Extracellular matrix components direct porcine muscle stem cell behavior

Energy Technology Data Exchange (ETDEWEB)

Wilschut, Karlijn J. [Department of Farm Animal Health, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 104, 3584 CM, Utrecht (Netherlands); Haagsman, Henk P. [Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 1, 3584 CL, Utrecht (Netherlands); Roelen, Bernard A.J., E-mail: b.a.j.roelen@uu.nl [Department of Farm Animal Health, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 104, 3584 CM, Utrecht (Netherlands)

2010-02-01

In muscle tissue, extracellular matrix proteins, together with the vasculature system, muscle-residence cells and muscle fibers, create the niche for muscle stem cells. The niche is important in controlling proliferation and directing differentiation of muscle stem cells to sustain muscle tissue. Mimicking the extracellular muscle environment improves tools exploring the behavior of primary muscle cells. Optimizing cell culture conditions to maintain muscle commitment is important in stem cell-based studies concerning toxicology screening, ex vivo skeletal muscle tissue engineering and in the enhancement of clinical efficiency. We used the muscle extracellular matrix proteins collagen type I, fibronectin, laminin, and also gelatin and Matrigel as surface coatings of tissue culture plastic to resemble the muscle extracellular matrix. Several important factors that determine myogenic commitment of the primary muscle cells were characterized by quantitative real-time RT-PCR and immunofluorescence. Adhesion of high PAX7 expressing satellite cells was improved if the cells were cultured on fibronectin or laminin coatings. Cells cultured on Matrigel and laminin coatings showed dominant integrin expression levels and exhibited an activated Wnt pathway. Under these conditions both stem cell proliferation and myogenic differentiation capacity were superior if compared to cells cultured on collagen type I, fibronectin and gelatin. In conclusion, Matrigel and laminin are the preferred coatings to sustain the proliferation and myogenic differentiation capacity of the primary porcine muscle stem cells, when cells are removed from their natural environment for in vitro culture.

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.

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

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...

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.

Palmitate-induced inflammatory pathways in human adipose microvascular endothelial cells promote monocyte adhesion and impair insulin transcytosis.

Science.gov (United States)

Pillon, Nicolas J; Azizi, Paymon M; Li, Yujin E; Liu, Jun; Wang, Changsen; Chan, Kenny L; Hopperton, Kathryn E; Bazinet, Richard P; Heit, Bryan; Bilan, Philip J; Lee, Warren L; Klip, Amira

2015-07-01

Obesity is associated with inflammation and immune cell recruitment to adipose tissue, muscle and intima of atherosclerotic blood vessels. Obesity and hyperlipidemia are also associated with tissue insulin resistance and can compromise insulin delivery to muscle. The muscle/fat microvascular endothelium mediates insulin delivery and facilitates monocyte transmigration, yet its contribution to the consequences of hyperlipidemia is poorly understood. Using primary endothelial cells from human adipose tissue microvasculature (HAMEC), we investigated the effects of physiological levels of fatty acids on endothelial inflammation and function. Expression of cytokines and adhesion molecules was measured by RT-qPCR. Signaling pathways were evaluated by pharmacological manipulation and immunoblotting. Surface expression of adhesion molecules was determined by immunohistochemistry. THP1 monocyte interaction with HAMEC was measured by cell adhesion and migration across transwells. Insulin transcytosis was measured by total internal reflection fluorescence microscopy. Palmitate, but not palmitoleate, elevated the expression of IL-6, IL-8, TLR2 (Toll-like receptor 2), and intercellular adhesion molecule 1 (ICAM-1). HAMEC had markedly low fatty acid uptake and oxidation, and CD36 inhibition did not reverse the palmitate-induced expression of adhesion molecules, suggesting that inflammation did not arise from palmitate uptake/metabolism. Instead, inhibition of TLR4 to NF-κB signaling blunted palmitate-induced ICAM-1 expression. Importantly, palmitate-induced surface expression of ICAM-1 promoted monocyte binding and transmigration. Conversely, palmitate reduced insulin transcytosis, an effect reversed by TLR4 inhibition. In summary, palmitate activates inflammatory pathways in primary microvascular endothelial cells, impairing insulin transport and increasing monocyte transmigration. This behavior may contribute in vivo to reduced tissue insulin action and enhanced tissue

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...

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.

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

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.

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.

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

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.

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.

Zyxin Is Involved In Regulation Of Mechanotransduction In Arteriole Smooth Muscle Cells

Directory of Open Access Journals (Sweden)

Zhe eSun

2012-12-01

Full Text Available Zyxin is a focal adhesion protein that has been implicated in the modulation of cell adhesion and motility, and is hypothesized to be a mechano-sensor in integrin-mediated responses to mechanical force. To test the functional role of zyxin in the mechanotransduction of microvascular smooth muscle cells (VSMC, we utilized atomic force microscopy (AFM to apply localized pulling forces to VSMC through a fibronectin (FN focal adhesion induced by a FN-coated bead on cell surface. Application of force with the AFM induced an increase of zyxin accumulation at the site of the FN-bead focal adhesion that accompanied the VSMC contractile response. Whereas, reduction of zyxin expression by using a zyxin-shRNA construct abolished the VSMC contractile response to AFM pulling forces, even though the zyxin-silenced VSMCs displayed increased adhesion to FN in both AFM adhesion assays and cell adhesion assays. The reduced zyxin expression significantly impaired cell spreading and reorganization of the actin cytoskeleton that could indicate a possible underlying reason for the loss of a contractile response to mechanical force. Consistent with these observations, zyxin silencing also resulted in reduced expression of Rac1, which plays an important role in the actin reorganization in VSMC, but increased TRIP6 and FAK expression, the latter being a major protein that promote cell adhesion. In conclusion, these data support an important enabling role for zyxin in VSMCs ability to mechanically respond to applied force.

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

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

Adhesion of axolemmal fragments to Schwann cells: a signal- and target-specific process closely linked to axolemmal induction of Schwann cell mitosis

International Nuclear Information System (INIS)

Sobue, G.; Pleasure, D.

1985-01-01

Radioiodinated rat CNS axolemmal fragments adhered to cultured rat Schwann cells by a time-, temperature-, and concentration-dependent process independent of extracellular ionized calcium. Adhesion showed target and signal specificity; axolemmal fragments adhered to endoneurial or dermal fibroblasts to a much lesser extent than to Schwann cells, and plasma membrane fragments from skeletal muscle, erythrocytes, or PNS myelin adhered to Schwann cells to a lesser extent than did axolemmal fragments. Brief trypsinization removed 94 to 97% of bound radioactivity from Schwann cells previously incubated with 125 I-axolemmal fragments for up to 24 hr, indicating that adhesion was largely a surface phenomenon rather than the result of rapid internalization of axolemmal fragments by the Schwann cells. When adhesion was compared to the axolemmal mitogenic response of Schwann cells, the concentration of axolemmal fragments yielding half-maximal adhesion was the same as the concentration producing half-maximal stimulation of Schwann cell mitosis. Trypsin digestion, homogenization, or heating of axolemmal fragments before application to cultured Schwann cells diminished adhesion and axolemmal fragment-induced stimulation of Schwann cell mitosis in a parallel fashion. Whereas adhesion of axolemmal fragments to the surfaces of the cultured Schwann cells reached completion within 4 hr in this assay system, induction of Schwann cell mitosis by the fragments required contact with Schwann cells for a minimum of 6 to 8 hr and reached a maximum when the axolemmal fragments had adhered to the Schwann cells for 24 hr or more

Micro- and nanostructured Al{sub 2}O{sub 3} surfaces for controlled vascular endothelial and smooth muscle cell adhesion and proliferation

Energy Technology Data Exchange (ETDEWEB)

Aktas, Cenk, E-mail: cenk.aktas@inm-gmbh.de [INM - Leibniz Institute for New Materials, CVD/Biosurfaces Division, 66123 Saarbruecken (Germany); Doerrschuck, Eva; Schuh, Cathrin [Clinic of Paediatric Cardiology, Saarland University, Building 9, 66424 Homburg (Germany); Miro, Marina Martinez; Lee, Juseok [INM - Leibniz Institute for New Materials, CVD/Biosurfaces Division, 66123 Saarbruecken (Germany); Puetz, Norbert; Wennemuth, Gunther [Department of Anatomy and Cell Biology, Saarland University, Building 61, 66424 Homburg (Germany); Metzger, Wolfgang; Oberringer, Martin [Department of Trauma-, Hand- and Reconstructive Surgery, Saarland University, Building 57, 66424 Homburg (Germany); Veith, Michael [INM - Leibniz Institute for New Materials, CVD/Biosurfaces Division, 66123 Saarbruecken (Germany); Department of Inorganic Chemistry, University of Saarland, Building C 4 1, 66123 Saarbruecken (Germany); Abdul-Khaliq, Hashim [Clinic of Paediatric Cardiology, Saarland University, Building 9, 66424 Homburg (Germany)

2012-07-01

The effect of the micro- and nanotopography on vascular cell-surface interaction is investigated using nano- and microstructured Al{sub 2}O{sub 3} as model substrate. Two different nanostructured Al{sub 2}O{sub 3} surfaces composed of low density (LD) and high density (HD) nanowires (NWs) were synthesized by chemical vapour deposition (CVD) and commercially available microstructured Al{sub 2}O{sub 3} plates were used for comparison. A clear diverging response of human umbilical vein endothelial cells (HUVEC) and human umbilical vein smooth muscle cells (HUVSMC) was observed on these nano- and microstructured surfaces. LD Al{sub 2}O{sub 3} NWs seem to enhance the proliferation of HUVECs selectively. This selective control of the cell-surface interaction by topography may represent a key issue for the future stent material design. - Highlights: Black-Right-Pointing-Pointer Nanostructured alumina surfaces triggers selective adhesion and proliferation of endothelial cells. Black-Right-Pointing-Pointer Catalyst free synthesis of nanowires. Black-Right-Pointing-Pointer Topography induces selective cell response.

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...

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

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....

Tenascin-Y, a component of distinctive connective tissues, supports muscle cell growth.

Science.gov (United States)

Hagios, C; Brown-Luedi, M; Chiquet-Ehrismann, R

1999-12-15

Chicken tenascin-Y is an extracellular matrix protein most closely related to the mammalian tenascin-X. It is highly expressed in the connective tissue of skeletal muscle (C. Hagios, M. Koch, J. Spring, M. Chiquet, and R. Chiquet-Ehrismann, 1996, J. Cell Biol. 134, 1499-1512). Here we demonstrate the presence of tenascin-Y in specific areas of the connective tissues in developing lung, kidney, and skin. In skin tenascin-Y shows a complementary expression pattern to tenascin-C, whereas in the lung and kidney the sites of expression are partly overlapping. Tenascin-Y is also present in embryonic skeletal muscle where it is expressed in the developing connective tissue in between the muscle fibers. This connective tissue is also the major site of alpha5 integrin expression. We purified recombinantly expressed tenascin-Y and tested its effect on cell adhesion and its influence on muscle cell growth and differentiation. C2C12 myoblasts were able to adhere to tenascin-Y and showed extensive formation of actin-rich processes without generation of stress fibers. Furthermore, we found that tenascin-Y influenced cell morphology of chick embryo fibroblasts over prolonged times in culture and that it supports primary muscle cell growth and restricts muscle cell differentiation. Copyright 1999 Academic Press.

Adhesion, Growth, and Maturation of Vascular Smooth Muscle Cells on Low-Density Polyethylene Grafted with Bioactive Substances

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Martin Parizek

2013-01-01

Full Text Available The attractiveness of synthetic polymers for cell colonization can be affected by physical, chemical, and biological modification of the polymer surface. In this study, low-density polyethylene (LDPE was treated by an Ar+ plasma discharge and then grafted with biologically active substances, namely, glycine (Gly, polyethylene glycol (PEG, bovine serum albumin (BSA, colloidal carbon particles (C, or BSA+C. All modifications increased the oxygen content, the wettability, and the surface free energy of the materials compared to the pristine LDPE, but these changes were most pronounced in LDPE with Gly or PEG, where all the three values were higher than in the only plasma-treated samples. When seeded with vascular smooth muscle cells (VSMCs, the Gly- or PEG-grafted samples increased mainly the spreading and concentration of focal adhesion proteins talin and vinculin in these cells. LDPE grafted with BSA or BSA+C showed a similar oxygen content and similar wettability, as the samples only treated with plasma, but the nano- and submicron-scale irregularities on their surface were more pronounced and of a different shape. These samples promoted predominantly the growth, the formation of a confluent layer, and phenotypic maturation of VSMC, demonstrated by higher concentrations of contractile proteins alpha-actin and SM1 and SM2 myosins. Thus, the behavior of VSMC on LDPE can be regulated by the type of bioactive substances that are grafted.

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.

Dystroglycan versatility in cell adhesion: a tale of multiple motifs

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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.

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...

Iduronic acid in chondroitin/dermatan sulfate affects directional migration of aortic smooth muscle cells.

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Barbara Bartolini

Full Text Available Aortic smooth muscle cells produce chondroitin/dermatan sulfate (CS/DS proteoglycans that regulate extracellular matrix organization and cell behavior in normal and pathological conditions. A unique feature of CS/DS proteoglycans is the presence of iduronic acid (IdoA, catalyzed by two DS epimerases. Functional ablation of DS-epi1, the main epimerase in these cells, resulted in a major reduction of IdoA both on cell surface and in secreted CS/DS proteoglycans. Downregulation of IdoA led to delayed ability to re-populate wounded areas due to loss of directional persistence of migration. DS-epi1-/- aortic smooth muscle cells, however, had not lost the general property of migration showing even increased speed of movement compared to wild type cells. Where the cell membrane adheres to the substratum, stress fibers were denser whereas focal adhesion sites were fewer. Total cellular expression of focal adhesion kinase (FAK and phospho-FAK (pFAK was decreased in mutant cells compared to control cells. As many pathological conditions are dependent on migration, modulation of IdoA content may point to therapeutic strategies for diseases such as cancer and atherosclerosis.

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)

Role of Cbl-associated protein/ponsin in receptor tyrosine kinase signaling and cell adhesion

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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.

A contractile and counterbalancing adhesion system controls the 3D shape of crawling cells.

Science.gov (United States)

Burnette, Dylan T; Shao, Lin; Ott, Carolyn; Pasapera, Ana M; Fischer, Robert S; Baird, Michelle A; Der Loughian, Christelle; Delanoe-Ayari, Helene; Paszek, Matthew J; Davidson, Michael W; Betzig, Eric; Lippincott-Schwartz, Jennifer

2014-04-14

How adherent and contractile systems coordinate to promote cell shape changes is unclear. Here, we define a counterbalanced adhesion/contraction model for cell shape control. Live-cell microscopy data showed a crucial role for a contractile meshwork at the top of the cell, which is composed of actin arcs and myosin IIA filaments. The contractile actin meshwork is organized like muscle sarcomeres, with repeating myosin II filaments separated by the actin bundling protein α-actinin, and is mechanically coupled to noncontractile dorsal actin fibers that run from top to bottom in the cell. When the meshwork contracts, it pulls the dorsal fibers away from the substrate. This pulling force is counterbalanced by the dorsal fibers' attachment to focal adhesions, causing the fibers to bend downward and flattening the cell. This model is likely to be relevant for understanding how cells configure themselves to complex surfaces, protrude into tight spaces, and generate three-dimensional forces on the growth substrate under both healthy and diseased conditions.

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.

A muscle stem cell for every muscle: variability of satellite cell biology among different muscle groups

Science.gov (United States)

Randolph, Matthew E.; Pavlath, Grace K.

2015-01-01

The human body contains approximately 640 individual skeletal muscles. Despite the fact that all of these muscles are composed of striated muscle tissue, the biology of these muscles and their associated muscle stem cell populations are quite diverse. Skeletal muscles are affected differentially by various muscular dystrophies (MDs), such that certain genetic mutations specifically alter muscle function in only a subset of muscles. Additionally, defective muscle stem cells have been implicated in the pathology of some MDs. The biology of muscle stem cells varies depending on the muscles with which they are associated. Here we review the biology of skeletal muscle stem cell populations of eight different muscle groups. Understanding the biological variation of skeletal muscles and their resident stem cells could provide valuable insight into mechanisms underlying the susceptibility of certain muscles to myopathic disease. PMID:26500547

Bone Marrow Stromal Cells Generate Muscle Cells and Repair Muscle Degeneration

Science.gov (United States)

Dezawa, Mari; Ishikawa, Hiroto; Itokazu, Yutaka; Yoshihara, Tomoyuki; Hoshino, Mikio; Takeda, Shin-ichi; Ide, Chizuka; Nabeshima, Yo-ichi

2005-07-01

Bone marrow stromal cells (MSCs) have great potential as therapeutic agents. We report a method for inducing skeletal muscle lineage cells from human and rat general adherent MSCs with an efficiency of 89%. Induced cells differentiated into muscle fibers upon transplantation into degenerated muscles of rats and mdx-nude mice. The induced population contained Pax7-positive cells that contributed to subsequent regeneration of muscle upon repetitive damage without additional transplantation of cells. These MSCs represent a more ready supply of myogenic cells than do the rare myogenic stem cells normally found in muscle and bone marrow.

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...

The adhesion and growth of vascular smooth muscle cells in cultures on carboranethiol-modified gold films

Czech Academy of Sciences Publication Activity Database

Pařízek, Martin; Baše, Tomáš; Londesborough, Michael Geoffrey Stephen; Lisá, Věra; Bačáková, Lucie

2008-01-01

Roč. 11, 81-84 (2008), s. 117-119 ISSN 1429-7248 R&D Projects: GA AV ČR(CZ) KAN400480701 Institutional research plan: CEZ:AV0Z50110509; CEZ:AV0Z40320502 Keywords : bioactive coating * cell adhesion * cell growth Subject RIV: EI - Biotechnology ; Bionics

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....

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

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).

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

Changes in satellite cells in human skeletal muscle after a single bout of high intensity exercise

DEFF Research Database (Denmark)

Crameri, Regina M; Langberg, Henning; Magnusson, Peter

2004-01-01

increase in mononuclear cells staining for the neural cell adhesion molecule (N-CAM) and fetal antigen 1 (FA1) were observed within the exercised human vastus lateralis muscle on days 4 and 8 post exercise. In addition, a significant increase in the concentration of the FA1 protein was determined...

Titanium Implant Impairment and Surrounding Muscle Cell Death Following High-Salt Diet: An In Vivo Study.

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Mathieu Lecocq

Full Text Available High-salt consumption has been widely described as a risk factor for cardiovascular, renal and bone functions. In the present study, the extent to which high-salt diet could influence Ti6Al4V implant surface characteristic, its adhesion to rat tibial crest, and could modify muscle cell viability of two surrounding muscles, was investigated in vivo. These parameters have also been assessed following a NMES (neuro-myoelectrostimulation program similar to that currently used in human care following arthroplasty.After a three-week diet, a harmful effect on titanium implant surface and muscle cell viability was noted. This is probably due to salt corrosive effect on metal and then release of toxic substance around biologic tissue. Moreover, if the use of NMES with high-salt diet induced muscles damages, the latter were higher when implant was added. Unexpectedly, higher implant-to-bone adhesion was found for implanted animals receiving salt supplementation.Our in vivo study highlights the potential dangerous effect of high-salt diet in arthroplasty based on titanium prosthesis. This effect appears to be more important when high-salt diet is combined with NMES.

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).

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

Stimulatory interactions between human coronary smooth muscle cells and dendritic cells.

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Sara Paccosi

Full Text Available Despite inflammatory and immune mechanisms participating to atherogenesis and dendritic cells (DCs driving immune and non-immune tissue injury response, the interactions between DCs and vascular smooth muscle cells (VSMCs possibly relevant to vascular pathology including atherogenesis are still unclear. To address this issue, immature DCs (iDCs generated from CD14+ cells isolated from healthy donors were matured either with cytokines (mDCs, or co-cultured (ccDCs with human coronary artery VSMCs (CASMCs using transwell chambers. Co-culture induced DC immunophenotypical and functional maturation similar to cytokines, as demonstrated by flow cytometry and mixed lymphocyte reaction. In turn, factors from mDCs and ccDCs induced CASMC migration. MCP-1 and TNFα, secreted from DCs, and IL-6 and MCP-1, secreted from CASMCs, were primarily involved. mDCs adhesion to CASMCs was enhanced by CASMC pre-treatment with IFNγ and TNFα ICAM-1 and VCAM-1 were involved, since the expression of specific mRNAs for these molecules increased and adhesion was inhibited by neutralizing antibodies to the counter-receptors CD11c and CD18. Adhesion was also inhibited by CASMC pre-treatment with the HMG-CoA-reductase inhibitor atorvastatin and the PPARγ agonist rosiglitazone, which suggests a further mechanism for the anti-inflammatory action of these drugs. Adhesion of DCs to VSMCs was shown also in vivo in rat carotid 7 to 21 days after crush and incision injury. The findings indicate that DCs and VSMCs can interact with reciprocal stimulation, possibly leading to perpetuate inflammation and vascular wall remodelling, and that the interaction is enhanced by a cytokine-rich inflammatory environment and down-regulated by HMGCoA-reductase inhibitors and PPARγ agonists.

Mechanisms of adhesion and subsequent actions of a haematopoietic stem cell line, HPC-7, in the injured murine intestinal microcirculation in vivo.

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Dean P J Kavanagh

Full Text Available Although haematopoietic stem cells (HSCs migrate to injured gut, therapeutic success clinically remains poor. This has been partially attributed to limited local HSC recruitment following systemic injection. Identifying site specific adhesive mechanisms underpinning HSC-endothelial interactions may provide important information on how to enhance their recruitment and thus potentially improve therapeutic efficacy. This study determined (i the integrins and inflammatory cyto/chemokines governing HSC adhesion to injured gut and muscle (ii whether pre-treating HSCs with these cyto/chemokines enhanced their adhesion and (iii whether the degree of HSC adhesion influenced their ability to modulate leukocyte recruitment.Adhesion of HPC-7, a murine HSC line, to ischaemia-reperfused (IR injured mouse gut or cremaster muscle was monitored intravitally. Critical adhesion molecules were identified by pre-treating HPC-7 with blocking antibodies to CD18 and CD49d. To identify cyto/chemokines capable of recruiting HPC-7, adhesion was monitored following tissue exposure to TNF-α, IL-1β or CXCL12. The effects of pre-treating HPC-7 with these cyto/chemokines on surface integrin expression/clustering, adhesion to ICAM-1/VCAM-1 and recruitment in vivo was also investigated. Endogenous leukocyte adhesion following HPC-7 injection was again determined intravitally.IR injury increased HPC-7 adhesion in vivo, with intestinal adhesion dependent upon CD18 and muscle adhesion predominantly relying on CD49d. Only CXCL12 pre-treatment enhanced HPC-7 adhesion within injured gut, likely by increasing CD18 binding to ICAM-1 and/or CD18 surface clustering on HPC-7. Leukocyte adhesion was reduced at 4 hours post-reperfusion, but only when local HPC-7 adhesion was enhanced using CXCL12.This data provides evidence that site-specific molecular mechanisms govern HPC-7 adhesion to injured tissue. Importantly, we show that HPC-7 adhesion is a modulatable event in IR injury and

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

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

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.

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...

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....

Potential of laryngeal muscle regeneration using induced pluripotent stem cell-derived skeletal muscle cells.

Science.gov (United States)

Dirja, Bayu Tirta; Yoshie, Susumu; Ikeda, Masakazu; Imaizumi, Mitsuyoshi; Nakamura, Ryosuke; Otsuki, Koshi; Nomoto, Yukio; Wada, Ikuo; Hazama, Akihiro; Omori, Koichi

2016-01-01

Conclusion Induced pluripotent stem (iPS) cells may be a new potential cell source for laryngeal muscle regeneration in the treatment of vocal fold atrophy after recurrent laryngeal nerve paralysis. Objectives Unilateral vocal fold paralysis can lead to degeneration, atrophy, and loss of force of the thyroarytenoid muscle. At present, there are some treatments such as thyroplasty, arytenoid adduction, and vocal fold injection. However, such treatments cannot restore reduced mass of the thyroarytenoid muscle. iPS cells have been recognized as supplying a potential resource for cell transplantation. The aim of this study was to assess the effectiveness of the use of iPS cells for the regeneration of laryngeal muscle through the evaluation of both in vitro and in vivo experiments. Methods Skeletal muscle cells were generated from tdTomato-labeled iPS cells using embryoid body formation. Differentiation into skeletal muscle cells was analyzed by gene expression and immunocytochemistry. The tdTomato-labeled iPS cell-derived skeletal muscle cells were transplanted into the left atrophied thyroarytenoid muscle. To evaluate the engraftment of these cells after transplantation, immunohistochemistry was performed. Results The tdTomato-labeled iPS cells were successfully differentiated into skeletal muscle cells through an in vitro experiment. These cells survived in the atrophied thyroarytenoid muscle after transplantation.

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.

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....

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.

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

Self-organization of muscle cell structure and function.

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Anna Grosberg

2011-02-01

Full Text Available The organization of muscle is the product of functional adaptation over several length scales spanning from the sarcomere to the muscle bundle. One possible strategy for solving this multiscale coupling problem is to physically constrain the muscle cells in microenvironments that potentiate the organization of their intracellular space. We hypothesized that boundary conditions in the extracellular space potentiate the organization of cytoskeletal scaffolds for directed sarcomeregenesis. We developed a quantitative model of how the cytoskeleton of neonatal rat ventricular myocytes organizes with respect to geometric cues in the extracellular matrix. Numerical results and in vitro assays to control myocyte shape indicated that distinct cytoskeletal architectures arise from two temporally-ordered, organizational processes: the interaction between actin fibers, premyofibrils and focal adhesions, as well as cooperative alignment and parallel bundling of nascent myofibrils. Our results suggest that a hierarchy of mechanisms regulate the self-organization of the contractile cytoskeleton and that a positive feedback loop is responsible for initiating the break in symmetry, potentiated by extracellular boundary conditions, is required to polarize the contractile cytoskeleton.

Self-organization of muscle cell structure and function.

Science.gov (United States)

Grosberg, Anna; Kuo, Po-Ling; Guo, Chin-Lin; Geisse, Nicholas A; Bray, Mark-Anthony; Adams, William J; Sheehy, Sean P; Parker, Kevin Kit

2011-02-01

The organization of muscle is the product of functional adaptation over several length scales spanning from the sarcomere to the muscle bundle. One possible strategy for solving this multiscale coupling problem is to physically constrain the muscle cells in microenvironments that potentiate the organization of their intracellular space. We hypothesized that boundary conditions in the extracellular space potentiate the organization of cytoskeletal scaffolds for directed sarcomeregenesis. We developed a quantitative model of how the cytoskeleton of neonatal rat ventricular myocytes organizes with respect to geometric cues in the extracellular matrix. Numerical results and in vitro assays to control myocyte shape indicated that distinct cytoskeletal architectures arise from two temporally-ordered, organizational processes: the interaction between actin fibers, premyofibrils and focal adhesions, as well as cooperative alignment and parallel bundling of nascent myofibrils. Our results suggest that a hierarchy of mechanisms regulate the self-organization of the contractile cytoskeleton and that a positive feedback loop is responsible for initiating the break in symmetry, potentiated by extracellular boundary conditions, is required to polarize the contractile cytoskeleton.

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.).

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...

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

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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.

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.

Prostaglandins in Cancer Cell Adhesion, Migration, and Invasion

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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.

A Tendon Cell Specific RNAi Screen Reveals Novel Candidates Essential for Muscle Tendon Interaction.

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Prabhat Tiwari

Full Text Available Tendons are fibrous connective tissue which connect muscles to the skeletal elements thus acting as passive transmitters of force during locomotion and provide appropriate body posture. Tendon-derived cues, albeit poorly understood, are necessary for proper muscle guidance and attachment during development. In the present study, we used dorsal longitudinal muscles of Drosophila and their tendon attachment sites to unravel the molecular nature of interactions between muscles and tendons. We performed a genetic screen using RNAi-mediated knockdown in tendon cells to find out molecular players involved in the formation and maintenance of myotendinous junction and found 21 candidates out of 2507 RNAi lines screened. Of these, 19 were novel molecules in context of myotendinous system. Integrin-βPS and Talin, picked as candidates in this screen, are known to play important role in the cell-cell interaction and myotendinous junction formation validating our screen. We have found candidates with enzymatic function, transcription activity, cell adhesion, protein folding and intracellular transport function. Tango1, an ER exit protein involved in collagen secretion was identified as a candidate molecule involved in the formation of myotendinous junction. Tango1 knockdown was found to affect development of muscle attachment sites and formation of myotendinous junction. Tango1 was also found to be involved in secretion of Viking (Collagen type IV and BM-40 from hemocytes and fat cells.

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.

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.

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

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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.

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.

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.

Satellite Cells and the Muscle Stem Cell Niche

Science.gov (United States)

Yin, Hang; Price, Feodor

2013-01-01

Adult skeletal muscle in mammals is a stable tissue under normal circumstances but has remarkable ability to repair after injury. Skeletal muscle regeneration is a highly orchestrated process involving the activation of various cellular and molecular responses. As skeletal muscle stem cells, satellite cells play an indispensible role in this process. The self-renewing proliferation of satellite cells not only maintains the stem cell population but also provides numerous myogenic cells, which proliferate, differentiate, fuse, and lead to new myofiber formation and reconstitution of a functional contractile apparatus. The complex behavior of satellite cells during skeletal muscle regeneration is tightly regulated through the dynamic interplay between intrinsic factors within satellite cells and extrinsic factors constituting the muscle stem cell niche/microenvironment. For the last half century, the advance of molecular biology, cell biology, and genetics has greatly improved our understanding of skeletal muscle biology. Here, we review some recent advances, with focuses on functions of satellite cells and their niche during the process of skeletal muscle regeneration. PMID:23303905

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.

Skeletal Muscle Cell Induction from Pluripotent Stem Cells

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Yusaku Kodaka

2017-01-01

Full Text Available Embryonic stem cells (ESCs and induced pluripotent stem cells (iPSCs have the potential to differentiate into various types of cells including skeletal muscle cells. The approach of converting ESCs/iPSCs into skeletal muscle cells offers hope for patients afflicted with the skeletal muscle diseases such as the Duchenne muscular dystrophy (DMD. Patient-derived iPSCs are an especially ideal cell source to obtain an unlimited number of myogenic cells that escape immune rejection after engraftment. Currently, there are several approaches to induce differentiation of ESCs and iPSCs to skeletal muscle. A key to the generation of skeletal muscle cells from ESCs/iPSCs is the mimicking of embryonic mesodermal induction followed by myogenic induction. Thus, current approaches of skeletal muscle cell induction of ESCs/iPSCs utilize techniques including overexpression of myogenic transcription factors such as MyoD or Pax3, using small molecules to induce mesodermal cells followed by myogenic progenitor cells, and utilizing epigenetic myogenic memory existing in muscle cell-derived iPSCs. This review summarizes the current methods used in myogenic differentiation and highlights areas of recent improvement.

The FRIABLE1 gene product affects cell adhesion in Arabidopsis.

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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.

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...

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.

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

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.

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.

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

Macrophages improve survival, proliferation and migration of engrafted myogenic precursor cells into MDX skeletal muscle.

Directory of Open Access Journals (Sweden)

Pierre-François Lesault

Full Text Available Transplantation of muscle precursor cells is of therapeutic interest for focal skeletal muscular diseases. However, major limitations of cell transplantation are the poor survival, expansion and migration of the injected cells. The massive and early death of transplanted myoblasts is not fully understood although several mechanisms have been suggested. Various attempts have been made to improve their survival or migration. Taking into account that muscle regeneration is associated with the presence of macrophages, which are helpful in repairing the muscle by both cleansing the debris and deliver trophic cues to myoblasts in a sequential way, we attempted in the present work to improve myoblast transplantation by coinjecting macrophages. The present data showed that in the 5 days following the transplantation, macrophages efficiently improved: i myoblast survival by limiting their massive death, ii myoblast expansion within the tissue and iii myoblast migration in the dystrophic muscle. This was confirmed by in vitro analyses showing that macrophages stimulated myoblast adhesion and migration. As a result, myoblast contribution to regenerating host myofibres was increased by macrophages one month after transplantation. Altogether, these data demonstrate that macrophages are beneficial during the early steps of myoblast transplantation into skeletal muscle, showing that coinjecting these stromal cells may be used as a helper to improve the efficiency of parenchymal cell engraftment.

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.

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.

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.

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

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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.

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.

Adhesion and growth of vascular smooth muscle cells in cultures on bioactive RGD peptide-carrying polylactides

Czech Academy of Sciences Publication Activity Database

Bačáková, Lucie; Filová, Elena; Kubies, Dana; Machová, Luďka; Proks, Vladimír; Malinova, V.; Rypáček, František

2007-01-01

Roč. 18, č. 7 (2007), s. 1317-1323 ISSN 0957-4530 R&D Projects: GA AV ČR IAA4050202; GA AV ČR(CZ) 1QS500110564 Institutional research plan: CEZ:AV0Z50110509; CEZ:AV0Z40500505 Keywords : tissue engineering * integrin-mediated cell adhesion * bioartificial tissue Subject RIV: EI - Biotechnology ; Bionics Impact factor: 1.581, year: 2007

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)

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.

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.

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.

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.

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.

Amino acid sequence preferences to control cell-specific organization of endothelial cells, smooth muscle cells, and fibroblasts.

Science.gov (United States)

Kanie, Kei; Kato, Ryuji; Zhao, Yingzi; Narita, Yuji; Okochi, Mina; Honda, Hiroyuki

2011-06-01

Effective surface modification with biocompatible molecules is known to be effective in reducing the life-threatening risks related to artificial cardiovascular implants. In recent strategies in regenerative medicine, the enhancement and support of natural repair systems at the site of injury by designed biocompatible molecules have succeeded in rapid and effective injury repair. Therefore, such a strategy could also be effective for rapid endothelialization of cardiovascular implants to lower the risk of thrombosis and stenosis. To achieve this enhancement of the natural repair system, a biomimetic molecule that mimics proper cellular organization at the implant location is required. In spite of the fact that many reported peptides have cell-attracting properties on material surfaces, there have been few peptides that could control cell-specific adhesion. For the advanced cardiovascular implants, peptides that can mimic the natural mechanism that controls cell-specific organization have been strongly anticipated. To obtain such peptides, we hypothesized the cellular bias toward certain varieties of amino acids and examined the cell preference (in terms of adhesion, proliferation, and protein attraction) of varieties and of repeat length on SPOT peptide arrays. To investigate the role of specific peptides in controlling the organization of various cardiovascular-related cells, we compared endothelial cells (ECs), smooth muscle cells (SMCs), and fibroblasts (FBs). A clear, cell-specific preference was found for amino acids (longer than 5-mer) using three types of cells, and the combinational effect of the physicochemical properties of the residues was analyzed to interpret the mechanism. Copyright © 2011 European Peptide Society and John Wiley & Sons, Ltd.

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...

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.

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.

Fibulin-1 suppression of fibronectin-regulated cell adhesion and motility.

Science.gov (United States)

Twal, W O; Czirok, A; Hegedus, B; Knaak, C; Chintalapudi, M R; Okagawa, H; Sugi, Y; Argraves, W S

2001-12-01

Fibulin-1 is an extracellular matrix protein often associated with fibronectin (FN) in vivo. In this study, the ability of fibulin-1 to modulate adhesion, spreading and motility-promoting activities of FN was investigated. Fibulin-1 was found to have pronounced inhibitory effects on the cell attachment and spreading promoted by FN. Fibulin-1 was also found to inhibit the motility of a variety of cell types on FN substrata. For example, the FN-dependent haptotactic motility of breast carcinoma (MDA MB231) cells, epidermal carcinoma (A431), melanoma (A375 SM), rat pulmonary aortic smooth muscle cells (PAC1) and Chinese hamster ovary (CHO) cells was inhibited by the presence of fibulin-1 bound to FN-coated Boyden chamber membranes. Cells transfected to overproduce fibulin-1 displayed reduced velocity, distance of movement and persistence time on FN substrata. Similarly, the incorporation of fibulin-1 into FN-containing type I collagen gels inhibited the invasion of endocardial cushion mesenchymal cells migrating from cultured embryonic heart explants. By contrast, incorporation of fibulin-1 into collagen gels lacking FN had no effect on the migration of endocardial cushion cells. These results suggest that the motility-suppressive effects of fibulin-1 might be FN specific. Furthermore, such effects are cell-type specific, in that the migration of gingival fibroblasts and endothelial cells on FN substrata is not responsive to fibulin-1. Additional studies found that the mechanism for the motility-suppressive effects of fibulin-1 does not involve perturbations of interactions between alpha5beta1 or alpha4 integrins, or heparan sulfate proteoglycans with FN. However, fibulin-1 was found to inhibit extracellular signal regulated kinase (ERK) activation and to suppress phosphorylation of myosin heavy chain. This ability to influence signal transduction cascades that modulate the actin-myosin motor complex might be the basis for the effects of fibulin-1 on adhesion and

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.

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.

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...

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.

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.

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...

The emerin-binding transcription factor Lmo7 is regulated by association with p130Cas at focal adhesions

Directory of Open Access Journals (Sweden)

Michele A. Wozniak

2013-08-01

Full Text Available Loss of function mutations in the nuclear inner membrane protein, emerin, cause X-linked Emery-Dreifuss muscular dystrophy (X-EDMD. X-EDMD is characterized by contractures of major tendons, skeletal muscle weakening and wasting, and cardiac conduction system defects. The transcription factor Lmo7 regulates muscle- and heart-relevant genes and is inhibited by binding to emerin, suggesting Lmo7 misregulation contributes to EDMD disease. Lmo7 associates with cell adhesions and shuttles between the plasma membrane and nucleus, but the regulation and biological consequences of this dual localization were unknown. We report endogenous Lmo7 also associates with focal adhesions in cells, and both co-localizes and co-immunoprecipitates with p130Cas, a key signaling component of focal adhesions. Lmo7 nuclear localization and transcriptional activity increased significantly in p130Cas-null MEFs, suggesting Lmo7 is negatively regulated by p130Cas-dependent association with focal adhesions. These results support EDMD models in which Lmo7 is a downstream mediator of integrin-dependent signaling that allows tendon cells and muscles to adapt to and withstand mechanical stress.

Muscle Satellite Cell Protein Teneurin‐4 Regulates Differentiation During Muscle Regeneration

Science.gov (United States)

Ishii, Kana; Suzuki, Nobuharu; Mabuchi, Yo; Ito, Naoki; Kikura, Naomi; Fukada, So‐ichiro; Okano, Hideyuki; Takeda, Shin'ichi

2015-01-01

Abstract Satellite cells are maintained in an undifferentiated quiescent state, but during muscle regeneration they acquire an activated stage, and initiate to proliferate and differentiate as myoblasts. The transmembrane protein teneurin‐4 (Ten‐4) is specifically expressed in the quiescent satellite cells; however, its cellular and molecular functions remain unknown. We therefore aimed to elucidate the function of Ten‐4 in muscle satellite cells. In the tibialis anterior (TA) muscle of Ten‐4‐deficient mice, the number and the size of myofibers, as well as the population of satellite cells, were reduced with/without induction of muscle regeneration. Furthermore, we found an accelerated activation of satellite cells in the regenerated Ten‐4‐deficient TA muscle. The cell culture analysis using primary satellite cells showed that Ten‐4 suppressed the progression of myogenic differentiation. Together, our findings revealed that Ten‐4 functions as a crucial player in maintaining the quiescence of muscle satellite cells. Stem Cells 2015;33:3017–3027 PMID:26013034

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

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.

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.

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.

Muscle satellite cell heterogeneity and self-renewal

Science.gov (United States)

Motohashi, Norio; Asakura, Atsushi

2014-01-01

Adult skeletal muscle possesses extraordinary regeneration capacities. After muscle injury or exercise, large numbers of newly formed muscle fibers are generated within a week as a result of expansion and differentiation of a self-renewing pool of muscle stem cells termed muscle satellite cells. Normally, satellite cells are mitotically quiescent and reside beneath the basal lamina of muscle fibers. Upon regeneration, satellite cells are activated, and give rise to daughter myogenic precursor cells. After several rounds of proliferation, these myogenic precursor cells contribute to the formation of new muscle fibers. During cell division, a minor population of myogenic precursor cells returns to quiescent satellite cells as a self-renewal process. Currently, accumulating evidence has revealed the essential roles of satellite cells in muscle regeneration and the regulatory mechanisms, while it still remains to be elucidated how satellite cell self-renewal is molecularly regulated and how satellite cells are important in aging and diseased muscle. The number of satellite cells is decreased due to the changing niche during ageing, resulting in attenuation of muscle regeneration capacity. Additionally, in Duchenne muscular dystrophy (DMD) patients, the loss of satellite cell regenerative capacity and decreased satellite cell number due to continuous needs for satellite cells lead to progressive muscle weakness with chronic degeneration. Thus, it is necessary to replenish muscle satellite cells continuously. This review outlines recent findings regarding satellite cell heterogeneity, asymmetric division and molecular mechanisms in satellite cell self-renewal which is crucial for maintenance of satellite cells as a muscle stem cell pool throughout life. In addition, we discuss roles in the stem cell niche for satellite cell maintenance, as well as related cell therapies for approaching treatment of DMD. PMID:25364710

Muscle Satellite Cell Heterogeneity and Self-Renewal

Directory of Open Access Journals (Sweden)

Norio eMotohashi

2014-01-01

Full Text Available Adult skeletal muscle possesses extraordinary regeneration capacities. After muscle injury or exercise, large numbers of newly formed muscle fibers are generated within a week as a result of expansion and differentiation of a self-renewing pool of muscle stem cells termed muscle satellite cells. Normally, satellite cells are mitotically quiescent and reside beneath the basal lamina of muscle fibers. Upon regeneration, satellite cells are activated, and give rise to daughter myogenic precursor cells. After several rounds of proliferation, these myogenic precursor cells contribute to the formation of new muscle fibers. During cell division, a minor population of myogenic precursor cells returns to quiescent satellite cells as a self-renewal process. Currently, accumulating evidence has revealed the essential roles of satellite cells in muscle regeneration and the regulatory mechanisms, while it still remains to be elucidated how satellite cell self-renewal is molecularly regulated and how satellite cells are important in aging and diseased muscle. The number of satellite cells is decreased due to the changing niche during ageing, resulting in attenuation of muscle regeneration capacity. Additionally, in Duchenne muscular dystrophy (DMD patients, the loss of satellite cell regenerative capacity and decreased satellite cell number due to continuous needs for satellite cells lead to progressive muscle weakness with chronic degeneration. Thus, it is necessary to replenish muscle satellite cells continuously. This review outlines recent findings regarding satellite cell heterogeneity, asymmetric division and molecular mechanisms in satellite cell self-renewal which is crucial for maintenance of satellite cells as a muscle stem cell pool throughout life. In addition, we discuss roles in the stem cell niche for satellite cell maintenance, as well as related cell therapies for approaching treatment of DMD.

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.

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

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....

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...

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.

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.

Lipopolysaccharide induces VCAM-1 expression and neutrophil adhesion to human tracheal smooth muscle cells: Involvement of Src/EGFR/PI3-K/Akt pathway

International Nuclear Information System (INIS)

Lin, W.-N.; Luo, S.-F.; Wu, C.-B.; Lin, C.-C.; Yang, C.-M.

2008-01-01

In our previous study, LPS has been shown to induce vascular cell adhesion molecule-1(VCAM-1) expression through MAPKs and NF-κB in human tracheal smooth muscle cells (HTSMCs). In addition to these pathways, the non-receptor tyrosine kinases (Src), EGF receptor (EGFR), and phosphatidylinositol 3-kinase (PI3K) have been shown to be implicated in the expression of several inflammatory target proteins. Here, we reported that LPS-induced up-regulation of VCAM-1 enhanced the adhesion of neutrophils onto HTSMC monolayer, which was inhibited by LY294002 and wortmannin. LPS stimulated phosphorylation of protein tyrosine kinases including Src, PYK2, and EGFR, which were further confirmed using specific anti-phospho-Src, PYK2, or EGFR Ab, respectively, revealed by Western blotting. LPS-stimulated Src, PYK2, EGFR, and Akt phosphorylation and VCAM-1 expression were attenuated by the inhibitors of Src (PP1), EGFR (AG1478), PI3-K (LY294002 and wortmannin), and Akt (SH-5), respectively, or transfection with siRNAs of Src or Akt and shRNA of p110. LPS-induced VCAM-1 expression was also blocked by pretreatment with curcumin (a p300 inhibitor) or transfection with p300 siRNA. LPS-stimulated Akt activation translocated into nucleus and associated with p300 and VCAM-1 promoter region was further confirmed by immunofluorescence, immunoprecipitation, and chromatin immunoprecipitation assays. This association of Akt and p300 to VCAM-1 promoter was inhibited by pretreatment with PP1, AG1478, wortmannin, and SH-5. LPS-induced p300 activation enhanced VCAM-1 promoter activity and VCAM-1 mRNA expression. These results suggested that in HTSMCs, Akt phosphorylation mediated through transactivation of Src/PYK2/EGFR promoted the transcriptional p300 activity and eventually led to VCAM-1 expression induced by LPS

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.

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.

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

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.

Muscle Satellite Cell Protein Teneurin-4 Regulates Differentiation During Muscle Regeneration.

Science.gov (United States)

Ishii, Kana; Suzuki, Nobuharu; Mabuchi, Yo; Ito, Naoki; Kikura, Naomi; Fukada, So-Ichiro; Okano, Hideyuki; Takeda, Shin'ichi; Akazawa, Chihiro

2015-10-01

Satellite cells are maintained in an undifferentiated quiescent state, but during muscle regeneration they acquire an activated stage, and initiate to proliferate and differentiate as myoblasts. The transmembrane protein teneurin-4 (Ten-4) is specifically expressed in the quiescent satellite cells; however, its cellular and molecular functions remain unknown. We therefore aimed to elucidate the function of Ten-4 in muscle satellite cells. In the tibialis anterior (TA) muscle of Ten-4-deficient mice, the number and the size of myofibers, as well as the population of satellite cells, were reduced with/without induction of muscle regeneration. Furthermore, we found an accelerated activation of satellite cells in the regenerated Ten-4-deficient TA muscle. The cell culture analysis using primary satellite cells showed that Ten-4 suppressed the progression of myogenic differentiation. Together, our findings revealed that Ten-4 functions as a crucial player in maintaining the quiescence of muscle satellite cells. © 2015 The Authors STEM CELLS published by Wiley Periodicals, Inc. on behalf of AlphaMed Press.

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.

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.

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.

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.

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.

The Skeletal Muscle Satellite Cell

Science.gov (United States)

2011-01-01

The skeletal muscle satellite cell was first described and named based on its anatomic location between the myofiber plasma and basement membranes. In 1961, two independent studies by Alexander Mauro and Bernard Katz provided the first electron microscopic descriptions of satellite cells in frog and rat muscles. These cells were soon detected in other vertebrates and acquired candidacy as the source of myogenic cells needed for myofiber growth and repair throughout life. Cultures of isolated myofibers and, subsequently, transplantation of single myofibers demonstrated that satellite cells were myogenic progenitors. More recently, satellite cells were redefined as myogenic stem cells given their ability to self-renew in addition to producing differentiated progeny. Identification of distinctively expressed molecular markers, in particular Pax7, has facilitated detection of satellite cells using light microscopy. Notwithstanding the remarkable progress made since the discovery of satellite cells, researchers have looked for alternative cells with myogenic capacity that can potentially be used for whole body cell-based therapy of skeletal muscle. Yet, new studies show that inducible ablation of satellite cells in adult muscle impairs myofiber regeneration. Thus, on the 50th anniversary since its discovery, the satellite cell’s indispensable role in muscle repair has been reaffirmed. PMID:22147605

Adhesion kinetics of human primary monocytes, dendritic cells, and macrophages: Dynamic cell adhesion measurements with a label-free optical biosensor and their comparison with end-point assays.

Science.gov (United States)

Orgovan, Norbert; Ungai-Salánki, Rita; Lukácsi, Szilvia; Sándor, Noémi; Bajtay, Zsuzsa; Erdei, Anna; Szabó, Bálint; Horvath, Robert

2016-09-01

Monocytes, dendritic cells (DCs), and macrophages (MFs) are closely related immune cells that differ in their main functions. These specific functions are, to a considerable degree, determined by the differences in the adhesion behavior of the cells. To study the inherently and essentially dynamic aspects of the adhesion of monocytes, DCs, and MFs, dynamic cell adhesion assays were performed with a high-throughput label-free optical biosensor [Epic BenchTop (BT)] on surfaces coated with either fibrinogen (Fgn) or the biomimetic copolymer PLL-g-PEG-RGD. Cell adhesion profiles typically reached their maximum at ∼60 min after cell seeding, which was followed by a monotonic signal decrease, indicating gradually weakening cell adhesion. According to the biosensor response, cell types could be ordered by increasing adherence as monocytes, MFs, and DCs. Notably, all three cell types induced a larger biosensor signal on Fgn than on PLL-g-PEG-RGD. To interpret this result, the molecular layers were characterized by further exploiting the potentials of the biosensor: by measuring the adsorption signal induced during the surface coating procedure, the authors could estimate the surface density of adsorbed molecules and, thus, the number of binding sites potentially presented for the adhesion receptors. Surfaces coated with PLL-g-PEG-RGD presented less RGD sites, but was less efficient in promoting cell spreading than those coated with Fgn; hence, other binding sites in Fgn played a more decisive role in determining cell adherence. To support the cell adhesion data obtained with the biosensor, cell adherence on Fgn-coated surfaces 30-60 min after cell seeding was measured with three complementary techniques, i.e., with (1) a fluorescence-based classical adherence assay, (2) a shear flow chamber applying hydrodynamic shear stress to wash cells away, and (3) an automated micropipette using vacuum-generated fluid flow to lift cells up. These techniques confirmed the results

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...

Mast cell chymase induces smooth muscle cell apoptosis by disrupting NF-κB-mediated survival signaling

International Nuclear Information System (INIS)

Leskinen, Markus J.; Heikkilae, Hanna M.; Speer, Mei Y.; Hakala, Jukka K.; Laine, Mika; Kovanen, Petri T.; Lindstedt, Ken A.

2006-01-01

Chymase released from activated mast cells induces apoptosis of vascular smooth muscle cells (SMCs) in vitro by degrading the pericellular matrix component fibronectin, so causing disruption of focal adhesion complexes and Akt dephosphorylation, which are necessary for cell adhesion and survival. However, the molecular mechanisms of chymase-mediated apoptosis downstream of Akt have remained elusive. Here, we show by means of RT-PCR, Western blotting, EMSA, immunocytochemistry and confocal microscopy, that chymase induces SMC apoptosis by disrupting NF-κB-mediated survival signaling. Following chymase treatment, the translocation of active NF-κB/p65 to the nucleus was partly abolished and the amount of nuclear p65 was reduced. Pretreatment of SMCs with chymase also inhibited LPS- and IL-1β-induced nuclear translocation of p65. The chymase-induced degradation of p65 was mediated by active caspases. Loss of NF-κB-mediated transactivation resulted in downregulation of bcl-2 mRNA and protein expression, leading to mitochondrial swelling and release of cytochrome c. The apoptotic process involved activation of both caspase 9 and caspase 8. The results reveal that, by disrupting the NF-κB-mediated survival-signaling pathway, activated chymase-secreting mast cells can mediate apoptosis of cultured arterial SMCs. Since activated mast cells colocalize with apoptotic SMCs in vulnerable areas of human atherosclerotic plaques, they may participate in the weakening and rupture of atherosclerotic plaques

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.

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

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

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.

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...

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.

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.

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....

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...

Platelet rich plasma promotes skeletal muscle cell migration in association with up-regulation of FAK, paxillin, and F-Actin formation.

Science.gov (United States)

Tsai, Wen-Chung; Yu, Tung-Yang; Lin, Li-Ping; Lin, Mioa-Sui; Tsai, Ting-Ta; Pang, Jong-Hwei S

2017-11-01

Platelet rich plasma (PRP) contains various cytokines and growth factors which may be beneficial to the healing process of injured muscle. The aim of this study was to investigate the effect and molecular mechanism of PRP on migration of skeletal muscle cells. Skeletal muscle cells intrinsic to Sprague-Dawley rats were treated with PRP. The cell migration was evaluated by transwell filter migration assay and electric cell-substrate impedance sensing. The spreading of cells was evaluated microscopically. The formation of filamentous actin (F-actin) cytoskeleton was assessed by immunofluorescence staining. The protein expressions of paxillin and focal adhesion kinase (FAK) were assessed by Western blot analysis. Transfection of paxillin small-interfering RNA (siRNAs) to muscle cells was performed to validate the role of paxillin in PRP-mediated promotion of cell migration. Dose-dependently PRP promotes migration of and spreading and muscle cells. Protein expressions of paxillin and FAK were up-regulated dose-dependently. F-actin formation was also enhanced by PRP treatment. Furthermore, the knockdown of paxillin expression impaired the effect of PRP to promote cell migration. It was concluded that PRP promoting migration of muscle cells is associated with up-regulation of proteins expression of paxillin and FAK as well as increasing F-actin formation. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2506-2512, 2017. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

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.

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...

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.))

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

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.

Human eosinophil–airway smooth muscle cell interactions

Directory of Open Access Journals (Sweden)

J. Margaret Hughes

2000-01-01

Full Text Available Eosinophils are present throughout the airway wall of asthmatics. The nature of the interaction between human airway smooth muscle cells (ASMC and eosinophils was investigated in this study. We demonstrated, using light microscopy, that freshly isolated eosinophils from healthy donors rapidly attach to ASMC in vitro. Numbers of attached eosinophils were highest at 2 h, falling to 50% of maximum by 20 h. Eosinophil attachment at 2 h was reduced to 72% of control by anti-VCAM-1, and to 74% at 20 h by anti-ICAM-1. Pre-treatment of ASMC for 24 h with TNF-α, 10 nM, significantly increased eosinophil adhesion to 149 and 157% of control after 2 and 20 h. These results provide evidence that eosinophil interactions with ASMC involve VCAM-1 and ICAM-1 and are modulated by TNF-α.

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

A Human Pluripotent Stem Cell Model of Facioscapulohumeral Muscular Dystrophy-Affected Skeletal Muscles.

Science.gov (United States)

Caron, Leslie; Kher, Devaki; Lee, Kian Leong; McKernan, Robert; Dumevska, Biljana; Hidalgo, Alejandro; Li, Jia; Yang, Henry; Main, Heather; Ferri, Giulia; Petek, Lisa M; Poellinger, Lorenz; Miller, Daniel G; Gabellini, Davide; Schmidt, Uli

2016-09-01

: Facioscapulohumeral muscular dystrophy (FSHD) represents a major unmet clinical need arising from the progressive weakness and atrophy of skeletal muscles. The dearth of adequate experimental models has severely hampered our understanding of the disease. To date, no treatment is available for FSHD. Human embryonic stem cells (hESCs) potentially represent a renewable source of skeletal muscle cells (SkMCs) and provide an alternative to invasive patient biopsies. We developed a scalable monolayer system to differentiate hESCs into mature SkMCs within 26 days, without cell sorting or genetic manipulation. Here we show that SkMCs derived from FSHD1-affected hESC lines exclusively express the FSHD pathogenic marker double homeobox 4 and exhibit some of the defects reported in FSHD. FSHD1 myotubes are thinner when compared with unaffected and Becker muscular dystrophy myotubes, and differentially regulate genes involved in cell cycle control, oxidative stress response, and cell adhesion. This cellular model will be a powerful tool for studying FSHD and will ultimately assist in the development of effective treatments for muscular dystrophies. This work describes an efficient and highly scalable monolayer system to differentiate human pluripotent stem cells (hPSCs) into skeletal muscle cells (SkMCs) and demonstrates disease-specific phenotypes in SkMCs derived from both embryonic and induced hPSCs affected with facioscapulohumeral muscular dystrophy. This study represents the first human stem cell-based cellular model for a muscular dystrophy that is suitable for high-throughput screening and drug development. ©AlphaMed Press.

Satellite cells in human skeletal muscle plasticity

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Tim eSnijders

2015-10-01

Full Text Available Skeletal muscle satellite cells are considered to play a crucial role in muscle fiber maintenance, repair and remodelling. Our knowledge of the role of satellite cells in muscle fiber adaptation has traditionally relied on in vitro cell and in vivo animal models. Over the past decade, a genuine effort has been made to translate these results to humans under physiological conditions. Findings from in vivo human studies suggest that satellite cells play a key role in skeletal muscle fiber repair/remodelling in response to exercise. Mounting evidence indicates that aging has a profound impact on the regulation of satellite cells in human skeletal muscle. Yet, the precise role of satellite cells in the development of muscle fiber atrophy with age remains unresolved. This review seeks to integrate recent results from in vivo human studies on satellite cell function in muscle fiber repair/remodelling in the wider context of satellite cell biology whose literature is largely based on animal and cell models.

Satellite cells in human skeletal muscle plasticity.

Science.gov (United States)

Snijders, Tim; Nederveen, Joshua P; McKay, Bryon R; Joanisse, Sophie; Verdijk, Lex B; van Loon, Luc J C; Parise, Gianni

2015-01-01

Skeletal muscle satellite cells are considered to play a crucial role in muscle fiber maintenance, repair and remodeling. Our knowledge of the role of satellite cells in muscle fiber adaptation has traditionally relied on in vitro cell and in vivo animal models. Over the past decade, a genuine effort has been made to translate these results to humans under physiological conditions. Findings from in vivo human studies suggest that satellite cells play a key role in skeletal muscle fiber repair/remodeling in response to exercise. Mounting evidence indicates that aging has a profound impact on the regulation of satellite cells in human skeletal muscle. Yet, the precise role of satellite cells in the development of muscle fiber atrophy with age remains unresolved. This review seeks to integrate recent results from in vivo human studies on satellite cell function in muscle fiber repair/remodeling in the wider context of satellite cell biology whose literature is largely based on animal and cell models.

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�

Regulatory T cells and skeletal muscle regeneration.

Science.gov (United States)

Schiaffino, Stefano; Pereira, Marcelo G; Ciciliot, Stefano; Rovere-Querini, Patrizia

2017-02-01

Skeletal muscle regeneration results from the activation and differentiation of myogenic stem cells, called satellite cells, located beneath the basal lamina of the muscle fibers. Inflammatory and immune cells have a crucial role in the regeneration process. Acute muscle injury causes an immediate transient wave of neutrophils followed by a more persistent infiltration of M1 (proinflammatory) and M2 (anti-inflammatory/proregenerative) macrophages. New studies show that injured muscle is also infiltrated by a specialized population of regulatory T (Treg) cells, which control both the inflammatory response, by promoting the M1-to-M2 switch, and the activation of satellite cells. Treg cells accumulate in injured muscle in response to specific cytokines, such as IL-33, and promote muscle growth by releasing growth factors, such as amphiregulin. Muscle repair during aging is impaired due to reduced number of Treg cells and can be enhanced by IL-33 supplementation. Migration of Treg cells could also contribute to explain the effect of heterochronic parabiosis, whereby muscle regeneration of aged mice can be improved by a parabiotically linked young partners. In mdx dystrophin-deficient mice, a model of human Duchenne muscular dystrophy, muscle injury, and inflammation is mitigated by expansion of the Treg-cell population but exacerbated by Treg-cell depletion. These findings support the notion that immunological mechanisms are not only essential in the response to pathogenic microbes and tumor cells but also have a wider homeostatic role in tissue repair, and open new perspectives for boosting muscle growth in chronic muscle disease and during aging. © 2016 Federation of European Biochemical Societies.

Bacterial Vaginosis Bacterial and Epithelial Cell Adhesion Molecules

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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.

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.

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.

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.

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

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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

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

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).

Cell adhesion signaling regulates RANK expression in osteoclast precursors.

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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

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.

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.

The Role of Immunoglobulin Superfamily Cell Adhesion Molecules in Cancer Metastasis

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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.

Loss of niche-satellite cell interactions in syndecan-3 null mice alters muscle progenitor cell homeostasis improving muscle regeneration.

Science.gov (United States)

Pisconti, Addolorata; Banks, Glen B; Babaeijandaghi, Farshad; Betta, Nicole Dalla; Rossi, Fabio M V; Chamberlain, Jeffrey S; Olwin, Bradley B

2016-01-01

The skeletal muscle stem cell niche provides an environment that maintains quiescent satellite cells, required for skeletal muscle homeostasis and regeneration. Syndecan-3, a transmembrane proteoglycan expressed in satellite cells, supports communication with the niche, providing cell interactions and signals to maintain quiescent satellite cells. Syndecan-3 ablation unexpectedly improves regeneration in repeatedly injured muscle and in dystrophic mice, accompanied by the persistence of sublaminar and interstitial, proliferating myoblasts. Additionally, muscle aging is improved in syndecan-3 null mice. Since syndecan-3 null myofiber-associated satellite cells downregulate Pax7 and migrate away from the niche more readily than wild type cells, syxndecan-3 appears to regulate satellite cell homeostasis and satellite cell homing to the niche. Manipulating syndecan-3 provides a promising target for development of therapies to enhance muscle regeneration in muscular dystrophies and in aged muscle.

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.

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

Oral Gingival Cell Cigarette Smoke Exposure Induces Muscle Cell Metabolic Disruption

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Andrea C. Baeder

2016-01-01

Full Text Available Cigarette smoke exposure compromises health through damaging multiple physiological systems, including disrupting metabolic function. The purpose of this study was to determine the role of oral gingiva in mediating the deleterious metabolic effects of cigarette smoke exposure on skeletal muscle metabolic function. Using an in vitro conditioned medium cell model, skeletal muscle cells were incubated with medium from gingival cells treated with normal medium or medium containing suspended cigarette smoke extract (CSE. Following incubation of muscle cells with gingival cell conditioned medium, muscle cell mitochondrial respiration and insulin signaling and action were determined as an indication of overall muscle metabolic health. Skeletal muscle cells incubated with conditioned medium of CSE-treated gingival cells had a profound reduction in mitochondrial respiration and respiratory control. Furthermore, skeletal muscle cells had a greatly reduced response in insulin-stimulated Akt phosphorylation and glycogen synthesis. Altogether, these results provide a novel perspective on the mechanism whereby cigarette smoke affects systemic metabolic function. In conclusion, we found that oral gingival cells treated with CSE create an altered milieu that is sufficient to both disrupted skeletal muscle cell mitochondrial function and insulin sensitivity.

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...

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.

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

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

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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.

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.

The role of satellite cells in muscle hypertrophy.

Science.gov (United States)

Blaauw, Bert; Reggiani, Carlo

2014-02-01

The role of satellite cells in muscle hypertrophy has long been a debated issue. In the late 1980s it was shown that proteins remain close to the myonucleus responsible for its synthesis, giving rise to the idea of a nuclear domain. This, together with the observation that during various models of muscle hypertrophy there is an activation of the muscle stem cells, i.e. satellite cells, lead to the idea that satellite cell activation is required for muscle hypertrophy. Thus, satellite cells are not only responsible for muscle repair and regeneration, but also for hypertrophic growth. Further support for this line of thinking was obtained after studies showing that irradiation of skeletal muscle, and therefore elimination of all satellite cells, completely prevented overload-induced hypertrophy. Recently however, using different transgenic approaches, it has become clear that muscle hypertrophy can occur without a contribution of satellite cells, even though in most situations of muscle hypertrophy satellite cells are activated. In this review we will discuss the contribution of satellite cells, and other muscle-resident stem cells, to muscle hypertrophy both in mice as well as in humans.

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

Institute of Scientific and Technical Information of China (English)

无

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.

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.

Muscle Stem Cells: A Model System for Adult Stem Cell Biology.

Science.gov (United States)

Cornelison, Ddw; Perdiguero, Eusebio

2017-01-01

Skeletal muscle stem cells, originally termed satellite cells for their position adjacent to differentiated muscle fibers, are absolutely required for the process of skeletal muscle repair and regeneration. In the last decade, satellite cells have become one of the most studied adult stem cell systems and have emerged as a standard model not only in the field of stem cell-driven tissue regeneration but also in stem cell dysfunction and aging. Here, we provide background in the field and discuss recent advances in our understanding of muscle stem cell function and dysfunction, particularly in the case of aging, and the potential involvement of muscle stem cells in genetic diseases such as the muscular dystrophies.

Phenotypic modulation of smooth muscle cells during formation of neointimal thickenings following vascular injury.

Science.gov (United States)

Thyberg, J

1998-07-01

Smooth muscle cells build up the media of mammalian arteries and constitute one of the principal cell types in atherosclerotic and restenotic lesions. Accordingly, they show a high degree of plasticity and are able to shift from a differentiated, contractile phenotype to a less differentiated, synthetic phenotype, and then back again. This modulation occurs as a response to vascular injury and includes a prominent structural reorganization with loss of myofilaments and formation of an extensive endoplasmic reticulum and a large Golgi complex. At the same time, the expression of cytoskeletal proteins and other gene products is altered. As a result, the cells lose their contractility and become able to migrate from the media to the intima, proliferate, and secrete extracellular matrix components, thereby contributing to the formation of intimal thickenings. The mechanisms behind this change in morphology and function of the smooth muscle cells are still incompletely understood. A crucial role has been ascribed to basement membrane proteins such as laminin and collagen type IV and adhesive proteins such as fibronectin. A significant role is also played by mitogenic proteins such as platelet-derived growth factor (PDGF) and basic fibroblast growth factor (bFGF). An improved knowledge of the regulation of smooth muscle differentiated properties represents an important part in the search for new methods of prevention and treatment of vascular disease.

Bacterial Adhesion & Blocking Bacterial Adhesion

DEFF Research Database (Denmark)

Vejborg, Rebecca Munk

2008-01-01

, which influence the transition from a planktonic lifestyle to a sessile lifestyle, have been studied. Protein conditioning film formation was found to influence bacterial adhesion and subsequent biofilm formation considerable, and an aqueous extract of fish muscle tissue was shown to significantly...... tract to the microbial flocs in waste water treatment facilities. Microbial biofilms may however also cause a wide range of industrial and medical problems, and have been implicated in a wide range of persistent infectious diseases, including implantassociated microbial infections. Bacterial adhesion...... is the first committing step in biofilm formation, and has therefore been intensely scrutinized. Much however, still remains elusive. Bacterial adhesion is a highly complex process, which is influenced by a variety of factors. In this thesis, a range of physico-chemical, molecular and environmental parameters...

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.)

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

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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.

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.

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

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

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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.

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.

Catechins activate muscle stem cells by Myf5 induction and stimulate muscle regeneration.

Science.gov (United States)

Kim, A Rum; Kim, Kyung Min; Byun, Mi Ran; Hwang, Jun-Ha; Park, Jung Il; Oh, Ho Taek; Kim, Hyo Kyeong; Jeong, Mi Gyeong; Hwang, Eun Sook; Hong, Jeong-Ho

2017-07-22

Muscle weakness is one of the most common symptoms in aged individuals and increases risk of mortality. Thus, maintenance of muscle mass is important for inhibiting aging. In this study, we investigated the effect of catechins, polyphenol compounds in green tea, on muscle regeneration. We found that (-)-epicatechin gallate (ECG) and (-)-epigallocatechin-3-gallate (EGCG) activate satellite cells by induction of Myf5 transcription factors. For satellite cell activation, Akt kinase was significantly induced after ECG treatment and ECG-induced satellite cell activation was blocked in the presence of Akt inhibitor. ECG also promotes myogenic differentiation through the induction of myogenic markers, including Myogenin and Muscle creatine kinase (MCK), in satellite and C2C12 myoblast cells. Finally, EGCG administration to mice significantly increased muscle fiber size for regeneration. Taken together, the results suggest that catechins stimulate muscle stem cell activation and differentiation for muscle regeneration. Copyright © 2017 Elsevier Inc. All rights reserved.

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.

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...

Functional heterogeneity of side population cells in skeletal muscle

International Nuclear Information System (INIS)

Uezumi, Akiyoshi; Ojima, Koichi; Fukada, So-ichiro; Ikemoto, Madoka; Masuda, Satoru; Miyagoe-Suzuki, Yuko; Takeda, Shin'ichi

2006-01-01

Skeletal muscle regeneration has been exclusively attributed to myogenic precursors, satellite cells. A stem cell-rich fraction referred to as side population (SP) cells also resides in skeletal muscle, but its roles in muscle regeneration remain unclear. We found that muscle SP cells could be subdivided into three sub-fractions using CD31 and CD45 markers. The majority of SP cells in normal non-regenerating muscle expressed CD31 and had endothelial characteristics. However, CD31 - CD45 - SP cells, which are a minor subpopulation in normal muscle, actively proliferated upon muscle injury and expressed not only several regulatory genes for muscle regeneration but also some mesenchymal lineage markers. CD31 - CD45 - SP cells showed the greatest myogenic potential among three SP sub-fractions, but indeed revealed mesenchymal potentials in vitro. These SP cells preferentially differentiated into myofibers after intramuscular transplantation in vivo. Our results revealed the heterogeneity of muscle SP cells and suggest that CD31 - CD45 - SP cells participate in muscle regeneration

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

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.

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....

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

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)

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.

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.

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

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

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.

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.

iTRAQ quantitative proteomics-based identification of cell adhesion as a dominant phenotypic modulation in thrombin-stimulated human aortic endothelial cells.

Science.gov (United States)

Wang, Huang-Joe; Chen, Sung-Fang; Lo, Wan-Yu

2015-05-01

The phenotypic changes in thrombin-stimulated endothelial cells include alterations in permeability, cell shape, vasomotor tone, leukocyte trafficking, migration, proliferation, and angiogenesis. Previous studies regarding the pleotropic effects of thrombin on the endothelium used human umbilical vein endothelial cells (HUVECs)-cells derived from fetal tissue that does not exist in adults. Only a few groups have used screening approaches such as microarrays to profile the global effects of thrombin on endothelial cells. Moreover, the proteomic changes of thrombin-stimulated human aortic endothelial cells (HAECs) have not been elucidated. HAECs were stimulated with 2 units/mL thrombin for 5h and their proteome was investigated using isobaric tags for the relative and absolute quantification (iTRAQ) and the MetaCore(TM) software. A total of 627 (experiment A) and 622 proteins (experiment B) were quantified in the duplicated iTRAQ analyses. MetaCore(TM) pathway analysis identified cell adhesion as a dominant phenotype in thrombin-stimulated HAECs. Replicated iTRAQ data revealed that "Cell adhesion_Chemokines and adhesion," "Cell adhesion_Histamine H1 receptor signaling in the interruption of cell barrier integrity," and "Cell adhesion_Integrin-mediated cell adhesion and migration" were among the top 10 statistically significant pathways. The cell adhesion phenotype was verified by increased THP-1 adhesion to thrombin-stimulated HAECs. In addition, the expression of ICAM-1, VCAM-1, and SELE was significantly upregulated in thrombin-stimulated HAECs. Several regulatory pathways are altered in thrombin-stimulated HAECs, with cell adhesion being the dominant altered phenotype. Our findings show the feasibility of the iTRAQ technique for evaluating cellular responses to acute stimulation. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

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.

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

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.

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)

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.

Heparan sulfate chain valency controls syndecan-4 function in cell adhesion

DEFF Research Database (Denmark)

Gopal, Sandeep; Bober, Adam; Whiteford, James R

2010-01-01

, clustering of one-chain syndecan-4 forms with antibodies overcame the block, indicating that valency of interactions with ligands is a key component of syndecan-4 function. Measurements of focal contact/adhesion size and focal adhesion kinase phosphorylation correlated with syndecan-4 status and alpha...... of the core protein cytoplasmic domain, though not interactions with PDZ proteins. A second key requirement is multiple heparan sulfate chains. Mutant syndecan-4 with no chains, or only one chain, failed to restore the wild type phenotype, while those expressing two or three were competent. However......-smooth muscle actin organization, being reduced where syndecan-4 function was compromised by a lack of multiple heparan sulfate chains....

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.

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.

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

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.

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.

In vitro evaluation of tissue adhesives composed of hydrophobically modified gelatins and disuccinimidyl tartrate

Directory of Open Access Journals (Sweden)

Miyuki Matsuda

2012-01-01

Full Text Available The effect of the hydrophobic group content in gelatin on the bonding strength of novel tissue–penetrating tissue adhesives was evaluated. The hydrophobic groups introduced into gelatin were the saturated hexanoyl, palmitoyl, and stearoyl groups, and the unsaturated oleoyl group. A collagen casing was employed as an adherend to model soft tissue for the in vitro determination of bonding strength of tissue adhesives composed of various hydrophobically modified gelatins and disuccinimidyl tartrate. The adhesive composed of stearoyl-modified gelatin (7.4% stearoyl; 10Ste and disuccinimidyl tartrate showed the highest bonding strength. The bonding strength of the adhesives decreased as the degree of substitution of the hydrophobic groups increased. Cell culture experiments demonstrated that fluorescein isothiocyanate-labeled 10Ste was integrated onto the surface of smooth muscle cells and showed no cytotoxicity. These results suggest that 10Ste interacted with the hydrophobic domains of collagen casings, such as hydrophobic amino acid residues and cell membranes. Therefore, 10Ste–disuccinimidyl tartrate is a promising adhesive for use in aortic dissection.

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.

Heterogeneity among muscle precursor cells in adult skeletal muscles with differing regenerative capacities.

Science.gov (United States)

Pavlath, G K; Thaloor, D; Rando, T A; Cheong, M; English, A W; Zheng, B

1998-08-01

Skeletal muscle has a remarkable capacity to regenerate after injury, although studies of muscle regeneration have heretofore been limited almost exclusively to limb musculature. Muscle precursor cells in skeletal muscle are responsible for the repair of damaged muscle. Heterogeneity exists in the growth and differentiation properties of muscle precursor cell (myoblast) populations throughout limb development but whether the muscle precursor cells differ among adult skeletal muscles is unknown. Such heterogeneity among myoblasts in the adult may give rise to skeletal muscles with different regenerative capacities. Here we compare the regenerative response of a masticatory muscle, the masseter, to that of limb muscles. After exogenous trauma (freeze or crush injuries), masseter muscle regenerated much less effectively than limb muscle. In limb muscle, normal architecture was restored 12 days after injury, whereas in masseter muscle, minimal regeneration occurred during the same time period. Indeed, at late time points, masseter muscles exhibited increased fibrous connective tissue in the region of damage, evidence of ineffective muscle regeneration. Similarly, in response to endogenous muscle injury due to a muscular dystrophy, widespread evidence of impaired regeneration was present in masseter muscle but not in limb muscle. To explore the cellular basis of these different regenerative capacities, we analyzed the myoblast populations of limb and masseter muscles both in vivo and in vitro. From in vivo analyses, the number of myoblasts in regenerating muscle was less in masseter compared with limb muscle. Assessment of population growth in vitro indicated that masseter myoblasts grow more slowly than limb myoblasts under identical conditions. We conclude that the impaired regeneration in masseter muscles is due to differences in the intrinsic myoblast populations compared to limb muscles.

Pervasive satellite cell contribution to uninjured adult muscle fibers.

Science.gov (United States)

Pawlikowski, Bradley; Pulliam, Crystal; Betta, Nicole Dalla; Kardon, Gabrielle; Olwin, Bradley B

2015-01-01

Adult skeletal muscle adapts to functional needs, maintaining consistent numbers of myonuclei and stem cells. Although resident muscle stem cells or satellite cells are required for muscle growth and repair, in uninjured muscle, these cells appear quiescent and metabolically inactive. To investigate the satellite cell contribution to myofibers in adult uninjured skeletal muscle, we labeled satellite cells by inducing a recombination of LSL-tdTomato in Pax7(CreER) mice and scoring tdTomato+ myofibers as an indicator of satellite cell fusion. Satellite cell fusion into myofibers plateaus postnatally between 8 and 12 weeks of age, reaching a steady state in hindlimb muscles, but in extra ocular or diaphragm muscles, satellite cell fusion is maintained at postnatal levels irrespective of the age assayed. Upon recombination and following a 2-week chase in 6-month-old mice, tdTomato-labeled satellite cells fused into myofibers as 20, 50, and 80 % of hindlimb, extra ocular, and diaphragm myofibers, respectively, were tdTomato+. Satellite cells contribute to uninjured myofibers either following a cell division or directly without an intervening cell division. The frequency of satellite cell fusion into the skeletal muscle fibers is greater than previously estimated, suggesting an important functional role for satellite cell fusion into adult myofibers and a requirement for active maintenance of satellite cell numbers in uninjured skeletal muscle.

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

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

Study of muscle cell dedifferentiation after skeletal muscle injury of mice with a Cre-Lox system.

Science.gov (United States)

Mu, Xiaodong; Peng, Hairong; Pan, Haiying; Huard, Johnny; Li, Yong

2011-02-03

Dedifferentiation of muscle cells in the tissue of mammals has yet to be observed. One of the challenges facing the study of skeletal muscle cell dedifferentiation is the availability of a reliable model that can confidentially distinguish differentiated cell populations of myotubes and non-fused mononuclear cells, including stem cells that can coexist within the population of cells being studied. In the current study, we created a Cre/Lox-β-galactosidase system, which can specifically tag differentiated multinuclear myotubes and myotube-generated mononuclear cells based on the activation of the marker gene, β-galactosidase. By using this system in an adult mouse model, we found that β-galactosidase positive mononuclear cells were generated from β-galactosidase positive multinuclear myofibers upon muscle injury. We also demonstrated that these mononuclear cells can develop into a variety of different muscle cell lineages, i.e., myoblasts, satellite cells, and muscle derived stem cells. These novel findings demonstrated, for the first time, that cellular dedifferentiation of skeletal muscle cells actually occurs in mammalian skeletal muscle following traumatic injury in vivo.

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

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

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.

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.

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

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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.

Tissue-specific stem cells: Lessons from the skeletal muscle satellite cell

Science.gov (United States)

Brack, Andrew S.; Rando, Thomas A.

2012-01-01

In 1961, the satellite cell was first identified when electron microscopic examination of skeletal muscle demonstrated a cell wedged between the plasma membrane of the muscle fiber and the basement membrane. In recent years it has been conclusively demonstrated that the satellite cell is the primary cellular source for muscle regeneration and is equipped with the potential to self renew, thus functioning as a bone fide skeletal muscle stem cell (MuSC). As we move past the 50th anniversary of the satellite cell, we take this opportunity to discuss the current state of the art and dissect the unknowns in the MuSC field. PMID:22560074

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.

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

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.

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

Quercetin inhibits adipogenesis of muscle progenitor cells in vitro

Directory of Open Access Journals (Sweden)

Tomoko Funakoshi

2018-03-01

Full Text Available Muscle satellite cells are committed myogenic progenitors capable of contributing to myogenesis to maintain adult muscle mass and function. Several experiments have demonstrated that muscle satellite cells can differentiate into adipocytes in vitro, supporting the mesenchymal differentiation potential of these cells. Moreover, muscle satellite cells may be a source of ectopic muscle adipocytes, explaining the lipid accumulation often observed in aged skeletal muscle (sarcopenia and in muscles of patients` with diabetes. Quercetin, a polyphenol, is one of the most abundant flavonoids distributed in edible plants, such as onions and apples, and possesses antioxidant, anticancer, and anti-inflammatory properties. In this study, we examined whether quercetin inhibited the adipogenesis of muscle satellite cells in vitro with primary cells from rat limbs by culture in the presence of quercetin under adipogenic conditions. Morphological observations, Oil Red-O staining results, triglyceride content analysis, and quantitative reverse transcription polymerase chain reaction revealed that quercetin was capable of inhibiting the adipogenic induction of muscle satellite cells into adipocytes in a dose-dependent manner by suppressing the transcript levels of adipogenic markers, such as peroxisome proliferator-activated receptor-γ and fatty acid binding protein 4. Our results suggested that quercetin inhibited the adipogenesis of muscle satellite cells in vitro by suppressing the transcription of adipogenic markers. Keywords: Quercetin, Muscle satellite cell, Differentiation, Intramuscular lipid

[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.

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.

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.

Engineered matrices for skeletal muscle satellite cell engraftment and function.

Science.gov (United States)

Han, Woojin M; Jang, Young C; García, Andrés J

2017-07-01

Regeneration of traumatically injured skeletal muscles is severely limited. Moreover, the regenerative capacity of skeletal muscle declines with aging, further exacerbating the problem. Recent evidence supports that delivery of muscle satellite cells to the injured muscles enhances muscle regeneration and reverses features of aging, including reduction in muscle mass and regenerative capacity. However, direct delivery of satellite cells presents a challenge at a translational level due to inflammation and donor cell death, motivating the need to develop engineered matrices for muscle satellite cell delivery. This review will highlight important aspects of satellite cell and their niche biology in the context of muscle regeneration, and examine recent progresses in the development of engineered cell delivery matrices designed for skeletal muscle regeneration. Understanding the interactions of muscle satellite cells and their niche in both native and engineered systems is crucial to developing muscle pathology-specific cell- and biomaterial-based therapies. Copyright © 2016 International Society of Matrix Biology. Published by Elsevier B.V. All rights reserved.

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)

Gentiana lutea exerts anti-atherosclerotic effects by preventing endothelial inflammation and smooth muscle cell migration.

Science.gov (United States)

Kesavan, R; Chandel, S; Upadhyay, S; Bendre, R; Ganugula, R; Potunuru, U R; Giri, H; Sahu, G; Kumar, P Uday; Reddy, G Bhanuprakash; Joksic, G; Bera, A K; Dixit, Madhulika

2016-04-01

Studies suggest that Gentiana lutea (GL), and its component isovitexin, may exhibit anti-atherosclerotic properties. In this study we sought to investigate the protective mechanism of GL aqueous root extract and isovitexin on endothelial inflammation, smooth muscle cell migation, and on the onset and progression of atherosclerosis in streptozotocin (STZ)-induced diabetic rats. Our results show that both GL extract and isovitexin, block leukocyte adhesion and generation of reactive oxygen species in human umbilical vein endothelial cells (HUVECs) and rat aortic smooth muscle cells (RASMCs), following TNF-alpha and platelet derived growth factor-BB (PDGF-BB) challenges respectively. Both the extract and isovitexin blocked TNF-α induced expression of ICAM-1 and VCAM-1 in HUVECs. PDGF-BB induced migration of RASMCs and phospholipase C-γ activation, were also abrogated by GL extract and isovitexin. Fura-2 based ratiometric measurements demonstrated that, both the extact, and isovitexin, inhibit PDGF-BB mediated intracellular calcium rise in RASMCs. Supplementation of regular diet with 2% GL root powder for STZ rats, reduced total cholesterol in blood. Oil Red O staining demonstrated decreased lipid accumulation in aortic wall of diabetic animals upon treatment with GL. Medial thickness and deposition of collagen in the aortic segment of diabetic rats were also reduced upon supplementation. Immunohistochemistry demonstrated reduced expression of vascular cell adhesion molecule-1 (VCAM-1), inducible nitric oxide synthase (iNOS), and vascular endothelial cadherin (VE-cadherin) in aortic segments of diabetic rats following GL treatment. Thus, our results support that GL root extract/powder and isovitexin exhibit anti-atherosclerotic activities. Copyright © 2016 The Italian Society of Diabetology, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition, and the Department of Clinical Medicine and Surgery, Federico II University

Brain and muscle Arnt-like 1 promotes skeletal muscle regeneration through satellite cell expansion

Energy Technology Data Exchange (ETDEWEB)

Chatterjee, Somik [Center for Diabetes Research, Department of Medicine, Houston Methodist Research Institute, Houston, TX 77030 (United States); Yin, Hongshan [Center for Diabetes Research, Department of Medicine, Houston Methodist Research Institute, Houston, TX 77030 (United States); Department of Cardiovascular Medicine, Third Affiliated Hospital, Hebei Medical University, Shijiazhuang 050051, Hebei (China); Nam, Deokhwa [Center for Diabetes Research, Department of Medicine, Houston Methodist Research Institute, Houston, TX 77030 (United States); Li, Yong [Department of Pediatric Surgery, Center for Stem Cell Research and Regenerative Medicine, University of Texas Health Science Center at Houston, Houston, TX 77030 (United States); Ma, Ke, E-mail: kma@houstonmethodist.org [Center for Diabetes Research, Department of Medicine, Houston Methodist Research Institute, Houston, TX 77030 (United States)

2015-02-01

Circadian clock is an evolutionarily conserved timing mechanism governing diverse biological processes and the skeletal muscle possesses intrinsic functional clocks. Interestingly, although the essential clock transcription activator, Brain and muscle Arnt-like 1 (Bmal1), participates in maintenance of muscle mass, little is known regarding its role in muscle growth and repair. In this report, we investigate the in vivo function of Bmal1 in skeletal muscle regeneration using two muscle injury models. Bmal1 is highly up-regulated by cardiotoxin injury, and its genetic ablation significantly impairs regeneration with markedly suppressed new myofiber formation and attenuated myogenic induction. A similarly defective regenerative response is observed in Bmal1-null mice as compared to wild-type controls upon freeze injury. Lack of satellite cell expansion accounts for the regeneration defect, as Bmal1{sup −/−} mice display significantly lower satellite cell number with nearly abolished induction of the satellite cell marker, Pax7. Furthermore, satellite cell-derived primary myoblasts devoid of Bmal1 display reduced growth and proliferation ex vivo. Collectively, our results demonstrate, for the first time, that Bmal1 is an integral component of the pro-myogenic response that is required for muscle repair. This mechanism may underlie its role in preserving adult muscle mass and could be targeted therapeutically to prevent muscle-wasting diseases. - Highlights: • Bmal1 is highly inducible by muscle injury and myogenic stimuli. • Genetic ablation of Bmal1 significantly impairs muscle regeneration. • Bmal1 promotes satellite cell expansion during muscle regeneration. • Bmal1-deficient primary myoblasts display attenuated growth and proliferation.

Brain and muscle Arnt-like 1 promotes skeletal muscle regeneration through satellite cell expansion

International Nuclear Information System (INIS)

Chatterjee, Somik; Yin, Hongshan; Nam, Deokhwa; Li, Yong; Ma, Ke

2015-01-01

Circadian clock is an evolutionarily conserved timing mechanism governing diverse biological processes and the skeletal muscle possesses intrinsic functional clocks. Interestingly, although the essential clock transcription activator, Brain and muscle Arnt-like 1 (Bmal1), participates in maintenance of muscle mass, little is known regarding its role in muscle growth and repair. In this report, we investigate the in vivo function of Bmal1 in skeletal muscle regeneration using two muscle injury models. Bmal1 is highly up-regulated by cardiotoxin injury, and its genetic ablation significantly impairs regeneration with markedly suppressed new myofiber formation and attenuated myogenic induction. A similarly defective regenerative response is observed in Bmal1-null mice as compared to wild-type controls upon freeze injury. Lack of satellite cell expansion accounts for the regeneration defect, as Bmal1 −/− mice display significantly lower satellite cell number with nearly abolished induction of the satellite cell marker, Pax7. Furthermore, satellite cell-derived primary myoblasts devoid of Bmal1 display reduced growth and proliferation ex vivo. Collectively, our results demonstrate, for the first time, that Bmal1 is an integral component of the pro-myogenic response that is required for muscle repair. This mechanism may underlie its role in preserving adult muscle mass and could be targeted therapeutically to prevent muscle-wasting diseases. - Highlights: • Bmal1 is highly inducible by muscle injury and myogenic stimuli. • Genetic ablation of Bmal1 significantly impairs muscle regeneration. • Bmal1 promotes satellite cell expansion during muscle regeneration. • Bmal1-deficient primary myoblasts display attenuated growth and proliferation

Adenosine formation in contracting primary rat skeletal muscle cells and endothelial cells in culture

DEFF Research Database (Denmark)

Hellsten, Ylva; Frandsen, Ulrik

1997-01-01

1. The present study examined the capacity for adenosine formation, uptake and metabolism in contracting primary rat muscle cells and in microvascular endothelial cells in culture. 2. Strong and moderate electrical simulation of skeletal muscle cells led to a significantly greater increase....... 3. Addition of microvascular endothelial cells to the cultured skeletal muscle cells enhanced the contraction-induced accumulation of extracellular adenosine (P Skeletal muscle cells were...... in the extracellular adenosine concentration (421 +/- 91 and 235 +/- 30 nmol (g protein)-1, respectively; P muscle cells (161 +/- 20 nmol (g protein)-1). The ATP concentration was lower (18%; P contracted, but not in the moderately contracted muscle cells...

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.

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.

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...

Hamster thecal cells express muscle characteristics

International Nuclear Information System (INIS)

Self, D.A.; Schroeder, P.C.; Gown, A.M.

1988-01-01

Contraction of the follicular wall about the time of ovulation appears to be a coordinated event; however, the cells that mediate it remain poorly studied. We examined the theca externa cells in the wall of hamster follicles for the presence of a functional actomyosin system, both in developing follicles and in culture. We used a monoclonal antibody (HHF35) that recognizes the alpha and gamma isoelectric variants of actin normally found in muscle, but not the beta variant associated with non-muscle sources, to evaluate large preovulatory follicles for actin content and composition. Antibody staining of sectioned ovaries showed intense circumferential reactivity in the outermost wall of developing follicles. Immunoblots from two-dimensional gels of theca externa lysates demonstrated the presence of the two muscle-specific isozymes of actin. Immunofluorescence of cultured follicular cells pulse-labeled with [3H] thymidine (for autoradiographic detection of DNA replication) revealed the presence, in many dividing cells, of actin filaments aligned primarily along the longitudinal axis of the cells. In cultures exposed to the calcium ionophore A23187 (10(-4) M) for varying periods (5 min to 1 h), contraction of many individual muscle-actin-positive cells was observed. Immunofluorescence of these cells, fixed immediately after ionophore-induced contraction, revealed compaction of the actin filaments. Our findings demonstrate that the cells of the theca externa contain muscle actins from an early stage and that these cells are capable of contraction even while proliferating in subconfluent cultures. They suggest that follicular growth may include a naturally occurring developmental sequence in which a contractile cell type proliferates in the differentiated state

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

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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

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.)

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

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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.

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

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.

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.

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

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

Muscle-derived stem cells isolated as non-adherent population give rise to cardiac, skeletal muscle and neural lineages

International Nuclear Information System (INIS)

Arsic, Nikola; Mamaeva, Daria; Lamb, Ned J.; Fernandez, Anne

2008-01-01

Stem cells with the ability to differentiate in specialized cell types can be extracted from a wide array of adult tissues including skeletal muscle. Here we have analyzed a population of cells isolated from skeletal muscle on the basis of their poor adherence on uncoated or collagen-coated dishes that show multi-lineage differentiation in vitro. When analysed under proliferative conditions, these cells express stem cell surface markers Sca-1 (65%) and Bcrp-1 (80%) but also MyoD (15%), Neuronal β III-tubulin (25%), GFAP (30%) or Nkx2.5 (1%). Although capable of growing as non-attached spheres for months, when given an appropriate matrix, these cells adhere giving rise to skeletal muscle, neuronal and cardiac muscle cell lineages. A similar cell population could not be isolated from either bone marrow or cardiac tissue suggesting their specificity to skeletal muscle. When injected into damaged muscle, these non-adherent muscle-derived cells are retrieved expressing Pax7, in a sublaminar position characterizing satellite cells and participate in forming new myofibers. These data show that a non-adherent stem cell population can be specifically isolated and expanded from skeletal muscle and upon attachment to a matrix spontaneously differentiate into muscle, cardiac and neuronal lineages in vitro. Although competing with resident satellite cells, these cells are shown to significantly contribute to repair of injured muscle in vivo supporting that a similar muscle-derived non-adherent cell population from human muscle may be useful in treatment of neuromuscular disorders

Muscle-derived stem cells isolated as non-adherent population give rise to cardiac, skeletal muscle and neural lineages.

Science.gov (United States)

Arsic, Nikola; Mamaeva, Daria; Lamb, Ned J; Fernandez, Anne

2008-04-01

Stem cells with the ability to differentiate in specialized cell types can be extracted from a wide array of adult tissues including skeletal muscle. Here we have analyzed a population of cells isolated from skeletal muscle on the basis of their poor adherence on uncoated or collagen-coated dishes that show multi-lineage differentiation in vitro. When analysed under proliferative conditions, these cells express stem cell surface markers Sca-1 (65%) and Bcrp-1 (80%) but also MyoD (15%), Neuronal beta III-tubulin (25%), GFAP (30%) or Nkx2.5 (1%). Although capable of growing as non-attached spheres for months, when given an appropriate matrix, these cells adhere giving rise to skeletal muscle, neuronal and cardiac muscle cell lineages. A similar cell population could not be isolated from either bone marrow or cardiac tissue suggesting their specificity to skeletal muscle. When injected into damaged muscle, these non-adherent muscle-derived cells are retrieved expressing Pax7, in a sublaminar position characterizing satellite cells and participate in forming new myofibers. These data show that a non-adherent stem cell population can be specifically isolated and expanded from skeletal muscle and upon attachment to a matrix spontaneously differentiate into muscle, cardiac and neuronal lineages in vitro. Although competing with resident satellite cells, these cells are shown to significantly contribute to repair of injured muscle in vivo supporting that a similar muscle-derived non-adherent cell population from human muscle may be useful in treatment of neuromuscular disorders.

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

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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.

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

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

Effective fiber hypertrophy in satellite cell-depleted skeletal muscle

Science.gov (United States)

McCarthy, John J.; Mula, Jyothi; Miyazaki, Mitsunori; Erfani, Rod; Garrison, Kelcye; Farooqui, Amreen B.; Srikuea, Ratchakrit; Lawson, Benjamin A.; Grimes, Barry; Keller, Charles; Van Zant, Gary; Campbell, Kenneth S.; Esser, Karyn A.; Dupont-Versteegden, Esther E.; Peterson, Charlotte A.

2011-01-01

An important unresolved question in skeletal muscle plasticity is whether satellite cells are necessary for muscle fiber hypertrophy. To address this issue, a novel mouse strain (Pax7-DTA) was created which enabled the conditional ablation of >90% of satellite cells in mature skeletal muscle following tamoxifen administration. To test the hypothesis that satellite cells are necessary for skeletal muscle hypertrophy, the plantaris muscle of adult Pax7-DTA mice was subjected to mechanical overload by surgical removal of the synergist muscle. Following two weeks of overload, satellite cell-depleted muscle showed the same increases in muscle mass (approximately twofold) and fiber cross-sectional area with hypertrophy as observed in the vehicle-treated group. The typical increase in myonuclei with hypertrophy was absent in satellite cell-depleted fibers, resulting in expansion of the myonuclear domain. Consistent with lack of nuclear addition to enlarged fibers, long-term BrdU labeling showed a significant reduction in the number of BrdU-positive myonuclei in satellite cell-depleted muscle compared with vehicle-treated muscle. Single fiber functional analyses showed no difference in specific force, Ca2+ sensitivity, rate of cross-bridge cycling and cooperativity between hypertrophied fibers from vehicle and tamoxifen-treated groups. Although a small component of the hypertrophic response, both fiber hyperplasia and regeneration were significantly blunted following satellite cell depletion, indicating a distinct requirement for satellite cells during these processes. These results provide convincing evidence that skeletal muscle fibers are capable of mounting a robust hypertrophic response to mechanical overload that is not dependent on satellite cells. PMID:21828094

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.

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

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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.

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

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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

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

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.

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.

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.

PINCH1 regulates cell-matrix and cell-cell adhesions, cell polarity and cell survival during the peri-implantation stage

DEFF Research Database (Denmark)

Li, Shaohua; Bordoy, Randi; Stanchi, Fabio

2005-01-01

PINCH1 is composed of 5 LIM domains, binds integrin-linked kinase (ILK) and locates to integrin-mediated adhesion sites. In order to investigate PINCH1 function we generated mice and embryonic stem (ES) cell-derived embryoid bodies (EBs) lacking the PINCH1 gene. Similar to mice lacking beta1...... integrin or Ilk, loss of PINCH1 arrested development at the peri-implantation stage. In contrast to beta1 integrin or Ilk mutants, however, disruption of the PINCH1 gene produced implantation chambers with visible cell clumps even at embryonic day 9.5. In order to define the phenotype leading to the peri...... not observed in beta1 integrin- or ILK-deficient mice or EBs, included abnormal cell-cell adhesion of endoderm and epiblast as well as the presence of apoptotic cells in the endodermal cell layer. Although ILK and PINCH1 were shown to be involved in the phosphorylation of serine-473 of PKB/Akt, immunostaining...

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...

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.

TRIM15 is a focal adhesion protein that regulates focal adhesion disassembly

Science.gov (United States)

Uchil, Pradeep D.; Pawliczek, Tobias; Reynolds, Tracy D.; Ding, Siyuan; Hinz, Angelika; Munro, James B.; Huang, Fang; Floyd, Robert W.; Yang, Haitao; Hamilton, William L.; Bewersdorf, Joerg; Xiong, Yong; Calderwood, David A.; Mothes, Walther

2014-01-01

ABSTRACT Focal adhesions are macromolecular complexes that connect the actin cytoskeleton to the extracellular matrix. Dynamic turnover of focal adhesions is crucial for cell migration. Paxillin is a multi-adaptor protein that plays an important role in regulating focal adhesion dynamics. Here, we identify TRIM15, a member of the tripartite motif protein family, as a paxillin-interacting factor and a component of focal adhesions. TRIM15 localizes to focal contacts in a myosin-II-independent manner by an interaction between its coiled-coil domain and the LD2 motif of paxillin. Unlike other focal adhesion proteins, TRIM15 is a stable focal adhesion component with restricted mobility due to its ability to form oligomers. TRIM15-depleted cells display impaired cell migration and reduced focal adhesion disassembly rates, in addition to enlarged focal adhesions. Thus, our studies demonstrate a cellular function for TRIM15 as a regulatory component of focal adhesion turnover and cell migration. PMID:25015296

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

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.

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...

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

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.

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

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.

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.

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...

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