinations from altering the birthdate-based sorting. Cadherin combinations would presumably act later to support specific synaptogenesis through specific axonal fasciculation and final target recognition.

  1. Differential expression of cell adhesion genes

    DEFF Research Database (Denmark)

    Stein, Wilfred D; Litman, Thomas; Fojo, Tito

    2005-01-01

    that compare cells grown in suspension to similar cells grown attached to one another as aggregates have suggested that it is adhesion to the extracellular matrix of the basal membrane that confers resistance to apoptosis and, hence, resistance to cytotoxins. The genes whose expression correlates with poor...... in cell adhesion and the cytoskeleton. If the proteins involved in tethering cells to the extracellular matrix are important in conferring drug resistance, it may be possible to improve chemotherapy by designing drugs that target these proteins....

  2. Heterocellular cadherin connections: coordinating adhesive cues in homeostasis and cancer [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Silvia Fontenete

    2017-06-01

    Full Text Available This short insight covers some of the recent topics relevant to the field of cadherin–catenin adhesion in mediating connections between different cell types, so-called heterotypic or heterocellular connections, in both homeostasis and cancer. These scientific discoveries are increasing our understanding of how multiple cells residing in complex tissues can be instructed by cadherin adhesion receptors to regulate tissue architecture and function and how these cadherin-mediated heterocellular connections spur tumor growth and the acquisition of malignant characteristics in tumor cells. Overall, the findings that have emerged over the past few years are elucidating the complexity of the functional roles of the cadherin–catenin complexes. Future exciting research lies ahead in order to understand the physical basis of these heterotypic interactions and their influence on the behavior of heterogeneous cellular populations as well as their roles in mediating phenotypic and genetic changes as cells evolve through complex environments during morphogenesis and cancer.

  3. Structural basis of cell-cell adhesion by NCAM

    DEFF Research Database (Denmark)

    Kasper, C; Rasmussen, H; Kastrup, Jette Sandholm Jensen

    2000-01-01

    The neural cell adhesion molecule NCAM, a member of the immunoglobulin superfamily, mediates cell-cell recognition and adhesion via a homophilic interaction. NCAM plays a key role during development and regeneration of the nervous system and is involved in synaptic plasticity associated with memory...

  4. Endothelial cell adhesion to ion implanted polymers

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Y; Kusakabe, M [SONY Corp., Tokyo (Japan); Lee, J S; Kaibara, M; Iwaki, M; Sasabe, H [RIKEN (Inst. of Physical and Chemical Research), Saitama (Japan)

    1992-03-01

    The biocompatibility of ion implanted polymers has been studied by means of adhesion measurements of bovine aorta endothelial cells in vitro. The specimens used were polystyrene (PS) and segmented polyurethane (SPU). Na{sup +}, N{sub 2}{sup +}, O{sub 2}{sup +} and Kr{sup +} ion implantations were performed at an energy of 150 keV with fluences ranging from 1x10{sup 15} to 3x10{sup 17} ions/cm{sup 2} at room temperature. The chemical and physical structures of ion-implanted polymers have been investigated in order to analyze their tissue compatibility such as improvement of endothelial cell adhesion. The ion implanted SPU have been found to exhibit remarkably higher adhesion and spreading of endothelial cells than unimplanted specimens. By contrast, ion implanted PS demonstrated a little improvement of adhesion of cells in this assay. Results of FT-IR-ATR showed that ion implantation broke the original chemical bond to form new radicals such as OH, ....C=O, SiH and condensed rings. The results of Raman spectroscopy showed that ion implantation always produced a peak near 1500 cm{sup -1}, which indicated that these ion implanted PS and SPU had the same carbon structure. This structure is considered to bring the dramatic increase in the extent of cell adhesion and spreading to these ion implanted PS and SPU. (orig.).

  5. Cell adhesion during bullet motion in capillaries.

    Science.gov (United States)

    Takeishi, Naoki; Imai, Yohsuke; Ishida, Shunichi; Omori, Toshihiro; Kamm, Roger D; Ishikawa, Takuji

    2016-08-01

    A numerical analysis is presented of cell adhesion in capillaries whose diameter is comparable to or smaller than that of the cell. In contrast to a large number of previous efforts on leukocyte and tumor cell rolling, much is still unknown about cell motion in capillaries. The solid and fluid mechanics of a cell in flow was coupled with a slip bond model of ligand-receptor interactions. When the size of a capillary was reduced, the cell always transitioned to "bullet-like" motion, with a consequent decrease in the velocity of the cell. A state diagram was obtained for various values of capillary diameter and receptor density. We found that bullet motion enables firm adhesion of a cell to the capillary wall even for a weak ligand-receptor binding. We also quantified effects of various parameters, including the dissociation rate constant, the spring constant, and the reactive compliance on the characteristics of cell motion. Our results suggest that even under the interaction between P-selectin glycoprotein ligand-1 (PSGL-1) and P-selectin, which is mainly responsible for leukocyte rolling, a cell is able to show firm adhesion in a small capillary. These findings may help in understanding such phenomena as leukocyte plugging and cancer metastasis. Copyright © 2016 the American Physiological Society.

  6. Collective cell streams in epithelial monolayers depend on cell adhesion

    International Nuclear Information System (INIS)

    Czirók, András; Varga, Katalin; Méhes, Előd; Szabó, András

    2013-01-01

    We report spontaneously emerging, randomly oriented, collective streaming behavior within a monolayer culture of a human keratinocyte cell line, and explore the effect of modulating cell adhesions by perturbing the function of calcium-dependent cell adhesion molecules. We demonstrate that decreasing cell adhesion induces narrower and more anisotropic cell streams, reminiscent of decreasing the Taylor scale of turbulent liquids. To explain our empirical findings, we propose a cell-based model that represents the dual nature of cell–cell adhesions. Spring-like connections provide mechanical stability, while a cellular Potts model formalism represents surface-tension driven attachment. By changing the relevance and persistence of mechanical links between cells, we are able to explain the experimentally observed changes in emergent flow patterns. (paper)

  7. Film adhesion in amorphous silicon solar cells

    Indian Academy of Sciences (India)

    TECS

    Film adhesion in amorphous silicon solar cells. A R M YUSOFF*, M N SYAHRUL and K HENKEL. Malaysia Energy Centre, 8th Floor, North Wing, Sapura @ Mines, 7, Jalan Tasik, The Mines Resort City,. 43300 Seri Kembangan, Selangor Darul Ehsan. MS received 11 April 2007. Abstract. A major issue encountered ...

  8. Cell adhesion on nanotextured slippery superhydrophobic substrates.

    Science.gov (United States)

    Di Mundo, Rosa; Nardulli, Marina; Milella, Antonella; Favia, Pietro; d'Agostino, Riccardo; Gristina, Roberto

    2011-04-19

    In this work, the response of Saos2 cells to polymeric surfaces with different roughness/density of nanometric dots produced by a tailored plasma-etching process has been studied. Topographical features have been evaluated by atomic force microscopy, while wetting behavior, in terms of water-surface adhesion energy, has been evaluated by measurements of drop sliding angle. Saos2 cytocompatibility has been investigated by scanning electron microscopy, fluorescent microscopy, and optical microscopy. The similarity in outer chemical composition has allowed isolation of the impact of the topographical features on cellular behavior. The results indicate that Saos2 cells respond differently to surfaces with different nanoscale topographical features, clearly showing a certain inhibition in cell adhesion when the nanoscale is particularly small. This effect appears to be attenuated in surfaces with relatively bigger nanofeatures, though these express a more pronounced slippery/dry wetting character. © 2011 American Chemical Society

  9. Cell adhesion pattern created by OSTE polymers.

    Science.gov (United States)

    Liu, Wenjia; Li, Yiyang; Ding, Xianting

    2017-04-24

    Engineering surfaces with functional polymers is a crucial issue in the field of micro/nanofabrication and cell-material interface studies. For many applications of surface patterning, it does not need cells to attach on the whole surface. Herein, we introduce a novel polymer fabrication protocol of off-stoichiometry thiol-ene (OSTE) polymers to create heterogeneity on the surface by utilizing 3D printing and soft-lithography. By choosing two OSTE polymers with different functional groups, we create a pattern where only parts of the surface can facilitate cell adhesion. We also study the hydrophilic property of OSTE polymers by mixing poly(ethylene glycol) (PEG) directly with pre-polymers and plasma treatments afterwards. Moreover, we investigate the effect of functional groups' excess ratio and hydrophilic property on the cell adhesion ability of OSTE polymers. The results show that the cell adhesion ability of OSTE materials can be tuned within a wide range by the coupling effect of functional groups' excess ratio and hydrophilic property. Meanwhile, by mixing PEG with pre-polymers and undergoing oxygen plasma treatment afterward can significantly improve the hydrophilic property of OSTE polymers.

  10. Optical biosensors for cell adhesion.

    Science.gov (United States)

    Ramsden, Jeremy J; Horvath, Robert

    2009-01-01

    Planar optical waveguides offer an ideal substratum for cells on which to reside. The materials from which the waveguides are made--high refractive index transparent dielectrics--correspond to the coatings of medical implants (e.g., the oxides of niobium, tantalum, and titanium) or the high molecular weight polymers used for culture flasks (e.g., polystyrene). The waveguides can furthermore be modified both chemically and morphologically while retaining their full capability for generating an evanescent optical field that has its greatest strength at the interface between the solid substratum and the liquid phase with which it is invariably in contact (i.e., the culture medium bathing the cells), decaying exponentially perpendicular to the interface at a rate controllable by varying the material parameters of the waveguide. Analysis of the perturbation of the evanescent field by the presence of living cells within it enables their size, number density, shape, refractive index (linked to their constitution) and so forth to be determined, the number of parameters depending on the number of waveguide lightmodes analyzed. No labeling of any kind is necessary, and convenient measurement setups are fully compatible with maintaining the cells in their usual environment. If the temporal evolution of the perturbation is analyzed, even more information can be obtained, such as the amount of material (microexudate) secreted by the cell while residing on the surface. Separation of parallel effects simultaneously contributing to the perturbation of the evanescent field can be accomplished by analysis of coupling peak shape when a grating coupler is used to measure the propagation constants of the waveguide lightmodes.

  11. Vaginal epithelial cells regulate membrane adhesiveness to co-ordinate bacterial adhesion.

    Science.gov (United States)

    Younes, Jessica A; Klappe, Karin; Kok, Jan Willem; Busscher, Henk J; Reid, Gregor; van der Mei, Henny C

    2016-04-01

    Vaginal epithelium is colonized by different bacterial strains and species. The bacterial composition of vaginal biofilms controls the balance between health and disease. Little is known about the relative contribution of the epithelial and bacterial cell surfaces to bacterial adhesion and whether and how adhesion is regulated over cell membrane regions. Here, we show that bacterial adhesion forces with cell membrane regions not located above the nucleus are stronger than with regions above the nucleus both for vaginal pathogens and different commensal and probiotic lactobacillus strains involved in health. Importantly, adhesion force ratios over membrane regions away from and above the nucleus coincided with the ratios between numbers of adhering bacteria over both regions. Bacterial adhesion forces were dramatically decreased by depleting the epithelial cell membrane of cholesterol or sub-membrane cortical actin. Thus, epithelial cells can regulate membrane regions to which bacterial adhesion is discouraged, possibly to protect the nucleus. © 2015 John Wiley & Sons Ltd.

  12. Characterizing phenolformaldehyde adhesive cure chemistry within the wood cell wall

    Science.gov (United States)

    Daniel J. Yelle; John Ralph

    2016-01-01

    Adhesive bonding of wood using phenol-formaldehyde remains the industrial standard in wood product bond durability. Not only does this adhesive infiltrate the cell wall, it also is believed to form primary bonds with wood cell wall polymers, particularly guaiacyl lignin. However, the mechanism by which phenol-formaldehyde adhesive intergrally interacts and bonds to...

  13. Cell surface N-glycans influence the level of functional E-cadherin at the cell–cell border

    Directory of Open Access Journals (Sweden)

    M. Kristen Hall

    2014-01-01

    Full Text Available E-cadherin is crucial for adhesion of cells to each other and thereby development and maintenance of tissue. While it is has been established that N-glycans inside the cell impact the level of E-cadherin at the cell surface of epithelial-derived cells, it is unclear whether N-glycans outside the cell control the clustering of E-cadherin at the cell–cell border. Here, we demonstrate reduction of N-glycans at the cell surface weakened the recruitment and retention of E-cadherin at the cell–cell border, and consequently reduced the strength of cell–cell interactions. We conclude that N-glycans at the cell surface are tightly linked to the placement of E-cadherin at the cell–cell border and thereby control E-cadherin mediated cell–cell adhesion.

  14. Focal adhesion kinase maintains, but not increases the adhesion of dental pulp cells.

    Science.gov (United States)

    Qian, Yuyan; Shao, Meiying; Zou, Wenlin; Wang, Linyan; Cheng, Ran; Hu, Tao

    2017-04-01

    Focal adhesion kinase (FAK) functions as a key enzyme in the integrin-mediated adhesion-signalling pathway. Here, we aimed to investigate the effects of FAK on adhesion of human dental pulp (HDP) cells. We transfected lentiviral vectors to silence or overexpress FAK in HDP cells ex vivo. Early cell adhesion, cell survival and focal contacts (FCs)-related proteins (FAK and paxillin) were examined. By using immunofluorescence, the formation of FCs and cytoskeleton was detected, respectively. We found that both adhesion and survival of HDP cells were suppressed by FAK inhibition. However, FAK overexpression slightly inhibited cell adhesion and exhibited no change in cell survival compared with the control. A thick rim of cytoskeleton accumulated and smaller dot-shaped FCs appeared in FAK knockdown cells. Phosphorylation of paxillin (p-paxillin) was inhibited in FAK knockdown cells, verifying that the adhesion was inhibited. Less cytoskeleton and elongated FCs were observed in FAK-overexpressed cells. However, p-paxillin had no significant difference compared with the control. In conclusion, the data suggest that FAK maintains cell adhesion, survival and cytoskeleton formation, but excessive FAK has no positive effects on these aspects.

  15. Amperometric Adhesion Signals of Liposomes, Cells and Droplets

    OpenAIRE

    Ivošević DeNardis, N.; Žutić, V.; Svetličić, V.; Frkanec, R.

    2009-01-01

    Individual soft microparticles (liposomes, living cells and organic droplets) in aqueous media are characterized by their adhesion signals using amperometry at the dropping mercury electrode. We confirmed that the general mechanism established for adhesion of hydrocarbon droplets and cells is valid as well for liposome adhesion within a wide range of surface charge densities. Incidents and shape of adhesion signals in liposome suspensions reflect liposome polydispersity, surface charge den...

  16. Probing bacterial adhesion at the single-cell level

    DEFF Research Database (Denmark)

    Zeng, Guanghong; Müller, Torsten; Meyer, Rikke Louise

    be considered. We have developed a simple and versatile method to make single-cell bacterial probes for measuring single cell adhesion by force spectroscopy using atomic force microscopy (AFM). A single-cell probe was readily made by picking up a bacterial cell from a glass surface by approaching a tipless AFM...... cantilever coated with the commercial cell adhesive CellTakTM. We applied the method to study adhesion of living cells to abiotic surfaces at the single-cell level. Immobilisation of single bacterial cells to the cantilever was stable for several hours, and viability was confirmed by Live/Dead staining...... on the adhesion force, we explored the bond formation and adhesive strength of four different bacterial strains towards three abiotic substrates with variable hydrophobicity and surface roughness. The adhesion force and final rupture length were dependent on bacterial strains, surfaces properties, and time...

  17. Cell Adhesion on Surface-Functionalized Magnesium.

    Science.gov (United States)

    Wagener, Victoria; Schilling, Achim; Mainka, Astrid; Hennig, Diana; Gerum, Richard; Kelch, Marie-Luise; Keim, Simon; Fabry, Ben; Virtanen, Sannakaisa

    2016-05-18

    The biocompatibility of commercially pure magnesium-based (cp Mg) biodegradable implants is compromised of strong hydrogen evolution and surface alkalization due to high initial corrosion rates of cp Mg in the physiological environment. To mitigate this problem, the addition of corrosion-retarding alloying elements or coating of implant surfaces has been suggested. In the following work, we explored the effect of organic coatings on long-term cell growth. cp Mg was coated with aminopropyltriehtoxysilane + vitamin C (AV), carbonyldiimidazole (CDI), or stearic acid (SA). All three coatings have been previously suggested to reduce initial corrosion and to enhance protein adsorption and hence cell adhesion on magnesium surfaces. Endothelial cells (DH1+/+) and osteosarcoma cells (MG63) were cultured on coated samples for up to 20 days. To quantify Mg corrosion, electrochemical impedance spectroscopy (EIS) was measured after 1, 3, and 5 days of cell culture. We also investigated the speed of initial cell spreading after seeding using fluorescently labeled fibroblasts (NIH/3T3). Hydrogen evolution after contact with cell culture medium was markedly decreased on AV- and SA-coated Mg compared to uncoated Mg. These coatings also showed improved cell adhesion and spreading after 24 h of culture comparable to tissue-treated plastic surfaces. On AV-coated cp Mg, a confluent layer of endothelial cells formed after 5 days and remained intact for up to 20 days. Together, these data demonstrate that surface coating with AV is a viable strategy for improving long-term biocompatibility of cp Mg-based implants. EIS measurements confirmed that the presence of a confluent cell layer increased the corrosion resistance.

  18. The role of adhesion energy in controlling cell?cell contacts

    OpenAIRE

    Ma?tre, Jean-L?on; Heisenberg, Carl-Philipp

    2011-01-01

    Recent advances in microscopy techniques and biophysical measurements have provided novel insight into the molecular, cellular and biophysical basis of cell adhesion. However, comparably little is known about a core element of cell?cell adhesion?the energy of adhesion at the cell?cell contact. In this review, we discuss approaches to understand the nature and regulation of adhesion energy, and propose strategies to determine adhesion energy between cells in vitro and in vivo.

  19. Tuning cell adhesion by direct nanostructuring silicon into cell repulsive/adhesive patterns

    International Nuclear Information System (INIS)

    Premnath, Priyatha; Tavangar, Amirhossein; Tan, Bo; Venkatakrishnan, Krishnan

    2015-01-01

    Developing platforms that allow tuning cell functionality through incorporating physical, chemical, or mechanical cues onto the material surfaces is one of the key challenges in research in the field of biomaterials. In this respect, various approaches have been proposed and numerous structures have been developed on a variety of materials. Most of these approaches, however, demand a multistep process or post-chemical treatment. Therefore, a simple approach would be desirable to develop bio-functionalized platforms for effectively modulating cell adhesion and consequently programming cell functionality without requiring any chemical or biological surface treatment. This study introduces a versatile yet simple laser approach to structure silicon (Si) chips into cytophobic/cytophilic patterns in order to modulate cell adhesion and proliferation. These patterns are fabricated on platforms through direct laser processing of Si substrates, which renders a desired computer-generated configuration into patterns. We investigate the morphology, chemistry, and wettability of the platform surfaces. Subsequently, we study the functionality of the fabricated platforms on modulating cervical cancer cells (HeLa) behaviour. The results from in vitro studies suggest that the nanostructures efficiently repel HeLa cells and drive them to migrate onto untreated sites. The study of the morphology of the cells reveals that cells evade the cytophobic area by bending and changing direction. Additionally, cell patterning, cell directionality, cell channelling, and cell trapping are achieved by developing different platforms with specific patterns. The flexibility and controllability of this approach to effectively structure Si substrates to cell-repulsive and cell-adhesive patterns offer perceptible outlook for developing bio-functionalized platforms for a variety of biomedical devices. Moreover, this approach could pave the way for developing anti-cancer platforms that selectively repel

  20. Tuning cell adhesion by direct nanostructuring silicon into cell repulsive/adhesive patterns

    Energy Technology Data Exchange (ETDEWEB)

    Premnath, Priyatha, E-mail: priyatha.premnath@ryerson.ca [Micro/Nanofabrication Laboratory, Department of Mechanical and Industrial Engineering, Ryerson University, 350 Victoria Street, Toronto, ON, Canada M5B 2K3 (Canada); Tavangar, Amirhossein, E-mail: atavanga@ryerson.ca [Micro/Nanofabrication Laboratory, Department of Mechanical and Industrial Engineering, Ryerson University, 350 Victoria Street, Toronto, ON, Canada M5B 2K3 (Canada); Tan, Bo, E-mail: tanbo@ryerson.ca [Nanocharacterization Laboratory, Department of Aerospace Engineering, Ryerson University, 350 Victoria Street, Toronto, ON, Canada M5B 2K3 (Canada); Venkatakrishnan, Krishnan, E-mail: venkat@ryerson.ca [Micro/Nanofabrication Laboratory, Department of Mechanical and Industrial Engineering, Ryerson University, 350 Victoria Street, Toronto, ON, Canada M5B 2K3 (Canada)

    2015-09-10

    Developing platforms that allow tuning cell functionality through incorporating physical, chemical, or mechanical cues onto the material surfaces is one of the key challenges in research in the field of biomaterials. In this respect, various approaches have been proposed and numerous structures have been developed on a variety of materials. Most of these approaches, however, demand a multistep process or post-chemical treatment. Therefore, a simple approach would be desirable to develop bio-functionalized platforms for effectively modulating cell adhesion and consequently programming cell functionality without requiring any chemical or biological surface treatment. This study introduces a versatile yet simple laser approach to structure silicon (Si) chips into cytophobic/cytophilic patterns in order to modulate cell adhesion and proliferation. These patterns are fabricated on platforms through direct laser processing of Si substrates, which renders a desired computer-generated configuration into patterns. We investigate the morphology, chemistry, and wettability of the platform surfaces. Subsequently, we study the functionality of the fabricated platforms on modulating cervical cancer cells (HeLa) behaviour. The results from in vitro studies suggest that the nanostructures efficiently repel HeLa cells and drive them to migrate onto untreated sites. The study of the morphology of the cells reveals that cells evade the cytophobic area by bending and changing direction. Additionally, cell patterning, cell directionality, cell channelling, and cell trapping are achieved by developing different platforms with specific patterns. The flexibility and controllability of this approach to effectively structure Si substrates to cell-repulsive and cell-adhesive patterns offer perceptible outlook for developing bio-functionalized platforms for a variety of biomedical devices. Moreover, this approach could pave the way for developing anti-cancer platforms that selectively repel

  1. Cell-Cell Adhesion and Breast Cancer.

    Science.gov (United States)

    1998-01-01

    Lodish, H., Baltimore, D., Berk, A., Zipurski, S. L, Matsudaira, P., and J. Darnell. (1995). Molecular Cell Biology. Scientific American Books , New...Bruhn, L., Wedlich, D., Grosschedl, R., and Birchmeier, W. (1996) Nature 382, 638-642 6. Molenaar , M., van de Wetering, M., Oosterwegel, M., Peterson

  2. Cell Adhesions: Actin-Based Modules that Mediate Cell-Extracellular Matrix and Cell-Cell Interactions

    Science.gov (United States)

    Bachir, Alexia; Horwitz, Alan Rick; Nelson, W. James; Bianchini, Julie M.

    2018-01-01

    Cell adhesions link cells to the extracellular matrix (ECM) and to each other, and depend on interactions with the actin cytoskeleton. Both cell-ECM and cell-cell adhesion sites contain discrete, yet overlapping functional modules. These modules establish physical association with the actin cytoskeleton, locally modulate actin organization and dynamics, and trigger intracellular signaling pathways. Interplay between these modules generates distinct actin architectures that underlie different stages, types, and functions of cell-ECM and cell-cell adhesions. Actomyosin contractility is required to generate mature, stable adhesions, as well as sense and translate the mechanical properties of the cellular environment to changes in cell organization and behavior. In this chapter we discuss the organization and function of different adhesion modules and how they interact with the actin cytoskeleton. We highlight the molecular mechanisms of mechanotransduction in adhesions, and how adhesion molecules mediate crosstalk between cell-ECM and cell-cell adhesion sites. PMID:28679638

  3. Cleavage and Cell Adhesion Properties of Human Epithelial Cell Adhesion Molecule (HEPCAM)*

    Science.gov (United States)

    Tsaktanis, Thanos; Kremling, Heidi; Pavšič, Miha; von Stackelberg, Ricarda; Mack, Brigitte; Fukumori, Akio; Steiner, Harald; Vielmuth, Franziska; Spindler, Volker; Huang, Zhe; Jakubowski, Jasmine; Stoecklein, Nikolas H.; Luxenburger, Elke; Lauber, Kirsten; Lenarčič, Brigita; Gires, Olivier

    2015-01-01

    Human epithelial cell adhesion molecule (HEPCAM) is a tumor-associated antigen frequently expressed in carcinomas, which promotes proliferation after regulated intramembrane proteolysis. Here, we describe extracellular shedding of HEPCAM at two α-sites through a disintegrin and metalloprotease (ADAM) and at one β-site through BACE1. Transmembrane cleavage by γ-secretase occurs at three γ-sites to generate extracellular Aβ-like fragments and at two ϵ-sites to release human EPCAM intracellular domain HEPICD, which is efficiently degraded by the proteasome. Mapping of cleavage sites onto three-dimensional structures of HEPEX cis-dimer predicted conditional availability of α- and β-sites. Endocytosis of HEPCAM warrants acidification in cytoplasmic vesicles to dissociate protein cis-dimers required for cleavage by BACE1 at low pH values. Intramembrane cleavage sites are accessible and not part of the structurally important transmembrane helix dimer crossing region. Surprisingly, neither chemical inhibition of cleavage nor cellular knock-out of HEPCAM using CRISPR-Cas9 technology impacted the adhesion of carcinoma cell lines. Hence, a direct function of HEPCAM as an adhesion molecule in carcinoma cells is not supported and appears to be questionable. PMID:26292218

  4. Cell Adhesion to Plasma-Coated PVC

    Directory of Open Access Journals (Sweden)

    Elidiane C. Rangel

    2014-01-01

    Full Text Available To produce environments suitable for cell culture, thin polymer films were deposited onto commercial PVC plates from radiofrequency acetylene-argon plasmas. The proportion of argon in the plasmas, PAr, was varied from 5.3 to 65.8%. The adhesion and growth of Vero cells on the coated surfaces were examined for different incubation times. Cytotoxicity tests were performed using spectroscopic methods. Carbon, O, and N were detected in all the samples using XPS. Roughness remained almost unchanged in the samples prepared with 5.3 and 28.9% but tended to increase for the films deposited with PAr between 28.9 and 55.3%. Surface free energy increased with increasing PAr, except for the sample prepared at 28.9% of Ar, which presented the least reactive surface. Cells proliferated on all the samples, including the bare PVC. Independently of the deposition condition there was no evidence of cytotoxicity, indicating the viability of such coatings for designing biocompatible devices.

  5. E-cadherin Mediates the Preventive Effect of Vitamin D3 in Colitis-associated Carcinogenesis.

    Science.gov (United States)

    Xin, Yu; He, Longmei; Luan, Zijian; Lv, Hong; Yang, Hong; Zhou, Ying; Zhao, Xinhua; Zhou, Weixun; Yu, Songlin; Tan, Bei; Wang, Hongying; Qian, Jiaming

    2017-09-01

    Vitamin D3 is beneficial in ameliorating or preventing inflammation and carcinogenesis. Here, we evaluated if vitamin D3 has a preventive effect on colitis-associated carcinogenesis. Administration of azoxymethane (AOM), followed with dextran sulfate sodium (DSS), was used to simulate colitis-associated colon cancer in mice. The supplement of vitamin D3 at different dosages (15, 30, 60 IU·g·w), started before AOM or immediately after DSS treatment (post 60), was sustained to the end of the experiment. Dietary vitamin D3 significantly reduced the number of tumors and tumor burden in a dose-dependent manner. Of note, vitamin D3 in high doses showed significant preventive effects on carcinogenesis regardless of administration before or after AOM-DSS treatment. Cell proliferation decreased in vitamin D3 groups compared with the control group after inhibition of expression of β-catenin and its downstream target gene cyclin D1 in the colon. In vitro, vitamin D3 reduced the transcriptional activity and nuclear level of β-catenin, and it also increased E-cadherin expression and its binding affinity for β-catenin. Moreover, repression of E-cadherin was rescued by supplemental vitamin D3 in mouse colons. Taken together, our results indicate that vitamin D3 effectively suppressed colonic carcinogenesis in the AOM-DSS mouse model. Our findings further suggest that upregulation of E-cadherin contributes to the preventive effect of vitamin D3 on β-catenin activity.

  6. Interstitial cell migration: integrin-dependent and alternative adhesion mechanisms.

    NARCIS (Netherlands)

    Schmidt, S.; Friedl, P.H.A.

    2010-01-01

    Adhesion and migration are integrated cell functions that build, maintain and remodel the multicellular organism. In migrating cells, integrins are the main transmembrane receptors that provide dynamic interactions between extracellular ligands and actin cytoskeleton and signalling machineries. In

  7. The cancer cell adhesion resistome: mechanisms, targeting and translational approaches.

    Science.gov (United States)

    Dickreuter, Ellen; Cordes, Nils

    2017-06-27

    Cell adhesion-mediated resistance limits the success of cancer therapies and is a great obstacle to overcome in the clinic. Since the 1990s, where it became clear that adhesion of tumor cells to the extracellular matrix is an important mediator of therapy resistance, a lot of work has been conducted to understand the fundamental underlying mechanisms and two paradigms were deduced: cell adhesion-mediated radioresistance (CAM-RR) and cell adhesion-mediated drug resistance (CAM-DR). Preclinical work has evidently demonstrated that targeting of integrins, adapter proteins and associated kinases comprising the cell adhesion resistome is a promising strategy to sensitize cancer cells to both radiotherapy and chemotherapy. Moreover, the cell adhesion resistome fundamentally contributes to adaptation mechanisms induced by radiochemotherapy as well as molecular drugs to secure a balanced homeostasis of cancer cells for survival and growth. Intriguingly, this phenomenon provides a basis for synthetic lethal targeted therapies simultaneously administered to standard radiochemotherapy. In this review, we summarize current knowledge about the cell adhesion resistome and highlight targeting strategies to override CAM-RR and CAM-DR.

  8. Single cell adhesion assay using computer controlled micropipette.

    Directory of Open Access Journals (Sweden)

    Rita Salánki

    Full Text Available Cell adhesion is a fundamental phenomenon vital for all multicellular organisms. Recognition of and adhesion to specific macromolecules is a crucial task of leukocytes to initiate the immune response. To gain statistically reliable information of cell adhesion, large numbers of cells should be measured. However, direct measurement of the adhesion force of single cells is still challenging and today's techniques typically have an extremely low throughput (5-10 cells per day. Here, we introduce a computer controlled micropipette mounted onto a normal inverted microscope for probing single cell interactions with specific macromolecules. We calculated the estimated hydrodynamic lifting force acting on target cells by the numerical simulation of the flow at the micropipette tip. The adhesion force of surface attached cells could be accurately probed by repeating the pick-up process with increasing vacuum applied in the pipette positioned above the cell under investigation. Using the introduced methodology hundreds of cells adhered to specific macromolecules were measured one by one in a relatively short period of time (∼30 min. We blocked nonspecific cell adhesion by the protein non-adhesive PLL-g-PEG polymer. We found that human primary monocytes are less adherent to fibrinogen than their in vitro differentiated descendants: macrophages and dendritic cells, the latter producing the highest average adhesion force. Validation of the here introduced method was achieved by the hydrostatic step-pressure micropipette manipulation technique. Additionally the result was reinforced in standard microfluidic shear stress channels. Nevertheless, automated micropipette gave higher sensitivity and less side-effect than the shear stress channel. Using our technique, the probed single cells can be easily picked up and further investigated by other techniques; a definite advantage of the computer controlled micropipette. Our experiments revealed the existence of a

  9. PECAM-1 polymorphism affects monocyte adhesion to endothelial cells.

    Science.gov (United States)

    Goodman, Reyna S; Kirton, Christopher M; Oostingh, Gertie J; Schön, Michael P; Clark, Michael R; Bradley, J Andrew; Taylor, Craig J

    2008-02-15

    Platelet endothelial cell adhesion molecule-1 (PECAM-1/CD31) plays an important role in leukocyte-endothelial cell adhesion and transmigration. Single nucleotide polymorphisms of PECAM-1 encoding amino acid substitutions at positions 98 leucine/valine (L/V), 536 serine/asparagine (S/N), and 643 arginine/glycine (R/G) occur in strong genetic linkage resulting in two common haplotypes (LSR and VNG). These PECAM-1 polymorphisms are associated with graft-versus-host disease after hematopoietic stem cell transplantation and with cardiovascular disease, but whether they influence PECAM-1 function is unknown. We examined the effect of homozygous and heterozygous expression of the PECAM-1 LSR and VNG genotypes on the adhesive interactions of peripheral blood monocytes and activated endothelial cell monolayers under shear stress in a flow-based cell adhesion assay. There was no difference in monocyte adhesion between the two homozygous genotypes of PECAM-1 but when monocytes expressed both alleles in heterozygous form, firm adhesion of monocytes to endothelial cells was markedly increased. PECAM-1 polymorphism expressed in homozygous or heterozygous form by endothelial cells did not influence monocyte adhesion. This is, to our knowledge, the first demonstration that PECAM-1 genotype can alter the level of monocyte binding to endothelial cells and a demonstration that heterozygous expression of a polymorphic protein may lead to altered function.

  10. Adhesion

    Science.gov (United States)

    ... Supplements Videos & Tools Español You Are Here: Home → Medical Encyclopedia → Adhesion URL of this page: //medlineplus.gov/ency/article/001493.htm Adhesion To use the sharing features on this page, please enable JavaScript. Adhesions are bands of scar-like tissue that form between two ...

  11. Physically based principles of cell adhesion mechanosensitivity in tissues

    International Nuclear Information System (INIS)

    Ladoux, Benoit; Nicolas, Alice

    2012-01-01

    The minimal structural unit that defines living organisms is a single cell. By proliferating and mechanically interacting with each other, cells can build complex organization such as tissues that ultimately organize into even more complex multicellular living organisms, such as mammals, composed of billions of single cells interacting with each other. As opposed to passive materials, living cells actively respond to the mechanical perturbations occurring in their environment. Tissue cell adhesion to its surrounding extracellular matrix or to neighbors is an example of a biological process that adapts to physical cues. The adhesion of tissue cells to their surrounding medium induces the generation of intracellular contraction forces whose amplitude adapts to the mechanical properties of the environment. In turn, solicitation of adhering cells with physical forces, such as blood flow shearing the layer of endothelial cells in the lumen of arteries, reinforces cell adhesion and impacts cell contractility. In biological terms, the sensing of physical signals is transduced into biochemical signaling events that guide cellular responses such as cell differentiation, cell growth and cell death. Regarding the biological and developmental consequences of cell adaptation to mechanical perturbations, understanding mechanotransduction in tissue cell adhesion appears as an important step in numerous fields of biology, such as cancer, regenerative medicine or tissue bioengineering for instance. Physicists were first tempted to view cell adhesion as the wetting transition of a soft bag having a complex, adhesive interaction with the surface. But surprising responses of tissue cell adhesion to mechanical cues challenged this view. This, however, did not exclude that cell adhesion could be understood in physical terms. It meant that new models and descriptions had to be created specifically for these biological issues, and could not straightforwardly be adapted from dead matter

  12. Bacterial Vaginosis Bacterial and Epithelial Cell Adhesion Molecules

    Directory of Open Access Journals (Sweden)

    Şayeste Demirezen

    2016-05-01

    molecules. The most important adhesion molecules of epithelium are cadherins, fibronectins, Toll like receptors and carbohydrates. In bacteria, pilis, lypopolysaccaharide and biofilm have primary importance. In this review, the adhesion molecules are discussed in detail and their roles in formation of clue cell are clarified.

  13. Adhesive Micropatterns for Cells: A Microcontact Printing Protocol

    OpenAIRE

    sprotocols

    2014-01-01

    Authors: Manuel Théry and Matthieu Piel Corresponding authors ([](); []()) ### INTRODUCTION This protocol describes a simple, fast, and efficient method for making adhesive micropatterns that can be used to control individual cell shape and adhesion patterns. It is based on the use of an elastomeric stamp containing microfeatures to print proteins on the substrate of choice. The process can be subdiv...

  14. Functionalization of CoCr surfaces with cell adhesive peptides to promote HUVECs adhesion and proliferation

    Energy Technology Data Exchange (ETDEWEB)

    Castellanos, Maria Isabel, E-mail: maria.isabel.castellanos@upc.edu [Biomaterials, Biomechanics and Tissue Engineering Group, Department of Materials Science and Metallurgical Engineering, Technical University of Catalonia (UPC), ETSEIB, 08028 Barcelona (Spain); Centre for Research in Nanoengineering (CRNE), UPC, 08028 Barcelona (Spain); Mas-Moruno, Carlos, E-mail: carles.mas.moruno@upc.edu [Biomaterials, Biomechanics and Tissue Engineering Group, Department of Materials Science and Metallurgical Engineering, Technical University of Catalonia (UPC), ETSEIB, 08028 Barcelona (Spain); Centre for Research in Nanoengineering (CRNE), UPC, 08028 Barcelona (Spain); Grau, Anna, E-mail: agraugar@gmail.com [Biomaterials, Biomechanics and Tissue Engineering Group, Department of Materials Science and Metallurgical Engineering, Technical University of Catalonia (UPC), ETSEIB, 08028 Barcelona (Spain); Centre for Research in Nanoengineering (CRNE), UPC, 08028 Barcelona (Spain); Serra-Picamal, Xavier, E-mail: xserrapicamal@gmail.com [Institute for Bioengineering of Catalonia (IBEC), 08028 Barcelona (Spain); University of Barcelona and CIBER-BBN, 08036 Barcelona (Spain); Institució Catalana de Recerca i Estudis Avançats (ICREA), 08010 Barcelona (Spain); Trepat, Xavier, E-mail: xtrepat@ub.edu [Institute for Bioengineering of Catalonia (IBEC), 08028 Barcelona (Spain); University of Barcelona and CIBER-BBN, 08036 Barcelona (Spain); Institució Catalana de Recerca i Estudis Avançats (ICREA), 08010 Barcelona (Spain); Albericio, Fernando, E-mail: fernando.albericio@irbbarcelona.org [Department of Chemistry, University of Barcelona, CIBER-BBN, 08028 Barcelona (Spain); Joner, Michael, E-mail: michaeljoner@me.com [Department of Cardiology, Deutsches Herzzentrum München, 80636 Munich (Germany); CVPath Institute, Gaithersburg, MD 20878 (United States); and others

    2017-01-30

    Highlights: • We immobilized peptides on CoCr alloy through physisorption and covalent bonding. • Surface activation is an essential step prior to silanization to enhance peptide attachment. • Biofunctionalized surface characteristics were discussed. • RGDS, YIGSR and combination peptides display an improved HUVECs adhesion and proliferation. - Abstract: Biomimetic surface modification with peptides that have specific cell-binding moieties is a promising approach to improve endothelialization of metal-based stents. In this study, we functionalized CoCr surfaces with RGDS, REDV, YIGSR peptides and their combinations to promote endothelial cells (ECs) adhesion and proliferation. An extensive characterization of the functionalized surfaces was performed by XPS analysis, surface charge and quartz crystal microbalance with dissipation monitoring (QCM-D), which demonstrated the successful immobilization of the peptides to the surface. Cell studies demonstrated that the covalent functionalization of CoCr surfaces with an equimolar combination of RGDS and YIGSR represents the most powerful strategy to enhance the early stages of ECs adhesion and proliferation, indicating a positive synergistic effect between the two peptide motifs. Although these peptide sequences slightly increased smooth muscle cells (SMCs) adhesion, these values were ten times lower than those observed for ECs. The combination of RGDS with the REDV sequence did not show synergistic effects in promoting the adhesion or proliferation of ECs. The strategy presented in this study holds great potential to overcome clinical limitations of current metal stents by enhancing their capacity to support surface endothelialization.

  15. Adhesion of mesenchymal stem cells to biomimetic polymers: A review

    Energy Technology Data Exchange (ETDEWEB)

    Shotorbani, Behnaz Banimohamad [Research Institute for Fundamental Sciences (RIFS), University of Tabriz, Tabriz (Iran, Islamic Republic of); Alizadeh, Effat, E-mail: Alizadehe@tbzmed.ac.ir [Department of Medical Biotechnology, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz (Iran, Islamic Republic of); Drug Applied Research Center and Faculty of advanced Medical Science, Tabriz University of Medical Sciences, Tabriz (Iran, Islamic Republic of); The Umbilical Cord Stem Cell Research Center (UCSRC), Tabriz University of Medical Sciences, Tabriz (Iran, Islamic Republic of); Salehi, Roya [Department of Medical Biotechnology, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz (Iran, Islamic Republic of); Drug Applied Research Center and Faculty of advanced Medical Science, Tabriz University of Medical Sciences, Tabriz (Iran, Islamic Republic of); The Umbilical Cord Stem Cell Research Center (UCSRC), Tabriz University of Medical Sciences, Tabriz (Iran, Islamic Republic of); Barzegar, Abolfazl [Research Institute for Fundamental Sciences (RIFS), University of Tabriz, Tabriz (Iran, Islamic Republic of); Department of Medical Biotechnology, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz (Iran, Islamic Republic of)

    2017-02-01

    The mesenchymal stem cells (MSCs) are promising candidates for cell therapy due to the self-renewal, multi-potency, ethically approved state and suitability for autologous transplantation. However, key issue for isolation and manipulation of MSCs is adhesion in ex-vivo culture systems. Biomaterials engineered for mimicking natural extracellular matrix (ECM) conditions which support stem cell adhesion, proliferation and differentiation represent a main area of research in tissue engineering. Some of them successfully enhanced cells adhesion and proliferation because of their biocompatibility, biomimetic texture, and chemistry. However, it is still in its infancy, therefore intensification and optimization of in vitro, in vivo, and preclinical studies is needed to clarify efficacies as well as applicability of those bioengineered constructs. The aim of this review is to discuss mechanisms related to the in-vitro adhesion of MSCs, surfaces biochemical, biophysical, and other factors (of cell's natural and artificial micro-environment) which could affect it and a review of previous research attempting for its bio-chemo-optimization. - Highlights: • The main materials utilized for fabrication of biomimetic polymers are presented. • MSCs cell-material adhesion mechanism and involved molecules are reviewed. • Surface modifications of polymers in terms of MSC adhesion improving are discussed.

  16. Single-cell force spectroscopy of pili-mediated adhesion

    Science.gov (United States)

    Sullan, Ruby May A.; Beaussart, Audrey; Tripathi, Prachi; Derclaye, Sylvie; El-Kirat-Chatel, Sofiane; Li, James K.; Schneider, Yves-Jacques; Vanderleyden, Jos; Lebeer, Sarah; Dufrêne, Yves F.

    2013-12-01

    Although bacterial pili are known to mediate cell adhesion to a variety of substrates, the molecular interactions behind this process are poorly understood. We report the direct measurement of the forces guiding pili-mediated adhesion, focusing on the medically important probiotic bacterium Lactobacillus rhamnosus GG (LGG). Using non-invasive single-cell force spectroscopy (SCFS), we quantify the adhesion forces between individual bacteria and biotic (mucin, intestinal cells) or abiotic (hydrophobic monolayers) surfaces. On hydrophobic surfaces, bacterial pili strengthen adhesion through remarkable nanospring properties, which - presumably - enable the bacteria to resist high shear forces under physiological conditions. On mucin, nanosprings are more frequent and adhesion forces larger, reflecting the influence of specific pili-mucin bonds. Interestingly, these mechanical responses are no longer observed on human intestinal Caco-2 cells. Rather, force curves exhibit constant force plateaus with extended ruptures reflecting the extraction of membrane nanotethers. These single-cell analyses provide novel insights into the molecular mechanisms by which piliated bacteria colonize surfaces (nanosprings, nanotethers), and offer exciting avenues in nanomedicine for understanding and controlling the adhesion of microbial cells (probiotics, pathogens).

  17. Adhesion of mesenchymal stem cells to biomimetic polymers: A review

    International Nuclear Information System (INIS)

    Shotorbani, Behnaz Banimohamad; Alizadeh, Effat; Salehi, Roya; Barzegar, Abolfazl

    2017-01-01

    The mesenchymal stem cells (MSCs) are promising candidates for cell therapy due to the self-renewal, multi-potency, ethically approved state and suitability for autologous transplantation. However, key issue for isolation and manipulation of MSCs is adhesion in ex-vivo culture systems. Biomaterials engineered for mimicking natural extracellular matrix (ECM) conditions which support stem cell adhesion, proliferation and differentiation represent a main area of research in tissue engineering. Some of them successfully enhanced cells adhesion and proliferation because of their biocompatibility, biomimetic texture, and chemistry. However, it is still in its infancy, therefore intensification and optimization of in vitro, in vivo, and preclinical studies is needed to clarify efficacies as well as applicability of those bioengineered constructs. The aim of this review is to discuss mechanisms related to the in-vitro adhesion of MSCs, surfaces biochemical, biophysical, and other factors (of cell's natural and artificial micro-environment) which could affect it and a review of previous research attempting for its bio-chemo-optimization. - Highlights: • The main materials utilized for fabrication of biomimetic polymers are presented. • MSCs cell-material adhesion mechanism and involved molecules are reviewed. • Surface modifications of polymers in terms of MSC adhesion improving are discussed.

  18. The FRIABLE1 gene product affects cell adhesion in Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Lutz Neumetzler

    Full Text Available Cell adhesion in plants is mediated predominantly by pectins, a group of complex cell wall associated polysaccharides. An Arabidopsis mutant, friable1 (frb1, was identified through a screen of T-DNA insertion lines that exhibited defective cell adhesion. Interestingly, the frb1 plants displayed both cell and organ dissociations and also ectopic defects in organ separation. The FRB1 gene encodes a Golgi-localized, plant specific protein with only weak sequence similarities to known proteins (DUF246. Unlike other cell adhesion deficient mutants, frb1 mutants do not have reduced levels of adhesion related cell wall polymers, such as pectins. Instead, FRB1 affects the abundance of galactose- and arabinose-containing oligosaccharides in the Golgi. Furthermore, frb1 mutants displayed alteration in pectin methylesterification, cell wall associated extensins and xyloglucan microstructure. We propose that abnormal FRB1 action has pleiotropic consequences on wall architecture, affecting both the extensin and pectin matrices, with consequent changes to the biomechanical properties of the wall and middle lamella, thereby influencing cell-cell adhesion.

  19. EMMPRIN regulates cytoskeleton reorganization and cell adhesion in prostate cancer.

    Science.gov (United States)

    Zhu, Haining; Zhao, Jun; Zhu, Beibei; Collazo, Joanne; Gal, Jozsef; Shi, Ping; Liu, Li; Ström, Anna-Lena; Lu, Xiaoning; McCann, Richard O; Toborek, Michal; Kyprianou, Natasha

    2012-01-01

    Proteins on cell surface play important roles during cancer progression and metastasis via their ability to mediate cell-to-cell interactions and navigate the communication between cells and the microenvironment. In this study a targeted proteomic analysis was conducted to identify the differential expression of cell surface proteins in human benign (BPH-1) versus malignant (LNCaP and PC-3) prostate epithelial cells. We identified EMMPRIN (extracellular matrix metalloproteinase inducer) as a key candidate and shRNA functional approaches were subsequently applied to determine the role of EMMPRIN in prostate cancer cell adhesion, migration, invasion as well as cytoskeleton organization. EMMPRIN was found to be highly expressed on the surface of prostate cancer cells compared to BPH-1 cells, consistent with a correlation between elevated EMMPRIN and metastasis found in other tumors. No significant changes in cell proliferation, cell cycle progression, or apoptosis were detected in EMMPRIN knockdown cells compared to the scramble controls. Furthermore, EMMPRIN silencing markedly decreased the ability of PC-3 cells to form filopodia, a critical feature of invasive behavior, while it increased expression of cell-cell adhesion and gap junction proteins. Our results suggest that EMMPRIN regulates cell adhesion, invasion, and cytoskeleton reorganization in prostate cancer cells. This study identifies a new function for EMMPRIN as a contributor to prostate cancer cell-cell communication and cytoskeleton changes towards metastatic spread, and suggests its potential value as a marker of prostate cancer progression to metastasis. Copyright © 2011 Wiley Periodicals, Inc.

  20. Quantifying cell adhesion through impingement of a controlled microjet

    NARCIS (Netherlands)

    Visser, C.W.; Gielen, Marise V.; Gielen, Marise Vera; Hao, Zhenxia; le Gac, Severine; Lohse, Detlef; Sun, Chao

    2015-01-01

    The impingement of a submerged, liquid jet onto a cell-covered surface allows assessing cell attachment on surfaces in a straightforward and quantitative manner and in real time, yielding valuable information on cell adhesion. However, this approach is insufficiently characterized for reliable and

  1. Epithelial cell adhesion molecule - More than a carcinoma marker and adhesion molecule

    NARCIS (Netherlands)

    Trzpis, Monika; McLaughlin, Pamela M. J.; de Leij, Lou M. F. H.; Harmsen, Martin C.

    The epithetial cell adhesion molecule (EpCAM, CD326) is a glycoprotein of similar to 40 kd that was originally identified as a marker for carcinoma, attributable to its high expression on rapidly proliferating tumors of epithelial origin. Normal epithelia express EpCAM at a variable but generally

  2. Vaginal epithelial cells regulate membrane adhesiveness to co-ordinate bacterial adhesion

    NARCIS (Netherlands)

    Younes, Jessica A.; Klappe, Karin; Kok, Jan Willem; Busscher, Henk J.; Reid, Gregor; van der Mei, Henny C.

    Vaginal epithelium is colonized by different bacterial strains and species. The bacterial composition of vaginal biofilms controls the balance between health and disease. Little is known about the relative contribution of the epithelial and bacterial cell surfaces to bacterial adhesion and whether

  3. Amphiphilic cationic peptides mediate cell adhesion to plastic surfaces.

    Science.gov (United States)

    Rideout, D C; Lambert, M; Kendall, D A; Moe, G R; Osterman, D G; Tao, H P; Weinstein, I B; Kaiser, E T

    1985-09-01

    Four amphiphilic peptides, each with net charges of +2 or more at neutrality and molecular weights under 4 kilodaltons, were found to mediate the adhesion of normal rat kidney fibroblasts to polystyrene surfaces. Two of these peptides, a model for calcitonin (peptide 1, MCT) and melittin (peptide 2, MEL), form amphiphilic alpha-helical structures at aqueous/nonpolar interfaces. The other two, a luteinizing hormone-releasing hormone model (peptide 3, LHM) and a platelet factor model (peptide 4, MPF) form beta-strand structures in amphiphilic environments. Although it contains only 10 residues, LHM mediated adhesion to surfaces coated with solutions containing as little as 10 pmoles/ml of peptide. All four of these peptides were capable of forming monolayers at air-buffer interfaces with collapse pressures greater than 20 dynes/cm. None of these four peptides contains the tetrapeptide sequence Arg-Gly-Asp-Ser, which has been associated with fibronectin-mediated cell adhesion. Ten polypeptides that also lacked the sequence Arg-Gly-Asp-Ser but were nonamphiphilic and/or had net charges less than +2 at neutrality were all incapable of mediating cell adhesion (Pierschbacher and Ruoslahti, 1984). The morphologies of NRK cells spread on polystyrene coated with peptide LHM resemble the morphologies on fibronectin-coated surfaces, whereas cells spread on surfaces coated with MCT or MEL exhibit strikingly different morphologies. The adhesiveness of MCT, MEL, LHM, and MPF implies that many amphiphilic cationic peptides could prove useful as well defined adhesive substrata for cell culture and for studies of the mechanism of cell adhesion.

  4. Allogeneic hematopoietic stem-cell transplantation for leukocyte adhesion deficiency

    DEFF Research Database (Denmark)

    Qasim, Waseem; Cavazzana-Calvo, Marina; Davies, E Graham

    2009-01-01

    OBJECTIVES: Leukocyte adhesion deficiency is a rare primary immune disorder caused by defects of the CD18 beta-integrin molecule on immune cells. The condition usually presents in early infancy and is characterized by deep tissue infections, leukocytosis with impaired formation of pus, and delayed...... of leukocyte adhesion deficiency who underwent hematopoietic stem-cell transplantation between 1993 and 2007 was retrospectively analyzed. Data were collected by the registries of the European Society for Immunodeficiencies/European Group for Blood and Marrow Transplantation, and the Center for International......, with full donor engraftment in 17 cases, mixed multilineage chimerism in 7 patients, and mononuclear cell-restricted chimerism in an additional 3 cases. CONCLUSIONS: Hematopoietic stem-cell transplantation offers long-term benefit in leukocyte adhesion deficiency and should be considered as an early...

  5. Cell Adhesion Molecules and Ubiquitination—Functions and Significance

    Science.gov (United States)

    Homrich, Mirka; Gotthard, Ingo; Wobst, Hilke; Diestel, Simone

    2015-01-01

    Cell adhesion molecules of the immunoglobulin (Ig) superfamily represent the biggest group of cell adhesion molecules. They have been analyzed since approximately 40 years ago and most of them have been shown to play a role in tumor progression and in the nervous system. All members of the Ig superfamily are intensively posttranslationally modified. However, many aspects of their cellular functions are not yet known. Since a few years ago it is known that some of the Ig superfamily members are modified by ubiquitin. Ubiquitination has classically been described as a proteasomal degradation signal but during the last years it became obvious that it can regulate many other processes including internalization of cell surface molecules and lysosomal sorting. The purpose of this review is to summarize the current knowledge about the ubiquitination of cell adhesion molecules of the Ig superfamily and to discuss its potential physiological roles in tumorigenesis and in the nervous system. PMID:26703751

  6. Opto-acoustic microscopy reveals adhesion mechanics of single cells

    Science.gov (United States)

    Abi Ghanem, Maroun; Dehoux, Thomas; Liu, Liwang; Le Saux, Guillaume; Plawinski, Laurent; Durrieu, Marie-Christine; Audoin, Bertrand

    2018-01-01

    Laser-generated GHz-ultrasonic-based technologies have shown the ability to image single cell adhesion and stiffness simultaneously. Using this new modality, we here demonstrate quantitative indicators to investigate contact mechanics and adhesion processes of the cell. We cultured human cells on a rigid substrate, and we used an inverted pulsed opto-acoustic microscope to generate acoustic pulses containing frequencies up to 100 GHz in the substrate. We map the reflection of the acoustic pulses at the cell-substrate interface to obtain images of the acoustic impedance of the cell, Zc, as well as of the stiffness of the interface, K, with 1 μm lateral resolution. Our results show that the standard deviation ΔZc reveals differences between different cell types arising from the multiplicity of local conformations within the nucleus. From the distribution of K-values within the nuclear region, we extract a mean interfacial stiffness, Km, that quantifies the average contact force in areas of the cell displaying weak bonding. By analogy with classical contact mechanics, we also define the ratio of the real to nominal contact areas, Sr/St. We show that Km can be interpreted as a quantitative indicator of passive contact at metal-cell interfaces, while Sr/St is sensitive to active adhesive processes in the nuclear region. The ability to separate the contributions of passive and active adhesion processes should allow gaining insight into cell-substrate interactions, with important applications in tissue engineering.

  7. Prostaglandins in Cancer Cell Adhesion, Migration, and Invasion

    Directory of Open Access Journals (Sweden)

    David G. Menter

    2012-01-01

    Full Text Available Prostaglandins exert a profound influence over the adhesive, migratory, and invasive behavior of cells during the development and progression of cancer. Cyclooxygenase-2 (COX-2 and microsomal prostaglandin E2 synthase-1 (mPGES-1 are upregulated in inflammation and cancer. This results in the production of prostaglandin E2 (PGE2, which binds to and activates G-protein-coupled prostaglandin E1-4 receptors (EP1-4. Selectively targeting the COX-2/mPGES-1/PGE2/EP1-4 axis of the prostaglandin pathway can reduce the adhesion, migration, invasion, and angiogenesis. Once stimulated by prostaglandins, cadherin adhesive connections between epithelial or endothelial cells are lost. This enables cells to invade through the underlying basement membrane and extracellular matrix (ECM. Interactions with the ECM are mediated by cell surface integrins by “outside-in signaling” through Src and focal adhesion kinase (FAK and/or “inside-out signaling” through talins and kindlins. Combining the use of COX-2/mPGES-1/PGE2/EP1-4 axis-targeted molecules with those targeting cell surface adhesion receptors or their downstream signaling molecules may enhance cancer therapy.

  8. Cell-substrate impedance fluctuations of single amoeboid cells encode cell-shape and adhesion dynamics.

    Science.gov (United States)

    Leonhardt, Helmar; Gerhardt, Matthias; Höppner, Nadine; Krüger, Kirsten; Tarantola, Marco; Beta, Carsten

    2016-01-01

    We show systematic electrical impedance measurements of single motile cells on microelectrodes. Wild-type cells and mutant strains were studied that differ in their cell-substrate adhesion strength. We recorded the projected cell area by time-lapse microscopy and observed irregular oscillations of the cell shape. These oscillations were correlated with long-term variations in the impedance signal. Superposed to these long-term trends, we observed fluctuations in the impedance signal. Their magnitude clearly correlated with the adhesion strength, suggesting that strongly adherent cells display more dynamic cell-substrate interactions.

  9. Cell-substrate impedance fluctuations of single amoeboid cells encode cell-shape and adhesion dynamics

    Science.gov (United States)

    Leonhardt, Helmar; Gerhardt, Matthias; Höppner, Nadine; Krüger, Kirsten; Tarantola, Marco; Beta, Carsten

    2016-01-01

    We show systematic electrical impedance measurements of single motile cells on microelectrodes. Wild-type cells and mutant strains were studied that differ in their cell-substrate adhesion strength. We recorded the projected cell area by time-lapse microscopy and observed irregular oscillations of the cell shape. These oscillations were correlated with long-term variations in the impedance signal. Superposed to these long-term trends, we observed fluctuations in the impedance signal. Their magnitude clearly correlated with the adhesion strength, suggesting that strongly adherent cells display more dynamic cell-substrate interactions.

  10. Cytotoxicity of four denture adhesives on human gingival fibroblast cells.

    Science.gov (United States)

    Lee, Yoon; Ahn, Jin-Soo; Yi, Young-Ah; Chung, Shin-Hye; Yoo, Yeon-Jee; Ju, Sung-Won; Hwang, Ji-Yun; Seo, Deog-Gyu

    2015-02-01

    The purpose of this study was to compare the cytotoxicity of four denture adhesives on human gingival fibroblast cells. Immortalized human gingival fibroblasts were cultured with one of four different denture adhesives, Polident, Protefix, Staydent or Denfix-A, which was placed in insert dishes (10% w/v concentration) for 48 h. The MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay and flow cytometric apoptosis assay were used to evaluate cell viability and apoptosis rates. The fibroblasts were also examined under a scanning electron microscope. The MTT assay showed that all denture adhesives resulted in a significantly lower cell viability compared to the control cells propagated in normal culture medium (p 0.05). Staydent showed the highest apoptosis rate. Scanning electron microscopy showed that the cells of the Staydent group underwent cytoplasmic membrane shrinkage, with cell free areas containing residual fragments of the membrane of dead cells. The four denture adhesives evaluated in this study imparted cytotoxic effects on human gingival fibroblast cells. Staydent showed the highest toxicity.

  11. Quantitative measurement of changes in adhesion force involving focal adhesion kinase during cell attachment, spread, and migration

    International Nuclear Information System (INIS)

    Wu, C.-C.; Su, H.-W.; Lee, C.-C.; Tang, M.-J.; Su, F.-C.

    2005-01-01

    Focal adhesion kinase (FAK) is a critical protein for the regulation of integrin-mediated cellular functions and it can enhance cell motility in Madin-Darby canine kidney (MDCK) cells by hepatocyte growth factor (HGF) induction. We utilized optical trapping and cytodetachment techniques to measure the adhesion force between pico-Newton and nano-Newton (nN) for quantitatively investigating the effects of FAK on adhesion force during initial binding (5 s), beginning of spreading (30 min), spreadout (12 h), and migration (induced by HGF) in MDCK cells with overexpressed FAK (FAK-WT), FAK-related non-kinase (FRNK), as well as normal control cells. Optical tweezers was used to measure the initial binding force between a trapped cell and glass coverslide or between a trapped bead and a seeded cell. In cytodetachment, the commercial atomic force microscope probe with an appropriate spring constant was used as a cyto-detacher to evaluate the change of adhesion force between different FAK expression levels of cells in spreading, spreadout, and migrating status. The results demonstrated that FAK-WT significantly increased the adhesion forces as compared to FRNK cells throughout all the different stages of cell adhesion. For cells in HGF-induced migration, the adhesion force decreased to almost the same level (∼600 nN) regardless of FAK levels indicating that FAK facilitates cells to undergo migration by reducing the adhesion force. Our results suggest FAK plays a role of enhancing cell adhesive ability in the binding and spreading, but an appropriate level of adhesion force is required for HGF-induced cell migration

  12. Adhesion signaling promotes protease‑driven polyploidization of glioblastoma cells.

    Science.gov (United States)

    Mercapide, Javier; Lorico, Aurelio

    2014-11-01

    An increase in ploidy (polyploidization) causes genomic instability in cancer. However, the determinants for the increased DNA content of cancer cells have not yet been fully elucidated. In the present study, we investigated whether adhesion induces polyploidization in human U87MG glioblastoma cells. For this purpose, we employed expression vectors that reported transcriptional activation by signaling networks implicated in cancer. Signaling activation induced by intercellular integrin binding elicited both extracellular signal‑regulated kinase (ERK) and Notch target transcription. Upon the prolonged activation of both ERK and Notch target transcription induced by integrin binding to adhesion protein, cell cultures accumulated polyploid cells, as determined by cell DNA content distribution analysis and the quantification of polynucleated cells. This linked the transcriptional activation induced by integrin adhesion to the increased frequency of polyploidization. Accordingly, the inhibition of signaling decreased the extent of polyploidization mediated by protease‑driven intracellular invasion. Therefore, the findings of this study indicate that integrin adhesion induces polyploidization through the stimulation of glioblastoma cell invasiveness.

  13. Proteoglycans, ion channels and cell-matrix adhesion

    DEFF Research Database (Denmark)

    Mitsou, Ioli; Multhaupt, Hinke A.B.; Couchman, John R.

    2017-01-01

    , maintenance, repair and disease.The cytoplasmic domains of syndecans, while having no intrinsic kinase activity, can nevertheless signal through binding proteins.All syndecans appear to be connected to the actin cytoskeleton and can therefore contribute to cell adhesion, notably to the ECM and migration.......Recent data now suggest that syndecans can regulate stretchactivated ion channels.The structure and function of the syndecans and the ion channels are reviewed here, along with an analysis of ion channel functions in cell-matrix adhesion.This area sheds new light on the syndecans, not least since evidence...

  14. The structure of cell-matrix adhesions: the new frontier.

    Science.gov (United States)

    Hanein, Dorit; Horwitz, Alan Rick

    2012-02-01

    Adhesions between the cell and the extracellular matrix (ECM) are mechanosensitive multi-protein assemblies that transmit force across the cell membrane and regulate biochemical signals in response to the chemical and mechanical environment. These combined functions in force transduction, signaling and mechanosensing contribute to cellular phenotypes that span development, homeostasis and disease. These adhesions form, mature and disassemble in response to actin organization and physical forces that originate from endogenous myosin activity or external forces by the extracellular matrix. Despite advances in our understanding of the protein composition, interactions and regulation, our understanding of matrix adhesion structure and organization, how forces affect this organization, and how these changes dictate specific signaling events is limited. Insights across multiple structural levels are acutely needed to elucidate adhesion structure and ultimately the molecular basis of signaling and mechanotransduction. Here we describe the challenges and recent advances and prospects for unraveling the structure of cell-matrix adhesions and their response to force. Copyright © 2011 Elsevier Ltd. All rights reserved.

  15. Cell adhesion in Drosophila: versatility of cadherin and integrin complexes during development

    OpenAIRE

    Bulgakova, Natalia A.; Klapholz, Benjamin; Brown, Nicholas H.

    2012-01-01

    We highlight recent progress in understanding cadherin and integrin function in the model organism Drosophila. New functions for these adhesion receptors continue to be discovered in this system, emphasising the importance of cell adhesion within the developing organism and showing that the requirement for cell adhesion changes between cell types. New ways to control adhesion have been discovered, including controlling the expression and recruitment of adhesion components, their posttranslati...

  16. Dystroglycan versatility in cell adhesion: a tale of multiple motifs

    Directory of Open Access Journals (Sweden)

    Winder Steve J

    2010-02-01

    Full Text Available Abstract Dystroglycan is a ubiquitously expressed heterodimeric adhesion receptor. The extracellular α-subunit makes connections with a number of laminin G domain ligands including laminins, agrin and perlecan in the extracellular matrix and the transmembrane β-subunit makes connections to the actin filament network via cytoskeletal linkers including dystrophin, utrophin, ezrin and plectin, depending on context. Originally discovered as part of the dystrophin glycoprotein complex of skeletal muscle, dystroglycan is an important adhesion molecule and signalling scaffold in a multitude of cell types and tissues and is involved in several diseases. Dystroglycan has emerged as a multifunctional adhesion platform with many interacting partners associating with its short unstructured cytoplasmic domain. Two particular hotspots are the cytoplasmic juxtamembrane region and at the very carboxy terminus of dystroglycan. Regions which between them have several overlapping functions: in the juxtamembrane region; a nuclear localisation signal, ezrin/radixin/moesin protein, rapsyn and ERK MAP Kinase binding function, and at the C terminus a regulatory tyrosine governing WW, SH2 and SH3 domain interactions. We will discuss the binding partners for these motifs and how their interactions and regulation can modulate the involvement of dystroglycan in a range of different adhesion structures and functions depending on context. Thus dystroglycan presents as a multifunctional scaffold involved in adhesion and adhesion-mediated signalling with its functions under exquisite spatio-temporal regulation.

  17. Cell adhesion signaling regulates RANK expression in osteoclast precursors.

    Directory of Open Access Journals (Sweden)

    Ayako Mochizuki

    Full Text Available Cells with monocyte/macrophage lineage expressing receptor activator of NF-κB (RANK differentiate into osteoclasts following stimulation with the RANK ligand (RANKL. Cell adhesion signaling is also required for osteoclast differentiation from precursors. However, details of the mechanism by which cell adhesion signals induce osteoclast differentiation have not been fully elucidated. To investigate the participation of cell adhesion signaling in osteoclast differentiation, mouse bone marrow-derived macrophages (BMMs were used as osteoclast precursors, and cultured on either plastic cell culture dishes (adherent condition or the top surface of semisolid methylcellulose gel loaded in culture tubes (non-adherent condition. BMMs cultured under the adherent condition differentiated into osteoclasts in response to RANKL stimulation. However, under the non-adherent condition, the efficiency of osteoclast differentiation was markedly reduced even in the presence of RANKL. These BMMs retained macrophage characteristics including phagocytic function and gene expression profile. Lipopolysaccharide (LPS and tumor necrosis factor -αTNF-α activated the NF-κB-mediated signaling pathways under both the adherent and non-adherent conditions, while RANKL activated the pathways only under the adherent condition. BMMs highly expressed RANK mRNA and protein under the adherent condition as compared to the non-adherent condition. Also, BMMs transferred from the adherent to non-adherent condition showed downregulated RANK expression within 24 hours. In contrast, transferring those from the non-adherent to adherent condition significantly increased the level of RANK expression. Moreover, interruption of cell adhesion signaling by echistatin, an RGD-containing disintegrin, decreased RANK expression in BMMs, while forced expression of either RANK or TNFR-associated factor 6 (TRAF6 in BMMs induced their differentiation into osteoclasts even under the non

  18. Cell division orientation is coupled to cell-cell adhesion by the E-cadherin/LGN complex

    NARCIS (Netherlands)

    Gloerich, Martijn; Bianchini, Julie M.; Siemers, Kathleen A.; Cohen, Daniel J.; Nelson, W. James

    2017-01-01

    Both cell-cell adhesion and oriented cell division play prominent roles in establishing tissue architecture, but it is unclear how they might be coordinated. Here, we demonstrate that the cell-cell adhesion protein E-cadherin functions as an instructive cue for cell division orientation. This is

  19. Adhesion and internalization differences of COM nanocrystals on Vero cells before and after cell damage

    Energy Technology Data Exchange (ETDEWEB)

    Gan, Qiong-Zhi; Sun, Xin-Yuan; Ouyang, Jian-Ming, E-mail: toyjm@jnu.edu.cn

    2016-02-01

    The adhesion and internalization between African green monkey kidney epithelial (Vero) cells (before and after oxidative damage by hydrogen peroxide) and calcium oxalate monohydrate (COM) nanocrystals (97 ± 35 nm) were investigated so as to discuss the molecular and cellular mechanism of kidney stone formation. Scanning electron microscope (SEM) was used to observe the Vero–COM nanocrystal adhesion; the nanocrystal-cell adhesion was evaluated by measuring the content of malonaldehyde (MDA), the activity of superoxide dismutase (SOD), the expression level of cell surface osteopontin (OPN) and the change of Zeta potential. Confocal microscopy and flow cytometry were used for the observation and quantitative analysis of crystal internalization. In the process of adhesion, the cell viability and the SOD activity declined, the MDA content, Zeta potential, and the OPN expression level increased. The adhesive capacity of injured Vero was obviously stronger than normal cells; in addition the injured cells promoted the aggregation of COM nanocrystals. The capacity of normal cells to internalize crystals was obviously stronger than that of injured cells. Cell injury increased adhesive sites on cell surface, thereby facilitating the aggregation of COM nanocrystals and their attachment, which results in enhanced risk of calcium oxalate stone formation. - Graphical abstract: The adhesion and internalization differences between Vero cells before and after oxidative damage and calcium oxalate monohydrate nanocrystals were comparatively studied. - Highlights: • Adhesion capacity of injured Vero cells was stronger than normal cells. • Internalization capacity of injured Vero cells was weaker than normal cells. • Injured cells promoted the aggregation of COM nanocrystals. • COM adhesion could aggravate cell injury in both normal and injured cells.

  20. Pharmacology of cell adhesion molecules of the nervous system

    DEFF Research Database (Denmark)

    Kiryushko, Darya; Bock, Elisabeth; Berezin, Vladimir

    2007-01-01

    Cell adhesion molecules (CAMs) play a pivotal role in the development and maintenance of the nervous system under normal conditions. They also are involved in numerous pathological processes such as inflammation, degenerative disorders, and cancer, making them attractive targets for drug...

  1. Opto-acoustic microscopy reveals adhesion mechanics of single cells.

    Science.gov (United States)

    Abi Ghanem, Maroun; Dehoux, Thomas; Liu, Liwang; Le Saux, Guillaume; Plawinski, Laurent; Durrieu, Marie-Christine; Audoin, Bertrand

    2018-01-01

    Laser-generated GHz-ultrasonic-based technologies have shown the ability to image single cell adhesion and stiffness simultaneously. Using this new modality, we here demonstrate quantitative indicators to investigate contact mechanics and adhesion processes of the cell. We cultured human cells on a rigid substrate, and we used an inverted pulsed opto-acoustic microscope to generate acoustic pulses containing frequencies up to 100 GHz in the substrate. We map the reflection of the acoustic pulses at the cell-substrate interface to obtain images of the acoustic impedance of the cell, Z c , as well as of the stiffness of the interface, K, with 1 μm lateral resolution. Our results show that the standard deviation ΔZ c reveals differences between different cell types arising from the multiplicity of local conformations within the nucleus. From the distribution of K-values within the nuclear region, we extract a mean interfacial stiffness, K m , that quantifies the average contact force in areas of the cell displaying weak bonding. By analogy with classical contact mechanics, we also define the ratio of the real to nominal contact areas, S r /S t . We show that K m can be interpreted as a quantitative indicator of passive contact at metal-cell interfaces, while S r /S t is sensitive to active adhesive processes in the nuclear region. The ability to separate the contributions of passive and active adhesion processes should allow gaining insight into cell-substrate interactions, with important applications in tissue engineering.

  2. Micromechanical and surface adhesive properties of single saccharomyces cerevisiae cells

    Science.gov (United States)

    Farzi, Bahman; Cetinkaya, Cetin

    2017-09-01

    The adhesion and mechanical properties of a biological cell (e.g. cell membrane elasticity and adhesiveness) are often strong indicators for the state of its health. Many existing techniques for determining mechanical properties of cells require direct physical contact with a single cell or a group of cells. Physical contact with the cell can trigger complex mechanotransduction mechanisms, leading to cellular responses, and consequently interfering with measurement accuracy. In the current work, based on ultrasonic excitation and interferometric (optical) motion detection, a non-contact method for characterizing the adhesion and mechanical properties of single cells is presented. It is experimentally demonstrated that the rocking (rigid body) motion and internal vibrational resonance frequencies of a single saccharomyces cerevisiae (SC) (baker’s yeast) cell can be acquired with the current approach, and the Young’s modulus and surface tension of the cell membrane as well as surface adhesion energy can be extracted from the values of these acquired resonance frequencies. The detected resonance frequency ranges for single SC cells include a rocking (rigid body) frequency of 330  ±  70 kHz and two breathing resonance frequencies of 1.53  ±  0.12 and 2.02  ±  0.31 MHz. Based on these values, the average work-of-adhesion of SC cells on a silicon substrate in aqueous medium is extracted, for the first time, as WASC-Si=16.2+/- 3.8 mJ {{m}-2} . Similarly, the surface tension and the Young’s modulus of the SC cell wall are predicted as {{σ }SC}=0.16+/- 0.02 N {{m}-1} and {{E}SC}= 9.20  ±  2.80 MPa, respectively. These results are compared to those reported in the literature by utilizing various methods, and good agreements are found. The current approach eliminates the measurement inaccuracies associated with the physical contact. Exciting and detecting cell dynamics at micro-second time-scales is significantly faster than the

  3. Hybrid cell adhesive material for instant dielectrophoretic cell trapping and long-term cell function assessment.

    Science.gov (United States)

    Reyes, Darwin R; Hong, Jennifer S; Elliott, John T; Gaitan, Michael

    2011-08-16

    Dielectrophoresis (DEP) for cell manipulation has focused, for the most part, on approaches for separation/enrichment of cells of interest. Advancements in cell positioning and immobilization onto substrates for cell culture, either as single cells or as cell aggregates, has benefited from the intensified research efforts in DEP (electrokinetic) manipulation. However, there has yet to be a DEP approach that provides the conditions for cell manipulation while promoting cell function processes such as cell differentiation. Here we present the first demonstration of a system that combines DEP with a hybrid cell adhesive material (hCAM) to allow for cell entrapment and cell function, as demonstrated by cell differentiation into neuronlike cells (NLCs). The hCAM, comprised of polyelectrolytes and fibronectin, was engineered to function as an instantaneous cell adhesive surface after DEP manipulation and to support long-term cell function (cell proliferation, induction, and differentiation). Pluripotent P19 mouse embryonal carcinoma cells flowing within a microchannel were attracted to the DEP electrode surface and remained adhered onto the hCAM coating under a fluid flow field after the DEP forces were removed. Cells remained viable after DEP manipulation for up to 8 d, during which time the P19 cells were induced to differentiate into NLCs. This approach could have further applications in areas such as cell-cell communication, three-dimensional cell aggregates to create cell microenvironments, and cell cocultures.

  4. Hypertonic saline impedes tumor cell-endothelial cell interaction by reducing adhesion molecule and laminin expression.

    LENUS (Irish Health Repository)

    Shields, Conor J

    2012-02-03

    BACKGROUND: Hypertonic saline infusion dampens inflammatory responses and suppresses neutrophil-endothelial interaction by reducing adhesion molecule expression. This study tested the hypothesis that hypertonic saline attenuates tumor cell adhesion to the endothelium through a similar mechanism. METHODS: Human colon cancer cells (LS174T) were transfected with green fluorescent protein and exposed to lipopolysaccharide, tumor necrosis factor-alpha, and interleukin-6 under hypertonic and isotonic conditions for 1 and 4 hours. Confluent human umbilical vein endothelial cells were similarly exposed. Cellular apoptosis and expression of adhesion molecules and laminin were measured by flow cytometry. Tumor cell adhesion to endothelium and laminin was assessed with fluorescence microscopy. Data are represented as mean +\\/- standard error of mean, and an ANOVA test was performed to gauge statistical significance, with P <.05 considered significant. RESULTS: Hypertonic exposure significantly reduced tumor cell adhesion despite the presence of the perioperative cell stressors (42 +\\/- 2.9 vs 172.5 +\\/- 12.4, P <.05), attenuated tumor cell beta-1 integrin (14.43 vs 23.84, P <.05), and endothelial cell laminin expression (22.78 +\\/- 2.2 vs 33.74 +\\/- 2.4, P <.05), but did not significantly alter cell viability. CONCLUSION: Hypertonic saline significantly attenuates tumor cell adhesion to endothelium by inhibiting adhesion molecule and laminin expression. This may halt the metastatic behavior of tumor cells shed at surgery.

  5. A Review of Cell Adhesion Studies for Biomedical and Biological Applications

    Science.gov (United States)

    Ahmad Khalili, Amelia; Ahmad, Mohd Ridzuan

    2015-01-01

    Cell adhesion is essential in cell communication and regulation, and is of fundamental importance in the development and maintenance of tissues. The mechanical interactions between a cell and its extracellular matrix (ECM) can influence and control cell behavior and function. The essential function of cell adhesion has created tremendous interests in developing methods for measuring and studying cell adhesion properties. The study of cell adhesion could be categorized into cell adhesion attachment and detachment events. The study of cell adhesion has been widely explored via both events for many important purposes in cellular biology, biomedical, and engineering fields. Cell adhesion attachment and detachment events could be further grouped into the cell population and single cell approach. Various techniques to measure cell adhesion have been applied to many fields of study in order to gain understanding of cell signaling pathways, biomaterial studies for implantable sensors, artificial bone and tooth replacement, the development of tissue-on-a-chip and organ-on-a-chip in tissue engineering, the effects of biochemical treatments and environmental stimuli to the cell adhesion, the potential of drug treatments, cancer metastasis study, and the determination of the adhesion properties of normal and cancerous cells. This review discussed the overview of the available methods to study cell adhesion through attachment and detachment events. PMID:26251901

  6. A Review of Cell Adhesion Studies for Biomedical and Biological Applications

    Directory of Open Access Journals (Sweden)

    Amelia Ahmad Khalili

    2015-08-01

    Full Text Available Cell adhesion is essential in cell communication and regulation, and is of fundamental importance in the development and maintenance of tissues. The mechanical interactions between a cell and its extracellular matrix (ECM can influence and control cell behavior and function. The essential function of cell adhesion has created tremendous interests in developing methods for measuring and studying cell adhesion properties. The study of cell adhesion could be categorized into cell adhesion attachment and detachment events. The study of cell adhesion has been widely explored via both events for many important purposes in cellular biology, biomedical, and engineering fields. Cell adhesion attachment and detachment events could be further grouped into the cell population and single cell approach. Various techniques to measure cell adhesion have been applied to many fields of study in order to gain understanding of cell signaling pathways, biomaterial studies for implantable sensors, artificial bone and tooth replacement, the development of tissue-on-a-chip and organ-on-a-chip in tissue engineering, the effects of biochemical treatments and environmental stimuli to the cell adhesion, the potential of drug treatments, cancer metastasis study, and the determination of the adhesion properties of normal and cancerous cells. This review discussed the overview of the available methods to study cell adhesion through attachment and detachment events.

  7. Adhesion and migration of cells responding to microtopography.

    Science.gov (United States)

    Estévez, Maruxa; Martínez, Elena; Yarwood, Stephen J; Dalby, Matthew J; Samitier, Josep

    2015-05-01

    It is known that cells respond strongly to microtopography. However, cellular mechanisms of response are unclear. Here, we study wild-type fibroblasts responding to 25 µm(2) posts and compare their response to that of FAK(-/-) fibroblasts and fibroblasts with PMA treatment to stimulate protein kinase C (PKC) and the small g-protein Rac. FAK knockout cells modulated adhesion number and size in a similar way to cells on topography; that is, they used more, smaller adhesions, but migration was almost completely stalled demonstrating the importance of FAK signaling in contact guidance and adhesion turnover. Little similarity, however, was observed to PKC stimulated cells and cells on the topography. Interestingly, with PKC stimulation the cell nuclei became highly deformable bringing focus on these surfaces to the study of metastasis. Surfaces that aid the study of cellular migration are important in developing understanding of mechanisms of wound healing and repair in aligned tissues such as ligament and tendon. © 2014 Wiley Periodicals, Inc.

  8. Understanding dynamic changes in live cell adhesion with neutron reflectometry

    Science.gov (United States)

    Junghans, Ann

    Understanding the structure and functionality of biological systems on a nanometer-resolution and short temporal scales is important for solving complex biological problems, developing innovative treatment, and advancing the design of highly functionalized biomimetic materials. For example, adhesion of cells to an underlying substrate plays a crucial role in physiology and disease development, and has been investigated with great interest for several decades. In the talk, we would like to highlight recent advances in utilizing neutron scattering to study bio-related structures in dynamic conditions (e . g . under the shear flow) including in-situ investigations of the interfacial properties of living cells. The strength of neutron reflectometry is its non-pertubative nature, the ability to probe buried interfaces with nanometer resolution and its sensitivity to light elements like hydrogen and carbon. That allows us to study details of cell - substrate interfaces that are not accessible with any other standard techniques. We studied the adhesion of human brain tumor cells (U251) to quartz substrates and their responses to the external mechanical forces. Such cells are isolated within the central nervous system which makes them difficult to reach with conventional therapies and therefore making them highly invasive. Our results reveal changes in the thickness and composition of the adhesion layer (a layer between the cell lipid membrane and the quartz substrate), largely composed of hyaluronic acid and associated proteoglycans, when the cells were subjected to shear stress. Further studies will allow us to determine more conditions triggering changes in the composition of the bio-material in the adhesion layer. This, in turn, can help to identify changes that correlate with tumor invasiveness, which can have significant medical impact for the development of targeted anti-invasive therapies.

  9. The Neural Cell Adhesion Molecule NCAM2/OCAM/RNCAM, a Close Relative to NCAM

    DEFF Research Database (Denmark)

    Kulahin, Nikolaj; Walmod, Peter

    2008-01-01

    molecule (NCAM) is a well characterized, ubiquitously expressed CAM that is highly expressed in the nervous system. In addition to mediating cell adhesion, NCAM participates in a multitude of cellular events, including survival, migration, and differentiation of cells, outgrowth of neurites, and formation......Cell adhesion molecules (CAMs) constitute a large class of plasma membrane-anchored proteins that mediate attachment between neighboring cells and between cells and the surrounding extracellular matrix (ECM). However, CAMs are more than simple mediators of cell adhesion. The neural cell adhesion...... and plasticity of synapses. NCAM shares an overall sequence identity of approximately 44% with the neural cell adhesion molecule 2 (NCAM2), a protein also known as olfactory cell adhesion molecule (OCAM) and Rb-8 neural cell adhesion molecule (RNCAM), and the region-for-region sequence homology between the two...

  10. Growth hormone increases vascular cell adhesion molecule 1 expression

    DEFF Research Database (Denmark)

    Hansen, Troels Krarup; Fisker, Sanne; Dall, Rolf

    2004-01-01

    We investigated the impact of GH administration on endothelial adhesion molecules, vascular cell adhesion molecule-1 (VCAM-1) and E-selectin, in vivo and in vitro. Soluble VCAM-1, E-selectin, and C-reactive protein concentrations were measured before and after treatment in 25 healthy subjects...... and 25 adult GH-deficient (GHD) patients randomized to GH treatment or placebo. Furthermore, we studied the direct effect of GH and IGF-I and serum from GH-treated subjects on basal and TNF alpha-stimulated expression of VCAM-1 and E-selectin on cultured human umbilical vein endothelial cells. Baseline......% confidence interval: 95.0-208.7 microg/liter); P cells, there was no direct stimulatory effect of either GH or IGF-I on the expression of VCAM-1 and E-selectin, but serum from GH-treated healthy subjects significantly increased the expression of VCAM-1 (P

  11. RNA-binding IMPs promote cell adhesion and invadopodia formation

    DEFF Research Database (Denmark)

    Vikesaa, Jonas; Hansen, Thomas V O; Jønson, Lars

    2006-01-01

    Oncofetal RNA-binding IMPs have been implicated in mRNA localization, nuclear export, turnover and translational control. To depict the cellular actions of IMPs, we performed a loss-of-function analysis, which showed that IMPs are necessary for proper cell adhesion, cytoplasmic spreading and inva......Oncofetal RNA-binding IMPs have been implicated in mRNA localization, nuclear export, turnover and translational control. To depict the cellular actions of IMPs, we performed a loss-of-function analysis, which showed that IMPs are necessary for proper cell adhesion, cytoplasmic spreading...... and invadopodia formation. Loss of IMPs was associated with a coordinate downregulation of mRNAs encoding extracellular matrix and adhesion proteins. The transcripts were present in IMP RNP granules, implying that IMPs were directly involved in the post-transcriptional control of the transcripts. In particular......-mediated invadopodia formation. Taken together, our results indicate that RNA-binding proteins exert profound effects on cellular adhesion and invasion during development and cancer formation....

  12. Rapid and Localized Mechanical Stimulation and Adhesion Assay: TRPM7 Involvement in Calcium Signaling and Cell Adhesion.

    Directory of Open Access Journals (Sweden)

    Wagner Shin Nishitani

    Full Text Available A cell mechanical stimulation equipment, based on cell substrate deformation, and a more sensitive method for measuring adhesion of cells were developed. A probe, precisely positioned close to the cell, was capable of a vertical localized mechanical stimulation with a temporal frequency of 207 Hz, and strain magnitude of 50%. This setup was characterized and used to probe the response of Human Umbilical Endothelial Vein Cells (HUVECs in terms of calcium signaling. The intracellular calcium ion concentration was measured by the genetically encoded Cameleon biosensor, with the Transient Receptor Potential cation channel, subfamily M, member 7 (TRPM7 expression inhibited. As TRPM7 expression also regulates adhesion, a relatively simple method for measuring adhesion of cells was also developed, tested and used to study the effect of adhesion alone. Three adhesion conditions of HUVECs on polyacrylamide gel dishes were compared. In the first condition, the substrate is fully treated with Sulfo-SANPAH crosslinking and fibronectin. The other two conditions had increasingly reduced adhesion: partially treated (only coated with fibronectin, with no use of Sulfo-SANPAH, at 5% of the normal amount and non-treated polyacrylamide gels. The cells showed adhesion and calcium response to the mechanical stimulation correlated to the degree of gel treatment: highest for fully treated gels and lowest for non-treated ones. TRPM7 inhibition by siRNA on HUVECs caused an increase in adhesion relative to control (no siRNA treatment and non-targeting siRNA, but a decrease to 80% of calcium response relative to non-targeting siRNA which confirms the important role of TRPM7 in mechanotransduction despite the increase in adhesion.

  13. Strong adhesion by regulatory T cells induces dendritic cell cytoskeletal polarization and contact-dependent lethargy.

    Science.gov (United States)

    Chen, Jiahuan; Ganguly, Anutosh; Mucsi, Ashley D; Meng, Junchen; Yan, Jiacong; Detampel, Pascal; Munro, Fay; Zhang, Zongde; Wu, Mei; Hari, Aswin; Stenner, Melanie D; Zheng, Wencheng; Kubes, Paul; Xia, Tie; Amrein, Matthias W; Qi, Hai; Shi, Yan

    2017-02-01

    Dendritic cells are targeted by regulatory T (T reg) cells, in a manner that operates as an indirect mode of T cell suppression. In this study, using a combination of single-cell force spectroscopy and structured illumination microscopy, we analyze individual T reg cell-DC interaction events and show that T reg cells exhibit strong intrinsic adhesiveness to DCs. This increased DC adhesion reduces the ability of contacted DCs to engage other antigen-specific cells. We show that this unusually strong LFA-1-dependent adhesiveness of T reg cells is caused in part by their low calpain activities, which normally release integrin-cytoskeleton linkage, and thereby reduce adhesion. Super resolution imaging reveals that such T reg cell adhesion causes sequestration of Fascin-1, an actin-bundling protein essential for immunological synapse formation, and skews Fascin-1-dependent actin polarization in DCs toward the T reg cell adhesion zone. Although it is reversible upon T reg cell disengagement, this sequestration of essential cytoskeletal components causes a lethargic state of DCs, leading to reduced T cell priming. Our results reveal a dynamic cytoskeletal component underlying T reg cell-mediated DC suppression in a contact-dependent manner. © 2017 Chen et al.

  14. Combinational Effect of Cell Adhesion Biomolecules and Their Immobilized Polymer Property to Enhance Cell-Selective Adhesion

    Directory of Open Access Journals (Sweden)

    Rio Kurimoto

    2016-01-01

    Full Text Available Although surface immobilization of medical devices with bioactive molecules is one of the most widely used strategies to improve biocompatibility, the physicochemical properties of the biomaterials significantly impact the activity of the immobilized molecules. Herein we investigate the combinational effects of cell-selective biomolecules and the hydrophobicity/hydrophilicity of the polymeric substrate on selective adhesion of endothelial cells (ECs, fibroblasts (FBs, and smooth muscle cells (SMCs. To control the polymeric substrate, biomolecules are immobilized on thermoresponsive poly(N-isopropylacrylamide-co-2-carboxyisopropylacrylamide (poly(NIPAAm-co-CIPAAm-grafted glass surfaces. By switching the molecular conformation of the biomolecule-immobilized polymers, the cell-selective adhesion performances are evaluated. In case of RGDS (Arg-Gly-Asp-Ser peptide-immobilized surfaces, all cell types adhere well regardless of the surface hydrophobicity. On the other hand, a tri-Arg-immobilized surface exhibits FB-selectivity when the surface is hydrophilic. Additionally, a tri-Ile-immobilized surface exhibits EC-selective cell adhesion when the surface is hydrophobic. We believe that the proposed concept, which is used to investigate the biomolecule-immobilized surface combination, is important to produce new biomaterials, which are highly demanded for medical implants and tissue engineering.

  15. Evaluation of cell responses toward adhesives with different photoinitiating systems.

    Science.gov (United States)

    Van Landuyt, Kirsten L; Krifka, Stephanie; Hiller, Karl-Anton; Bolay, Carola; Waha, Claudia; Van Meerbeek, Bart; Schmalz, Gottfried; Schweikl, Helmut

    2015-08-01

    The photoinitiator diphenyl-(2,4,6-trimethylbenzoyl)phosphine oxide (TPO) is more reactive than a camphorquinone/amine (CQ) system, and TPO-based adhesives obtained a higher degree of conversion (DC) with fewer leached monomers. The hypothesis tested here is that a TPO-based adhesive is less toxic than a CQ-based adhesive. A CQ-based adhesive (SBU-CQ) (Scotchbond Universal, 3M ESPE) and its experimental counterpart with TPO (SBU-TPO) were tested for cytotoxicity in human pulp-derived cells (tHPC). Oxidative stress was analyzed by the generation of reactive oxygen species (ROS) and by the expression of antioxidant enzymes. A dentin barrier test (DBT) was used to evaluate cell viability in simulated clinical circumstances. Unpolymerized SBU-TPO was significantly more toxic than SBU-CQ after a 24h exposure, and TPO alone (EC50=0.06mM) was more cytotoxic than CQ (EC50=0.88mM), EDMAB (EC50=0.68mM) or CQ/EDMAB (EC50=0.50mM). Cultures preincubated with BSO (l-buthionine sulfoximine), an inhibitor of glutathione synthesis, indicated a minor role of glutathione in cytotoxic responses toward the adhesives. Although the generation of ROS was not detected, a differential expression of enzymatic antioxidants revealed that cells exposed to unpolymerized SBU-TPO or SBU-CQ are subject to oxidative stress. Polymerized SBU-TPO was more cytotoxic than SBU-CQ under specific experimental conditions only, but no cytotoxicity was detected in a DBT with a 200μm dentin barrier. Not only DC and monomer-release determine the biocompatibility of adhesives, but also the cytotoxicity of the (photo-)initiator should be taken into account. Addition of TPO rendered a universal adhesive more toxic compared to CQ; however, this effect could be annulled by a thin dentin barrier. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  16. Anandamide inhibits adhesion and migration of breast cancer cells

    International Nuclear Information System (INIS)

    Grimaldi, Claudia; Pisanti, Simona; Laezza, Chiara; Malfitano, Anna Maria; Santoro, Antonietta; Vitale, Mario; Caruso, Maria Gabriella; Notarnicola, Maria; Iacuzzo, Irma; Portella, Giuseppe; Di Marzo, Vincenzo; Bifulco, Maurizio

    2006-01-01

    The endocannabinoid system regulates cell proliferation in human breast cancer cells. We reasoned that stimulation of cannabinoid CB 1 receptors could induce a non-invasive phenotype in breast mtastatic cells. In a model of metastatic spreading in vivo, the metabolically stable anandamide analogue, 2-methyl-2'-F-anandamide (Met-F-AEA), significantly reduced the number and dimension of metastatic nodes, this effect being antagonized by the selective CB 1 antagonist SR141716A. In MDA-MB-231 cells, a highly invasive human breast cancer cell line, and in TSA-E1 cells, a murine breast cancer cell line, Met-F-AEA inhibited adhesion and migration on type IV collagen in vitro without modifying integrin expression: both these effects were antagonized by SR141716A. In order to understand the molecular mechanism involved in these processes, we analyzed the phosphorylation of FAK and Src, two tyrosine kinases involved in migration and adhesion. In Met-F-AEA-treated cells, we observed a decreased tyrosine phosphorylation of both FAK and Src, this effect being attenuated by SR141716A. We propose that CB 1 receptor agonists inhibit tumor cell invasion and metastasis by modulating FAK phosphorylation, and that CB 1 receptor activation might represent a novel therapeutic strategy to slow down the growth of breast carcinoma and to inhibit its metastatic diffusion in vivo

  17. Focal adhesion kinase-dependent focal adhesion recruitment of SH2 domains directs SRC into focal adhesions to regulate cell adhesion and migration.

    Science.gov (United States)

    Wu, Jui-Chung; Chen, Yu-Chen; Kuo, Chih-Ting; Wenshin Yu, Helen; Chen, Yin-Quan; Chiou, Arthur; Kuo, Jean-Cheng

    2015-12-18

    Directed cell migration requires dynamical control of the protein complex within focal adhesions (FAs) and this control is regulated by signaling events involving tyrosine phosphorylation. We screened the SH2 domains present in tyrosine-specific kinases and phosphatases found within FAs, including SRC, SHP1 and SHP2, and examined whether these enzymes transiently target FAs via their SH2 domains. We found that the SRC_SH2 domain and the SHP2_N-SH2 domain are associated with FAs, but only the SRC_SH2 domain is able to be regulated by focal adhesion kinase (FAK). The FAK-dependent association of the SRC_SH2 domain is necessary and sufficient for SRC FA targeting. When the targeting of SRC into FAs is inhibited, there is significant suppression of SRC-mediated phosphorylation of paxillin and FAK; this results in an inhibition of FA formation and maturation and a reduction in cell migration. This study reveals an association between FAs and the SRC_SH2 domain as well as between FAs and the SHP2_N-SH2 domains. This supports the hypothesis that the FAK-regulated SRC_SH2 domain plays an important role in directing SRC into FAs and that this SRC-mediated FA signaling drives cell migration.

  18. Ion implantation induced nanotopography on titanium and bone cell adhesion

    Energy Technology Data Exchange (ETDEWEB)

    Braceras, Iñigo, E-mail: inigo.braceras@tecnalia.com [Tecnalia, Mikeletegi Pasealekua 2, 20009 Donostia-San Sebastian (Spain); CIBER de Bioingeniería, Biomateriales y Nanomedicina (Ciber-BBN) (Spain); Vera, Carolina; Ayerdi-Izquierdo, Ana [Tecnalia, Mikeletegi Pasealekua 2, 20009 Donostia-San Sebastian (Spain); CIBER de Bioingeniería, Biomateriales y Nanomedicina (Ciber-BBN) (Spain); Muñoz, Roberto [Tecnalia, Mikeletegi Pasealekua 2, 20009 Donostia-San Sebastian (Spain); Lorenzo, Jaione; Alvarez, Noelia [Tecnalia, Mikeletegi Pasealekua 2, 20009 Donostia-San Sebastian (Spain); CIBER de Bioingeniería, Biomateriales y Nanomedicina (Ciber-BBN) (Spain); Maeztu, Miguel Ángel de [Private Practice, P° San Francisco, 43 A-1°, 20400 Tolosa (Spain)

    2014-08-15

    Graphical abstract: Titanium surfaces modified by inert ion implantation affect cell adhesion through modification of the nanotopography in the same dimensional range of that of human bone inorganic phases. - Highlights: • Inert ion implantation on Ti modifies surface nanotopography and bone cell adhesion. • Ion implantation can produce nanostructured surfaces on titanium in the very same range as of those of the mineral phase of the human bone. • Appropriate tool for studying the relevance of nanostructured surfaces on bone mineralization and implant osseointegration. • Ion implantation induced nanotopography have a statistically significant influence on bone cell adhesion. - Abstract: Permanent endo-osseous implants require a fast, reliable and consistent osseointegration, i.e. intimate bonding between bone and implant, so biomechanical loads can be safely transferred. Among the parameters that affect this process, it is widely admitted that implant surface topography, surface energy and composition play an important role. Most surface treatments to improve osseointegration focus on micro-scale features, as few can effectively control the effects of the treatment at nanoscale. On the other hand, ion implantation allows controlling such nanofeatures. This study has investigated the nanotopography of titanium, as induced by different ion implantation surface treatments, its similarity with human bone tissue structure and its effect on human bone cell adhesion, as a first step in the process of osseointegration. The effect of ion implantation treatment parameters such as energy (40–80 keV), fluence (1–2 e17 ion/cm{sup 2}) and ion species (Kr, Ar, Ne and Xe) on the nanotopography of medical grade titanium has been measured and assessed by AFM and contact angle. Then, in vitro tests have been performed to assess the effect of these nanotopographies on osteoblast adhesion. The results have shown that the nanostructure of bone and the studied ion implanted

  19. Ion implantation induced nanotopography on titanium and bone cell adhesion

    International Nuclear Information System (INIS)

    Braceras, Iñigo; Vera, Carolina; Ayerdi-Izquierdo, Ana; Muñoz, Roberto; Lorenzo, Jaione; Alvarez, Noelia; Maeztu, Miguel Ángel de

    2014-01-01

    Graphical abstract: Titanium surfaces modified by inert ion implantation affect cell adhesion through modification of the nanotopography in the same dimensional range of that of human bone inorganic phases. - Highlights: • Inert ion implantation on Ti modifies surface nanotopography and bone cell adhesion. • Ion implantation can produce nanostructured surfaces on titanium in the very same range as of those of the mineral phase of the human bone. • Appropriate tool for studying the relevance of nanostructured surfaces on bone mineralization and implant osseointegration. • Ion implantation induced nanotopography have a statistically significant influence on bone cell adhesion. - Abstract: Permanent endo-osseous implants require a fast, reliable and consistent osseointegration, i.e. intimate bonding between bone and implant, so biomechanical loads can be safely transferred. Among the parameters that affect this process, it is widely admitted that implant surface topography, surface energy and composition play an important role. Most surface treatments to improve osseointegration focus on micro-scale features, as few can effectively control the effects of the treatment at nanoscale. On the other hand, ion implantation allows controlling such nanofeatures. This study has investigated the nanotopography of titanium, as induced by different ion implantation surface treatments, its similarity with human bone tissue structure and its effect on human bone cell adhesion, as a first step in the process of osseointegration. The effect of ion implantation treatment parameters such as energy (40–80 keV), fluence (1–2 e17 ion/cm 2 ) and ion species (Kr, Ar, Ne and Xe) on the nanotopography of medical grade titanium has been measured and assessed by AFM and contact angle. Then, in vitro tests have been performed to assess the effect of these nanotopographies on osteoblast adhesion. The results have shown that the nanostructure of bone and the studied ion implanted

  20. Activation of the canonical Wnt/β-catenin pathway enhances monocyte adhesion to endothelial cells

    International Nuclear Information System (INIS)

    Lee, Dong Kun; Nathan Grantham, R.; Trachte, Aaron L.; Mannion, John D.; Wilson, Colleen L.

    2006-01-01

    Monocyte adhesion to vascular endothelium has been reported to be one of the early processes in the development of atherosclerosis. In an attempt to develop strategies to prevent or delay atherosclerosis progression, we analyzed effects of the Wnt/β-catenin signaling pathway on monocyte adhesion to various human endothelial cells. Adhesion of fluorescein-labeled monocytes to various human endothelial cells was analyzed under a fluorescent microscope. Unlike sodium chloride, lithium chloride enhanced monocyte adhesion to endothelial cells in a dose-dependent manner. We further demonstrated that inhibitors for glycogen synthase kinase (GSK)-3β or proteosome enhanced monocyte-endothelial cell adhesion. Results of semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR) indicated that activation of Wnt/β-catenin pathway did not change expression levels of mRNA for adhesion molecules. In conclusion, the canonical Wnt/β-catenin pathway enhanced monocyte-endothelial cell adhesion without changing expression levels of adhesion molecules

  1. Using cell-substrate impedance and live cell imaging to measure real-time changes in cellular adhesion and de-adhesion induced by matrix modification.

    Science.gov (United States)

    Rees, Martin D; Thomas, Shane R

    2015-02-19

    Cell-matrix adhesion plays a key role in controlling cell morphology and signaling. Stimuli that disrupt cell-matrix adhesion (e.g., myeloperoxidase and other matrix-modifying oxidants/enzymes released during inflammation) are implicated in triggering pathological changes in cellular function, phenotype and viability in a number of diseases. Here, we describe how cell-substrate impedance and live cell imaging approaches can be readily employed to accurately quantify real-time changes in cell adhesion and de-adhesion induced by matrix modification (using endothelial cells and myeloperoxidase as a pathophysiological matrix-modifying stimulus) with high temporal resolution and in a non-invasive manner. The xCELLigence cell-substrate impedance system continuously quantifies the area of cell-matrix adhesion by measuring the electrical impedance at the cell-substrate interface in cells grown on gold microelectrode arrays. Image analysis of time-lapse differential interference contrast movies quantifies changes in the projected area of individual cells over time, representing changes in the area of cell-matrix contact. Both techniques accurately quantify rapid changes to cellular adhesion and de-adhesion processes. Cell-substrate impedance on microelectrode biosensor arrays provides a platform for robust, high-throughput measurements. Live cell imaging analyses provide additional detail regarding the nature and dynamics of the morphological changes quantified by cell-substrate impedance measurements. These complementary approaches provide valuable new insights into how myeloperoxidase-catalyzed oxidative modification of subcellular extracellular matrix components triggers rapid changes in cell adhesion, morphology and signaling in endothelial cells. These approaches are also applicable for studying cellular adhesion dynamics in response to other matrix-modifying stimuli and in related adherent cells (e.g., epithelial cells).

  2. Encapsulant Adhesion to Surface Metallization on Photovoltaic Cells

    Energy Technology Data Exchange (ETDEWEB)

    Tracy, Jared; Bosco, Nick; Dauskardt, Reinhold

    2017-11-01

    Delamination of encapsulant materials from PV cell surfaces often appears to originate at regions with metallization. Using a fracture mechanics based metrology, the adhesion of ethylene vinyl acetate (EVA) encapsulant to screen-printed silver metallization was evaluated. At room temperature, the fracture energy Gc [J/m2] of the EVA/silver interface (952 J/m2) was ~70% lower than that of the EVA/antireflective (AR) coating (>2900 J/m2) and ~60% lower than that of the EVA to the surface of cell (2265 J/m2). After only 300 h of damp heat aging, the adhesion energy of the silver interface dropped to and plateaued at ~50-60 J/m2 while that of the EVA/AR coating and EVA/cell remained mostly unchanged. Elemental surface analysis showed that the EVA separates from the silver in a purely adhesive manner, indicating that bonds at the interface were likely displaced in the presence of humidity and chemical byproducts at elevated temperature, which in part accounts for the propensity of metalized surfaces to delaminate in the field.

  3. Cell-substrate interaction with cell-membrane-stress dependent adhesion.

    Science.gov (United States)

    Jiang, H; Yang, B

    2012-01-10

    Cell-substrate interaction is examined in a two-dimensional mechanics model. The cell and substrate are treated as a shell and an elastic solid, respectively. Their interaction through adhesion is treated using nonlinear springs. Compared to previous cell mechanics models, the present model introduces a cohesive force law that is dependent not only on cell-substrate distance but also on internal cell-membrane stress. It is postulated that a living cell would establish focal adhesion sites with density dependent on the cell-membrane stress. The formulated mechanics problem is numerically solved using coupled finite elements and boundary elements for the cell and the substrate, respectively. The nodes in the adhesion zone from either side are linked by the cohesive springs. The specific cases of a cell adhering to a homogeneous substrate and a heterogeneous bimaterial substrate are examined. The analyses show that the substrate stiffness affects the adhesion behavior significantly and regulates the direction of cell adhesion, in good agreement with the experimental results in the literature. By introducing a reactive parameter (i.e., cell-membrane stress) linking biological responses of a living cell to a mechanical environment, the present model offers a unified mechanistic vehicle for characterization and prediction of living cell responses to various kinds of mechanical stimuli including local extracellular matrix and neighboring cells. Copyright © 2011 Elsevier Ltd. All rights reserved.

  4. Inhibition of neuronal cell–cell adhesion measured by the microscopic aggregation assay and impedance sensing

    NARCIS (Netherlands)

    Wiertz, Remy; Marani, Enrico; Rutten, Wim

    2010-01-01

    Microscopic aggregation assay and impedance sensing (IS) were used to monitor a change in in vitro neuron–neuron adhesion in response to blocking of cell adhesion molecules. By blocking neuron–neuron adhesion, migration and aggregation of neuronal cells can be inhibited. This leads to better control

  5. Interlayer adhesion in roll-to-roll processed flexible inverted polymer solar cells

    KAUST Repository

    Dupont, Stephanie R.; Oliver, Mark; Krebs, Frederik C.; Dauskardt, Reinhold H.

    2012-01-01

    The interlayer adhesion of roll-to-roll processed flexible inverted P3HT:PCBM bulk heterojunction (BHJ) polymer solar cells is reported. Poor adhesion between adjacent layers may result in loss of device performance from delamination driven

  6. The Drosophila cell adhesion molecule Neuroglian regulates Lissencephaly-1 localisation in circulating immunosurveillance cells

    Directory of Open Access Journals (Sweden)

    Williams Michael J

    2009-03-01

    Full Text Available Abstract Background When the parasitoid wasp Leptopilina boulardi lays its eggs in Drosophila larvae phagocytic cells called plasmatocytes and specialized cells known as lamellocytes encapsulate the egg. This requires these circulating immunosurveillance cells (haemocytes to change from a non-adhesive to an adhesive state enabling them to bind to the invader. Interestingly, attachment of leukocytes, platelets, and insect haemocytes requires the same adhesion complexes as epithelial and neuronal cells. Results Here evidence is presented showing that the Drosophila L1-type cell adhesion molecule Neuroglian (Nrg is required for haemocytes to encapsulate L. boulardi wasp eggs. The amino acid sequence FIGQY containing a conserved phosphorylated tyrosine is found in the intracellular domain of all L1-type cell adhesion molecules. This conserved tyrosine is phosphorylated at the cell periphery of plasmatocytes and lamellocytes prior to parasitisation, but dephosphorylated after immune activation. Intriguingly, another pool of Nrg located near the nucleus of plasmatocytes remains phosphorylated after parasitisation. In mammalian neuronal cells phosphorylated neurofascin, another L1-type cell adhesion molecule interacts with a nucleokinesis complex containing the microtubule binding protein lissencephaly-1 (Lis1 1. Interestingly in plasmatocytes from Nrg mutants the nucleokinesis regulating protein Lissencephaly-1 (Lis1 fails to localise properly around the nucleus and is instead found diffuse throughout the cytoplasm and at unidentified perinuclear structures. After attaching to the wasp egg control plasmatocytes extend filopodia laterally from their cell periphery; as well as extending lateral filopodia plasmatocytes from Nrg mutants also extend many filopodia from their apical surface. Conclusion The Drosophila cellular adhesion molecule Neuroglian is expressed in haemocytes and its activity is required for the encapsulation of L. boularli eggs. At

  7. ZDHHC3 Tyrosine Phosphorylation Regulates Neural Cell Adhesion Molecule Palmitoylation

    Science.gov (United States)

    Lievens, Patricia Marie-Jeanne; Kuznetsova, Tatiana; Kochlamazashvili, Gaga; Cesca, Fabrizia; Gorinski, Natalya; Galil, Dalia Abdel; Cherkas, Volodimir; Ronkina, Natalia; Lafera, Juri; Gaestel, Matthias

    2016-01-01

    The neural cell adhesion molecule (NCAM) mediates cell-cell and cell-matrix adhesion. It is broadly expressed in the nervous system and regulates neurite outgrowth, synaptogenesis, and synaptic plasticity. Previous in vitro studies revealed that palmitoylation of NCAM is required for fibroblast growth factor 2 (FGF2)-stimulated neurite outgrowth and identified the zinc finger DHHC (Asp-His-His-Cys)-containing proteins ZDHHC3 and ZDHHC7 as specific NCAM-palmitoylating enzymes. Here, we verified that FGF2 controlled NCAM palmitoylation in vivo and investigated molecular mechanisms regulating NCAM palmitoylation by ZDHHC3. Experiments with overexpression and pharmacological inhibition of FGF receptor (FGFR) and Src revealed that these kinases control tyrosine phosphorylation of ZDHHC3 and that ZDHHC3 is phosphorylated by endogenously expressed FGFR and Src proteins. By site-directed mutagenesis, we found that Tyr18 is an FGFR1-specific ZDHHC3 phosphorylation site, while Tyr295 and Tyr297 are specifically phosphorylated by Src kinase in cell-based and cell-free assays. Abrogation of tyrosine phosphorylation increased ZDHHC3 autopalmitoylation, enhanced interaction with NCAM, and upregulated NCAM palmitoylation. Expression of ZDHHC3 with tyrosine mutated in cultured hippocampal neurons promoted neurite outgrowth. Our findings for the first time highlight that FGFR- and Src-mediated tyrosine phosphorylation of ZDHHC3 modulates ZDHHC3 enzymatic activity and plays a role in neuronal morphogenesis. PMID:27247265

  8. Cancer cell metastasis; perspectives from the focal adhesion

    Directory of Open Access Journals (Sweden)

    Lefteris C Zacharia

    2015-10-01

    Full Text Available In almost all cancers, most patients die from metastatic disease and not from the actual primary tumor. That is why addressing the problem of metastasis is of utmost importance for the successful treatment and improved survival of cancer patients. Metastasis is a complex process that ultimately leads to cancer cells spreading from the tumor to distant sites of the body. During this process, cancer cells tend to lose contact with the extracellular matrix (ECM and neighboring cells within the primary tumor, and are thus able to invade surrounding tissues. Hence, ECM, and the ECM-associated adhesion proteins play a critical role in the metastatic process. This review will focus on recent literature regarding interesting and novel molecules at the cell-ECM adhesion sites, namely migfilin, mitogen-inducible gene-2 (Mig-2 and Ras suppressor-1 (RSU-1, that are also critically involved in cancer cell metastasis, emphasizing on data from experiments performed in vitro in breast cancer and hepatocellular carcinoma cell lines as well as human breast cancer tissue samples.

  9. Hakai reduces cell-substratum adhesion and increases epithelial cell invasion

    International Nuclear Information System (INIS)

    Rodríguez-Rigueiro, Teresa; Valladares-Ayerbes, Manuel; Haz-Conde, Mar; Aparicio, Luis A; Figueroa, Angélica

    2011-01-01

    The dynamic regulation of cell-cell adhesions is crucial for developmental processes, including tissue formation, differentiation and motility. Adherens junctions are important components of the junctional complex between cells and are necessary for maintaining cell homeostasis and normal tissue architecture. E-cadherin is the prototype and best-characterized protein member of adherens junctions in mammalian epithelial cells. Regarded as a tumour suppressor, E-cadherin loss is associated with poor prognosis in carcinoma. The E3 ubiquitin-ligase Hakai was the first reported posttranslational regulator of the E-cadherin complex. Hakai specifically targetted E-cadherin for internalization and degradation and thereby lowered epithelial cell-cell contact. Hakai was also implicated in controlling proliferation, and promoted cancer-related gene expression by increasing the binding of RNA-binding protein PSF to RNAs encoding oncogenic proteins. We sought to investigate the possible implication of Hakai in cell-substratum adhesions and invasion in epithelial cells. Parental MDCK cells and MDCK cells stably overexpressing Hakai were used to analyse cell-substratum adhesion and invasion capabilities. Western blot and immunofluoresecence analyses were performed to assess the roles of Paxillin, FAK and Vinculin in cell-substratum adhesion. The role of the proteasome in controlling cell-substratum adhesion was studied using two proteasome inhibitors, lactacystin and MG132. To study the molecular mechanisms controlling Paxillin expression, MDCK cells expressing E-cadherin shRNA in a tetracycline-inducible manner was employed. Here, we present evidence that implicate Hakai in reducing cell-substratum adhesion and increasing epithelial cell invasion, two hallmark features of cancer progression and metastasis. Paxillin, an important protein component of the cell-matrix adhesion, was completely absent from focal adhesions and focal contacts in Hakai-overexpressing MDCK cells. The

  10. Low Doses of Curcuma longa Modulates Cell Migration and Cell-Cell Adhesion.

    Science.gov (United States)

    de Campos, Paloma Santos; Matte, Bibiana Franzen; Diel, Leonardo Francisco; Jesus, Luciano Henrique; Bernardi, Lisiane; Alves, Alessandro Menna; Rados, Pantelis Varvaki; Lamers, Marcelo Lazzaron

    2017-09-01

    Cell invasion and metastasis are involved in clinical failures in cancer treatment, and both events require the acquisition of a migratory behavior by tumor cells. Curcumin is a promising natural product with anti-proliferative activity, but its effects on cell migration are still unclear. We evaluated the effects of curcumin on the proliferation, apoptosis, migration, and cell-cell adhesion of keratinocyte, oral squamous cell carcinoma (OSCC), and fibroblast cell lines, as well as in a xenograft model of OSCC. Curcumin (2 μM) decreased cell proliferation in cell lines with mesenchymal characteristics, while cell death was detected only at 50 μM. We observed that highly migratory cells showed a decrease on migration speed and directionality when treated with 2 or 5 μM of curcumin (50% and 40%, respectively, p curcumin dose dependently decreased cell-cell adhesion, especially on tumor-derived spheroids. Also, in a xenograft model with patient-derived OSCC cells, the administration of curcumin decreased tumor growth and aggressiveness when compared with untreated tumors, indicating the potential antitumor effect in oral cancer. These results suggest that lower doses of curcumin can influence several steps involved in tumorigenesis, including migration properties, suggesting a possible use in cancer therapy. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  11. Cell Adhesion Molecules of the Immunoglobulin Superfamily in the Nervous System

    DEFF Research Database (Denmark)

    Walmod, Peter Schledermann; Pedersen, Martin Volmer; Berezin, Vladimir

    2007-01-01

    Cell adhesion molecules (CAMs) are proteins mediating cell-cell or cell-extracellular matrix (ECM) interactions. CAMs are traditionally divided into four groups, the cadherins, the selectins, the integrins and CAMs belonging to the immunoglobulin superfamily (IgSF). The present chapter describes...... CAMs belonging to IgSF, that exclusively or in part, are expressed in the nervous system. The chapter includes descriptions of myelin protein zero (P0), integrin-associated protein (CD47), neuroplastin, activated leukocyte-cell adhesion molecule (ALCAM), melanoma cell adhesion molecule (MCAM......), myelinassociated glycoprotein (MAG), the neural cell adhesion molecules 1 and 2 (NCAM, NCAM2), Down Syndrome cell adhesion molecule (DSCAM) and Down Syndrome cell adhesion molecule-like-1 (DSCAML1), sidekick 1 and 2 (SDK1, SDK2), signal-regulatory proteins (SIRPs), nectins, nectin-like proteins (necls...

  12. Light-triggered in vivo activation of adhesive peptides regulates cell adhesion, inflammation and vascularization of biomaterials

    Science.gov (United States)

    Lee, Ted T.; García, José R.; Paez, Julieta I.; Singh, Ankur; Phelps, Edward A.; Weis, Simone; Shafiq, Zahid; Shekaran, Asha; Del Campo, Aránzazu; García, Andrés J.

    2015-03-01

    Materials engineered to elicit targeted cellular responses in regenerative medicine must display bioligands with precise spatial and temporal control. Although materials with temporally regulated presentation of bioadhesive ligands using external triggers, such as light and electric fields, have recently been realized for cells in culture, the impact of in vivo temporal ligand presentation on cell-material responses is unknown. Here, we present a general strategy to temporally and spatially control the in vivo presentation of bioligands using cell-adhesive peptides with a protecting group that can be easily removed via transdermal light exposure to render the peptide fully active. We demonstrate that non-invasive, transdermal time-regulated activation of cell-adhesive RGD peptide on implanted biomaterials regulates in vivo cell adhesion, inflammation, fibrous encapsulation, and vascularization of the material. This work shows that triggered in vivo presentation of bioligands can be harnessed to direct tissue reparative responses associated with implanted biomaterials.

  13. Adhesion defective BHK cell mutant has cell surface heparan sulfate proteoglycan of altered properties

    DEFF Research Database (Denmark)

    Couchman, J R; Austria, R; Woods, A

    1988-01-01

    In the light of accumulating data that implicate cell surface heparan sulfate proteoglycans (HSPGs) with a role in cell interactions with extracellular matrix molecules such as fibronectin, we have compared the properties of these molecules in wild-type BHK cells and an adhesion-defective ricin......-resistant mutant (RicR14). Our results showed that the mutant, unlike BHK cells, cannot form focal adhesions when adherent to planar substrates in the presence of serum. Furthermore, while both cell lines possess similar amounts of cell surface HSPG with hydrophobic properties, that of RicR14 cells had decreased...... sulfation, reduced affinity for fibronectin and decreased half-life on the cell surface when compared to the normal counterpart. Our conclusions based on this data are that these altered properties may, in part, account for the adhesion defect in the ricin-resistant mutant. Whether this results from...

  14. CADM1 controls actin cytoskeleton assembly and regulates extracellular matrix adhesion in human mast cells.

    Directory of Open Access Journals (Sweden)

    Elena P Moiseeva

    Full Text Available CADM1 is a major receptor for the adhesion of mast cells (MCs to fibroblasts, human airway smooth muscle cells (HASMCs and neurons. It also regulates E-cadherin and alpha6beta4 integrin in other cell types. Here we investigated a role for CADM1 in MC adhesion to both cells and extracellular matrix (ECM. Downregulation of CADM1 in the human MC line HMC-1 resulted not only in reduced adhesion to HASMCs, but also reduced adhesion to their ECM. Time-course studies in the presence of EDTA to inhibit integrins demonstrated that CADM1 provided fast initial adhesion to HASMCs and assisted with slower adhesion to ECM. CADM1 downregulation, but not antibody-dependent CADM1 inhibition, reduced MC adhesion to ECM, suggesting indirect regulation of ECM adhesion. To investigate potential mechanisms, phosphotyrosine signalling and polymerisation of actin filaments, essential for integrin-mediated adhesion, were examined. Modulation of CADM1 expression positively correlated with surface KIT levels and polymerisation of cortical F-actin in HMC-1 cells. It also influenced phosphotyrosine signalling and KIT tyrosine autophosphorylation. CADM1 accounted for 46% of surface KIT levels and 31% of F-actin in HMC-1 cells. CADM1 downregulation resulted in elongation of cortical actin filaments in both HMC-1 cells and human lung MCs and increased cell rigidity of HMC-1 cells. Collectively these data suggest that CADM1 is a key adhesion receptor, which regulates MC net adhesion, both directly through CADM1-dependent adhesion, and indirectly through the regulation of other adhesion receptors. The latter is likely to occur via docking of KIT and polymerisation of cortical F-actin. Here we propose a stepwise model of adhesion with CADM1 as a driving force for net MC adhesion.

  15. Self-adhesive microculture system for extended live cell imaging.

    Science.gov (United States)

    Skommer, J; McGuinness, D; Wlodkowic, D

    2011-06-01

    Gas permeable and biocompatible soft polymers are convenient for biological applications. Using the soft polymer poly(dimethylsiloxane) (PDMS), we established a straightforward technique for in-house production of self-adhesive and optical grade microculture devices. A gas permeable PDMS layer effectively protects against medium evaporation, changes in osmolarity, contamination and drug diffusion. These chip-based devices can be used effectively for long term mammalian cell culture and support a range of bioassays used in pharmacological profiling of anti-cancer drugs. Results obtained on a panel of hematopoietic and solid tumor cell lines during screening of investigative anti-cancer agents corresponded well to those obtained in a conventional cell culture on polystyrene plates. The cumulative correlation analysis of multiple cell lines and anti-cancer drugs showed no adverse effects on cell viability or cell growth retardation during microscale static cell culture. PDMS devices also can be custom modified for many bio-analytical purposes and are interfaced easily with both inverted and upright cell imaging platforms. Moreover, PDMS microculture devices are suitable for extended real time cell imaging. Data from the multicolor, real time analysis of apoptosis on human breast cancer MCF-7 cells provided further evidence that elimination of redundant centrifugation/washing achieved during microscale real time analysis facilitates preservation of fragile apoptotic cells and provides dynamic cellular information at high resolution. Because only small reaction volumes are required, such devices offer reduced use of consumables as well as simplified manipulations during all stages of live cell imaging.

  16. Cellular Adhesion Promotes Prostate Cancer Cells Escape from Dormancy.

    Science.gov (United States)

    Ruppender, Nazanin; Larson, Sandy; Lakely, Bryce; Kollath, Lori; Brown, Lisha; Coleman, Ilsa; Coleman, Roger; Nguyen, Holly; Nelson, Peter S; Corey, Eva; Snyder, Linda A; Vessella, Robert L; Morrissey, Colm; Lam, Hung-Ming

    2015-01-01

    Dissemination of prostate cancer (PCa) cells to the bone marrow is an early event in the disease process. In some patients, disseminated tumor cells (DTC) proliferate to form active metastases after a prolonged period of undetectable disease known as tumor dormancy. Identifying mechanisms of PCa dormancy and reactivation remain a challenge partly due to the lack of in vitro models. Here, we characterized in vitro PCa dormancy-reactivation by inducing cells from three patient-derived xenograft (PDX) lines to proliferate through tumor cell contact with each other and with bone marrow stroma. Proliferating PCa cells demonstrated tumor cell-cell contact and integrin clustering by immunofluorescence. Global gene expression analyses on proliferating cells cultured on bone marrow stroma revealed a downregulation of TGFB2 in all of the three proliferating PCa PDX lines when compared to their non-proliferating counterparts. Furthermore, constitutive activation of myosin light chain kinase (MLCK), a downstream effector of integrin-beta1 and TGF-beta2, in non-proliferating cells promoted cell proliferation. This cell proliferation was associated with an upregulation of CDK6 and a downregulation of E2F4. Taken together, our data provide the first clinically relevant in vitro model to support cellular adhesion and downregulation of TGFB2 as a potential mechanism by which PCa cells may escape from dormancy. Targeting the TGF-beta2-associated mechanism could provide novel opportunities to prevent lethal PCa metastasis.

  17. Interlayer adhesion in roll-to-roll processed flexible inverted polymer solar cells

    DEFF Research Database (Denmark)

    Dupont, Stephanie R.; Oliver, Mark; Krebs, Frederik C

    2012-01-01

    demonstrate how a thin-film adhesion technique can be applied to flexible organic solar cells to obtain quantitative adhesion values. For the P3HT:PCBM-based BHJ polymer solar cells, the interface of the BHJ with the conductive polymer layer PEDOT:PSS was found to be the weakest. The adhesion fracture energy......The interlayer adhesion of roll-to-roll processed flexible inverted P3HT:PCBM bulk heterojunction (BHJ) polymer solar cells is reported. Poor adhesion between adjacent layers may result in loss of device performance from delamination driven by the thermomechanical stresses in the device. We...... energies was observed....

  18. Cell adhesion to cathodic arc plasma deposited CrAlSiN thin films

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sun Kyu, E-mail: skim@ulsan.ac.kr [School of Materials Science and Engineering, University of Ulsan, Ulsan 680-749 (Korea, Republic of); Pham, Vuong-Hung [Department of Materials Science and Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of); Kim, Chong-Hyun [Department of Food Science, Cornell University, Ithaca, NY 14853 (United States)

    2012-07-01

    Osteoblast cell response (cell adhesion, actin cytoskeleton and focal contact adhesion as well as cell proliferation) to CrN, CrAlSiN and Ti thin films was evaluated in vitro. Cell adhesion and actin stress fibers organization depended on the film composition significantly. Immunofluorescent staining of vinculin in osteoblast cells showed good focal contact adhesion on the CrAlSiN and Ti thin films but not on the CrN thin films. Cell proliferation was significantly greater on the CrAlSiN thin films as well as on Ti thin films than on the CrN thin films.

  19. Study of the time effect on the strength of cell-cell adhesion force by a novel nano-picker

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Yajing, E-mail: shen@robo.mein.naogya-u.ac.jp [Dept. of Micro-Nano Systems Engineering, Nagoya University, Nagoya 464-8603 (Japan); Nakajima, Masahiro [Center for Micro-Nano Mechatronics, Nagoya University, Nagoya 464-8603 (Japan); Kojima, Seiji; Homma, Michio [Division of Biological Science, Nagoya University, Nagoya 464-8603 (Japan); Fukuda, Toshio [Dept. of Micro-Nano Systems Engineering, Nagoya University, Nagoya 464-8603 (Japan); Center for Micro-Nano Mechatronics, Nagoya University, Nagoya 464-8603 (Japan)

    2011-06-03

    Highlights: {yields} A nano-picker is developed for single cell adhesion force measurement. {yields} The adhesion of picker-cell has no influence to the cell-cell measurement result. {yields} Cell-cell adhesion force has a rise at the first few minutes and then becomes constant. -- Abstract: Cell's adhesion is important to cell's interaction and activates. In this paper, a novel method for cell-cell adhesion force measurement was proposed by using a nano-picker. The effect of the contact time on the cell-cell adhesion force was studied. The nano-picker was fabricated from an atomic force microscopy (AFM) cantilever by nano fabrication technique. The cell-cell adhesion force was measured based on the deflection of the nano-picker beam. The result suggests that the adhesion force between cells increased with the increasing of contact time at the first few minutes. After that, the force became constant. This measurement methodology was based on the nanorobotic manipulation system inside an environmental scanning electron microscope. It can realize both the observation and manipulation of a single cell at nanoscale. The quantitative and precise cell-cell adhesion force result can be obtained by this method. It would help us to understand the single cell interaction with time and would benefit the research in medical and biological fields potentially.

  20. The cell adhesion molecule Fasciclin2 regulates brush border length and organization in Drosophila renal tubules

    DEFF Research Database (Denmark)

    Halberg, Kenneth Agerlin; Rainey, Stephanie M.; Veland, Iben Rønn

    2016-01-01

    Multicellular organisms rely on cell adhesion molecules to coordinate cell-cell interactions, and to provide navigational cues during tissue formation. In Drosophila, Fasciclin 2 (Fas2) has been intensively studied due to its role in nervous system development and maintenance; yet, Fas2 is most...... role for this well-known cell adhesion molecule, and propose that Fas2-mediated intermicrovillar homophilic adhesion complexes help stabilize the brush border....

  1. Adhesion of yeast cells on surface of polymers produced by radiation polymerization

    International Nuclear Information System (INIS)

    Lu, Zhaoxin; Takehisa, Masaaki; Xie Zongchuan.

    1995-01-01

    The adhesion of yeast (Saccharomyces formesences) cells on polymers was studied thermodynamically. The polymers were laminally prepared by means of radiation polymerization. By measuring contact angles, we calculated dispersion component and polar component of surface free energy of the polymers and the cells, and interfacial free energy between the polymer and the cells. Then interfacial free energy change of the cell adhesion to surface of the polymer was evaluated. The adhesion behavior of yeast cells on the polymers was observed by optical microscope. From above results, we conclude that the initial adhesion of the cells is related to the surface free energy of the polymer, but the irreversible adhesion may be close to the polar component in surface free energy. The high polar component is favourable the irreversible adhesion of yeast cells. (author)

  2. Laminin-dependent and laminin-independent adhesion of human melanoma cells to sulfatides

    DEFF Research Database (Denmark)

    Roberts, D D; Wewer, U M; Liotta, L A

    1988-01-01

    Sulfatides (galactosylceramide-I3-sulfate) but not neutral glycolipids or gangliosides adsorbed on plastic promote adhesion of the human melanoma cell line G361. Direct adhesion of G361 cells requires densities of sulfatide greater than 1 pmol/mm2. In the presence of laminin, however, specific...... adhesion of G361 cells to sulfatide or seminolipid (galactosylalkylacyl-glycerol-I3-sulfate) but not to other lipids is strongly stimulated and requires only 25 fmol/mm2 of adsorbed lipid. The effects of laminin and sulfatide on adhesion are synergistic, suggesting that laminin is mediating adhesion...... by cross-linking receptors on the melanoma cell surface to sulfatide adsorbed on the plastic. Although thrombospondin binds to sulfatides and G361 cells, it does not enhance, but rather inhibits direct and laminin-dependent G361 cell adhesion to sulfatide. In contrast, C32 melanoma cells also adhere...

  3. Angiogenesis mediated by soluble forms of E-selectin and vascular cell adhesion molecule-1

    Science.gov (United States)

    Koch, Alisa E.; Halloran, Margaret M.; Haskell, Catherine J.; Shah, Manisha R.; Polverini, Peter J.

    1995-08-01

    ENDOTHELIAL adhesion molecules facilitate the entry of leukocytes into inflamed tissues. This in turn promotes neovascularization, a process central to the progression of rheumatoid arthritis, tumour growth and wound repair1. Here we test the hypothesis that soluble endothelial adhesion molecules promote angiogenesis2á¤-4. Human recombinant soluble E-selectin and soluble vascular cell adhesion molecule-1 induced chemotaxis of human endothelial cells in vitro and were angiogenic in rat cornea. Soluble E-selectin acted on endothelial cells in part through a sialyl Lewis-X-dependent mechanism, while soluble vascular cell adhesion molecule-1 acted on endothelial cells in part through a very late antigen (VLA)-4 dependent mechanism. The chemotactic activity of rheumatoid synovial fluid for endothelial cells, and also its angiogenic activity, were blocked by antibodies to either soluble E-selectin or soluble vascular cell adhesion molecule-1. These results suggest a novel function for soluble endothelial adhesion molecules as mediators of angiogenesis.

  4. Llgl1 Connects Cell Polarity with Cell-Cell Adhesion in Embryonic Neural Stem Cells.

    Science.gov (United States)

    Jossin, Yves; Lee, Minhui; Klezovitch, Olga; Kon, Elif; Cossard, Alexia; Lien, Wen-Hui; Fernandez, Tania E; Cooper, Jonathan A; Vasioukhin, Valera

    2017-06-05

    Malformations of the cerebral cortex (MCCs) are devastating developmental disorders. We report here that mice with embryonic neural stem-cell-specific deletion of Llgl1 (Nestin-Cre/Llgl1 fl/fl ), a mammalian ortholog of the Drosophila cell polarity gene lgl, exhibit MCCs resembling severe periventricular heterotopia (PH). Immunohistochemical analyses and live cortical imaging of PH formation revealed that disruption of apical junctional complexes (AJCs) was responsible for PH in Nestin-Cre/Llgl1 fl/fl brains. While it is well known that cell polarity proteins govern the formation of AJCs, the exact mechanisms remain unclear. We show that LLGL1 directly binds to and promotes internalization of N-cadherin, and N-cadherin/LLGL1 interaction is inhibited by atypical protein kinase C-mediated phosphorylation of LLGL1, restricting the accumulation of AJCs to the basolateral-apical boundary. Disruption of the N-cadherin-LLGL1 interaction during cortical development in vivo is sufficient for PH. These findings reveal a mechanism responsible for the physical and functional connection between cell polarity and cell-cell adhesion machineries in mammalian cells. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Cell-extracellular matrix and cell-cell adhesion are linked by syndecan-4

    DEFF Research Database (Denmark)

    Pakideeri Karat, Sandeep Gopal; Multhaupt, Hinke A B; Pocock, Roger

    2017-01-01

    Cell-extracellular matrix (ECM) and cell-cell junctions that employ microfilaments are sites of tension. They are important for tissue repair, morphogenetic movements and can be emblematic of matrix contraction in fibrotic disease and the stroma of solid tumors. One cell surface receptor, syndecan...... calcium. While it is known that cell-ECM and cell-cell junctions may be linked, possible roles for syndecans in this process are not understood. Here we show that wild type primary fibroblasts and those lacking syndecan-4 utilize different cadherins in their adherens junctions and that tension is a major...... factor in this differential response. This corresponds to the reduced ability of fibroblasts lacking syndecan-4 to exert tension on the ECM and we now show that this may extend to reduced tension in cell-cell adhesion....

  6. A new technical approach to quantify cell-cell adhesion forces by AFM

    International Nuclear Information System (INIS)

    Puech, Pierre-Henri; Poole, Kate; Knebel, Detlef; Muller, Daniel J.

    2006-01-01

    Cell-cell adhesion is a complex process that is involved in the tethering of cells, cell-cell communication, tissue formation, cell migration and the development and metastasis of tumors. Given the heterogeneous and complex nature of cell surfaces it has previously proved difficult to characterize individual cell-cell adhesion events. Force spectroscopy, using an atomic force microscope, is capable of resolving such individual cell-cell binding events, but has previously been limited in its application due to insufficient effective pulling distances. Extended pulling range is critical in studying cell-cell interactions due to the potential for large cell deformations. Here we describe an approach to such experiments, where the sample stage can be moved 100 μm in the z-direction, by closed loop, linearized piezo elements. Such an approach enables an increase in pulling distance sufficient for the observation of long-distance cell-unbinding events without reducing the imaging capabilities of the atomic force microscope. The atomic force microscope head and the piezo-driven sample stage are installed on an inverted optical microscope fitted with a piezo-driven objective, to allow the monitoring of cell morphology by conventional light microscopy, concomitant with force spectroscopy measurements. We have used the example of the WM115 melanoma cell line binding to human umbilical vein endothelial cells to demonstrate the capabilities of this system and the necessity for such an extended pulling range when quantifying cell-cell adhesion events

  7. Embryonic cell-cell adhesion: a key player in collective neural crest migration.

    Science.gov (United States)

    Barriga, Elias H; Mayor, Roberto

    2015-01-01

    Cell migration is essential for morphogenesis, adult tissue remodeling, wound healing, and cancer cell migration. Cells can migrate as individuals or groups. When cells migrate in groups, cell-cell interactions are crucial in order to promote the coordinated behavior, essential for collective migration. Interestingly, recent evidence has shown that cell-cell interactions are also important for establishing and maintaining the directionality of these migratory events. We focus on neural crest cells, as they possess extraordinary migratory capabilities that allow them to migrate and colonize tissues all over the embryo. Neural crest cells undergo an epithelial-to-mesenchymal transition at the same time than perform directional collective migration. Cell-cell adhesion has been shown to be an important source of planar cell polarity and cell coordination during collective movement. We also review molecular mechanisms underlying cadherin turnover, showing how the modulation and dynamics of cell-cell adhesions are crucial in order to maintain tissue integrity and collective migration in vivo. We conclude that cell-cell adhesion during embryo development cannot be considered as simple passive resistance to force, but rather participates in signaling events that determine important cell behaviors required for cell migration. © 2015 Elsevier Inc. All rights reserved.

  8. Adhesion behavior of endothelial progenitor cells to endothelial cells in simple shear flow

    Science.gov (United States)

    Gong, Xiao-Bo; Li, Yu-Qing; Gao, Quan-Chao; Cheng, Bin-Bin; Shen, Bao-Rong; Yan, Zhi-Qiang; Jiang, Zong-Lai

    2011-12-01

    The adhesion of endothelial progenitor cells (EPCs) on endothelial cells (ECs) is one of the critical physiological processes for the regenesis of vascular vessels and the prevention of serious cardiovascular diseases. Here, the rolling and adhesion behavior of EPCs on ECs was studied numerically. A two-dimensional numerical model was developed based on the immersed boundary method for simulating the rolling and adhesion of cells in a channel flow. The binding force arising from the catch bond of a receptor and ligand pair was modeled with stochastic Monte Carlo method and Hookean spring model. The effect of tumor necrosis factor alpha (TNF- α) on the expression of the number of adhesion molecules in ECs was analyzed experimentally. A flow chamber system with CCD camera was set up to observe the top view of the rolling of EPCs on the substrate cultivated with ECs. Numerical results prove that the adhesion of EPC on ECs is closely related to membrane stiffness of the cell and shear rate of the flow. It also suggests that the adhesion force between EPC and EC by P-selectin glycoprotein ligand-1 only is not strong enough to bond the cell onto vessel walls unless contributions of other catch bond are considered. Experimental results demonstrate that TNF- α enhanced the expressions of VCAM, ICAM, P-selectin and E-selectin in ECs, which supports the numerical results that the rolling velocity of EPC on TNF- α treated EC substrate decreases obviously compared with its velocity on the untreated one. It is found that because the adhesion is affected by both the rolling velocity and the deformability of the cell, an optimal stiffness of EPC may exist at a given shear rate of flow for achieving maximum adhesion rates.

  9. Mechanism of mast cell adhesion to human tenocytes in vitro.

    Science.gov (United States)

    Behzad, Hayedeh; Tsai, Shu-Huei; Nassab, Paulina; Mousavizadeh, Rouhollah; McCormack, Robert G; Scott, Alex

    2015-01-01

    Mast cells and fibroblasts are two key players involved in many fibrotic and degenerative disorders. In the present study we examined the nature of binding interactions between human mast cells and tendon fibroblasts (tenocytes). In the mast cell-fibroblast co-culture model, mast cells were shown to spontaneously bind to tenocytes, in a process that was partially mediated by α5β1 integrin receptors. The same receptors on mast cells significantly mediated binding of these cells to tissue culture plates in the presence of tenocyte-conditioned media; the tenocyte-derived fibronectin in the media was shown to also play a major role in these binding activities. Upon binding to tenocytes or tissue culture plates, mast cells acquired an elongated phenotype, which was dependent on α5β1 integrin and tenocyte fibronectin. Additionally, tenocyte-derived fibronectin significantly enhanced mRNA expression of the adhesion molecule, THY1, by mast cells. Our data suggests that α5β1 integrin mediates binding of mast cells to human tenocyte and to tenocyte-derived ECM proteins, in particular fibronectin. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  10. CD13 is a novel mediator of monocytic/endothelial cell adhesion

    DEFF Research Database (Denmark)

    Mina-Osorio, Paola; Winnicka, Beata; O'Conor, Catherine

    2008-01-01

    During inflammation, cell surface adhesion molecules guide the adhesion and migration of circulating leukocytes across the endothelial cells lining the blood vessels to access the site of injury. The transmembrane molecule CD13 is expressed on monocytes and endothelial cells and has been shown...... to mediate homotypic cell adhesion, which may imply a role for CD13 in inflammatory monocyte trafficking. Here, we show that ligation and clustering of CD13 by mAb or viral ligands potently induce myeloid cell/endothelial adhesion in a signal transduction-dependent manner involving monocytic cytoskeletal...... rearrangement and filopodia formation. Treatment with soluble recombinant (r)CD13 blocks this CD13-dependent adhesion, and CD13 molecules from monocytic and endothelial cells are present in the same immunocomplex, suggesting a direct participation of CD13 in the adhesive interaction. This concept...

  11. Vascular cell adhesion molecule-1 is a key adhesion molecule in melanoma cell adhesion to the leptomeninges

    NARCIS (Netherlands)

    Brandsma, Dieta; Reijneveld, Jaap C.; Taphoorn, Martin J. B.; de Boer, Hetty C.; Gebbink, Martijn F. B. G.; Ulfman, Laurien H.; Zwaginga, Jaap-Jan; Voest, Emile E.

    2002-01-01

    Leptomeningeal metastases occur in up to 8% of patients with systemic malignancies and have a poor prognosis. A better understanding of the pathophysiologic processes underlying leptomeningeal metastases is needed for more effective treatment strategies. We hypothesized that tumor cells will have to

  12. Integrin and glycocalyx mediated contributions to cell adhesion identified by single cell force spectroscopy

    International Nuclear Information System (INIS)

    Boettiger, D; Wehrle-Haller, B

    2010-01-01

    The measurement of cell adhesion using single cell force spectroscopy methods was compared with earlier methods for measuring cell adhesion. This comparison provided a means and rationale for separating components of the measurement retract curve that were due to interactions between the substrate and the glycocalyx, and interactions that were due to cell surface integrins binding to a substrate-bound ligand. The glycocalyx adhesion was characterized by multiple jumps with dispersed jump sizes that extended from 5 to 30 μm from the origin. The integrin mediated adhesion was represented by the F max (maximum detachment force), was generally within the first 5 μm and commonly detached with a single rupture cascade. The integrin peak (F max ) increases with time and the rate of increase shows large cell to cell variability with a peak ∼ 50 nN s -1 and an average rate of increase of 75 pN s -1 . This is a measure of the rate of increase in the number of adhesive integrin-ligand bonds/cell as a function of contact time.

  13. Basal cell adhesion molecule/lutheran protein. The receptor critical for sickle cell adhesion to laminin.

    Science.gov (United States)

    Udani, M; Zen, Q; Cottman, M; Leonard, N; Jefferson, S; Daymont, C; Truskey, G; Telen, M J

    1998-01-01

    Sickle red cells bind significant amounts of soluble laminin, whereas normal red cells do not. Solid phase assays demonstrate that B-CAM/LU binds laminin on intact sickle red cells and that red cell B-CAM/LU binds immobilized laminin, whereas another putative laminin binding protein, CD44, does not. Ligand blots also identify B-CAM/LU as the only erythrocyte membrane protein(s) that binds laminin. Finally, transfection of murine erythroleukemia cells with human B-CAM cDNA induces binding of both soluble and immobilized laminin. Thus, B-CAM/LU appears to be the major laminin-binding protein of sickle red cells. Previously reported overexpression of B-CAM/LU by epithelial cancer cells suggests that this protein may also serve as a laminin receptor in malignant tumors. PMID:9616226

  14. Regulation of endothelial cell adhesion molecule expression by mast cells, macrophages, and neutrophils.

    Directory of Open Access Journals (Sweden)

    Jie Zhang

    2011-01-01

    Full Text Available Leukocyte adhesion to the vascular endothelium and subsequent transendothelial migration play essential roles in the pathogenesis of cardiovascular diseases such as atherosclerosis. The leukocyte adhesion is mediated by localized activation of the endothelium through the action of inflammatory cytokines. The exact proinflammatory factors, however, that activate the endothelium and their cellular sources remain incompletely defined.Using bone marrow-derived mast cells from wild-type, Tnf(-/-, Ifng(-/-, Il6(-/- mice, we demonstrated that all three of these pro-inflammatory cytokines from mast cells induced the expression of vascular cell adhesion molecule-1 (VCAM-1, intercellular adhesion molecule-1 (ICAM-1, P-selectin, and E-selectin in murine heart endothelial cells (MHEC at both mRNA and protein levels. Compared with TNF-α and IL6, IFN-γ appeared weaker in the induction of the mRNA levels, but at protein levels, both IL6 and IFN-γ were weaker inducers than TNF-α. Under physiological shear flow conditions, mast cell-derived TNF-α and IL6 were more potent than IFN-γ in activating MHEC and in promoting neutrophil adhesion. Similar observations were made when neutrophils or macrophages were used. Neutrophils and macrophages produced the same sets of pro-inflammatory cytokines as did mast cells to induce MHEC adhesion molecule expression, with the exception that macrophage-derived IFN-γ showed negligible effect in inducing VCAM-1 expression in MHEC.Mast cells, neutrophils, and macrophages release pro-inflammatory cytokines such as TNF-α, IFN-γ, and IL6 that induce expression of adhesion molecules in endothelium and recruit of leukocytes, which is essential to the pathogenesis of vascular inflammatory diseases.

  15. Cell-contact-dependent activation of CD4+ T cells by adhesion molecules on synovial fibroblasts.

    Science.gov (United States)

    Mori, Masato; Hashimoto, Motomu; Matsuo, Takashi; Fujii, Takao; Furu, Moritoshi; Ito, Hiromu; Yoshitomi, Hiroyuki; Hirose, Jun; Ito, Yoshinaga; Akizuki, Shuji; Nakashima, Ran; Imura, Yoshitaka; Yukawa, Naoichiro; Yoshifuji, Hajime; Ohmura, Koichiro; Mimori, Tsuneyo

    2017-05-01

    To determine how cell-cell contact with synovial fibroblasts (SF) influence on the proliferation and cytokine production of CD4 +  T cells. Naïve CD4 +  T cells were cultured with SF from rheumatoid arthritis patients, stimulated by anti-CD3/28 antibody, and CD4 +  T cell proliferation and IFN-γ/IL-17 production were analyzed. To study the role of adhesion molecules, cell contact was blocked by transwell plate or anti-intracellular adhesion molecule-1 (ICAM-1)/vascular cell adhesion molecule-1(VCAM-1) antibody. To study the direct role of adhesion molecules for CD4 +  T cells, CD161 +  or CD161 - naïve CD4 +  T cells were stimulated on plastic plates coated by recombinant ICAM-1 or VCAM-1, and the source of IFN-γ/IL-17 were analyzed. SF enhanced naïve CD4 +  T cell proliferation and IFN-γ/IL-17 production in cell-contact and in part ICAM-1-/VCAM-1-dependent manner. Plate-coated ICAM-1 and VCAM-1 enhanced naïve CD4 +  T cell proliferation and IFN-γ production, while VCAM-1 efficiently promoting IL-17 production. CD161 +  naïve T cells upregulating LFA-1 and VLA-4 were the major source of IFN-γ/IL-17 upon interaction with ICAM-1/VCAM-1. CD4 +  T cells rapidly expand and secrete IFN-γ/IL-17 upon cell-contact with SF via adhesion molecules. Interfering with ICAM-1-/VCAM-1 may be beneficial for inhibiting RA synovitis.

  16. MHC class II ligation induces CD58 (LFA-3)-mediated adhesion in human T cells

    DEFF Research Database (Denmark)

    Nielsen, M; Gerwien, J; Geisler, C

    1998-01-01

    ligation induces homotypic adhesion in both beta2-integrin-positive and negative, CD4-positive T cell lines. Anti-CD18 monoclonal antibody (mAb) weakly inhibited the adhesion response in beta2-integrin-positive T cells and had no effect on beta2-integrin-negative T cells. In contrast, an anti-CD58 (LFA-3...

  17. A simplified model for dynamics of cell rolling and cell-surface adhesion

    International Nuclear Information System (INIS)

    Cimrák, Ivan

    2015-01-01

    We propose a three dimensional model for the adhesion and rolling of biological cells on surfaces. We study cells moving in shear flow above a wall to which they can adhere via specific receptor-ligand bonds based on receptors from selectin as well as integrin family. The computational fluid dynamics are governed by the lattice-Boltzmann method. The movement and the deformation of the cells is described by the immersed boundary method. Both methods are fully coupled by implementing a two-way fluid-structure interaction. The adhesion mechanism is modelled by adhesive bonds including stochastic rules for their creation and rupture. We explore a simplified model with dissociation rate independent of the length of the bonds. We demonstrate that this model is able to resemble the mesoscopic properties, such as velocity of rolling cells

  18. Exendin-4 induces cell adhesion and differentiation and counteracts the invasive potential of human neuroblastoma cells.

    Science.gov (United States)

    Luciani, Paola; Deledda, Cristiana; Benvenuti, Susanna; Squecco, Roberta; Cellai, Ilaria; Fibbi, Benedetta; Marone, Ilaria Maddalena; Giuliani, Corinna; Modi, Giulia; Francini, Fabio; Vannelli, Gabriella Barbara; Peri, Alessandro

    2013-01-01

    Exendin-4 is a molecule currently used, in its synthetic form exenatide, for the treatment of type 2 diabetes mellitus. Exendin-4 binds and activates the Glucagon-Like Peptide-1 Receptor (GLP-1R), thus inducing insulin release. More recently, additional biological properties have been associated to molecules that belong to the GLP-1 family. For instance, Peptide YY and Vasoactive Intestinal Peptide have been found to affect cell adhesion and migration and our previous data have shown a considerable actin cytoskeleton rearrangement after exendin-4 treatment. However, no data are currently available on the effects of exendin-4 on tumor cell motility. The aim of this study was to investigate the effects of this molecule on cell adhesion, differentiation and migration in two neuroblastoma cell lines, SH-SY5Y and SK-N-AS. We first demonstrated, by Extra Cellular Matrix cell adhesion arrays, that exendin-4 increased cell adhesion, in particular on a vitronectin substrate. Subsequently, we found that this molecule induced a more differentiated phenotype, as assessed by i) the evaluation of neurite-like protrusions in 3D cell cultures, ii) the analysis of the expression of neuronal markers and iii) electrophysiological studies. Furthermore, we demonstrated that exendin-4 reduced cell migration and counteracted anchorage-independent growth in neuroblastoma cells. Overall, these data indicate for the first time that exendin-4 may have anti-tumoral properties.

  19. CD147-targeting siRNA inhibits cell-matrix adhesion of human malignant melanoma cells by phosphorylating focal adhesion kinase.

    Science.gov (United States)

    Nishibaba, Rie; Higashi, Yuko; Su, Juan; Furukawa, Tatsuhiko; Kawai, Kazuhiro; Kanekura, Takuro

    2012-01-01

    CD147/basigin, highly expressed on the surface of malignant tumor cells including malignant melanoma (MM) cells, plays a critical role in the invasiveness and metastasis of MM. Metastasis is an orchestrated process comprised of multiple steps including adhesion and invasion. Integrin, a major adhesion molecule, co-localizes with CD147/basigin on the cell surface. Using the human MM cell line A375 that highly expresses CD147/basigin, we investigated whether CD147/basigin is involved in adhesion in association with integrin. CD147/basigin was knocked-down using siRNA targeting CD147 to elucidate the role of CD147/basigin. Cell adhesion was evaluated by adhesion assay on matrix-coated plates. The localization of integrin was inspected under a confocal microscope and the expression and phosphorylation of focal adhesion kinase (FAK), a downstream kinase of integrin, were examined by western blot analysis. Silencing of CD147/basigin in A375 cells by siRNA induced the phosphorylation of FAK at Y397. Integrin identified on the surface of parental cells was distributed in a speckled fashion in the cytoplasm of CD147 knockdown cells, resulting in morphological changes from a round to a polygonal shape with pseudopodial protrusions. Silencing of CD147/basigin in A375 cells clearly weakened their adhesiveness to collagen I and IV. Our results suggest that CD147/basigin regulates the adhesion of MM cells to extracellular matrices and of integrin β1 signaling via the phosphorylation of FAK. © 2011 Japanese Dermatological Association.

  20. A mucus adhesion promoting protein, MapA, mediates the adhesion of Lactobacillus reuteri to Caco-2 human intestinal epithelial cells.

    Science.gov (United States)

    Miyoshi, Yukihiro; Okada, Sanae; Uchimura, Tai; Satoh, Eiichi

    2006-07-01

    Lactobacillus reuteri is one of the dominant lactobacilli found in the gastrointestinal tract of various animals. A surface protein of L. reuteri 104R, mucus adhesion promoting protein (MapA), is considered to be an adhesion factor of this strain. We investigated the relation between MapA and adhesion of L. reuteri to human intestinal (Caco-2) cells. Quantitative analysis of the adhesion of L. reuteri strains to Caco-2 cells showed that various L. reuteri strains bind not only to mucus but also to intestinal epithelial cells. In addition, purified MapA bound to Caco-2 cells, and this binding inhibited the adhesion of L. reuteri in a concentration-dependent manner. Based on these observations, the adhesion of L. reuteri appears due to the binding of MapA to receptor-like molecules on Caco-2 cells. Further, far-western analysis indicated the existence of multiple receptor-like molecules in Caco-2 cells.

  1. Tuning cell adhesion on polymeric and nanocomposite surfaces: Role of topography versus superhydrophobicity

    Energy Technology Data Exchange (ETDEWEB)

    Zangi, Sepideh [Department of Chemical Engineering, Shahrood Branch, Islamic Azad University, P.O. Box 36155-163, Shahrood (Iran, Islamic Republic of); Hejazi, Iman [Department of Polymer Engineering & Color Technology, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Seyfi, Javad, E-mail: Jseyfi@gmail.com [Department of Chemical Engineering, Shahrood Branch, Islamic Azad University, P.O. Box 36155-163, Shahrood (Iran, Islamic Republic of); Hejazi, Ehsan [Department of Clinical Nutrition and Dietetics, Faculty of Nutrition Sciences and Food Technology, Shahid Beheshti University of Medical Sciences, Tehran (Iran, Islamic Republic of); Khonakdar, Hossein Ali [Department of Polymer Engineering, Faculty of Engineering, South Tehran Branch, Islamic Azad University, P.O. Box 19585-466, Tehran (Iran, Islamic Republic of); Davachi, Seyed Mohammad [School of Chemical Engineering, University of Tehran, P.O. Box 11155-4563, Tehran (Iran, Islamic Republic of)

    2016-06-01

    Development of surface modification procedures which allow tuning the cell adhesion on the surface of biomaterials and devices is of great importance. In this study, the effects of different topographies and wettabilities on cell adhesion behavior of polymeric surfaces are investigated. To this end, an improved phase separation method was proposed to impart various wettabilities (hydrophobic and superhydrophobic) on polypropylene surfaces. Surface morphologies and compositions were characterized by scanning electron microscopy and X-ray photoelectron spectroscopy, respectively. Cell culture was conducted to evaluate the adhesion of 4T1 mouse mammary tumor cells. It was found that processing conditions such as drying temperature is highly influential in cell adhesion behavior due to the formation of an utterly different surface topography. It was concluded that surface topography plays a more significant role in cell adhesion behavior rather than superhydrophobicity since the nano-scale topography highly inhibited the cell adhesion as compared to the micro-scale topography. Such cell repellent behavior could be very useful in many biomedical devices such as those in drug delivery and blood contacting applications as well as biosensors. - Highlights: • A novel method is presented for fabrication of superhydrophobic surfaces. • The presence of nanoparticles in non-solvent bath notably promoted phase separation. • Topography had a more notable impact on cell adhesion than superhydrophobicity. • Nano-scale topographical features highly impeded cell adhesion on polymer surfaces.

  2. Tuning cell adhesion on polymeric and nanocomposite surfaces: Role of topography versus superhydrophobicity

    International Nuclear Information System (INIS)

    Zangi, Sepideh; Hejazi, Iman; Seyfi, Javad; Hejazi, Ehsan; Khonakdar, Hossein Ali; Davachi, Seyed Mohammad

    2016-01-01

    Development of surface modification procedures which allow tuning the cell adhesion on the surface of biomaterials and devices is of great importance. In this study, the effects of different topographies and wettabilities on cell adhesion behavior of polymeric surfaces are investigated. To this end, an improved phase separation method was proposed to impart various wettabilities (hydrophobic and superhydrophobic) on polypropylene surfaces. Surface morphologies and compositions were characterized by scanning electron microscopy and X-ray photoelectron spectroscopy, respectively. Cell culture was conducted to evaluate the adhesion of 4T1 mouse mammary tumor cells. It was found that processing conditions such as drying temperature is highly influential in cell adhesion behavior due to the formation of an utterly different surface topography. It was concluded that surface topography plays a more significant role in cell adhesion behavior rather than superhydrophobicity since the nano-scale topography highly inhibited the cell adhesion as compared to the micro-scale topography. Such cell repellent behavior could be very useful in many biomedical devices such as those in drug delivery and blood contacting applications as well as biosensors. - Highlights: • A novel method is presented for fabrication of superhydrophobic surfaces. • The presence of nanoparticles in non-solvent bath notably promoted phase separation. • Topography had a more notable impact on cell adhesion than superhydrophobicity. • Nano-scale topographical features highly impeded cell adhesion on polymer surfaces.

  3. Modeling cell adhesion and proliferation: a cellular-automata based approach.

    Science.gov (United States)

    Vivas, J; Garzón-Alvarado, D; Cerrolaza, M

    Cell adhesion is a process that involves the interaction between the cell membrane and another surface, either a cell or a substrate. Unlike experimental tests, computer models can simulate processes and study the result of experiments in a shorter time and lower costs. One of the tools used to simulate biological processes is the cellular automata, which is a dynamic system that is discrete both in space and time. This work describes a computer model based on cellular automata for the adhesion process and cell proliferation to predict the behavior of a cell population in suspension and adhered to a substrate. The values of the simulated system were obtained through experimental tests on fibroblast monolayer cultures. The results allow us to estimate the cells settling time in culture as well as the adhesion and proliferation time. The change in the cells morphology as the adhesion over the contact surface progress was also observed. The formation of the initial link between cell and the substrate of the adhesion was observed after 100 min where the cell on the substrate retains its spherical morphology during the simulation. The cellular automata model developed is, however, a simplified representation of the steps in the adhesion process and the subsequent proliferation. A combined framework of experimental and computational simulation based on cellular automata was proposed to represent the fibroblast adhesion on substrates and changes in a macro-scale observed in the cell during the adhesion process. The approach showed to be simple and efficient.

  4. Transfection of glioma cells with the neural-cell adhesion molecule NCAM

    DEFF Research Database (Denmark)

    Edvardsen, K; Pedersen, P H; Bjerkvig, R

    1994-01-01

    The tumor growth and the invasive capacity of a rat glioma cell line (BT4Cn) were studied after transfection with the human transmembrane 140-kDa isoform of the neural-cell adhesion molecule, NCAM. After s.c. injection, the NCAM-transfected cells showed a slower growth rate than the parent cell...... of the injection site, with a sharply demarcated border between the tumor and brain tissue. In contrast, the parental cell line showed single-cell infiltration and more pronounced destruction of normal brain tissue. Using a 51Cr-release assay, spleen cells from rats transplanted with BT4Cn tumor cells generally...

  5. Effects of Uptake of Hydroxyapatite Nanoparticles into Hepatoma Cells on Cell Adhesion and Proliferation

    Directory of Open Access Journals (Sweden)

    Meizhen Yin

    2014-01-01

    Full Text Available Hydroxyapatite nanoparticles (nano-HAPs were prepared by homogeneous precipitation, and size distribution and morphology of these nanoparticles were determined by laser particle analysis and transmission electron microscopy, respectively. Nano-HAPs were uniformly distributed, with rod-like shapes sizes ranging from 44.6 to 86.8 nm. Attached overnight, suspended, and proliferating Bel-7402 cells were repeatedly incubated with nano-HAPs. Inverted microscopy, transmission electron microscopy, and fluorescence microscopy were used to observe the cell adhesion and growth, the culture medium containing nano-HAPs, the cell ultrastructure, and intracellular Ca2+ labeled with a fluo-3 calcium fluorescent probe. The results showed that nano-HAPs inhibited proliferation of Bel-7402 cells and, caused an obvious increase in the concentration of intracellular Ca2+, along with significant changes in the cell ultrastructure. Moreover, nano-HAPs led suspended cells and proliferating cells after trypsinized that did not attach to the bottom of the culture bottle died. Nano-HAPs continuously entered these cells. Attached, suspended, and proliferating cells endocytosed nano-HAPs, and nanoparticle-filled vesicles were in the cytoplasm. Therefore, hepatoma cellular uptake of nano-HAPs through endocytosis was very active and occurred continuously. Nano-HAPs affected proliferation and adhesion of hepatoma cells probably because uptake of nano-HAPs blocked integrin-mediated cell adhesion, which may have potential significance in inhibiting metastatic cancer cells to their target organ.

  6. Differential Cell Adhesion of Breast Cancer Stem Cells on Biomaterial Substrate with Nanotopographical Cues

    Directory of Open Access Journals (Sweden)

    Kenneth K.B. Tan

    2015-04-01

    Full Text Available Cancer stem cells are speculated to have the capability of self-renewal and re-establishment of tumor heterogeneity, possibly involved in the potential relapse of cancer. CD44+CD24−/lowESA+ cells have been reported to possess tumorigenic properties, and these biomarkers are thought to be highly expressed in breast cancer stem cells. Cell behavior can be influenced by biomolecular and topographical cues in the natural microenvironment. We hypothesized that different cell populations in breast cancer tissue exhibit different adhesion characteristics on substrates with nanotopography. Adhesion characterizations were performed using human mammary epithelial cells (HMEC, breast cancer cell line MCF7 and primary invasive ductal carcinoma (IDC cells obtained from patients’ samples, on micro- and nano-patterned poly-L-lactic acid (PLLA films. Topography demonstrated a significant effect on cell adhesion, and the effect was cell type dependent. Cells showed elongation morphology on gratings. The CD44+CD24−/lowESA+ subpopulation in MCF7 and IDC cells showed preferential adhesion on 350-nm gratings. Flow cytometry analysis showed that 350-nm gratings captured a significantly higher percentage of CD44+CD24− in MCF7. A slightly higher percentage of CD44+CD24−/lowESA+ was captured on the 350-nm gratings, although no significant difference was observed in the CD44+CD24−ESA+ in IDC cells across patterns. Taken together, the study demonstrated that the cancer stem cell subpopulation could be enriched using different nanopatterns. The enriched population could subsequently aid in the isolation and characterization of cancer stem cells.

  7. Expression of MLN64 influences cellular matrix adhesion of breast cancer cells, the role for focal adhesion kinase.

    Science.gov (United States)

    Cai, Wei; Ye, Lin; Sun, Jiabang; Mansel, Robert E; Jiang, Wen G

    2010-04-01

    The metastatic lymph node 64 (MLN64) gene was initially identified as highly expressed in the metastatic lymph node from breast cancer. It is localized in q12-q21 of the human chromosome 17 and is often co-amplified with erbB-2. However, the role played by MLN64 in breast cancer remains unclear. In the present study, the expression of MLN64 was examined in a breast cancer cohort using quantitative real-time PCR and immunohistochemical staining. It demonstrated that MLN64 was highly expressed in breast tumours compared to corresponding background tissues at both transcript level and protein level. The elevated level of MLN64 transcripts was correlated with the poor prognosis and overall survival of the patients. A panel of breast cancer cell sublines was subsequently developed by knockdown of MLN64 expression. Loss of MLN64 expression in MCF-7 cells resulted in a significant reduction of cell growth (absorbance for MCF-7DeltaMLN64 being 0.87+/-0.07, Padhesion assay, MDA-MB-231DeltaMLN64 cells showed a significant increase in adhesion (86+/-14), padhesion kinase (FAK) in MDA-MB-231DeltaMLN64 cells using Western blot analysis and immunofluorescent staining of FAK. Moreover, addition of FAK inhibitor to these cells diminished the effect of MLN64 on cell-matrix adhesion, suggesting that FAK contributed to the increased adhesion in MDA-MB-231DeltaMLN64 cells. In conclusion, MLN64 is overexpressed in breast cancer, and its level correlates with poor prognosis and patient survival. MLN64 contributes to the development and progression of breast cancer through the regulation of cell proliferation and adhesive capacity.

  8. Flagellin based biomimetic coatings: From cell-repellent surfaces to highly adhesive coatings.

    Science.gov (United States)

    Kovacs, Boglarka; Patko, Daniel; Szekacs, Inna; Orgovan, Norbert; Kurunczi, Sandor; Sulyok, Attila; Khanh, Nguyen Quoc; Toth, Balazs; Vonderviszt, Ferenc; Horvath, Robert

    2016-09-15

    Biomimetic coatings with cell-adhesion-regulating functionalities are intensively researched today. For example, cell-based biosensing for drug development, biomedical implants, and tissue engineering require that the surface adhesion of living cells is well controlled. Recently, we have shown that the bacterial flagellar protein, flagellin, adsorbs through its terminal segments to hydrophobic surfaces, forming an oriented monolayer and exposing its variable D3 domain to the solution. Here, we hypothesized that this nanostructured layer is highly cell-repellent since it mimics the surface of the flagellar filaments. Moreover, we proposed flagellin as a carrier molecule to display the cell-adhesive RGD (Arg-Gly-Asp) peptide sequence and induce cell adhesion on the coated surface. The D3 domain of flagellin was replaced with one or more RGD motifs linked by various oligopeptides modulating flexibility and accessibility of the inserted segment. The obtained flagellin variants were applied to create surface coatings inducing cell adhesion and spreading to different levels, while wild-type flagellin was shown to form a surface layer with strong anti-adhesive properties. As reference surfaces synthetic polymers were applied which have anti-adhesive (PLL-g-PEG poly(l-lysine)-graft-poly(ethylene glycol)) or adhesion inducing properties (RGD-functionalized PLL-g-PEG). Quantitative adhesion data was obtained by employing optical biochips and microscopy. Cell-adhesion-regulating coatings can be simply formed on hydrophobic surfaces by using the developed flagellin-based constructs. The developed novel RGD-displaying flagellin variants can be easily obtained by bacterial production and can serve as alternatives to create cell-adhesion-regulating biomimetic coatings. In the present work, we show for the first time that. Copyright © 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  9. MICROBIAL CELL-SURFACE HYDROPHOBICITY - THE INVOLVEMENT OF ELECTROSTATIC INTERACTIONS IN MICROBIAL ADHESION TO HYDROCARBONS (MATH)

    NARCIS (Netherlands)

    GEERTSEMADOORNBUSCH, GI; VANDERMEI, HC; BUSSCHER, HJ

    Microbial adhesion to hydrocarbons (MATH) is the most commonly used method to determine microbial cell surface hydrophobicity. Since, however, the assay is based on adhesion, it is questionable whether the results reflect only the cell surface hydrophobicity or an interplay of hydrophobicity and

  10. Ceramic hydroxyapatite coating on titanium implants drives selective bone marrow stromal cell adhesion.

    NARCIS (Netherlands)

    Torensma, R.; Brugge, P.J. ter; Jansen, J.A.; Figdor, C.G.

    2003-01-01

    The aim of this study was to determine the cell characteristics that regulate implant osseointegration. The heterogeneity of bone marrow stromal cells obtained from 11 donors was assessed by measuring the expression of a large panel of adhesion molecules. Large differences in expression of adhesion

  11. Combined effects of PEG hydrogel elasticity and cell-adhesive coating on fibroblast adhesion and persistent migration.

    Science.gov (United States)

    Missirlis, Dimitris; Spatz, Joachim P

    2014-01-13

    The development and use of synthetic, cross-linked, macromolecular substrates with tunable elasticity has been instrumental in revealing the mechanisms by which cells sense and respond to their mechanical microenvironment. We here describe a hydrogel based on radical-free, cross-linked poly(ethylene glycol) to study the effects of both substrate elasticity and type of adhesive coating on fibroblast adhesion and migration. Hydrogel elasticity was controlled through the structure and concentration of branched precursors, which efficiently react via Michael-type addition to produce the polymer network. We found that cell spreading and focal adhesion characteristics are dependent on elasticity for all types of coatings (RGD peptide, fibronectin, vitronectin), albeit with significant differences in magnitude. Importantly, fibroblasts migrated slower but more persistently on stiffer hydrogels, with the effects being more pronounced on fibronectin-coated substrates. Therefore, our results validate the hydrogels presented in this study as suitable for future mechanosensing studies and indicate that cell adhesion, polarity, and associated migration persistence are tuned by substrate elasticity and biochemical properties.

  12. Capillary network formation from dispersed endothelial cells: Influence of cell traction, cell adhesion, and extracellular matrix rigidity

    Science.gov (United States)

    Ramos, João R. D.; Travasso, Rui; Carvalho, João

    2018-01-01

    The formation of a functional vascular network depends on biological, chemical, and physical processes being extremely well coordinated. Among them, the mechanical properties of the extracellular matrix and cell adhesion are fundamental to achieve a functional network of endothelial cells, able to fully cover a required domain. By the use of a Cellular Potts Model and Finite Element Method it is shown that there exists a range of values of endothelial traction forces, cell-cell adhesion, and matrix rigidities where the network can spontaneously be formed, and its properties are characterized. We obtain the analytical relation that the minimum traction force required for cell network formation must obey. This minimum value for the traction force is approximately independent on the considered cell number and cell-cell adhesion. We quantify how these two parameters influence the morphology of the resulting networks (size and number of meshes).

  13. Data on the putative role of p53 in breast cancer cell adhesion: Technical information for adhesion assay

    Directory of Open Access Journals (Sweden)

    Kallirroi Voudouri

    2016-12-01

    Full Text Available In this data article, the potential role of p53 tumor suppressor gene (p53 on the attachment ability of MCF-7 breast cancer cells was investigated. In our main article, “IGF-I/ EGF and E2 signaling crosstalk through IGF-IR conduit point affect breast cancer cell adhesion” (K. Voudouri, D. Nikitovic, A. Berdiaki, D. Kletsas, N.K. Karamanos, G.N. Tzanakakis, 2016 [1], we describe the key role of IGF-IR in breast cancer cell adhesion onto fibronectin (FN. p53 tumor suppressor gene is a principal regulator of cancer cell proliferation. Various data have demonstrated an association between p53 and IGF-IR actions on cell growth through its’ putative regulation of IGF-IR expression. According to our performed experiments, p53 does not modify IGF-IR expression and does not affect basal MCF-7 cells adhesion onto FN. Moreover, technical details about the performance of adhesion assay onto the FN substrate were provided.

  14. Drug-induced in vitro inhibition of neutrophil-endothelial cell adhesion.

    Science.gov (United States)

    Pellegatta, F.; Lu, Y.; Radaelli, A.; Zocchi, M. R.; Ferrero, E.; Chierchia, S.; Gaja, G.; Ferrero, M. E.

    1996-01-01

    1. Leukocyte-endothelial cell interactions play an important role during ischaemia-reperfusion events. Adhesion molecules are specifically implicated in this interaction process. 2. Since defibrotide has been shown to be an efficient drug in reducing damage due to ischaemia-reperfusion in many experimental models, we analysed the effect of defibrotide in vitro on leukocyte adhesion to endothelial cells in basal conditions and after their stimulation. 3. In basal conditions, defibrotide (1000 micrograms ml-1) partially inhibited leukocyte adhesion to endothelial cells by 17.3% +/- 3.6 (P defibrotide. 5. This result was confirmed in NIH/3T3-ICAM-1 transfected cells. 6. We conclude that defibrotide is able to interfere with leukocyte adhesion to endothelial cells mainly in activated conditions and that the ICAM-1/LFA-1 adhesion system is involved in the defibrotide mechanism of action. PMID:8762067

  15. Protein kinase C, focal adhesions and the regulation of cell migration

    DEFF Research Database (Denmark)

    Fogh, Betina S; Multhaupt, Hinke A B; Couchman, John Robert

    2014-01-01

    in their intracellular compartment. Among these are tyrosine kinases, which have received a great deal of attention, whereas the serine/threonine kinase protein kinase C has received much less. Here the status of protein kinase C in focal adhesions and cell migration is reviewed, together with discussion of its roles...... and adhesion turnover. Focal adhesions, or focal contacts, are widespread organelles at the cell-matrix interface. They arise as a result of receptor interactions with matrix ligands, together with clustering. Recent analysis shows that focal adhesions contain a very large number of protein components...

  16. Fermented soya bean (tempe) extracts reduce adhesion of enterotoxigenic Escherichia coli to intestinal epithelial cells.

    Science.gov (United States)

    Roubos-van den Hil, P J; Nout, M J R; Beumer, R R; van der Meulen, J; Zwietering, M H

    2009-03-01

    This study aimed to investigate the effect of processed soya bean, during the successive stages of tempe fermentation and different fermentation times, on adhesion of enterotoxigenic Escherichia coli (ETEC) K88 to intestinal brush border cells as well as Caco-2 intestinal epithelial cells; and to clarify the mechanism of action. Tempe was prepared at controlled laboratory scale using Rhizopus microsporus var. microsporus as the inoculum. Extracts of raw, soaked and cooked soya beans reduced ETEC adhesion to brush border cells by 40%. Tempe extracts reduced adhesion by 80% or more. ETEC adhesion to Caco-2 cells reduced by 50% in the presence of tempe extracts. ETEC K88 bacteria were found to interact with soya bean extracts, and this may contribute to the observed decrease of ETEC adhesion to intestinal epithelial cells. Fermented soya beans (tempe) reduce the adhesion of ETEC to intestinal epithelial cells of pig and human origin. This reduced adhesion is caused by an interaction between ETEC K88 bacteria and soya bean compounds. The results strengthen previous observations on the anti-diarrhoeal effect of tempe. This effect indicates that soya-derived compounds may reduce adhesion of ETEC to intestinal cells in pigs as well as in humans and prevent against diarrhoeal diseases.

  17. Protein adhesives

    Science.gov (United States)

    Charles R. Frihart; Linda F. Lorenz

    2018-01-01

    Nature uses a wide variety of chemicals for providing adhesion internally (e.g., cell to cell) and externally (e.g., mussels to ships and piers). This adhesive bonding is chemically and mechanically complex, involving a variety of proteins, carbohydrates, and other compounds.Consequently,the effect of protein structures on adhesive properties is only partially...

  18. Regulation of epithelial and lymphocyte cell adhesion by adenosine deaminase-CD26 interaction.

    Science.gov (United States)

    Ginés, Silvia; Mariño, Marta; Mallol, Josefa; Canela, Enric I; Morimoto, Chikao; Callebaut, Christian; Hovanessian, Ara; Casadó, Vicent; Lluis, Carmen; Franco, Rafael

    2002-01-01

    The extra-enzymic function of cell-surface adenosine deaminase (ADA), an enzyme mainly localized in the cytosol but also found on the cell surface of monocytes, B cells and T cells, has lately been the subject of numerous studies. Cell-surface ADA is able to transduce co-stimulatory signals in T cells via its interaction with CD26, an integral membrane protein that acts as ADA-binding protein. The aim of the present study was to explore whether ADA-CD26 interaction plays a role in the adhesion of lymphocyte cells to human epithelial cells. To meet this aim, different lymphocyte cell lines (Jurkat and CEM T) expressing endogenous, or overexpressing human, CD26 protein were tested in adhesion assays to monolayers of colon adenocarcinoma human epithelial cells, Caco-2, which express high levels of cell-surface ADA. Interestingly, the adhesion of Jurkat and CEM T cells to a monolayer of Caco-2 cells was greatly dependent on CD26. An increase by 50% in the cell-to-cell adhesion was found in cells containing higher levels of CD26. Incubation with an anti-CD26 antibody raised against the ADA-binding site or with exogenous ADA resulted in a significant reduction (50-70%) of T-cell adhesion to monolayers of epithelial cells. The role of ADA-CD26 interaction in the lymphocyte-epithelial cell adhesion appears to be mediated by CD26 molecules that are not interacting with endogenous ADA (ADA-free CD26), since SKW6.4 (B cells) that express more cell-surface ADA showed lower adhesion than T cells. Adhesion stimulated by CD26 and ADA is mediated by T cell lymphocyte function-associated antigen. A role for ADA-CD26 interaction in cell-to-cell adhesion was confirmed further in integrin activation assays. FACS analysis revealed a higher expression of activated integrins on T cell lines in the presence of increasing amounts of exogenous ADA. Taken together, these results suggest that the ADA-CD26 interaction on the cell surface has a role in lymphocyte-epithelial cell adhesion. PMID

  19. The Molecular Architecture of Cell Adhesion: Dynamic Remodeling Revealed by Videonanoscopy

    Directory of Open Access Journals (Sweden)

    Arnauld eSergé

    2016-05-01

    Full Text Available The plasma membrane delimits the cell, which is the basic unit of living organisms, and is also a privileged site for cell communication with the environment. Cell adhesion can occur through cell-cell and cell-matrix contacts. Adhesion proteins such as integrins and cadherins also constitute receptors for inside-out and outside-in signaling within proteolipidic platforms. Adhesion molecule targeting and stabilization relies on specific features such as preferential segregation by the sub-membrane cytoskeleton meshwork and within membrane proteolipidic microdomains. This review presents an overview of the recent insights brought by the latest developments in microscopy, to unravel the molecular remodeling occurring at cell contacts. The dynamic aspect of cell adhesion was recently highlighted by super-resolution videomicroscopy, also named videonanoscopy. By circumventing the diffraction limit of light, nanoscopy has allowed the monitoring of molecular localization and behavior at the single-molecule level, on fixed and living cells. Accessing molecular-resolution details such as quantitatively monitoring components entering and leaving cell contacts by lateral diffusion and reversible association has revealed an unexpected plasticity. Adhesion structures can be highly specialized, such as focal adhesion in motile cells, as well as immune and neuronal synapses. Spatiotemporal reorganization of adhesion molecules, receptors and adaptors directly relates to structure/function modulation. Assembly of these supramolecular complexes is continuously balanced by dynamic events, remodeling adhesions on various timescales, notably by molecular conformation switches, lateral diffusion within the membrane and endo/exocytosis. Pathological alterations in cell adhesion are involved in cancer evolution, through cancer stem cell interaction with stromal niches, growth, extravasation and metastasis.

  20. Strong adhesion of Saos-2 cells to multi-walled carbon nanotubes

    International Nuclear Information System (INIS)

    Matsuoka, Makoto; Akasaka, Tsukasa; Totsuka, Yasunori; Watari, Fumio

    2010-01-01

    In recent years, carbon nanotubes (CNTs) have been considered potential biomedical materials because of their unique character. The aim of this study was to investigate the response of a human osteoblast-like cell line - Saos-2 - on single-walled CNTs (SWCNTs) and multi-walled CNTs (MWCNTs). The surface of a culture dish was coated with CNTs, and Saos-2 cells were cultured for three days. Cell morphology, viability, alkaline phosphatase (ALP) activity, adhesion, and vinculin expression were evaluated. The result showed high cell viability and strong adhesion to MWCNTs. Saos-2 cultured on MWCNTs exhibited vinculin expression throughout the cell body, while the cells attached to SWCNTs and glass were mostly limited to their periphery. Our results suggest that CNT coatings promote cell activity and adhesiveness. These findings indicate that MWCNTs could be used as surface coating materials to promote cell adhesion.

  1. Syndecan-4 and integrins: combinatorial signaling in cell adhesion

    DEFF Research Database (Denmark)

    Couchman, J R; Woods, A

    1999-01-01

    It is now becoming clear that additional transmembrane components can modify integrin-mediated adhesion. Syndecan-4 is a transmembrane heparan sulfate proteoglycan whose external glycosaminoglycan chains can bind extracellular matrix ligands and whose core protein cytoplasmic domain can signal...... during adhesion. Two papers in this issue of JCS demonstrate, through transfection studies, that syndecan-4 plays roles in the formation of focal adhesions and stress fibers. Overexpression of syndecan-4 increases focal adhesion formation, whereas a partially truncated core protein that lacks the binding...... site for protein kinase C(&agr;) and phosphatidylinositol 4, 5-bisphosphate acts as a dominant negative inhibitor of focal adhesion formation. Focal adhesion induction does not require interaction between heparan sulfate glycosaminoglycan and ligand but can occur when non-glycanated core protein...

  2. The coffee diterpene kahweol inhibits tumor necrosis factor-α-induced expression of cell adhesion molecules in human endothelial cells

    International Nuclear Information System (INIS)

    Kim, Hyung Gyun; Kim, Ji Young; Hwang, Yong Pil; Lee, Kyung Jin; Lee, Kwang Youl; Kim, Dong Hee; Kim, Dong Hyun; Jeong, Hye Gwang

    2006-01-01

    Endothelial cells produce adhesion molecules after being stimulated with various inflammatory cytokines. These adhesion molecules play an important role in the development of atherogenesis. Recent studies have highlighted the chemoprotective and anti-inflammatory effects of kahweol, a coffee-specific diterpene. This study examined the effects of kahweol on the cytokine-induced monocyte/human endothelial cell interaction, which is a crucial early event in atherogenesis. Kahweol inhibited the adhesion of TNFα-induced monocytes to endothelial cells and suppressed the TNFα-induced protein and mRNA expression of the cell adhesion molecules, VCAM-1 and ICAM-1. Furthermore, kahweol inhibited the TNFα-induced JAK2-PI3K/Akt-NF-κB activation pathway in these cells. Overall, kahweol has anti-inflammatory and anti-atherosclerotic activities, which occurs partly by down-regulating the pathway that affects the expression and interaction of the cell adhesion molecules on endothelial cells

  3. Homophilic and Heterophilic Interactions of Type II Cadherins Identify Specificity Groups Underlying Cell-Adhesive Behavior

    Directory of Open Access Journals (Sweden)

    Julia Brasch

    2018-05-01

    Full Text Available Summary: Type II cadherins are cell-cell adhesion proteins critical for tissue patterning and neuronal targeting but whose molecular binding code remains poorly understood. Here, we delineate binding preferences for type II cadherin cell-adhesive regions, revealing extensive heterophilic interactions between specific pairs, in addition to homophilic interactions. Three distinct specificity groups emerge from our analysis with members that share highly similar heterophilic binding patterns and favor binding to one another. Structures of adhesive fragments from each specificity group confirm near-identical dimer topology conserved throughout the family, allowing interface residues whose conservation corresponds to specificity preferences to be identified. We show that targeted mutation of these residues converts binding preferences between specificity groups in biophysical and co-culture assays. Our results provide a detailed understanding of the type II cadherin interaction map and a basis for defining their role in tissue patterning and for the emerging importance of their heterophilic interactions in neural connectivity. : Type II cadherins are a family of vertebrate cell adhesion proteins expressed primarily in the CNS. Brasch et al. measure binding between adhesive fragments, revealing homophilic and extensive selective heterophilic binding with specificities that define groups of similar cadherins. Structures reveal common adhesive dimers, with residues governing cell-adhesive specificity. Keywords: cell adhesion, crystal structure, hemophilic specificity, heterophilic specificity, neural patterning, synaptic targeting, cadherin

  4. Cell surface heparan sulfate proteoglycans control adhesion and invasion of breast carcinoma cells

    DEFF Research Database (Denmark)

    Lim, Hooi Ching; Multhaupt, Hinke A. B.; Couchman, John R.

    2015-01-01

    breast carcinoma. This may derive from their regulation of cell adhesion, but roles for specific syndecans are unresolved. Methods: The MDA-MB231 human breast carcinoma cell line was exposed to exogenous glycosaminoglycans and changes in cell behavior monitored by western blotting, immunocytochemistry......, invasion and collagen degradation assays. Selected receptors including PAR-1 and syndecans were depleted by siRNA treatments to assess cell morphology and behavior. Immunohistochemistry for syndecan-2 and its interacting partner, caveolin-2 was performed on human breast tumor tissue arrays. Two......-tailed paired t-test and one-way ANOVA with Tukey¿s post-hoc test were used in the analysis of data. Results: MDA-MB231 cells were shown to be highly sensitive to exogenous heparan sulfate or heparin, promoting increased spreading, focal adhesion and adherens junction formation with concomitantly reduced...

  5. Integrative systems and synthetic biology of cell-matrix adhesion sites.

    Science.gov (United States)

    Zamir, Eli

    2016-09-02

    The complexity of cell-matrix adhesion convolves its roles in the development and functioning of multicellular organisms and their evolutionary tinkering. Cell-matrix adhesion is mediated by sites along the plasma membrane that anchor the actin cytoskeleton to the matrix via a large number of proteins, collectively called the integrin adhesome. Fundamental challenges for understanding how cell-matrix adhesion sites assemble and function arise from their multi-functionality, rapid dynamics, large number of components and molecular diversity. Systems biology faces these challenges in its strive to understand how the integrin adhesome gives rise to functional adhesion sites. Synthetic biology enables engineering intracellular modules and circuits with properties of interest. In this review I discuss some of the fundamental questions in systems biology of cell-matrix adhesion and how synthetic biology can help addressing them.

  6. Adhesion, biofilm formation, cell surface hydrophobicity, and antifungal planktonic susceptibility: relationship among Candida spp.

    OpenAIRE

    Silva-Dias, Ana; Miranda, Isabel M.; Branco, Joana; Monteiro-Soares, Matilde; Pina-Vaz, Cid?lia; Rodrigues, Ac?cio G.

    2015-01-01

    We have performed the characterization of the adhesion profile, biofilm formation, cell surface hydrophobicity (CSH) and antifungal susceptibility of 184 Candida clinical isolates obtained from different human reservoirs. Adhesion was quantified using a flow cytometric assay and biofilm formation was evaluated using two methodologies: XTT and crystal violet assay. CSH was quantified with the microbial adhesion to hydrocarbons test while planktonic susceptibility was assessed accordingly the C...

  7. Glycosynapses: microdomains controlling carbohydrate-dependent cell adhesion and signaling

    Directory of Open Access Journals (Sweden)

    Senitiroh Hakomori

    2004-09-01

    Full Text Available The concept of microdomains in plasma membranes was developed over two decades, following observation of polarity of membrane based on clustering of specific membrane components. Microdomains involved in carbohydrate-dependent cell adhesion with concurrent signal transduction that affect cellular phenotype are termed "glycosynapse". Three types of glycosynapse have been distinguished: "type 1" having glycosphingolipid associated with signal transducers (small G-proteins, cSrc, Src family kinases and proteolipids; "type 2" having O-linked mucin-type glycoprotein associated with Src family kinases; and "type 3" having N-linked integrin receptor complexed with tetraspanin and ganglioside. Different cell types are characterized by presence of specific types of glycosynapse or their combinations, whose adhesion induces signal transduction to either facilitate or inhibit signaling. E.g., signaling through type 3 glycosynapse inhibits cell motility and differentiation. Glycosynapses are distinct from classically-known microdomains termed "caveolae", "caveolar membrane", or more recently "lipid raft", which are not involved in carbohydrate-dependent cell adhesion. Type 1 and type 3 glycosynapses are resistant to cholesterol-binding reagents, whereas structure and function of "caveolar membrane" or "lipid raft" are disrupted by these reagents. Various data indicate a functional role of glycosynapses during differentiation, development, and oncogenic transformation.O conceito de microdomínios em membrana plasmática foi desenvolvido há mais de duas décadas, após a observação da polaridade da membrana baseada no agrupamento de componentes específicos da membrana. Microdomínios envolvidos na adesão celular dependente de carboidrato, com transdução de sinal que afeta o fenótipo celular são denominados ''glicosinapses''. Três tipos de glicosinapse foram observados: ''tipo 1'' que possue glicoesfingolipídio associado com transdutores de sinal

  8. Th17 Cell Induction by Adhesion of Microbes to Intestinal Epithelial Cells.

    Science.gov (United States)

    Atarashi, Koji; Tanoue, Takeshi; Ando, Minoru; Kamada, Nobuhiko; Nagano, Yuji; Narushima, Seiko; Suda, Wataru; Imaoka, Akemi; Setoyama, Hiromi; Nagamori, Takashi; Ishikawa, Eiji; Shima, Tatsuichiro; Hara, Taeko; Kado, Shoichi; Jinnohara, Toshi; Ohno, Hiroshi; Kondo, Takashi; Toyooka, Kiminori; Watanabe, Eiichiro; Yokoyama, Shin-Ichiro; Tokoro, Shunji; Mori, Hiroshi; Noguchi, Yurika; Morita, Hidetoshi; Ivanov, Ivaylo I; Sugiyama, Tsuyoshi; Nuñez, Gabriel; Camp, J Gray; Hattori, Masahira; Umesaki, Yoshinori; Honda, Kenya

    2015-10-08

    Intestinal Th17 cells are induced and accumulate in response to colonization with a subgroup of intestinal microbes such as segmented filamentous bacteria (SFB) and certain extracellular pathogens. Here, we show that adhesion of microbes to intestinal epithelial cells (ECs) is a critical cue for Th17 induction. Upon monocolonization of germ-free mice or rats with SFB indigenous to mice (M-SFB) or rats (R-SFB), M-SFB and R-SFB showed host-specific adhesion to small intestinal ECs, accompanied by host-specific induction of Th17 cells. Citrobacter rodentium and Escherichia coli O157 triggered similar Th17 responses, whereas adhesion-defective mutants of these microbes failed to do so. Moreover, a mixture of 20 bacterial strains, which were selected and isolated from fecal samples of a patient with ulcerative colitis on the basis of their ability to cause a robust induction of Th17 cells in the mouse colon, also exhibited EC-adhesive characteristics. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Constitutive activation of BMP signalling abrogates experimental metastasis of OVCA429 cells via reduced cell adhesion

    Directory of Open Access Journals (Sweden)

    Shepherd Trevor G

    2010-02-01

    Full Text Available Abstract Background Activation of bone morphogenetic protein (BMP4 signalling in human ovarian cancer cells induces a number of phenotypic changes in vitro, including altered cell morphology, adhesion, motility and invasion, relative to normal human ovarian surface epithelial cells. From these in vitro analyses, we had hypothesized that active BMP signalling promotes the metastatic potential of ovarian cancer. Methods To test this directly, we engineered OVCA429 human ovarian cancer cells possessing doxycycline-inducible expression of a constitutively-active mutant BMP receptor, ALK3QD, and administered these cells to immunocompromised mice. Further characterization was performed in vitro to address the role of activated BMP signalling on the EOC phenotype, with particular emphasis on epithelial-mesenchymal transition (EMT and cell adhesion. Results Unexpectedly, doxycycline-induced ALK3QD expression in OVCA429 cells reduced tumour implantation on peritoneal surfaces and ascites formation when xenografted into immunocompromised mice by intraperitoneal injection. To determine the potential mechanisms controlling this in vivo observation, we followed with several cell culture experiments. Doxycycline-induced ALK3QD expression enhanced the refractile, spindle-shaped morphology of cultured OVCA429 cells eliciting an EMT-like response. Using in vitro wound healing assays, we observed that ALK3QD-expressing cells migrated with long, cytoplasmic projections extending into the wound space. The phenotypic alterations of ALK3QD-expressing cells correlated with changes in specific gene expression patterns of EMT, including increased Snail and Slug and reduced E-cadherin mRNA expression. In addition, ALK3QD signalling reduced β1- and β3-integrin expression, critical molecules involved in ovarian cancer cell adhesion. The combination of reduced E-cadherin and β-integrin expression correlates directly with the reduced EOC cell cohesion in spheroids and

  10. A role for cell adhesion in beryllium-mediated lung disease

    Energy Technology Data Exchange (ETDEWEB)

    Hong-geller, Elizabeth [Los Alamos National Laboratory

    2008-01-01

    Chronic beryllium disease (CBD) is a debilitating lung disorder in which exposure to the lightweight metal beryllium (Be) causes the accumulation of beryllium-specific CD4+ T cells in the lung and formation of noncaseating pulmonary granulomas. Treatment for CBD patients who exhibit progressive pulmonary decline is limited to systemic corticosteroids, which suppress the severe host inflammatory response. Studies in the past several years have begun to highlight cell-cell adhesion interactions in the development of Be hypersensitivity and CBD. In particular, the high binding affinity between intercellular adhesion molecule 1 (I-CAM1) on lung epithelial cells and the {beta}{sub 2} integrin LFA-1 on migrating lymphocytes and macrophages regulates the concerted rolling of immune cells to sites of inflammation in the lung. In this review, we discuss the evidence that implicates cell adhesion processes in onset of Be disease and the potential of cell adhesion as an intervention point for development of novel therapies.

  11. Probing cellular mechanoadaptation using cell-substrate de-adhesion dynamics: experiments and model.

    Science.gov (United States)

    S S, Soumya; Sthanam, Lakshmi Kavitha; Padinhateeri, Ranjith; Inamdar, Mandar M; Sen, Shamik

    2014-01-01

    Physical properties of the extracellular matrix (ECM) are known to regulate cellular processes ranging from spreading to differentiation, with alterations in cell phenotype closely associated with changes in physical properties of cells themselves. When plated on substrates of varying stiffness, fibroblasts have been shown to exhibit stiffness matching property, wherein cell cortical stiffness increases in proportion to substrate stiffness up to 5 kPa, and subsequently saturates. Similar mechanoadaptation responses have also been observed in other cell types. Trypsin de-adhesion represents a simple experimental framework for probing the contractile mechanics of adherent cells, with de-adhesion timescales shown to scale inversely with cortical stiffness values. In this study, we combine experiments and computation in deciphering the influence of substrate properties in regulating de-adhesion dynamics of adherent cells. We first show that NIH 3T3 fibroblasts cultured on collagen-coated polyacrylamide hydrogels de-adhere faster on stiffer substrates. Using a simple computational model, we qualitatively show how substrate stiffness and cell-substrate bond breakage rate collectively influence de-adhesion timescales, and also obtain analytical expressions of de-adhesion timescales in certain regimes of the parameter space. Finally, by comparing stiffness-dependent experimental and computational de-adhesion responses, we show that faster de-adhesion on stiffer substrates arises due to force-dependent breakage of cell-matrix adhesions. In addition to illustrating the utility of employing trypsin de-adhesion as a biophysical tool for probing mechanoadaptation, our computational results highlight the collective interplay of substrate properties and bond breakage rate in setting de-adhesion timescales.

  12. Wet-chemical approach for the cell-adhesive modification of polytetrafluoroethylene

    International Nuclear Information System (INIS)

    Gabriel, Matthias; Dahm, Manfred; Vahl, Christian-F

    2011-01-01

    Polytetrafluoroethylene (PTFE), a frequently utilized polymer for the fabrication of synthetic vascular grafts, was surface-modified by means of a wet-chemical process. The inherently non-cell-adhesive polymer does not support cellular attachment, a prerequisite for the endothelialization of luminal surface grafts in small diameter applications. To impart the material with cell-adhesive properties a treatment with sodium-naphthalene provided a basis for the subsequent immobilization of the adhesion promoting RGD-peptide using a hydroxy- and amine-reactive crosslinker. Successful conjugation was shown with cell culture experiments which demonstrated excellent endothelial cell growth on the modified surfaces.

  13. SU-8 hollow cantilevers for AFM cell adhesion studies

    Science.gov (United States)

    Martinez, Vincent; Behr, Pascal; Drechsler, Ute; Polesel-Maris, Jérôme; Potthoff, Eva; Vörös, Janos; Zambelli, Tomaso

    2016-05-01

    A novel fabrication method was established to produce flexible, transparent, and robust tipless hollow atomic force microscopy (AFM) cantilevers made entirely from SU-8. Channels of 3 μm thickness and several millimeters length were integrated into 12 μm thick and 40 μm wide cantilevers. Connected to a pressure controller, the devices showed high sealing performance with no leakage up to 6 bars. Changing the cantilever lengths from 100 μm to 500 μm among the same wafer allowed the targeting of various spring constants ranging from 0.5 to 80 N m-1 within a single fabrication run. These hollow polymeric AFM cantilevers were operated in the optical beam deflection configuration. To demonstrate the performance of the device, single-cell force spectroscopy experiments were performed with a single probe detaching in a serial protocol more than 100 Saccharomyces cerevisiae yeast cells from plain glass and glass coated with polydopamine while measuring adhesion forces in the sub-nanoNewton range. SU-8 now offers a new alternative to conventional silicon-based hollow cantilevers with more flexibility in terms of complex geometric design and surface chemistry modification.

  14. SU-8 hollow cantilevers for AFM cell adhesion studies

    International Nuclear Information System (INIS)

    Martinez, Vincent; Behr, Pascal; Vörös, Janos; Zambelli, Tomaso; Drechsler, Ute; Polesel-Maris, Jérôme; Potthoff, Eva

    2016-01-01

    A novel fabrication method was established to produce flexible, transparent, and robust tipless hollow atomic force microscopy (AFM) cantilevers made entirely from SU-8. Channels of 3 μm thickness and several millimeters length were integrated into 12 μm thick and 40 μm wide cantilevers. Connected to a pressure controller, the devices showed high sealing performance with no leakage up to 6 bars. Changing the cantilever lengths from 100 μm to 500 μm among the same wafer allowed the targeting of various spring constants ranging from 0.5 to 80 N m −1 within a single fabrication run. These hollow polymeric AFM cantilevers were operated in the optical beam deflection configuration. To demonstrate the performance of the device, single-cell force spectroscopy experiments were performed with a single probe detaching in a serial protocol more than 100 Saccharomyces cerevisiae yeast cells from plain glass and glass coated with polydopamine while measuring adhesion forces in the sub-nanoNewton range. SU-8 now offers a new alternative to conventional silicon-based hollow cantilevers with more flexibility in terms of complex geometric design and surface chemistry modification. (paper)

  15. Research on effects of ionizing radiation of human peripheral blood white cell adhesive molecules

    International Nuclear Information System (INIS)

    Li Haijun; Cheng Ying; Le Chen; Min Rui

    2008-01-01

    Objective: To investigate the links between expression and function of adhesive molecule on the surface of irradiated peripheral blood white cells. Methods: Heparinized human peripheral blood was exposed to γ rays with different dose. At the different post-radiation time adhesive molecule expression on cellular surface was determined by double fluorescence labeling antibodies which were against adhesive molecule and special mark of granulocyte or mononuclear cell respectively with flow cytometry, and cellular adhesive ability to different matrixes mediated by adhesive molecule was estimated by commercializing enzyme-linked immunosorbent assay kit and crystalviolet dying. Results: A decline pattern of CD11b on surface of mononuclear cells and CD29 on surface of granulocyte with irradiation dose increase was found. The changes of adhesive ability of mononuclear cells to substance of β1-integrin and collagen-I was well related with irradiation dose. Conclusion: Good relationship shown by the changes of adhesive molecule expression and adhesive ability mediated by the molecules on the surface of peripheral blood white cells with radiation dose was primary base of further research on indicting exposure dose by biomarker. (authors)

  16. Adhesion of some probiotic and dairy Lactobacillus strains to Caco-2 cell cultures.

    Science.gov (United States)

    Tuomola, E M; Salminen, S J

    1998-05-05

    The adhesion of 12 different Lactobacillus strains was studied using Caco-2 cell line as an in vitro model for intestinal epithelium. Some of the strains tested have been used as probiotics, and most of them are used in the dairy and food industry. Human and bovine enterotoxigenic Escherichia coli strains were used as positive and negative control, respectively. Bacterial adhesion to Caco-2 cell cultures was quantitated using radiolabelled bacteria. The adherence of bacteria was also observed microscopically after Gram staining. Viability of bacteria prior to adhesion was verified using flow cytometry. Among the tested strains, L. casei (Fyos) was the most adhesive strain and L. casei var. rhamnosus (Lactophilus) was the least adhesive strain, approximately 14 and 3% of the added bacteria adhered to Caco-2 cell cultures, respectively. The corresponding values for positive and negative control E. coli strains were 14 and 4%, respectively. The Lactobacillus strains tested could not be divided into distinctly adhesive or non-adhesive strains, since there was a continuation of adhesion rates. The four most adhesive strains were L. casei (Fyos), L. acidophilus 1 (LC1), L. rhamnosus LC-705 and Lactobacillus GG (ATCC 53103). No significant differences in the percentage adhesion were observed between these strains. Adhesion of all the strains was dependent on the number of bacteria used, since an approximately constant number of Caco-2 cells was used, indicating that the Caco-2 cell binding sites were not saturated. Viability of bacteria was high since approximately 90% of the bacteria were viable with the exception of L. acidophilus 1 which was 74% viable. Microscopic evaluations agreed with the radiolabelled binding as evidenced by observing more bacteria in Gram-stained preparations of good adhering strains compared to poorly adhering strains.

  17. The evaluation of p,p'-DDT exposure on cell adhesion of hepatocellular carcinoma.

    Science.gov (United States)

    Jin, Xiaoting; Chen, Meilan; Song, Li; Li, Hanqing; Li, Zhuoyu

    2014-08-01

    Many studies have found a positive association between the progression of hepatocellular carcinoma and DDT exposure. These studies mainly focus on the effect of DDT exposure on cell proliferation and epithelial to mesenchymal transition (EMT) promotion. However, the influence of DDT on cell adhesion of hepatocellular carcinoma remains to be unclear. The aim of our study was to determine the effect of p,p'-DDT on cell adhesion of hepatocellular carcinoma in vitro and in vivo. The data showed that p,p'-DDT, exposing HepG2 cells for 6 days, decreased cell-cell adhesion and elevated cell-matrix adhesion. Strikingly, p,p'-DDT increased reactive oxygen species (ROS) content, and this was accompanied by the activation of JAK/STAT3 pathway. Moreover, ROS inhibitor supplement reversed these effects significantly. However, the addition of ER inhibitor, ICI, had no effect on the p,p'-DDT-induced effects. p,p'-DDT altered the mRNA levels of related adhesion molecules, including inhibition of E-cadherin and promotion of N-cadherin along with CD29. Interestingly, the p,p'-DDT-altered adhesion molecules could be reversed with JAK inhibitor or STAT3 inhibitor. Likewise, p,p'-DDT stimulated the JAK/STAT3 pathway in nude mice, as well as altered the mRNA levels of E-cadherin, N-cadherin, and CD29. Taken together, these results indicate that p,p'-DDT profoundly promotes the adhesion process by decreasing cell-cell adhesion and inducing cell-matrix adhesion via the ROS-mediated JAK/STAT3 pathway. All these events account for the carcinogenic potential of p,p'-DDT in liver. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  18. An Evolutionary-Conserved Function of Mammalian Notch Family Members as Cell Adhesion Molecules

    Science.gov (United States)

    Murata, Akihiko; Yoshino, Miya; Hikosaka, Mari; Okuyama, Kazuki; Zhou, Lan; Sakano, Seiji; Yagita, Hideo; Hayashi, Shin-Ichi

    2014-01-01

    Notch family members were first identified as cell adhesion molecules by cell aggregation assays in Drosophila studies. However, they are generally recognized as signaling molecules, and it was unclear if their adhesion function was restricted to Drosophila. We previously demonstrated that a mouse Notch ligand, Delta-like 1 (Dll1) functioned as a cell adhesion molecule. We here investigated whether this adhesion function was conserved in the diversified mammalian Notch ligands consisted of two families, Delta-like (Dll1, Dll3 and Dll4) and Jagged (Jag1 and Jag2). The forced expression of mouse Dll1, Dll4, Jag1, and Jag2, but not Dll3, on stromal cells induced the rapid and enhanced adhesion of cultured mast cells (MCs). This was attributed to the binding of Notch1 and Notch2 on MCs to each Notch ligand on the stromal cells themselves, and not the activation of Notch signaling. Notch receptor-ligand binding strongly supported the tethering of MCs to stromal cells, the first step of cell adhesion. However, the Jag2-mediated adhesion of MCs was weaker and unlike other ligands appeared to require additional factor(s) in addition to the receptor-ligand binding. Taken together, these results demonstrated that the function of cell adhesion was conserved in mammalian as well as Drosophila Notch family members. Since Notch receptor-ligand interaction plays important roles in a broad spectrum of biological processes ranging from embryogenesis to disorders, our finding will provide a new perspective on these issues from the aspect of cell adhesion. PMID:25255288

  19. Cell adhesion monitoring of human induced pluripotent stem cell based on intrinsic molecular charges

    Science.gov (United States)

    Sugimoto, Haruyo; Sakata, Toshiya

    2014-01-01

    We have shown a simple way for real-time, quantitative, non-invasive, and non-label monitoring of human induced pluripotent stem (iPS) cell adhesion by use of a biologically coupled-gate field effect transistor (bio-FET), which is based on detection of molecular charges at cell membrane. The electrical behavior revealed quantitatively the electrical contacts of integrin-receptor at the cell membrane with RGDS peptide immobilized at the gate sensing surface, because that binding site was based on cationic α chain of integrin. The platform based on the bio-FET would provide substantial information to evaluate cell/material bio-interface and elucidate biding mechanism of adhesion molecules, which could not be interpreted by microscopic observation.

  20. Osteopontin adsorption to Gram-positive cells reduces adhesion forces and attachment to surfaces under flow

    DEFF Research Database (Denmark)

    Kristensen, M F; Zeng, G; Neu, T R

    2017-01-01

    caries or medical device-related infections. It further investigated if OPN's effect on adhesion is caused by blocking the accessibility of glycoconjugates on bacterial surfaces. Bacterial adhesion was determined in a shear-controlled flow cell system in the presence of different concentrations of OPN......The bovine milk protein osteopontin (OPN) may be an efficient means to prevent bacterial adhesion to dental tissues and control biofilm formation. This study sought to determine to what extent OPN impacts adhesion forces and surface attachment of different bacterial strains involved in dental......, and interaction forces of single bacteria were quantified using single-cell force spectroscopy before and after OPN exposure. Moreover, the study investigated OPN's effect on the accessibility of cell surface glycoconjugates through fluorescence lectin-binding analysis. OPN strongly affected bacterial adhesion...

  1. Surface free energy predominates in cell adhesion to hydroxyapatite through wettability.

    Science.gov (United States)

    Nakamura, Miho; Hori, Naoko; Ando, Hiroshi; Namba, Saki; Toyama, Takeshi; Nishimiya, Nobuyuki; Yamashita, Kimihiro

    2016-05-01

    The initial adhesion of cells to biomaterials is critical in the regulation of subsequent cell behaviors. The purpose of this study was to investigate a mechanism through which the surface wettability of biomaterials can be improved and determine the effects of biomaterial surface characteristics on cellular behaviors. We investigated the surface characteristics of various types of hydroxyapatite after sintering in different atmospheres and examined the effects of various surface characteristics on cell adhesion to study cell-biomaterial interactions. Sintering atmosphere affects the polarization capacity of hydroxyapatite by changing hydroxide ion content and grain size. Compared with hydroxyapatite sintered in air, hydroxyapatite sintered in saturated water vapor had a higher polarization capacity that increased surface free energy and improved wettability, which in turn accelerated cell adhesion. We determined the optimal conditions of hydroxyapatite polarization for the improvement of surface wettability and acceleration of cell adhesion. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Short Peptides Enhance Single Cell Adhesion and Viability onMicroarrays

    Energy Technology Data Exchange (ETDEWEB)

    Veiseh, Mandana; Veiseh, Omid; Martin, Michael C.; Asphahani,Fareid; Zhang, Miqin

    2007-01-19

    Single cell patterning holds important implications forbiology, biochemistry, biotechnology, medicine, and bioinformatics. Thechallenge for single cell patterning is to produce small islands hostingonly single cells and retaining their viability for a prolonged period oftime. This study demonstrated a surface engineering approach that uses acovalently bound short peptide as a mediator to pattern cells withimproved single cell adhesion and prolonged cellular viabilityon goldpatterned SiO2 substrates. The underlying hypothesis is that celladhesion is regulated bythe type, availability, and stability ofeffective cell adhesion peptides, and thus covalently bound shortpeptides would promote cell spreading and, thus, single cell adhesion andviability. The effectiveness of this approach and the underlyingmechanism for the increased probability of single cell adhesion andprolonged cell viability by short peptides were studied by comparingcellular behavior of human umbilical cord vein endothelial cells on threemodelsurfaces whose gold electrodes were immobilized with fibronectin,physically adsorbed Arg-Glu-Asp-Val-Tyr, and covalently boundLys-Arg-Glu-Asp-Val-Tyr, respectively. The surface chemistry and bindingproperties were characterized by reflectance Fourier transform infraredspectroscopy. Both short peptides were superior to fibronectin inproducing adhesion of only single cells, whereas the covalently boundpeptide also reduced apoptosis and necrosisof adhered cells. Controllingcell spreading by peptide binding domains to regulate apoptosis andviability represents a fundamental mechanism in cell-materialsinteraction and provides an effective strategy in engineering arrays ofsingle cells.

  3. Cell polarity, cell adhesion, and spermatogenesis: role of cytoskeletons [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Linxi Li

    2017-08-01

    Full Text Available In the rat testis, studies have shown that cell polarity, in particular spermatid polarity, to support spermatogenesis is conferred by the coordinated efforts of the Par-, Crumbs-, and Scribble-based polarity complexes in the seminiferous epithelium. Furthermore, planar cell polarity (PCP is conferred by PCP proteins such as Van Gogh-like 2 (Vangl2 in the testis. On the other hand, cell junctions at the Sertoli cell–spermatid (steps 8–19 interface are exclusively supported by adhesion protein complexes (for example, α6β1-integrin-laminin-α3,β3,γ3 and nectin-3-afadin at the actin-rich apical ectoplasmic specialization (ES since the apical ES is the only anchoring device in step 8–19 spermatids. For cell junctions at the Sertoli cell–cell interface, they are supported by adhesion complexes at the actin-based basal ES (for example, N-cadherin-β-catenin and nectin-2-afadin, tight junction (occludin-ZO-1 and claudin 11-ZO-1, and gap junction (connexin 43-plakophilin-2 and also intermediate filament-based desmosome (for example, desmoglein-2-desmocollin-2. In short, the testis-specific actin-rich anchoring device known as ES is crucial to support spermatid and Sertoli cell adhesion. Accumulating evidence has shown that the Par-, Crumbs-, and Scribble-based polarity complexes and the PCP Vangl2 are working in concert with actin- or microtubule-based cytoskeletons (or both and these polarity (or PCP protein complexes exert their effects through changes in the organization of the cytoskeletal elements across the seminiferous epithelium of adult rat testes. As such, there is an intimate relationship between cell polarity, cell adhesion, and cytoskeletal function in the testis. Herein, we critically evaluate these recent findings based on studies on different animal models. We also suggest some crucial future studies to be performed.

  4. Adhesion of cultured human endothelial cells onto methacrylate polymers with varying surface wettability and charge

    NARCIS (Netherlands)

    van Wachem, P.B.; Hogt, A.H.; Beugeling, T.; Feijen, Jan; Bantjes, A.; Detmers, J.P.; van Aken, W.G.

    1987-01-01

    The adhesion of human endothelial cells (HEC) onto a series of well-characterized methacrylate polymer surfaces with varying wettabilities and surface charges was studied either in serum-containing (CMS) or in serum-free (CM) culture medium. HEC adhesion in CMS onto (co)polymers * of hydroxyethyl

  5. Activation of AMP-activated protein kinase attenuates hepatocellular carcinoma cell adhesion stimulated by adipokine resistin

    International Nuclear Information System (INIS)

    Yang, Chen-Chieh; Chang, Shun-Fu; Chao, Jian-Kang; Lai, Yi-Liang; Chang, Wei-En; Hsu, Wen-Hsiu; Kuo, Wu-Hsien

    2014-01-01

    Resistin, adipocyte-secreting adipokine, may play critical role in modulating cancer pathogenesis. The aim of this study was to investigate the effects of resistin on HCC adhesion to the endothelium, and the mechanism underlying these resistin effects. Human SK-Hep1 cells were used to study the effect of resistin on intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) expressions as well as NF-κB activation, and hence cell adhesion to human umbilical vein endothelial cells (HUVECs). 5-Aminoimidazole-4-carboxamide 1-β-D-ribofuranoside (AICAR), an AMP-activated protein kinase (AMPK) activator, was used to determine the regulatory role of AMPK on HCC adhesion to the endothelium in regard to the resistin effects. Treatment with resistin increased the adhesion of SK-Hep1 cells to HUVECs and concomitantly induced NF-κB activation, as well as ICAM-1 and VCAM-1 expressions in SK-Hep1 cells. Using specific blocking antibodies and siRNAs, we found that resistin-induced SK-Hep1 cell adhesion to HUVECs was through NF-κB-regulated ICAM-1 and VCAM-1 expressions. Moreover, treatment with AICAR demonstrated that AMPK activation in SK-Hep1 cells significantly attenuates the resistin effect on SK-Hep1 cell adhesion to HUVECs. These results clarify the role of resistin in inducing HCC adhesion to the endothelium and demonstrate the inhibitory effect of AMPK activation under the resistin stimulation. Our findings provide a notion that resistin play an important role to promote HCC metastasis and implicate AMPK may be a therapeutic target to against HCC metastasis

  6. The evaluation of p,p′-DDT exposure on cell adhesion of hepatocellular carcinoma

    International Nuclear Information System (INIS)

    Jin, Xiaoting; Chen, Meilan; Song, Li; Li, Hanqing; Li, Zhuoyu

    2014-01-01

    Graphical abstract: - Highlights: • Low doses p,p′-DDT exposure disrupts cell–cell adhesion and cell–matrix adhesion in HepG2 cells. • Both oxidative stress and JAK/STAT3 pathway are activated in p,p′-DDT-treated HepG2 cells. • The stimulation of JAK/STAT3 pathway is mediated by oxidative stress. • p,p′-DDT regulates adhesion molecules via the JAK/STAT3 pathway. • p,p′-DDT stimulates JAK/STAT3 signal pathway and disrupts the expressions of cell adhesion molecules in nude mice models. - Abstract: Many studies have found a positive association between the progression of hepatocellular carcinoma and DDT exposure. These studies mainly focus on the effect of DDT exposure on cell proliferation and epithelial to mesenchymal transition (EMT) promotion. However, the influence of DDT on cell adhesion of hepatocellular carcinoma remains to be unclear. The aim of our study was to determine the effect of p,p′-DDT on cell adhesion of hepatocellular carcinoma in vitro and in vivo. The data showed that p,p′-DDT, exposing HepG2 cells for 6 days, decreased cell–cell adhesion and elevated cell–matrix adhesion. Strikingly, p,p′-DDT increased reactive oxygen species (ROS) content, and this was accompanied by the activation of JAK/STAT3 pathway. Moreover, ROS inhibitor supplement reversed these effects significantly. However, the addition of ER inhibitor, ICI, had no effect on the p,p′-DDT-induced effects. p,p′-DDT altered the mRNA levels of related adhesion molecules, including inhibition of E-cadherin and promotion of N-cadherin along with CD29. Interestingly, the p,p′-DDT-altered adhesion molecules could be reversed with JAK inhibitor or STAT3 inhibitor. Likewise, p,p′-DDT stimulated the JAK/STAT3 pathway in nude mice, as well as altered the mRNA levels of E-cadherin, N-cadherin, and CD29. Taken together, these results indicate that p,p′-DDT profoundly promotes the adhesion process by decreasing cell–cell adhesion and inducing cell

  7. Cellular contractility and substrate elasticity: a numerical investigation of the actin cytoskeleton and cell adhesion.

    Science.gov (United States)

    Ronan, William; Deshpande, Vikram S; McMeeking, Robert M; McGarry, J Patrick

    2014-04-01

    Numerous experimental studies have established that cells can sense the stiffness of underlying substrates and have quantified the effect of substrate stiffness on stress fibre formation, focal adhesion area, cell traction, and cell shape. In order to capture such behaviour, the current study couples a mixed mode thermodynamic and mechanical framework that predicts focal adhesion formation and growth with a material model that predicts stress fibre formation, contractility, and dissociation in a fully 3D implementation. Simulations reveal that SF contractility plays a critical role in the substrate-dependent response of cells. Compliant substrates do not provide sufficient tension for stress fibre persistence, causing dissociation of stress fibres and lower focal adhesion formation. In contrast, cells on stiffer substrates are predicted to contain large amounts of dominant stress fibres. Different levels of cellular contractility representative of different cell phenotypes are found to alter the range of substrate stiffness that cause the most significant changes in stress fibre and focal adhesion formation. Furthermore, stress fibre and focal adhesion formation evolve as a cell spreads on a substrate and leading to the formation of bands of fibres leading from the cell periphery over the nucleus. Inhibiting the formation of FAs during cell spreading is found to limit stress fibre formation. The predictions of this mutually dependent material-interface framework are strongly supported by experimental observations of cells adhered to elastic substrates and offer insight into the inter-dependent biomechanical processes regulating stress fibre and focal adhesion formation.

  8. Ochratoxim A alters cell adhesion and gap junction intercellular communication in MDCK cells

    International Nuclear Information System (INIS)

    Mally, Angela; Decker, Martina; Bekteshi, Michaela; Dekant, Wolfgang

    2006-01-01

    Ochratoxin A (OTA) is one of the most potent renal carcinogens studied to date, but the mechanism of tumor formation by ochratoxin A remains largely unknown. Cell adhesion and cell-cell communication participate in the regulation of signaling pathways involved in cell proliferation and growth control and it is therefore not surprising that modulation of cell-cell signaling has been implicated in cancer development. Several nephrotoxicants and renal carcinogens have been shown to alter cell-cell signaling by interference with gap junction intercell communication (GJIC) and/or cell adhesion, and the aim of this study was to determine if disruption of cell-cell interactions occurs in kidney epithelial cells in response to OTA treatment. MDCK cells were treated with OTA (0-50 μM) for up to 24 h and gap junction function was analyzed using the scrape-load/dye transfer assay. In addition, expression and intracellular localization of Cx43, E-cadherin and β-catenin were determined by immunoblot and immunofluorescence analysis. A clear decrease in the distance of dye transfer was evident following treatment with OTA at concentrations/incubation times which did not affect cell viability. Consistent with the functional inhibition of GJIC, treatment with OTA resulted in a dose-dependent decrease in Cx43 expression. In contrast to Cx43, OTA did not alter total amount of the adherens junction proteins E-cadherin and β-catenin. Moreover, Western blot analysis of Triton X-100 soluble and insoluble protein fractions did not indicate translocation of cell adhesion molecules from the membrane to the cytoplasm. However, a ∼78 kDa fragment of β-catenin was detected in the detergent soluble fraction, indicating proteolytic cleavage of β-catenin. Immunofluorescence analysis also revealed changes in the pattern of both β-catenin and E-cadherin labeling, suggesting that OTA may alter cell-adhesion. Taken together, these data support the hypothesis that disruption of cell-cell

  9. Heparanase facilitates cell adhesion and spreading by clustering of cell surface heparan sulfate proteoglycans.

    Directory of Open Access Journals (Sweden)

    Flonia Levy-Adam

    2008-06-01

    Full Text Available Heparanase is a heparan sulfate (HS degrading endoglycosidase participating in extracellular matrix degradation and remodeling. Apart of its well characterized enzymatic activity, heparanase was noted to exert also enzymatic-independent functions. Non-enzymatic activities of heparanase include enhanced adhesion of tumor-derived cells and primary T-cells. Attempting to identify functional domains of heparanase that would serve as targets for drug development, we have identified heparin binding domains of heparanase. A corresponding peptide (residues Lys(158-Asp(171, termed KKDC was demonstrated to physically associate with heparin and HS, and to inhibit heparanase enzymatic activity. We hypothesized that the pro-adhesive properties of heparanase are mediated by its interaction with cell surface HS proteoglycans, and utilized the KKDC peptide to examine this possibility. We provide evidence that the KKDC peptide interacts with cell membrane HS, resulting in clustering of syndecan-1 and syndecan-4. We applied classical analysis of cell morphology, fluorescent and time-lapse microscopy and demonstrated that the KKDC peptide efficiently stimulates the adhesion and spreading of various cell types, mediated by PKC, Src, and the small GTPase Rac1. These results support, and further substantiate the notion that heparanase function is not limited to its enzymatic activity.

  10. Single-cell force spectroscopy as a technique to quantify human red blood cell adhesion to subendothelial laminin.

    Science.gov (United States)

    Maciaszek, Jamie L; Partola, Kostyantyn; Zhang, Jing; Andemariam, Biree; Lykotrafitis, George

    2014-12-18

    Single-cell force spectroscopy (SCFS), an atomic force microscopy (AFM)-based assay, enables quantitative study of cell adhesion while maintaining the native state of surface receptors in physiological conditions. Human healthy and pathological red blood cells (RBCs) express a large number of surface proteins which mediate cell-cell interactions, or cell adhesion to the extracellular matrix. In particular, RBCs adhere with high affinity to subendothelial matrix laminin via the basal cell adhesion molecule and Lutheran protein (BCAM/Lu). Here, we established SCFS as an in vitro technique to study human RBC adhesion at baseline and following biochemical treatment. Using blood obtained from healthy human subjects, we recorded adhesion forces from single RBCs attached to AFM cantilevers as the cell was pulled-off of substrates coated with laminin protein. We found that an increase in the overall cell adhesion measured via SCFS is correlated with an increase in the resultant total force measured on 1 µm(2) areas of the RBC membrane. Further, we showed that SCFS can detect significant changes in the adhesive response of RBCs to modulation of the cyclic adenosine monophosphate (cAMP) and protein kinase A (PKA) pathway. Lastly, we identified variability in the RBC adhesion force to laminin amongst the human subjects, suggesting that RBCs maintain diverse levels of active BCAM/Lu adhesion receptors. By using single-cell measurements, we established a powerful new method for the quantitative measurement of single RBC adhesion with specific receptor-mediated binding. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Redundant control of migration and adhesion by ERM proteins in vascular smooth muscle cells

    International Nuclear Information System (INIS)

    Baeyens, Nicolas; Latrache, Iman; Yerna, Xavier; Noppe, Gauthier; Horman, Sandrine; Morel, Nicole

    2013-01-01

    Highlights: •The three ERM proteins are expressed in vascular smooth muscle cell. •ERM depletion inhibited PDGF-evoked migration redundantly. •ERM depletion increased cell adhesion redundantly. •ERM depletion did not affect PDGF-evoked Ca signal, Rac1 activation, proliferation. •ERM proteins control PDGF-induced migration by regulating adhesion. -- Abstract: Ezrin, radixin, and moesin possess a very similar structure with a C-terminal actin-binding domain and a N-terminal FERM interacting domain. They are known to be involved in cytoskeleton organization in several cell types but their function in vascular smooth muscle cells (VSMC) is still unknown. The aim of this study was to investigate the role of ERM proteins in cell migration induced by PDGF, a growth factor involved in pathophysiological processes like angiogenesis or atherosclerosis. We used primary cultured VSMC obtained from rat aorta, which express the three ERM proteins. Simultaneous depletion of the three ERM proteins with specific siRNAs abolished the effects of PDGF on cell architecture and migration and markedly increased cell adhesion and focal adhesion size, while these parameters were only slightly affected by depletion of ezrin, radixin or moesin alone. Rac1 activation, cell proliferation, and Ca 2+ signal in response to PDGF were unaffected by ERM depletion. These results indicate that ERM proteins exert a redundant control on PDGF-induced VSMC migration by regulating focal adhesion turn-over and cell adhesion to substrate

  12. Redundant control of migration and adhesion by ERM proteins in vascular smooth muscle cells

    Energy Technology Data Exchange (ETDEWEB)

    Baeyens, Nicolas; Latrache, Iman; Yerna, Xavier [Laboratory of Cell Physiology, IoNS, Université Catholique de Louvain (Belgium); Noppe, Gauthier; Horman, Sandrine [Pôle de Recherche Cardiovasculaire, IREC, Université Catholique de Louvain (Belgium); Morel, Nicole, E-mail: nicole.morel@uclouvain.be [Laboratory of Cell Physiology, IoNS, Université Catholique de Louvain (Belgium)

    2013-11-22

    Highlights: •The three ERM proteins are expressed in vascular smooth muscle cell. •ERM depletion inhibited PDGF-evoked migration redundantly. •ERM depletion increased cell adhesion redundantly. •ERM depletion did not affect PDGF-evoked Ca signal, Rac1 activation, proliferation. •ERM proteins control PDGF-induced migration by regulating adhesion. -- Abstract: Ezrin, radixin, and moesin possess a very similar structure with a C-terminal actin-binding domain and a N-terminal FERM interacting domain. They are known to be involved in cytoskeleton organization in several cell types but their function in vascular smooth muscle cells (VSMC) is still unknown. The aim of this study was to investigate the role of ERM proteins in cell migration induced by PDGF, a growth factor involved in pathophysiological processes like angiogenesis or atherosclerosis. We used primary cultured VSMC obtained from rat aorta, which express the three ERM proteins. Simultaneous depletion of the three ERM proteins with specific siRNAs abolished the effects of PDGF on cell architecture and migration and markedly increased cell adhesion and focal adhesion size, while these parameters were only slightly affected by depletion of ezrin, radixin or moesin alone. Rac1 activation, cell proliferation, and Ca{sup 2+} signal in response to PDGF were unaffected by ERM depletion. These results indicate that ERM proteins exert a redundant control on PDGF-induced VSMC migration by regulating focal adhesion turn-over and cell adhesion to substrate.

  13. Fibronectin Modulates Cell Adhesion and Signaling to Promote Single Cell Migration of Highly Invasive Oral Squamous Cell Carcinoma

    Science.gov (United States)

    Ramos, Grasieli de Oliveira; Bernardi, Lisiane; Lauxen, Isabel; Sant’Ana Filho, Manoel; Horwitz, Alan Rick; Lamers, Marcelo Lazzaron

    2016-01-01

    Cell migration is regulated by adhesion to the extracellular matrix (ECM) through integrins and activation of small RhoGTPases, such as RhoA and Rac1, resulting in changes to actomyosin organization. During invasion, epithelial-derived tumor cells switch from laminin-enriched basal membrane to collagen and fibronectin-enriched connective tissue. How this switch affects the tumor migration is still unclear. We tested the hypothesis that ECM dictates the invasiveness of Oral Squamous Cell Carcinoma (OSCC). We analyzed the migratory properties of two OSCC lines, a low invasive cell line with high e-cadherin levels (Linv/HE-cad) or a highly invasive cell line with low e-cadherin levels (Hinv/LE-cad), plated on different ECM components. Compared to laminin, fibronectin induced non-directional collective migration and decreased RhoA activity in Linv/HE-cad OSCC. For Hinv/LE-cad OSCC, fibronectin increased Rac1 activity and induced smaller adhesions, resulting in a fast single cell migration in both 2D and 3D environments. Consistent with these observations, human OSCC biopsies exhibited similar changes in cell-ECM adhesion distribution at the invasive front of the tumor, where cells encounter fibronectin. Our results indicate that ECM composition might induce a switch from collective to single cell migration according to tumor invasiveness due to changes in cell-ECM adhesion and the resulting signaling pathways that alter actomyosin organization. PMID:26978651

  14. Fibronectin Modulates Cell Adhesion and Signaling to Promote Single Cell Migration of Highly Invasive Oral Squamous Cell Carcinoma.

    Directory of Open Access Journals (Sweden)

    Grasieli de Oliveira Ramos

    Full Text Available Cell migration is regulated by adhesion to the extracellular matrix (ECM through integrins and activation of small RhoGTPases, such as RhoA and Rac1, resulting in changes to actomyosin organization. During invasion, epithelial-derived tumor cells switch from laminin-enriched basal membrane to collagen and fibronectin-enriched connective tissue. How this switch affects the tumor migration is still unclear. We tested the hypothesis that ECM dictates the invasiveness of Oral Squamous Cell Carcinoma (OSCC. We analyzed the migratory properties of two OSCC lines, a low invasive cell line with high e-cadherin levels (Linv/HE-cad or a highly invasive cell line with low e-cadherin levels (Hinv/LE-cad, plated on different ECM components. Compared to laminin, fibronectin induced non-directional collective migration and decreased RhoA activity in Linv/HE-cad OSCC. For Hinv/LE-cad OSCC, fibronectin increased Rac1 activity and induced smaller adhesions, resulting in a fast single cell migration in both 2D and 3D environments. Consistent with these observations, human OSCC biopsies exhibited similar changes in cell-ECM adhesion distribution at the invasive front of the tumor, where cells encounter fibronectin. Our results indicate that ECM composition might induce a switch from collective to single cell migration according to tumor invasiveness due to changes in cell-ECM adhesion and the resulting signaling pathways that alter actomyosin organization.

  15. Single Cell Force Spectroscopy for Quantification of Cellular Adhesion on Surfaces

    Science.gov (United States)

    Christenson, Wayne B.

    Cell adhesion is an important aspect of many biological processes. The atomic force microscope (AFM) has made it possible to quantify the forces involved in cellular adhesion using a technique called single cell force spectroscopy (SCFS). AFM based SCFS offers versatile control over experimental conditions for probing directly the interaction between specific cell types and specific proteins, surfaces, or other cells. Transmembrane integrins are the primary proteins involved in cellular adhesion to the extra cellular matix (ECM). One of the chief integrins involved in the adhesion of leukocyte cells is alpha Mbeta2 (Mac-1). The experiments in this dissertation quantify the adhesion of Mac-1 expressing human embryonic kidney (HEK Mac-1), platelets, and neutrophils cells on substrates with different concentrations of fibrinogen and on fibrin gels and multi-layered fibrinogen coated fibrin gels. It was shown that multi-layered fibrinogen reduces the adhesion force of these cells considerably. A novel method was developed as part of this research combining total internal reflection microscopy (TIRFM) with SCFS allowing for optical microscopy of HEK Mac-1 cells interacting with bovine serum albumin (BSA) coated glass after interacting with multi-layered fibrinogen. HEK Mac-1 cells are able to remove fibrinogen molecules from the multi-layered fibrinogen matrix. An analysis methodology for quantifying the kinetic parameters of integrin-ligand interactions from SCFS experiments is proposed, and the kinetic parameters of the Mac-1 fibrinogen bond are quantified. Additional SCFS experiments quantify the adhesion of macrophages and HEK Mac-1 cells on functionalized glass surfaces and normal glass surfaces. Both cell types show highest adhesion on a novel functionalized glass surface that was prepared to induce macrophage fusion. These experiments demonstrate the versatility of AFM based SCFS, and how it can be applied to address many questions in cellular biology offering

  16. A hot water extract of Curcuma longa inhibits adhesion molecule protein expression and monocyte adhesion to TNF-α-stimulated human endothelial cells.

    Science.gov (United States)

    Kawasaki, Kengo; Muroyama, Koutarou; Yamamoto, Norio; Murosaki, Shinji

    2015-01-01

    The recruitment of arterial leukocytes to endothelial cells is an important step in the progression of various inflammatory diseases. Therefore, its modulation is thought to be a prospective target for the prevention or treatment of such diseases. Adhesion molecules on endothelial cells are induced by proinflammatory cytokines, including tumor necrosis factor-α (TNF-α), and contribute to the recruitment of leukocytes. In the present study, we investigated the effect of hot water extract of Curcuma longa (WEC) on the protein expression of adhesion molecules, monocyte adhesion induced by TNF-α in human umbilical vascular endothelial cells (HUVECs). Treatment of HUVECs with WEC significantly suppressed both TNF-α-induced protein expression of adhesion molecules and monocyte adhesion. WEC also suppressed phosphorylation and degradation of nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor, alpha (IκBα) induced by TNF-α in HUVECs, suggesting that WEC inhibits the NF-κB signaling pathway.

  17. Adhesion of Two Lactobacillus gasseri Probiotic Strains on Caco-2 Cells

    Directory of Open Access Journals (Sweden)

    Mojca Narat

    2003-01-01

    Full Text Available Previous in vitro and in vivo studies showed that two human isolates of Lactobacillus gasseri, LF221 and K7 are able to survive the passage through the gastrointestinal tract and to colonise intestines of pigs at least temporarily. The aim of this study was to examine the adhesion ability of LF221 and K7 strains to Caco-2 cells. Adhesion of lactobacilli from early stationary growth phase was examined at two pH values of DMEM buffer (4.5 and 7. Lactobacillus rhamnosus GG, a widely used strain with clinical evidences of its efficiency, served as a positive control. The number of lactobacilli added to each well was found to be crucial in the adhesion assay. When added, lactobacilli were in range of 2.5 · 106 to 2.5 · 108 cfu/well, the linear correlation between the number of adhered cells (log cfu and the number of added cells (log cfu was found for all three strains (R2 > 0.99 at both pH values (4.5 and 7. At the highest concentration of added K7 and GG cells tested (app. 109 cfu/well, the efficiency of adhesion was reduced. pH value of the medium strongly affected the adhesion, which was promoted in acidic conditions (pH=4.5. The adhesion of K7 strain was slightly weaker compared to GG strain at both pH values, while at pH=4.5 the adhesion of LF221 strain was even better than GG adhesion, at least at lower concentration of lactobacilli. The direct comparison of these strains was possible by regression analysis. At lower concentration of lactobacilli (2.5 · 106, the best efficiency of adhesion (% of adhered bacteria was observed for the strain LF221, reaching the values of 7.8 and 1.9 % at pH=4.5 and 7, respectively, while at higher lactobacilli concentration the ration of adhesion was higher for GG strain (3.3 % at pH=4.5. In conclusion, strains LF221 and K7 were demonstrated to be adhesive, especially in acidic conditions. The level of adhesion of K7 and GG strains positively correlates with the number of added lactobacilli only up to the

  18. Modeling cell-substrate de-adhesion dynamics under fluid shear

    Science.gov (United States)

    Maan, Renu; Rani, Garima; Menon, Gautam I.; Pullarkat, Pramod A.

    2018-07-01

    Changes in cell-substrate adhesion are believed to signal the onset of cancer metastasis, but such changes must be quantified against background levels of intrinsic heterogeneity between cells. Variations in cell-substrate adhesion strengths can be probed through biophysical measurements of cell detachment from substrates upon the application of an external force. Here, we investigate, theoretically and experimentally, the detachment of cells adhered to substrates when these cells are subjected to fluid shear. We present a theoretical framework within which we calculate the fraction of detached cells as a function of shear stress for fast ramps as well as the decay in this fraction at fixed shear stress as a function of time. Using HEK and 3T3 fibroblast cells as experimental model systems, we extract characteristic force scales for cell adhesion as well as characteristic detachment times. We estimate force-scales of  ∼500 pN associated to a single focal contact, and characteristic time-scales of s representing cell-spread-area dependent mean first passage times to the detached state at intermediate values of the shear stress. Variations in adhesion across cell types are especially prominent when cell detachment is probed by applying a time-varying shear stress. These methods can be applied to characterizing changes in cell adhesion in a variety of contexts, including metastasis.

  19. Regulation of promyogenic signal transduction by cell-cell contact and adhesion

    International Nuclear Information System (INIS)

    Krauss, Robert S.

    2010-01-01

    Skeletal myoblast differentiation involves acquisition of the muscle-specific transcriptional program and morphological changes, including fusion into multinucleated myofibers. Differentiation is regulated by extracellular signaling cues, including cell-cell contact and adhesion. Cadherin and Ig adhesion receptors have been implicated in distinct but overlapping stages of myogenesis. N-cadherin signals through the Ig receptor Cdo to activate p38 MAP kinase, while the Ig receptor neogenin signals to activate FAK; both processes promote muscle-specific gene expression and myoblast fusion. M-cadherin activates Rac1 to enhance fusion. Specific Ig receptors (Kirre and Sns) are essential for myoblast fusion in Drosophila, also signaling through Rac, and vertebrate orthologs of Kirre and Sns have partially conserved function. Mice lacking specific cytoplasmic signaling factors activated by multiple receptors (e.g., Rac1) have strong muscle phenotypes in vivo. In contrast, mice lacking individual adhesion receptors that lie upstream of these factors have modest phenotypes. Redundancy among receptors may account for this. Many of the mammalian Ig receptors and cadherins associate with each other, and multivalent interactions within these complexes may require removal of multiple components to reveal dramatic defects in vivo. Nevertheless, it is possible that the murine adhesion receptors rate-limiting in vivo have not yet been identified or fully assessed.

  20. Regulation of promyogenic signal transduction by cell-cell contact and adhesion

    Energy Technology Data Exchange (ETDEWEB)

    Krauss, Robert S., E-mail: Robert.Krauss@mssm.edu [Department of Developmental and Regenerative Biology, Mount Sinai School of Medicine, New York, NY 10029 (United States)

    2010-11-01

    Skeletal myoblast differentiation involves acquisition of the muscle-specific transcriptional program and morphological changes, including fusion into multinucleated myofibers. Differentiation is regulated by extracellular signaling cues, including cell-cell contact and adhesion. Cadherin and Ig adhesion receptors have been implicated in distinct but overlapping stages of myogenesis. N-cadherin signals through the Ig receptor Cdo to activate p38 MAP kinase, while the Ig receptor neogenin signals to activate FAK; both processes promote muscle-specific gene expression and myoblast fusion. M-cadherin activates Rac1 to enhance fusion. Specific Ig receptors (Kirre and Sns) are essential for myoblast fusion in Drosophila, also signaling through Rac, and vertebrate orthologs of Kirre and Sns have partially conserved function. Mice lacking specific cytoplasmic signaling factors activated by multiple receptors (e.g., Rac1) have strong muscle phenotypes in vivo. In contrast, mice lacking individual adhesion receptors that lie upstream of these factors have modest phenotypes. Redundancy among receptors may account for this. Many of the mammalian Ig receptors and cadherins associate with each other, and multivalent interactions within these complexes may require removal of multiple components to reveal dramatic defects in vivo. Nevertheless, it is possible that the murine adhesion receptors rate-limiting in vivo have not yet been identified or fully assessed.

  1. Cell Adhesion Molecules Are Mediated by Photobiomodulation at 660 nm in Diabetic Wounded Fibroblast Cells

    Directory of Open Access Journals (Sweden)

    Nicolette N. Houreld

    2018-04-01

    Full Text Available Diabetes affects extracellular matrix (ECM metabolism, contributing to delayed wound healing and lower limb amputation. Application of light (photobiomodulation, PBM has been shown to improve wound healing. This study aimed to evaluate the influence of PBM on cell adhesion molecules (CAMs in diabetic wound healing. Isolated human skin fibroblasts were grouped into a diabetic wounded model. A diode laser at 660 nm with a fluence of 5 J/cm2 was used for irradiation and cells were analysed 48 h post-irradiation. Controls consisted of sham-irradiated (0 J/cm2 cells. Real-time reverse transcription (RT quantitative polymerase chain reaction (qPCR was used to determine the expression of CAM-related genes. Ten genes were up-regulated in diabetic wounded cells, while 25 genes were down-regulated. Genes were related to transmembrane molecules, cell–cell adhesion, and cell–matrix adhesion, and also included genes related to other CAM molecules. PBM at 660 nm modulated gene expression of various CAMs contributing to the increased healing seen in clinical practice. There is a need for new therapies to improve diabetic wound healing. The application of PBM alongside other clinical therapies may be very beneficial in treatment.

  2. Biodegradable copolymers carrying cell-adhesion peptide sequences.

    Science.gov (United States)

    Proks, Vladimír; Machová, Lud'ka; Popelka, Stepán; Rypácek, Frantisek

    2003-01-01

    Amphiphilic block copolymers are used to create bioactive surfaces on biodegradable polymer scaffolds for tissue engineering. Cell-selective biomaterials can be prepared using copolymers containing peptide sequences derived from extracellular-matrix proteins (ECM). Here we discuss alternative ways for preparation of amphiphilic block copolymers composed of hydrophobic polylactide (PLA) and hydrophilic poly(ethylene oxide) (PEO) blocks with cell-adhesion peptide sequences. Copolymers PLA-b-PEO were prepared by a living polymerisation of lactide in dioxane with tin(II)2-ethylhexanoate as a catalyst. The following approaches for incorporation of peptides into copolymers were elaborated. (a) First, a side-chain protected Gly-Arg-Gly-Asp-Ser-Gly (GRGDSG) peptide was prepared by solid-phase peptide synthesis (SPPS) and then coupled with delta-hydroxy-Z-amino-PEO in solution. In the second step, the PLA block was grafted to it via a controlled polymerisation of lactide initiated by the hydroxy end-groups of PEO in the side-chain-protected GRGDSG-PEO. Deprotection of the peptide yielded a GRGDSG-b-PEO-b-PLA copolymer, with the peptide attached through its C-end. (b) A protected GRGDSG peptide was built up on a polymer resin and coupled with Z-carboxy-PEO using a solid-phase approach. After cleavage of the delta-hydroxy-PEO-GRGDSG copolymer from the resin, polymerisation of lactide followed by deprotection of the peptide yielded a PLA-b-PEO-b-GRGDSG block copolymer, in which the peptide is linked through its N-terminus.

  3. Suppression of endothelial cell adhesion by XJP-1, a new phenolic compound derived from banana peel.

    Science.gov (United States)

    Fu, Rong; Yan, Tianhua; Wang, Qiujuan; Guo, Qinglong; Yao, Hequan; Wu, Xiaoming; Li, Yang

    2012-01-01

    The adhesion of monocytes to activated vascular endothelial cells is a critical event in the initiation of atherosclerosis. Adhesion is mediated by oxidized low-density lipoprotein (ox-LDL) which up-regulates inflammatory markers on endothelial cells. Here we report that (±) 7, 8-dihydroxy-3-methyl-isochromanone-4 (XJP-1), an inhibitor of ox-LDL-induced adhesion of monocytes to endothelial cells blocks cellular functions which are associated with adhesion. We show that XJP-1 down-regulates ox-LDL-induced over-expression of adhesion molecules (ICAM-1 and VCAM-1) in a dose-dependent manner in human umbilical vein endothelial cells (HUVECs), attenuates ox-LDL-induced up-regulation of low-density lipoprotein receptor (LOX)-1, decreases generation of reactive oxygen species (ROS), blocks translocation of nuclear factor-kappa B (NF-κB) activity, and prevents activation of c-Jun N-terminal kinase (JNK)/p38 pathways in endothelial cells. These findings suggest that XJP-1 may attenuate ox-LDL-induced endothelial adhesion of monocytes by blocking expression of adhesion molecules through suppressing ROS/NF-κB, JNK and p38 pathways. Copyright © 2012 Elsevier Inc. All rights reserved.

  4. Interlayer adhesion in roll-to-roll processed flexible inverted polymer solar cells

    KAUST Repository

    Dupont, Stephanie R.

    2012-02-01

    The interlayer adhesion of roll-to-roll processed flexible inverted P3HT:PCBM bulk heterojunction (BHJ) polymer solar cells is reported. Poor adhesion between adjacent layers may result in loss of device performance from delamination driven by the thermomechanical stresses in the device. We demonstrate how a thin-film adhesion technique can be applied to flexible organic solar cells to obtain quantitative adhesion values. For the P3HT:PCBM-based BHJ polymer solar cells, the interface of the BHJ with the conductive polymer layer PEDOT:PSS was found to be the weakest. The adhesion fracture energy varied from 1.6 J/m2 to 0.1 J/m2 depending on the composition of the P3HT:PCBM layer. Post-deposition annealing time and temperature were shown to increase the adhesion at this interface. Additionally the PEDOT:PSS cells are compared with V2O5 cells whereby adhesive failure marked by high fracture energies was observed. © 2011 Elsevier B.V.

  5. Membrane tension controls adhesion positioning at the leading edge of cells.

    Science.gov (United States)

    Pontes, Bruno; Monzo, Pascale; Gole, Laurent; Le Roux, Anabel-Lise; Kosmalska, Anita Joanna; Tam, Zhi Yang; Luo, Weiwei; Kan, Sophie; Viasnoff, Virgile; Roca-Cusachs, Pere; Tucker-Kellogg, Lisa; Gauthier, Nils C

    2017-09-04

    Cell migration is dependent on adhesion dynamics and actin cytoskeleton remodeling at the leading edge. These events may be physically constrained by the plasma membrane. Here, we show that the mechanical signal produced by an increase in plasma membrane tension triggers the positioning of new rows of adhesions at the leading edge. During protrusion, as membrane tension increases, velocity slows, and the lamellipodium buckles upward in a myosin II-independent manner. The buckling occurs between the front of the lamellipodium, where nascent adhesions are positioned in rows, and the base of the lamellipodium, where a vinculin-dependent clutch couples actin to previously positioned adhesions. As membrane tension decreases, protrusion resumes and buckling disappears, until the next cycle. We propose that the mechanical signal of membrane tension exerts upstream control in mechanotransduction by periodically compressing and relaxing the lamellipodium, leading to the positioning of adhesions at the leading edge of cells. © 2017 Pontes et al.

  6. Differential and Cooperative Cell Adhesion Regulates Cellular Pattern in Sensory Epithelia.

    Science.gov (United States)

    Togashi, Hideru

    2016-01-01

    Animal tissues are composed of multiple cell types arranged in complex and elaborate patterns. In sensory epithelia, including the auditory epithelium and olfactory epithelium, different types of cells are arranged in unique mosaic patterns. These mosaic patterns are evolutionarily conserved, and are thought to be important for hearing and olfaction. Recent progress has provided accumulating evidence that the cellular pattern formation in epithelia involves cell rearrangements, movements, and shape changes. These morphogenetic processes are largely mediated by intercellular adhesion systems. Differential adhesion and cortical tension have been proposed to promote cell rearrangements. Many different types of cells in tissues express various types of cell adhesion molecules. Although cooperative mechanisms between multiple adhesive systems are likely to contribute to the production of complex cell patterns, our current understanding of the cooperative roles between multiple adhesion systems is insufficient to entirely explain the complex mechanisms underlying cellular patterning. Recent studies have revealed that nectins, in cooperation with cadherins, are crucial for the mosaic cellular patterning in sensory organs. The nectin and cadherin systems are interacted with one another, and these interactions provide cells with differential adhesive affinities for complex cellular pattern formations in sensory epithelia, which cannot be achieved by a single mechanism.

  7. Cellular Adhesion and Adhesion Molecules

    OpenAIRE

    SELLER, Zerrin

    2014-01-01

    In recent years, cell adhesion and cell adhesion molecules have been shown to be important for many normal biological processes, including embryonic cell migration, immune system functions and wound healing. It has also been shown that they contribute to the pathogenesis of a large number of common human disorders, such as rheumatoid arthritis and tumor cell metastasis in cancer. In this review, the basic mechanisms of cellular adhesion and the structural and functional features of adhes...

  8. The Role of TSC Proteins in Regulating Cell Adhesion and Motility

    National Research Council Canada - National Science Library

    Krymskaya, Vera P

    2006-01-01

    The goal of this project was to define the molecular signaling mechanisms by which TSCI and TSC2 proteins regulate cell adhesion and motility as it relates to the genetic disorder tuberous sclerosis complex (TSC...

  9. Combined modeling of cell aggregation and adhesion mediated by receptor–ligand interactions under shear flow

    Directory of Open Access Journals (Sweden)

    Yu Du

    2015-11-01

    Full Text Available Blood cell aggregation and adhesion to endothelial cells under shear flow are crucial to many biological processes such as thrombi formation, inflammatory cascade, and tumor metastasis, in which these cellular interactions are mainly mediated by the underlying receptor–ligand bindings. While theoretical modeling of aggregation dynamics and adhesion kinetics of interacting cells have been well studied separately, how to couple these two processes remains unclear. Here we develop a combined model that couples cellular aggregation dynamics and adhesion kinetics under shear flow. The impacts of shear rate (or shear stress and molecular binding affinity were elucidated. This study provides a unified model where the action of a fluid flow drives cell aggregation and adhesion under the modulations of the mechanical shear flow and receptor–ligand interaction kinetics. It offers an insight into understanding the relevant biological processes and functions.

  10. The effect of magnesium ion implantation into alumina upon the adhesion of human bone derived cells

    International Nuclear Information System (INIS)

    Howlett, C.R.; Zreiqat, H.; O'Dell, R.; Noorman, J.; Evans, P.; Dalton, B.A.; McFarland, C.; Steele, J.G.

    1994-01-01

    Our group is investigating the potential of modifying the surface atomic layers of biomaterials by ion beam implantation in order to stimulate adhesion of bone cells to these treated biomaterials. In this study alumina that had been implanted with magnesium ions (Mg)-(Al 2 O 3 ), was compared to unmodified alumina (Al 2 O 3 ) for the adhesion of cells cultured from explanted human bone. The attachment and spreading of cultured human bone derived cells onto (Mg)-(Al 2 O 3 ) was significantly enhanced as compared to Al 2 O 3 . The role of adsorption of serum adhesive glycoproteins firbronectin (Fn) and vitronectin (Vn) in the adhesion of human bone derived cells to (Mg)-(Al 2 O 3 ) was determined. (Author)

  11. Epigenetic Silencing of CXCR4 Promotes Loss of Cell Adhesion in Cervical Cancer

    Directory of Open Access Journals (Sweden)

    Suresh Singh Yadav

    2014-01-01

    Full Text Available In the network of chemokine signaling pathways, recent reports have described the SDF-1α/CXCR4 axis and its role in cancer progression and metastasis. Interestingly, we found downregulation of CXCR4 at both transcript and protein level in cervical cancer cell lines and primary tumors. We also found CXCR4 promoter hypermethylation in cervical cancer cell lines and primary biopsy samples. DNA hypomethylating drug 5-AZA-2′-deoxycytidine and histone deacetylase inhibitor Trichostatin A treatments in cell lines reactivate both CXCR4 transcription and protein expression. Cell adhesion assay demonstrated that autocrine SDF-1α promotes the loss of cell adhesion while paracrine SDF-1α predominantly protects the normal cervical cells from loss of cell adhesion. Cervical cancer cell line C-33A having increased expression of CXCR4 after TSA treatment showed increased cell adhesion by paracrine source of SDF-1α in comparison to untreated C-33A. These findings demonstrate the first evidence that epigenetic silencing of CXCR4 makes the cells inefficient to respond to the paracrine source of SDF-1α leading to loss of cell adhesion, one of the key events in metastases and progression of the disease. Our results provide novel insight of SDF-1α/CXCR4 signaling in tumor microenvironment which may be promising to further delineate molecular mechanism of cervical carcinogenesis.

  12. Micro–adhesion rings surrounding TCR microclusters are essential for T cell activation

    Science.gov (United States)

    Sakuma, Machie; Yokosuka, Tadashi

    2016-01-01

    The immunological synapse (IS) formed at the interface between T cells and antigen-presenting cells represents a hallmark of initiation of acquired immunity. T cell activation is initiated at T cell receptor (TCR) microclusters (MCs), in which TCRs and signaling molecules assemble at the interface before IS formation. We found that each TCR-MC was transiently bordered by a ring structure made of integrin and focal adhesion molecules in the early phase of activation, which is similar in structure to the IS in microscale. The micro–adhesion ring is composed of LFA-1, focal adhesion molecules paxillin and Pyk2, and myosin II (MyoII) and is supported by F-actin core and MyoII activity through LFA-1 outside-in signals. The formation of the micro–adhesion ring was transient but especially sustained upon weak TCR stimulation to recruit linker for activation of T cells (LAT) and SLP76. Perturbation of the micro–adhesion ring induced impairment of TCR-MC development and resulted in impaired cellular signaling and cell functions. Thus, the synapse-like structure composed of the core TCR-MC and surrounding micro–adhesion ring is a critical structure for initial T cell activation through integrin outside-in signals. PMID:27354546

  13. Effects of adhesion dynamics and substrate compliance on the shape and motility of crawling cells.

    Directory of Open Access Journals (Sweden)

    Falko Ziebert

    Full Text Available Computational modeling of eukaryotic cells moving on substrates is an extraordinarily complex task: many physical processes, such as actin polymerization, action of motors, formation of adhesive contacts concomitant with both substrate deformation and recruitment of actin etc., as well as regulatory pathways are intertwined. Moreover, highly nontrivial cell responses emerge when the substrate becomes deformable and/or heterogeneous. Here we extended a computational model for motile cell fragments, based on an earlier developed phase field approach, to account for explicit dynamics of adhesion site formation, as well as for substrate compliance via an effective elastic spring. Our model displays steady motion vs. stick-slip transitions with concomitant shape oscillations as a function of the actin protrusion rate, the substrate stiffness, and the rates of adhesion. Implementing a step in the substrate's elastic modulus, as well as periodic patterned surfaces exemplified by alternating stripes of high and low adhesiveness, we were able to reproduce the correct motility modes and shape phenomenology found experimentally. We also predict the following nontrivial behavior: the direction of motion of cells can switch from parallel to perpendicular to the stripes as a function of both the adhesion strength and the width ratio of adhesive to non-adhesive stripes.

  14. Local 3D matrix microenvironment regulates cell migration through spatiotemporal dynamics of contractility-dependent adhesions

    Science.gov (United States)

    Doyle, Andrew D.; Carvajal, Nicole; Jin, Albert; Matsumoto, Kazue; Yamada, Kenneth M.

    2015-11-01

    The physical properties of two-dimensional (2D) extracellular matrices (ECMs) modulate cell adhesion dynamics and motility, but little is known about the roles of local microenvironmental differences in three-dimensional (3D) ECMs. Here we generate 3D collagen gels of varying matrix microarchitectures to characterize their regulation of 3D adhesion dynamics and cell migration. ECMs containing bundled fibrils demonstrate enhanced local adhesion-scale stiffness and increased adhesion stability through balanced ECM/adhesion coupling, whereas highly pliable reticular matrices promote adhesion retraction. 3D adhesion dynamics are locally regulated by ECM rigidity together with integrin/ECM association and myosin II contractility. Unlike 2D migration, abrogating contractility stalls 3D migration regardless of ECM pore size. We find force is not required for clustering of activated integrins on 3D native collagen fibrils. We propose that efficient 3D migration requires local balancing of contractility with ECM stiffness to stabilize adhesions, which facilitates the detachment of activated integrins from ECM fibrils.

  15. Nanofibers and nanoparticles from the insect-capturing adhesive of the Sundew (Drosera for cell attachment

    Directory of Open Access Journals (Sweden)

    Zhang Mingjun

    2010-08-01

    Full Text Available Abstract Background The search for naturally occurring nanocomposites with diverse properties for tissue engineering has been a major interest for biomaterial research. In this study, we investigated a nanofiber and nanoparticle based nanocomposite secreted from an insect-capturing plant, the Sundew, for cell attachment. The adhesive nanocomposite has demonstrated high biocompatibility and is ready to be used with minimal preparation. Results Atomic force microscopy (AFM conducted on the adhesive from three species of Sundew found that a network of nanofibers and nanoparticles with various sizes existed independent of the coated surface. AFM and light microscopy confirmed that the pattern of nanofibers corresponded to Alcian Blue staining for polysaccharide. Transmission electron microscopy identified a low abundance of nanoparticles in different pattern form AFM observations. In addition, energy-dispersive X-ray spectroscopy revealed the presence of Ca, Mg, and Cl, common components of biological salts. Study of the material properties of the adhesive yielded high viscoelasticity from the liquid adhesive, with reduced elasticity observed in the dried adhesive. The ability of PC12 neuron-like cells to attach and grow on the network of nanofibers created from the dried adhesive demonstrated the potential of this network to be used in tissue engineering, and other biomedical applications. Conclusions This discovery demonstrates how a naturally occurring nanofiber and nanoparticle based nanocomposite from the adhesive of Sundew can be used for tissue engineering, and opens the possibility for further examination of natural plant adhesives for biomedical applications.

  16. Multinuclear giant cell formation is enhanced by down-regulation of Wnt signaling in gastric cancer cell line, AGS

    International Nuclear Information System (INIS)

    Kim, Shi-Mun; Kim, Rockki; Ryu, Jae-Hyun; Jho, Eek-Hoon; Song, Ki-Joon; Jang, Shyh-Ing; Kee, Sun-Ho

    2005-01-01

    AGS cells, which were derived from malignant gastric adenocarcinoma tissue, lack E-cadherin-mediated cell adhesion but have a high level of nuclear β-catenin, which suggests altered Wnt signal. In addition, approximately 5% of AGS cells form multinuclear giant cells in the routine culture conditions, while taxol treatment causes most AGS cells to become giant cells. The observation of reduced nuclear β-catenin levels in giant cells induced by taxol treatment prompted us to investigate the relationship between Wnt signaling and giant cell formation. After overnight serum starvation, the shape of AGS cells became flattened, and this morphological change was accompanied by decrease in Myc expression and an increase in the giant cell population. Lithium chloride treatment, which inhibits GSK3β activity, reversed these serum starvation effects, which suggests an inverse relationship between Wnt signaling and giant cell formation. Furthermore, the down-regulation of Wnt signaling caused by the over-expression of ICAT, E-cadherin, and Axin enhanced giant cell formation. Therefore, down-regulation of Wnt signaling may be related to giant cell formation, which is considered to be a survival mechanism against induced cell death

  17. Cell adhesion on Ti surface with controlled roughness

    Directory of Open Access Journals (Sweden)

    Burgos-Asperilla, Laura

    2015-06-01

    Full Text Available In this report, the in situ interaction between Saos-2 osteoblast cells and a smooth Ti surface was examined over time. The adhesion kinetics and mechanisms of cellular proliferation were monitored by quartz crystal microbalance (QCM and electrochemical impedance spectroscopy (EIS. The rate of Saos-2 attachment on Ti surfaces, obtained from the measurements performed with the QCM, is a first-order reaction, with k=2.10−3 min−1. The impedance measurements indicate that in the absence of cells, the Ti resistance diminishes over time (7 days, due to the presence of amino acids and proteins from the culture medium that have been a dsorbed, while in the presence of osteoblasts, this decrease is much greater because of the compounds generated by the cells that accelerate the dissolution of Ti.En este trabajo, se ha estudiado la interacción in situ entre células osteoblásticas Saos-2 y una superficie de Ti de rugosidad controlada a lo largo del tiempo. El estudio de la cinética y los mecanismos de proliferación celular de adhesión se ha realizado a través de la microbalanza de cristal de cuarzo (QCM y espectroscopía de impedancia electroquímica (EIS. La velocidad de adhesión de los osteoblastos sobre la superficie de Ti obtenida a través de medidas con la QCM, sigue una reacción de primer orden, con k=2×10−3 min−1. Los ensayos de impedancia indican que, en ausencia de las células, la resistencia del Ti disminuye con el tiempo (7 días, debido a la presencia de aminoácidos y proteínas del medio de cultivo que se han adsorbido, mientras que en presencia de células, esta disminución es mucho mayor debido a los productos metabólicos generados por las células que aceleran la disolución del Ti.

  18. Adhesion to the host cell surface is sufficient to mediate Listeria monocytogenes entry into epithelial cells

    Science.gov (United States)

    Ortega, Fabian E.; Rengarajan, Michelle; Chavez, Natalie; Radhakrishnan, Prathima; Gloerich, Martijn; Bianchini, Julie; Siemers, Kathleen; Luckett, William S.; Lauer, Peter; Nelson, W. James; Theriot, Julie A.

    2017-01-01

    The intestinal epithelium is the first physiological barrier breached by the Gram-positive facultative pathogen Listeria monocytogenes during an in vivo infection. Listeria monocytogenes binds to the epithelial host cell receptor E-cadherin, which mediates a physical link between the bacterium and filamentous actin (F-actin). However, the importance of anchoring the bacterium to F-actin through E-cadherin for bacterial invasion has not been tested directly in epithelial cells. Here we demonstrate that depleting αE-catenin, which indirectly links E-cadherin to F-actin, did not decrease L. monocytogenes invasion of epithelial cells in tissue culture. Instead, invasion increased due to increased bacterial adhesion to epithelial monolayers with compromised cell–cell junctions. Furthermore, expression of a mutant E-cadherin lacking the intracellular domain was sufficient for efficient L. monocytogenes invasion of epithelial cells. Importantly, direct biotin-mediated binding of bacteria to surface lipids in the plasma membrane of host epithelial cells was sufficient for uptake. Our results indicate that the only requirement for L. monocytogenes invasion of epithelial cells is adhesion to the host cell surface, and that E-cadherin–mediated coupling of the bacterium to F-actin is not required. PMID:28877987

  19. Laser Phototherapy Enhances Mesenchymal Stem Cells Survival in Response to the Dental Adhesives

    Directory of Open Access Journals (Sweden)

    Ivana Márcia Alves Diniz

    2015-01-01

    Full Text Available Background. We investigated the influence of laser phototherapy (LPT on the survival of human mesenchymal stem cells (MSCs submitted to substances leached from dental adhesives. Method. MSCs were isolated and characterized. Oral mucosa fibroblasts and osteoblast-like cells were used as comparative controls. Cultured medium conditioned with two adhesive systems was applied to the cultures. Cell monolayers were exposed or not to LPT. Laser irradiations were performed using a red laser (GaAlAs, 780 nm, 0.04 cm2, 40 mW, 1 W/cm2, 0.4 J, 10 seconds, 1 point, 10 J/cm2. After 24 h, cell viability was assessed by the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide reduction assay. Data were statistically compared by ANOVA followed by Tukey’s test (P<0.05. Results. Different cell types showed different viabilities in response to the same materials. Substances leached from adhesives were less cytotoxic to MSCs than to other cell types. Substances leached from Clearfil SE Bond were highly cytotoxic to all cell types tested, except to the MSCs when applied polymerized and in association with LPT. LPT was unable to significantly increase the cell viability of fibroblasts and osteoblast-like cells submitted to the dental adhesives. Conclusion. LPT enhances mesenchymal stem cells survival in response to substances leached from dental adhesives.

  20. Rapid and serial quantification of adhesion forces of yeast and Mammalian cells.

    Directory of Open Access Journals (Sweden)

    Eva Potthoff

    Full Text Available Cell adhesion to surfaces represents the basis for niche colonization and survival. Here we establish serial quantification of adhesion forces of different cell types using a single probe. The pace of single-cell force-spectroscopy was accelerated to up to 200 yeast and 20 mammalian cells per probe when replacing the conventional cell trapping cantilever chemistry of atomic force microscopy by underpressure immobilization with fluidic force microscopy (FluidFM. In consequence, statistically relevant data could be recorded in a rapid manner, the spectrum of examinable cells was enlarged, and the cell physiology preserved until approached for force spectroscopy. Adhesion forces of Candida albicans increased from below 4 up to 16 nN at 37°C on hydrophobic surfaces, whereas a Δhgc1-mutant showed forces consistently below 4 nN. Monitoring adhesion of mammalian cells revealed mean adhesion forces of 600 nN of HeLa cells on fibronectin and were one order of magnitude higher than those observed for HEK cells.

  1. Study of the adhesion interaction using 51Cr labelling method between the myeloma cell lines and the endothelial cells

    International Nuclear Information System (INIS)

    Zhang Xueguang; Wang Jiangfang; Mao Zijun

    1995-06-01

    Using 51 Cr labelled multiple myeloma (MM) cell lines U266/XG-7, the regulatory effect of cytokines on the adhesive interaction between myeloma-cell lines U266/XG-7 and the endothelial cells, and the effects of these cytokines on expression of adhesion molecules and secretion of other cytokines were studied. The experimental results were as follows: (1) IL-6 and IL-6 Rgp 130-associated growth factors (such as GM-CSF) are not only myeloma cell growth factors, but also can enhance the adhesion between MM cells and endothelial cells and thus facilitated the metastasis of tumor cells. (2) Cytokines could induce increase in the expression of CD54 and CD44 on the endothelial cells and the secretion of IL-6 and TNF by the endothelial cells. On the other hand, the adhesion could also cause the change of CD11a, CD54, CD44 and VLA-4 on surface of myeloma cells XG-7. Finally, the interaction between MM cells and stromal cells from murine bone marrow could rapidly induce autocrine of IL-6 in human IL-6-dependent MM cells. (3) The interaction between stromal cells and tumor cells regulated by the cytokines and adhesion molecules was a key element in the pathogenesis and development of human MM. Among these factors, VLA-4 might be one of the molecules involved in U266/XG-7-EC interaction. (5 tabs., 8 figs.)

  2. Impact of cell adhesion and migration on nanoparticle uptake and cellular toxicity.

    Science.gov (United States)

    Pitchaimani, Arunkumar; Nguyen, Tuyen Duong Thanh; Koirala, Mukund; Zhang, Yuntao; Aryal, Santosh

    2017-09-01

    In vitro cell-nanoparticle (NP) studies involve exposure of NPs onto the monolayer cells growing at the bottom of a culture plate, and assumed that the NPs evenly distributed for a dose-responsive effect. However, only a few proportion of the administered dose reaches the cells depending on their size, shape, surface, and density. Often the amount incubated (administered dose) is misled as a responsive dose. Herein, we proposed a cell adhesion-migration (CAM) strategy, where cells incubated with the NP coated cell culture substrate to maximize the cell-NP interaction and investigated the physiological properties of the cells. In the present study, cell adhesion and migration pattern of human breast cancer cell (MCF-7) and mouse melanoma cell (B16-F10) on cell culture substrate decorated with toxic (cetyltrimethylammonium bromide, CTAB) and biocompatible (poly (sodium 4-styrenesulphonate), PSS) gold nanoparticles (AuNPs) of different sizes (5 and 40nm) were investigated and evaluated for cellular uptake efficiency, proliferation, and toxicity. Results showed enhanced cell adhesion, migration, and nanoparticle uptake only on biocompatible PSS coated AuNP, irrespective of its size. Whereas, cytotoxic NP shows retard proliferation with reduced cellular uptake efficiency. Considering the importance of cell adhesion and migration on cellular uptake and cytotoxicity assessment of nanoparticle, CAM strategy would hold great promises in cell-NP interaction studies. Copyright © 2017. Published by Elsevier Ltd.

  3. A role for adhesion molecules in contact-dependent T help for B cells

    DEFF Research Database (Denmark)

    Owens, T

    1991-01-01

    The role of cell contact in T-dependent B cell activation was examined. Small resting B cells from C57BL/6 mice were cultured with CBA-derived, non-alloreactive cloned T helper cells in anti-T cell receptor V beta 8-coated microwells. This induced polyclonal B cell activation to enter cell cycle...... that continued cell contact involving adhesion/accessory molecules induces B cells to proliferate and to respond to T cell lymphokines. A signaling role for cell interaction molecules on B cells is proposed, similar to the role of these and analogous molecules on T cells....

  4. Engineered matrix coatings to modulate the adhesion of CD133+ human hematopoietic progenitor cells.

    Science.gov (United States)

    Franke, Katja; Pompe, Tilo; Bornhäuser, Martin; Werner, Carsten

    2007-02-01

    Interactions of hematopoietic progenitor cells (HPC) with their local microenvironments in the bone marrow are thought to control homing, differentiation, and self-renewal of the cells. To dissect the role of extracellular matrix (ECM) components of the niche microenvironment, a set of well-defined ECM coatings including fibronectin, heparin, heparan sulphate, hyaluronic acid, tropocollagen I, and co-fibrils of collagen I with heparin or hyaluronic acid was prepared and analysed with respect to the attachment of human CD133+ HPC in vitro. The extension of the adhesion areas of individual cells as well as the fraction of adherent cells were assessed by reflection interference contrast microscopy (RICM). Intense cell-matrix interactions were found on surfaces coated with fibronectin, heparin, heparan sulphate, and on the collagen I based co-fibrils. Insignificant adhesion was found for tropocollagen I and hyaluronic acid. The strongest adhesion of HPC was observed on fibronectin with contact areas of about 7 microm(2). Interaction of HPC with coatings consisting of heparin, heparan sulphate, and co-fibrils result in small circular shaped contact zones of 3 microm(2) pointing to another, less efficient, adhesion mechanism. Analysing the specificity of cell-matrix interaction by antibody blocking experiments suggests an integrin(alpha(5)beta(1))-specific adhesion on fibronectin, while adhesion on heparin was shown to be mediated by selectins (CD62L). Taken together, our data provide a basis for the design of advanced culture carriers supporting site-specific proliferation or differentiation of HPC.

  5. Glycocalyx Degradation Induces a Proinflammatory Phenotype and Increased Leukocyte Adhesion in Cultured Endothelial Cells under Flow.

    Directory of Open Access Journals (Sweden)

    Karli K McDonald

    Full Text Available Leukocyte adhesion to the endothelium is an early step in the pathogenesis of atherosclerosis. Effective adhesion requires the binding of leukocytes to their cognate receptors on the surface of endothelial cells. The glycocalyx covers the surface of endothelial cells and is important in the mechanotransduction of shear stress. This study aimed to identify the molecular mechanisms underlying the role of the glycocalyx in leukocyte adhesion under flow. We performed experiments using 3-D cell culture models, exposing human abdominal aortic endothelial cells to steady laminar shear stress (10 dynes/cm2 for 24 hours. We found that with the enzymatic degradation of the glycocalyx, endothelial cells developed a proinflammatory phenotype when exposed to uniform steady shear stress leading to an increase in leukocyte adhesion. Our results show an up-regulation of ICAM-1 with degradation compared to non-degraded controls (3-fold increase, p<0.05 and we attribute this effect to a de-regulation in NF-κB activity in response to flow. These results suggest that the glycocalyx is not solely a physical barrier to adhesion but rather plays an important role in governing the phenotype of endothelial cells, a key determinant in leukocyte adhesion. We provide evidence for how the destabilization of this structure may be an early and defining feature in the initiation of atherosclerosis.

  6. Effects of SOX2 on Proliferation, Migration and Adhesion of Human Dental Pulp Stem Cells.

    Directory of Open Access Journals (Sweden)

    Pengfei Liu

    Full Text Available As a key factor for cell pluripotent and self-renewing phenotypes, SOX2 has attracted scientists' attention gradually in recent years. However, its exact effects in dental pulp stem cells (DPSCs are still unclear. In this study, we mainly investigated whether SOX2 could affect some biological functions of DPSCs. DPSCs were isolated from the dental pulp of human impacted third molar. SOX2 overexpressing DPSCs (DPSCs-SOX2 were established through retroviral infection. The effect of SOX2 on cell proliferation, migration and adhesion ability was evaluated with CCK-8, trans-well system and fibronectin-induced cell attachment experiment respectively. Whole genome expression of DPSCs-SOX2 was analyzed with RNA microarray. Furthermore, a rescue experiment was performed with SOX2-siRNA in DPSC-SOX2 to confirm the effect of SOX2 overexpression in DPSCs. We found that SOX2 overexpression could result in the enhancement of cell proliferation, migration, and adhesion in DPSCs obviously. RNA microarray analysis indicated that some key genes in the signal pathways associated with cell cycle, migration and adhesion were upregulated in different degree, and the results were further confirmed with qPCR and western-blot. Finally, DPSC-SOX2 transfected with SOX2-siRNA showed a decrease of cell proliferation, migration and adhesion ability, which further confirmed the biological effect of SOX2 in human DPSCs. This study indicated that SOX2 could improve the cell proliferation, migration and adhesion ability of DPSCs through regulating gene expression about cell cycle, migration and adhesion, and provided a novel strategy to develop seed cells with strong proliferation, migration and adhesion ability for tissue engineering.

  7. Effects of SOX2 on Proliferation, Migration and Adhesion of Human Dental Pulp Stem Cells.

    Science.gov (United States)

    Liu, Pengfei; Cai, Jinglei; Dong, Delu; Chen, Yaoyu; Liu, Xiaobo; Wang, Yi; Zhou, Yulai

    2015-01-01

    As a key factor for cell pluripotent and self-renewing phenotypes, SOX2 has attracted scientists' attention gradually in recent years. However, its exact effects in dental pulp stem cells (DPSCs) are still unclear. In this study, we mainly investigated whether SOX2 could affect some biological functions of DPSCs. DPSCs were isolated from the dental pulp of human impacted third molar. SOX2 overexpressing DPSCs (DPSCs-SOX2) were established through retroviral infection. The effect of SOX2 on cell proliferation, migration and adhesion ability was evaluated with CCK-8, trans-well system and fibronectin-induced cell attachment experiment respectively. Whole genome expression of DPSCs-SOX2 was analyzed with RNA microarray. Furthermore, a rescue experiment was performed with SOX2-siRNA in DPSC-SOX2 to confirm the effect of SOX2 overexpression in DPSCs. We found that SOX2 overexpression could result in the enhancement of cell proliferation, migration, and adhesion in DPSCs obviously. RNA microarray analysis indicated that some key genes in the signal pathways associated with cell cycle, migration and adhesion were upregulated in different degree, and the results were further confirmed with qPCR and western-blot. Finally, DPSC-SOX2 transfected with SOX2-siRNA showed a decrease of cell proliferation, migration and adhesion ability, which further confirmed the biological effect of SOX2 in human DPSCs. This study indicated that SOX2 could improve the cell proliferation, migration and adhesion ability of DPSCs through regulating gene expression about cell cycle, migration and adhesion, and provided a novel strategy to develop seed cells with strong proliferation, migration and adhesion ability for tissue engineering.

  8. Nanomechanical measurement of adhesion and migration of leukemia cells with phorbol 12-myristate 13-acetate treatment.

    Science.gov (United States)

    Zhou, Zhuo Long; Ma, Jing; Tong, Ming-Hui; Chan, Barbara Pui; Wong, Alice Sze Tsai; Ngan, Alfonso Hing Wan

    The adhesion and traction behavior of leukemia cells in their microenvironment is directly linked to their migration, which is a prime issue affecting the release of cancer cells from the bone marrow and hence metastasis. In assessing the effectiveness of phorbol 12-myristate 13-acetate (PMA) treatment, the conventional batch-cell transwell-migration assay may not indicate the intrinsic effect of the treatment on migration, since the treatment may also affect other cellular behavior, such as proliferation or death. In this study, the pN-level adhesion and traction forces between single leukemia cells and their microenvironment were directly measured using optical tweezers and traction-force microscopy. The effects of PMA on K562 and THP1 leukemia cells were studied, and the results showed that PMA treatment significantly increased cell adhesion with extracellular matrix proteins, bone marrow stromal cells, and human fibroblasts. PMA treatment also significantly increased the traction of THP1 cells on bovine serum albumin proteins, although the effect on K562 cells was insignificant. Western blots showed an increased expression of E-cadherin and vimentin proteins after the leukemia cells were treated with PMA. The study suggests that PMA upregulates adhesion and thus suppresses the migration of both K562 and THP1 cells in their microenvironment. The ability of optical tweezers and traction-force microscopy to measure directly pN-level cell-protein or cell-cell contact was also demonstrated.

  9. Intracellular targeting of annexin A2 inhibits tumor cell adhesion, migration, and in vivo grafting.

    Science.gov (United States)

    Staquicini, Daniela I; Rangel, Roberto; Guzman-Rojas, Liliana; Staquicini, Fernanda I; Dobroff, Andrey S; Tarleton, Christy A; Ozbun, Michelle A; Kolonin, Mikhail G; Gelovani, Juri G; Marchiò, Serena; Sidman, Richard L; Hajjar, Katherine A; Arap, Wadih; Pasqualini, Renata

    2017-06-26

    Cytoskeletal-associated proteins play an active role in coordinating the adhesion and migration machinery in cancer progression. To identify functional protein networks and potential inhibitors, we screened an internalizing phage (iPhage) display library in tumor cells, and selected LGRFYAASG as a cytosol-targeting peptide. By affinity purification and mass spectrometry, intracellular annexin A2 was identified as the corresponding binding protein. Consistently, annexin A2 and a cell-internalizing, penetratin-fused version of the selected peptide (LGRFYAASG-pen) co-localized and specifically accumulated in the cytoplasm at the cell edges and cell-cell contacts. Functionally, tumor cells incubated with LGRFYAASG-pen showed disruption of filamentous actin, focal adhesions and caveolae-mediated membrane trafficking, resulting in impaired cell adhesion and migration in vitro. These effects were paralleled by a decrease in the phosphorylation of both focal adhesion kinase (Fak) and protein kinase B (Akt). Likewise, tumor cells pretreated with LGRFYAASG-pen exhibited an impaired capacity to colonize the lungs in vivo in several mouse models. Together, our findings demonstrate an unrecognized functional link between intracellular annexin A2 and tumor cell adhesion, migration and in vivo grafting. Moreover, this work uncovers a new peptide motif that binds to and inhibits intracellular annexin A2 as a candidate therapeutic lead for potential translation into clinical applications.

  10. Shape and Dynamics of Adhesive Cells: Mechanical Response of Open Systems

    Science.gov (United States)

    Yang, Yuehua; Jiang, Hongyuan

    2017-05-01

    Cell adhesion is an essential biological process. However, previous theoretical and experimental studies ignore a key variable, the changes of cellular volume and pressure, during the dynamic adhesion process. Here, we treat cells as open systems and propose a theoretical framework to investigate how the exchange of water and ions with the environment affects the shape and dynamics of cells adhered between two adhesive surfaces. We show that adherent cells can be either stable (convex or concave) or unstable (spontaneous rupture or collapse) depending on the adhesion energy density, the cell size, the separation of two adhesive surfaces, and the stiffness of the flexible surface. Strikingly, we find that the unstable states vanish when cellular volume and pressure are constant. We further show that the detachments of convex and concave cells are very different. The mechanical response of adherent cells is mainly determined by the competition between the loading rate and the regulation of the cellular volume and pressure. Finally, we show that as an open system the detachment of adherent cells is also significantly influenced by the loading history. Thus, our findings reveal a major difference between living cells and nonliving materials.

  11. Investigation of adhesion and mechanical properties of human glioma cells by single cell force spectroscopy and atomic force microscopy.

    Science.gov (United States)

    Andolfi, Laura; Bourkoula, Eugenia; Migliorini, Elisa; Palma, Anita; Pucer, Anja; Skrap, Miran; Scoles, Giacinto; Beltrami, Antonio Paolo; Cesselli, Daniela; Lazzarino, Marco

    2014-01-01

    Active cell migration and invasion is a peculiar feature of glioma that makes this tumor able to rapidly infiltrate into the surrounding brain tissue. In our recent work, we identified a novel class of glioma-associated-stem cells (defined as GASC for high-grade glioma--HG--and Gasc for low-grade glioma--LG) that, although not tumorigenic, act supporting the biological aggressiveness of glioma-initiating stem cells (defined as GSC for HG and Gsc for LG) favoring also their motility. Migrating cancer cells undergo considerable molecular and cellular changes by remodeling their cytoskeleton and cell interactions with surrounding environment. To get a better understanding about the role of the glioma-associated-stem cells in tumor progression, cell deformability and interactions between glioma-initiating stem cells and glioma-associated-stem cells were investigated. Adhesion of HG/LG-cancer cells on HG/LG-glioma-associated stem cells was studied by time-lapse microscopy, while cell deformability and cell-cell adhesion strengths were quantified by indentation measurements by atomic force microscopy and single cell force spectroscopy. Our results demonstrate that for both HG and LG glioma, cancer-initiating-stem cells are softer than glioma-associated-stem cells, in agreement with their neoplastic features. The adhesion strength of GSC on GASC appears to be significantly lower than that observed for Gsc on Gasc. Whereas, GSC spread and firmly adhere on Gasc with an adhesion strength increased as compared to that obtained on GASC. These findings highlight that the grade of glioma-associated-stem cells plays an important role in modulating cancer cell adhesion, which could affect glioma cell migration, invasion and thus cancer aggressiveness. Moreover this work provides evidence about the importance of investigating cell adhesion and elasticity for new developments in disease diagnostics and therapeutics.

  12. Correlation between E-cadherin-regulated cell adhesion and human osteosarcoma MG-63 cell anoikis.

    Science.gov (United States)

    Lin, Ding-Sheng; Cai, Le-Yi; Ding, Jian; Gao, Wei-Yang

    2014-01-01

    The aim of this study was to investigate the relationship between cell adhesion and anoikis evasion among human osteosarcoma cells (MG-63), and to further study the molecular mechanisms. Human osteosarcoma cells (MG-63) were assessed for apoptosis, and caspase-3, E-cadherin and β-catenin expression in EDTA and control non-EDTA groups. MG-63 cells were predominantly aggregated when in suspension, and the suspended cells were more dispersed in the EDTA group. Following culture in suspension for 24 h, 48 h, or 72 h, the rates of apoptosis were 34.88%±3.64%, 59.3%±7.22% and 78.5%±5.21% in the experimental group and 7.34%±2.13%, 14.7%±3.69%, and 21.4%±3.60% in the control group, respectively. Caspase-3 expression progressively increased and E-cadherin and β-catenin were decreased in the experimental group, whereas there was no change in the control group. MG-63 cells could avoid anoikis through cell adhesion, and E-cadherin might play a role in this process.

  13. Impairment of lymphocyte adhesion to cultured fibroblasts and endothelial cells by γ-irradiation

    International Nuclear Information System (INIS)

    Piela-Smith, T.H.; Aneiro, L.; Nuveen, E.; Korn, J.H.; Aune, T.

    1992-01-01

    A critical component of immune responsiveness is the localization of effector cells at sites of inflammatory lesions. Adhesive molecules that may play a role in this process have been described on the surfaces of both lymphocytes and connective tissue cells. Adhesive interactions of T lymphocytes with fibroblasts or endothelial cells can be inhibited by preincubation of the fibroblasts or endothelial cells with antibody to intercellular adhesion molecule 1 (CD54) or by preincubation of the T cells with antibody to lymphocyte function-associated Ag 1 (CD11a/CD18), molecules shown to be important in several other cell-cell adhesion interactions. Here the authors show that γ-irradiation of human T lymphocytes impaired their ability to adhere to both fibroblasts and endothelial cells. This impairment was not associated with a loss of cell viability or of cell surface lymphocyte function-associated Ag 1 expression. γ-Irradiation of T cells is known to result in the activation of ADP-ribosyltransferase, an enzyme involved in DNA strand-break repair, causing subsequent depletion of cellular nicotinamide adenine dinucleotide (NAD) pools by increasing NAD consumption for poly(ADP-ribose) formation. Preincubation of T cells with either nicotinamide or 3-aminobenzamide, both known inhibitors of ADP-ribosyltransferase, completely reversed the suppressive effects of γ-irradiation on T cell adhesion. The maintenance of adhesion was accompanied by inhibition of irradiation-induced depletion of cellular NAD. These experiments suggest that the impairment of cellular immune function after irradiation in vivo may be caused, in part, by defective T cell emigration and localization at inflammatory sites. 44 refs., 5 figs., 3 tabs

  14. Quantitative analysis of dynamic adhesion properties in human hepatocellular carcinoma cells with fullerenol.

    Science.gov (United States)

    Liu, Yang; Wang, Zuobin; Wang, Xinyue; Huang, Yanhong

    2015-12-01

    In this study, the effect of fullerenol (C60(OH)24) on the cellular dynamic biomechanical behaviors of living human hepatocellular carcinoma (SMCC-7721) cancer cells were investigated by atomic force microscope (AFM) nanoindentation. As an important biomarker of cellular information, the cell adhesion is essential to maintain proper functioning as well as links with the pathogenesis and canceration. Nonetheless, it is challenging to properly evaluate the complex adhesion properties as all the biomechanical parameters interfere with each other. To investigate the dynamic adhesion changes, especially in the case of the fullerenol treatment, the detachment force and work, adhesion events, and membrane tether properties were measured and analyzed systematically with the proposed quantitative method. The statistical analyses suggest that, under the same operating parameters of AFM, the dependence of adhesion energy on the tip-cell contact area is weakened after the fullerenol treatment and the probability of adhesion decreases significantly from 30.6% to 4.2%. In addition, the disruption of the cytoskeleton resulted in a 34% decrease of the average membrane tether force and a 21% increase of the average tether length. Benefiting from the quantitative method, this work contributes to revealing the effects of fullerenol on the cellular biomechanical properties of the living SMCC-7721 cells in a precise and rigorous way and additionally is further instructive to interpret the interaction mechanism of other potential nanomedicines with living cells. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. The relative importance of topography and RGD ligand density for endothelial cell adhesion.

    Directory of Open Access Journals (Sweden)

    Guillaume Le Saux

    Full Text Available The morphology and function of endothelial cells depends on the physical and chemical characteristics of the extracellular environment. Here, we designed silicon surfaces on which topographical features and surface densities of the integrin binding peptide arginine-glycine-aspartic acid (RGD could be independently controlled. We used these surfaces to investigate the relative importance of the surface chemistry of ligand presentation versus surface topography in endothelial cell adhesion. We compared cell adhesion, spreading and migration on surfaces with nano- to micro-scaled pyramids and average densities of 6×10(2-6×10(11 RGD/mm(2. We found that fewer cells adhered onto rough than flat surfaces and that the optimal average RGD density for cell adhesion was 6×10(5 RGD/mm(2 on flat surfaces and substrata with nano-scaled roughness. Only on surfaces with micro-scaled pyramids did the topography hinder cell migration and a lower average RGD density was optimal for adhesion. In contrast, cell spreading was greatest on surfaces with 6×10(8 RGD/mm(2 irrespectively of presence of feature and their size. In summary, our data suggest that the size of pyramids predominately control the number of endothelial cells that adhere to the substratum but the average RGD density governs the degree of cell spreading and length of focal adhesion within adherent cells. The data points towards a two-step model of cell adhesion: the initial contact of cells with a substratum may be guided by the topography while the engagement of cell surface receptors is predominately controlled by the surface chemistry.

  16. Cell adhesive affinity does not dictate primitive endoderm segregation and positioning during murine embryoid body formation.

    Science.gov (United States)

    Moore, Robert; Cai, Kathy Q; Escudero, Diogo O; Xu, Xiang-Xi

    2009-09-01

    The classical cell sorting experiments undertaken by Townes and Holtfreter described the intrinsic propensity of dissociated embryonic cells to self-organize and reconcile into their original embryonic germ layers with characteristic histotypic positioning. Steinberg presented the differential adhesion hypothesis to explain these patterning phenomena. Here, we have reappraised these issues by implementing embryoid bodies to model the patterning of epiblast and primitive endoderm layers. We have used combinations of embryonic stem (ES) cells and their derivatives differentiated by retinoic acid treatment to model epiblast and endoderm cells, and wild-type or E-cadherin null cells to represent strongly or weakly adherent cells, respectively. One cell type was fluorescently labeled and reconstituted with another heterotypically to generate chimeric embryoid bodies, and cell sorting was tracked by time-lapse video microscopy and confirmed by immunostaining. When undifferentiated wild-type and E-cadherin null ES cells were mixed, the resulting cell aggregates consisted of a core of wild-type cells surrounded by loosely associated E-cadherin null cells, consistent with the differential adhesion hypothesis. However, when mixed with undifferentiated ES cells, the differentiated primitive endoderm-like cells sorted to the surface to form a primitive endoderm layer irrespective of cell-adhesive strength, contradicting the differential adhesion hypothesis. We propose that the primitive endoderm cells reach the surface by random movement, and subsequently the cells generate an apical/basal polarity that prevents reentry. Thus, the ability to generate epithelial polarity, rather than adhesive affinity, determines the surface positioning of the primitive endoderm cells. (c) 2009 Wiley-Liss, Inc.

  17. RP1 is a phosphorylation target of CK2 and is involved in cell adhesion.

    Science.gov (United States)

    Stenner, Frank; Liewen, Heike; Göttig, Stephan; Henschler, Reinhard; Markuly, Norbert; Kleber, Sascha; Faust, Michael; Mischo, Axel; Bauer, Stefan; Zweifel, Martin; Knuth, Alexander; Renner, Christoph; Wadle, Andreas

    2013-01-01

    RP1 (synonym: MAPRE2, EB2) is a member of the microtubule binding EB1 protein family, which interacts with APC, a key regulatory molecule in the Wnt signalling pathway. While the other EB1 proteins are well characterized the cellular function and regulation of RP1 remain speculative to date. However, recently RP1 has been implicated in pancreatic cancerogenesis. CK2 is a pleiotropic kinase involved in adhesion, proliferation and anti-apoptosis. Overexpression of protein kinase CK2 is a hallmark of many cancers and supports the malignant phenotype of tumor cells. In this study we investigate the interaction of protein kinase CK2 with RP1 and demonstrate that CK2 phosphorylates RP1 at Ser(236) in vitro. Stable RP1 expression in cell lines leads to a significant cleavage and down-regulation of N-cadherin and impaired adhesion. Cells expressing a Phospho-mimicking point mutant RP1-ASP(236) show a marked decrease of adhesion to endothelial cells under shear stress. Inversely, we found that the cells under shear stress downregulate endogenous RP1, most likely to improve cellular adhesion. Accordingly, when RP1 expression is suppressed by shRNA, cells lacking RP1 display significantly increased cell adherence to surfaces. In summary, RP1 phosphorylation at Ser(236) by CK2 seems to play a significant role in cell adhesion and might initiate new insights in the CK2 and EB1 family protein association.

  18. RP1 is a phosphorylation target of CK2 and is involved in cell adhesion.

    Directory of Open Access Journals (Sweden)

    Frank Stenner

    Full Text Available RP1 (synonym: MAPRE2, EB2 is a member of the microtubule binding EB1 protein family, which interacts with APC, a key regulatory molecule in the Wnt signalling pathway. While the other EB1 proteins are well characterized the cellular function and regulation of RP1 remain speculative to date. However, recently RP1 has been implicated in pancreatic cancerogenesis. CK2 is a pleiotropic kinase involved in adhesion, proliferation and anti-apoptosis. Overexpression of protein kinase CK2 is a hallmark of many cancers and supports the malignant phenotype of tumor cells. In this study we investigate the interaction of protein kinase CK2 with RP1 and demonstrate that CK2 phosphorylates RP1 at Ser(236 in vitro. Stable RP1 expression in cell lines leads to a significant cleavage and down-regulation of N-cadherin and impaired adhesion. Cells expressing a Phospho-mimicking point mutant RP1-ASP(236 show a marked decrease of adhesion to endothelial cells under shear stress. Inversely, we found that the cells under shear stress downregulate endogenous RP1, most likely to improve cellular adhesion. Accordingly, when RP1 expression is suppressed by shRNA, cells lacking RP1 display significantly increased cell adherence to surfaces. In summary, RP1 phosphorylation at Ser(236 by CK2 seems to play a significant role in cell adhesion and might initiate new insights in the CK2 and EB1 family protein association.

  19. Controlling cell adhesion via replication of laser micro/nano-textured surfaces on polymers

    Energy Technology Data Exchange (ETDEWEB)

    Koufaki, Niki; Ranella, Anthi; Barberoglou, Marios; Psycharakis, Stylianos; Fotakis, Costas; Stratakis, Emmanuel [Institute of Electronic Structure and Laser (IESL), Foundation for Research and Technology-Hellas (FORTH), 711 10, Heraklion, Crete (Greece); Aifantis, Katerina E, E-mail: stratak@iesl.forth.gr [Lab of Mechanics and Materials, Aristotle University of Thessaloniki, Thessaloniki (Greece)

    2011-12-15

    The aim of this study is to investigate cell adhesion and viability on highly rough polymeric surfaces with gradient roughness ratios and wettabilities prepared by microreplication of laser micro/nano-textured Si surfaces. Negative replicas on polydimethylsiloxane as well as positive ones on a photocurable (organically modified ceramic) and a biodegradable (poly(lactide-co-glycolide)) polymer have been successfully reproduced. The final culture substrates comprised from forests of micron-sized conical spikes exhibiting a range of roughness ratios and wettabilities, was achieved by changing the laser fluence used to fabricate the original template surfaces. Cell culture experiments were performed with the fibroblast NIH/3T3 and PC12 neuronal cell lines in order to investigate how these surfaces are capable of modulating different types of cellular responses including, viability, adhesion and morphology. The results showed a preferential adhesion of both cell types on the microstructured surfaces compared to the unstructured ones. In particular, the fibroblast NIH/3T3 cells show optimal adhesion for small roughness ratios, independent of the surface wettability and polymer type, indicating a non-monotonic dependence of cell adhesion on surface energy. In contrast, the PC12 cells were observed to adhere well to the patterned surfaces independent of the roughness ratio and wettability. These experimental findings are correlated with micromechanical measurements performed on the unstructured and replicated surfaces and discussed on the basis of previous observations describing the relation of cell response to surface energy and rigidity.

  20. Controlling cell adhesion via replication of laser micro/nano-textured surfaces on polymers

    International Nuclear Information System (INIS)

    Koufaki, Niki; Ranella, Anthi; Barberoglou, Marios; Psycharakis, Stylianos; Fotakis, Costas; Stratakis, Emmanuel; Aifantis, Katerina E

    2011-01-01

    The aim of this study is to investigate cell adhesion and viability on highly rough polymeric surfaces with gradient roughness ratios and wettabilities prepared by microreplication of laser micro/nano-textured Si surfaces. Negative replicas on polydimethylsiloxane as well as positive ones on a photocurable (organically modified ceramic) and a biodegradable (poly(lactide-co-glycolide)) polymer have been successfully reproduced. The final culture substrates comprised from forests of micron-sized conical spikes exhibiting a range of roughness ratios and wettabilities, was achieved by changing the laser fluence used to fabricate the original template surfaces. Cell culture experiments were performed with the fibroblast NIH/3T3 and PC12 neuronal cell lines in order to investigate how these surfaces are capable of modulating different types of cellular responses including, viability, adhesion and morphology. The results showed a preferential adhesion of both cell types on the microstructured surfaces compared to the unstructured ones. In particular, the fibroblast NIH/3T3 cells show optimal adhesion for small roughness ratios, independent of the surface wettability and polymer type, indicating a non-monotonic dependence of cell adhesion on surface energy. In contrast, the PC12 cells were observed to adhere well to the patterned surfaces independent of the roughness ratio and wettability. These experimental findings are correlated with micromechanical measurements performed on the unstructured and replicated surfaces and discussed on the basis of previous observations describing the relation of cell response to surface energy and rigidity.

  1. Neural cell adhesion molecule (NCAM) marks adult myogenic cells committed to differentiation

    International Nuclear Information System (INIS)

    Capkovic, Katie L.; Stevenson, Severin; Johnson, Marc C.; Thelen, Jay J.; Cornelison, D.D.W.

    2008-01-01

    Although recent advances in broad-scale gene expression analysis have dramatically increased our knowledge of the repertoire of mRNAs present in multiple cell types, it has become increasingly clear that examination of the expression, localization, and associations of the encoded proteins will be critical for determining their functional significance. In particular, many signaling receptors, transducers, and effectors have been proposed to act in higher-order complexes associated with physically distinct areas of the plasma membrane. Adult muscle stem cells (satellite cells) must, upon injury, respond appropriately to a wide range of extracellular stimuli: the role of such signaling scaffolds is therefore a potentially important area of inquiry. To address this question, we first isolated detergent-resistant membrane fractions from primary satellite cells, then analyzed their component proteins using liquid chromatography-tandem mass spectrometry. Transmembrane and juxtamembrane components of adhesion-mediated signaling pathways made up the largest group of identified proteins; in particular, neural cell adhesion molecule (NCAM), a multifunctional cell-surface protein that has previously been associated with muscle regeneration, was significant. Immunohistochemical analysis revealed that not only is NCAM localized to discrete areas of the plasma membrane, it is also a very early marker of commitment to terminal differentiation. Using flow cytometry, we have sorted physically homogeneous myogenic cultures into proliferating and differentiating fractions based solely upon NCAM expression

  2. Quantifying cellular mechanics and adhesion in renal tubular injury using single cell force spectroscopy.

    Science.gov (United States)

    Siamantouras, Eleftherios; Hills, Claire E; Squires, Paul E; Liu, Kuo-Kang

    2016-05-01

    Tubulointerstitial fibrosis represents the major underlying pathology of diabetic nephropathy where loss of cell-to-cell adhesion is a critical step. To date, research has predominantly focussed on the loss of cell surface molecular binding events that include altered protein ligation. In the current study, atomic force microscopy single cell force spectroscopy (AFM-SCFS) was used to quantify changes in cellular stiffness and cell adhesion in TGF-β1 treated kidney cells of the human proximal tubule (HK2). AFM indentation of TGF-β1 treated HK2 cells showed a significant increase (42%) in the elastic modulus (stiffness) compared to control. Fluorescence microscopy confirmed that increased cell stiffness is accompanied by reorganization of the cytoskeleton. The corresponding changes in stiffness, due to F-actin rearrangement, affected the work of detachment by changing the separation distance between two adherent cells. Overall, our novel data quantitatively demonstrate a correlation between cellular elasticity, adhesion and early morphologic/phenotypic changes associated with tubular injury. Diabetes affects many patients worldwide. One of the long term problems is diabetic nephropathy. Here, the authors utilized atomic force microscopy single cell force spectroscopy (AFM- SCFS) to study cellular stiffness and cell adhesion after TGF1 treatment in human proximal tubule kidney cells. The findings would help further understand the overall disease mechanism in diabetic patients. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Dopaminergic enhancement of cellular adhesion in bone marrow derived mesenchymal stem cells (MSCs).

    Science.gov (United States)

    Chen, Si; Bai, Bing; Lee, Dong Joon; Diachina, Shannon; Li, Yina; Wong, Sing Wai; Wang, Zhengyan; Tseng, Henry C; Ko, Ching-Chang

    2017-08-01

    Dopamine (DA) is a well-known neurotransmitter and critical element in the mussel adhesive protein that has gained increasing attention for its role in cellular growth enhancement in biomaterials, including cellular adhesion improvement. As the mechanism underlying this remains unclear, the objective of this study was to explore the effects of DA on the adhesion properties of bone marrow derived rat mesenchymal stem cells (rMSCs) using an hydroxyapatite gelatin nanocomposite biomaterial and to test whether the effects are mediated through various endogenously expressed DA receptors. Primary rMSCs were pretreated with D1-like antagonist, D2-like antagonist, or a combination of these antagonists followed by treatment with 50 μM DA and cellular adhesion quantification at 0.5, 1, 2 and 4 hours post DA addition. DA was found to increase rMSC adhesion and spreading at the 0.5 hour time-point and the dopaminergic effect on cell adhesion was partially blocked by DA antagonists. In addition, the D1-like and D2-like antagonists appeared to have a similar effect on rMSCs. Immunofluorescent staining indicated that the rMSC spreading area was significantly increased in the DA treated group versus the control group. Treatment of the D1-like DA antagonists with DA revealed that the actin filaments of rMSCs could not connect the membrane with the nucleus. In summary, DA was found to enhance early rMSC adhesion partially via DA receptor activation.

  4. Adhesion, biofilm formation, cell surface hydrophobicity and antifungal planktonic susceptibility: relationship among Candida spp.

    Directory of Open Access Journals (Sweden)

    Ana Isabel Silva-Dias

    2015-03-01

    Full Text Available We have performed the characterization of the adhesion profile, biofilm formation, cell surface hydrophobicity (CSH and antifungal susceptibility of 184 Candida clinical isolates obtained from different human reservoirs. Adhesion was quantified using a flow cytometric assay and biofilm formation was evaluated using two methodologies: XTT and crystal violet assay. CSH was quantified with the microbial adhesion to hydrocarbons test while planktonic susceptibility was assessed accordingly the CLSI protocol for yeast M27-A3 S4.Yeast cells of non-albicans species exhibit increased ability to adhere and form biofilm. However the correlation between adhesion and biofilm formation varied according to species and also with the methodology used for biofilm assessment. No association was found between strain´s site of isolation or planktonic antifungal susceptibility and adhesion or biofilm formation. Finally CSH seemed to be a good predictor for biofilm formation but not for adhesion.Despite the marked variability registered intra and inter species, C. tropicalis and C. parapsilosis were the species exhibiting high adhesion profile. C. tropicalis, C. guilliermondii and C. krusei revealed higher biofilm formation values in terms of biomass. C. parapsilosis was the species with lower biofilm metabolic activity.

  5. Adhesion, biofilm formation, cell surface hydrophobicity, and antifungal planktonic susceptibility: relationship among Candida spp.

    Science.gov (United States)

    Silva-Dias, Ana; Miranda, Isabel M; Branco, Joana; Monteiro-Soares, Matilde; Pina-Vaz, Cidália; Rodrigues, Acácio G

    2015-01-01

    We have performed the characterization of the adhesion profile, biofilm formation, cell surface hydrophobicity (CSH) and antifungal susceptibility of 184 Candida clinical isolates obtained from different human reservoirs. Adhesion was quantified using a flow cytometric assay and biofilm formation was evaluated using two methodologies: XTT and crystal violet assay. CSH was quantified with the microbial adhesion to hydrocarbons test while planktonic susceptibility was assessed accordingly the CLSI protocol for yeast M27-A3 S4. Yeast cells of non-albicans species exhibit increased ability to adhere and form biofilm. However, the correlation between adhesion and biofilm formation varied according to species and also with the methodology used for biofilm assessment. No association was found between strain's site of isolation or planktonic antifungal susceptibility and adhesion or biofilm formation. Finally CSH seemed to be a good predictor for biofilm formation but not for adhesion. Despite the marked variability registered intra and inter species, C. tropicalis and C. parapsilosis were the species exhibiting high adhesion profile. C. tropicalis, C. guilliermondii, and C. krusei revealed higher biofilm formation values in terms of biomass. C. parapsilosis was the species with lower biofilm metabolic activity.

  6. Interactions with nanoscale topography: adhesion quantification and signal transduction in cells of osteogenic and multipotent lineage.

    Science.gov (United States)

    Biggs, Manus J P; Richards, R Geoff; Gadegaard, Nikolaj; McMurray, Rebecca J; Affrossman, Stanley; Wilkinson, Chris D W; Oreffo, Richard O C; Dalby, Mathew J

    2009-10-01

    Polymeric medical devices widely used in orthopedic surgery play key roles in fracture fixation and orthopedic implant design. Topographical modification and surface micro-roughness of these devices regulate cellular adhesion, a process fundamental in the initiation of osteoinduction and osteogenesis. Advances in fabrication techniques have evolved the field of surface modification; in particular, nanotechnology has allowed the development of nanoscale substrates for the investigation into cell-nanofeature interactions. In this study human osteoblasts (HOBs) were cultured on ordered nanoscale pits and random nano "craters" and "islands". Adhesion subtypes were quantified by immunofluorescent microscopy and cell-substrate interactions investigated via immuno-scanning electron microscopy. To investigate the effects of these substrates on cellular function 1.7 k microarray analysis was used to establish gene profiles of enriched STRO-1+ progenitor cell populations cultured on these nanotopographies. Nanotopographies affected the formation of adhesions on experimental substrates. Adhesion formation was prominent on planar control substrates and reduced on nanocrater and nanoisland topographies; nanopits, however, were shown to inhibit directly the formation of large adhesions. STRO-1+ progenitor cells cultured on experimental substrates revealed significant changes in genetic expression. This study implicates nanotopographical modification as a significant modulator of osteoblast adhesion and cellular function in mesenchymal populations.

  7. Cell adhesion to fibrillin-1: identification of an Arg-Gly-Asp-dependent synergy region and a heparin-binding site that regulates focal adhesion formation

    DEFF Research Database (Denmark)

    Bax, Daniel V; Mahalingam, Yashithra; Cain, Stuart

    2007-01-01

    We have defined the molecular basis of cell adhesion to fibrillin-1, the major structural component of extracellular microfibrils that are associated with elastic fibres. Using human dermal fibroblasts, and recombinant domain swap fragments containing the Arg-Gly-Asp motif, we have demonstrated...... a requirement for upstream domains for integrin-alpha(5)beta(1)-mediated cell adhesion and migration. An adjacent heparin-binding site, which supports focal adhesion formation, was mapped to the fibrillin-1 TB5 motif. Site-directed mutagenesis revealed two arginine residues that are crucial for heparin binding...

  8. Cell Adhesion Selectivity of Stent Material to improve Bio-functionality by Ion Beam Modification

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jaesang; Park, JUngchan; Jung, Myunghwan; Kim, Yongki [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Park, Junkyu [Bio alpha., Co. Ltd., Gimhae (Korea, Republic of)

    2014-05-15

    In this study, ion implantation into collagen coated Co-Cr alloy, which is a cheaper material of the artificial stent product comparing with Ti alloy, has been studied to develop small diameter artificial stent by the cell adhesion control. The size of stent was 1.6mm of the diameter and 18mm of the length. The life-time of artificial stent depends on adhesion property of endothelial-cells. We successfully controlled cell adhesion selectivity between endothelial cell and muscle cell by using collagen coated and He{sup +} ion beam irradiated Co-Cr-alloy to apply to artificial stent. But, we did not achieve the inhibition of platelet adhesion, yet by using collagen coating and He{sup +} ion beam irradiation. Based on this study, we have plan to research about separation between collagen coating effect and ion beam effect. Also, we will have more detail analysis of the mechanism of cell attachment. In recent years, ion implantation has been applied to the surface modification of prosthesis to improve blood compatibility and tissue compatibility in field of biomedical application. As well known, bio compatibility was concerned with the cell adhesion selectivity for bio-functionality. The biomedical application of ion beam technology would be used more widely in the future such as catheter and artificial graft.

  9. Cell Adhesion Selectivity of Stent Material to improve Bio-functionality by Ion Beam Modification

    International Nuclear Information System (INIS)

    Lee, Jaesang; Park, JUngchan; Jung, Myunghwan; Kim, Yongki; Park, Junkyu

    2014-01-01

    In this study, ion implantation into collagen coated Co-Cr alloy, which is a cheaper material of the artificial stent product comparing with Ti alloy, has been studied to develop small diameter artificial stent by the cell adhesion control. The size of stent was 1.6mm of the diameter and 18mm of the length. The life-time of artificial stent depends on adhesion property of endothelial-cells. We successfully controlled cell adhesion selectivity between endothelial cell and muscle cell by using collagen coated and He + ion beam irradiated Co-Cr-alloy to apply to artificial stent. But, we did not achieve the inhibition of platelet adhesion, yet by using collagen coating and He + ion beam irradiation. Based on this study, we have plan to research about separation between collagen coating effect and ion beam effect. Also, we will have more detail analysis of the mechanism of cell attachment. In recent years, ion implantation has been applied to the surface modification of prosthesis to improve blood compatibility and tissue compatibility in field of biomedical application. As well known, bio compatibility was concerned with the cell adhesion selectivity for bio-functionality. The biomedical application of ion beam technology would be used more widely in the future such as catheter and artificial graft

  10. The Role of Immunoglobulin Superfamily Cell Adhesion Molecules in Cancer Metastasis

    Directory of Open Access Journals (Sweden)

    Chee Wai Wong

    2012-01-01

    Full Text Available Metastasis is a major clinical problem and results in a poor prognosis for most cancers. The metastatic pathway describes the process by which cancer cells give rise to a metastatic lesion in a new tissue or organ. It consists of interconnecting steps all of which must be successfully completed to result in a metastasis. Cell-cell adhesion is a key aspect of many of these steps. Adhesion molecules belonging to the immunoglobulin superfamily (Ig-SF commonly play a central role in cell-cell adhesion, and a number of these molecules have been associated with cancer progression and a metastatic phenotype. Surprisingly, the contribution of Ig-SF members to metastasis has not received the attention afforded other cell adhesion molecules (CAMs such as the integrins. Here we examine the steps in the metastatic pathway focusing on how the Ig-SF members, melanoma cell adhesion molecule (MCAM, L1CAM, neural CAM (NCAM, leukocyte CAM (ALCAM, intercellular CAM-1 (ICAM-1 and platelet endothelial CAM-1 (PECAM-1 could play a role. Although much remains to be understood, this review aims to raise the profile of Ig-SF members in metastasis formation and prompt further research that could lead to useful clinical outcomes.

  11. Single cell adhesion strength assessed with variable-angle total internal reflection fluorescence microscopy

    Directory of Open Access Journals (Sweden)

    Marcelina Cardoso Dos Santos

    2017-06-01

    Full Text Available We propose a new strategy to evaluate adhesion strength at the single cell level. This approach involves variable-angle total internal reflection fluorescence microscopy to monitor in real time the topography of cell membranes, i.e. a map of the membrane/substrate separation distance. According to the Boltzmann distribution, both potential energy profile and dissociation energy related to the interactions between the cell membrane and the substrate were determined from the membrane topography. We have highlighted on glass substrates coated with poly-L-lysine and fibronectin, that the dissociation energy is a reliable parameter to quantify the adhesion strength of MDA-MB-231 motile cells.

  12. Coupling biochemistry and mechanics in cell adhesion: a model for inhomogeneous stress fiber contraction

    International Nuclear Information System (INIS)

    Besser, Achim; Schwarz, Ulrich S

    2007-01-01

    Biochemistry and mechanics are closely coupled in cell adhesion. At sites of cell-matrix adhesion, mechanical force triggers signaling through the Rho-pathway, which leads to structural reinforcement and increased contractility in the actin cytoskeleton. The resulting force acts back to the sites of adhesion, resulting in a positive feedback loop for mature adhesion. Here, we model this biochemical-mechanical feedback loop for the special case when the actin cytoskeleton is organized in stress fibers, which are contractile bundles of actin filaments. Activation of myosin II molecular motors through the Rho-pathway is described by a system of reaction-diffusion equations, which are coupled into a viscoelastic model for a contractile actin bundle. We find strong spatial gradients in the activation of contractility and in the corresponding deformation pattern of the stress fiber, in good agreement with experimental findings

  13. [Effects of selenium compounds on proliferation, migration and adhesion of HeLa cells].

    Science.gov (United States)

    Sun, Licui; Lu, Jiaxi; Wang, Qin; Liu, Yiqun; Han, Feng; Yang, Yanhua; Zhang, Hongkun; Huang, Zhenwu

    2015-03-01

    To explore the effects of methylseleninic acid (MeSeA), selenomethionine (SeMet) and methylselenocysteine (MeSeCys) on proliferation, migration and adhesion of HeLa cells. HeLa cells were cultured and treated with MeSeA, SeMet and MeSeCys for 12 - 72 h respectively. MTT assay, healing assay and in vitro cell Matrigel adhesion assay were used to detect the proliferation, migration and adhesion of HeLa cells. Compared to the control group, the proliferation of HeLa cells was remarkably inhibited by MeSeA (P HeLa cells in MeSeA group was inhibited by 34% (P HeLa cells with inhibitions of 18% and 13% was in SeMet group in 4 h and 8 h. The inhibitions of HeLa cell migration in MeSeCys group was 28% (P HeLa cells in the MeSeA group, the SeMet group as well as the MeSeCys group were inhibited by 36% (P HeLa cell were effectively inhibited by MeSeA, while the adhesive function of HeLa cell was remarkably inhibited by MeSeCys.

  14. Cell adhesion and EGFR activation regulate EphA2 expression in cancer

    DEFF Research Database (Denmark)

    Larsen, Alice Bjerregaard; Stockhausen, Marie-Thérése; Poulsen, Hans Skovgaard

    2010-01-01

    largely unknown. Here we show that the expression of EphA2 in in vitro cultured cells, is restricted to cells growing adherently and that adhesion-induced EphA2 expression is dependent upon activation of the epidermal growth factor receptor (EGFR), mitogen activated protein kinase kinase (MEK) and Src...... family kinases (SRC). Moreover, the results show that adhesion-induced EGFR activation and EphA2 expression is affected by interactions with extracellular matrix (ECM) proteins working as integrin ligands. Stimulation with the EphA2 ligand, ephrinA1 inhibited ERK phosphorylation and cancer cell viability....... These effects were however abolished by activation of the EGF-receptor ligand system favoring Ras/MAPK signaling and cell proliferation. Based on our results, we propose a regulatory mechanism where cell adhesion induces EGFR kinase activation and EphA2 expression; and where the effect of ephrinA1 mediated...

  15. Preparation and regulating cell adhesion of anion-exchangeable layered double hydroxide micropatterned arrays.

    Science.gov (United States)

    Yao, Feng; Hu, Hao; Xu, Sailong; Huo, Ruijie; Zhao, Zhiping; Zhang, Fazhi; Xu, Fujian

    2015-02-25

    We describe a reliable preparation of MgAl-layered double hydroxide (MgAl-LDH) micropatterned arrays on gold substrate by combining SO3(-)-terminated self-assembly monolayer and photolithography. The synthesis route is readily extended to prepare LDH arrays on the SO3(-)-terminated polymer-bonded glass substrate amenable for cell imaging. The anion-exchangeable MgAl-LDH micropattern can act both as bioadhesive region for selective cell adhesion and as nanocarrier for drug molecules to regulate cell behaviors. Quantitative analysis of cell adhesion shows that selective HepG2 cell adhesion and spreading are promoted by the micropatterned MgAl-LDH, and also suppressed by methotrexate drug released from the LDH interlayer galleries.

  16. Aging effects of plasma polymerized ethylenediamine (PPEDA) thin films on cell-adhesive implant coatings

    International Nuclear Information System (INIS)

    Testrich, H.; Rebl, H.; Finke, B.; Hempel, F.; Nebe, B.; Meichsner, J.

    2013-01-01

    Thin plasma polymer films from ethylenediamine were deposited on planar substrates placed on the powered electrode of a low pressure capacitively coupled 13.56 MHz discharge. The chemical composition of the plasma polymer films was analyzed by Fourier Transform Infrared Reflection Absorption Spectroscopy (FT-IRRAS) as well as by X-ray photoelectron spectroscopy (XPS) after derivatization of the primary amino groups. The PPEDA films undergo an alteration during the storage in ambient air, particularly, due to reactions with oxygen. The molecular changes in PPEDA films were studied over a long-time period of 360 days. Simultaneously, the adhesion of human osteoblast-like cells MG-63 (ATCC) was investigated on PPEDA coated corundum blasted titanium alloy (Ti-6Al-4V), which is applied as implant material in orthopedic surgery. The cell adhesion was determined by flow cytometry and the cell shape was analyzed by scanning electron microscopy. Compared to uncoated reference samples a significantly enhanced cell adhesion and proliferation were measured for PPEDA coated samples, which have been maintained after long-time storage in ambient air and additional sterilization by γ−irradiation. - Highlights: • Development of cell-adhesive nitrogen-rich coatings for biomedical applications. • Plasma polymer films from low pressure 13.56 MHz discharge in argon-ethylenediamine. • Enhanced osteoblast adhesion/proliferation on coated implant material (Ti-6Al-4V). • Despite film aging over 360 days the enhanced cell adhesion of the coating remains. • No influence of additional y-sterilization on the enhanced cell adhesion

  17. Bio-active molecules modified surfaces enhanced mesenchymal stem cell adhesion and proliferation

    International Nuclear Information System (INIS)

    Mobasseri, Rezvan; Tian, Lingling; Soleimani, Masoud; Ramakrishna, Seeram; Naderi-Manesh, Hossein

    2017-01-01

    Surface modification of the substrate as a component of in vitro cell culture and tissue engineering, using bio-active molecules including extracellular matrix (ECM) proteins or peptides derived ECM proteins can modulate the surface properties and thereby induce the desired signaling pathways in cells. The aim of this study was to evaluate the behavior of human bone marrow mesenchymal stem cells (hBM-MSCs) on glass substrates modified with fibronectin (Fn), collagen (Coll), RGD peptides (RGD) and designed peptide (R-pept) as bio-active molecules. The glass coverslips were coated with fibronectin, collagen, RGD peptide and R-peptide. Bone marrow mesenchymal stem cells were cultured on different substrates and the adhesion behavior in early incubation times was investigated using scanning electron microscopy (SEM) and confocal microscopy. The MTT assay was performed to evaluate the effect of different bio-active molecules on MSCs proliferation rate during 24 and 72 h. Formation of filopodia and focal adhesion (FA) complexes, two steps of cell adhesion process, were observed in MSCs cultured on bio-active molecules modified coverslips, specifically in Fn coated and R-pept coated groups. SEM image showed well adhesion pattern for MSCs cultured on Fn and R-pept after 2 h incubation, while the shape of cells cultured on Coll and RGD substrates indicated that they might experience stress condition in early hours of culture. Investigation of adhesion behavior, as well as proliferation pattern, suggests R-peptide as a promising bio-active molecule to be used for surface modification of substrate in supporting and inducing cell adhesion and proliferation. - Highlights: • Bioactive molecules modified surface is a strategy to design biomimicry scaffold. • Bi-functional Tat-derived peptide (R-pept) enhanced MSCs adhesion and proliferation. • R-pept showed similar influences to fibronectin on FA formation and attachment.

  18. Vascular smooth muscle cell stiffness and adhesion to collagen I modified by vasoactive agonists.

    Directory of Open Access Journals (Sweden)

    Zhongkui Hong

    Full Text Available In vascular smooth muscle cells (VSMCs integrin-mediated adhesion to extracellular matrix (ECM proteins play important roles in sustaining vascular tone and resistance. The main goal of this study was to determine whether VSMCs adhesion to type I collagen (COL-I was altered in parallel with the changes in the VSMCs contractile state induced by vasoconstrictors and vasodilators. VSMCs were isolated from rat cremaster skeletal muscle arterioles and maintained in primary culture without passage. Cell adhesion and cell E-modulus were assessed using atomic force microscopy (AFM by repetitive nano-indentation of the AFM probe on the cell surface at 0.1 Hz sampling frequency and 3200 nm Z-piezo travelling distance (approach and retraction. AFM probes were tipped with a 5 μm diameter microbead functionalized with COL-I (1 mg\\ml. Results showed that the vasoconstrictor angiotensin II (ANG-II; 10-6 significantly increased (p<0.05 VSMC E-modulus and adhesion probability to COL-I by approximately 35% and 33%, respectively. In contrast, the vasodilator adenosine (ADO; 10-4 significantly decreased (p<0.05 VSMC E-modulus and adhesion probability by approximately -33% and -17%, respectively. Similarly, the NO donor (PANOate, 10-6 M, a potent vasodilator, also significantly decreased (p<0.05 the VSMC E-modulus and COL-I adhesion probability by -38% and -35%, respectively. These observations support the hypothesis that integrin-mediated VSMC adhesion to the ECM protein COL-I is dynamically regulated in parallel with VSMC contractile activation. These data suggest that the signal transduction pathways modulating VSMC contractile activation and relaxation, in addition to ECM adhesion, interact during regulation of contractile state.

  19. Mesenchymal stem cell adhesion but not plasticity is affected by high substrate stiffness

    Directory of Open Access Journals (Sweden)

    Janice Kal Van Tam, Koichiro Uto, Mitsuhiro Ebara, Stefania Pagliari, Giancarlo Forte and Takao Aoyagi

    2012-01-01

    Full Text Available The acknowledged ability of synthetic materials to induce cell-specific responses regardless of biological supplies provides tissue engineers with the opportunity to find the appropriate materials and conditions to prepare tissue-targeted scaffolds. Stem and mature cells have been shown to acquire distinct morphologies in vitro and to modify their phenotype when grown on synthetic materials with tunable mechanical properties. The stiffness of the substrate used for cell culture is likely to provide cells with mechanical cues mimicking given physiological or pathological conditions, thus affecting the biological properties of cells. The sensitivity of cells to substrate composition and mechanical properties resides in multiprotein complexes called focal adhesions, whose dynamic modification leads to cytoskeleton remodeling and changes in gene expression. In this study, the remodeling of focal adhesions in human mesenchymal stem cells in response to substrate stiffness was followed in the first phases of cell–matrix interaction, using poly-ε-caprolactone planar films with similar chemical composition and different elasticity. As compared to mature dermal fibroblasts, mesenchymal stem cells showed a specific response to substrate stiffness, in terms of adhesion, as a result of differential focal adhesion assembly, while their multipotency as a bulk was not significantly affected by matrix compliance. Given the sensitivity of stem cells to matrix mechanics, the mechanobiology of such cells requires further investigations before preparing tissue-specific scaffolds.

  20. Corneal cell adhesion to contact lens hydrogel materials enhanced via tear film protein deposition.

    Directory of Open Access Journals (Sweden)

    Claire M Elkins

    Full Text Available Tear film protein deposition on contact lens hydrogels has been well characterized from the perspective of bacterial adhesion and viability. However, the effect of protein deposition on lens interactions with the corneal epithelium remains largely unexplored. The current study employs a live cell rheometer to quantify human corneal epithelial cell adhesion to soft contact lenses fouled with the tear film protein lysozyme. PureVision balafilcon A and AirOptix lotrafilcon B lenses were soaked for five days in either phosphate buffered saline (PBS, borate buffered saline (BBS, or Sensitive Eyes Plus Saline Solution (Sensitive Eyes, either pure or in the presence of lysozyme. Treated contact lenses were then contacted to a live monolayer of corneal epithelial cells for two hours, after which the contact lens was sheared laterally. The apparent cell monolayer relaxation modulus was then used to quantify the extent of cell adhesion to the contact lens surface. For both lens types, lysozyme increased corneal cell adhesion to the contact lens, with the apparent cell monolayer relaxation modulus increasing up to an order of magnitude in the presence of protein. The magnitude of this increase depended on the identity of the soaking solution: lenses soaked in borate-buffered solutions (BBS, Sensitive Eyes exhibited a much greater increase in cell attachment upon protein addition than those soaked in PBS. Significantly, all measurements were conducted while subjecting the cells to moderate surface pressures and shear rates, similar to those experienced by corneal cells in vivo.

  1. Conjugates of Cell Adhesion Peptides for Therapeutics and Diagnostics Against Cancer and Autoimmune Diseases.

    Science.gov (United States)

    Moral, Mario E G; Siahaan, Teruna J

    2017-01-01

    Overexpressed cell-surface receptors are hallmarks of many disease states and are often used as markers for targeting diseased cells over healthy counterparts. Cell adhesion peptides, which are often derived from interacting regions of these receptor-ligand proteins, mimic surfaces of intact proteins and, thus, have been studied as targeting agents for various payloads to certain cell targets for cancers and autoimmune diseases. Because many cytotoxic agents in the free form are often harmful to healthy cells, the use of cell adhesion peptides in targeting their delivery to diseased cells has been studied to potentially reduce required effective doses and associated harmful side-effects. In this review, multiple cell adhesion peptides from extracellular matrix and ICAM proteins were used to selectively direct drug payloads, signal-inhibitor peptides, and diagnostic molecules, to diseased cells over normal counterparts. RGD constructs have been used to improve the selectivity and efficacy of diagnostic and drug-peptide conjugates against cancer cells. From this precedent, novel conjugates of antigenic and cell adhesion peptides, called Bifunctional Peptide Inhibitors (BPIs), have been designed to selectively regulate immune cells and suppress harmful inflammatory responses in autoimmune diseases. Similar peptide conjugations with imaging agents have delivered promising diagnostic methods in animal models of rheumatoid arthritis. BPIs have also been shown to generate immune tolerance and suppress autoimmune diseases in animal models of type-1 diabetes, rheumatoid arthritis, and multiple sclerosis. Collectively, these studies show the potential of cell adhesion peptides in improving the delivery of drugs and diagnostic agents to diseased cells in clinical settings. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  2. Early cell adhesion events differ between osteoporotic and non-osteoporotic osteoblasts.

    Science.gov (United States)

    Perinpanayagam, H; Zaharias, R; Stanford, C; Brand, R; Keller, J; Schneider, G

    2001-11-01

    In osteoporosis, the regenerative capacity of bone is compromised, which may involve altered osteoblast (OB) activity. This could be attributed to an inappropriate synthesis and assembly of an extracellular matrix (ECM), altered cell adhesion to the ECM, or be due to inappropriate downstream activation of adhesion-mediated signaling cascades through proteins such as focal adhesion kinase (FAK). The purpose of our study was to compare early adhesion-mediated events using previously described and characterized clinically derived OBs obtained from human patients undergoing major joint arthroplasty for osteoporosis or osteoarthritis. The presence or absence of osteoporosis was established with a radiographic index. Using light microscopy and crystal violet staining, we show that OB cells derived from sites of osteoporosis do not attach and spread as well as non-osteoporotic (OP) OB cells. OP cells initially have a more rounded morphology, and show significantly less (P attachment to serum-coated tissue culture plastic over a 24 h time period. Immunofluorescent labeling after 24 h of attachment showed that OP OB focal adhesions (FAs) and stress fibers were less defined, and that the OP cells were smaller and had a more motile phenotype. When normalized protein lysates were Western blotted for phosphotyrosine (PY) a band corresponding to pp125FAK was identified. FAK tyrosine phosphorylation was evident at 6 h in both the OP and non-OP OBs, but decreased or was absent through 24 h in OP OBs. These results suggest early adhesion-mediated events, such as cell adhesion, attachment, and FAK signaling via PY may be altered in OP OBs.

  3. Photocrosslinked nanocomposite hydrogels from PEG and silica nanospheres: Structural, mechanical and cell adhesion characteristics

    International Nuclear Information System (INIS)

    Gaharwar, Akhilesh K.; Rivera, Christian; Wu, Chia-Jung; Chan, Burke K.; Schmidt, Gudrun

    2013-01-01

    Photopolymerized hydrogels are extensively investigated for various tissue engineering applications, primarily due to their ability to form hydrogels in a minimally invasive manner. Although photocrosslinkable hydrogels provide necessary biological and chemical characteristics to mimic cellular microenvironments, they often lack sufficient mechanical properties. Recently, nanocomposite approaches have demonstrated potential to overcome these deficits by reinforcing the hydrogel network with. In this study, we investigate some physical, chemical, and biological properties of photocrosslinked poly(ethylene glycol) (PEG)-silica hydrogels. The addition of silica nanospheres significantly suppresses the hydration degree of the PEG hydrogels, indicating surface interactions between the silica nanospheres and the polymer chains. No significant change in hydrogel microstructure or average pore size due to the addition of silica nanospheres was observed. However, addition of silica nanospheres significantly increases both the mechanical strength and the toughness of the hydrogel networks. The biological properties of these nanocomposite hydrogels were evaluated by seeding fibroblast cells on the hydrogel surface. While the PEG hydrogels showed minimum cell adhesion, spreading and proliferation, the addition of silica nanospheres enhanced initial cell adhesion, promoted cell spreading and increased the metabolic activity of the cells. Overall, results indicate that the addition of silica nanospheres improves the mechanical stiffness and cell adhesion properties of PEG hydrogels and can be used for biomedical applications that required controlled cell adhesion. - Graphical abstract: Structural, mechanical and biological properties of photocrosslinked nanocomposite hydrogels from silica and poly(ethylene oxide) are investigated. Silica reinforce the hydrogel network and improved mechanical strength. Addition of induces cell adhesion characteristic properties for various

  4. Quantal concept of T-cell activation: adhesion domains as immunological synapses

    International Nuclear Information System (INIS)

    Sackmann, Erich

    2011-01-01

    Adhesion micro-domains (ADs) formed during encounters of lymphocytes with antigen-presenting cells (APC) mediate the genetic expression of quanta of cytokines interleukin-2 (IL-2). The IL-2-induced activation of IL-2 receptors promotes the stepwise progression of the T-cells through the cell cycle, hence their name, immunological synapses. The ADs form short-lived reaction centres controlling the recruitment of activators of the biochemical pathway (the kinases Lck and ZAP) while preventing the access of inhibitors (phosphatase CD45) through steric repulsion forces. CD45 acts as the generator of adhesion domains and, through its role as a spacer protein, also as the promoter of the reaction. In a second phase of T-cell-APC encounters, long-lived global reaction spaces (called supramolecular activation complexes (SMAC)) form by talin-mediated binding of the T-cell integrin (LFA-1) to the counter-receptor ICAM-1, resulting in the formation of ring-like tight adhesion zones (peripheral SMAC). The ADs move to the centre of the intercellular adhesion zone forming the central SMAC, which serve in the recycling of the AD. We propose that cell stimulation is triggered by integrating the effect evoked by the short-lived adhesion domains. Similar global reaction platforms are formed by killer cells to destruct APC. We present a testable mechanical model showing that global reaction spaces (SMAC or dome-like contacts between cytotoxic cells and APC) form by self-organization through delayed activation of the integrin-binding affinity and stabilization of the adhesion zones by F-actin recruitment. The mechanical stability and the polarization of the adhering T-cells are mediated by microtubule-actin cross-talk.

  5. Enhanced adhesion of early endothelial progenitor cells to radiation-induced senescence-like vascular endothelial cells in vitro

    International Nuclear Information System (INIS)

    Sermsathanasawadi, N.; Inoue, Yoshinori; Iwai, Takehisa; Ishii, Hideto; Yoshida, Masayuki; Igarashi, Kaori; Miura, Masahiko

    2009-01-01

    The effects of ionizing radiation (IR) on tumor neovascularization are still unclear. We previously reported that vascular endothelial cells (ECs) expressing the IR-induced senescence-like (IRSL) phenotype exhibit a significant decrease in angiogenic activity in vitro. In this study, we examined the effects of the IRSL phenotype on adhesion to early endothelial progenitor cells (early EPCs). Adhesion of human peripheral blood-derived early EPCs to human umbilical vein endothelial cells (HUVECs) expressing the IRSL phenotype was evaluated by an adhesion assay under static conditions. It was revealed that the IRSL HUVECs supported significantly more adhesion of early EPCs than normal HUVECs. Expressions of ICAM-1, VCAM-1 and E-selectin were up-regulated in IRSL HUVECs. Pre-treatment of IRSL HUVECs with adhesion-blocking monoclonal antibodies against E-selectin and VCAM-1 significantly reduced early EPC adhesion to IRSL HUVECs, suggesting a potential role for the E-selectin and VCAM-1 in the adhesion between IRSL ECs and early EPCs. Therefore, the IRSL phenotype expressed in ECs may enhance neovascularization via increased homing of early EPCs. Our findings are first to implicate the complex effects of this phenotype on tumor neovascularization following irradiation. (author)

  6. Cell adhesion of F{sup +} ion implantation of intraocular lens

    Energy Technology Data Exchange (ETDEWEB)

    Li, D.J. E-mail: dejunli@hotmail.com; Cui, F.Z.; Gu, H.Q

    1999-04-01

    The cell adhesion of ion implanted polymethylmethacrylate (PMMA) intraocular lens was studied using cultured cells in vitro. F{sup +} ion implantation was performed at the energies of 40, 60, 80, 100 keV with the fluences ranging from 5x10{sup 13} to 1x10{sup 15} ions/cm{sup 2} at room temperature. The cell adhesion tests gave interesting results that the number of the neutral granulocytes and the macrophages adhering on surface were reduced significantly after ion implantation. The optimal fluence was about 4x10{sup 14} ions/cm{sup 2}. The hydrophobicity imparted to the lens surface was also enhanced. The results of X-ray photoelectron spectroscopy analysis indicated that ion implantation resulted in the cleavage of some pendant groups, the oxidation of the surface, and the formation of some new chemical bonds, which was probably the main reason for the cell adhesion change.

  7. Cell adhesion and EGFR activation regulate EphA2 expression in cancer

    DEFF Research Database (Denmark)

    Larsen, Alice Bjerregaard; Stockhausen, Marie-Thérése; Poulsen, Hans Skovgaard

    2010-01-01

    family kinases (SRC). Moreover, the results show that adhesion-induced EGFR activation and EphA2 expression is affected by interactions with extracellular matrix (ECM) proteins working as integrin ligands. Stimulation with the EphA2 ligand, ephrinA1 inhibited ERK phosphorylation and cancer cell viability...... largely unknown. Here we show that the expression of EphA2 in in vitro cultured cells, is restricted to cells growing adherently and that adhesion-induced EphA2 expression is dependent upon activation of the epidermal growth factor receptor (EGFR), mitogen activated protein kinase kinase (MEK) and Src...

  8. Smooth muscle cell rigidity and extracellular matrix organization influence endothelial cell spreading and adhesion formation in coculture.

    Science.gov (United States)

    Wallace, Charles S; Strike, Sophie A; Truskey, George A

    2007-09-01

    Efforts to develop functional tissue-engineered blood vessels have focused on improving the strength and mechanical properties of the vessel wall, while the functional status of the endothelium within these vessels has received less attention. Endothelial cell (EC) function is influenced by interactions between its basal surface and the underlying extracellular matrix. In this study, we utilized a coculture model of a tissue-engineered blood vessel to evaluate EC attachment, spreading, and adhesion formation to the extracellular matrix on the surface of quiescent smooth muscle cells (SMCs). ECs attached to and spread on SMCs primarily through the alpha(5)beta(1)-integrin complex, whereas ECs used either alpha(5)beta(1)- or alpha(v)beta(3)-integrin to spread on fibronectin (FN) adsorbed to plastic. ECs in coculture lacked focal adhesions, but EC alpha(5)beta(1)-integrin bound to fibrillar FN on the SMC surface, promoting rapid fibrillar adhesion formation. As assessed by both Western blot analysis and quantitative real-time RT-PCR, coculture suppressed the expression of focal adhesion proteins and mRNA, whereas tensin protein and mRNA expression were elevated. When attached to polyacrylamide gels with similar elastic moduli as SMCs, focal adhesion formation and the rate of cell spreading increased relative to ECs in coculture. Thus, the elastic properties are only one factor contributing to EC spreading and focal adhesion formation in coculture. The results suggest that the softness of the SMCs and the fibrillar organization of FN inhibit focal adhesions and reduce cell spreading while promoting fibrillar adhesion formation. These changes in the type of adhesions may alter EC signaling pathways in tissue-engineered blood vessels.

  9. Hyaluronan synthase 3 (HAS3) overexpression downregulates MV3 melanoma cell proliferation, migration and adhesion

    International Nuclear Information System (INIS)

    Takabe, Piia; Bart, Geneviève; Ropponen, Antti; Rilla, Kirsi; Tammi, Markku; Tammi, Raija; Pasonen-Seppänen, Sanna

    2015-01-01

    Malignant skin melanoma is one of the most deadly human cancers. Extracellular matrix (ECM) influences the growth of malignant tumors by modulating tumor cells adhesion and migration. Hyaluronan is an essential component of the ECM, and its amount is altered in many tumors, suggesting an important role for hyaluronan in tumorigenesis. Nonetheless its role in melanomagenesis is not understood. In this study we produced a MV3 melanoma cell line with inducible expression of the hyaluronan synthase 3 (HAS3) and studied its effect on the behavior of the melanoma cells. HAS3 overexpression expanded the cell surface hyaluronan coat and decreased melanoma cell adhesion, migration and proliferation by cell cycle arrest at G1/G0. Melanoma cell migration was restored by removal of cell surface hyaluronan by Streptomyces hyaluronidase and by receptor blocking with hyaluronan oligosaccharides, while the effect on cell proliferation was receptor independent. Overexpression of HAS3 decreased ERK1/2 phosphorylation suggesting that inhibition of MAP-kinase signaling was responsible for these suppressive effects on the malignant phenotype of MV3 melanoma cells. - Highlights: • Inducible HAS3-MV3 melanoma cell line was generated using Lentiviral transduction. • HAS3 overexpression inhibits MV3 cell migration via hyaluronan–receptor interaction. • HAS3 overexpression decreases MV3 melanoma cell proliferation and adhesion. • ERK1/2 phosphorylation is downregulated by 50% in HAS3 overexpressing cells. • The results suggest that hyaluronan has anti-cancer like effects in melanoma

  10. Hyaluronan synthase 3 (HAS3) overexpression downregulates MV3 melanoma cell proliferation, migration and adhesion

    Energy Technology Data Exchange (ETDEWEB)

    Takabe, Piia, E-mail: piia.takabe@uef.fi [University of Eastern Finland, Institute of Biomedicine, 70211 Kuopio (Finland); Bart, Geneviève [University of Eastern Finland, Institute of Biomedicine, 70211 Kuopio (Finland); Ropponen, Antti [University of Eastern Finland, Institute of Clinical Medicine, 70211 Kuopio (Finland); Rilla, Kirsi; Tammi, Markku; Tammi, Raija; Pasonen-Seppänen, Sanna [University of Eastern Finland, Institute of Biomedicine, 70211 Kuopio (Finland)

    2015-09-10

    Malignant skin melanoma is one of the most deadly human cancers. Extracellular matrix (ECM) influences the growth of malignant tumors by modulating tumor cells adhesion and migration. Hyaluronan is an essential component of the ECM, and its amount is altered in many tumors, suggesting an important role for hyaluronan in tumorigenesis. Nonetheless its role in melanomagenesis is not understood. In this study we produced a MV3 melanoma cell line with inducible expression of the hyaluronan synthase 3 (HAS3) and studied its effect on the behavior of the melanoma cells. HAS3 overexpression expanded the cell surface hyaluronan coat and decreased melanoma cell adhesion, migration and proliferation by cell cycle arrest at G1/G0. Melanoma cell migration was restored by removal of cell surface hyaluronan by Streptomyces hyaluronidase and by receptor blocking with hyaluronan oligosaccharides, while the effect on cell proliferation was receptor independent. Overexpression of HAS3 decreased ERK1/2 phosphorylation suggesting that inhibition of MAP-kinase signaling was responsible for these suppressive effects on the malignant phenotype of MV3 melanoma cells. - Highlights: • Inducible HAS3-MV3 melanoma cell line was generated using Lentiviral transduction. • HAS3 overexpression inhibits MV3 cell migration via hyaluronan–receptor interaction. • HAS3 overexpression decreases MV3 melanoma cell proliferation and adhesion. • ERK1/2 phosphorylation is downregulated by 50% in HAS3 overexpressing cells. • The results suggest that hyaluronan has anti-cancer like effects in melanoma.

  11. Cell Adhesion Molecule and Lymphocyte Activation Marker Expression during Experimental Vaginal Candidiasis

    Science.gov (United States)

    Wormley, Floyd L.; Chaiban, Joseph; Fidel, Paul L.

    2001-01-01

    Cell-mediated immunity by Th1-type CD4+ T cells is the predominant host defense mechanism against mucosal candidiasis. However, studies using an estrogen-dependent murine model of vaginal candidiasis have demonstrated little to no change in resident vaginal T cells during infection and no systemic T-cell infiltration despite the presence of Candida-specific systemic Th1-type responses in infected mice. The present study was designed to further investigate these observations by characterizing T-cell activation and cell adhesion molecule expression during primary and secondary C. albicans vaginal infections. While flow cytometry analysis of activation markers showed some evidence for activation of CD3+ draining lymph node and/or vaginal lymphocytes during both primary and secondary vaginal Candida infection, CD3+ cells expressing the homing receptors and integrins α4β7, αM290β7, and α4β1 in draining lymph nodes of mice with primary and secondary infections were reduced compared to results for uninfected mice. At the local level, few vaginal lymphocytes expressed integrins, with only minor changes observed during both primary and secondary infections. On the other hand, immunohistochemical analysis of vaginal cell adhesion molecule expression showed increases in mucosal addressin cell adhesion molecule 1 and vascular cell adhesion molecule 1 expression during both primary and secondary infections. Altogether, these data suggest that although the vaginal tissue is permissive to cellular infiltration during a vaginal Candida infection, the reduced numbers of systemic cells expressing the reciprocal cellular adhesion molecules may preempt cellular infiltration, thereby limiting Candida-specific T-cell responses against infection. PMID:11447188

  12. Involvement of JAK2 upstream of the PI 3-kinase in cell-cell adhesion regulation by gastrin

    International Nuclear Information System (INIS)

    Ferrand, Audrey; Kowalski-Chauvel, Aline; Bertrand, Claudine; Pradayrol, Lucien; Fourmy, Daniel; Dufresne, Marlene; Seva, Catherine

    2004-01-01

    The Janus kinase/signal transducers and activators of transcription (JAK/STAT) signaling pathway has been implicated in cell transformation and proliferation. Besides aberrant cell proliferation, loss of cell-cell adhesion during epithelial-mesenchymal transition (EMT) is an important event which occurs during development of epithelial cancers. However, the role of JAK-dependent pathways in this process is not known. We analyzed the involvement of these pathways in the regulation of E-cadherin-dependent cell-cell adhesion by gastrin, a mitogenic factor for gastrointestinal (GI) tract. We identified JAK2/STAT3 as a new pathway in gastrin signaling. We demonstrated that JAK2 functions as an upstream mediator of the phosphatidylinositol 3 (PI 3)-kinase activity in gastrin signaling. Indeed, we observed a coprecipitation of both kinases and an inhibition of gastrin-induced PI 3-kinase activation when JAK2 activity is blocked. We also demonstrated that loss of cell-cell adhesion and the increase in cell motility induced by gastrin required the activation of JAK2 and the PI 3-kinase. Indeed, the modifications in localization of adherens junctions proteins and the migration, observed in gastrin-stimulated cells, were reversed by inhibition of both kinases. These results described the involvement of JAK2 in the modulation of cell-cell adhesion in epithelial cells. They support a possible role of JAK2 in the epithelial-mesenchymal transition which occurs during malignant development

  13. Fermented soya bean (tempe) extracts reduce adhesion of enterotoxigenic Escherichia coli to intestinal epithelial cells

    NARCIS (Netherlands)

    Roubos-van den Hil, P.J.; Nout, M.J.R.; Beumer, R.R.; Meulen, van der J.; Zwietering, M.H.

    2009-01-01

    Aims: This study aimed to investigate the effect of processed soya bean, during the successive stages of tempe fermentation and different fermentation times, on adhesion of enterotoxigenic Escherichia coli (ETEC) K88 to intestinal brush border cells as well as Caco-2 intestinal epithelial cells; and

  14. Corrugated round fibers to improve cell adhesion and proliferation in tissue engineering scaffolds

    NARCIS (Netherlands)

    Bettahalli Narasimha, M.S.; Arkesteijn, I.T.M.; Wessling, Matthias; Poot, Andreas A.; Stamatialis, Dimitrios

    2013-01-01

    Optimal cell interaction with biomaterial scaffolds is one of the important requirements for the development of successful in vitro tissue-engineered tissues. Fast, efficient and spatially uniform cell adhesion can improve the clinical potential of engineered tissue. Three-dimensional (3-D) solid

  15. Cancer Cell Adhesion and Metastasis: Selectins, Integrins, and the Inhibitory Potential of Heparins

    Directory of Open Access Journals (Sweden)

    Gerd Bendas

    2012-01-01

    Full Text Available Cell adhesion molecules play a significant role in cancer progression and metastasis. Cell-cell interactions of cancer cells with endothelium determine the metastatic spread. In addition, direct tumor cell interactions with platelets, leukocytes, and soluble components significantly contribute to cancer cell adhesion, extravasation, and the establishment of metastatic lesions. Clinical evidence indicates that heparin, commonly used for treatment of thromboembolic events in cancer patients, is beneficial for their survival. Preclinical studies confirm that heparin possesses antimetastatic activities that lead to attenuation of metastasis in various animal models. Heparin contains several biological activities that may affect several steps in metastatic cascade. Here we focus on the role of cellular adhesion receptors in the metastatic cascade and discuss evidence for heparin as an inhibitor of cell adhesion. While P- and L-selectin facilitation of cellular contacts during hematogenous metastasis is being accepted as a potential target of heparin, here we propose that heparin may also interfere with integrin activity and thereby affect cancer progression. This review summarizes recent findings about potential mechanisms of tumor cell interactions in the vasculature and antimetastatic activities of heparin.

  16. Mechanical Entrapment Is Insufficient and Intercellular Adhesion Is Essential for Metastatic Cell Arrest in Distant Organs

    Directory of Open Access Journals (Sweden)

    Olga V. Glinskii

    2005-05-01

    Full Text Available In this report, we challenge a common perception that tumor embolism is a size-limited event of mechanical arrest, occurring in the first capillary bed encountered by blood-borne metastatic cells. We tested the hypothesis that mechanical entrapment alone, in the absence of tumor cell adhesion to blood vessel walls, is not sufficient for metastatic cell arrest in target organ microvasculature. The in vivo metastatic deposit formation assay was used to assess the number and location of fluorescently labeled tumor cells lodged in selected organs and tissues following intravenous inoculation. We report that a significant fraction of breast and prostate cancer cells escapes arrest in a lung capillary bed and lodges successfully in other organs and tissues. Monoclonal antibodies and carbohydrate-based compounds (anti-Thomsen-Friedenreich antigen antibody, anti-galectin-3 antibody, modified citrus pectin, and lactulosyl-L-leucine, targeting specifically β-galactoside-mediated tumor-endothelial cell adhesive interactions, inhibited by >90% the in vivo formation of breast and prostate carcinoma metastatic deposits in mouse lung and bones. Our results indicate that metastatic cell arrest in target organ microvessels is not a consequence of mechanical trapping, but is supported predominantly by intercellular adhesive interactions mediated by cancer-associated Thomsen-Friedenreich glycoantigen and β-galactoside-binding lectin galectin-3. Efficient blocking of β-galactoside-mediated adhesion precludes malignant cell lodging in target organs.

  17. QUANTIFICATION OF GLOMERULAR EPITHELIAL-CELL ADHESION BY USING ANTI-DNA ANTIBODIES IN ELISA

    NARCIS (Netherlands)

    COERS, W; SMEENK, RJT; SALANT, DJ; WEENING, JJ

    A sensitive and reproducible microassay is described for quantification of adhesion of cells to matrix-coated 96-wells plates under different experimental conditions. For this purpose glomerular visceral epithelial cells (GVEC) were used. Attached GVEC were fixed with methanol and incubated with a

  18. Induction of gastric cancer cell adhesion through transforming growth factor-beta1-mediated peritoneal fibrosis

    Directory of Open Access Journals (Sweden)

    Ma Xiao-Yang

    2010-10-01

    Full Text Available Abstract Background Peritoneal dissemination is one of the main causes of death in gastric cancer patients. Transforming growth factor-beta1 (TGF-β1, one of the most potent fibrotic stimuli for mesothelial cells, may play a key role in this processing. The purpose of this study is to elucidate the effects of TGF-β1 on regulation of gastric cancer adhesion to mesothelial cells. Methods Peritoneal tissues and peritoneal wash fluid were obtained for hematoxylin and eosin staining or ELISA to measure fibrosis and TGF-β1 levels, respectively. The peritoneal mesothelial cell line, HMrSV5, was used to determine the role of TGF-β1 in regulation of gastric cancer cell adhesion to mesothelial cells and expression of collagen, fibronectin, and Smad 2/3 by using adhesion assay, western blot, and RT-PCR. Results The data showed that TGF-β1 treatment was able to induce collagen III and fibronectin expression in the mesothelial cells, which was associated with an increased adhesion ability of gastric cancer cells, but knockdown of minimal sites of cell binding domain of extracellular matrix can partially inhibit these effects. Conclusion Peritoneal fibrosis induced by TGF-β1 may provide a favorable environment for the dissemination of gastric cancer.

  19. An evidence for adhesion-mediated acquisition of acute myeloid leukemic stem cell-like immaturities

    International Nuclear Information System (INIS)

    Funayama, Keiji; Shimane, Miyuki; Nomura, Hitoshi; Asano, Shigetaka

    2010-01-01

    For long-term survival in vitro and in vivo of acute myeloid leukemia cells, their adhesion to bone marrow stromal cells is indispensable. However, it is still unknown if these events are uniquely induced by the leukemic stem cells. Here we show that TF-1 human leukemia cells, once they have formed a cobblestone area by adhering to mouse bone marrow-derived MS-5 cells, can acquire some leukemic stem cell like properties in association with a change in the CD44 isoform-expression pattern and with an increase in a set of related microRNAs. These findings strongly suggest that at least some leukemia cells can acquire leukemic stem cell like properties in an adhesion-mediated stochastic fashion.

  20. Adhesion and Proliferation of Human Periodontal Ligament Cells on Poly(2-methoxyethyl acrylate

    Directory of Open Access Journals (Sweden)

    Erika Kitakami

    2014-01-01

    Full Text Available Human periodontal ligament (PDL cells obtained from extracted teeth are a potential cell source for tissue engineering. We previously reported that poly(2-methoxyethyl acrylate (PMEA is highly biocompatible with human blood cells. In this study, we investigated the adhesion, morphology, and proliferation of PDL cells on PMEA and other types of polymers to design an appropriate scaffold for tissue engineering. PDL cells adhered and proliferated on all investigated polymer surfaces except for poly(2-hydroxyethyl methacrylate and poly[(2-methacryloyloxyethyl phosphorylcholine-co-(n-butyl methacrylate]. The initial adhesion of the PDL cells on PMEA was comparable with that on polyethylene terephthalate (PET. In addition, the PDL cells on PMEA spread well and exhibited proliferation behavior similar to that observed on PET. In contrast, platelets hardly adhered to PMEA. PMEA is therefore expected to be an excellent scaffold for tissue engineering and for culturing tissue-derived cells in a blood-rich environment.

  1. An evidence for adhesion-mediated acquisition of acute myeloid leukemic stem cell-like immaturities

    Energy Technology Data Exchange (ETDEWEB)

    Funayama, Keiji; Shimane, Miyuki; Nomura, Hitoshi [Department of Integrative Bioscience and Biomedical Engineering, Waseda University, 4-3-1 Ohkubo, Shinjuku-ku, Tokyo 169-8555 (Japan); Asano, Shigetaka, E-mail: asgtkmd@waseda.jp [Department of Integrative Bioscience and Biomedical Engineering, Waseda University, 4-3-1 Ohkubo, Shinjuku-ku, Tokyo 169-8555 (Japan)

    2010-02-12

    For long-term survival in vitro and in vivo of acute myeloid leukemia cells, their adhesion to bone marrow stromal cells is indispensable. However, it is still unknown if these events are uniquely induced by the leukemic stem cells. Here we show that TF-1 human leukemia cells, once they have formed a cobblestone area by adhering to mouse bone marrow-derived MS-5 cells, can acquire some leukemic stem cell like properties in association with a change in the CD44 isoform-expression pattern and with an increase in a set of related microRNAs. These findings strongly suggest that at least some leukemia cells can acquire leukemic stem cell like properties in an adhesion-mediated stochastic fashion.

  2. Fetuin-A associates with histones intracellularly and shuttles them to exosomes to promote focal adhesion assembly resulting in rapid adhesion and spreading in breast carcinoma cells.

    Science.gov (United States)

    Nangami, Gladys; Koumangoye, Rainelli; Shawn Goodwin, J; Sakwe, Amos M; Marshall, Dana; Higginbotham, James; Ochieng, Josiah

    2014-11-01

    The present analyses were undertaken to define the mechanisms by which fetuin-A modulates cellular adhesion. FLAG-tagged fetuin-A was expressed in breast carcinoma and HEK-293T cells. We demonstrated by confocal microscopy that fetuin-A co-localizes with histone H2A in the cell nucleus, forms stable complexes with histones such as H2A and H3 in solution, and shuttles histones to exosomes. The rate of cellular adhesion and spreading to either fibronectin or laminin coated wells was accelerated significantly in the presence of either endogenous fetuin-A or serum derived protein. More importantly, the formation of focal adhesion complexes on surfaces coated by laminin or fibronectin was accelerated in the presence of fetuin-A or histone coated exosomes. Cellular adhesion mediated by histone coated exosomes was abrogated by heparin and heparinase III. Heparinase III cleaves heparan sulfate from cell surface heparan sulfate proteoglycans. Lastly, the uptake of histone coated exosomes and subsequent cellular adhesion, was abrogated by heparin. Taken together, the data suggest a mechanism where fetuin-A, either endogenously synthesized or supplied extracellularly can extract histones from the nucleus or elsewhere in the cytosol/membrane and load them on cellular exosomes which then mediate adhesion by interacting with cell surface heparan sulfate proteoglycans via bound histones. Copyright © 2014 Elsevier Inc. All rights reserved.

  3. High expression of carcinoembryonic antigen-related cell adhesion molecule (CEACAM) 6 and 8 in primary myelofibrosis

    DEFF Research Database (Denmark)

    Riley, Caroline Hasselbalch; Skov, Vibe; Larsen, Thomas Stauffer

    2011-01-01

    for the egress of CD34+ cells from the bone marrow. Carcinoembryonic antigen-related cell adhesion molecule (CEACAM) 6 has been implicated in cell adhesion, cellular invasiveness, angiogenesis, and inflammation, which are all key processes in the pathophysiology of PMF. Accordingly, CEACAMs may play an important...

  4. In vitro effects of ATG-Fresenius on immune cell adhesion.

    Science.gov (United States)

    Kanzler, I; Seitz-Merwald, I; Schleger, S; Kaczmarek, I; Kur, F; Beiras-Fernandez, A

    2013-06-01

    ATG-Fresenius, a purified rabbit polyclonal anti-human T-lymphocyte immunoglobulin is used for induction immunosuppression as well as prevention and treatment of acute rejection episodes among patients receiving solid organ transplants. The aim of this study was to investigate the in vitro activity of ATG-Fresenius upon immune cell adhesion, which may explain its activity to mitigate ischemia-reperfusion injury. Human vascular endothelial cells (HUVEC) and peripheral blood mononuclear cells (PBMCs) isolated from umbilical vein or peripheral blood were incubated 20 to 24 hours before analysis. HUVEC were incubated with 10 and 100 μg/mL ATG-Fresenius or reference polyclonal rabbit immunoglobulin G. Analysis of immune cell adhesion to endothelial cells was studied in cocultures of PBMCs and adherent HUVEC. Endothelial cell expression of adhesion molecules CD62E and CD54 was determined by flow cytometry. The numbers of T-, B- and natural killer cells attached to HUVEC were also determined by flow cytometry. Groups were compared using one-way analysis of variance. We showed that ATG-Fresenius binds to endothelial cells particularly activated ones expressing increased levels of E-selectin and ICAM-1. The increased binding of ATG-Fresenius to activated endothelial cells was consistent with its known binding to Intercellular Adhesion Molecule 1 (ICAM-1) and selectins. We also showed that ATG-Fresenius inhibited adhesion of prestimulated immune cells to activated endothelium. We demonstrated dose-dependent binding of ATG-Fresenius to activated endothelial cells. Copyright © 2013 Elsevier Inc. All rights reserved.

  5. Intercellular adhesion molecule-1 expression by skeletal muscle cells augments myogenesis

    International Nuclear Information System (INIS)

    Goh, Qingnian; Dearth, Christopher L.; Corbett, Jacob T.; Pierre, Philippe; Chadee, Deborah N.; Pizza, Francis X.

    2015-01-01

    We previously demonstrated that the expression of intercellular adhesion molecule-1 (ICAM-1) by skeletal muscle cells after muscle overload contributes to ensuing regenerative and hypertrophic processes in skeletal muscle. The objective of the present study is to reveal mechanisms through which skeletal muscle cell expression of ICAM-1 augments regenerative and hypertrophic processes of myogenesis. This was accomplished by genetically engineering C2C12 myoblasts to stably express ICAM-1, and by inhibiting the adhesive and signaling functions of ICAM-1 through the use of a neutralizing antibody or cell penetrating peptide, respectively. Expression of ICAM-1 by cultured skeletal muscle cells augmented myoblast–myoblast adhesion, myotube formation, myonuclear number, myotube alignment, myotube–myotube fusion, and myotube size without influencing the ability of myoblasts to proliferate or differentiate. ICAM-1 augmented myotube formation, myonuclear accretion, and myotube alignment through a mechanism involving adhesion-induced activation of ICAM-1 signaling, as these dependent measures were reduced via antibody and peptide inhibition of ICAM-1. The adhesive and signaling functions of ICAM-1 also facilitated myotube hypertrophy through a mechanism involving myotube–myotube fusion, protein synthesis, and Akt/p70s6k signaling. Our findings demonstrate that ICAM-1 expression by skeletal muscle cells augments myogenesis, and establish a novel mechanism through which the inflammatory response facilitates growth processes in skeletal muscle. - Highlights: • We examined mechanisms through which skeletal muscle cell expression of ICAM-1 facilitates events of in vitro myogenesis. • Expression of ICAM-1 by cultured myoblasts did not influence their ability to proliferate or differentiate. • Skeletal muscle cell expression of ICAM-1 augmented myoblast fusion, myotube alignment, myotube–myotube fusion, and myotube size. • ICAM-1 augmented myogenic processes through

  6. Intercellular adhesion molecule-1 expression by skeletal muscle cells augments myogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Goh, Qingnian; Dearth, Christopher L.; Corbett, Jacob T. [Department of Kinesiology, The University of Toledo, Toledo, OH (United States); Pierre, Philippe [Centre d’Immunologie de Marseille-Luminy U2M, Aix-Marseille Université, Marseille (France); INSERM U631, Institut National de la Santé et Recherche Médicale, Marseille (France); CNRS UMR6102, Centre National de la Recherche Scientifique, Marseille (France); Chadee, Deborah N. [Department of Biological Sciences, The University of Toledo, Toledo, OH (United States); Pizza, Francis X., E-mail: Francis.Pizza@utoledo.edu [Department of Kinesiology, The University of Toledo, Toledo, OH (United States)

    2015-02-15

    We previously demonstrated that the expression of intercellular adhesion molecule-1 (ICAM-1) by skeletal muscle cells after muscle overload contributes to ensuing regenerative and hypertrophic processes in skeletal muscle. The objective of the present study is to reveal mechanisms through which skeletal muscle cell expression of ICAM-1 augments regenerative and hypertrophic processes of myogenesis. This was accomplished by genetically engineering C2C12 myoblasts to stably express ICAM-1, and by inhibiting the adhesive and signaling functions of ICAM-1 through the use of a neutralizing antibody or cell penetrating peptide, respectively. Expression of ICAM-1 by cultured skeletal muscle cells augmented myoblast–myoblast adhesion, myotube formation, myonuclear number, myotube alignment, myotube–myotube fusion, and myotube size without influencing the ability of myoblasts to proliferate or differentiate. ICAM-1 augmented myotube formation, myonuclear accretion, and myotube alignment through a mechanism involving adhesion-induced activation of ICAM-1 signaling, as these dependent measures were reduced via antibody and peptide inhibition of ICAM-1. The adhesive and signaling functions of ICAM-1 also facilitated myotube hypertrophy through a mechanism involving myotube–myotube fusion, protein synthesis, and Akt/p70s6k signaling. Our findings demonstrate that ICAM-1 expression by skeletal muscle cells augments myogenesis, and establish a novel mechanism through which the inflammatory response facilitates growth processes in skeletal muscle. - Highlights: • We examined mechanisms through which skeletal muscle cell expression of ICAM-1 facilitates events of in vitro myogenesis. • Expression of ICAM-1 by cultured myoblasts did not influence their ability to proliferate or differentiate. • Skeletal muscle cell expression of ICAM-1 augmented myoblast fusion, myotube alignment, myotube–myotube fusion, and myotube size. • ICAM-1 augmented myogenic processes through

  7. Signaling mechanisms of neurite outgrowth induced by the cell adhesion molecules NCAM and N-cadherin

    DEFF Research Database (Denmark)

    Hansen, S M; Berezin, V; Bock, E

    2008-01-01

    Formation of appropriate neural circuits depends on a complex interplay between extracellular guiding cues and intracellular signaling events that result in alterations of cytoskeletal dynamics and a neurite growth response. Surface-expressed cell adhesion molecules (CAMs) interact with the surro......Formation of appropriate neural circuits depends on a complex interplay between extracellular guiding cues and intracellular signaling events that result in alterations of cytoskeletal dynamics and a neurite growth response. Surface-expressed cell adhesion molecules (CAMs) interact...... extracellular guidance cues to intracellular events and thereby regulating neurite outgrowth. In this review, we focus on two CAMs, the neural cell adhesion molecule (NCAM) and N-cadherin, and their ability to mediate signaling associated with a neurite outgrowth response. In particular, we will focus on direct...

  8. Structural and cell adhesion properties of zebrafish syndecan-4 are shared with higher vertebrates

    DEFF Research Database (Denmark)

    Whiteford, James; Ko, Sunggeon; Lee, Weontae

    2008-01-01

    , but no molecular and cellular studies have been reported. Here it is demonstrated that key functional attributes of syndecan-4 are common to both zebrafish and mammalian homologues. These include glycosaminoglycan substitution, a NXIP motif in the extracellular domain that promotes integrin-mediated cell adhesion......The syndecan proteoglycans are an ancient class of receptor, bearing heparan sulfate chains that interact with numerous potential ligands including growth factors, morphogens, and extracellular matrix molecules. The single syndecan of invertebrates appears not to have cell adhesion roles......, but these have been described for mammalian paralogues, especially syndecan-4. This member is best understood in terms of interactions, signaling, and structure of its cytoplasmic domain. The zebrafish homologue of syndecan-4 has been genetically linked to cell adhesion and migration in zebrafish embryos...

  9. HOS cell adhesion on Ti6Al4V ELI texturized by CO2 laser

    Science.gov (United States)

    Sandoval-Amador, A.; Bayona–Alvarez, Y. M.; Carreño Garcia, H.; Escobar-Rivero, P.; Y Peña-Ballesteros, D.

    2017-12-01

    In this work, the response of HOS cells on Ti6Al4V ELI textured surfaces by a CO2 laser was evaluated. The test surfaces were; smooth Ti6Al4V, used as the control, and four textured surfaces with linear geometry. These four surfaces had different separation distances between textured lines, D1 (1000 microns), D2 (750 microns), D3 (500 microns) and D4 (250 microns). Toxicity of textured surfaces was assessed by MTT and the cellular adhesion test was performed using HOS ATCC CRL 1543 line cells. This test was done after 5 days of culture in a RPMI 1640 medium supplemented with 10% fetal bovine serum and 1% antibiotics. The results showed that the linear textures present 23% toxicity after 30 days of incubation, nevertheless, the adhesion tests results are inconclusive in such conditions and therefore the effect of the line separation on the cell adhesion cannot be determined.

  10. Co-immobilization of active antibiotics and cell adhesion peptides on calcium based biomaterials.

    Science.gov (United States)

    Palchesko, Rachelle N; Buckholtz, Gavin A; Romeo, Jared D; Gawalt, Ellen S

    2014-07-01

    Two bioactive molecules with unrelated functions, vancomycin and a cell adhesion peptide, were immobilized on the surface of a potential bone scaffold material, calcium aluminum oxide. In order to accomplish immobilization and retain bioactivity three sequential surface functionalization strategies were compared: 1.) vancomycin was chemically immobilized before a cell adhesion peptide (KRSR), 2.) vancomycin was chemically immobilized after KRSR and 3.) vancomycin was adsorbed after binding the cell adhesion peptide. Both molecules remained on the surface and active using all three reaction sequences and after autoclave sterilization based on osteoblast attachment, bacterial turbidity and bacterial zone inhibition test results. However, the second strategy was superior at enhancing osteoblast attachment and significantly decreasing bacterial growth when compared to the other sequences. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Actin filaments regulate the adhesion between the plasma membrane and the cell wall of tobacco guard cells.

    Science.gov (United States)

    Yu, Qin; Ren, Jing-Jing; Kong, Lan-Jing; Wang, Xiu-Ling

    2018-01-01

    During the opening and closing of stomata, guard cells undergo rapid and reversible changes in their volume and shape, which affects the adhesion of the plasma membrane (PM) to the cell wall (CW). The dynamics of actin filaments in guard cells are involved in stomatal movement by regulating structural changes and intracellular signaling. However, it is unclear whether actin dynamics regulate the adhesion of the PM to the CW. In this study, we investigated the relationship between actin dynamics and PM-CW adhesion by the hyperosmotic-induced plasmolysis of tobacco guard cells. We found that actin filaments in guard cells were depolymerized during mannitol-induced plasmolysis. The inhibition of actin dynamics by treatment with latrunculin B or jasplakinolide and the disruption of the adhesion between the PM and the CW by treatment with RGDS peptide (Arg-Gly-Asp-Ser) enhanced guard cell plasmolysis. However, treatment with latrunculin B alleviated the RGDS peptide-induced plasmolysis and endocytosis. Our results reveal that the actin depolymerization is involved in the regulation of the PW-CW adhesion during hyperosmotic-induced plasmolysis in tobacco guard cells.

  12. Tenascin-C enhances pancreatic cancer cell growth and motility and affects cell adhesion through activation of the integrin pathway.

    Directory of Open Access Journals (Sweden)

    Igor Paron

    Full Text Available BACKGROUND: Pancreatic cancer (PDAC is characterized by an abundant fibrous tissue rich in Tenascin-C (TNC, a large ECM glycoprotein mainly synthesized by pancreatic stellate cells (PSCs. In human pancreatic tissues, TNC expression increases in the progression from low-grade precursor lesions to invasive cancer. Aim of this study was the functional characterization of the effects of TNC on biologic relevant properties of pancreatic cancer cells. METHODS: Proliferation, migration and adhesion assays were performed on pancreatic cancer cell lines treated with TNC or grown on a TNC-rich matrix. Stable transfectants expressing the large TNC splice variant were generated to test the effects of endogenous TNC. TNC-dependent integrin signaling was investigated by immunoblotting, immunofluorescence and pharmacological inhibition. RESULTS: Endogenous TNC promoted pancreatic cancer cell growth and migration. A TNC-rich matrix also enhanced migration as well as the adhesion to the uncoated growth surface of poorly differentiated cell lines. In contrast, adhesion to fibronectin was significantly decreased in the presence of TNC. The effects of TNC on cell adhesion were paralleled by changes in the activation state of paxillin and Akt. CONCLUSION: TNC affects proliferation, migration and adhesion of poorly differentiated pancreatic cancer cell lines and might therefore play a role in PDAC spreading and metastasis in vivo.

  13. Controlling Interdiffusion, Interfacial Composition, and Adhesion in Polymer Solar Cells

    KAUST Repository

    Dupont, Stephanie R.; Voroshazi, Eszter; Nordlund, Dennis; Vandewal, Koen; Dauskardt, Reinhold H.

    2014-01-01

    © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. NEXAFS spectroscopy is used to precisely quantify the interfacial composition and P3HT chain orientation at the weak P3HT:PCBM/PEDOT:PSS interface. An increase of P3HT:PCBM and PEDOT:PSS interdiffusion with post electrode deposition annealing time and temperature is found to be the underlying mechanism for effectively improving the interlayer adhesion, which is essential for the commercial realization of organic photovoltaic devices.

  14. Controlling Interdiffusion, Interfacial Composition, and Adhesion in Polymer Solar Cells

    KAUST Repository

    Dupont, Stephanie R.

    2014-07-10

    © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. NEXAFS spectroscopy is used to precisely quantify the interfacial composition and P3HT chain orientation at the weak P3HT:PCBM/PEDOT:PSS interface. An increase of P3HT:PCBM and PEDOT:PSS interdiffusion with post electrode deposition annealing time and temperature is found to be the underlying mechanism for effectively improving the interlayer adhesion, which is essential for the commercial realization of organic photovoltaic devices.

  15. KHYG-1 and NK-92 represent different subtypes of LFA-1-mediated NK cell adhesiveness.

    Science.gov (United States)

    Suck, Garnet; Tan, Suet-Mien; Chu, Sixian; Niam, Madelaine; Vararattanavech, Ardcharaporn; Lim, Tsyr Jong; Koh, Mickey B C

    2011-01-01

    Novel cancer cellular therapy approaches involving long-term ex vivo IL-2 stimulated highly cytotoxic natural killer (NK) cells are emerging. However, adhesion properties of such NK cells are not very well understood. Herein, we describe the novel observation of permanently activated alphaLbeta2 integrin leukocyte function-associated antigen (LFA)-1 adhesion receptor in long-term IL-2 activated NK cells and the permanent NK cell lines KHYG-1 and NK-92. We show that such cytokine activated NK effectors constitutively adhered to the LFA-1-ligand ICAM-1, whereas binding to the lower affinity ligand ICAM-3 required additional exogenous activating conditions. The results demonstrate an extended conformation and an intermediate affinity state for the LFA-1 population expressed by the NK cells. Interestingly, adhesion to ICAM-1 or K562 induced pronounced cell spreading in KHYG-1, but not in NK-92, and partially in long-term IL-2 stimulated primary NK cells. It is conceivable that such differential adhesion characteristics may impact motility potential of such NK effectors with relevance to clinical tumor targeting. KHYG-1 could be a useful model in planning future targeted therapeutic approaches involving NK effectors with augmented functions.

  16. Adhesive interaction measured between AFM probe and lung epithelial type II cells

    International Nuclear Information System (INIS)

    Leonenko, Zoya; Finot, Eric; Amrein, Matthias

    2007-01-01

    The toxicity of inhaled nanoparticles entering the body through the lung is thought to be initially defined by the electrostatic and adhesive interaction of the particles with lung's wall. Here, we investigated the first step of the interaction of nanoparticles with lung epithelial cells using atomic force microscope (AFM) as a force apparatus. Nanoparticles were modeled by the apex of the AFM tip and the forces of interaction between the tip and the cell analyzed over time. The adhesive force and work of adhesion strongly increased for the first 100 s of contact and then leveled out. During this time, the tip was penetrating deeply into the cell. It first crossed a stiff region of the cell and then entered a much more compliant cell region. The work of adhesion and its progression over time were not dependent on the load with which the tip was brought into contact with the cell. We conclude that the initial thermodynamic aspects and the time course of the uptake of nanoparticles by lung epithelial cells can be studied using our experimental approach. It is discussed how the potential health threat posed by nanoparticles of different size and surface characteristics can be evaluated using the method presented

  17. [The effect of Angelica sinensis on adhesion, invasion, migration and metastasis of melanoma cells].

    Science.gov (United States)

    Gu, Qin; Xu, Jian-ya; Cheng, Luo-gen; Xia, Wei-jun

    2007-03-01

    To study the effect of Angelica sinensis on invasion, adhesion, migration and metastasis of B16-BL6 metastatic mouse melanoma cells and discuss its functional mechanism. The proliferation, adhesion, invasion and migration capacity of B16-BL6 metastatic cells was evaluated by MTT assay, adhesion assay and reconstituted basement membrane invasion and migration assay in vitro respectively. Mouse spontaneous melanoma model was used to study the effect of Angelica sinensis on metastasis in vivo. The extract of Angelica sinensis inhibited the proliferation of B16-BL6 metastatic cells and its migration capacity significantly. It regulated bidirectionally the adhesion of B16-BL6 metastatic cells to the basement component laminin while it had no effect on the invasion capacity. In the mouse spotaneous melanoma model, the lung metastatic nodes number and its volume were significantly decreased after continuously treated with the extract of Angelica sinensis at the concentration of 3.67 mg/kg. The extract of Angelica sinensis can inhibit the metastasis of of B16-BL6 metastatic mouse melanoma cells and its mechanism is maybe that Angelica sinensis can inhibit the B16-BL6 cells adhering to the ECM and reduce the migration of B16-BL6 cells.

  18. Cell Adhesion and Proliferation on Sulfonated and Non-Modified Chitosan Films.

    Science.gov (United States)

    Martínez-Campos, Enrique; Civantos, Ana; Redondo, Juan Alfonso; Guzmán, Rodrigo; Pérez-Perrino, Mónica; Gallardo, Alberto; Ramos, Viviana; Aranaz, Inmaculada

    2017-05-01

    Three types of chitosan-based films have been prepared and evaluated: a non-modified chitosan film bearing cationizable aliphatic amines and two films made of N-sulfopropyl chitosan derivatives bearing both aliphatic amines and negative sulfonate groups at different ratios. Cell adhesion and proliferation on chitosan films of C2C12 pre-myoblastic cells and B16 cells as tumoral model have been tested. A differential cell behavior has been observed on chitosan films due to their different surface modification. B16 cells have shown lower vinculin expression when cultured on sulfonated chitosan films. This study shows how the interaction among cells and material surface can be modulated by physicochemical characteristics of the biomaterial surface, altering tumoral cell adhesion and proliferation processes.

  19. Conformational Dynamics of the Focal Adhesion Targeting Domain Control Specific Functions of Focal Adhesion Kinase in Cells

    KAUST Repository

    Kadaré, Gress

    2015-01-02

    Focal adhesion (FA) kinase (FAK) regulates cell survival and motility by transducing signals from membrane receptors. The C-terminal FA targeting (FAT) domain of FAK fulfils multiple functions, including recruitment to FAs through paxillin binding. Phosphorylation of FAT on Tyr925 facilitates FA disassembly and connects to the MAPK pathway through Grb2 association, but requires dissociation of the first helix (H1) of the four-helix bundle of FAT. We investigated the importance of H1 opening in cells by comparing the properties of FAK molecules containing wild-type or mutated FAT with impaired or facilitated H1 openings. These mutations did not alter the activation of FAK, but selectively affected its cellular functions, including self-association, Tyr925 phosphorylation, paxillin binding, and FA targeting and turnover. Phosphorylation of Tyr861, located between the kinase and FAT domains, was also enhanced by the mutation that opened the FAT bundle. Similarly phosphorylation of Ser910 by ERK in response to bombesin was increased by FAT opening. Although FAK molecules with the mutation favoring FAT opening were poorly recruited at FAs, they efficiently restored FA turnover and cell shape in FAK-deficient cells. In contrast, the mutation preventing H1 opening markedly impaired FAK function. Our data support the biological importance of conformational dynamics of the FAT domain and its functional interactions with other parts of the molecule.

  20. Chemical functionalization of bioceramics to enhance endothelial cells adhesion for tissue engineering.

    Science.gov (United States)

    Borcard, Françoise; Staedler, Davide; Comas, Horacio; Juillerat, Franziska Krauss; Sturzenegger, Philip N; Heuberger, Roman; Gonzenbach, Urs T; Juillerat-Jeanneret, Lucienne; Gerber-Lemaire, Sandrine

    2012-09-27

    To control the selective adhesion of human endothelial cells and human serum proteins to bioceramics of different compositions, a multifunctional ligand containing a cyclic arginine-glycine-aspartate (RGD) peptide, a tetraethylene glycol spacer, and a gallate moiety was designed, synthesized, and characterized. The binding of this ligand to alumina-based, hydroxyapatite-based, and calcium phosphate-based bioceramics was demonstrated. The conjugation of this ligand to the bioceramics induced a decrease in the nonselective and integrin-selective binding of human serum proteins, whereas the binding and adhesion of human endothelial cells was enhanced, dependent on the particular bioceramics.

  1. Biomechanics of P-selectin PSGL-1 bonds: Shear threshold and integrin-independent cell adhesion

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Zhihua; Goldsmith, Harry L.; MacIntosh, Fiona A.; Shankaran, Harish; Neelamegham, Sriram

    2006-03-01

    Platelet-leukocyte adhesion may contribute to thrombosis and inflammation. We examined the heterotypic interaction between unactivated neutrophils and either thrombin receptor activating peptide (TRAP) stimulated platelets or P-selectin bearing beads (Ps-beads) in suspension. Cone-plate viscometers were used to apply controlled shear rates from 14-3000/s. Platelet-neutrophil and bead-neutrophil adhesion analysis was performed using both flow cytometry and high-speed videomicroscopy. We observed that while blocking antibodies against either P-selectin or P-selectin glycoprotein ligand-1 (PSGL-1) alone inhibited platelet-neutrophil adhesion by ~60% at 140/s, these reagents completely blocked adhesion at 3000/s. Anti-Mac-1 alone did not alter platelet-neutrophil adhesion rates at any shear rate, though in synergy with selectin antagonists it abrogated cell binding. Unstimulated neutrophils avidly bound Ps-beads and activated platelets in an integrin-independent manner, suggesting that purely selectin-dependent cell adhesion is possible. In support of this, antagonists against P-selectin or PSGL-1 dissociated previously formed platelet-neutrophil and Ps-bead neutrophil aggregates under shear in a variety of experimental systems, including in assays performed with whole blood. In studies where medium viscosity and shear rate were varied, a subtle shear threshold for P-selectin PSGL-1 binding was also noted at shear rates<100/s and at force loading rates of ~300pN/sec. Results are discussed in light of biophysical computations that characterize the collision between unequal size particles in linear shear flow. Overall, our studies reveal an integrin-independent regime for cell adhesion that may be physiologically relevant.

  2. Ethanol exposure disrupts extraembryonic microtubule cytoskeleton and embryonic blastomere cell adhesion, producing epiboly and gastrulation defects

    Directory of Open Access Journals (Sweden)

    Swapnalee Sarmah

    2013-08-01

    Fetal alcohol spectrum disorder (FASD occurs when pregnant mothers consume alcohol, causing embryonic ethanol exposure and characteristic birth defects that include craniofacial, neural and cardiac defects. Gastrulation is a particularly sensitive developmental stage for teratogen exposure, and zebrafish is an outstanding model to study gastrulation and FASD. Epiboly (spreading blastomere cells over the yolk cell, prechordal plate migration and convergence/extension cell movements are sensitive to early ethanol exposure. Here, experiments are presented that characterize mechanisms of ethanol toxicity on epiboly and gastrulation. Epiboly mechanisms include blastomere radial intercalation cell movements and yolk cell microtubule cytoskeleton pulling the embryo to the vegetal pole. Both of these processes were disrupted by ethanol exposure. Ethanol effects on cell migration also indicated that cell adhesion was affected, which was confirmed by cell aggregation assays. E-cadherin cell adhesion molecule expression was not affected by ethanol exposure, but E-cadherin distribution, which controls epiboly and gastrulation, was changed. E-cadherin was redistributed into cytoplasmic aggregates in blastomeres and dramatically redistributed in the extraembryonic yolk cell. Gene expression microarray analysis was used to identify potential causative factors for early development defects, and expression of the cell adhesion molecule protocadherin-18a (pcdh18a, which controls epiboly, was significantly reduced in ethanol exposed embryos. Injecting pcdh18a synthetic mRNA in ethanol treated embryos partially rescued epiboly cell movements, including enveloping layer cell shape changes. Together, data show that epiboly and gastrulation defects induced by ethanol are multifactorial, and include yolk cell (extraembryonic tissue microtubule cytoskeleton disruption and blastomere adhesion defects, in part caused by reduced pcdh18a expression.

  3. Migratory and adhesive properties of Xenopus laevis primordial germ cells in vitro

    Directory of Open Access Journals (Sweden)

    Aliaksandr Dzementsei

    2013-11-01

    The directional migration of primordial germ cells (PGCs to the site of gonad formation is an advantageous model system to study cell motility. The embryonic development of PGCs has been investigated in different animal species, including mice, zebrafish, Xenopus and Drosophila. In this study we focus on the physical properties of Xenopus laevis PGCs during their transition from the passive to the active migratory state. Pre-migratory PGCs from Xenopus laevis embryos at developmental stages 17–19 to be compared with migratory PGCs from stages 28–30 were isolated and characterized in respect to motility and adhesive properties. Using single-cell force spectroscopy, we observed a decline in adhesiveness of PGCs upon reaching the migratory state, as defined by decreased attachment to extracellular matrix components like fibronectin, and a reduced adhesion to somatic endodermal cells. Data obtained from qPCR analysis with isolated PGCs reveal that down-regulation of E-cadherin might contribute to this weakening of cell-cell adhesion. Interestingly, however, using an in vitro migration assay, we found that movement of X. laevis PGCs can also occur independently of specific interactions with their neighboring cells. The reduction of cellular adhesion during PGC development is accompanied by enhanced cellular motility, as reflected in increased formation of bleb-like protrusions and inferred from electric cell-substrate impedance sensing (ECIS as well as time-lapse image analysis. Temporal alterations in cell shape, including contraction and expansion of the cellular body, reveal a higher degree of cellular dynamics for the migratory PGCs in vitro.

  4. Competition of Lactobacillus paracasei with Salmonella enterica for Adhesion to Caco-2 Cells

    Directory of Open Access Journals (Sweden)

    Alicja Jankowska

    2008-01-01

    Full Text Available Competition of commensal and probiotic bacteria with pathogens for adhesion and colonization is one of the important protective mechanisms of gastrointestinal tract. In this study, we examined the ability of Lactobacillus paracasei to inhibit the adhesion of pathogenic Salmonella enterica to human colon adenocarcinoma Caco-2 cells. Caco-2 cells were grown for 6 or 21 days to obtain nondifferentiated or well-differentiated cells, respectively. In adhesion experiments, bacteria were added to the cells for 2 or 4 hours. The number of attached bacteria was expressed as colony-forming units (CFUs, Caco-2 cells were counted in hematocytometer. Both bacterial strains used adhered better to well-differentiated than to nondifferentiated Caco-2 cells, however, the amount of Salmonella adhered to Caco-2 after 2 hours of contact was 12-fold higher in comparison to . paracasei and almost 27-fold higher after 4 hours of contact. Two types of experiments were done: coincubation (both bacteria were added to Caco-2 cells simultaneously, and preincubation (. paracasei was incubated with Caco-2 cells first, and then . enterica was added. In coincubation experiment, the presence of . paracasei decreased . enterica adhesion by 4-fold and in preincubation experiment even 7-fold. Generally, Lactobacillus spent culture supernatants (SCSs acted weaker as inhibitors of Salmonella adhesion in comparison to the whole . paracasei culture in coincubation experiment. In conclusion, the displacement of pathogens by lactic acid bacteria and its secretions showed here depends on the time of bacteria-epithelial cell contact, and also on the stage of Caco-2 differentiation.

  5. E. coli Nissle 1917 Affects Salmonella adhesion to porcine intestinal epithelial cells.

    Directory of Open Access Journals (Sweden)

    Peter Schierack

    Full Text Available BACKGROUND: The probiotic Escherichia coli strain Nissle 1917 (EcN has been shown to interfere in a human in vitro model with the invasion of several bacterial pathogens into epithelial cells, but the underlying molecular mechanisms are not known. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we investigated the inhibitory effects of EcN on Salmonella Typhimurium invasion of porcine intestinal epithelial cells, focusing on EcN effects on the various stages of Salmonella infection including intracellular and extracellular Salmonella growth rates, virulence gene regulation, and adhesion. We show that EcN affects the initial Salmonella invasion steps by modulating Salmonella virulence gene regulation and Salmonella SiiE-mediated adhesion, but not extra- and intracellular Salmonella growth. However, the inhibitory activity of EcN against Salmonella invasion always correlated with EcN adhesion capacities. EcN mutants defective in the expression of F1C fimbriae and flagellae were less adherent and less inhibitory toward Salmonella invasion. Another E. coli strain expressing F1C fimbriae was also adherent to IPEC-J2 cells, and was similarly inhibitory against Salmonella invasion like EcN. CONCLUSIONS: We propose that EcN affects Salmonella adhesion through secretory components. This mechanism appears to be common to many E. coli strains, with strong adherence being a prerequisite for an effective reduction of SiiE-mediated Salmonella adhesion.

  6. Green tea polyphenol tailors cell adhesivity of RGD displaying surfaces: multicomponent models monitored optically.

    Science.gov (United States)

    Peter, Beatrix; Farkas, Eniko; Forgacs, Eniko; Saftics, Andras; Kovacs, Boglarka; Kurunczi, Sandor; Szekacs, Inna; Csampai, Antal; Bosze, Szilvia; Horvath, Robert

    2017-02-10

    The interaction of the anti-adhesive coating, poly(L-lysine)-graft-poly(ethylene glycol) (PLL-g-PEG) and its Arg-Gly-Asp (RGD) functionalized form, PLL-g-PEG-RGD, with the green tea polyphenol, epigallocatechin-gallate (EGCg) was in situ monitored. After, the kinetics of cellular adhesion on the EGCg exposed coatings were recorded in real-time. The employed plate-based waveguide biosensor is applicable to monitor small molecule binding and sensitive to sub-nanometer scale changes in cell membrane position and cell mass distribution; while detecting the signals of thousands of adhering cells. The combination of this remarkable sensitivity and throughput opens up new avenues in testing complicated models of cell-surface interactions. The systematic studies revealed that, despite the reported excellent antifouling properties of the coatings, EGCg strongly interacted with them, and affected their cell adhesivity in a concentration dependent manner. Moreover, the differences between the effects of the fresh and oxidized EGCg solutions were first demonstrated. Using a semiempirical quantumchemical method we showed that EGCg binds to the PEG chains of PLL-g-PEG-RGD and effectively blocks the RGD sites by hydrogen bonds. The calculations supported the experimental finding that the binding is stronger for the oxidative products. Our work lead to a new model of polyphenol action on cell adhesion ligand accessibility and matrix rigidity.

  7. Urokinase links plasminogen activation and cell adhesion by cleavage of the RGD motif in vitronectin.

    Science.gov (United States)

    De Lorenzi, Valentina; Sarra Ferraris, Gian Maria; Madsen, Jeppe B; Lupia, Michela; Andreasen, Peter A; Sidenius, Nicolai

    2016-07-01

    Components of the plasminogen activation system including urokinase (uPA), its inhibitor (PAI-1) and its cell surface receptor (uPAR) have been implicated in a wide variety of biological processes related to tissue homoeostasis. Firstly, the binding of uPA to uPAR favours extracellular proteolysis by enhancing cell surface plasminogen activation. Secondly, it promotes cell adhesion and signalling through binding of the provisional matrix protein vitronectin. We now report that uPA and plasmin induces a potent negative feedback on cell adhesion through specific cleavage of the RGD motif in vitronectin. Cleavage of vitronectin by uPA displays a remarkable receptor dependence and requires concomitant binding of both uPA and vitronectin to uPAR Moreover, we show that PAI-1 counteracts the negative feedback and behaves as a proteolysis-triggered stabilizer of uPAR-mediated cell adhesion to vitronectin. These findings identify a novel and highly specific function for the plasminogen activation system in the regulation of cell adhesion to vitronectin. The cleavage of vitronectin by uPA and plasmin results in the release of N-terminal vitronectin fragments that can be detected in vivo, underscoring the potential physiological relevance of the process. © 2016 The Authors.

  8. The effect of cell surface components on adhesion ability of Lactobacillus rhamnosus.

    Science.gov (United States)

    Polak-Berecka, Magdalena; Waśko, Adam; Paduch, Roman; Skrzypek, Tomasz; Sroka-Bartnicka, Anna

    2014-10-01

    The aim of this study was to analyze the cell envelope components and surface properties of two phenotypes of Lactobacillus rhamnosus isolated from the human gastrointestinal tract. The ability of the bacteria to adhere to human intestinal cells and to aggregate with other bacteria was determined. L. rhamnosus strains E/N and PEN differed with regard to the presence of exopolysaccharides (EPS) and specific surface proteins. Transmission electron microscopy showed differences in the structure of the outer cell surface of the strains tested. Bacterial surface properties were analyzed by Fourier transform infrared spectroscopy, fatty acid methyl esters and hydrophobicity assays. Aggregation capacity and adhesion of the tested strains to the human colon adenocarcinoma cell line HT29 was determined. The results indicated a high adhesion and aggregation ability of L. rhamnosus PEN, which possessed specific surface proteins, had a unique fatty acid content, and did not synthesize EPS. Adherence of L. rhamnosus was dependent on specific interactions and was promoted by surface proteins (42-114 kDa) and specific fatty acids. Polysaccharides likely hindered bacterial adhesion and aggregation by masking protein receptors. This study provides information on the cell envelope constituents of lactobacilli that influence bacterial aggregation and adhesion to intestinal cells. This knowledge will help to understand better their specific contribution in commensal-host interactions and adaptation to this ecological niche.

  9. Effect of Hydrofluoric Acid Etching Time on Titanium Topography, Chemistry, Wettability, and Cell Adhesion.

    Directory of Open Access Journals (Sweden)

    R Zahran

    Full Text Available Titanium implant surface etching has proven an effective method to enhance cell attachment. Despite the frequent use of hydrofluoric (HF acid, many questions remain unresolved, including the optimal etching time and its effect on surface and biological properties. The objective of this study was to investigate the effect of HF acid etching time on Ti topography, surface chemistry, wettability, and cell adhesion. These data are useful to design improved acid treatment and obtain an improved cell response. The surface topography, chemistry, dynamic wetting, and cell adhesiveness of polished Ti surfaces were evaluated after treatment with HF acid solution for 0, 2; 3, 5, 7, or 10 min, revealing a time-dependent effect of HF acid on their topography, chemistry, and wetting. Roughness and wetting increased with longer etching time except at 10 min, when roughness increased but wetness decreased. Skewness became negative after etching and kurtosis tended to 3 with longer etching time. Highest cell adhesion was achieved after 5-7 min of etching time. Wetting and cell adhesion were reduced on the highly rough surfaces obtained after 10-min etching time.

  10. Tumor cell adhesion to endothelial cells is increased by endotoxin via an upregulation of beta-1 integrin expression.

    LENUS (Irish Health Repository)

    Andrews, E J

    2012-02-03

    BACKGROUND: Recent studies have demonstrated that metastatic disease develops from tumor cells that adhere to endothelial cells and proliferate intravascularly. The beta-1 integrin family and its ligand laminin have been shown to be important in tumor-to-endothelial cell adhesion. Lipopolysaccharide (LPS) has been implicated in the increased metastatic tumor growth that is seen postoperatively. We postulated that LPS increases tumor cell expression of beta-1 integrins and that this leads to increased adhesion. METHODS: The human metastatic colon cancer cell line LS174T was labeled with an enhanced green fluorescent protein (eGFP) using retroviral transfection. Cell cultures were treated with LPS for 1, 2, and 4 h (n = 6 each) and were subsequently cocultured for 30 or 120 min with confluent human umbilical vein endothelial cells (HUVECs), to allow adherence. Adherent tumor cells were counted using fluorescence microscopy. These experiments were carried out in the presence or absence of a functional blocking beta-1 integrin monoclonal antibody (4B4). Expression of beta-1 integrin and laminin on tumor and HUVECs was assessed using flow cytometric analysis. Tumor cell NF-kappaB activation after incubation with LPS was measured. RESULTS: Tumor cell and HUVEC beta-1 integrin expression and HUVEC expression of laminin were significantly (P < 0.05) enhanced after incubation with LPS. Tumor cell adhesion to HUVECs was significantly increased. Addition of the beta-1 integrin blocking antibody reduced tumor cell adhesion to control levels. LPS increased tumor cell NF-kappaB activation. CONCLUSIONS: Exposure to LPS increases tumor cell adhesion to the endothelium through a beta-1 integrin-mediated pathway that is NF-kappaB dependent. This may provide a target for immunotherapy directed at reducing postoperative metastatic tumor growth.

  11. Intercellular Adhesion Molecule-1 and Vascular Cell Adhesion Molecule Are Induced by Ionizing Radiation on Lymphatic Endothelium

    International Nuclear Information System (INIS)

    Rodriguez-Ruiz, María E.; Garasa, Saray; Rodriguez, Inmaculada; Solorzano, Jose Luis; Barbes, Benigno; Yanguas, Alba; Teijeira, Alvaro; Etxeberria, Iñaki; Aristu, José Javier; Halin, Cornelia; Melero, Ignacio; Rouzaut, Ana

    2017-01-01

    Purpose/Objectives: The goal of this study was to assess the effects of ionizing radiation on the expression of the integrin ligands ICAM-1 and VCAM that control leucocyte transit by lymphatic endothelial cells. Materials/Methods: Confluent monolayers of primary human lymphatic endothelial cells (LEC) were irradiated with single dose of 2, 5, 10 or 20 Gy, with 6 MeV-x-rays using a Linear-Accelerator. ICAM-1 and VCAM expression was determined by flow cytometry. Human tissue specimens received a single dose of 20 Gy with 15 MeV-x-rays. MC38, B16-OVA or B16-VEGF-C tumors grown in C57BL/6 mice were irradiated with single dose of 20Gy using a Linear-Accelerator fitted with a 10mm Radiosurgery collimator. Clinical samples were obtained from patients previous and 4 weeks after complete standard radiotherapy. ICAM-1 and VCAM expression was detected in all tissue specimens by confocal microscopy. To understand the role of TGFβ in this process anti-TGFβ blocking mAb were injected i.p. 30min before radiotherapy. Cell adhesion to irradiated LEC was analyzed in adhesion experiments performed in the presence or in the absence of anti- TGFβ and /or anti-ICAM1 blocking mAb. Results: We demonstrate that lymphatic endothelial cells in tumor samples experience induction of surface ICAM-1 and VCAM when exposed to ionizing radiation in a dose- and time-dependent manner. These effects can be recapitulated in cultured LEC, and are in part mediated by TGFβ. These data are consistent with increases in ICAM-1 and VCAM expression on LYVE-1+ endothelial cells in freshly explanted human tumor tissue and in mouse transplanted tumors after radiotherapy. Finally, ICAM-1 and VCAM expression accounts for enhanced adherence of human T lymphocytes to irradiated LEC. Conclusion: Our results show induction of ICAM-1 and VCAM on LVs in irradiated lesions and offer a starting point for elucidating the biological and therapeutic implications of targeting leukocyte traffic in combination to

  12. Intercellular Adhesion Molecule-1 and Vascular Cell Adhesion Molecule Are Induced by Ionizing Radiation on Lymphatic Endothelium

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez-Ruiz, María E., E-mail: mrruiz@unav.es [Division of Immunology and Immunotherapy, Center for Applied Medical Research, University of Navarra, Pamplona (Spain); Radiation Oncology, University Clinic, University of Navarra, Pamplona (Spain); Garasa, Saray; Rodriguez, Inmaculada [Division of Immunology and Immunotherapy, Center for Applied Medical Research, University of Navarra, Pamplona (Spain); Solorzano, Jose Luis; Barbes, Benigno [Radiation Oncology, University Clinic, University of Navarra, Pamplona (Spain); Yanguas, Alba [Division of Immunology and Immunotherapy, Center for Applied Medical Research, University of Navarra, Pamplona (Spain); Department of Biochemistry and Genetics, University of Navarra, Pamplona (Spain); Teijeira, Alvaro; Etxeberria, Iñaki [Division of Immunology and Immunotherapy, Center for Applied Medical Research, University of Navarra, Pamplona (Spain); Aristu, José Javier [Radiation Oncology, University Clinic, University of Navarra, Pamplona (Spain); Halin, Cornelia [Pharmaceutical Immunology, Institute of Pharmaceutical Sciences, ETH Zurich, Zurich (Switzerland); Melero, Ignacio [Division of Immunology and Immunotherapy, Center for Applied Medical Research, University of Navarra, Pamplona (Spain); Radiation Oncology, University Clinic, University of Navarra, Pamplona (Spain); Rouzaut, Ana [Division of Immunology and Immunotherapy, Center for Applied Medical Research, University of Navarra, Pamplona (Spain); Department of Biochemistry and Genetics, University of Navarra, Pamplona (Spain)

    2017-02-01

    Purpose/Objectives: The goal of this study was to assess the effects of ionizing radiation on the expression of the integrin ligands ICAM-1 and VCAM that control leucocyte transit by lymphatic endothelial cells. Materials/Methods: Confluent monolayers of primary human lymphatic endothelial cells (LEC) were irradiated with single dose of 2, 5, 10 or 20 Gy, with 6 MeV-x-rays using a Linear-Accelerator. ICAM-1 and VCAM expression was determined by flow cytometry. Human tissue specimens received a single dose of 20 Gy with 15 MeV-x-rays. MC38, B16-OVA or B16-VEGF-C tumors grown in C57BL/6 mice were irradiated with single dose of 20Gy using a Linear-Accelerator fitted with a 10mm Radiosurgery collimator. Clinical samples were obtained from patients previous and 4 weeks after complete standard radiotherapy. ICAM-1 and VCAM expression was detected in all tissue specimens by confocal microscopy. To understand the role of TGFβ in this process anti-TGFβ blocking mAb were injected i.p. 30min before radiotherapy. Cell adhesion to irradiated LEC was analyzed in adhesion experiments performed in the presence or in the absence of anti- TGFβ and /or anti-ICAM1 blocking mAb. Results: We demonstrate that lymphatic endothelial cells in tumor samples experience induction of surface ICAM-1 and VCAM when exposed to ionizing radiation in a dose- and time-dependent manner. These effects can be recapitulated in cultured LEC, and are in part mediated by TGFβ. These data are consistent with increases in ICAM-1 and VCAM expression on LYVE-1+ endothelial cells in freshly explanted human tumor tissue and in mouse transplanted tumors after radiotherapy. Finally, ICAM-1 and VCAM expression accounts for enhanced adherence of human T lymphocytes to irradiated LEC. Conclusion: Our results show induction of ICAM-1 and VCAM on LVs in irradiated lesions and offer a starting point for elucidating the biological and therapeutic implications of targeting leukocyte traffic in combination to

  13. Focal adhesion interactions with topographical structures: a novel method for immuno-SEM labelling of focal adhesions in S-phase cells.

    Science.gov (United States)

    Biggs, M J P; Richards, R G; Wilkinson, C D W; Dalby, M J

    2008-07-01

    Current understanding of the mechanisms involved in osseointegration following implantation of a biomaterial has led to adhesion quantification being implemented as an assay of cytocompatibility. Such measurement can be hindered by intra-sample variation owing to morphological changes associated with the cell cycle. Here we report on a new scanning electron microscopical method for the simultaneous immunogold labelling of cellular focal adhesions and S-phase nuclei identified by BrdU incorporation. Prior to labelling, cellular membranes are removed by tritonization and antigens of non-interest blocked by serum incubation. Adhesion plaque-associated vinculin and S-phase nuclei were both separately labelled with a 1.4 nm gold colloid and visualized by subsequent colloid enhancement via silver deposition. This study is specifically concerned with the effects microgroove topographies have on adhesion formation in S-phase osteoblasts. By combining backscattered electron (BSE) imaging with secondary electron (SE) imaging it was possible to visualize S-phase nuclei and the immunogold-labelled adhesion sites in one energy 'plane' and the underlying nanotopography in another. Osteoblast adhesion to these nanotopographies was ascertained by quantification of adhesion complex formation.

  14. Decreased soluble cell adhesion molecules after tirofiban infusion in patients with unstable angina pectoris

    Directory of Open Access Journals (Sweden)

    Aliyev Emil

    2004-04-01

    Full Text Available Abstract Aim The inflammatory response, initiated by neutrophil and monocyte adhesion to endothelial cells, is important in the pathogenesis of acute coronary syndromes. Platelets play an important role in inflammatory process by interacting with monocytes and neutrophils. In this study, we investigated the effect of tirofiban on the levels of cell adhesion molecules (soluble intercellular adhesion molecule-1, sICAM-1, and vascular cell adhesion molecule-1, sVCAM-1 in patients with unstable angina pectoris (AP. Methods Thirty-five patients with unstable AP (Group I, ten patients with stable AP (Group II and ten subjects who had angiographycally normal coronary arteries (Group III were included the study. Group I was divided into two subgroups for the specific treatment regimens: Group IA (n = 15 received tirofiban and Group IB (n = 20 did not. Blood samples for investigating the cell adhesion molecules were drawn at zero time (baseline; 0 h in all patients and at 72 h in Group I. Results The baseline levels of sICAM-1 and sVCAM-1 were higher in Group I than in Groups II and III. They were higher in Group IA than in Group IB. However, the sICAM-1 and sVCAM-1 levels decreased significantly in Group IA after tirofiban infusion. In contrast, these levels remained unchanged or were increased above the baseline value in Group IB at 72 h. Conclusion The levels of cell adhesion molecules in patients with unstable AP decreased significantly after tirofiban infusion. Inhibition of platelet function by specific glycoprotein IIb/IIIa antagonists may decrease platelet-mediated inflammation and the ischemic end-point.

  15. Effects of Flowing RBCs on Adhesion of a Circulating Tumor Cell in Microvessels

    Science.gov (United States)

    Xiao, L.L.; Liu, Y.; Chen, S.; Fu, B.M.

    2016-01-01

    Adhesion of circulating tumor cells (CTCs) to the microvessel wall largely depends on the blood hydrodynamic conditions, one of which is the blood viscosity. Since blood is a non-Newtonian fluid, whose viscosity increases with hematocrit, in the microvessels at low shear rate. In this study, the effects of hematocrit, vessel size, flow rate and red blood cells (RBCs) aggregation on adhesion of a CTC in the microvessels were numerically investigated using dissipative particle dynamics. The membrane of cells was represented by a spring-based network connected by elastic springs to characterize its deformation. RBCs aggregation was modelled by a Morse potential function based on depletion-mediated assumption and the adhesion of the CTC to the vessel wall was achieved by the interactions between receptors and ligands at the CTC and those at the endothelial cells forming the vessel wall. The results demonstrated that in the microvessel of 15μm diameter, the CTC has an increasing probability of adhesion with the hematocrit due to a growing wall-directed force, resulting in a larger number of receptor-ligand bonds formed on the cell surface. However, with the increase in microvessel size, an enhanced lift force at higher hematocrit detaches the initial adherent CTC quickly. If the microvessel is comparable to the CTC in diameter, CTC adhesion is independent of Hct. In addition, the velocity of CTC is larger than the average blood flow velocity in smaller microvessels and the relative velocity of CTC decreases with the increase in microvessel size. An increased blood flow resistance in the presence of CTC was also found. Moreover, it was found that the large deformation induced by high flow rate and the presence of aggregation promote the adhesion of CTC. PMID:27738841

  16. Adhesion molecule profiles of B-cell non-Hodgkin's lymphomas in the leukemic phase

    Directory of Open Access Journals (Sweden)

    D.M. Matos

    2006-10-01

    Full Text Available We evaluated the expression of 10 adhesion molecules on peripheral blood tumor cells of 17 patients with chronic lymphocytic leukemia, 17 with mantle-cell lymphoma, and 13 with nodal or splenic marginal B-cell lymphoma, all in the leukemic phase and before the beginning of any therapy. The diagnosis of B-cell non-Hodgkin's lymphomas was based on cytological, histological, immunophenotypic, and molecular biology methods. The mean fluorescence intensity of the adhesion molecules in tumor cells was measured by flow cytometry of CD19-positive cells and differed amongst the types of lymphomas. Comparison of chronic lymphocytic leukemia and mantle-cell lymphoma showed that the former presented a higher expression of CD11c and CD49c, and a lower expression of CD11b and CD49d adhesion molecules. Comparison of chronic lymphocytic leukemia and marginal B-cell lymphoma showed that the former presented a higher expression of CD49c and a lower expression of CD11a, CD11b, CD18, CD49d, CD29, and CD54. Finally, comparison of mantle-cell lymphoma and marginal B-cell lymphoma showed that marginal B-cell lymphoma had a higher expression of CD11a, CD11c, CD18, CD29, and CD54. Thus, the CD49c/CD49d pair consistently demonstrated a distinct pattern of expression in chronic lymphocytic leukemia compared with mantle-cell lymphoma and marginal B-cell lymphoma, which could be helpful for the differential diagnosis. Moreover, the distinct profiles of adhesion molecules in these diseases may be responsible for their different capacities to invade the blood stream.

  17. New Serum Markers for Small-Cell Lung Cancer. II. The Neural Cell Adhesion Molecule, NCAM

    DEFF Research Database (Denmark)

    Vangsted, A.; Drivsholm, L.; Andersen, E.

    1994-01-01

    The neural cell adhesion molecule (NCAM) was recently suggested as a marker for small-cell lung cancer (SCLC). Immunohistochemical analysis demonstrated the presence of the NCAM in 78% of SCLC patients and in 25% of patients with other cancer forms. NCAM was proposed to be the most sensitive marker...... for SCLC, and it may also be an important prognostic marker for SCLC. We used a competitive ELISA to analyze the concentrations of NCAM in sera from 96 SCLC patients, 16 patients with non-SCLC, 4 patients with other cancer forms, and 16 healthy controls. All sera were collected at the time of diagnosis......, before the patients received chemotherapy. The polyclonal antibody used in the assay recognized all three isoforms of NCAM. The concentration of NCAM was related to clinical parameters of the patients such as age, sex, blood group status, stage of disease, organ site involvement of metastases, survival...

  18. Regulated expression of the neural cell adhesion molecule L1 by specific patterns of neural impulses.

    Science.gov (United States)

    Itoh, K; Stevens, B; Schachner, M; Fields, R D

    1995-11-24

    Development of the mammalian nervous system is regulated by neural impulse activity, but the molecular mechanisms are not well understood. If cell recognition molecules [for example, L1 and the neural cell adhesion molecule (NCAM)] were influenced by specific patterns of impulse activity, cell-cell interactions controlling nervous system structure could be regulated by nervous system function at critical stages of development. Low-frequency electrical pulses delivered to mouse sensory neurons in culture (0.1 hertz for 5 days) down-regulated expression of L1 messenger RNA and protein (but not NCAM). Fasciculation of neurites, adhesion of neuroblastoma cells, and the number of Schwann cells on neurites was reduced after 0.1-hertz stimulation, but higher frequencies or stimulation after synaptogenesis were without effect.

  19. HOS cell adhesion on Ti6Al4V surfaces texturized by laser engraving

    Science.gov (United States)

    Sandoval Amador, A.; Carreño Garcia, H.; Escobar Rivero, P.; Peña Ballesteros, D. Y.; Estupiñán Duran, H. A.

    2016-02-01

    The cell adhesion of the implant is determinate by the chemical composition, topography, wettability, surface energy and biocompatibility of the biomaterial. In this work the interaction between human osteosarcoma HOS cells and textured Ti6Al4V surfaces were evaluated. Ti6Al4V surfaces were textured using a CO2 laser in order to obtain circular spots on the surfaces. Test surfaces were uncoated (C1) used as a control surface, and surfaces with points obtained by laser engraving, with 1mm spacing (C2) and 0.5mm (C3). The HOS cells were cultured in RPMI-1640 medium with 10% fetal bovine serum and 1% antibiotics. No cells toxicity after one month incubation time occurred. The increased cell adhesion and cell spreading was observed after 1, 3 and 5 days without significant differences between the sample surfaces (C2 and C3) and control (uncoated) at the end of the experiment.

  20. HOS cell adhesion on Ti6Al4V surfaces texturized by laser engraving

    International Nuclear Information System (INIS)

    Sandoval Amador, A; Carreño Garcia, H; Escobar Rivero, P; Peña Ballesteros, D Y; Estupiñán Duran, H A

    2016-01-01

    The cell adhesion of the implant is determinate by the chemical composition, topography, wettability, surface energy and biocompatibility of the biomaterial. In this work the interaction between human osteosarcoma HOS cells and textured Ti 6 Al 4 V surfaces were evaluated. Ti 6 Al 4 V surfaces were textured using a CO 2 laser in order to obtain circular spots on the surfaces. Test surfaces were uncoated (C1) used as a control surface, and surfaces with points obtained by laser engraving, with 1mm spacing (C2) and 0.5mm (C3). The HOS cells were cultured in RPMI-1640 medium with 10% fetal bovine serum and 1% antibiotics. No cells toxicity after one month incubation time occurred. The increased cell adhesion and cell spreading was observed after 1, 3 and 5 days without significant differences between the sample surfaces (C2 and C3) and control (uncoated) at the end of the experiment. (paper)

  1. Correlation of Cell Surface Biomarker Expression Levels with Adhesion Contact Angle Measured by Lateral Microscopy.

    Science.gov (United States)

    Walz, Jenna A; Mace, Charles R

    2018-06-05

    Immunophenotyping is typically achieved using flow cytometry, but any influence a biomarker may have on adhesion or surface recognition cannot be determined concurrently. In this manuscript, we demonstrate the utility of lateral microscopy for correlating cell surface biomarker expression levels with quantitative descriptions of cell morphology. With our imaging system, we observed single cells from two T cell lines and two B cell lines adhere to antibody-coated substrates and quantified this adhesion using contact angle measurements. We found that SUP-T1 and CEM CD4+ cells, both of which express similar levels of CD4, experienced average changes in contact angle that were not statistically different from one another on surfaces coated in anti-CD4. However, MAVER-1 and BJAB K20 cells, both of which express different levels of CD20, underwent average changes in contact angle that were significantly different from one another on surfaces coated in anti-CD20. Our results indicate that changes in cell contact angles on antibody-coated substrates reflect the expression levels of corresponding antigens on the surfaces of cells as determined by flow cytometry. Our lateral microscopy approach offers a more reproducible and quantitative alternative to evaluate adhesion compared to commonly used wash assays and can be extended to many additional immunophenotyping applications to identify cells of interest within heterogeneous populations.

  2. Inhibitory effects of OK-432 (Picibanil) on cellular proliferation and adhesive capacity of breast carcinoma cells.

    Science.gov (United States)

    Horii, Yoshio; Iino, Yuichi; Maemura, Michio; Horiguchi, Jun; Morishita, Yasuo

    2005-02-01

    We investigated the potent inhibitory effects of OK-432 (Picibanil) on both cellular adhesion and cell proliferation of estrogen-dependent (MCF-7) or estrogen-independent (MDA-MB-231) breast carcinoma cells. Cellular proliferation of both MCF-7 and MDA-MB-231 cells was markedly inhibited in a dose-dependent manner, when the carcinoma cells were exposed to OK-432. Cell attachment assay demonstrated that incubation with OK-432 for 24 h reduced integrin-mediated cellular adhesion of both cell types. However, fluorescence activated cell sorter (FACS) analysis revealed that incubation with OK-432 for 24 h did not decrease the cell surface expressions of any integrins. These results suggest that the binding avidity of integrins is reduced by OK-432 without alteration of the integrin expression. We conclude that OK-432 inhibits integrin-mediated cellular adhesion as well as cell proliferation of breast carcinoma cells regardless of estrogen-dependence, and that these actions of OK-432 contribute to prevention or inhibition of breast carcinoma invasion and metastasis.

  3. CRF2 signaling is a novel regulator of cellular adhesion and migration in colorectal cancer cells.

    Science.gov (United States)

    Ducarouge, Benjamin; Pelissier-Rota, Marjolaine; Lainé, Michèle; Cristina, Nadine; Vachez, Yvan; Scoazec, Jean-Yves; Bonaz, Bruno; Jacquier-Sarlin, Muriel

    2013-01-01

    Stress has been proposed to be a tumor promoting factor through the secretion of specific neuromediators, such as Urocortin2 and 3 (Ucn2/3), however its role in colorectal cancer (CRC) remains elusive. We observed that Ucn2/3 and their receptor the Corticotropin Releasing Factor receptor 2 (CRF2) were up-regulated in high grade and poorly differentiated CRC. This suggests a role for CRF2 in the loss of cellular organization and tumor progression. Using HT-29 and SW620 cells, two CRC cell lines differing in their abilities to perform cell-cell contacts, we found that CRF2 signals through Src/ERK pathway to induce the alteration of cell-cell junctions and the shuttle of p120ctn and Kaiso in the nucleus. In HT-29 cells, this signaling pathway also leads to the remodeling of cell adhesion by i) the phosphorylation of Focal Adhesion Kinase and ii) a modification of actin cytoskeleton and focal adhesion complexes. These events stimulate cell migration and invasion. In conclusion, our findings indicate that CRF2 signaling controls cellular organization and may promote metastatic potential of human CRC cells through an epithelial-mesenchymal transition like process. This contributes to the comprehension of the tumor-promoting effects of stress molecules and designates Ucn2/3-CRF2 tandem as a target to prevent CRC progression and aggressiveness.

  4. Adhesion and migration of CHO cells on micropatterned single layer graphene

    Science.gov (United States)

    Keshavan, S.; Oropesa-Nuñez, R.; Diaspro, A.; Canale, C.; Dante, S.

    2017-06-01

    Cell patterning technology on single layer graphene (SLG) is a fairly new field that can find applications in tissue engineering and biomaterial/biosensors development. Recently, we have developed a simple and effective approach for the fabrication of patterned SLG substrates by laser micromachining, and we have successfully applied it for the obtainment of geometrically ordered neural networks. Here, we exploit the same approach to investigate the generalization of the cell response to the surface cues of the fabricated substrates and, contextually, to quantify cell adhesion on the different areas of the patterns. To attain this goal, we tested Chinese hamster ovary (CHO) cells on PDL-coated micropatterned SLG substrates and quantified the adhesion by using single cell force spectroscopy (SCFS). Our results indicate higher cell adhesion on PDL-SLG, and, consequently, an initial CHO cell accumulation on the graphene areas, confirming the neuronal behaviour observed previously; interestingly, at later time point in culture, cell migration was observed towards the adjacent SLG ablated regions, which resulted more favourable for cell proliferation. Therefore, our findings indicate that the mechanism of interaction with the surface cues offered by the micropatterned substrates is strictly cell-type dependent.

  5. The synaptic cell adhesion molecule, SynCAM1, mediates astrocyte-to-astrocyte and astrocyte-to-GnRH neuron adhesiveness in the mouse hypothalamus.

    Science.gov (United States)

    Sandau, Ursula S; Mungenast, Alison E; McCarthy, Jack; Biederer, Thomas; Corfas, Gabriel; Ojeda, Sergio R

    2011-06-01

    We previously identified synaptic cell adhesion molecule 1 (SynCAM1) as a component of a genetic network involved in the hypothalamic control of female puberty. Although it is well established that SynCAM1 is a synaptic adhesion molecule, its contribution to hypothalamic function is unknown. Here we show that, in addition to the expected neuronal localization illustrated by its presence in GnRH neurons, SynCAM1 is expressed in hypothalamic astrocytes. Cell adhesion assays indicated that SynCAM is recognized by both GnRH neurons and astrocytes as an adhesive partner and promotes cell-cell adhesiveness via homophilic, extracellular domain-mediated interactions. Alternative splicing of the SynCAM1 primary mRNA transcript yields four mRNAs encoding membrane-spanning SynCAM1 isoforms. Variants 1 and 4 are predicted to be both N and O glycosylated. Hypothalamic astrocytes and GnRH-producing GT1-7 cells express mainly isoform 4 mRNA, and sequential N- and O-deglycosylation of proteins extracted from these cells yields progressively smaller SynCAM1 species, indicating that isoform 4 is the predominant SynCAM1 variant expressed in astrocytes and GT1-7 cells. Neither cell type expresses the products of two other SynCAM genes (SynCAM2 and SynCAM3), suggesting that SynCAM-mediated astrocyte-astrocyte and astrocyte-GnRH neuron adhesiveness is mostly mediated by SynCAM1 homophilic interactions. When erbB4 receptor function is disrupted in astrocytes, via transgenic expression of a dominant-negative erbB4 receptor form, SynCAM1-mediated adhesiveness is severely compromised. Conversely, SynCAM1 adhesive behavior is rapidly, but transiently, enhanced in astrocytes by ligand-dependent activation of erbB4 receptors, suggesting that erbB4-mediated events affecting SynCAM1 function contribute to regulate astrocyte adhesive communication.

  6. Establishing contact between cell-laden hydrogels and metallic implants with a biomimetic adhesive for cell therapy supported implants.

    Science.gov (United States)

    Barthes, Julien; Mutschler, Angela; Dollinger, Camille; Gaudinat, Guillaume; Lavalle, Philippe; Le Houerou, Vincent; Brian McGuinness, Garrett; Engin Vrana, Nihal

    2017-12-15

    For in-dwelling implants, controlling the biological interface is a crucial parameter to promote tissue integration and prevent implant failure. For this purpose, one possibility is to facilitate the establishment of the interface with cell-laden hydrogels fixed to the implant. However, for proper functioning, the stability of the hydrogel on the implant should be ensured. Modification of implant surfaces with an adhesive represents a promising strategy to promote the adhesion of a cell-laden hydrogel on an implant. Herein, we developed a peptidic adhesive based on mussel foot protein (L-DOPA-L-lysine) 2 -L-DOPA that can be applied directly on the surface of an implant. At physiological pH, unoxidized (L-DOPA-L-lysine) 2 -L-DOPA was supposed to strongly adhere to metallic surfaces but it only formed a very thin coating (less than 1 nm). Once oxidized at physiological pH, (L-DOPA-L-lysine) 2 -L-DOPA forms an adhesive coating about 20 nm thick. In oxidized conditions, L-lysine can adhere to metallic substrates via electrostatic interaction. Oxidized L-DOPA allows the formation of a coating through self-polymerization and can react with amines so that this adhesive can be used to fix extra-cellular matrix based materials on implant surfaces through the reaction of quinones with amino groups. Hence, a stable interface between a soft gelatin hydrogel and metallic surfaces was achieved and the strength of adhesion was investigated. We have shown that the adhesive is non-cytotoxic to encapsulated cells and enabled the adhesion of gelatin soft hydrogels for 21 days on metallic substrates in liquid conditions. The adhesion properties of this anchoring peptide was quantified by a 180° peeling test with a more than 60% increase in peel strength in the presence of the adhesive. We demonstrated that by using a biomimetic adhesive, for the application of cell-laden hydrogels to metallic implant surfaces, the hydrogel/implant interface can be ensured without relying on the

  7. Tailored Poly(2-oxazoline) Polymer Brushes to Control Protein Adsorption and Cell Adhesion

    KAUST Repository

    Zhang, Ning; Pompe, Tilo; Amin, Ihsan; Luxenhofer, Robert; Werner, Carsten; Jordan, Rainer

    2012-01-01

    POx bottle-brush brushes (BBBs) are synthesized by SIPGP of 2-isopropenyl-2-oxazoline and consecutive LCROP of 2-oxazolines on 3-aminopropyltrimethoxysilane-modified silicon substrates. The side chain hydrophilicity and polarity are varied. The impact of the chemical composition and architecture of the BBB upon protein (fibronectin) adsorption and endothelial cell adhesion are investigated and prove extremely low protein adsorption and cell adhesion on BBBs with hydrophilic side chains such as poly(2-methyl-2-oxazoline) and poly(2-ethyl-2-oxazoline). The influence of the POx side chain terminal function upon adsorption and adhesion is minor but the side chain length has a significant effect on bioadsorption. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Tailored Poly(2-oxazoline) Polymer Brushes to Control Protein Adsorption and Cell Adhesion

    KAUST Repository

    Zhang, Ning

    2012-05-18

    POx bottle-brush brushes (BBBs) are synthesized by SIPGP of 2-isopropenyl-2-oxazoline and consecutive LCROP of 2-oxazolines on 3-aminopropyltrimethoxysilane-modified silicon substrates. The side chain hydrophilicity and polarity are varied. The impact of the chemical composition and architecture of the BBB upon protein (fibronectin) adsorption and endothelial cell adhesion are investigated and prove extremely low protein adsorption and cell adhesion on BBBs with hydrophilic side chains such as poly(2-methyl-2-oxazoline) and poly(2-ethyl-2-oxazoline). The influence of the POx side chain terminal function upon adsorption and adhesion is minor but the side chain length has a significant effect on bioadsorption. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Signaling through intercellular adhesion molecule 1 (ICAM-1) in a B cell lymphoma line

    DEFF Research Database (Denmark)

    Holland, J; Owens, T

    1997-01-01

    Intercellular adhesion molecule 1 (ICAM-1) (CD54) is an adhesion molecule of the immunoglobulin superfamily. The interaction between ICAM-1 on B lymphocytes and leukocyte function-associated antigen 1 on T cells plays a major role in several aspects of the immune response, including T-dependent B...... cell activation. While it was originally believed that ICAM-1 played a purely adhesive role, recent evidence suggests that it can itself transduce biochemical signals. We demonstrate that cross-linking of ICAM-1 results in the up-regulation of class II major histocompatibility complex, and we...... investigate the biochemical mechanism for the signaling role of ICAM-1. We show that cross-linking of ICAM-1 on the B lymphoma line A20 induces an increase in tyrosine phosphorylation of several cellular proteins, including the Src family kinase p53/p56(lyn). In vitro kinase assays showed that Lyn kinase...

  10. Single cell adhesion force measurement for cell viability identification using an AFM cantilever-based micro putter

    Science.gov (United States)

    Shen, Yajing; Nakajima, Masahiro; Kojima, Seiji; Homma, Michio; Kojima, Masaru; Fukuda, Toshio

    2011-11-01

    Fast and sensitive cell viability identification is a key point for single cell analysis. To address this issue, this paper reports a novel single cell viability identification method based on the measurement of single cell shear adhesion force using an atomic force microscopy (AFM) cantilever-based micro putter. Viable and nonviable yeast cells are prepared and put onto three kinds of substrate surfaces, i.e. tungsten probe, gold and ITO substrate surfaces. A micro putter is fabricated from the AFM cantilever by focused ion beam etching technique. The spring constant of the micro putter is calibrated using the nanomanipulation approach. The shear adhesion force between the single viable or nonviable cell and each substrate is measured using the micro putter based on the nanorobotic manipulation system inside an environmental scanning electron microscope. The adhesion force is calculated based on the deflection of the micro putter beam. The results show that the adhesion force of the viable cell to the substrate is much larger than that of the nonviable cell. This identification method is label free, fast, sensitive and can give quantitative results at the single cell level.

  11. Inhibition of PTP1B disrupts cell?cell adhesion and induces anoikis in breast epithelial cells

    OpenAIRE

    Hilmarsdottir, Bylgja; Briem, Eirikur; Halldorsson, Skarphedinn; Kricker, Jennifer; Ingthorsson, S?var; Gustafsdottir, Sigrun; M?landsmo, Gunhild M; Magnusson, Magnus K; Gudjonsson, Thorarinn

    2017-01-01

    Protein tyrosine phosphatase 1B (PTP1B) is a well-known inhibitor of insulin signaling pathways and inhibitors against PTP1B are being developed as promising drug candidates for treatment of obesity. PTP1B has also been linked to breast cancer both as a tumor suppressor and as an oncogene. Furthermore, PTP1B has been shown to be a regulator of cell adhesion and migration in normal and cancer cells. In this study, we analyzed the PTP1B expression in normal breast tissue, primary breast cells a...

  12. EMMPRIN regulates β1 integrin-mediated adhesion through Kindlin-3 in human melanoma cells.

    Science.gov (United States)

    Delyon, Julie; Khayati, Farah; Djaafri, Ibtissem; Podgorniak, Marie-Pierre; Sadoux, Aurélie; Setterblad, Niclas; Boutalbi, Zineb; Maouche, Kamel; Maskos, Uwe; Menashi, Suzanne; Lebbé, Céleste; Mourah, Samia

    2015-06-01

    EMMPRIN is known to promote tumor invasion through extracellular matrix (ECM) degradation. Here we report that EMMPRIN can regulate melanoma cell adhesion to the ECM through an interaction with β1 integrin involving kindlin-3. In this study, EMMPRIN knockdown in the human melanoma cell line M10 using siRNA decreased cell invasion and significantly increased cell adhesion and spreading. A morphological change from a round to a spread shape was observed associated with enhanced phalloidin-labelled actin staining. In situ proximity ligation assay and co-immunoprecipitation revealed that EMMPRIN silencing increased the interaction of β1 integrin with kindlin-3, a focal adhesion protein. This was associated with an increase in β1 integrin activation and a decrease in the phosphorylation of the downstream integrin kinase FAK. Moreover, the expression at both the transcript and protein level of kindlin-3 and of β1 integrin was inversely regulated by EMMPRIN. EMMPRIN did not regulate either talin expression or its interaction with β1 integrin. These results are consistent with our in vivo demonstration that EMMPRIN inhibition increased β1 integrin activation and its interaction with kindlin-3. To conclude, these findings reveal a new role of EMMPRIN in tumor cell migration through ß1 integrin/kindlin-3-mediated adhesion pathway. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  13. [Effect of Spatholobus suberctus on adhesion, invasion, migration and metastasis of melanoma cells].

    Science.gov (United States)

    Xu, Jian-Ya; Gu, Qin; Xia, Wei-Jun

    2010-10-01

    To study the effect of Spatholobus suberctus, a kind of Chinese Traditional Medicine which can dissolve the stasis by activating the blood circulation, on invasion, adhesion, migration and metastasis of B16-BL6 metastatic mouse melanoma cells and its mechanism. The proliferation, adhesion, invasion and migration capacity of B16-BL6 metastatic cells was evaluated by MTP assay, adhesion assay and reconstituted basement membrane invasion and migration assay in vitro respectively. Mouse spontaneous motility melanoma model was used to study the effect of Spatholobus suberctus on metastasis in vivo. At the highest innoxious concentration, the extracts of Spatholobus suberctus inhibited the adhesion and invasion capacity of B16-BL6 metastatic cells significantly. In the mouse spontaneous melanoma model, the lung metastatic nodes number and its volume were significantly decreased after continuously treated with the extracts of Spatholobus suberctu. The extracts of Spatholobus suberctu can inhibit the metastasis of of B16-BI6 metastatic mouse melanoma cells and its mechanism may be inhibiting the capability of B16-BL6 cells in adhering to the ECM and invading the basement membrane.

  14. Cell adhesion and spreading on polymer surfaces micropatterned by ion beams

    International Nuclear Information System (INIS)

    Satriano, C.; Carnazza, S.; Licciardello, A.; Guglielmino, S.; Marletta, G.

    2003-01-01

    The cell adhesion and spreading behavior on surfaces of poly(ethyleneterephtalate) and poly(hydroxymethylsiloxane) micropatterned by focused 15 keV Ga + beams has been studied. It has been found that while no modification in the cell adhesion process could be observed for unirradiated and irradiated areas on the patterned surfaces, in the case of polyhydroxymethylsiloxane the cell adhesion process is basically confined within the irradiated areas and a clear dependence of the cell ordering on the lateral size of the irradiated areas is observed. The results are discussed in terms of the specific spatially resolved chemical modification induced by Ga + irradiation onto the two different polymers. Thus, the irradiation-induced modification of composition, functional groups concentration, surface free energy, and nanoscale morphology have been studied by means of x-ray photoelectron spectroscopy, time-of-flight secondary ion mass spectrometry, contact angle, and atomic force microscopy. The cell adhesion and spreading behavior was found to nicely correlate with the increase of the acid-base component γ AB of the surface free energy and more particularly with the dramatic increase of the Lewis basic electron-donor term

  15. Cell adhesion to textured silicone surfaces : The influence of time of adhesion and texture on focal contact and fibronectin fibril formation

    NARCIS (Netherlands)

    van Kooten, TG; von Recum, AF

    Cell adhesion and spreading on biomaterials is a key issue in the study of cell-biomaterial interactions. With the development of new disciplines within biomaterials research such as tissue engineering and cellular therapy, information at molecular and structural levels is needed in order to

  16. Priming by Chemokines Restricts Lateral Mobility of the Adhesion Receptor LFA-1 and Restores Adhesion to ICAM-1 Nano-Aggregates on Human Mature Dendritic Cells

    NARCIS (Netherlands)

    Borgman, K.J.; van Zanten, T.S.; Manzo, C.; Cabezon, R.; Cambi, A.; Benitez-Ribas, D.; Garcia Parajo, M.F.

    2014-01-01

    LFA-1 is a leukocyte specific β2 integrin that plays a major role in regulating adhesion and migration of different immune cells. Recent data suggest that LFA-1 on mature dendritic cells (mDCs) may function as a chemokine-inducible anchor during homing of DCs through the afferent lymphatics into the

  17. Circulating vascular cell adhesion molecule-1 in pre-eclampsia, gestational hypertension, and normal pregnancy: evidence of selective dysregulation of vascular cell adhesion molecule-1 homeostasis in pre-eclampsia.

    Science.gov (United States)

    Higgins, J R; Papayianni, A; Brady, H R; Darling, M R; Walshe, J J

    1998-08-01

    Our purpose was to investigate circulating levels of vascular cell adhesion molecule-1 in the peripheral and uteroplacental circulations during normotensive and hypertensive pregnancies. This prospective observational study involved 2 patient groups. Group 1 consisted of 22 women with pre-eclampsia and 30 normotensive women followed up longitudinally through pregnancy and post partum. There were an additional 13 women with established gestational hypertension. Group 2 consisted of 20 women with established pre-eclampsia and 19 normotensive control subjects undergoing cesarean delivery. Plasma levels of vascular cell adhesion molecule-1 were measured in blood drawn from the antecubital vein (group 1) and from both the antecubital and uterine veins (group 2). Data were analyzed by analysis of variance. In group 1 vascular cell adhesion molecule-1 levels did not change significantly throughout normal pregnancy and post partum. Women with established pre-eclampsia had increased vascular cell adhesion molecule-1 levels compared with the normotensive pregnancy group (P = .01). Vascular cell adhesion molecule-1 levels were not elevated in women with established gestational hypertension. In group 2 significantly higher levels of vascular cell adhesion molecule-1 were detected in the uteroplacental (P post partum, is not a feature of nonproteinuric gestational hypertension, and is not observed with other major leukocyte adhesion molecules. Induction of vascular cell adhesion molecule-1 expression in pre-eclampsia may contribute to leukocyte-mediated tissue injury in this condition or may reflect perturbation of other, previously unrecognized, functions of this molecule in pregnancy.

  18. Angiogenin enhances cell migration by regulating stress fiber assembly and focal adhesion dynamics.

    Directory of Open Access Journals (Sweden)

    Saisai Wei

    Full Text Available Angiogenin (ANG acts on both vascular endothelial cells and cancer cells, but the underlying mechanism remains elusive. In this study, we carried out a co-immunoprecipitation assay in HeLa cells and identified 14 potential ANG-interacting proteins. Among these proteins, β-actin, α-actinin 4, and non-muscle myosin heavy chain 9 are stress fiber components and involved in cytoskeleton organization and movement, which prompted us to investigate the mechanism of action of ANG in cell migration. Upon confirmation of the interactions between ANG and the three proteins, further studies revealed that ANG co-localized with β-actin and α-actinin 4 at the leading edge of migrating cells. Down-regulation of ANG resulted in fewer but thicker stress fibers with less dynamics, which was associated with the enlargements of focal adhesions. The focal adhesion kinase activity and cell migration capacity were significantly decreased in ANG-deficient cells. Taken together, our data demonstrated that the existence of ANG in the cytoplasm optimizes stress fiber assembly and focal adhesion formation to accommodate cell migration. The finding that ANG promoted cancer cell migration might provide new clues for tumor metastasis research.

  19. Tetraspanin CD9: A Key Regulator of Cell Adhesion in the Immune System

    Directory of Open Access Journals (Sweden)

    Raquel Reyes

    2018-04-01

    Full Text Available The tetraspanin CD9 is expressed by all the major subsets of leukocytes (B cells, CD4+ T cells, CD8+ T cells, natural killer cells, granulocytes, monocytes and macrophages, and immature and mature dendritic cells and also at a high level by endothelial cells. As a typical member of the tetraspanin superfamily, a prominent feature of CD9 is its propensity to engage in a multitude of interactions with other tetraspanins as well as with different transmembrane and intracellular proteins within the context of defined membranal domains termed tetraspanin-enriched microdomains (TEMs. Through these associations, CD9 influences many cellular activities in the different subtypes of leukocytes and in endothelial cells, including intracellular signaling, proliferation, activation, survival, migration, invasion, adhesion, and diapedesis. Several excellent reviews have already covered the topic of how tetraspanins, including CD9, regulate these cellular processes in the different cells of the immune system. In this mini-review, however, we will focus particularly on describing and discussing the regulatory effects exerted by CD9 on different adhesion molecules that play pivotal roles in the physiology of leukocytes and endothelial cells, with a particular emphasis in the regulation of adhesion molecules of the integrin and immunoglobulin superfamilies.

  20. Inhibition of PTP1B disrupts cell-cell adhesion and induces anoikis in breast epithelial cells.

    Science.gov (United States)

    Hilmarsdottir, Bylgja; Briem, Eirikur; Halldorsson, Skarphedinn; Kricker, Jennifer; Ingthorsson, Sævar; Gustafsdottir, Sigrun; Mælandsmo, Gunhild M; Magnusson, Magnus K; Gudjonsson, Thorarinn

    2017-05-11

    Protein tyrosine phosphatase 1B (PTP1B) is a well-known inhibitor of insulin signaling pathways and inhibitors against PTP1B are being developed as promising drug candidates for treatment of obesity. PTP1B has also been linked to breast cancer both as a tumor suppressor and as an oncogene. Furthermore, PTP1B has been shown to be a regulator of cell adhesion and migration in normal and cancer cells. In this study, we analyzed the PTP1B expression in normal breast tissue, primary breast cells and the breast epithelial cell line D492. In normal breast tissue and primary breast cells, PTP1B is widely expressed in both epithelial and stromal cells, with highest expression in myoepithelial cells and fibroblasts. PTP1B is widely expressed in branching structures generated by D492 when cultured in 3D reconstituted basement membrane (3D rBM). Inhibition of PTP1B in D492 and another mammary epithelial cell line HMLE resulted in reduced cell proliferation and induction of anoikis. These changes were seen when cells were cultured both in monolayer and in 3D rBM. PTP1B inhibition affected cell attachment, expression of cell adhesion proteins and actin polymerization. Moreover, epithelial to mesenchymal transition (EMT) sensitized cells to PTP1B inhibition. A mesenchymal sublines of D492 and HMLE (D492M and HMLEmes) were more sensitive to PTP1B inhibition than D492 and HMLE. Reversion of D492M to an epithelial state using miR-200c-141 restored resistance to detachment induced by PTP1B inhibition. In conclusion, we have shown that PTP1B is widely expressed in the human breast gland with highest expression in myoepithelial cells and fibroblasts. Inhibition of PTP1B in D492 and HMLE affects cell-cell adhesion and induces anoikis-like effects. Finally, cells with an EMT phenotype are more sensitive to PTP1B inhibitors making PTP1B a potential candidate for further studies as a target for drug development in cancer involving the EMT phenotype.

  1. Crystal structure of the Ig1 domain of the neural cell adhesion molecule NCAM2 displays domain swapping

    DEFF Research Database (Denmark)

    Rasmussen, Kim Krighaar; Kulahin, Nikolaj; Kristensen, Ole

    2008-01-01

    The crystal structure of the first immunoglobulin (Ig1) domain of neural cell adhesion molecule 2 (NCAM2/OCAM/RNCAM) is presented at a resolution of 2.7 A. NCAM2 is a member of the immunoglobulin superfamily of cell adhesion molecules (IgCAMs). In the structure, two Ig domains interact by domain...

  2. Biosynthesis of the D2 cell adhesion molecule: pulse-chase studies in cultured fetal rat neuronal cells

    DEFF Research Database (Denmark)

    Lyles, J M; Norrild, B; Bock, E

    1984-01-01

    D2 is a membrane glycoprotein that is believed to function as a cell adhesion molecule (CAM) in neural cells. We have examined its biosynthesis in cultured fetal rat brain neurones. We found D2-CAM to be synthesized initially as two polypeptides: Mr 186,000 (A) and Mr 136,000 (B). With increasing...

  3. Cell adhesion control by ion implantation into extra-cellular matrix

    International Nuclear Information System (INIS)

    Suzuki, Yoshiaki; Kusakabe, Masahiro; Kaibara, Makoto; Iwaki, Masaya; Sasabe, Hiroyuki; Nishisaka, Tsuyoshi

    1994-01-01

    Cell adhesion control of polymer surfaces by ion implantation into polymers and extra-cellular matrix has been studied by means of in vitro adhesion measurements of the carcinoma of the cervix (HeLa cell). The specimens used were polystyrene (PS), oxygen plasma treated polystyrene (PS-O), extra-cellular matrix (Collagen: Type I) coated polystyrene (PS-C), and gelatin coated polystyrene (PS-G). Ne + , Na + , and Ar + implantations were performed with a fluence of 1x10 15 ions/cm 2 at energies of 50, 100 and 150 keV. The chemical and physical structures of ion implanted specimens have been investigated by Fourier transform infrared spectroscopy (FT-IR-ATR), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. Ion implanted PS demonstrated a dramatic improvement of adhesion of HeLa cell. HeLa cell adhered only to ion implanted circular domains of a diameter about 0.1 mm on PS. By contrast, ion implanted PS-C, PS-G and PS-O domains inhibited the cell adhesion. These phenomena were observed on Ne + , Na + , and Ar + implanted specimens at energies of 50, 100, and 150 keV. Ion implantation broke the original chemical bonds to form new radicals such as =C=O, condensed rings, C-C, C-O and OH radical. Ion implanted PS had a large amount of new radicals compared with that of PS-C, PS-G and PS-O. Ion implantation broke NH and NH 3 bonds originating from amino acid in PS-C and PS-G. OH and =C=O caused by oxygen treatment in PS-O were also destroyed by ion implantation. It is concluded that cell adhesion to ion implanted PS was caused by carbon structure and new radicals induced by ion implantation. The inhibition of HeLa cell adhesion on PS-C, PS-G and PS-O was caused by the destruction of cell adhesion properties of amino acid, OH and =C=O by radiation effects. ((orig.))

  4. Role for Adhesion Molecules in the Spermatogonial Stem Cell Niche

    NARCIS (Netherlands)

    de Rooij, Dirk G.; Repping, S.; van Pelt, Ans M. M.

    2008-01-01

    In this issue of Cell Stem Cell, Kanatsu-Shinohara et al. (2008) show that beta 1-integrin participates in normal spermatogenesis and is required for spermatogonial stem cell (SSC) homing to the basal membrane niche. The methodology used provides a powerful tool to study the role of other factors in

  5. Hyaluronan suppresses prostate tumor cell proliferation through diminished expression of N-cadherin and aberrant growth factor receptor signaling

    International Nuclear Information System (INIS)

    Bharadwaj, Alamelu G.; Goodrich, Nathaniel P.; McAtee, Caitlin O.; Haferbier, Katie; Oakley, Gregory G.; Wahl, James K.; Simpson, Melanie A.

    2011-01-01

    Hyaluronan (HA) production has been functionally implicated in prostate tumorigenesis and metastasis. We previously used prostate tumor cells overexpressing the HA synthesizing enzyme HAS3 or the clinically relevant hyaluronidase Hyal1 to show that excess HA production suppresses tumor growth, while HA turnover accelerates spontaneous metastasis from the prostate. Here, we examined pathways responsible for effects of HAS3 and Hyal1 on tumor cell phenotype. Detailed characterization of cell cycle progression revealed that expression of Hyal1 accelerated cell cycle re-entry following synchronization, whereas HAS3 alone delayed entry. Hyal1 expressing cells exhibited a significant reduction in their ability to sustain ERK phosphorylation upon stimulation by growth factors, and in their expression of the cyclin-dependent kinase inhibitor p21. In contrast, HAS3 expressing cells showed prolonged ERK phosphorylation and increased expression of both p21 and p27, in asynchronous and synchronized cultures. Changes in cell cycle regulatory proteins were accompanied by HA-induced suppression of N-cadherin, while E-cadherin expression and β-catenin expression and distribution remained unchanged. Our results are consistent with a model in which excess HA synthesis suppresses cell proliferation by promoting homotypic E-cadherin mediated cell-cell adhesion, consequently signaling to elevate cell cycle inhibitor expression and suppress G1- to S-phase transition.

  6. Morphology and interdiffusion control to improve adhesion and cohesion properties in inverted polymer solar cells

    KAUST Repository

    Dupont, Stephanie R.; Voroshazi, Eszter; Nordlund, Dennis; Dauskardt, Reinhold H.

    2015-01-01

    © 2014 Elsevier B.V. All rights reserved. The role of pre-electrode deposition annealing on the morphology and the fracture properties of polymer solar cells is discussed. We found an increase in adhesion at the weak P3HT:PCBM/PEDOT:PSS interface

  7. Enhanced adhesion of osteoblastic cells on polystyrene films by independent control of surface topography and wettability

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Seung Yun [National Creative Research Center for Block Copolymer Self-Assembly, Departments of Environmental Science and Engineering and Chemical Engineering, Pohang University of Science and Technology, Pohang, 790-784 (Korea, Republic of); Kim, Eung-Sam [School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, Pohang, 790-784 (Korea, Republic of); Jeon, Gumhye [National Creative Research Center for Block Copolymer Self-Assembly, Departments of Environmental Science and Engineering and Chemical Engineering, Pohang University of Science and Technology, Pohang, 790-784 (Korea, Republic of); Choi, Kwan Yong, E-mail: kchoi@postech.ac.kr [School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, Pohang, 790-784 (Korea, Republic of); Department of Life Science, Division of Molecular and Life Science, Pohang University of Science and Technology, Pohang, 790-784 (Korea, Republic of); Kim, Jin Kon, E-mail: jkkim@postech.ac.kr [National Creative Research Center for Block Copolymer Self-Assembly, Departments of Environmental Science and Engineering and Chemical Engineering, Pohang University of Science and Technology, Pohang, 790-784 (Korea, Republic of)

    2013-04-01

    We independently controlled surface topography and wettability of polystyrene (PS) films by CF{sub 4} and oxygen plasma treatments, respectively, to evaluate the adhesion and proliferation of human fetal osteoblastic (hFOB) cells on the films. Among the CF{sub 4} plasma-treated PS films with the average surface roughness ranging from 0.9 to 70 nm, the highest adhesion of hFOB cells was observed on a PS film with roughness of ∼ 11 nm. When this film was additionally treated by oxygen plasma to provide a hydrophilic surface with a contact angle less than 10°, the proliferation of bone-forming cell was further enhanced. Thus, the plasma-based independent modification of PS film into an optimum nanotexture for human osteoblast cells could be appplied to materials used in bone tissue engineering. Highlights: ► New approach based on plasma treatment to independently control the surface topography and wettability ► The adhesion of human fetal osteoblast (hFOB) was enhanced on a surface with an average roughness of ∼ 11 nm. ► The adhesion and proliferation of hFOB was maximized when nanotextured surface became highly hydrophilic.

  8. Enhanced adhesion of osteoblastic cells on polystyrene films by independent control of surface topography and wettability

    International Nuclear Information System (INIS)

    Yang, Seung Yun; Kim, Eung-Sam; Jeon, Gumhye; Choi, Kwan Yong; Kim, Jin Kon

    2013-01-01

    We independently controlled surface topography and wettability of polystyrene (PS) films by CF 4 and oxygen plasma treatments, respectively, to evaluate the adhesion and proliferation of human fetal osteoblastic (hFOB) cells on the films. Among the CF 4 plasma-treated PS films with the average surface roughness ranging from 0.9 to 70 nm, the highest adhesion of hFOB cells was observed on a PS film with roughness of ∼ 11 nm. When this film was additionally treated by oxygen plasma to provide a hydrophilic surface with a contact angle less than 10°, the proliferation of bone-forming cell was further enhanced. Thus, the plasma-based independent modification of PS film into an optimum nanotexture for human osteoblast cells could be appplied to materials used in bone tissue engineering. Highlights: ► New approach based on plasma treatment to independently control the surface topography and wettability ► The adhesion of human fetal osteoblast (hFOB) was enhanced on a surface with an average roughness of ∼ 11 nm. ► The adhesion and proliferation of hFOB was maximized when nanotextured surface became highly hydrophilic

  9. Modeling the formation of cell-matrix adhesions on a single 3D matrix fiber.

    Science.gov (United States)

    Escribano, J; Sánchez, M T; García-Aznar, J M

    2015-11-07

    Cell-matrix adhesions are crucial in different biological processes like tissue morphogenesis, cell motility, and extracellular matrix remodeling. These interactions that link cell cytoskeleton and matrix fibers are built through protein clutches, generally known as adhesion complexes. The adhesion formation process has been deeply studied in two-dimensional (2D) cases; however, the knowledge is limited for three-dimensional (3D) cases. In this work, we simulate different local extracellular matrix properties in order to unravel the fundamental mechanisms that regulate the formation of cell-matrix adhesions in 3D. We aim to study the mechanical interaction of these biological structures through a three dimensional discrete approach, reproducing the transmission pattern force between the cytoskeleton and a single extracellular matrix fiber. This numerical model provides a discrete analysis of the proteins involved including spatial distribution, interaction between them, and study of the different phenomena, such as protein clutches unbinding or protein unfolding. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Cell Adhesion Molecule CD166/ALCAM Functions Within the Crypt to Orchestrate Murine Intestinal Stem Cell HomeostasisSummary

    Directory of Open Access Journals (Sweden)

    Nicholas R. Smith

    2017-05-01

    Full Text Available Background & Aims: Intestinal epithelial homeostasis is maintained by active-cycling and slow-cycling stem cells confined within an instructive crypt-based niche. Exquisite regulating of these stem cell populations along the proliferation-to-differentiation axis maintains a homeostatic balance to prevent hyperproliferation and cancer. Although recent studies focus on how secreted ligands from mesenchymal and epithelial populations regulate intestinal stem cells (ISCs, it remains unclear what role cell adhesion plays in shaping the regulatory niche. Previously we have shown that the cell adhesion molecule and cancer stem cell marker, CD166/ALCAM (activated leukocyte cell adhesion molecule, is highly expressed by both active-cycling Lgr5+ ISCs and adjacent Paneth cells within the crypt base, supporting the hypothesis that CD166 functions to mediate ISC maintenance and signal coordination. Methods: Here we tested this hypothesis by analyzing a CD166–/– mouse combined with immunohistochemical, flow cytometry, gene expression, and enteroid culture. Results: We found that animals lacking CD166 expression harbored fewer active-cycling Lgr5+ ISCs. Homeostasis was maintained by expansion of the transit-amplifying compartment and not by slow-cycling Bmi1+ ISC stimulation. Loss of active-cycling ISCs was coupled with deregulated Paneth cell homeostasis, manifested as increased numbers of immature Paneth progenitors due to decreased terminal differentiation, linked to defective Wnt signaling. CD166–/– Paneth cells expressed reduced Wnt3 ligand expression and depleted nuclear β-catenin. Conclusions: These data support a function for CD166 as an important cell adhesion molecule that shapes the signaling microenvironment by mediating ISC–niche cell interactions. Furthermore, loss of CD166 expression results in decreased ISC and Paneth cell homeostasis and an altered Wnt microenvironment. Keywords: Intestinal Stem Cell, Homeostasis

  11. Candida albicans Hom6 is a homoserine dehydrogenase involved in protein synthesis and cell adhesion

    Directory of Open Access Journals (Sweden)

    Pei-Wen Tsai

    2017-12-01

    Full Text Available Background/Purpose: Candida albicans is a common fungal pathogen in humans. In healthy individuals, C. albicans represents a harmless commensal organism, but infections can be life threatening in immunocompromised patients. The complete genome sequence of C. albicans is extremely useful for identifying genes that may be potential drug targets and important for pathogenic virulence. However, there are still many uncharacterized genes in the Candida genome database. In this study, we investigated C. albicans Hom6, the functions of which remain undetermined experimentally. Methods: HOM6-deleted and HOM6-reintegrated mutant strains were constructed. The mutant strains were compared with wild-type in their growth in various media and enzyme activity. Effects of HOM6 deletion on translation were further investigated by cell susceptibility to hygromycin B or cycloheximide, as well as by polysome profiling, and cell adhesion to polystyrene was also determined. Results: C. albicans Hom6 exhibits homoserine dehydrogenase activity and is involved in the biosynthesis of methionine and threonine. HOM6 deletion caused translational arrest in cells grown under amino acid starvation conditions. Additionally, Hom6 protein was found in both cytosolic and cell-wall fractions of cultured cells. Furthermore, HOM6 deletion reduced C. albicans cell adhesion to polystyrene, which is a common plastic used in many medical devices. Conclusion: Given that there is no Hom6 homologue in mammalian cells, our results provided an important foundation for future development of new antifungal drugs. Keywords: Candida albicans, cell adhesion, Hom6, homoserine dehydrogenase, protein synthesis

  12. Collective epithelial cell sheet adhesion and migration on polyelectrolyte multilayers with uniform and gradients of compliance

    International Nuclear Information System (INIS)

    Martinez, Jessica S.; Schlenoff, Joseph B.; Keller, Thomas C.S.

    2016-01-01

    Polyelectrolyte multilayers (PEMUs) are tunable thin films that could serve as coatings for biomedical implants. PEMUs built layer by layer with the polyanion poly(acrylic acid) (PAA) modified with a photosensitive 4-(2-hydroxyethoxy) benzophenone (PAABp) group and the polycation poly(allylamine hydrochloride) (PAH) are mechanically tunable by UV irradiation, which forms covalent bonds between the layers and increases PEMU stiffness. PAH-terminated PEMUs (PAH-PEMUs) that were uncrosslinked, UV-crosslinked to a uniform stiffness, or UV-crosslinked with an edge mask or through a neutral density optical gradient filter to form continuous compliance gradients were used to investigate how differences in PEMU stiffness affect the adhesion and migration of epithelial cell sheets from scales of the fish Poecilia sphenops (Black Molly) and Carassius auratus (Comet Goldfish). During the progressive collective cell migration, the edge cells (also known as ‘leader’ cells) in the sheets on softer uncrosslinked PEMUs and less crosslinked regions of the gradient formed more actin filaments and vinculin-containing adherens junctions and focal adhesions than formed in the sheet cells on stiffer PEMUs or glass. During sheet migration, the ratio of edge cell to internal cell (also known as ‘follower’ cells) motilities were greater on the softer PEMUs than on the stiffer PEMUs or glass, causing tension to develop across the sheet and periods of retraction, during which the edge cells lost adhesion to the substrate and regions of the sheet retracted toward the more adherent internal cell region. These retraction events were inhibited by the myosin II inhibitor Blebbistatin, which reduced the motility velocity ratios to those for sheets on the stiffer PEMUs. Blebbistatin also caused disassembly of actin filaments, reorganization of focal adhesions, increased cell spreading at the leading edge, as well as loss of edge cell-cell connections in epithelial cell sheets on all

  13. Collective epithelial cell sheet adhesion and migration on polyelectrolyte multilayers with uniform and gradients of compliance

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, Jessica S. [Department of Biological Science, Florida State University, Tallahassee, FL 32306 (United States); Schlenoff, Joseph B. [Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL 32306 (United States); Keller, Thomas C.S., E-mail: tkeller@bio.fsu.edu [Department of Biological Science, Florida State University, Tallahassee, FL 32306 (United States)

    2016-08-01

    Polyelectrolyte multilayers (PEMUs) are tunable thin films that could serve as coatings for biomedical implants. PEMUs built layer by layer with the polyanion poly(acrylic acid) (PAA) modified with a photosensitive 4-(2-hydroxyethoxy) benzophenone (PAABp) group and the polycation poly(allylamine hydrochloride) (PAH) are mechanically tunable by UV irradiation, which forms covalent bonds between the layers and increases PEMU stiffness. PAH-terminated PEMUs (PAH-PEMUs) that were uncrosslinked, UV-crosslinked to a uniform stiffness, or UV-crosslinked with an edge mask or through a neutral density optical gradient filter to form continuous compliance gradients were used to investigate how differences in PEMU stiffness affect the adhesion and migration of epithelial cell sheets from scales of the fish Poecilia sphenops (Black Molly) and Carassius auratus (Comet Goldfish). During the progressive collective cell migration, the edge cells (also known as ‘leader’ cells) in the sheets on softer uncrosslinked PEMUs and less crosslinked regions of the gradient formed more actin filaments and vinculin-containing adherens junctions and focal adhesions than formed in the sheet cells on stiffer PEMUs or glass. During sheet migration, the ratio of edge cell to internal cell (also known as ‘follower’ cells) motilities were greater on the softer PEMUs than on the stiffer PEMUs or glass, causing tension to develop across the sheet and periods of retraction, during which the edge cells lost adhesion to the substrate and regions of the sheet retracted toward the more adherent internal cell region. These retraction events were inhibited by the myosin II inhibitor Blebbistatin, which reduced the motility velocity ratios to those for sheets on the stiffer PEMUs. Blebbistatin also caused disassembly of actin filaments, reorganization of focal adhesions, increased cell spreading at the leading edge, as well as loss of edge cell-cell connections in epithelial cell sheets on all

  14. Altered cell wall disassembly during ripening of Cnr tomato fruit: implications for cell adhesion and fruit softening

    DEFF Research Database (Denmark)

    Orfila, C.; Huisman, M.M.H.; Willats, William George Tycho

    2002-01-01

    The Cnr (Colourless non-ripening) tomato (Lycopersicon esculentum Mill.) mutant has an aberrant fruit-ripening phenotype in which fruit do not soften and have reduced cell adhesion between pericarp cells. Cell walls from Cnr fruit were analysed in order to assess the possible contribution of pectic...... polysaccharides to the non-softening and altered cell adhesion phenotype. Cell wall material (CWM) and solubilised fractions of mature green and red ripe fruit were analysed by chemical, enzymatic and immunochemical techniques. No major differences in CWM sugar composition were detected although differences were...... that was chelator-soluble was 50% less in Cnr cell walls at both the mature green and red ripe stages. Chelator-soluble material from ripe-stage Cnr was more susceptible to endo-polygalacturonase degradation than the corresponding material from wild-type fruit. In addition, cell walls from Cnr fruit contained...

  15. Localized Modeling of Biochemical and Flow Interactions during Cancer Cell Adhesion.

    Directory of Open Access Journals (Sweden)

    Julie Behr

    Full Text Available This work focuses on one component of a larger research effort to develop a simulation tool to model populations of flowing cells. Specifically, in this study a local model of the biochemical interactions between circulating melanoma tumor cells (TC and substrate adherent polymorphonuclear neutrophils (PMN is developed. This model provides realistic three-dimensional distributions of bond formation and attendant attraction and repulsion forces that are consistent with the time dependent Computational Fluid Dynamics (CFD framework of the full system model which accounts local pressure, shear and repulsion forces. The resulting full dynamics model enables exploration of TC adhesion to adherent PMNs, which is a known participating mechanism in melanoma cell metastasis. The model defines the adhesion molecules present on the TC and PMN cell surfaces, and calculates their interactions as the melanoma cell flows past the PMN. Biochemical rates of reactions between individual molecules are determined based on their local properties. The melanoma cell in the model expresses ICAM-1 molecules on its surface, and the PMN expresses the β-2 integrins LFA-1 and Mac-1. In this work the PMN is fixed to the substrate and is assumed fully rigid and of a prescribed shear-rate dependent shape obtained from micro-PIV experiments. The melanoma cell is transported with full six-degrees-of-freedom dynamics. Adhesion models, which represent the ability of molecules to bond and adhere the cells to each other, and repulsion models, which represent the various physical mechanisms of cellular repulsion, are incorporated with the CFD solver. All models are general enough to allow for future extensions, including arbitrary adhesion molecule types, and the ability to redefine the values of parameters to represent various cell types. The model presented in this study will be part of a clinical tool for development of personalized medical treatment programs.

  16. The Role of Titanium Surface Microtopography on Adhesion, Proliferation, Transformation, and Matrix Deposition of Corneal Cells.

    Science.gov (United States)

    Zhou, Chengxin; Lei, Fengyang; Chodosh, James; Paschalis, Eleftherios I

    2016-04-01

    Titanium (Ti) is an excellent implantable biomaterial that can be further enhanced by surface topography optimization. Despite numerous data from orthopedics and dentistry, the effect of Ti surface topography on ocular cells is still poorly understood. In light of the recent adaptation of Ti in the Boston Keratoprosthesis artificial cornea, we attempted to perform an extended evaluation of the effect of Ti surface topography on corneal cell adhesion, proliferation, cytotoxicity, transformation, and matrix deposition. Different surface topographies were generated on medical grade Ti-6Al-4V-ELI (extra-low interstitial), with linearly increased roughness (polished to grit blasted). Biological response was evaluated in vitro using human corneal limbal epithelial (HCLE) cells, stromal fibroblasts (HCF), and endothelial cells (HCEnC). None of the Ti surface topographies caused cytotoxicity to any of the three corneal cell types. However, rough Ti surface inhibited HCLE and HCF cell adhesion and proliferation, while HCEnC proliferation was unaffected. Long-term experiments with HCF revealed that rough Ti surface with R(a) (the arithmetic average of the profile height from the mean line) ≥ 1.15 μm suppressed HCF focal adhesion kinase phosphorylation, changed fibroblast morphology, and caused less aligned and reduced deposition of collagen matrix as compared to smooth Ti (R(a) ≤ 0.08 μm). In the presence of transforming growth factor β1 (TGFβ1) stimulation, rough Ti inhibited alpha-smooth muscle actin (α-SMA) expression and collagen deposition, leading to decreased myofibroblast transformation and disorganization of the collagen fibrils as compared to smooth Ti. This study suggests that Ti surface topography regulates corneal cell behavior in a tissue-dependent manner that varies across the corneal strata. Contrary to the accepted paradigm, smooth surface topography can enhance cell adhesion and proliferation and increase matrix deposition by corneal cells.

  17. Localized Modeling of Biochemical and Flow Interactions during Cancer Cell Adhesion.

    Science.gov (United States)

    Behr, Julie; Gaskin, Byron; Fu, Changliang; Dong, Cheng; Kunz, Robert

    2015-01-01

    This work focuses on one component of a larger research effort to develop a simulation tool to model populations of flowing cells. Specifically, in this study a local model of the biochemical interactions between circulating melanoma tumor cells (TC) and substrate adherent polymorphonuclear neutrophils (PMN) is developed. This model provides realistic three-dimensional distributions of bond formation and attendant attraction and repulsion forces that are consistent with the time dependent Computational Fluid Dynamics (CFD) framework of the full system model which accounts local pressure, shear and repulsion forces. The resulting full dynamics model enables exploration of TC adhesion to adherent PMNs, which is a known participating mechanism in melanoma cell metastasis. The model defines the adhesion molecules present on the TC and PMN cell surfaces, and calculates their interactions as the melanoma cell flows past the PMN. Biochemical rates of reactions between individual molecules are determined based on their local properties. The melanoma cell in the model expresses ICAM-1 molecules on its surface, and the PMN expresses the β-2 integrins LFA-1 and Mac-1. In this work the PMN is fixed to the substrate and is assumed fully rigid and of a prescribed shear-rate dependent shape obtained from micro-PIV experiments. The melanoma cell is transported with full six-degrees-of-freedom dynamics. Adhesion models, which represent the ability of molecules to bond and adhere the cells to each other, and repulsion models, which represent the various physical mechanisms of cellular repulsion, are incorporated with the CFD solver. All models are general enough to allow for future extensions, including arbitrary adhesion molecule types, and the ability to redefine the values of parameters to represent various cell types. The model presented in this study will be part of a clinical tool for development of personalized medical treatment programs.

  18. Genetic analysis of beta1 integrin function: confirmed, new and revised roles for a crucial family of cell adhesion molecules

    DEFF Research Database (Denmark)

    Brakebusch, C; Hirsch, E; Potocnik, A

    1997-01-01

    Integrins are heterodimeric cell adhesion proteins connecting the extracellular matrix to the cytoskeleton and transmitting signals in both directions. These integrins are suggested to be involved in many different biological processes such as growth, differentiation, migration, and cell death. O...

  19. Silk-based biomaterials functionalized with fibronectin type II promotes cell adhesion.

    Science.gov (United States)

    Pereira, Ana Margarida; Machado, Raul; da Costa, André; Ribeiro, Artur; Collins, Tony; Gomes, Andreia C; Leonor, Isabel B; Kaplan, David L; Reis, Rui L; Casal, Margarida

    2017-01-01

    The objective of this work was to exploit the fibronectin type II (FNII) module from human matrix metalloproteinase-2 as a functional domain for the development of silk-based biopolymer blends that display enhanced cell adhesion properties. The DNA sequence of spider dragline silk protein (6mer) was genetically fused with the FNII coding sequence and expressed in Escherichia coli. The chimeric protein 6mer+FNII was purified by non-chromatographic methods. Films prepared from 6mer+FNII by solvent casting promoted only limited cell adhesion of human skin fibroblasts. However, the performance of the material in terms of cell adhesion was significantly improved when 6mer+FNII was combined with a silk-elastin-like protein in a concentration-dependent behavior. With this work we describe a novel class of biopolymer that promote cell adhesion and potentially useful as biomaterials for tissue engineering and regenerative medicine. This work reports the development of biocompatible silk-based composites with enhanced cell adhesion properties suitable for biomedical applications in regenerative medicine. The biocomposites were produced by combining a genetically engineered silk-elastin-like protein with a genetically engineered spider-silk-based polypeptide carrying the three domains of the fibronectin type II module from human metalloproteinase-2. These composites were processed into free-standing films by solvent casting and characterized for their biological behavior. To our knowledge this is the first report of the exploitation of all three FNII domains as a functional domain for the development of bioinspired materials with improved biological performance. The present study highlights the potential of using genetically engineered protein-based composites as a platform for the development of new bioinspired biomaterials. Copyright © 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  20. Adhesion modification of neural stem cells induced by nanoscale ripple patterns

    International Nuclear Information System (INIS)

    Pedraz, P; Casado, S; Rodriguez, V; Ayuso-Sacido, A; Gnecco, E; Giordano, M C; Mongeot, F Buatier de

    2016-01-01

    We have studied the influence of anisotropic nanopatterns (ripples) on the adhesion and morphology of mouse neural stem cells (C17.2) on glass substrates using cell viability assay, optical microscopy and atomic force microscopy. The ripples were produced by defocused ion beam sputtering with inert Ar ions, which physically remove atoms from the surface at the energy of 800 eV. The ripple periodicity (∼200 nm) is comparable to the thickness of the cytoplasmatic microspikes (filopodia) which link the stem cells to the substrate. All methods show that the cell adhesion is significantly lowered compared to the same type of cells on flat glass surfaces. Furthermore, the AFM analysis reveals that the filopodia tend to be trapped parallel or perpendicular to the ripples, which limits the spreading of the stem cell on the rippled substrate. This opens the perspective of controlling the micro-adhesion of stem cells and the orientation of their filopodia by tuning the anisotropic substrate morphology without chemical reactions occurring at the surface. (paper)

  1. Lymphocyte adhesion to endothelial cell (EC) is stimulated by phorbol esters

    International Nuclear Information System (INIS)

    Haskard, D.; Cavender, D.; Ziff, M.

    1986-01-01

    The effect of phorbol esters on T cell adhesion to EC has been studied. The phorbol esters 12-0-tetradecanoyl-phorbol-13-acetate and 4-beta-phorbol-12-13-dibutyrate, but not the biologically inert 4-0-methyl-phorbol-12-13-didecanoate strongly increased the binding of 51 Cr-labeled T cells to human umbilical vein EC monolayers in microtiter wells. Increase in binding was observed at 0.3 ng/ml with maximal enhancement at 50 ng/ml. Both unstimulated and phorbol ester activated T cells displayed a substantially greater binding affinity for EC than for fibroblasts or plastic. Binding enhancement occurred within one minute, with maximal increase after 15 min. Preincubation studies showed that binding enhancement was entirely attributable to an effect on T cells, with no action on EC. Additive binding enhancement was seen when phorbol esters and reagents that increase adhesion by actions on EC (LPS, IL-1 and IFN-γ) were used together. Increase in adhesion of activated T lymphocytes to EC may explain the greater emigration of activated T cells than small resting T cells into inflammatory foci in vivo. The rapid onset of the phorbol effect suggests that this may be an important mechanism for immediate localization of circulating T cells in the cellular immune response, activated, perhaps, at the endothelial blood-tissue interface

  2. Label-free investigation of the effects of lithium niobate polarization on cell adhesion

    Science.gov (United States)

    Mandracchia, B.; Gennari, O.; Paturzo, M.; Grilli, S.; Ferraro, P.

    2017-06-01

    The determination of contact area is pivotal to understand how biomaterials properties influence cell adhesion. In particular, the influence of surface charges is well-known but still controversial, especially when new functional materials and methods are introduced. Here, we use for the first time Holographic Total Internal Reflection Microscopy (HoloTIRM) to study the influence of the spontaneous polarization of ferroelectric lithium niobate (LN) on the adhesion properties of fibroblast cells. The selective illumination of a very thin region directly above the substrate, achieved by Total Internal Reflection, provides high-contrast images of the contact regions. Holographic recording, on the other hand, allows for label-free quantitative phase imaging of the contact areas between cells and LN. Phase signal is more sensitive in the first 100nm and, thus more reliable in order to locate focal contacts. This work shows that cells adhering on negatively polarized LN present a significant increase of the contact area in comparison with cells adhering on the positively polarized LN substrate, as well as an intensification of contact vicinity. This confirms the potential of LN as a platform for investigating the role of charges on cellular processes. The similarity of cell adhesion behavior on negatively polarized LN and glass control also confirms the possibility to use LN as an active substrate without impairing cell behavior.

  3. Counterbalancing anti-adhesive effects of Tenascin-C through fibronectin expression in endothelial cells.

    Science.gov (United States)

    Radwanska, Agata; Grall, Dominique; Schaub, Sébastien; Divonne, Stéphanie Beghelli-de la Forest; Ciais, Delphine; Rekima, Samah; Rupp, Tristan; Sudaka, Anne; Orend, Gertraud; Van Obberghen-Schilling, Ellen

    2017-10-06

    Cellular fibronectin (FN) and tenascin-C (TNC) are prominent development- and disease-associated matrix components with pro- and anti-adhesive activity, respectively. Whereas both are present in the tumour vasculature, their functional interplay on vascular endothelial cells remains unclear. We have previously shown that basally-oriented deposition of a FN matrix restricts motility and promotes junctional stability in cultured endothelial cells and that this effect is tightly coupled to expression of FN. Here we report that TNC induces FN expression in endothelial cells. This effect counteracts the potent anti-adhesive activity of TNC and leads to the assembly of a dense highly-branched subendothelial matrix that enhances tubulogenic activity. These findings suggest that pro-angiogenic remodelling of the perivascular matrix may involve TNC-induced upregulation of FN in endothelial cells.

  4. Enhanced adhesion of osteoblastic cells on polystyrene films by independent control of surface topography and wettability.

    Science.gov (United States)

    Yang, Seung Yun; Kim, Eung-Sam; Jeon, Gumhye; Choi, Kwan Yong; Kim, Jin Kon

    2013-04-01

    We independently controlled surface topography and wettability of polystyrene (PS) films by CF4 and oxygen plasma treatments, respectively, to evaluate the adhesion and proliferation of human fetal osteoblastic (hFOB) cells on the films. Among the CF4 plasma-treated PS films with the average surface roughness ranging from 0.9 to 70 nm, the highest adhesion of hFOB cells was observed on a PS film with roughness of ~11 nm. When this film was additionally treated by oxygen plasma to provide a hydrophilic surface with a contact angle less than 10°, the proliferation of bone-forming cell was further enhanced. Thus, the plasma-based independent modification of PS film into an optimum nanotexture for human osteoblast cells could be appplied to materials used in bone tissue engineering. Copyright © 2012 Elsevier B.V. All rights reserved.

  5. Early adhesive behavior of bone-marrow-derived mesenchymal stem cells on collagen electrospun fibers

    Energy Technology Data Exchange (ETDEWEB)

    Chan, Casey K; Liao, Susan; Lareu, Ricky R; Raghunath, Michael [Division of Bioengineering, National University of Singapore, 7 Engineering Drive 1, Singapore 117574 (Singapore); Li, Bojun; Ramakrishna, S [Nanoscience and Nanotechnology Initiative, National University of Singapore, 2 Engineering Drive 3, Singapore 117576 (Singapore); Larrick, James W, E-mail: doschanc@nus.edu.s [Panorama Research Institute, 2462 Wyandotte Street, Mountain View, CA 94043 (United States)

    2009-06-15

    A bioabsorbable nanofibrous scaffold was developed for early adhesion of mesenchymal stem cells (MSCs). Collagen nanofibers with diameters of 430 +- 170 nm were fabricated by electrospinning. Over 45% of the MSC population adhered to this collagen nanofiber after 30 min at room temperature. Remarkably, collagen-coated P(LLA-CL) electrospun nanofibers were almost as efficient as collagen nanofibers whereas collagen cast film did not enhance early capture when it was applied on cover slips. The adhesive efficiency could be further increased to over 20% at 20 min and over 55% at 30 min when collagen nanofibers were grafted with monoclonal antibodies recognizing CD29 or CD49a. These data demonstrate that the early adhesive behavior is highly dependent on both the surface texture and the surface chemistry of the substrate. These findings have potential applications for early capture of MSCs in an ex vivo setting under time constraints such as in a surgical setting.

  6. Early adhesive behavior of bone-marrow-derived mesenchymal stem cells on collagen electrospun fibers

    International Nuclear Information System (INIS)

    Chan, Casey K; Liao, Susan; Lareu, Ricky R; Raghunath, Michael; Li, Bojun; Ramakrishna, S; Larrick, James W

    2009-01-01

    A bioabsorbable nanofibrous scaffold was developed for early adhesion of mesenchymal stem cells (MSCs). Collagen nanofibers with diameters of 430 ± 170 nm were fabricated by electrospinning. Over 45% of the MSC population adhered to this collagen nanofiber after 30 min at room temperature. Remarkably, collagen-coated P(LLA-CL) electrospun nanofibers were almost as efficient as collagen nanofibers whereas collagen cast film did not enhance early capture when it was applied on cover slips. The adhesive efficiency could be further increased to over 20% at 20 min and over 55% at 30 min when collagen nanofibers were grafted with monoclonal antibodies recognizing CD29 or CD49a. These data demonstrate that the early adhesive behavior is highly dependent on both the surface texture and the surface chemistry of the substrate. These findings have potential applications for early capture of MSCs in an ex vivo setting under time constraints such as in a surgical setting.

  7. [Cellular adhesion signal transduction network of tumor necrosis factor-alpha induced hepatocellular carcinoma cells].

    Science.gov (United States)

    Zheng, Yongchang; Du, Shunda; Xu, Haifeng; Xu, Yiyao; Zhao, Haitao; Chi, Tianyi; Lu, Xin; Sang, Xinting; Mao, Yilei

    2014-11-18

    To systemically explore the cellular adhesion signal transduction network of tumor necrosis factor-alpha (TNF-α)-induced hepatocellular carcinoma cells with bioinformatics tools. Published microarray dataset of TNF-α-induced HepG2, human transcription factor database HTRI and human protein-protein interaction database HPRD were used to construct and analyze the signal transduction network. In the signal transduction network, MYC and SP1 were the key nodes of signaling transduction. Several genes from the network were closely related with cellular adhesion.Epidermal growth factor receptor (EGFR) is a possible key gene of effectively regulating cellular adhesion during the induction of TNF-α. EGFR is a possible key gene for TNF-α-induced metastasis of hepatocellular carcinoma.

  8. Increasing mouse embryonic fibroblast cells adhesion on superhydrophilic vertically aligned carbon nanotube films

    Energy Technology Data Exchange (ETDEWEB)

    Lobo, A.O., E-mail: loboao@yahoo.com [Laboratory of Biomedical Nanotechnology (NanoBio), Instituto de Pesquisa e Desenvolvimento (IP and D), Universidade do Vale do Paraiba UniVap, Avenida Shishima Hifumi 2911, Sao Jose dos Campos, 12244-000, SP (Brazil) and Laboratory of Biomedical Vibrational Spectroscopy (LEVB), Instituto de Pesquisa e Desenvolvimento (IP and D), Universidade do Vale do Paraiba UniVap, Avenida Shishima Hifumi 2911, Sao Jose dos Campos, 12244-000, SP (Brazil); Marciano, F.R. [Laboratory of Biomedical Nanotechnology (NanoBio), Instituto de Pesquisa e Desenvolvimento (IP and D), Universidade do Vale do Paraiba UniVap, Avenida Shishima Hifumi 2911, Sao Jose dos Campos, 12244-000, SP (Brazil); Laboratory of Biomedical Vibrational Spectroscopy LEVB, Instituto de Pesquisa e Desenvolvimento (IP and D), Universidade do Vale do Paraiba (UniVap), Avenida Shishima Hifumi 2911, Sao Jose dos Campos, 12244-000, SP (Brazil); Ramos, S.C. [Laboratorio Associado de Sensores e Materiais (LAS), Instituto Nacional de Pesquisas Espaciais (INPE), Avenida dos Astronautas 1758, Sao Jose dos Campos, 12.245-970, SP (Brazil); Machado, M.M. [Centro Multidisciplinar para Investigacao Biologica na Area da Ciencia em Animais de Laboratorio (CEMIB), Universidade Estadual de Campinas (UNICAMP), Rua 05 de Junho s/no, Cidade Universitaria ' Zeferino Vaz' , 13083-877, Campinas (Brazil); Corat, E.J. [Laboratorio Associado de Sensores e Materiais (LAS), Instituto Nacional de Pesquisas Espaciais (INPE), Avenida dos Astronautas 1758, Sao Jose dos Campos, 12.245-970, SP (Brazil); Corat, M.A.F. [Centro Multidisciplinar para Investigacao Biologica na Area da Ciencia em Animais de Laboratorio (CEMIB), Universidade Estadual de Campinas (UNICAMP), Rua 05 de Junho s/no, Cidade Universitaria ' Zeferino Vaz' , 13083-877, Campinas (Brazil)

    2011-10-10

    We have analyzed the adhesion of mouse embryonic fibroblasts (MEFs) genetically modified by green fluorescence protein (GFP) gene cultured on vertically-aligned carbon nanotubes (VACNTs) after 6 days. The VACNTs films grown on Ti were obtained by microwave plasma chemical vapor deposition process using Fe catalyst and submitted to an oxygen plasma treatment, for 2 min, at 400 V and 80 mTorr, to convert them to superhydrophilic. Cellular adhesion and morphology were analyzed by scanning electron, fluorescence microscopy, and thermodynamics analysis. Characterizations of superhydrophilic VACNTs films were evaluated by contact angle and X-Ray Photoelectron Spectroscopy. Differences of crowd adhered cells, as well as their spreading on superhydrophilic VACNTs scaffolds, were evaluated using focal adhesion analysis. This study was the first to demonstrate, in real time, that the wettability of VACNTs scaffolds might have enhanced and differential adherence patterns to the MEF-GFP on VACNTs substrates. Highlights: {yields} A simple oxygen plasma treatment was used to obtain superhydrophilic CNT films. {yields} Superhydrophilic CNTs films were successfully produced by incorporation of carboxylic groups. {yields} Cellular adhesion on superhydrophilic VACNT films was analyzed in real time. {yields} Wettability of CNT films directly affects the cellular migration, proliferation and adhesion.

  9. Abscisic acid ameliorates experimental IBD by downregulating cellular adhesion molecule expression and suppressing immune cell infiltration.

    Science.gov (United States)

    Guri, Amir J; Hontecillas, Raquel; Bassaganya-Riera, Josep

    2010-12-01

    Abscisic acid (ABA) has shown effectiveness in ameliorating inflammation in obesity, diabetes and cardiovascular disease models. The objective of this study was to determine whether ABA prevents or ameliorates experimental inflammatory bowel disease (IBD). C57BL/6J mice were fed diets with or without ABA (100mg/kg) for 35 days prior to challenge with 2.5% dextran sodium sulfate (DSS). The severity of clinical disease was assessed daily. Colonic mucosal lesions were evaluated by histopathology, and cellular adhesion molecular and inflammatory markers were assayed by real-time quantitative PCR. Flow cytometry was used to quantify leukocyte populations in the blood, spleen, and mesenteric lymph nodes (MLN). The effect of ABA on cytotoxic T-lymphocyte antigen 4 (CTLA-4) expression in splenocytes was also investigated. ABA significantly ameliorated disease activity, colitis and reduced colonic leukocyte infiltration and inflammation. These improvements were associated with downregulation in vascular cell adhesion marker-1 (VCAM-1), E-selectin, and mucosal addressin adhesion marker-1 (MAdCAM-1) expression. ABA also increased CD4(+) and CD8(+) T-lymphocytes in blood and MLN and regulatory T cells in blood. In vitro, ABA increased CTLA-4 expression through a PPAR γ-dependent mechanism. We conclude that ABA ameliorates gut inflammation by modulating T cell distribution and adhesion molecule expression. Copyright © 2010 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

  10. Combining PALM and SOFI for quantitative imaging of focal adhesions in living cells

    Science.gov (United States)

    Deschout, Hendrik; Lukes, Tomas; Sharipov, Azat; Feletti, Lely; Lasser, Theo; Radenovic, Aleksandra

    2017-02-01

    Focal adhesions are complicated assemblies of hundreds of proteins that allow cells to sense their extracellular matrix and adhere to it. Although most focal adhesion proteins have been identified, their spatial organization in living cells remains challenging to observe. Photo-activated localization microscopy (PALM) is an interesting technique for this purpose, especially since it allows estimation of molecular parameters such as the number of fluorophores. However, focal adhesions are dynamic entities, requiring a temporal resolution below one minute, which is difficult to achieve with PALM. In order to address this problem, we merged PALM with super-resolution optical fluctuation imaging (SOFI) by applying both techniques to the same data. Since SOFI tolerates an overlap of single molecule images, it can improve the temporal resolution compared to PALM. Moreover, an adaptation called balanced SOFI (bSOFI) allows estimation of molecular parameters, such as the fluorophore density. We therefore performed simulations in order to assess PALM and SOFI for quantitative imaging of dynamic structures. We demonstrated the potential of our PALM-SOFI concept as a quantitative imaging framework by investigating moving focal adhesions in living cells.

  11. Does penile tourniquet application alter bacterial adhesion to rat urethral cells: an in vitro study.

    Science.gov (United States)

    Boybeyi-Turer, Ozlem; Kacmaz, Birgul; Arat, Esra; Atasoy, Pınar; Kisa, Ucler; Gunal, Yasemin Dere; Aslan, Mustafa Kemal; Soyer, Tutku

    2018-04-01

    To investigate the effects of penile tourniquet (PT) application on bacterial adhesion to urothelium. Fifty-six rats were allocated into control group (CG), sham group (SG), PT group (PTG). No intervention was applied in CG. A 5mm-length urethral repair was performed in SG and PTG. In PTG, a 10-min duration of PT was applied during the procedure and the tissue oxygenation monitor was used to adjust the same degree of ischemia in all subjects. Samples were examined for wound healing parameters and tissue levels of inflammatory markers, eNOS, e-selectin, and ICAM-1antibodies. The adhesion of Escherichia coli to urothelium was investigated with in vitro adhesion assay. Inflammation was higher and wound healing was worse in SG than CG and in PTG in comparison to CG and SG (pcaused endothelial corruption and prevented cell proliferation in cell culture. The PT application does not improve wound healing and increases bacterial adhesion molecules in penile tissue. The in vitro assays showed that PT causes severe endothelial damage and inhibits endothelial cell proliferation. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Adhesion and endothelialization of endothelial cells on the surface of endovascular stents by the novel rotational culture of cells

    International Nuclear Information System (INIS)

    Tang Chaojun; Wang Guixue; Cao Yi; Wu Xue; Xie Xiang; Xiao Li

    2008-01-01

    Recent researches indicate that the initial event in the implantation of endovascular stents involves mechanical injury to the vessel wall. Confluent endothelialization of vascular grafts in vitro before implantation has been suggested as a way to reduce injury of the blood vessel. The purpose of this study is to establish a useful way to improve the adhesion of endothelial cells and accelerate endothelialization on the surface of endovascular stents by a novel rotational culture device. Numerical simulation was used to predict the shear stress on the surface of stents. The number of cellular adhesion was calculated by cell counting, the cell growth was observed by scanning electron microscope and fluorescence microscope. Numerical simulation results showed that the stents was exposed to shear stress of 2.66 x 10 -3 to 8.88 x 10 -2 Pa. Rotational culture of human umbilical vein endothelial cells could enhance the adhesion of cells and accelerate endothelialization on the surface of stents when the culture conditions for EC adhesion were intermediate rotation speed, higher dynamic incubation times, lower cell densities

  13. Differential expression of the neural cell adhesion molecule NCAM 140 in human pituitary tumors

    OpenAIRE

    Aletsee-Ufrecht, M. C.; Langley, O. K.; Gratzl, O.; Gratzl, Manfred

    1990-01-01

    We have analyzed the expression of the intracellular marker protein neuron specific enolase (NSE), synaptophysin (SYN) and of the cell surface marker NCAM (neural cell adhesion molecule) in both normal human hypophysis and in pituitary adenomas in order to explore their potential use as diagnostic tools. All adenomas (4 prolactinomas, 3 growth hormone (GH) producing adenomas and 4 inactive adenomas) showed SYN and NSE immunoreactivity on tissue sections and this was confirmed by immunoblots. ...

  14. Adhesion-mediated self-renewal abilities of Ph+ blastoma cells

    International Nuclear Information System (INIS)

    Funayama, Keiji; Saito-Kurimoto, Yumi; Ebihara, Yasuhiro; Shimane, Miyuki; Nomura, Hitoshi; Tsuji, Ko-ichiro; Asano, Shigetaka

    2010-01-01

    The Philadelphia chromosome-positive blastoma, maintained by serial subcutaneous transplantation in nude mice, is a highly proliferating biological mass consisting of homogenous CD34 + CD38 - myeloblastoid cells. These cells newly evolved from pluripotent leukemia stem cells of chronic myeloid leukemia in the chronic phase. Therefore, this mass may provide a unique tool for better understanding cellular and molecular mechanisms of self-renewal of leukemia stem cells. In this paper, we demonstrated that intravenously injected blastoma cells can cause Ph+ blastic leukemia with multiple invasive foci in NOD/SCID mice but not in nude mice. In addition, using an in vitro culture system, we clearly showed that blastoma cell adhesion to OP9 stromal cells accelerates blastoma cell proliferation that is associated with up-regulation of BMI1 gene expression; increased levels of β-catenin and the Notch1 intra-cellular domain; and changed the expression pattern of variant CD44 forms, which are constitutively expressed in these blastoma cells. These findings strongly suggest that adhesion of leukemic stem cells to stromal cells via CD44 might be indispensable for their cellular defense against attack by immune cells and for maintenance of their self-renewal ability.

  15. Rac1 Regulates the Proliferation, Adhesion, Migration, and Differentiation of MDPC-23 Cells.

    Science.gov (United States)

    Ren, Jing; Liang, Guobin; Gong, Li; Guo, Bing; Jiang, Hongwei

    2017-04-01

    Stem cells are responsible for replacing damaged pulp tissue; therefore, promoting their survival and inducing their adhesion to dentin are vital. As a member of the Rho family of guanosine triphosphatases, Rac1 is an important regulator of osteoblast functions. However, little is known about its role in regenerative endodontic procedures. The current study examined the role of Rac1 in the proliferation, migration, and odontoblastic differentiation of MDPC-23 cells. MDPC-23 cells were transfected with small interfering RNA to knock down Rac1 expression, and then their proliferation, migration, adhesion, and odontoblastic differentiation were examined in vitro. MDPC-23 cells transfected with si-Rac1 exhibited the increased expression of several key odontogenic protein markers, including Dmp1, Dspp, Runx2, and alkaline phosphatase, as well as decreased proliferation and migration in vitro. The results suggest that Rac1 might regulate nuclear factor kappa B signaling in MDPC-23 cells. Rac1 may have vital roles in the proliferation, migration, adhesion, and odontoblastic differentiation of MDPC-23 cells. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  16. Effect of chondroitin sulfate proteoglycans on neuronal cell adhesion, spreading and neurite growth in culture

    Directory of Open Access Journals (Sweden)

    Jingyu Jin

    2018-01-01

    Full Text Available As one major component of extracellular matrix (ECM in the central nervous system, chondroitin sulfate proteoglycans (CSPGs have long been known as inhibitors enriched in the glial scar that prevent axon regeneration after injury. Although many studies have shown that CSPGs inhibited neurite outgrowth in vitro using different types of neurons, the mechanism by which CSPGs inhibit axonal growth remains poorly understood. Using cerebellar granule neuron (CGN culture, in this study, we evaluated the effects of different concentrations of both immobilized and soluble CSPGs on neuronal growth, including cell adhesion, spreading and neurite growth. Neurite length decreased while CSPGs concentration arised, meanwhile, a decrease in cell density accompanied by an increase in cell aggregates formation was observed. Soluble CSPGs also showed an inhibition on neurite outgrowth, but it required a higher concentration to induce cell aggregates formation than coated CSPGs. We also found that growth cone size was significantly reduced on CSPGs and neuronal cell spreading was restrained by CSPGs, attributing to an inhibition on lamellipodial extension. The effect of CSPGs on neuron adhesion was further evidenced by interference reflection microscopy (IRM which directly demonstrated that both CGNs and cerebral cortical neurons were more loosely adherent to a CSPG substrate. These data demonstrate that CSPGs have an effect on cell adhesion and spreading in addition to neurite outgrowth.

  17. Hydrophilic PCU scaffolds prepared by grafting PEGMA and immobilizing gelatin to enhance cell adhesion and proliferation

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Changcan; Yuan, Wenjie; Khan, Musammir; Li, Qian [School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); Feng, Yakai, E-mail: yakaifeng@tju.edu.cn [School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); Key Laboratory of Systems Bioengineering of Ministry of Education, Tianjin University, Tianjin 300072 (China); Tianjin University-Helmholtz-Zentrum Geesthacht, Joint Laboratory for Biomaterials and Regenerative Medicine, Tianjin 300072 (China); Collaborative Innovation Center of Chemical Science and Chemical Engineering (Tianjin) Tianjin 300072 (China); Yao, Fanglian [School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); Key Laboratory of Systems Bioengineering of Ministry of Education, Tianjin University, Tianjin 300072 (China); Tianjin University-Helmholtz-Zentrum Geesthacht, Joint Laboratory for Biomaterials and Regenerative Medicine, Tianjin 300072 (China); Zhang, Wencheng, E-mail: wenchengzhang@yahoo.com [Department of Physiology and Pathophysiology, Logistics University of Chinese People' s Armed Police Force, Tianjin 300162 (China)

    2015-05-01

    Gelatin contains many functional motifs which can modulate cell specific adhesion, so we modified polycarbonate urethane (PCU) scaffold surface by immobilization of gelatin. PCU-g-gelatin scaffolds were prepared by direct immobilizing gelatins onto the surface of aminated PCU scaffolds. To increase the immobilization amount of gelatin, poly(ethylene glycol) methacrylate (PEGMA) was grafted onto PCU scaffolds by surface initiated atom transfer radical polymerization. Then, following amination and immobilization, PCU-g-PEGMA-g-gelatin scaffolds were obtained. Both modified scaffolds were characterized by chemical and biological methods. After immobilization of gelatin, the microfiber surface became rough, but the original morphology of scaffolds was maintained successfully. PCU-g-PEGMA-g-gelatin scaffolds were more hydrophilic than PCU-g-gelatin scaffolds. Because hydrophilic PEGMA and gelatin were grafted and immobilized onto the surface, the PCU-g-PEGMA-g-gelatin scaffolds showed low platelet adhesion, perfect anti-hemolytic activity and excellent cell growth and proliferation capacity. It could be envisioned that PCU-g-PEGMA-g-gelatin scaffolds might have potential applications in tissue engineering artificial scaffolds. - Graphical abstract: PCU-g-gelatin scaffolds were prepared by direct immobilizing gelatin onto the surface of aminated PCU scaffolds (method a). To increase the immobilization amount of gelatin, PEGMAs were grafted onto the scaffold surface by SI-ATRP. PCU-g-PEGMA-g-gelatin scaffolds were prepared by method b. The gelatin modified scaffolds exhibited high hydrophilicity, low platelet adhesion, perfect anti-hemolytic activity, and excellent cell adhesion and proliferation capacity. They might have potential applications as tissue engineering scaffolds for artificial blood vessels. - Highlights: • Hydrophilic scaffolds were prepared by grafting PEGMA and immobilization of gelatins. • Grafting PEGMA enhanced the immobilization amount of gelatin

  18. Cellular adhesome screen identifies critical modulators of focal adhesion dynamics, cellular traction forces and cell migration behaviour

    Science.gov (United States)

    Fokkelman, Michiel; Balcıoğlu, Hayri E.; Klip, Janna E.; Yan, Kuan; Verbeek, Fons J.; Danen, Erik H. J.; van de Water, Bob

    2016-01-01

    Cancer cells migrate from the primary tumour into surrounding tissue in order to form metastasis. Cell migration is a highly complex process, which requires continuous remodelling and re-organization of the cytoskeleton and cell-matrix adhesions. Here, we aimed to identify genes controlling aspects of tumour cell migration, including the dynamic organization of cell-matrix adhesions and cellular traction forces. In a siRNA screen targeting most cell adhesion-related genes we identified 200+ genes that regulate size and/or dynamics of cell-matrix adhesions in MCF7 breast cancer cells. In a subsequent secondary screen, the 64 most effective genes were evaluated for growth factor-induced cell migration and validated by tertiary RNAi pool deconvolution experiments. Four validated hits showed significantly enlarged adhesions accompanied by reduced cell migration upon siRNA-mediated knockdown. Furthermore, loss of PPP1R12B, HIPK3 or RAC2 caused cells to exert higher traction forces, as determined by traction force microscopy with elastomeric micropillar post arrays, and led to considerably reduced force turnover. Altogether, we identified genes that co-regulate cell-matrix adhesion dynamics and traction force turnover, thereby modulating overall motility behaviour. PMID:27531518

  19. The molecular mechanism of mediation of adsorbed serum proteins to endothelial cells adhesion and growth on biomaterials.

    Science.gov (United States)

    Yang, Dayun; Lü, Xiaoying; Hong, Ying; Xi, Tingfei; Zhang, Deyuan

    2013-07-01

    To explore molecular mechanism of mediation of adsorbed proteins to cell adhesion and growth on biomaterials, this study examined endothelial cell adhesion, morphology and viability on bare and titanium nitride (TiN) coated nickel titanium (NiTi) alloys and chitosan film firstly, and then identified the type and amount of serum proteins adsorbed on the three surfaces by proteomic technology. Subsequently, the mediation role of the identified proteins to cell adhesion and growth was investigated with bioinformatics analyses, and further confirmed by a series of cellular and molecular biological experiments. Results showed that the type and amount of adsorbed serum proteins associated with cell adhesion and growth was obviously higher on the alloys than on the chitosan film, and these proteins mediated endothelial cell adhesion and growth on the alloys via four ways. First, proteins such as adiponectin in the adsorbed protein layer bound with cell surface receptors to generate signal transduction, which activated cell surface integrins through increasing intracellular calcium level. Another way, thrombospondin 1 in the adsorbed protein layer promoted TGF-β signaling pathway activation and enhanced integrins expression. The third, RGD sequence containing proteins such as fibronectin 1, vitronectin and thrombospondin 1 in the adsorbed protein layer bound with activated integrins to activate focal adhesion pathway, increased focal adhesion formation and actin cytoskeleton organization and mediated cell adhesion and spreading. In addition, the activated focal adhesion pathway promoted the expression of cell growth related genes and resulted in cell proliferation. The fourth route, coagulation factor II (F2) and fibronectin 1 in the adsorbed protein layer bound with cell surface F2 receptor and integrin, activated regulation of actin cytoskeleton pathway and regulated actin cytoskeleton organization. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. Cell adhesion-mediated radioresistance (CAM-RR). Extracellular matrix-dependent improvement of cell survival in human tumor and normal cells in vitro

    International Nuclear Information System (INIS)

    Cordes, N.; Meineke, V.

    2003-01-01

    Background: Cell-extracellular matrix (ECM) contact is thought to have great impact on cellular mechanisms resulting in increased cell survival upon exposure to ionizing radiation. Several human tumor cell lines and normal human fibroblastic cell strains of different origin, all of them expressing the wide-spread and important integrin subunit β1, were irradiated, and clonogenic cell survival, β1-integrin cell surface expression, and adhesive functionality were investigated. Material and Methods: Human tumor cell lines A172 (glioblastoma), PATU8902 (pancreas carcinoma), SKMES1 (lung carcinoma), A549 (lung carcinoma), and IPC298 (melanoma) as well as normal human skin (HSF1) and lung fibroblasts (CCD32) and human keratinocytes (HaCaT) were irradiated with 0-8 Gy. Besides colony formation assays, β1-integrin cell surface expression by flow cytometry and adhesive functionality by adhesion assays were analyzed. Results: All cell lines showed improved clonogenic survival after irradiation in the presence of fibronectin as compared to plastic. Irradiated cells exhibited a significant, dose-dependent increase in β1-integrin cell surface expression following irradiation. As a parameter of the adhesive functionality of the β1-integrin, a radiation-dependent elevation of cell adhesion to fibronectin in comparison with adhesion to plastic was demonstrated. Conclusion: The in vitro cellular radiosensitivity is highly influenced by fibronectin according to the phenomenon of cell adhesion-mediated radioresistance. Additionally, our emerging data question the results of former and current in vitro cytotoxicity studies performed in the absence of an ECM. These findings might also be important for the understanding of malignant transformation, anchorage-independent cell growth, optimization of radiotherapeutic regimes and the prevention of normal tissue side effects on the basis of experimental radiobiological data. (orig.)

  1. Adhesive properties of Enterobacter sakazakii to human epithelial and brain microvascular endothelial cells

    Directory of Open Access Journals (Sweden)

    Pospischil Andreas

    2006-06-01

    Full Text Available Abstract Background Enterobacter sakazakii is an opportunistic pathogen that has been associated with sporadic cases and outbreaks causing meningitis, necrotizing enterocolitis and sepsis especially in neonates. However, up to now little is known about the mechanisms of pathogenicity in E. sakazakii. A necessary state in the successful colonization, establishment and ultimately production of disease by microbial pathogens is the ability to adhere to host surfaces such as mucous membranes, gastric and intestinal epithelial or endothelial tissue. This study examined for the first time the adherence ability of 50 E. sakazakii strains to the two epithelial cell lines HEp-2 and Caco-2, as well as the brain microvascular endothelial cell line HBMEC. Furthermore, the effects of bacterial culture conditions on the adherence behaviour were investigated. An attempt was made to characterize the factors involved in adherence. Results Two distinctive adherence patterns, a diffuse adhesion and the formation of localized clusters of bacteria on the cell surface could be distinguished on all three cell lines. In some strains, a mixture of both patterns was observed. Adherence was maximal during late exponential phase, and increased with higher MOI. The adhesion capacity of E. sakazakii to HBMEC cells was affected by the addition of blood to the bacteria growth medium. Mannose, hemagglutination, trypsin digestion experiments and transmission electron microscopy suggested that the adhesion of E. sakazakii to the epithelial and endothelial cells is mainly non-fimbrial based. Conclusion Adherence experiments show heterogeneity within different E. sakazakii strains. In agreement with studies on E. cloacae, we found no relationship between the adhesive capacities in E. sakazakii and the eventual production of specific fimbriae. Further studies will have to be carried out in order to determine the adhesin(s involved in the interaction of E. sakazakii with cells and to

  2. Investigation of in vitro bone cell adhesion and proliferation on Ti using direct current stimulation

    International Nuclear Information System (INIS)

    Bodhak, Subhadip; Bose, Susmita; Kinsel, William C.; Bandyopadhyay, Amit

    2012-01-01

    Our objective was to establish an in vitro cell culture protocol to improve bone cell attachment and proliferation on Ti substrate using direct current stimulation. For this purpose, a custom made electrical stimulator was developed and a varying range of direct currents, from 5 to 25 μA, was used to study the current stimulation effect on bone cells cultured on conducting Ti samples in vitro. Cell–material interaction was studied for a maximum of 5 days by culturing with human fetal osteoblast cells (hFOB). The direct current was applied in every 8 h time interval and the duration of electrical stimulation was kept constant at 15 min for all cases. In vitro results showed that direct current stimulation significantly favored bone cell attachment and proliferation in comparison to nonstimulated Ti surface. Immunochemistry and confocal microscopy results confirmed that the cell adhesion was most pronounced on 25 μA direct current stimulated Ti surfaces as hFOB cells expressed higher vinculin protein with increasing amount of direct current. Furthermore, MTT assay results established that cells grew 30% higher in number under 25 μA electrical stimulation as compared to nonstimulated Ti surface after 5 days of culture period. In this work we have successfully established a simple and cost effective in vitro protocol offering easy and rapid analysis of bone cell–material interaction which can be used in promotion of bone cell attachment and growth on Ti substrate using direct current electrical stimulation in an in vitro model. - Highlights: ► D.C. stimulation was used to enhance in vitro bone cell adhesion and proliferation. ► Cells cultured on Ti were stimulated by using a custom made electrical stimulator. ► Optimization was performed by using a varying range of direct currents ∼ 5 to 25 μA. ► 25 μA stimulation was found most beneficial for promotion of cell adhesion/growth.

  3. Biological adhesion of the flatworm Macrostomum lignano relies on a duo-gland system and is mediated by a cell type-specific intermediate filament protein

    NARCIS (Netherlands)

    Lengerer, Birgit; Pjeta, Robert; Wunderer, Julia; Rodrigues, Marcelo; Arbore, Roberto; Schaerer, Lukas; Berezikov, Eugene; Hess, Michael W.; Pfaller, Kristian; Egger, Bernhard; Obwegeser, Sabrina; Salvenmoser, Willi; Ladurner, Peter

    2014-01-01

    Background: Free-living flatworms, in both marine and freshwater environments, are able to adhere to and release from a substrate several times within a second. This reversible adhesion relies on adhesive organs comprised of three cell types: an adhesive gland cell, a releasing gland cell, and an

  4. Role of Cbl-associated protein/ponsin in receptor tyrosine kinase signaling and cell adhesion

    Directory of Open Access Journals (Sweden)

    Ritva Tikkanen

    2012-10-01

    Full Text Available The Cbl-associated protein/ponsin (CAP is an adaptor protein that contains a so-called Sorbin homology (SoHo domain and three Src homology 3 (SH3 domains which are engaged in diverse protein-protein interactions. CAP has been shown to function in the regulation of the actin cytoskeleton and cell adhesion and to be involved in the differentiation of muscle cells and adipocytes. In addition, it participates in signaling pathways through several receptor tyrosine kinases such as insulin and neurotrophin receptors. In the last couple of years, several studies have shed light on the details of these processes and identified novel interaction partners of CAP. In this review, we summarize these recent findings and provide an overview on the function of CAP especially in cell adhesion and membrane receptor signaling.

  5. Transgene expression, but not gene delivery, is improved by adhesion-assisted lipofection of hematopoietic cells.

    Science.gov (United States)

    Keller, H; Yunxu, C; Marit, G; Pla, M; Reiffers, J; Thèze, J; Froussard, P

    1999-05-01

    In contrast to adherent cells, cells growing in suspension and particularly hematopoietic cells, are notoriously difficult to transfect in vitro using nonviral approaches. In the present study, the effect of cell adhesion on gene transfer efficacy was investigated by allowing hematopoietic cells to bind to an adherent cell monolayer (ACM) before being subjected to cationic liposome-mediated DNA transfer. Human CD34 and T CD4 cell lines were cultivated on an ACM constituted of murine fibroblast NIH3T3 cells and transfected with a plasmid carrying the beta-galactosidase gene. X-gal staining showed that up to 27% of the cells expressed the transgene. In contrast, less than 0.1% of these cells were positively transfected in suspension. This adhesion-assisted lipofection (AAL) procedure was also successfully tested on blood lymphocytes, since it resulted in up to 30% of transfected human primary T lymphocytes. Flow cytometry analysis performed on T lymphocyte subsets revealed that 8 and 9%, respectively, of CD4 and CD8 cells could be transfected with a plasmid carrying the green fluorescent protein gene. Other adherent cells, such as MS5 murine stromal cells or HeLa epithelial cells, were also a compatible matrix for AAL. Moreover, the pCMV beta plasmid was present in similar amounts in the nuclei of TF1 cells transfected in suspension or with the AAL procedure. These data raise the possibility that cell matrix/hematopoietic cell interactions might govern expression of the transgene in hematopoietic cells growing usually in suspension, but not endocytosis of liposome/DNA particles and plasmid migration ot the cell nucleus.

  6. The selective role of ECM components on cell adhesion, morphology, proliferation and communication in vitro

    International Nuclear Information System (INIS)

    Schlie-Wolter, Sabrina; Ngezahayo, Anaclet; Chichkov, Boris N.

    2013-01-01

    Cell binding to the extracellular matrix (ECM) is essential for cell and tissue functions. In this context, each tissue consists of a unique ECM composition, which may be responsible for tissue-specific cell responses. Due to the complexity of ECM-cell interactions—which depend on the interplay of inside-out and outside-in signaling cascades, cell and tissue specificity of ECM-guidance is poorly understood. In this paper, we investigate the role of different ECM components like laminin, fibronectin, and collagen type I with respect to the essential cell behaviour patterns: attachment dynamics such as adhesion kinetic and force, formation of focal adhesion complexes, morphology, proliferation, and intercellular communication. A detailed in vitro comparison of fibroblasts, endothelial cells, osteoblasts, smooth muscle cells, and chondrocytes reveals significant differences in their cell responses to the ECM: cell behaviour follows a cell specific ligand priority ranking, which was independent of the cell type origin. Fibroblasts responded best to fibronectin, chondrocytes best to collagen I, the other cell types best to laminin. This knowledge is essential for optimization of tissue-biomaterial interfaces in all tissue engineering applications and gives insight into tissue-specific cell guidance. -- Highlights: • We analyse the impact of ECM components on cell behaviour in vitro. • We compare five different cell types, using the same culture conditions. • The ECM significantly guides all cell responses. • Cell behaviour follows a cell specific ligand-priority ranking. • This gives insight in tissue formation and is essential for biomedical applications

  7. The selective role of ECM components on cell adhesion, morphology, proliferation and communication in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Schlie-Wolter, Sabrina, E-mail: s.schlie@lzh.de [Laser Zentrum Hannover e.V., Hollerithallee 8, 30419 Hannover (Germany); Ngezahayo, Anaclet, E-mail: ngezahayo@biophysik.uni-hannover.de [Institute of Biophysics, Leibniz University Hannover, Herrenhäuser Str. 2, Hannover 30419 (Germany); Chichkov, Boris N., E-mail: b.chichkov@lzh.de [Laser Zentrum Hannover e.V., Hollerithallee 8, 30419 Hannover (Germany)

    2013-06-10

    Cell binding to the extracellular matrix (ECM) is essential for cell and tissue functions. In this context, each tissue consists of a unique ECM composition, which may be responsible for tissue-specific cell responses. Due to the complexity of ECM-cell interactions—which depend on the interplay of inside-out and outside-in signaling cascades, cell and tissue specificity of ECM-guidance is poorly understood. In this paper, we investigate the role of different ECM components like laminin, fibronectin, and collagen type I with respect to the essential cell behaviour patterns: attachment dynamics such as adhesion kinetic and force, formation of focal adhesion complexes, morphology, proliferation, and intercellular communication. A detailed in vitro comparison of fibroblasts, endothelial cells, osteoblasts, smooth muscle cells, and chondrocytes reveals significant differences in their cell responses to the ECM: cell behaviour follows a cell specific ligand priority ranking, which was independent of the cell type origin. Fibroblasts responded best to fibronectin, chondrocytes best to collagen I, the other cell types best to laminin. This knowledge is essential for optimization of tissue-biomaterial interfaces in all tissue engineering applications and gives insight into tissue-specific cell guidance. -- Highlights: • We analyse the impact of ECM components on cell behaviour in vitro. • We compare five different cell types, using the same culture conditions. • The ECM significantly guides all cell responses. • Cell behaviour follows a cell specific ligand-priority ranking. • This gives insight in tissue formation and is essential for biomedical applications.

  8. Transparent Conductive Adhesives for Tandem Solar Cells Using Polymer-Particle Composites

    Energy Technology Data Exchange (ETDEWEB)

    Klein, Talysa [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Lee, Benjamin G [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Schnabel, Manuel [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Warren, Emily L [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Stradins, Paul [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Tamboli, Adele C [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Van Hest, Marinus F [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2018-02-14

    Transparent conductive adhesives (TCAs) can enable conductivity between two substrates, which is useful for a wide range of electronic devices. Here, we have developed a TCA composed of a polymer-particle blend with ethylene-vinyl acetate as the transparent adhesive and metal-coated flexible poly(methyl methacrylate) microspheres as the conductive particles that can provide conductivity and adhesion regardless of the surface texture. This TCA layer was designed to be nearly transparent, conductive in only the out-of-plane direction, and of practical adhesive strength to hold the substrates together. The series resistance was measured at 0.3 and 0.8 O cm2 for 8 and 0.2% particle coverage, respectively, while remaining over 92% was transparent in both cases. For applications in photovoltaic devices, such as mechanically stacked multijunction III-V/Si cells, a TCA with 1% particle coverage will have less than 0.5% power loss due to the resistance and less than 1% shading loss to the bottom cell.

  9. Adhesive protein interactions with chitosan: consequences for valve endothelial cell growth on tissue-engineering materials.

    Science.gov (United States)

    Cuy, Janet L; Beckstead, Benjamin L; Brown, Chad D; Hoffman, Allan S; Giachelli, Cecilia M

    2003-11-01

    Stable endothelialization of a tissue-engineered heart valve is essential for proper valve function, although adhesive characteristics of the native valve endothelial cell (VEC) have rarely been explored. This research evaluated VEC adhesive qualities and attempted to enhance VEC growth on the biopolymer chitosan, a novel tissue-engineering scaffold material with promising biological and chemical properties. Aortic VEC cultures were isolated and found to preferentially adhere to fibronectin, collagen types IV and I over laminin and osteopontin in a dose-dependent manner. Seeding of VEC onto comparison substrates revealed VEC growth and morphology to be preferential in the order: tissue culture polystyrene > gelatin, poly(DL-lactide-co-glycolide), chitosan > poly(hydroxy alkanoate). Adhesive protein precoating of chitosan did not significantly enhance VEC growth, despite equivalent protein adsorption as to polystyrene. Initial cell adhesion to protein-precoated chitosan, however, was higher than for polystyrene. Composite chitosan/collagen type IV films were investigated as an alternative to simple protein precoatings, and were shown to improve VEC growth and morphology over chitosan alone. These findings suggest potential manipulation of chitosan properties to improve amenability to valve tissue-engineering applications. Copyright 2003 Wiley Periodicals, Inc.

  10. Cell adhesion controlled by adhesion G protein-coupled receptor GPR124/ADGRA2 is mediated by a protein complex comprising intersectins and Elmo-Dock.

    Science.gov (United States)

    Hernández-Vásquez, Magda Nohemí; Adame-García, Sendi Rafael; Hamoud, Noumeira; Chidiac, Rony; Reyes-Cruz, Guadalupe; Gratton, Jean Philippe; Côté, Jean-François; Vázquez-Prado, José

    2017-07-21

    Developmental angiogenesis and the maintenance of the blood-brain barrier involve endothelial cell adhesion, which is linked to cytoskeletal dynamics. GPR124 (also known as TEM5/ADGRA2) is an adhesion G protein-coupled receptor family member that plays a pivotal role in brain angiogenesis and in ensuring a tight blood-brain barrier. However, the signaling properties of GPR124 remain poorly defined. Here, we show that ectopic expression of GPR124 promotes cell adhesion, additive to extracellular matrix-dependent effect, coupled with filopodia and lamellipodia formation and an enrichment of a pool of the G protein-coupled receptor at actin-rich cellular protrusions containing VASP, a filopodial marker. Accordingly, GPR124-expressing cells also displayed increased activation of both Rac and Cdc42 GTPases. Mechanistically, we uncover novel direct interactions between endogenous GPR124 and the Rho guanine nucleotide exchange factors Elmo/Dock and intersectin (ITSN). Small fragments of either Elmo or ITSN1 that bind GPR124 blocked GPR124-induced cell adhesion. In addition, Gβγ interacts with the C-terminal tail of GPR124 and promotes the formation of a GPR124-Elmo complex. Furthermore, GPR124 also promotes the activation of the Elmo-Dock complex, as measured by Elmo phosphorylation on a conserved C-terminal tyrosine residue. Interestingly, Elmo and ITSN1 also interact with each other independently of their GPR124-recognition regions. Moreover, endogenous phospho-Elmo and ITSN1 co-localize with GPR124 at lamellipodia of adhering endothelial cells, where GPR124 expression contributes to polarity acquisition during wound healing. Collectively, our results indicate that GPR124 promotes cell adhesion via Elmo-Dock and ITSN. This constitutes a previously unrecognized complex formed of atypical and conventional Rho guanine nucleotide exchange factors for Rac and Cdc42 that is putatively involved in GPR124-dependent angiogenic responses. © 2017 by The American Society for

  11. Effects of fibulin-5 on attachment, adhesion, and proliferation of primary human endothelial cells

    International Nuclear Information System (INIS)

    Preis, M.; Cohen, T.; Sarnatzki, Y.; Ben Yosef, Y.; Schneiderman, J.; Gluzman, Z.; Koren, B.; Lewis, B.S.; Shaul, Y.; Flugelman, M.Y.

    2006-01-01

    Background: Fibulin-5 is a novel extracellular protein that is thought to act as a bridging peptide between elastin fibers and cell surface integrins in blood vessel wall. Fibulin-5 binding to endothelial cell (EC) surface integrins may effect cell proliferation and cell attachment to extracellular matrix (ECM) or to artificial surfaces. In this paper, we describe the effects of fibulin-5 on attachment, adhesion, and proliferation of primary human EC. After demonstrating that fibulin-5 over-expression inhibited EC proliferation, we tested the hypothesis that co-expression of fibulin-5 and VEGF 165 will lead to unique EC phenotype that will exhibit increased adherence properties and retain its proliferation capacity. Methods and results: Fibulin-5 and VEGF 165 gene transfer to primary human saphenous vein endothelial cells was accomplished using retroviral vectors encoding the two genes. Transgene expression was verified using immunohistochemistry, Western blotting, and ELISA. Fibulin 5 over-expression tended to improve immediate EC attachment (30 min after seeding) and improved significantly adhesion (>40%) under shear stress tested 24 h after EC seeding. The effects of fibulin-5 and VEGF 165 on EC proliferation in the presence or absence of basic FGF were also tested. EC expressing fibulin-5 had reduced proliferation while VEGF 165 co-expression ameliorated this effect. Conclusion: Fibulin-5 improved EC attachment to artificial surfaces. Dual transfer of fibulin-5 and VEGF 165 resulted in EC phenotype with increased adhesion and improved proliferation. This unique EC phenotype can be useful for tissue engineering on endovascular prostheses

  12. Non-Catalytic Functions of Pyk2 and Fyn Regulate Late Stage Adhesion in Human T Cells

    Science.gov (United States)

    Houtman, Jon C. D.

    2012-01-01

    T cell activation drives the protective immune response against pathogens, but is also critical for the development of pathological diseases in humans. Cytoskeletal changes are required for downstream functions in T cells, including proliferation, cytokine production, migration, spreading, and adhesion. Therefore, investigating the molecular mechanism of cytoskeletal changes is crucial for understanding the induction of T cell-driven immune responses and for developing therapies to treat immune disorders related to aberrant T cell activation. In this study, we used a plate-bound adhesion assay that incorporated near-infrared imaging technology to address how TCR signaling drives human T cell adhesion. Interestingly, we observed that T cells have weak adhesion early after TCR activation and that binding to the plate was significantly enhanced 30–60 minutes after receptor activation. This late stage of adhesion was mediated by actin polymerization but was surprisingly not dependent upon Src family kinase activity. By contrast, the non-catalytic functions of the kinases Fyn and Pyk2 were required for late stage human T cell adhesion. These data reveal a novel TCR-induced signaling pathway that controls cellular adhesion independent of the canonical TCR signaling cascade driven by tyrosine kinase activity. PMID:23300847

  13. Cell adhesion on NiTi thin film sputter-deposited meshes

    International Nuclear Information System (INIS)

    Loger, K.; Engel, A.; Haupt, J.; Li, Q.; Lima de Miranda, R.; Quandt, E.; Lutter, G.; Selhuber-Unkel, C.

    2016-01-01

    Scaffolds for tissue engineering enable the possibility to fabricate and form biomedical implants in vitro, which fulfill special functionality in vivo. In this study, free-standing Nickel–Titanium (NiTi) thin film meshes were produced by means of magnetron sputter deposition. Meshes contained precisely defined rhombic holes in the size of 440 to 1309 μm 2 and a strut width ranging from 5.3 to 9.2 μm. The effective mechanical properties of the microstructured superelastic NiTi thin film were examined by tensile testing. These results will be adapted for the design of the holes in the film. The influence of hole and strut dimensions on the adhesion of sheep autologous cells (CD133 +) was studied after 24 h and after seven days of incubation. Optical analysis using fluorescence microscopy and scanning electron microscopy showed that cell adhesion depends on the structural parameters of the mesh. After 7 days in cell culture a large part of the mesh was covered with aligned fibrous material. Cell adhesion is particularly facilitated on meshes with small rhombic holes of 440 μm 2 and a strut width of 5.3 μm. Our results demonstrate that free-standing NiTi thin film meshes have a promising potential for applications in cardiovascular tissue engineering, particularly for the fabrication of heart valves. - Highlights: • Freestanding NiTi thin film scaffolds were fabricated with magnetron sputtering process. • Effective mechanical properties of NiTi scaffolds can be adapted by the mesh structure parameters. • Cell adhesion on the NiTi thin film scaffold is controlled by the structure parameters of the mesh. • Cells strongly adhere after seven days and form a confluent layer on the mesh.

  14. Cell adhesion on NiTi thin film sputter-deposited meshes

    Energy Technology Data Exchange (ETDEWEB)

    Loger, K. [Inorganic Functional Materials, Institute for Materials Science, Faculty of Engineering, University of Kiel (Germany); Engel, A.; Haupt, J. [Department of Cardiovascular Surgery, University Hospital of Schleswig-Holstein, Kiel (Germany); Li, Q. [Biocompatible Nanomaterials, Institute for Materials Science, Faculty of Engineering, University of Kiel (Germany); Lima de Miranda, R. [Inorganic Functional Materials, Institute for Materials Science, Faculty of Engineering, University of Kiel (Germany); ACQUANDAS GmbH, Kiel (Germany); Quandt, E. [Inorganic Functional Materials, Institute for Materials Science, Faculty of Engineering, University of Kiel (Germany); Lutter, G. [Department of Cardiovascular Surgery, University Hospital of Schleswig-Holstein, Kiel (Germany); Selhuber-Unkel, C. [Biocompatible Nanomaterials, Institute for Materials Science, Faculty of Engineering, University of Kiel (Germany)

    2016-02-01

    Scaffolds for tissue engineering enable the possibility to fabricate and form biomedical implants in vitro, which fulfill special functionality in vivo. In this study, free-standing Nickel–Titanium (NiTi) thin film meshes were produced by means of magnetron sputter deposition. Meshes contained precisely defined rhombic holes in the size of 440 to 1309 μm{sup 2} and a strut width ranging from 5.3 to 9.2 μm. The effective mechanical properties of the microstructured superelastic NiTi thin film were examined by tensile testing. These results will be adapted for the design of the holes in the film. The influence of hole and strut dimensions on the adhesion of sheep autologous cells (CD133 +) was studied after 24 h and after seven days of incubation. Optical analysis using fluorescence microscopy and scanning electron microscopy showed that cell adhesion depends on the structural parameters of the mesh. After 7 days in cell culture a large part of the mesh was covered with aligned fibrous material. Cell adhesion is particularly facilitated on meshes with small rhombic holes of 440 μm{sup 2} and a strut width of 5.3 μm. Our results demonstrate that free-standing NiTi thin film meshes have a promising potential for applications in cardiovascular tissue engineering, particularly for the fabrication of heart valves. - Highlights: • Freestanding NiTi thin film scaffolds were fabricated with magnetron sputtering process. • Effective mechanical properties of NiTi scaffolds can be adapted by the mesh structure parameters. • Cell adhesion on the NiTi thin film scaffold is controlled by the structure parameters of the mesh. • Cells strongly adhere after seven days and form a confluent layer on the mesh.

  15. Vascular Cell Adhesion Molecule 1, Intercellular Adhesion Molecule 1, and Cluster of Differentiation 146 Levels in Patients with Type 2 Diabetes with Complications.

    Science.gov (United States)

    Hocaoglu-Emre, F Sinem; Saribal, Devrim; Yenmis, Guven; Guvenen, Guvenc

    2017-03-01

    Type 2 diabetes mellitus (T2DM) is a multisystemic, chronic disease accompanied by microvascular complications involving various complicated mechanisms. Intercellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1), and cluster of differentiation-146 (CD146) are mainly expressed by endothelial cells, and facilitate the adhesion and transmigration of immune cells, leading to inflammation. In the present study, we evaluated the levels of soluble adhesion molecules in patients with microvascular complications of T2DM. Serum and whole blood samples were collected from 58 T2DM patients with microvascular complications and 20 age-matched healthy subjects. Levels of soluble ICAM-1 (sICAM-1) and soluble VCAM-1 (sVCAM-1) were assessed using enzyme-linked immunosorbent assay, while flow cytometry was used to determine CD146 levels. Serum sICAM-1 levels were lower in T2DM patients with microvascular complications than in healthy controls (Pmolecule levels were not correlated with the complication type. In the study group, most of the patients were on insulin therapy (76%), and 95% of them were receiving angiotensin-converting enzyme (ACE)-inhibitor agents. Insulin and ACE-inhibitors have been shown to decrease soluble adhesion molecule levels via various mechanisms, so we suggest that the decreased or unchanged levels of soluble forms of cellular adhesion molecules in our study group may have resulted from insulin and ACE-inhibitor therapy, as well as tissue-localized inflammation in patients with T2DM. Copyright © 2017 Korean Endocrine Society

  16. [Effect of LPXN Overexpression on the Proliferation, Adhesion and Invasion of THP-1 Cells and Its Mechamisms].

    Science.gov (United States)

    Dai, Hai-Ping; Zhu, Guo-Hua; Wu, Li-Li; Wang, Qian; Yao, Hong; Wang, Qin-Rong; Wen, Li-Jun; Qiu, Hui-Ying; Shen, Qun; Chen, Su-Ning; Wu, De-Pei

    2017-06-01

    To explore the effect of LPXN overexpression on the proliferation, adhesion and invasion of THP-1 cells and its possible mechanism. A THP-1 cell line with stable overexpression of LPXN was constucted by using a lentivirus method, CCK-8 was used to detect the proliferation of cells, adhesion test was used to evaluate adhesion ablity of cells to Fn. Transwell assay was used to detect the change of invasion capability. Western blot was used to detect expression of LPXN, ERK, pERK and integrin α4, α5, β1, the Gelatin zymography was applied to detect activity of MMP2/MMP9 secreted by the THP-1 cells. Successful establishment of THP-1 cells with LPXN overexpression (THP-1 LPXN) was confirmed with Western blot. THP-1 LPXN cells were shown to proliferate faster than the control THP-1 vector cells. Adhesion to Fn and expression of ERK, integrin α4, α5 and β1 in the THP-1 LPXN cells were higher than that in the control cells. Invasion across matrigel and enhanced activity of MMP2 could be detected both in the THP-1 LPXN cells as compared with the control cells. Ectopically ovexpression of LPXN may promote proliferation of THP-1 cells through up-regulation of ERK; promote adhesion of THP-1 cells through up-regulating the integrin α4/β1 as well as integrin α5/β1 complex; promote invasion of THP-1 cells through activating MMP2.

  17. Characterisation of cellular adhesion reinforcement by multiple bond force spectroscopy in alveolar epithelial cells.

    Science.gov (United States)

    Nguyen, Ngoc-Minh; Angely, Christelle; Andre Dias, Sofia; Planus, Emmanuelle; Filoche, Marcel; Pelle, Gabriel; Louis, Bruno; Isabey, Daniel

    2017-07-01

    Integrin-mediated adhesion is a key process by which cells physically connect with their environment, and express sensitivity and adaptation through mechanotransduction. A critical step of cell adhesion is the formation of the first bonds which individually generate weak contacts (∼tens pN) but can sustain thousand times higher forces (∼tens nN) when associated. We propose an experimental validation by multiple bond force spectroscopy (MFS) of a stochastic model predicting adhesion reinforcement permitted by non-cooperative, multiple bonds on which force is homogeneously distributed (called parallel bond configuration). To do so, spherical probes (diameter: 6.6 μm), specifically coated by RGD-peptide to bind integrins, are used to statically indent and homogenously stretch the multiple bonds created for short contact times (2 s) between the bead and the surface of epithelial cells (A549). Using different separation speeds (v = 2, 5, 10 μm/s) and measuring cellular Young's modulus as well as the local stiffness preceding local rupture events, we obtain cell-by-cell the effective loading rates both at the global cell level and at the local level of individual constitutive bonds. Local rupture forces are in the range: f*=60-115 pN , whereas global rupture (detachment) forces reach F*=0.8-1.7 nN . Global and local rupture forces both exhibit linear dependencies with the effective loading rate, the slopes of these two linear relationships providing an estimate of the number of independent integrin bonds constituting the tested multiple bond structure (∼12). The MFS method enables to validate the reinforcement of integrin-mediated adhesion induced by the multiple bond configuration in which force is homogeneously distributed amongst parallel bonds. Local rupture events observed in the course of a spectroscopy manoeuver (MFS) lead to rupture force values considered in the literature as single-integrin bonds. Adhesion reinforcement permitted by the parallel

  18. FGFR4 Downregulation of Cell Adhesion in Prostate Cancer

    Science.gov (United States)

    2008-09-01

    in Figure 1, all constructs were stably incorporated into 293-RXR cells and were inducible upon treatment with Ponasterone A. Though we had created...through the transmembrane domain, similar to the FGFR3 Gly380Arg mutation responsible for human dwarfism , or achondroplasia. In this model, the FGFR4

  19. Mechanisms of eosinophil adhesion to endothelial cells under flow conditions

    NARCIS (Netherlands)

    Ulfman, L.H.

    2002-01-01

    Eosinophils play an important role in allergic inflammatory diseases such as allergic asthma. Infiltrates of these cells are present in the interstitium and the lumen of the bronchi of asthmatic patients. Eosinophils must pass the endothelium to enter this site of inflammation. A widely accepted

  20. IMPLICATIONS OF MICROBIAL ADHESION TO HYDROCARBONS FOR EVALUATING CELL-SURFACE HYDROPHOBICITY .1. ZETA-POTENTIALS OF HYDROCARBON DROPLETS

    NARCIS (Netherlands)

    BUSSCHER, HJ; VANDEBELTGRITTER, B; VANDERMEI, HC

    1995-01-01

    Microbial adhesion to hydrocarbons (MATH) is generally considered to be a measure of the organisms cell surface hydrophobicity. As microbial adhesion is a complicated interplay of long-range van der Waals and electrostatic forces and various short-range interactions, the above statement only holds

  1. Decreased expression of cell adhesion genes in cancer stem-like cells isolated from primary oral squamous cell carcinomas.

    Science.gov (United States)

    Mishra, Amrendra; Sriram, Harshini; Chandarana, Pinal; Tanavde, Vivek; Kumar, Rekha V; Gopinath, Ashok; Govindarajan, Raman; Ramaswamy, S; Sadasivam, Subhashini

    2018-05-01

    The goal of this study was to isolate cancer stem-like cells marked by high expression of CD44, a putative cancer stem cell marker, from primary oral squamous cell carcinomas and identify distinctive gene expression patterns in these cells. From 1 October 2013 to 4 September 2015, 76 stage III-IV primary oral squamous cell carcinoma of the gingivobuccal sulcus were resected. In all, 13 tumours were analysed by immunohistochemistry to visualise CD44-expressing cells. Expression of CD44 within The Cancer Genome Atlas-Head and Neck Squamous Cell Carcinoma RNA-sequencing data was also assessed. Seventy resected tumours were dissociated into single cells and stained with antibodies to CD44 as well as CD45 and CD31 (together referred as Lineage/Lin). From 45 of these, CD44 + Lin - and CD44 - Lin - subpopulations were successfully isolated using fluorescence-activated cell sorting, and good-quality RNA was obtained from 14 such sorted pairs. Libraries from five pairs were sequenced and the results analysed using bioinformatics tools. Reverse transcription quantitative polymerase chain reaction was performed to experimentally validate the differential expression of selected candidate genes identified from the transcriptome sequencing in the same 5 and an additional 9 tumours. CD44 was expressed on the surface of poorly differentiated tumour cells, and within the The Cancer Genome Atlas-Head and Neck Squamous Cell Carcinoma samples, its messenger RNA levels were higher in tumours compared to normal. Transcriptomics revealed that 102 genes were upregulated and 85 genes were downregulated in CD44 + Lin - compared to CD44 - Lin - cells in at least 3 of the 5 tumours sequenced. The upregulated genes included those involved in immune regulation, while the downregulated genes were enriched for genes involved in cell adhesion. Decreased expression of PCDH18, MGP, SPARCL1 and KRTDAP was confirmed by reverse transcription quantitative polymerase chain reaction. Lower expression of

  2. PRL-3 engages the focal adhesion pathway in triple-negative breast cancer cells to alter actin structure and substrate adhesion properties critical for cell migration and invasion.

    Science.gov (United States)

    Gari, Hamid H; DeGala, Gregory D; Ray, Rahul; Lucia, M Scott; Lambert, James R

    2016-10-01

    Triple-negative breast cancers (TNBCs) are among the most aggressive cancers characterized by a high propensity to invade, metastasize and relapse. We previously reported that the TNBC-specific inhibitor, AMPI-109, significantly impairs the ability of TNBC cells to migrate and invade by reducing levels of the metastasis-promoting phosphatase, PRL-3. Here, we examined the mechanisms by which AMPI-109 and loss of PRL-3 impede cell migration and invasion. AMPI-109 treatment or knock down of PRL-3 expression were associated with deactivation of Src and ERK signaling and concomitant downregulation of RhoA and Rac1/2/3 GTPase protein levels. These cellular changes led to rearranged filamentous actin networks necessary for cell migration and invasion. Conversely, overexpression of PRL-3 promoted TNBC cell invasion by upregulating matrix metalloproteinase 10, which resulted in increased TNBC cell adherence to, and degradation of, the major basement membrane component laminin. Our data demonstrate that PRL-3 engages the focal adhesion pathway in TNBC cells as a key mechanism for promoting TNBC cell migration and invasion. Collectively, these data suggest that blocking PRL-3 activity may be an effective method for reducing the metastatic potential of TNBC cells. Copyright © 2016 The Author(s). Published by Elsevier Ireland Ltd.. All rights reserved.

  3. Biological role of site-specific O-glycosylation in cell adhesion activity and phosphorylation of osteopontin.

    Science.gov (United States)

    Oyama, Midori; Kariya, Yoshinobu; Kariya, Yukiko; Matsumoto, Kana; Kanno, Mayumi; Yamaguchi, Yoshiki; Hashimoto, Yasuhiro

    2018-05-09

    Osteopontin (OPN) is an extracellular glycosylated phosphoprotein that promotes cell adhesion by interacting with several integrin receptors. We previously reported that an OPN mutant lacking five O-glycosylation sites (Thr 134 /Thr 138 /Thr 143 /Thr 147 /Thr 152 ) in the threonine/proline-rich region increased cell adhesion activity and phosphorylation compared with the wild type. However, the role of O-glycosylation in cell adhesion activity and phosphorylation of OPN remains to be clarified. Here, we show that site-specific O-glycosylation in the threonine/proline-rich region of OPN affects its cell adhesion activity and phosphorylation independently and/or synergistically. Using site-directed mutagenesis, we found that OPN mutants with substitution sets of Thr 134 /Thr 138 or Thr 143 /Thr 147 /Thr 152 had decreased and increased cell adhesion activity, respectively. In contrast, the introduction of a single mutation into the O-glycosylation sites had no effect on OPN cell adhesion activity. An adhesion assay using function-blocking antibodies against αvβ3 and β1 integrins, as well as αvβ3 integrin-overexpressing A549 cells, revealed that site-specific O-glycosylation affected the association of OPN with the two integrins. Phosphorylation analyses using phos-tag and LC-MS/MS indicated that phosphorylation levels and sites were influenced by the O-glycosylation status, although the number of O-glycosylation sites was not correlated with the phosphorylation level in OPN. Furthermore, a correlation analysis between phosphorylation level and cell adhesion activity in OPN mutants with the site-specific O-glycosylation showed that they were not always correlated. These results provide conclusive evidence of a novel regulatory mechanism of cell adhesion activity and phosphorylation of OPN by site-specific O-glycosylation. © 2018 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

  4. Rationally engineered nanoparticles target multiple myeloma cells, overcome cell-adhesion-mediated drug resistance, and show enhanced efficacy in vivo

    International Nuclear Information System (INIS)

    Kiziltepe, T; Ashley, J D; Stefanick, J F; Qi, Y M; Alves, N J; Handlogten, M W; Suckow, M A; Navari, R M; Bilgicer, B

    2012-01-01

    In the continuing search for effective cancer treatments, we report the rational engineering of a multifunctional nanoparticle that combines traditional chemotherapy with cell targeting and anti-adhesion functionalities. Very late antigen-4 (VLA-4) mediated adhesion of multiple myeloma (MM) cells to bone marrow stroma confers MM cells with cell-adhesion-mediated drug resistance (CAM-DR). In our design, we used micellar nanoparticles as dynamic self-assembling scaffolds to present VLA-4-antagonist peptides and doxorubicin (Dox) conjugates, simultaneously, to selectively target MM cells and to overcome CAM-DR. Dox was conjugated to the nanoparticles through an acid-sensitive hydrazone bond. VLA-4-antagonist peptides were conjugated via a multifaceted synthetic procedure for generating precisely controlled number of targeting functionalities. The nanoparticles were efficiently internalized by MM cells and induced cytotoxicity. Mechanistic studies revealed that nanoparticles induced DNA double-strand breaks and apoptosis in MM cells. Importantly, multifunctional nanoparticles overcame CAM-DR, and were more efficacious than Dox when MM cells were cultured on fibronectin-coated plates. Finally, in a MM xenograft model, nanoparticles preferentially homed to MM tumors with ∼10 fold more drug accumulation and demonstrated dramatic tumor growth inhibition with a reduced overall systemic toxicity. Altogether, we demonstrate the disease driven engineering of a nanoparticle-based drug delivery system, enabling the model of an integrative approach in the treatment of MM

  5. Influence of surfaces modified with biomimetic extracellular matrices on adhesion and proliferation of mesenchymal stem cells and osteosarcoma cells.

    Science.gov (United States)

    Cai, Rong; Kawazoe, Naoki; Chen, Guoping

    2015-02-01

    Preparation of surfaces modified with biomimetic extracellular matrices (ECMs) is important for investigation of the interaction between ECMs and cells. In the present study, surfaces modified with ECMs from normal somatic cells, stem cells and tumor cells were prepared by cell culture method. The ECMs derived from bone marrow-derived mesenchymal stem cells (MSCs), dermal fibroblasts (FBs), osteoblasts (OBs) and MG63 osteosarcoma cells were deposited on the surfaces of cell-culture polystyrene plates (TCPS). The ECMs from different cell types had different compositions. The effects of the ECM-deposited surfaces on the adhesion, spreading and proliferation of MSCs and MG63 human osteosarcoma cells were dependent on the type of both ECMs and cells. The surfaces deposited with ECMs from MSCs, FBs and OBs promoted cell adhesion more strongly than surfaces deposited with ECMs from MG63 cells and TCPS. Compared to TCPS, the ECM-deposited surfaces promoted proliferation of MSCs while they inhibited the proliferation of MG63 cells. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Surface strategies for control of neuronal cell adhesion: A review

    Science.gov (United States)

    Roach, P.; Parker, T.; Gadegaard, N.; Alexander, M. R.

    2010-06-01

    Material engineering methods have been used for many years to develop biomedical devices for use within the body to augment, repair or replace damaged tissues ranging from contact lenses to heart valves. Here we review the findings gathered from the wide and varied surface analytical approaches applied to study the interaction between biology and man-made materials. The key material characteristics identified to be important for biological recognition are surface chemistry, topography and compliance. Model surfaces with controlled chemistry and topography have provided insight into biological response to various types of topographical features over a wide range of length scales from nano to micrometres, along with 3D matrices that have been used as scaffolds to support cells for tissue formation. The cellular response to surfaces with localised areas of patterned chemistry and to those presenting gradually changing chemistry are discussed. Where previous reviews have been structured around specific classes of surface modification, e.g. self-assembly, or have broadly examined the response of various cells to numerous surfaces, we aim in this article to focus in particular on the tissues involved in the nervous system whilst providing a broad overview of key issues from the field of cell and protein surface interactions with surfaces. The goal of repair and treatment of diseases related to the central and peripheral nervous systems rely on understanding the local interfacial environment and controlling responses at the cellular level. The role of the protein layer deposited from serum containing media onto man-made surfaces is discussed. We highlight the particular problems associated with the repair of the nervous system, and review how neuronal attachment and axon guidance can be accomplished using various surface cues when cultured with single and multiple cell types. We include a brief glossary of techniques discussed in the body of this article aimed at the

  7. Dietary Lipids, Cell Adhesion and Breast Cancer Metastasis

    Science.gov (United States)

    2003-10-01

    Mustela vison ): a light and electron microscopic study. APMIS 106. 785-799.caspase activity and apoptosis in neuronal cells (Francois et suy PI...N.Y. Acad. Sci. 919, 97-105. tic lesions in the mink ( Mustela vison ): A light and electron microscopic Krause, T., and Turner, G. A. (1999). Are...lipid composition is the most critical factor determining HUVEC with a plasmid regulated by a strong respiratory the efficiency of liposome-mediated

  8. Cell adhesion and proliferation on polyethylene grafted with Au nanoparticles

    Czech Academy of Sciences Publication Activity Database

    Kasálková-Slepičková, N.; Slepička, P.; Kolská, Z.; Sajdl, P.; Bačáková, Lucie; Rimpelová, S.; Švorčík, V.

    2012-01-01

    Roč. 272, FEB 1 (2012), s. 391-395 ISSN 0168-583X. [International Conference on Ion Beam Modification of Materials /17./. Montreal, 22.08.2010-27.08.2010] R&D Projects: GA ČR(CZ) GAP108/10/1106; GA AV ČR(CZ) KAN400480701 Institutional research plan: CEZ:AV0Z50110509 Keywords : polyenthyne * gold nanoparticles * grafting * cell proliferation Subject RIV: EI - Biotechnology ; Bionics Impact factor: 1.266, year: 2012

  9. Augmented vascular smooth muscle cell stiffness and adhesion when hypertension is superimposed on aging.

    Science.gov (United States)

    Sehgel, Nancy L; Sun, Zhe; Hong, Zhongkui; Hunter, William C; Hill, Michael A; Vatner, Dorothy E; Vatner, Stephen F; Meininger, Gerald A

    2015-02-01

    Hypertension and aging are both recognized to increase aortic stiffness, but their interactions are not completely understood. Most previous studies have attributed increased aortic stiffness to changes in extracellular matrix proteins that alter the mechanical properties of the vascular wall. Alternatively, we hypothesized that a significant component of increased vascular stiffness in hypertension is due to changes in the mechanical and adhesive properties of vascular smooth muscle cells, and that aging would augment the contribution from vascular smooth muscle cells when compared with the extracellular matrix. Accordingly, we studied aortic stiffness in young (16-week-old) and old (64-week-old) spontaneously hypertensive rats and Wistar-Kyoto wild-type controls. Systolic and pulse pressures were significantly increased in young spontaneously hypertensive rats when compared with young Wistar-Kyoto rats, and these continued to rise in old spontaneously hypertensive rats when compared with age-matched controls. Excised aortic ring segments exhibited significantly greater elastic moduli in both young and old spontaneously hypertensive rats versus Wistar-Kyoto rats. were isolated from the thoracic aorta, and stiffness and adhesion to fibronectin were measured by atomic force microscopy. Hypertension increased both vascular smooth muscle cell stiffness and vascular smooth muscle cell adhesion, and these increases were both augmented with aging. By contrast, hypertension did not affect histological measures of aortic collagen and elastin, which were predominantly changed by aging. These findings support the concept that stiffness and adhesive properties of vascular smooth muscle cells are novel mechanisms contributing to the increased aortic stiffness occurring with hypertension superimposed on aging. © 2014 American Heart Association, Inc.

  10. Biodegradable electrospun nanofibers coated with platelet-rich plasma for cell adhesion and proliferation

    International Nuclear Information System (INIS)

    Diaz-Gomez, Luis; Alvarez-Lorenzo, Carmen; Concheiro, Angel; Silva, Maite; Dominguez, Fernando; Sheikh, Faheem A.; Cantu, Travis; Desai, Raj; Garcia, Vanessa L.; Macossay, Javier

    2014-01-01

    Biodegradable electrospun poly(ε-caprolactone) (PCL) scaffolds were coated with platelet-rich plasma (PRP) to improve cell adhesion and proliferation. PRP was obtained from human buffy coat, and tested on human adipose-derived mesenchymal stem cells (MSCs) to confirm cell proliferation and cytocompatibility. Then, PRP was adsorbed on the PCL scaffolds via lyophilization, which resulted in a uniform sponge-like coating of 2.85 (S.D. 0.14) mg/mg. The scaffolds were evaluated regarding mechanical properties (Young's modulus, tensile stress and tensile strain), sustained release of total protein and growth factors (PDGF-BB, TGF-β1 and VEGF), and hemocompatibility. MSC seeded on the PRP–PCL nanofibers showed an increased adhesion and proliferation compared to pristine PCL fibers. Moreover, the adsorbed PRP enabled angiogenesis features observed as neovascularization in a chicken chorioallantoic membrane (CAM) model. Overall, these results suggest that PRP–PCL scaffolds hold promise for tissue regeneration applications. - Highlights: • Platelet-rich plasma (PRP) can be adsorbed on electrospun fibers via lyophilization. • PRP coating enhanced mesenchymal stem cell adhesion and proliferation on scaffolds. • PRP-coated scaffolds showed sustained release of growth factors. • Adsorbed PRP provided angiogenic features. • PRP-poly(ε-caprolactone) scaffolds hold promise for tissue regeneration applications

  11. Biodegradable electrospun nanofibers coated with platelet-rich plasma for cell adhesion and proliferation

    Energy Technology Data Exchange (ETDEWEB)

    Diaz-Gomez, Luis [Departamento de Farmacia y Tecnología Farmacéutica, Facultad de Farmacia, Universidad de Santiago de Compostela, 15872 Santiago de Compostela (Spain); Instituto de Ortopedia y Banco de Tejidos Musculoesqueléticos, Universidad de Santiago de Compostela, 15872 Santiago de Compostela (Spain); Alvarez-Lorenzo, Carmen, E-mail: carmen.alvarez.lorenzo@usc.es [Departamento de Farmacia y Tecnología Farmacéutica, Facultad de Farmacia, Universidad de Santiago de Compostela, 15872 Santiago de Compostela (Spain); Concheiro, Angel [Departamento de Farmacia y Tecnología Farmacéutica, Facultad de Farmacia, Universidad de Santiago de Compostela, 15872 Santiago de Compostela (Spain); Silva, Maite [Instituto de Ortopedia y Banco de Tejidos Musculoesqueléticos, Universidad de Santiago de Compostela, 15872 Santiago de Compostela (Spain); Dominguez, Fernando [Fundación Publica Galega de Medicina Xenómica, Santiago de Compostela (Spain); Sheikh, Faheem A.; Cantu, Travis; Desai, Raj; Garcia, Vanessa L. [Department of Chemistry, University of Texas Pan American, Edinburg, TX 78541 (United States); Macossay, Javier, E-mail: jmacossay@utpa.edu [Department of Chemistry, University of Texas Pan American, Edinburg, TX 78541 (United States)

    2014-07-01

    Biodegradable electrospun poly(ε-caprolactone) (PCL) scaffolds were coated with platelet-rich plasma (PRP) to improve cell adhesion and proliferation. PRP was obtained from human buffy coat, and tested on human adipose-derived mesenchymal stem cells (MSCs) to confirm cell proliferation and cytocompatibility. Then, PRP was adsorbed on the PCL scaffolds via lyophilization, which resulted in a uniform sponge-like coating of 2.85 (S.D. 0.14) mg/mg. The scaffolds were evaluated regarding mechanical properties (Young's modulus, tensile stress and tensile strain), sustained release of total protein and growth factors (PDGF-BB, TGF-β1 and VEGF), and hemocompatibility. MSC seeded on the PRP–PCL nanofibers showed an increased adhesion and proliferation compared to pristine PCL fibers. Moreover, the adsorbed PRP enabled angiogenesis features observed as neovascularization in a chicken chorioallantoic membrane (CAM) model. Overall, these results suggest that PRP–PCL scaffolds hold promise for tissue regeneration applications. - Highlights: • Platelet-rich plasma (PRP) can be adsorbed on electrospun fibers via lyophilization. • PRP coating enhanced mesenchymal stem cell adhesion and proliferation on scaffolds. • PRP-coated scaffolds showed sustained release of growth factors. • Adsorbed PRP provided angiogenic features. • PRP-poly(ε-caprolactone) scaffolds hold promise for tissue regeneration applications.

  12. Cell Adhesion Modification of Streptococcus viridians in the Presence of Xylitol

    Science.gov (United States)

    Esmacher, Jason; Vidakovich, Blair; Giangrande, Michael; Hoffmann, Peter

    2012-10-01

    There is scientific documentation that those who chew gum sweetened by the sugar alcohol xylitol report a dramatically lower incident of both dental caries and otitis media compared to those who chew conventional gum sweetened by sucrose. An explanation contends that xylitol interferes with the ability of Streptococcus viridian (SV) to form biofilms which is a necessary precursor to the bacteria's ability to damage human tissues. We have used atomic force microscopy to study the cell wall/fimbria properties at the nanonewton level in both the presence and absence of xylitol. The first set of measurements used varying concentrations of xylitol incorporated within the incubation medium. The second used non-xylitol grown bacteria, the xylitol was added externally at various concentrations. Our study suggests that growing SV with xylitol reduces their ability to adhere together. Additionally, externally added xylitol showed grouping of cell adhesion to a relatively narrow nanonewton spread that is concentration dependent. Measurement of the adhesion properties of the bacterial cell wall have found that there is a dramatic increase in the cell wall's firmness which simultaneously accompanied a decrease in its ability to support adhesion, even at very low concentrations of xylitol.

  13. Lactobacillus reuteri glyceraldehyde-3-phosphate dehydrogenase functions in adhesion to intestinal epithelial cells.

    Science.gov (United States)

    Zhang, Wen-Ming; Wang, Hai-Feng; Gao, Kan; Wang, Cong; Liu, Li; Liu, Jian-Xin

    2015-05-01

    This study was aimed to identify key surface proteins mediating the adhesion of lactobacilli to intestinal epithelial cells. By using Caco-2 and IPEC-J2 cells labeled with sulfo-NHS-biotin in the western blotting, a protein band of an approximately 37 kDa was detected on the surface layer of Lactobacillus reuteri strains ZJ616, ZJ617, ZJ621, and ZJ623 and Lactobacillus rhamnosus GG. Mass spectrometry analysis using the adhesion-related protein from L. reuteri ZJ617 showed that it was 100% homologous to the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) of L. reuteri JCM 1112 (GenBank: YP_001841377). The ability of L. reuteri ZJ617 to adhere to epithelial cells decreased significantly by treatment with LiCl or by blocking with an anti-GAPDH antibody, in comparison with the untreated strain (p reuteri ZJ617. The results indicated that the GAPDH protein of L. reuteri ZJ617 acts as an adhesion component that plays an important role in binding to the intestinal epithelial cells.

  14. Mechanisms of transcriptional regulation and prognostic significance of activated leukocyte cell adhesion molecule in cancer

    Directory of Open Access Journals (Sweden)

    Chen Hairu

    2010-10-01

    Full Text Available Abstract Background Activated leukocyte cell adhesion molecule (ALCAM is implicated in the prognosis of multiple cancers with low level expression associated with metastasis and early death in breast cancer. Despite this significance, mechanisms that regulate ALCAM gene expression and ALCAM's role in adhesion of pre-metastatic circulating tumor cells have not been defined. We studied ALCAM expression in 20 tumor cell lines by real-time PCR, western blot and immunochemistry. Epigenetic alterations of the ALCAM promoter were assessed using methylation-specific PCR and bisulfite sequencing. ALCAM's role in adhesion of tumor cells to the vascular wall was studied in isolated perfused lungs. Results A common site for transcription initiation of the ALCAM gene was identified and the ALCAM promoter sequenced. The promoter contains multiple cis-active elements including a functional p65 NF-κB motif, and it harbors an extensive array of CpG residues highly methylated exclusively in ALCAM-negative tumor cells. These CpG residues were modestly demethylated after 5-aza-2-deoxycytidine treatment. Restoration of high-level ALCAM expression using an ALCAM cDNA increased clustering of MDA-MB-435 tumor cells perfused through the pulmonary vasculature of ventilated rat lungs. Anti-ALCAM antibodies reduced the number of intravascular tumor cell clusters. Conclusion Our data suggests that loss of ALCAM expression, due in part to DNA methylation of extensive segments of the promoter, significantly impairs the ability of circulating tumor cells to adhere to each other, and may therefore promote metastasis. These findings offer insight into the mechanisms for down-regulation of ALCAM gene expression in tumor cells, and for the positive prognostic value of high-level ALCAM in breast cancer.

  15. Tunable swelling of polyelectrolyte multilayers in cell culture media for modulating NIH-3T3 cells adhesion.

    Science.gov (United States)

    Qi, Wei; Cai, Peng; Yuan, Wenjing; Wang, Hua

    2014-11-01

    For polyelectrolyte multilayers (PEMs) assembled by the layer-by-layer (LbL) assembly technique, their nanostructure and properties can be governed by many parameters during the building process. Here, it was demonstrated that the swelling of the PEMs containing poly(diallyldimethylammonium chloride) (PDDA) and poly(sodium 4-styrenesulfonate) (PSS) in cell culture media could be tuned with changing supporting salt solutions during the assembly process. Importantly, the influence of the PEMs assembled in different salt solutions on NIH-3T3 cell adhesion was observable. Specifically, the cells could possess a higher affinity for the films assembled in low salt concentration (i.e. 0.15M NaCl) or no salt, the poorly swelling films in cell culture media, which was manifested by the large cell spreading area and focal adhesions. In contrast, those were assembled in higher salt concentration, highly swelling films in cell culture media, were less attractive for the fibroblasts. As a result, the cell adhesion behaviors may be manipulated by tailoring the physicochemical properties of the films, which could be performed by changing the assembly conditions such as supporting salt concentration. Such a finding might promise a great potential in designing desired biomaterials for tissue engineering and regenerative medicine. © 2014 Wiley Periodicals, Inc.

  16. Mast cells facilitate local VEGF release as an early event in the pathogenesis of postoperative peritoneal adhesions.

    LENUS (Irish Health Repository)

    Cahill, Ronan A

    2012-02-03

    BACKGROUND: Peritoneal injury sustained at laparotomy may evoke local inflammatory responses that result in adhesion formation. Peritoneal mast cells are likely to initiate this process, whereas vascular permeability\\/endothelial growth factor (VEGF) may facilitate the degree to which subsequent adhesion formation occurs. METHODS: Mast cell deficient mice (WBB6F1-\\/-), along with their mast cell sufficient counterparts (WBB6F1+\\/+), underwent a standardized adhesion-inducing operation (AIS) with subsequent sacrifice and adhesion assessment 14 days later in a blinded fashion. Additional CD-1 and WBB6F1+\\/+, and WBB6F1-\\/- mice were killed 2, 6, 12, and 24 hours after operation for measurement of VEGF by ELISA in systemic serum and peritoneal lavage fluid. Two further groups of CD-1 mice underwent AIS and received either a single perioperative dose of anti-VEGF monoclonal antibody (10 mug\\/mouse) or a similar volume of IgG isotypic antibody and adhesion formation 2 weeks later was evaluated. RESULTS: WBB6F1-\\/- mice had less adhesions then did their WBB6F1+\\/+ counterparts (median [interquartile range] adhesion score 3[3-3] vs 1.5[1-2] respectively; P < .003). Local VEGF release peaked 6 hours after AIS in both WBB6F1+\\/+ and CD-1 mice whereas levels remained at baseline in WBB6F1-\\/- mice. CD-1 mice treated with a single dose of anti-VEGF therapy during operation had less adhesions than controls (2[1.25-2] vs 3[2.25-3], P = .0002). CONCLUSIONS: Mast cells and VEGF are central to the formation of postoperative intra-abdominal adhesions with mast cells being responsible, either directly or indirectly, for VEGF release into the peritoneal cavity after operation. In tandem with the recent clinical success of anti-VEGF monoclonal antibodies in oncologic practice, our observations suggest an intriguing avenue for research and development of anti-adhesion strategy.

  17. Growth hormone increases vascular cell adhesion molecule 1 expression

    DEFF Research Database (Denmark)

    Hansen, Troels Krarup; Fisker, Sanne; Dall, Rolf

    2004-01-01

    and 25 adult GH-deficient (GHD) patients randomized to GH treatment or placebo. Furthermore, we studied the direct effect of GH and IGF-I and serum from GH-treated subjects on basal and TNF alpha-stimulated expression of VCAM-1 and E-selectin on cultured human umbilical vein endothelial cells. Baseline...... levels of VCAM-1, but not E-selectin, were significantly lower in GHD patients than in healthy subjects (362 +/- 15 microg/liter vs. 516 +/- 21 microg/liter, P liter (95......% confidence interval: 95.0-208.7 microg/liter); P

  18. Kindlin-3 Is Essential for the Resting α4β1 Integrin-mediated Firm Cell Adhesion under Shear Flow Conditions.

    Science.gov (United States)

    Lu, Ling; Lin, ChangDong; Yan, ZhanJun; Wang, Shu; Zhang, YouHua; Wang, ShiHui; Wang, JunLei; Liu, Cui; Chen, JianFeng

    2016-05-06

    Integrin-mediated rolling and firm cell adhesion are two critical steps in leukocyte trafficking. Integrin α4β1 mediates a mixture of rolling and firm cell adhesion on vascular cell adhesion molecule-1 (VCAM-1) when in its resting state but only supports firm cell adhesion upon activation. The transition from rolling to firm cell adhesion is controlled by integrin activation. Kindlin-3 has been shown to bind to integrin β tails and trigger integrin activation via inside-out signaling. However, the role of kindlin-3 in regulating resting α4β1-mediated cell adhesion is not well characterized. Herein we demonstrate that kindlin-3 was required for the resting α4β1-mediated firm cell adhesion but not rolling adhesion. Knockdown of kindlin-3 significantly decreased the binding of kindlin-3 to β1 and down-regulated the binding affinity of the resting α4β1 to soluble VCAM-1. Notably, it converted the resting α4β1-mediated firm cell adhesion to rolling adhesion on VCAM-1 substrates, increased cell rolling velocity, and impaired the stability of cell adhesion. By contrast, firm cell adhesion mediated by Mn(2+)-activated α4β1 was barely affected by knockdown of kindlin-3. Structurally, lack of kindlin-3 led to a more bent conformation of the resting α4β1. Thus, kindlin-3 plays an important role in maintaining a proper conformation of the resting α4β1 to mediate both rolling and firm cell adhesion. Defective kindlin-3 binding to the resting α4β1 leads to a transition from firm to rolling cell adhesion on VCAM-1, implying its potential role in regulating the transition between integrin-mediated rolling and firm cell adhesion. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  19. Kindlin-3 Is Essential for the Resting α4β1 Integrin-mediated Firm Cell Adhesion under Shear Flow Conditions*

    Science.gov (United States)

    Lu, Ling; Lin, ChangDong; Yan, ZhanJun; Wang, Shu; Zhang, YouHua; Wang, ShiHui; Wang, JunLei; Liu, Cui; Chen, JianFeng

    2016-01-01

    Integrin-mediated rolling and firm cell adhesion are two critical steps in leukocyte trafficking. Integrin α4β1 mediates a mixture of rolling and firm cell adhesion on vascular cell adhesion molecule-1 (VCAM-1) when in its resting state but only supports firm cell adhesion upon activation. The transition from rolling to firm cell adhesion is controlled by integrin activation. Kindlin-3 has been shown to bind to integrin β tails and trigger integrin activation via inside-out signaling. However, the role of kindlin-3 in regulating resting α4β1-mediated cell adhesion is not well characterized. Herein we demonstrate that kindlin-3 was required for the resting α4β1-mediated firm cell adhesion but not rolling adhesion. Knockdown of kindlin-3 significantly decreased the binding of kindlin-3 to β1 and down-regulated the binding affinity of the resting α4β1 to soluble VCAM-1. Notably, it converted the resting α4β1-mediated firm cell adhesion to rolling adhesion on VCAM-1 substrates, increased cell rolling velocity, and impaired the stability of cell adhesion. By contrast, firm cell adhesion mediated by Mn2+-activated α4β1 was barely affected by knockdown of kindlin-3. Structurally, lack of kindlin-3 led to a more bent conformation of the resting α4β1. Thus, kindlin-3 plays an important role in maintaining a proper conformation of the resting α4β1 to mediate both rolling and firm cell adhesion. Defective kindlin-3 binding to the resting α4β1 leads to a transition from firm to rolling cell adhesion on VCAM-1, implying its potential role in regulating the transition between integrin-mediated rolling and firm cell adhesion. PMID:26994136

  20. Edaravone attenuates monocyte adhesion to endothelial cells induced by oxidized low-density lipoprotein.

    Science.gov (United States)

    Li, Zhijuan; Cheng, Jianxin; Wang, Liping

    2015-10-30

    Oxidized low-density lipoprotein (oxLDL) plays a vital role in recruitment of monocytes to endothelial cells, which is important during early stages of atherosclerosis development. Edaravone, a potent and novel scavenger of free radicals inhibiting hydroxyl radicals, has been clinically used to reduce the neuronal damage following ischemic stroke. In the present study, Edaravone was revealed to markedly reduce oxLDL-induced monocyte adhesion to human umbilical vein endothelial cells (HUVECs). The inhibitory mechanism of Edaravone was associated with suppression of the chemokine MCP-1 and adhesion molecule VCAM-1 and ICAM-1 expression. In addition, luciferase reporter assay results revealed that administration of Edaravone attenuated the increase in NF-κB transcriptional activity induced by oxLDL. Notably, it's also shown that Edaravone treatment blocked oxLDL induced p65 nuclear translocation in HUVECs. Results indicate that Edaravone negatively regulates endothelial inflammation. Copyright © 2015. Published by Elsevier Inc.

  1. Syndecans promote integrin-mediated adhesion of mesenchymal cells in two distinct pathways

    DEFF Research Database (Denmark)

    Whiteford, James; Behrends, Volker; Kirby, Hishani

    2007-01-01

    and signaling through the cytoplasmic domain of syndecan-4. Here an alternate pathway mediated by the extracellular domains of syndecans-2 and -4 is characterized that is independent of both heparan sulphate and syndecan signaling. This pathway is restricted to mesenchymal cells and was not seen in any...... epithelial cell line tested, apart from vascular endothelia. The syndecan ectodomains coated as substrates promoted integrin-dependent attachment, spreading and focal adhesion formation. Syndecan-4 null cells were competent, as were fibroblasts compromised in heparan sulphate synthesis that were unable...

  2. Fluorescence lifetime microscopy for monitoring cell adhesion using metal induced energy transfer

    Science.gov (United States)

    Hwang, Wonsang; Seo, JinWon; Song, Jun ho; Kim, DongEun; Won, YoungJae; Choi, In-Hong; Yoo, Kyung-Hwa; Kim, Dug Young

    2018-02-01

    A precise control and a reliable monitoring tool for the adhesion properties of a cell are very important in atherosclerosis studies. If endothelial cells in contact with the intracellular membrane are not attached securely, low-density lipoprotein (LDL) particles can enter into the inner membrane. It is therefore necessary to measure conditions under which endothelial cell detachment occurs. When a cell is attached to a metal thin film, the lifetime of a fluorescence probe attached to the membrane of the cell is reduced by the metal-induced energy transfer (MIET). Fluorescence lifetime imaging microscopy (FLIM) is used to monitor the attachment condition of a cell to a metal surface using FRET. However, this requires high numerical aperture (NA) objective lens because axial confocal resolution must be smaller than the cell thickness. This requirement limits the field of view of the measurement specimen. In this study we provides a new method which can measure adhesion properties of endothelial cells even with a low NA objective lens by resolving two lifetime components in FLIM.

  3. Proteomic Profiling of Neuroblastoma Cells Adhesion on Hyaluronic Acid-Based Surface for Neural Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Ming-Hui Yang

    2016-01-01

    Full Text Available The microenvironment of neuron cells plays a crucial role in regulating neural development and regeneration. Hyaluronic acid (HA biomaterial has been applied in a wide range of medical and biological fields and plays important roles in neural regeneration. PC12 cells have been reported to be capable of endogenous NGF synthesis and secretion. The purpose of this research was to assess the effect of HA biomaterial combining with PC12 cells conditioned media (PC12 CM in neural regeneration. Using SH-SY5Y cells as an experimental model, we found that supporting with PC12 CM enhanced HA function in SH-SY5Y cell proliferation and adhesion. Through RP-nano-UPLC-ESI-MS/MS analyses, we identified increased expression of HSP60 and RanBP2 in SH-SY5Y cells grown on HA-modified surface with cotreatment of PC12 CM. Moreover, we also identified factors that were secreted from PC12 cells and may promote SH-SY5Y cell proliferation and adhesion. Here, we proposed a biomaterial surface enriched with neurotrophic factors for nerve regeneration application.

  4. Enhanced Neural Cell Adhesion and Neurite Outgrowth on Graphene-Based Biomimetic Substrates

    Directory of Open Access Journals (Sweden)

    Suck Won Hong

    2014-01-01

    Full Text Available Neural cell adhesion and neurite outgrowth were examined on graphene-based biomimetic substrates. The biocompatibility of carbon nanomaterials such as graphene and carbon nanotubes (CNTs, that is, single-walled and multiwalled CNTs, against pheochromocytoma-derived PC-12 neural cells was also evaluated by quantifying metabolic activity (with WST-8 assay, intracellular oxidative stress (with ROS assay, and membrane integrity (with LDH assay. Graphene films were grown by using chemical vapor deposition and were then coated onto glass coverslips by using the scooping method. Graphene sheets were patterned on SiO2/Si substrates by using photolithography and were then covered with serum for a neural cell culture. Both types of CNTs induced significant dose-dependent decreases in the viability of PC-12 cells, whereas graphene exerted adverse effects on the neural cells just at over 62.5 ppm. This result implies that graphene and CNTs, even though they were the same carbon-based nanomaterials, show differential influences on neural cells. Furthermore, graphene-coated or graphene-patterned substrates were shown to substantially enhance the adhesion and neurite outgrowth of PC-12 cells. These results suggest that graphene-based substrates as biomimetic cues have good biocompatibility as well as a unique surface property that can enhance the neural cells, which would open up enormous opportunities in neural regeneration and nanomedicine.

  5. Roles of the cytoskeleton, cell adhesion and rho signalling in mechanosensing and mechanotransduction.

    Science.gov (United States)

    Ohashi, Kazumasa; Fujiwara, Sachiko; Mizuno, Kensaku

    2017-03-01

    All cells sense and respond to various mechanical forces in and mechanical properties of their environment. To respond appropriately, cells must be able to sense the location, direction, strength and duration of these forces. Recent progress in mechanobiology has provided a better understanding of the mechanisms of mechanoresponses underlying many cellular and developmental processes. Various roles of mechanoresponses in development and tissue homeostasis have been elucidated, and many molecules involved in mechanotransduction have been identified. However, the whole picture of the functions and molecular mechanisms of mechanotransduction remains to be understood. Recently, novel mechanisms for sensing and transducing mechanical stresses via the cytoskeleton, cell-substrate and cell-cell adhesions and related proteins have been identified. In this review, we outline the roles of the cytoskeleton, cell-substrate and cell-cell adhesions, and related proteins in mechanosensing and mechanotransduction. We also describe the roles and regulation of Rho-family GTPases in mechanoresponses. © The Authors 2017. Published by Oxford University Press on behalf of the Japanese Biochemical Society. All rights reserved.

  6. Quantitative measurements of intercellular adhesion between a macrophage and cancer cells using a cup-attached AFM chip.

    Science.gov (United States)

    Kim, Hyonchol; Yamagishi, Ayana; Imaizumi, Miku; Onomura, Yui; Nagasaki, Akira; Miyagi, Yohei; Okada, Tomoko; Nakamura, Chikashi

    2017-07-01

    Intercellular adhesion between a macrophage and cancer cells was quantitatively measured using atomic force microscopy (AFM). Cup-shaped metal hemispheres were fabricated using polystyrene particles as a template, and a cup was attached to the apex of the AFM cantilever. The cup-attached AFM chip (cup-chip) approached a murine macrophage cell (J774.2), the cell was captured on the inner concave of the cup, and picked up by withdrawing the cup-chip from the substrate. The cell-attached chip was advanced towards a murine breast cancer cell (FP10SC2), and intercellular adhesion between the two cells was quantitatively measured. To compare cell adhesion strength, the work required to separate two adhered cells (separation work) was used as a parameter. Separation work was almost 2-fold larger between a J774.2 cell and FP10SC2 cell than between J774.2 cell and three additional different cancer cells (4T1E, MAT-LyLu, and U-2OS), two FP10SC2 cells, or two J774.2 cells. FP10SC2 was established from 4T1E as a highly metastatic cell line, indicates separation work increased as the malignancy of cancer cells became higher. One possible explanation of the strong adhesion of macrophages to cancer cells observed in this study is that the measurement condition mimicked the microenvironment of tumor-associated macrophages (TAMs) in vivo, and J774.2 cells strongly expressed CD204, which is a marker of TAMs. The results of the present study, which were obtained by measuring cell adhesion strength quantitatively, indicate that the fabricated cup-chip is a useful tool for measuring intercellular adhesion easily and quantitatively. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Vasostatin-2 inhibits cell proliferation and adhesion in vascular smooth muscle cells, which are associated with the progression of atherosclerosis

    Energy Technology Data Exchange (ETDEWEB)

    Hou, Jianghong, E-mail: jianghonghou@163.com [Department of Cardiovascular, Weinan Center Hospital, The Middle of Victory Avenue, Linwei District, Weinan City 714000 (China); Xue, Xiaolin [Department of Cardiovascular, The First Affiliated Hospital, College of Medicine, Xi' an Jiaotong University, Xi' an 710061 (China); Li, Junnong [Department of Cardiovascular, Weinan Center Hospital, The Middle of Victory Avenue, Linwei District, Weinan City 714000 (China)

    2016-01-22

    Recently, the serum expression level of vasostatin-2 was found to be reduced and is being studied as an important indicator to assess the presence and severity of coronary artery disease; the functional properties of vasostatin-2 and its relationship with the development of atherosclerosis remains unclear. In this study, we attempted to detect the expression of vasostatin-2 and its impact on human vascular smooth muscle cells (VSMCs). Quantitative real-time PCR (qRT-PCR) and western blot were used to assess the expression level of vasostatin-2 in VSMCs between those from atherosclerosis and disease-free donors; we found that vasostatin-2 was significantly down-regulated in atherosclerosis patient tissues and cell lines. In addition, the over-expression of vasostatin-2 apparently inhibits cell proliferation and migration in VSMCs. Gain-of-function in vitro experiments further show that vasostatin-2 over-expression significantly inhibits inflammatory cytokines release in VSMCs. In addition, cell adhesion experimental analysis showed that soluble adhesion molecules (sICAM-1, sVCAM-1) had decreased expression when vasostatin-2 was over-expressed in VSMCs. Therefore, our results indicate that vasostatin-2 is an atherosclerosis-related factor that can inhibit cell proliferation, inflammatory response and cell adhesion in VSMCs. Taken together, our results indicate that vasostatin-2 could serve as a potential diagnostic biomarker and therapeutic option for human atherosclerosis in the near future. - Highlights: • Vasostatin-2 levels were down-regulated in atherosclerosis patient tissues and VSMCs. • Ectopic expression of vasostatin-2 directly affects cell proliferation and migration in vitro. • Ectopic expression of vasostatin-2 protein affects pro-inflammatory cytokines release in VSMCs. • Ectopic expression of vasostatin-2 protein affects cell adhesion in VSMCs.

  8. Probing living bacterial adhesion by single cell force spectroscopy using atomic force microscopy

    DEFF Research Database (Denmark)

    Zeng, Guanghong; Ogaki, Ryosuke; Regina, Viduthalai R.

    be considered. We have therefore developed a simple and versatile method to make single-cell bacterial probes for measuring single cell adhesion with atomic force microscopy (AFM).[1] A single-cell probe was readily made by picking up a bacterial cell from a glass surface using a tipless AFM cantilever coated...... random immobilization is obtained by submerging the cantilever in a bacterial suspension. The reported method provides a general platform for investigating single cell interactions of bacteria with different surfaces and other cells by AFM force spectroscopy, thus improving our understanding....... The strain-dependent susceptibility to bacterial colonization on conventional PLL-g-PEG illustrates how bacterial diversity challenges development of “universal” antifouling coatings, and AFM single-cell force spectroscopy was proven to be a powerful tool to provide insights into the molecular mechanisms...

  9. Quantifying bacterial adhesion on antifouling polymer brushes via single-cell force spectroscopy

    Czech Academy of Sciences Publication Activity Database

    Rodriguez-Emmenegger, Cesar; Janel, S.; de los Santos Pereira, Andres; Bruns, M.; Lafont, F.

    2015-01-01

    Roč. 6, č. 31 (2015), s. 5740-5751 ISSN 1759-9954 R&D Projects: GA ČR(CZ) GJ15-09368Y; GA MŠk(CZ) ED1.1.00/02.0109 Grant - others:OPPK(XE) CZ.2.16/3.1.00/21545 Program:OPPK Institutional support: RVO:61389013 Keywords : antifouling polymer brushes * single-cell force spectroscopy * bacterial adhesion Subject RIV: BO - Biophysics Impact factor: 5.687, year: 2015

  10. Soluble endothelial cell-selective adhesion molecule and incident cardiovascular events in a multiethnic population.

    Science.gov (United States)

    Ren, Hao-Yu; Khera, Amit; de Lemos, James A; Ayers, Colby R; Rohatgi, Anand

    2017-09-01

    Cell adhesion molecules are key regulators of atherosclerotic plaque development, but circulating levels of soluble fragments, such as intercellular adhesion molecule (sICAM-1) and vascular cell adhesion molecule (sVCAM-1), have yielded conflicting associations with atherosclerotic cardiovascular disease (ASCVD). Endothelial cell-selective adhesion molecule (ESAM) is expressed exclusively in platelets and endothelial cells, and soluble ESAM (sESAM) levels have been associated with prevalent subclinical atherosclerosis. We therefore hypothesized that sESAM would be associated with incident ASCVD. sESAM, sICAM-1, and sVCAM-1 were measured in 2,442 participants without CVD in the Dallas Heart Study, a probability-based population sample aged 30-65 years enrolled between 2000 and 2002. ASCVD was defined as first myocardial infarction, stroke, coronary revascularization, or CV death. A total of 162 ASCVD events were analyzed over 10.4 years. Increasing sESAM was associated with ASCVD, independent of risk factors (HR Q4 vs Q1: 2.7, 95% CI 1.6-4.6). Serial adjustment for renal function, sICAM-1, VCAM-1, and prevalent coronary calcium did not attenuate these associations. Continuous ESAM demonstrated similar findings (HR 1.31, 95% CI 1.2-1.4). Addition of sESAM to traditional risk factors improved discrimination and reclassification (delta c-index: P = .009; integrated-discrimination-improvement index P = .001; net reclassification index = 0.42, 95% CI 0.15-0.68). Neither sICAM-1 nor sVCAM-1 was independently associated with ASCVD. sESAM but not sICAM-1 or sVCAM-1 levels are associated with incident ASCVD. Further studies are warranted to investigate the role of sESAM in ASCVD. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. RhoA GTPase regulates radiation-induced alterations in endothelial cell adhesion and migration

    International Nuclear Information System (INIS)

    Rousseau, Matthieu; Gaugler, Marie-Hélène; Rodallec, Audrey; Bonnaud, Stéphanie; Paris, François; Corre, Isabelle

    2011-01-01

    Highlights: ► We explore the role of RhoA in endothelial cell response to ionizing radiation. ► RhoA is rapidly activated by single high-dose of radiation. ► Radiation leads to RhoA/ROCK-dependent actin cytoskeleton remodeling. ► Radiation-induced apoptosis does not require the RhoA/ROCK pathway. ► Radiation-induced alteration of endothelial adhesion and migration requires RhoA/ROCK. -- Abstract: Endothelial cells of the microvasculature are major target of ionizing radiation, responsible of the radiation-induced vascular early dysfunctions. Molecular signaling pathways involved in endothelial responses to ionizing radiation, despite being increasingly investigated, still need precise characterization. Small GTPase RhoA and its effector ROCK are crucial signaling molecules involved in many endothelial cellular functions. Recent studies identified implication of RhoA/ROCK in radiation-induced increase in endothelial permeability but other endothelial functions altered by radiation might also require RhoA proteins. Human microvascular endothelial cells HMEC-1, either treated with Y-27632 (inhibitor of ROCK) or invalidated for RhoA by RNA interference were exposed to 15 Gy. We showed a rapid radiation-induced activation of RhoA, leading to a deep reorganisation of actin cytoskeleton with rapid formation of stress fibers. Endothelial early apoptosis induced by ionizing radiation was not affected by Y-27632 pre-treatment or RhoA depletion. Endothelial adhesion to fibronectin and formation of focal adhesions increased in response to radiation in a RhoA/ROCK-dependent manner. Consistent with its pro-adhesive role, ionizing radiation also decreased endothelial cells migration and RhoA was required for this inhibition. These results highlight the role of RhoA GTPase in ionizing radiation-induced deregulation of essential endothelial functions linked to actin cytoskeleton.

  12. Peptide array-based screening of human mesenchymal stem cell-adhesive peptides derived from fibronectin type III domain

    International Nuclear Information System (INIS)

    Okochi, Mina; Nomura, Shigeyuki; Kaga, Chiaki; Honda, Hiroyuki

    2008-01-01

    Human mesenchymal stem cell-adhesive peptides were screened based on the amino acid sequence of fibronectin type III domain 8-11 (FN-III 8-11 ) using a peptide array synthesized by the Fmoc-chemistry. Using hexameric peptide library of FN-III 8-11 scan, we identified the ALNGR (Ala-Leu-Asn-Gly-Arg) peptide that induced cell adhesion as well as RGDS (Arg-Gly-Asp-Ser) peptide. After incubation for 2 h, approximately 68% of inoculated cells adhere to the ALNGR peptide disk. Adhesion inhibition assay with integrin antibodies showed that the ALNGR peptide interacts with integrin β1 but not with αvβ3, indicating that the receptors for ALNGR are different from RGDS. Additionally, the ALNGR peptide expressed cell specificities for adhesion: cell adhesion was promoted for fibroblasts but not for keratinocytes or endotherial cells. The ALNGR peptide induced cell adhesion and promoted cell proliferation without changing its property. It is therefore useful for the construction of functional biomaterials

  13. Receptor-like Molecules on Human Intestinal Epithelial Cells Interact with an Adhesion Factor from Lactobacillus reuteri.

    Science.gov (United States)

    Matsuo, Yosuke; Miyoshi, Yukihiro; Okada, Sanae; Satoh, Eiichi

    2012-01-01

    A surface protein of Lactobacillus reuteri, mucus adhesion-promoting protein (MapA), is considered to be an adhesion factor. MapA is expressed in L. reuteri strains and adheres to piglet gastric mucus, collagen type I, and human intestinal epithelial cells such as Caco-2. The aim of this study was to identify molecules that mediate the attachment of MapA from L. reuteri to the intestinal epithelial cell surface by investigating the adhesion of MapA to receptor-like molecules on Caco-2 cells. MapA-binding receptor-like molecules were detected in Caco-2 cell lysates by 2D-PAGE. Two proteins, annexin A13 (ANXA13) and paralemmin (PALM), were identified by MALDI TOF-MS. The results of a pull-down assay showed that MapA bound directly to ANXA13 and PALM. Fluorescence microscopy studies confirmed that MapA binding to ANXA13 and PALM was colocalized on the Caco-2 cell membrane. To evaluate whether ANXA13 and PALM are important for MapA adhesion, ANXA13 and PALM knockdown cell lines were established. The adhesion of MapA to the abovementioned cell lines was reduced compared with that to wild-type Caco-2 cells. These knockdown experiments established the importance of these receptor-like molecules in MapA adhesion.

  14. Evaluation of Encapsulant Adhesion to Surface Metallization of Photovoltaic Cells: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Tracy, Jared; Dauskardt, Reinhold; Bosco, Nick

    2017-06-14

    Delamination of encapsulant materials from PV cell surfaces often appears to originate at regions with metallization. Using a fracture mechanics based metrology, the adhesion of EVA encapsulant to screen printed silver metallization was evaluated. At room temperature, the fracture energy, Gc [J/m2], of the EVA/silver interface (952 J/m2) was ~70% lower than that of the EVA/AR coating (>2900 J/m2) and ~60% lower than that of the EVA to the surface of cell (2265 J/m2). After only 300 hours of damp heat aging, the adhesion energy of the silver interface dropped to and plateaued at ~50-60 J/m2, while that of the EVA/AR coating and EVA/cell remained mostly unchanged. Elemental surface analysis showed that the EVA separates from the silver in a purely adhesive manner, indicating that bonds at the interface were likely displaced in the presence of humidity and elevated temperature, and may explain the propensity for delamination to occur at metallized surfaces in the field.

  15. Effects of ethanol and NAP on cerebellar expression of the neural cell adhesion molecule L1.

    Directory of Open Access Journals (Sweden)

    Devon M Fitzgerald

    Full Text Available The neural cell adhesion molecule L1 is critical for brain development and plays a role in learning and memory in the adult. Ethanol inhibits L1-mediated cell adhesion and neurite outgrowth in cerebellar granule neurons (CGNs, and these actions might underlie the cerebellar dysmorphology of fetal alcohol spectrum disorders. The peptide NAP potently blocks ethanol inhibition of L1 adhesion and prevents ethanol teratogenesis. We used quantitative RT-PCR and Western blotting of extracts of cerebellar slices, CGNs, and astrocytes from postnatal day 7 (PD7 rats to investigate whether ethanol and NAP act in part by regulating the expression of L1. Treatment of cerebellar slices with 20 mM ethanol, 10(-12 M NAP, or both for 4 hours, 24 hours, and 10 days did not significantly affect L1 mRNA and protein levels. Similar treatment for 4 or 24 hours did not regulate L1 expression in primary cultures of CGNs and astrocytes, the predominant cerebellar cell types. Because ethanol also damages the adult cerebellum, we studied the effects of chronic ethanol exposure in adult rats. One year of binge drinking did not alter L1 gene and protein expression in extracts from whole cerebellum. Thus, ethanol does not alter L1 expression in the developing or adult cerebellum; more likely, ethanol disrupts L1 function by modifying its conformation and signaling. Likewise, NAP antagonizes the actions of ethanol without altering L1 expression.

  16. Tailoring Novel PTFE Surface Properties: Promoting Cell Adhesion and Antifouling Properties via a Wet Chemical Approach.

    Science.gov (United States)

    Gabriel, Matthias; Niederer, Kerstin; Becker, Marc; Raynaud, Christophe Michel; Vahl, Christian-Friedrich; Frey, Holger

    2016-05-18

    Many biomaterials used for tissue engineering applications lack cell-adhesiveness and, in addition, are prone to nonspecific adsorption of proteins. This is especially important for blood-contacting devices such as vascular grafts and valves where appropriate surface properties should inhibit the initial attachment of platelets and promote endothelial cell colonization. As a consequence, the long-term outcome of the implants would be improved and the need for anticoagulation therapy could be reduced or even abolished. Polytetrafluoroethylene (PTFE), a frequently used polymer for various medical applications, was wet-chemically activated and subsequently modified by grafting the endothelial cell (EC) specific peptide arginine-glutamic acid-aspartic acid-valine (REDV) using a bifunctional polyethylene glycol (PEG)-spacer (known to reduce platelet and nonspecific protein adhesion). Modified and control surfaces were both evaluated in terms of EC adhesion, colonization, and the attachment of platelets. In addition, samples underwent bacterial challenges. The results strongly suggested that PEG-mediated peptide immobilization renders PTFE an excellent substrate for cellular growth while simultaneously endowing the material with antifouling properties.

  17. Resveratrol and Estradiol Exert Disparate Effects on Cell Migration, Cell Surface Actin Structures, and Focal Adhesion Assembly in MDA-MB-231 Human Breast Cancer Cells

    Directory of Open Access Journals (Sweden)

    Nicolas G. Azios

    2005-02-01

    Full Text Available Resveratrol, a grape polyphenol, is thought to be a cancer preventive, yet its effects on metastatic breast cancer are relatively unknown. Since cancer cell invasion is dependent on cell migration, the chemotactic response of MDA-MB-231 metastatic human breast cancer cells to resveratrol, estradiol (E2, or epidermal growth factor (EGF was investigated. Resveratrol decreased while E2 and EGF increased directed cell migration. Resveratrol may inhibit cell migration by altering the cytoskeleton. Resveratrol induced a rapid global array of filopodia and decreased focal adhesions and focal adhesion kinase (FAK activity. E2 or EGF treatment did not affect filopodia extension but increased lamellipodia and associated focal adhesions that are integral for cell migration. Combined resveratrol and E2 treatment resulted in a filopodia and focal adhesion response similar to resveratrol alone. Combined resveratrol and EGF resulted in a lamellipodia and focal adhesion response similar to EGF alone. E2 and to a lesser extent resveratrol increased EGFR activity. The cytoskeletal changes and EGFR activity in response to E2 were blocked by EGFR1 inhibitor indicating that E2 may increase cell migration via crosstalk with EGFR signa