Sample records for adhesion protein n-cadherin

  1. N-cadherin-mediated cell-cell adhesion promotes cell migration in a three-dimensional matrix.

    PubMed

    Shih, Wenting; Yamada, Soichiro

    2012-08-01

    Cancer cells that originate from epithelial tissues typically lose epithelial specific cell-cell junctions, but these transformed cells are not devoid of cell-cell adhesion proteins. Using hepatocyte-growth-factor-treated MDCK cells that underwent a complete epithelial-to-mesenchymal transition, we analyzed cell-cell adhesion between these highly invasive transformed epithelial cells in a three-dimensional (3D) collagen matrix. In a 3D matrix, these transformed cells formed elongated multicellular chains, and migrated faster and more persistently than single cells in isolation. In addition, the cell clusters were enriched with stress-fiber-like actin bundles that provided contractile forces. N-cadherin-knockdown cells failed to form cell-cell junctions or migrate, and the expression of the N-cadherin cytoplasmic or extracellular domain partially rescued the knockdown phenotype. By contrast, the expression of N-cadherin-?-catenin chimera rescued the knockdown phenotype, but individual cells within the cell clusters were less mobile. Together, our findings suggest that a dynamic N-cadherin and actin linkage is required for efficient 3D collective migration. PMID:22467866

  2. Neural (N-) cadherin, a synaptic adhesion molecule, is induced in hippocampal mossy fiber axonal sprouts by seizure.

    PubMed

    Shan, Weisong; Yoshida, Mika; Wu, Xi-Ru; Huntley, George W; Colman, David R

    2002-08-01

    Aberrant mossy fiber sprouting and synaptic reorganization are plastic responses in human temporal lobe epilepsy, and in pilocarpine-induced epilepsy in rodents. Although the morphological features of the hippocampal epileptic reaction have been well documented, the molecular mechanisms underlying these structural changes are not understood. The classic cadherins, calcium-dependent cell adhesion molecules, are known to function in development in neurite outgrowth, synapse formation, and stabilization. In pilocarpine-induced status epilepticus, the expression of N-cadherin mRNA was sharply upregulated and reached a maximum level (1- to 2.5-fold) at 1- to 4 weeks postseizure in the granule cell layer and the pyramidal cell layer of CA3. N-cadherin protein was correspondingly increased and became concentrated in the inner molecular layer of the dentate gyrus, consistent with the position of mossy fiber axonal sprouts. Moreover, N-cadherin labeling was punctate; colocalized with definitive synaptic markers, and partially localized on polysialated forms of neural cell adhesion molecule (PSA-NCAM)-positive dendrites of granule cells in the inner molecular layer. Our findings show that N-cadherin is likely to be a key factor in responsive synaptogenesis following status epilepticus, where it functions as a mediator of de novo synapse formation. PMID:12125071

  3. Mechanical coupling between transsynaptic N-cadherin adhesions and actin flow stabilizes dendritic spines

    PubMed Central

    Chazeau, Anaël; Garcia, Mikael; Czöndör, Katalin; Perrais, David; Tessier, Béatrice; Giannone, Grégory; Thoumine, Olivier

    2015-01-01

    The morphology of neuronal dendritic spines is a critical indicator of synaptic function. It is regulated by several factors, including the intracellular actin/myosin cytoskeleton and transcellular N-cadherin adhesions. To examine the mechanical relationship between these molecular components, we performed quantitative live-imaging experiments in primary hippocampal neurons. We found that actin turnover and structural motility were lower in dendritic spines than in immature filopodia and increased upon expression of a nonadhesive N-cadherin mutant, resulting in an inverse relationship between spine motility and actin enrichment. Furthermore, the pharmacological stimulation of myosin II induced the rearward motion of actin structures in spines, showing that myosin II exerts tension on the actin network. Strikingly, the formation of stable, spine-like structures enriched in actin was induced at contacts between dendritic filopodia and N-cadherin–coated beads or micropatterns. Finally, computer simulations of actin dynamics mimicked various experimental conditions, pointing to the actin flow rate as an important parameter controlling actin enrichment in dendritic spines. Together these data demonstrate that a clutch-like mechanism between N-cadherin adhesions and the actin flow underlies the stabilization of dendritic filopodia into mature spines, a mechanism that may have important implications in synapse initiation, maturation, and plasticity in the developing brain. PMID:25568337

  4. A fusion protein N-cadherin-Fc as an artificial extracellular matrix surface for maintenance of stem cell features

    Microsoft Academic Search

    Xiao-Shan Yue; Yuta Murakami; Toshiyuki Tamai; Masato Nagaoka; Chong-Su Cho; Yoshihiro Ito; Toshihiro Akaike

    2010-01-01

    N-cadherin is a cell–cell adhesion molecule and plays important roles in neural development. With conventionally used extracellular matrices (ECMs), maintenance of undifferentiated state of stem cells and regulation of their neural differentiation process is very difficult due to the colony formation through intercellular interactions. To overcome the above-mentioned problems, we developed a new artificial ECM to mimic N-cadherin-mediated cell adhesion.

  5. FAK and paxillin: regulators of N-cadherin adhesion and inhibitors of cell migration?

    Microsoft Academic Search

    Michael D. Schaller

    2004-01-01

    FAK and paxillin are important components in integrin- regulated signaling. New evidence suggests that these two proteins function in crosstalk between cell-matrix and cell-cell adhesions. Further, new insight suggests that under some conditions these proteins inhibit cell migration, in contrast to their established roles in several cell systems as positive regulators of cell adhesion and migration. FAK and paxillin are

  6. Asymmetric N-Cadherin Expression Results in Synapse Dysfunction, Synapse Elimination, and Axon Retraction in Cultured Mouse Neurons

    PubMed Central

    Pielarski, Kim N.; van Stegen, Bernd; Andreyeva, Aksana; Nieweg, Katja; Jüngling, Kay; Redies, Christoph; Gottmann, Kurt

    2013-01-01

    Synapse elimination and pruning of axon collaterals are crucial developmental events in the refinement of neuronal circuits. While a control of synapse formation by adhesion molecules is well established, the involvement of adhesion molecules in developmental synapse loss is poorly characterized. To investigate the consequences of mis-match expression of a homophilic synaptic adhesion molecule, we analysed an asymmetric, exclusively postsynaptic expression of N-cadherin. This was induced by transfecting individual neurons in cultures of N-cadherin knockout mouse neurons with a N-cadherin expression vector. 2 days after transfection, patch-clamp analysis of AMPA receptor-mediated miniature postsynaptic currents revealed an impaired synaptic function without a reduction in the number of presynaptic vesicle clusters. Long-term asymmetric expression of N-cadherin for 8 days subsequently led to synapse elimination as indicated by a loss of colocalization of presynaptic vesicles and postsynaptic PSD95 protein. We further studied long-term asymmetric N-cadherin expression by conditional, Cre-induced knockout of N-cadherin in individual neurons in cultures of N-cadherin expressing cortical mouse neurons. This resulted in a strong retraction of axonal processes in individual neurons that lacked N-cadherin protein. Moreover, an in vivo asymmetric expression of N-cadherin in the developmentally transient cortico-tectal projection was indicated by in-situ hybridization with layer V neurons lacking N-cadherin expression. Thus, mis-match expression of N-cadherin might contribute to selective synaptic connectivity. PMID:23382872

  7. Expression of motility-related protein MRP1/CD9, N-cadherin, E-cadherin, alpha-catenin and beta-catenin in retinoblastoma.

    PubMed

    Mohan, Adithi; Nalini, Venkatesan; Mallikarjuna, Kandalam; Jyotirmay, Biswas; Krishnakumar, Subramanian

    2007-04-01

    In our earlier study we showed that invasive retinoblastoma (RB) had down regulated tetraspanin protein KAI1/CD82, a family of cell surface glycoprotein. KAI1 may link to the cell surface molecules, such as integrins, E-cadherin, and other TM4SF members, and loss of KAI1 function may have a significant role in the progression of retinoblastoma. We also showed that epithelial cell adhesion molecule (EpCAM) is overexpressed in invasive RB. EpCAM expression decreases adhesion mediated by cadherins. Thus, we were further interested in studying the role of other adhesion molecules like cadherins and catenins in RB. We studied the expression of Motility-Related Protein 1 (MRP-1)/CD9, E-cadherin, N-cadherin, alpha-catenin and beta-catenin in RB and correlated clinicopathologically in 62 archival paraffin-embedded tumors by immunohistochemistry. There were 29 tumors with no invasion of choroids/optic nerve and 33 tumors with invasion of choroid/optic nerve/orbit. Western blotting was performed on 20 tumors using the same antibodies. We observed higher expression of CD9 (P<0.001), E-cadherin (P<0.001) and alpha-catenin (P<0.001) in the non-invasive RB and higher expression of N-cadherin (P<0.001) in invasive RB. The expression of beta-catenin was not significantly different between two groups of tumors. In Western blotting, we were able to see CD9 and E-cadherin expression in a minority of tumors while N-cadherin, alpha-catenin and beta-catenin were expressed with differing intensities in a majority of tumors. Thus, invasive tumors expressed increased N-cadherin, alpha-catenin and decreased E-cadherin and CD9. Thus, it appears that loss of E-cadherin and gain of N-cadherin expression are features of invasiveness. Further functional studies are required to evaluate the role of beta-catenin in RB. PMID:17316610

  8. Galectin-3 Protein Regulates Mobility of N-cadherin and GM1 Ganglioside at Cell-Cell Junctions of Mammary Carcinoma

    E-print Network

    Gleeson, Joseph G.

    Galectin-3 Protein Regulates Mobility of N-cadherin and GM1 Ganglioside at Cell-Cell Junctions Curie, CNRS UMR144, 26 rue d'Ulm, 75248 Paris Cedex 05, France, and the Department of Medical Genetics-cadherin and GM1 ganglioside. Conclusion: Galectin-3 is a novel regulator of N-cadherin dynamics and cell

  9. E-Cadherin Can Replace N-Cadherin during Secretory-Stage Enamel Development

    PubMed Central

    Guan, Xiaomu; Bidlack, Felicitas B.; Stokes, Nicole; Bartlett, John D.

    2014-01-01

    Background N-cadherin is a cell-cell adhesion molecule and deletion of N-cadherin in mice is embryonic lethal. During the secretory stage of enamel development, E-cadherin is down-regulated and N-cadherin is specifically up-regulated in ameloblasts when groups of ameloblasts slide by one another to form the rodent decussating enamel rod pattern. Since N-cadherin promotes cell migration, we asked if N-cadherin is essential for ameloblast cell movement during enamel development. Methodology/Principal Findings The enamel organ, including its ameloblasts, is an epithelial tissue and for this study a mouse strain with N-cadherin ablated from epithelium was generated. Enamel from wild-type (WT) and N-cadherin conditional knockout (cKO) mice was analyzed. ?CT and scanning electron microscopy showed that thickness, surface structure, and prism pattern of the cKO enamel looked identical to WT. No significant difference in hardness was observed between WT and cKO enamel. Interestingly, immunohistochemistry revealed the WT and N-cadherin cKO secretory stage ameloblasts expressed approximately equal amounts of total cadherins. Strikingly, E-cadherin was not normally down-regulated during the secretory stage in the cKO mice suggesting that E-cadherin can compensate for the loss of N-cadherin. Previously it was demonstrated that bone morphogenetic protein-2 (BMP2) induces E- and N-cadherin expression in human calvaria osteoblasts and we show that the N-cadherin cKO enamel organ expressed significantly more BMP2 and significantly less of the BMP antagonist Noggin than did WT enamel organ. Conclusions/Significance The E- to N-cadherin switch at the secretory stage is not essential for enamel development or for forming the decussating enamel rod pattern. E-cadherin can substitute for N-cadherin during these developmental processes. Bmp2 expression may compensate for the loss of N-cadherin by inducing or maintaining E-cadherin expression when E-cadherin is normally down-regulated. Notably, this is the first demonstration of a natural endogenous increase in E-cadherin expression due to N-cadherin ablation in a healthy developing tissue. PMID:25014356

  10. N-cadherin and neuroligins cooperate to regulate synapse formation in hippocampal cultures.

    PubMed

    Aiga, Mytyl; Levinson, Joshua N; Bamji, Shernaz X

    2011-01-01

    Cadherins and neuroligins (NLs) represent two families of cell adhesion proteins that are essential for the establishment of synaptic connections in vitro; however, it remains unclear whether these proteins act in concert to regulate synapse density. Using a combination of overexpression and knockdown analyses in primary hippocampal neurons, we demonstrate that NL1 and N-cadherin promote the formation of glutamatergic synapses through a common functional pathway. Analysis of the spatial relationship between N-cadherin and NL1 indicates that in 14-day in vitro cultures, almost half of glutamatergic synapses are associated with both proteins, whereas only a subset of these synapses are associated with N-cadherin or NL1 alone. This suggests that NL1 and N-cadherin are spatially distributed in a manner that enables cooperation at synapses. In young cultures, N-cadherin clustering and its association with synaptic markers precede the clustering of NL1. Overexpression of N-cadherin at this time point enhances NL1 clustering and increases synapse density. Although N-cadherin is not sufficient to enhance NL1 clustering and synapse density in more mature cultures, knockdown of N-cadherin at later time points significantly attenuates the density of NL1 clusters and synapses. N-cadherin overexpression can partially rescue synapse loss in NL1 knockdown cells, possibly due to the ability of N-cadherin to recruit NL2 to glutamatergic synapses in these cells. We demonstrate that cadherins and NLs can act in concert to regulate synapse formation. PMID:21056983

  11. N-cadherin prodomain processing regulates synaptogenesis.

    PubMed

    Reinés, Analía; Bernier, Louis-Philippe; McAdam, Robyn; Belkaid, Wiam; Shan, Weisong; Koch, Alexander W; Séguéla, Philippe; Colman, David R; Dhaunchak, Ajit S

    2012-05-01

    Classical cadherins, which are adhesion molecules functioning at the CNS synapse, are synthesized as adhesively inactive precursor proteins in the endoplasmic reticulum (ER). Signal sequence and prodomain cleavage in the ER and Golgi apparatus, respectively, activates their adhesive properties. Here, we provide the first evidence for sorting of nonadhesive precursor N-cadherin (ProN) to the neuronal surface, where it coexists with adhesively competent mature N-cadherin (N-cad), generating a spectrum of adhesive strengths. In cultured hippocampal neurons, a high ProN/N-cad ratio downregulates synapse formation. Neurons expressing genetically engineered uncleavable ProN make markedly fewer synapses. The synapse number can be rescued to normality by depleting surface ProN levels through prodomain cleavage by an exogenous protease. Finally, prodomain processing is developmentally regulated in the rat hippocampus. We conclude that it is the ProN/N-cad ratio and not mature N-cad alone that is critical for regulation of adhesion during synaptogenesis. PMID:22553038

  12. N-cadherin expression in malignant germ cell tumours of the testis

    PubMed Central

    2012-01-01

    Background Testicular germ cell tumours (TGCTs) are the most common malignancy in young men aged 18–35 years. They are clinically and histologically subdivided into seminomas and non-seminomas. Cadherins are calcium-dependent transmembrane proteins of the group of adhesion proteins. They play a role in the stabilization of cell-cell contacts, the embryonic morphogenesis, in the maintenance of cell polarity and signal transduction. N-cadherin (CDH2), the neuronal cadherin, stimulates cell-cell contacts during migration and invasion of cells and is able to suppress tumour cell growth. Methods Tumour tissues were acquired from 113 male patients and investigated by immunohistochemistry, as were the three TGCT cell lines NCCIT, NTERA-2 and Tcam2. A monoclonal antibody against N-cadherin was used. Results Tumour-free testis and intratubular germ cell neoplasias (unclassified) (IGCNU) strongly expressed N-cadherin within the cytoplasm. In all seminomas investigated, N-cadherin expression displayed a membrane-bound location. In addition, the teratomas and yolk sac tumours investigated also differentially expressed N-cadherin. In contrast, no N-cadherin could be detected in any of the embryonal carcinomas and chorionic carcinomas examined. This expression pattern was also seen in the investigated mixed tumours consisting of seminomas, teratomas, and embryonal carcinoma. Conclusions N-cadherin expression can be used to differentiate embryonal carcinomas and chorionic carcinomas from other histological subtypes of TGCT. PMID:23066729

  13. N-cadherin-mediated cell adhesion determines the plasticity for cell alignment in response to mechanical stretch in cultured cardiomyocytes

    Microsoft Academic Search

    Takahisa Matsuda; Kyoko Takahashi; Tetsurou Nariai; Takashi Ito; Tomoka Takatani; Yasushi Fujio; Junichi Azuma

    2004-01-01

    Mechanical stretch has been implicated as the growth stimuli in the heart. Physiologically, mechanical stretch is reported to contribute to the orientation of cardiomyocytes, though the molecular mechanism remains to be elucidated. This study was designed to make clear functional significances of N-cadherin in plasticity of cell alignment in response to mechanical stretch. Neonatal rat cardiomyocytes, cultured on silicone dishes,

  14. GRIP1 interlinks N-cadherin and AMPA receptors at vesicles to promote combined cargo transport into dendrites.

    PubMed

    Heisler, Frank F; Lee, Han Kyu; Gromova, Kira V; Pechmann, Yvonne; Schurek, Beate; Ruschkies, Laura; Schroeder, Markus; Schweizer, Michaela; Kneussel, Matthias

    2014-04-01

    The GluA2 subunit of AMPA-type glutamate receptors (AMPARs) regulates excitatory synaptic transmission in neurons. In addition, the transsynaptic cell adhesion molecule N-cadherin controls excitatory synapse function and stabilizes dendritic spine structures. At postsynaptic membranes, GluA2 physically binds N-cadherin, underlying spine growth and synaptic modulation. We report that N-cadherin binds to PSD-95/SAP90/DLG/ZO-1 (PDZ) domain 2 of the glutamate receptor interacting protein 1 (GRIP1) through its intracellular C terminus. N-cadherin and GluA2-containing AMPARs are presorted to identical transport vesicles for dendrite delivery, and live imaging reveals cotransport of both proteins. The kinesin KIF5 powers GluA2/N-cadherin codelivery by using GRIP1 as a multilink interface. Notably, GluA2 and N-cadherin use different PDZ domains on GRIP1 to simultaneously bind the transport complex, and interference with either binding motif impairs the turnover of both synaptic cargoes. Depolymerization of microtubules, deletion of the KIF5 motor domain, or specific blockade of AMPAR exocytosis affects delivery of GluA2/N-cadherin vesicles. At the functional level, interference with this cotransport reduces the number of spine protrusions and excitatory synapses. Our data suggest the concept that the multi-PDZ-domain adaptor protein GRIP1 can act as a scaffold at trafficking vesicles in the combined delivery of AMPARs and N-cadherin into dendrites. PMID:24639525

  15. GRIP1 interlinks N-cadherin and AMPA receptors at vesicles to promote combined cargo transport into dendrites

    PubMed Central

    Heisler, Frank F.; Lee, Han Kyu; Gromova, Kira V.; Pechmann, Yvonne; Schurek, Beate; Ruschkies, Laura; Schroeder, Markus; Schweizer, Michaela; Kneussel, Matthias

    2014-01-01

    The GluA2 subunit of AMPA-type glutamate receptors (AMPARs) regulates excitatory synaptic transmission in neurons. In addition, the transsynaptic cell adhesion molecule N-cadherin controls excitatory synapse function and stabilizes dendritic spine structures. At postsynaptic membranes, GluA2 physically binds N-cadherin, underlying spine growth and synaptic modulation. We report that N-cadherin binds to PSD-95/SAP90/DLG/ZO-1 (PDZ) domain 2 of the glutamate receptor interacting protein 1 (GRIP1) through its intracellular C terminus. N-cadherin and GluA2-containing AMPARs are presorted to identical transport vesicles for dendrite delivery, and live imaging reveals cotransport of both proteins. The kinesin KIF5 powers GluA2/N-cadherin codelivery by using GRIP1 as a multilink interface. Notably, GluA2 and N-cadherin use different PDZ domains on GRIP1 to simultaneously bind the transport complex, and interference with either binding motif impairs the turnover of both synaptic cargoes. Depolymerization of microtubules, deletion of the KIF5 motor domain, or specific blockade of AMPAR exocytosis affects delivery of GluA2/N-cadherin vesicles. At the functional level, interference with this cotransport reduces the number of spine protrusions and excitatory synapses. Our data suggest the concept that the multi-PDZ-domain adaptor protein GRIP1 can act as a scaffold at trafficking vesicles in the combined delivery of AMPARs and N-cadherin into dendrites. PMID:24639525

  16. Two-tiered coupling between flowing actin and immobilized N-cadherin/catenin complexes in neuronal growth cones.

    PubMed

    Garcia, Mikael; Leduc, Cécile; Lagardère, Matthieu; Argento, Amélie; Sibarita, Jean-Baptiste; Thoumine, Olivier

    2015-06-01

    Neuronal growth cones move forward by dynamically connecting actin-based motility to substrate adhesion, but the mechanisms at the individual molecular level remain unclear. We cultured primary neurons on N-cadherin-coated micropatterned substrates, and imaged adhesion and cytoskeletal proteins at the ventral surface of growth cones using single particle tracking combined to photoactivated localization microscopy (sptPALM). We demonstrate transient interactions in the second time scale between flowing actin filaments and immobilized N-cadherin/catenin complexes, translating into a local reduction of the actin retrograde flow. Normal actin flow on micropatterns was rescued by expression of a dominant negative N-cadherin construct competing for the coupling between actin and endogenous N-cadherin. Fluorescence recovery after photobleaching (FRAP) experiments confirmed the differential kinetics of actin and N-cadherin, and further revealed a 20% actin population confined at N-cadherin micropatterns, contributing to local actin accumulation. Computer simulations with relevant kinetic parameters modeled N-cadherin and actin turnover well, validating this mechanism. Such a combination of short- and long-lived interactions between the motile actin network and spatially restricted adhesive complexes represents a two-tiered clutch mechanism likely to sustain dynamic environment sensing and provide the force necessary for growth cone migration. PMID:26038554

  17. ICAM-2 regulates vascular permeability and N-cadherin localization through ezrin-radixin-moesin (ERM) proteins and Rac-1 signalling

    PubMed Central

    2014-01-01

    Background Endothelial junctions control functions such as permeability, angiogenesis and contact inhibition. VE-Cadherin (VECad) is essential for the maintenance of intercellular contacts. In confluent endothelial monolayers, N-Cadherin (NCad) is mostly expressed on the apical and basal membrane, but in the absence of VECad it localizes at junctions. Both cadherins are required for vascular development. The intercellular adhesion molecule (ICAM)-2, also localized at endothelial junctions, is involved in leukocyte recruitment and angiogenesis. Results In human umbilical vein endothelial cells (HUVEC), both VECad and NCad were found at nascent cell contacts of sub-confluent monolayers, but only VECad localized at the mature junctions of confluent monolayers. Inhibition of ICAM-2 expression by siRNA caused the appearance of small gaps at the junctions and a decrease in NCad junctional staining in sub-confluent monolayers. Endothelioma lines derived from WT or ICAM-2-deficient mice (IC2neg) lacked VECad and failed to form junctions, with loss of contact inhibition. Re-expression of full-length ICAM-2 (IC2 FL) in IC2neg cells restored contact inhibition through recruitment of NCad at the junctions. Mutant ICAM-2 lacking the binding site for ERM proteins (IC2 ?ERM) or the cytoplasmic tail (IC2 ?TAIL) failed to restore junctions. ICAM-2-dependent Rac-1 activation was also decreased in these mutant cell lines. Barrier function, measured in vitro via transendothelial electrical resistance, was decreased in IC2neg cells, both in resting conditions and after thrombin stimulation. This was dependent on ICAM-2 signalling to the small GTPase Rac-1, since transendothelial electrical resistance of IC2neg cells was restored by constitutively active Rac-1. In vivo, thrombin-induced extravasation of FITC-labeled albumin measured by intravital fluorescence microscopy in the mouse cremaster muscle showed that permeability was increased in ICAM-2-deficient mice compared to controls. Conclusions These results indicate that ICAM-2 regulates endothelial barrier function and permeability through a pathway involving N-Cadherin, ERMs and Rac-1. PMID:24593809

  18. N-Cadherin Redistribution during Synaptogenesis in Hippocampal Neurons

    Microsoft Academic Search

    Deanna L. Benson; Hidekazu Tanaka

    1998-01-01

    Cadherins are homophilic adhesion molecules that, together with their intracellular binding partners the catenins, mediate adhesion and signaling at a variety of intercellular junctions. This study shows that neural (N)-cadherin and b-catenin, an intracellular binding partner for the classic cadherins, are present in axons and dendrites before synapse formation and then cluster at developing synapses between hippocampal neurons. N-cadherin is

  19. Neural Epidermal Growth Factor-Like Like Protein 2 (NELL2) Promotes Aggregation of Embryonic Carcinoma P19 Cells by Inducing N-Cadherin Expression

    PubMed Central

    Choi, Eun Jung; Kim, Dong Yeol; Kim, Kwang Kon; Kim, Byung Sam; Park, Jeong Woo; Lee, Byung Ju

    2014-01-01

    NELL2 was first identified as a mammalian homolog of chick NEL (Neural EGF-like) protein. It is almost exclusively expressed in neurons of the rat brain and has been suggested to play a role in neural differentiation. However, there is still no clear evidence for the detailed function of NELL2 in the differentiation of neurons. In this study, we identified NELL2 function during neural differentiation of mouse embryonic carcinoma P19 cells. Endogenous expression of NELL2 in the P19 cells increased in parallel with the neuronal differentiation induced by retinoic acid (RA). We found that the mouse NELL2 promoter contains RA response elements (RAREs) and that treatment with RA increased NELL2 promoter activity. Transfection of P19 cells with NELL2 expression vectors induced a dramatic increase in cell aggregation, resulting in the facilitation of neural differentiation. Moreover, NELL2 significantly increased N-cadherin expression in the P19 cell. These data suggest that NELL2 plays an important role in the regulation of neuronal differentiation via control of N-cadherin expression and cell aggregation. PMID:24465772

  20. Blocking N-Cadherin Function Disrupts the Epithelial Structure of Differentiating Neural Tissue in the Embryonic Chicken Brain

    Microsoft Academic Search

    Susanne I. I. Ganzler-Odenthal; Christoph Redies

    1998-01-01

    The cell adhesion molecule N-cadherin is ubiquitously ex- pressed in the early neuroepithelium, with strongest expression in the ependymal lining. We blocked the function of N-cadherin during early chicken brain development by injecting antibodies against N-cadherin into the tectal ventricle of embryos at 4-5 d of incubation (embryonic day 4 (E4)-E5). N-cadherin blockage results in massive morphological changes in restricted

  1. N-CADHERIN PRODOMAIN CLEAVAGE REGULATES SYNAPSE FORMATION IN VIVO

    PubMed Central

    Latefi, Nazlie S.; Pedraza, Liliana; Schohl, Anne; Li, Ziwei; Ruthazer, Edward S.

    2009-01-01

    Cadherins are initially synthesized bearing a prodomain that is thought to limit adhesion during early stages of biosynthesis. Functional cadherins lack this prodomain, raising the intriguing possibility that cells may utilize prodomain cleavage as a means to temporally or spatially regulate adhesion after delivery of cadherin to the cell surface. In support of this idea, immunostaining for the prodomain of zebrafish N-cadherin revealed enriched labeling at neuronal surfaces at the soma and along axonal processes. To determine whether post-translational cleavage of the prodomain affects synapse formation, we imaged Rohon-Beard cells in zebrafish embryos expressing GFP-tagged wild-type N-cadherin (NCAD-GFP) or a GFP-tagged N-cadherin mutant expressing an uncleavable prodomain (PRON-GFP) rendering it non-adhesive. NCAD-GFP accumulated at synaptic microdomains in a developmentally regulated manner, and its overexpression transiently accelerated synapse formation. PRON-GFP was much more diffusely distributed along the axon and its overexpression delayed synapse formation. Our results support the notion that N-cadherin serves to stabilize pre- to postsynaptic contacts early in synapse development and suggests that regulated cleavage of the N-cadherin prodomain may be a mechanism by which the kinetics of synaptogenesis are regulated. PMID:19365814

  2. N-cadherin prodomain cleavage regulates synapse formation in vivo.

    PubMed

    Latefi, Nazlie S; Pedraza, Liliana; Schohl, Anne; Li, Ziwei; Ruthazer, Edward S

    2009-07-01

    Cadherins are initially synthesized bearing a prodomain that is thought to limit adhesion during early stages of biosynthesis. Functional cadherins lack this prodomain, raising the intriguing possibility that cells may utilize prodomain cleavage as a means to temporally or spatially regulate adhesion after delivery of cadherin to the cell surface. In support of this idea, immunostaining for the prodomain of zebrafish N-cadherin revealed enriched labeling at neuronal surfaces at the soma and along axonal processes. To determine whether post-translational cleavage of the prodomain affects synapse formation, we imaged Rohon-Beard cells in zebrafish embryos expressing GFP-tagged wild-type N-cadherin (NCAD-GFP) or a GFP-tagged N-cadherin mutant expressing an uncleavable prodomain (PRON-GFP) rendering it nonadhesive. NCAD-GFP accumulated at synaptic microdomains in a developmentally regulated manner, and its overexpression transiently accelerated synapse formation. PRON-GFP was much more diffusely distributed along the axon and its overexpression delayed synapse formation. Our results support the notion that N-cadherin serves to stabilize pre- to postsynaptic contacts early in synapse development and suggests that regulated cleavage of the N-cadherin prodomain may be a mechanism by which the kinetics of synaptogenesis are regulated. PMID:19365814

  3. N-Cadherin Relocalizes from the Periphery to the Center of the Synapse after Transient Synaptic Stimulation in Hippocampal Neurons

    PubMed Central

    Yam, Patricia T.; Pincus, Zachary; Gupta, Gagan D.; Bashkurov, Mikhail; Charron, Frédéric; Pelletier, Laurence; Colman, David R.

    2013-01-01

    N-cadherin is a cell adhesion molecule which is enriched at synapses. Binding of N-cadherin molecules to each other across the synaptic cleft has been postulated to stabilize adhesion between the presynaptic bouton and the postsynaptic terminal. N-cadherin is also required for activity-induced changes at synapses, including hippocampal long term potentiation and activity-induced spine expansion and stabilization. We hypothesized that these activity-dependent changes might involve changes in N-cadherin localization within synapses. To determine whether synaptic activity changes the localization of N-cadherin, we used structured illumination microscopy, a super-resolution approach which overcomes the conventional resolution limits of light microscopy, to visualize the localization of N-cadherin within synapses of hippocampal neurons. We found that synaptic N-cadherin exhibits a spectrum of localization patterns, ranging from puncta at the periphery of the synapse adjacent to the active zone to an even distribution along the synaptic cleft. Furthermore, the N-cadherin localization pattern within synapses changes during KCl depolarization and after transient synaptic stimulation. During KCl depolarization, N-cadherin relocalizes away from the central region of the synaptic cleft to the periphery of the synapse. In contrast, after transient synaptic stimulation with KCl followed by a period of rest in normal media, fewer synapses have N-cadherin present as puncta at the periphery and more synapses have N-cadherin present more centrally and uniformly along the synapse compared to unstimulated cells. This indicates that transient synaptic stimulation modulates N-cadherin localization within the synapse. These results bring new information to the structural organization and activity-induced changes occurring at synapses, and suggest that N-cadherin relocalization may contribute to activity dependent changes at synapses. PMID:24223993

  4. N-cadherin-catenin complexes form prior to cleavage of the proregion and transport to the plasma membrane.

    PubMed

    Wahl, James K; Kim, Young J; Cullen, Janet M; Johnson, Keith R; Wheelock, Margaret J

    2003-05-01

    Cadherins are calcium-dependent glycoproteins that function as cell-cell adhesion molecules and are linked to the actin cytoskeleton via catenins. Newly synthesized cadherins contain a prosequence that must be proteolytically removed to generate a functional adhesion molecule. The goal of this study was to examine the proteolytic processing of N-cadherin and the assembly of the cadherin-catenin complex in cells that express endogenous N-cadherin. A monoclonal antibody specific for the proregion of human N-cadherin was generated and used to examine N-cadherin processing. Our data show that newly synthesized proN-cadherin is phosphorylated and proteolytically processed prior to transport to the plasma membrane. In addition, we show that beta-catenin and plakoglobin associate only with phosphorylated proN-cadherin, whereas p120(ctn) can associate with both phosphorylated and non-phosphorylated proN-cadherin. Immunoprecipitations using anti-proN-cadherin showed that cadherin-catenin complexes are assembled prior to localization at the plasma membrane. These data suggest that a core N-cadherin-catenin complex assembles in the endoplasmic reticulum or Golgi compartment and is transported to the plasma membrane where linkage to the actin cytoskeleton can be established. PMID:12604612

  5. Expression of N-cadherin by human squamous carcinoma cells induces a scattered fibroblastic phenotype with disrupted cell-cell adhesion

    Microsoft Academic Search

    Shahidul Islam; Thomas E. Carey; Gregory T. Wolf; Margaret J. Wheelock; Keith R. Johnson

    1996-01-01

    E-cadherin is a transmembrane glycoprotein that mediates calcium-dependent, homotypic cell-cell adhesion and plays an important role in maintaining the normal phenotype of epithelial cells. Disruption of E-cadherin activity in epithelial cells correlates with formation of metastatic tumors. Decreased adhesive function may be implemented in a number of ways in- cluding: (a) decreased expression of E-cadherin; (b) mutations in the gene

  6. Coordination of synaptic adhesion with dendritic spine remodeling by AF-6 and kalirin-7

    PubMed Central

    Xie, Zhong; Photowala, Huzefa; Cahill, Michael E.; Srivastava, Deepak P.; Woolfrey, Kevin M.; Shum, Cassandra Y.; Huganir, Richard L.; Penzes, Peter

    2009-01-01

    Remodeling of central excitatory synapses is crucial for synapse maturation, plasticity, and contributes to neurodevelopmental and psychiatric disorders. Remodeling of dendritic spines and the associated synapses, has been postulated to require the coordination of adhesion with spine morphology and stability; however, the molecular mechanisms that functionally link adhesion molecules with regulators of dendritic spine morphology are largely unknown. Here we report that spine size and N-cadherin content are tightly coordinated. In rat mature cortical pyramidal neurons, N-cadherin-dependent adhesion modulates the morphology of existing spines by recruiting the Rac1 guanine-nucleotide exchange factor kalirin-7 to synapses through the scaffolding protein AF-6/afadin. In pyramidal neurons, N-cadherin, AF-6, and kalirin-7 colocalize at synapses and participate in the same multiprotein complexes. N-cadherin clustering promotes the reciprocal interaction and recruitment of N-cadherin, AF-6, and kalirin-7, increasing the content of Rac1 and in spines and PAK phosphorylation. N-cadherin-dependent spine enlargement requires AF-6 and kalirin-7 function. Conversely, disruption of N-cadherin leads to thin, long spines, with reduced Rac1 contact, caused by uncoupling of N-cadherin, AF-6, and kalirin-7 from each other. By dynamically linking N-cadherin with a regulator of spine plasticity, this pathway allows synaptic adhesion molecules to rapidly coordinate spine remodeling associated with synapse maturation and plasticity. This study hence identifies a novel mechanism whereby cadherins, a major class of synaptic adhesion molecules, signal to the actin cytoskeleton to control the morphology of dendritic spines, and outlines a mechanism that underlies the coordination of synaptic adhesion with spine morphology. PMID:18550750

  7. Glioma stem cell invasion through regulation of the interconnected ERK, integrin ?6 and N-cadherin signaling pathway.

    PubMed

    Velpula, Kiran Kumar; Rehman, Azeem A; Chelluboina, Bharath; Dasari, Venkata Ramesh; Gondi, Christopher S; Rao, Jasti S; Veeravalli, Krishna Kumar

    2012-11-01

    The recent characterization of glioma stem cells (GSCs) prompts a necessary examination of the signaling pathways that facilitate invasiveness. Molecular crosstalk between expression mechanisms has been identified in a range of cancers, including glioblastoma multiforme. However, hardly any literature exists that addresses whether cancer stem cells utilize these same interconnected pathways. Protein factors commonly implicated in malignant tumors include extracellular signal-regulated kinase (ERK), N-cadherin, and integrin ?6. Although studies have reported the molecular crosstalk involved among these proteins, the present study illustrates the importance of the ERK transduction pathway in N-cadherin and integrin ?6 regulated invasion in GSCs. Conversely, the data also suggests that GSCs rely on N-cadherin and integrin ?6 interaction to regulate ERK signaling. Moreover, confocal visualization revealed the co-localization of N-cadherin and integrin ?6 in GSCs and clinical surgical biopsies extracted from glioma patients. Interestingly, ERK knockdown reduced this co-localization. Upon co-culturing GSCs with human umbilical cord blood stem cells (hUCBSCs), we observed a subsequent decrease in pERK, N-cadherin and integrin ?6 expression. In addition, co-culturing hUCBSCs with GSCs decreased co-localization of N-cadherin and integrin ?6 in GSCs. Our results demonstrate the dynamic interplay among ERK, N-cadherin and integrin ?6 in GSC invasion and also reveal the therapeutic potential of hUCBSCs in treating the molecular crosstalk observed in GSC-regulated invasion. PMID:22789454

  8. Recruitment of ?-catenin to N-cadherin is necessary for smooth muscle contraction.

    PubMed

    Wang, Tao; Wang, Ruping; Cleary, Rachel A; Gannon, Olivia J; Tang, Dale D

    2015-04-01

    ?-Catenin is a key component that connects transmembrane cadherin with the actin cytoskeleton at the cell-cell interface. However, the role of the ?-catenin/cadherin interaction in smooth muscle has not been well characterized. Here stimulation with acetylcholine promoted the recruitment of ?-catenin to N-cadherin in smooth muscle cells/tissues. Knockdown of ?-catenin by lentivirus-mediated shRNA attenuated smooth muscle contraction. Nevertheless, myosin light chain phosphorylation at Ser-19 and actin polymerization in response to contractile activation were not reduced by ?-catenin knockdown. In addition, the expression of the ?-catenin armadillo domain disrupted the recruitment of ?-catenin to N-cadherin. Force development, but not myosin light chain phosphorylation and actin polymerization, was reduced by the expression of the ?-catenin armadillo domain. Furthermore, actin polymerization and microtubules have been implicated in intracellular trafficking. In this study, the treatment with the inhibitor latrunculin A diminished the interaction of ?-catenin with N-cadherin in smooth muscle. In contrast, the exposure of smooth muscle to the microtubule depolymerizer nocodazole did not affect the protein-protein interaction. Together, these findings suggest that smooth muscle contraction is mediated by the recruitment of ?-catenin to N-cadherin, which may facilitate intercellular mechanotransduction. The association of ?-catenin with N-cadherin is regulated by actin polymerization during contractile activation. PMID:25713069

  9. Engineered N-cadherin and L1 biomimetic substrates concertedly promote neuronal differentiation, neurite extension and neuroprotection of human neural stem cells.

    PubMed

    Cherry, Jocie F; Bennett, Neal K; Schachner, Melitta; Moghe, Prabhas V

    2014-10-01

    We investigated the design of neurotrophic biomaterial constructs for human neural stem cells, guided by neural developmental cues of N-cadherin and L1 adhesion molecules. Polymer substrates fabricated either as two-dimensional (2-D) films or three-dimensional (3-D) microfibrous scaffolds were functionalized with fusion chimeras of N-cadherin-Fc alone and in combination with L1-Fc, and the effects on differentiation, neurite extension and survival of H9 human-embryonic-stem-cell-derived neural stem cells (H9-NSCs) were quantified. Combinations of N-cadherin and L1-Fc co-operatively enhanced neuronal differentiation profiles, indicating the critical nature of the two complementary developmental cues. Notably, substrates presenting low levels of N-cadherin-Fc concentrations, combined with proportionately higher L1-Fc concentration, most enhanced neurite outgrowth and the degree of MAP2+ and neurofilament-M+ H9-NSCs. Low N-cadherin-Fc alone promoted improved cell survival following oxidative stress, compared to higher concentrations of N-cadherin-Fc alone or combinations with L1-Fc. Pharmacological and antibody blockage studies revealed that substrates presenting low levels of N-cadherin are functionally competent so long as they elicit a threshold signal mediated by homophilic N-cadherin and fibroblast growth factor signaling. Overall, these studies highlight the ability of optimal combinations of N-cadherin and L1 to recapitulate a "neurotrophic" microenvironment that enhances human neural stem cell differentiation and neurite outgrowth. Additionally, 3-D fibrous scaffolds presenting low N-cadherin-Fc further enhanced the survival of H9-NSCs compared to equivalent 2-D films. This indicates that similar biofunctionalization approaches based on N-cadherin and L1 can be translated to 3-D "transplantable" scaffolds with enhanced neurotrophic behaviors. Thus, the insights from this study have fundamental and translational impacts for neural-stem-cell-based regenerative medicine. PMID:24914828

  10. Protein mediated membrane adhesion

    NASA Astrophysics Data System (ADS)

    Carlson, Andreas; Mahadevan, L.

    2015-05-01

    Adhesion in the context of mechanical attachment, signaling, and movement in cellular dynamics is mediated by the kinetic interactions between membrane-embedded proteins in an aqueous environment. Here, we present a minimal theoretical framework for the dynamics of membrane adhesion that accounts for the kinetics of protein binding, the elastic deformation of the membrane, and the hydrodynamics of squeeze flow in the membrane gap. We analyze the resulting equations using scaling estimates to characterize the spatiotemporal features of the adhesive patterning and corroborate them using numerical simulations. In addition to characterizing aspects of cellular dynamics, our results might also be applicable to a range of phenomena in physical chemistry and materials science where flow, deformation, and kinetics are coupled to each other in slender geometries.

  11. Lateral assembly of N-cadherin drives tissue integrity by stabilizing adherens junctions.

    PubMed

    Garg, S; Fischer, S C; Schuman, E M; Stelzer, E H K

    2015-03-01

    Cadherin interactions ensure the correct registry and anchorage of cells during tissue formation. Along the plasma membrane, cadherins form inter-junctional lattices via cis- and trans-dimerization. While structural studies have provided models for cadherin interactions, the molecular nature of cadherin binding in vivo remains unexplored. We undertook a multi-disciplinary approach combining live cell imaging of three-dimensional cell assemblies (spheroids) with a computational model to study the dynamics of N-cadherin interactions. Using a loss-of-function strategy, we demonstrate that each N-cadherin interface plays a distinct role in spheroid formation. We found that cis-dimerization is not a prerequisite for trans-interactions, but rather modulates trans-interfaces to ensure tissue stability. Using a model of N-cadherin junction dynamics, we show that the absence of cis-interactions results in low junction stability and loss of tissue integrity. By quantifying the binding and unbinding dynamics of the N-cadherin binding interfaces, we determined that mutating either interface results in a 10-fold increase in the dissociation constant. These findings provide new quantitative information on the steps driving cadherin intercellular adhesion and demonstrate the role of cis-interactions in junction stability. PMID:25589573

  12. N-cadherin prevents the premature differentiation of anterior heart field progenitors in the pharyngeal mesodermal microenvironment

    PubMed Central

    Soh, Boon-Seng; Buac, Kristina; Xu, Huansheng; Li, Edward; Ng, Shi-Yan; Wu, Hao; Chmielowiec, Jolanta; Jiang, Xin; Bu, Lei; Li, Ronald A; Cowan, Chad; Chien, Kenneth R

    2014-01-01

    The cardiac progenitor cells (CPCs) in the anterior heart field (AHF) are located in the pharyngeal mesoderm (PM), where they expand, migrate and eventually differentiate into major cell types found in the heart, including cardiomyocytes. The mechanisms by which these progenitors are able to expand within the PM microenvironment without premature differentiation remain largely unknown. Through in silico data mining, genetic loss-of-function studies, and in vivo genetic rescue studies, we identified N-cadherin and interaction with canonical Wnt signals as a critical component of the microenvironment that facilitates the expansion of AHF-CPCs in the PM. CPCs in N-cadherin mutant embryos were observed to be less proliferative and undergo premature differentiation in the PM. Notably, the phenotype of N-cadherin deficiency could be partially rescued by activating Wnt signaling, suggesting a delicate functional interaction between the adhesion role of N-cadherin and Wnt signaling in the early PM microenvironment. This study suggests a new mechanism for the early renewal of AHF progenitors where N-cadherin provides additional adhesion for progenitor cells in the PM, thereby allowing Wnt paracrine signals to expand the cells without premature differentiation. PMID:25367124

  13. Inflammatory Bowel Disease and Adenomas in Mice Expressing a Dominant Negative N-Cadherin

    Microsoft Academic Search

    Michelle L. Hermiston; Jeffrey I. Gordon

    1995-01-01

    Cadherins mediate cell adhesion and are essential for normal development. Embryonic stem cells were transfected with a dominant negative N-cadherin mutant (NCADDelta) under the control of promoters active in small intestinal epithelial cells and then introduced into C57BL\\/6 mouse blastocysts. Analysis of adult chimeric mice revealed that expression of NCADDelta along the entire crypt-villus axis, but not in the villus

  14. The kinase domains of obscurin interact with intercellular adhesion proteins.

    PubMed

    Hu, Li-Yen R; Kontrogianni-Konstantopoulos, Aikaterini

    2013-05-01

    Obscurins comprise a family of giant (~870- to 600-kDa) and small (~250- to 55-kDa) proteins that play important roles in myofibrillogenesis, cytoskeletal organization, and cell adhesion and are implicated in hypertrophic cardiomyopathy and tumorigenesis. Giant obscurins are composed of tandem structural and signaling motifs, including 2 serine/threonine kinase domains, SK1 and SK2, present at the COOH terminus of giant obscurin-B. Using biochemical and cellular approaches, we show for the first time that both SK1 and SK2 possess enzymatic activities and undergo autophosphorylation. SK2 can phosphorylate the cytoplasmic domain of N-cadherin, a major component of adherens junctions, and SK1 can interact with the extracellular domain of the ?1-subunit of the Na(+)/K(+)-ATPase, which also resides in adherens junctions. Immunostaining of nonpermeabilized myofibers and cardiocytes revealed that some obscurin kinase isoforms localize extracellularly. Quantification of the exofacial expression of obscurin kinase proteins indicated that they occupy ~16 and ~5% of the sarcolemmal surface in myofibers and cardiocytes, respectively. Treatment of heart lysates with peptide-N-glycosidase F revealed that while giant obscurin-B localizes intracellularly, possessing dual kinase activity, a small obscurin kinase isoform that contains SK1 localizes extracellularly, where it undergoes N-glycosylation. Collectively, our studies demonstrate that the obscurin kinase domains are enzymatically active and may be involved in the regulation of cell adhesion. PMID:23392350

  15. PTP m Regulates N-Cadherin-dependent Neurite Outgrowth

    Microsoft Academic Search

    Susan M. Burden-Gulley; Susann M. Brady-Kalnay

    Cell adhesion is critical to the establishment of proper connections in the nervous system. Some re- ceptor-type protein tyrosine phosphatases (RPTPs) have adhesion molecule-like extracellular segments with intracellular tyrosine phosphatase domains that may transduce signals in response to adhesion. PTP m is a RPTP that mediates cell aggregation and is expressed at high levels in the nervous system. In this

  16. Surface Expression of Precursor N-cadherin Promotes Tumor Cell Invasion12

    PubMed Central

    Maret, Deborah; Gruzglin, Eugenia; Sadr, Mohamad Seyed; Siu, Vincent; Shan, Weisong; Koch, Alexander W; Seidah, Nabil G; Del Maestro, Rolando F; Colman, David R

    2010-01-01

    The expression of N-cadherin (NCAD) has been shown to correlate with increased tumor cell motility and metastasis. However, NCAD-mediated adhesion is a robust phenomenon and therefore seems to be inconsistent with the “release” from intercellular adhesion required for invasion. We show that in the most invasive melanoma and brain tumor cells, altered posttranslational processing results in abundant nonadhesive precursor N-cadherin (proNCAD) at the cell surface, although total NCAD levels remain constant. We demonstrate that aberrantly processed proNCAD promotes cell migration and invasion in vitro. Furthermore, in human tumor specimens, we find high levels of proNCAD as well, supporting an overall conclusion that proNCAD and mature NCAD coexist on these tumor cell surfaces and that it is the ratio between these functionally antagonistic moieties that directly correlates with invasion potential. Our work provides insight into what may be a widespread mechanism for invasion and metastasis and challenges the current dogma of the functional roles played by classic cadherins in tumor progression. PMID:21170270

  17. Oncologic trogocytosis with Hospicells induces the expression of N-cadherin by breast cancer cells.

    PubMed

    Lis, Raphaël; Capdet, Jérome; Mirshahi, Pejman; Lacroix-Triki, Magali; Dagonnet, Francoise; Klein, Christophe; Mirshahi, Massoud; Fournié, Jean-Jacques; Rafii, Arash; Poupot, Mary

    2010-12-01

    In breast cancers, the appearance of metastasis is synonymous with poor prognosis. The metastatic process is usually associated with epithelial-mesenchymal transition (EMT) which is often induced by several soluble factors produced either by the tumour cells themselves or by cells constituting the tumour microenvironment. The aim of the present study was to determine whether the mesenchymal properties given by some molecules such as N-cadherin, for instance, could be acquired by cancer cells via the trogocytosis process with cells of the tumour microenvironment. Hospicells are stromal cells which were first isolated from cancer cell aggregates of patients with ovarian cancer. We recently showed that these cells are immunosuppressive for T lymphocyte functions and confer chemoresistance to cancer cells by the transfer of the MDR protein via trogocytosis. In this study, we showed that a mammary cancer cell line (MDA-MB-231) acquires patches of membrane via oncologic trogocytosis with Hospicells. This unidirectional and active process depends on actin polymerization and can be increased via inhibition of the Src family and decreased via inhibition of PI3K. Trogocytosis between Hospicells and MDA-MB-231 does not lead to the direct acquisition of N-cadherin but rather it leads to the production of soluble factor(s) which induce de novo expression of N-cadherin by the cancer cells. The novelty here is that this factor is produced only if cancer cells interact and undergo trogocytosis with Hospicells. This new expression could confer a more invasive phenotype to the cancer cells and thus can explain the correlation of the presence of Hospicells with the number of invaded lymph nodes in patients with mammary adenocarcinoma. PMID:21042713

  18. Involvement of N-cadherin/?-catenin interaction in the micro/nanotopography induced indirect mechanotransduction.

    PubMed

    Liu, Qian; Wang, Wei; Zhang, Li; Zhao, Lingzhou; Song, Wen; Duan, Xiaohong; Zhang, Yumei

    2014-08-01

    Topographical modification at micro- and nanoscale is widely applied to enhance the tissue integration properties of biomaterials, but the underlying molecular mechanism is poorly understood. The biomaterial topography modulates cell functions via mechanotransduction of direct and indirect. We propose that N-cadherin may play a role in the topographically induced indirect mechanotransduction by regulating the ?-catenin signaling. For confirmation, the cell functions, N-cadherin expression and ?-catenin signaling activation of osteoblasts on titanium (Ti) surfaces with micro- or/and nanotopography are systemically compared with naive and N-cadherin down-regulating MC3T3-E1 cells. We find that the N-cadherin expression is reversely related to the intracellular ?-catenin signaling and the N-cadherin/?-catenin signaling is modulated differentially by the micro- and nanotopography. The nanotopography significantly up-regulates the N-cadherin expression leading to lower ?-catenin signaling activity and consequently depressed differentiation, whereas the microtopography down-regulates the N-cadherin expression resulting in enhanced ?-catenin signaling and thus osteoblast differentiation. Artificial down-regulation of the N-cadherin expression can significantly up-regulate the ?-catenin signaling and consequently enhance the osteoblast differentiation on all the Ti surfaces. The study for the first time clarifies the involvement of the N-cadherin/?-catenin interaction in the micro/nanotopography induced indirect mechanotransduction and provides a potentially new approach for biomaterial modification and biofunctionalization by down-regulating the cell N-cadherin expression to achieve improved clinical performance. PMID:24818888

  19. N-cadherin, a novel prognostic biomarker, drives malignant progression of colorectal cancer.

    PubMed

    Yan, Xuebing; Yan, Leilei; Liu, Sihong; Shan, Zezhi; Tian, Yuan; Jin, Zhiming

    2015-08-01

    Recent studies have indicated that the epithelial-mesenchymal transition (EMT) is a key molecular mechanism involved in the development of colorectal cancer (CRC). N-cadherin is a mesenchymal marker of the EMT and has been closely linked to several human malignancies. However, its role in CRC has remained elusive. In the present study, qRT?PCR and western blot analysis indicated that N?cadherin expression was higher in tumor tissues than in that in their adjacent normal tissues. Immunohistochemical evaluation of N?cadherin and E?cadherin (an epithelial marker of the EMT), indicated that N?cadherin expression was significantly associated with tumor differentiation, tumor size as well as tumor, nodes and metastasis stage. Correlation analysis suggested the expression of N?cadherin was negatively correlated with that of E?cadherin in CRC tissues. Kaplan?Meier analysis indicated that patients with high N?cadherin expression had a significantly lower overall survival and disease?free survival rate than those with low N?cadherin expression, while the opposite was found for E?cadherin. Of note, the present study found that high N?cadherin expression was an independent prognostic factor for CRC. In vitro assays showed that N?cadherin was widely expressed in CRC cell lines and silencing of N?cadherin suppressed the proliferation and migration of the CRC cell line HT?29 by upregulating E?cadherin, suggesting a potential role of N?cadherin in inducing EMT. In conclusion, the present study suggested that N?cadherin has the potential of serving as a novel prognostic predictor and a promising therapeutic target for CRC. PMID:25936636

  20. An Occludin-Focal Adhesion Kinase Protein Complex at the Blood-Testis Barrier: A Study Using the Cadmium Model

    PubMed Central

    Siu, Erica R.; Wong, Elissa W. P.; Mruk, Dolores D.; Sze, K. L.; Porto, Catarina S.; Cheng, C. Yan

    2009-01-01

    Several integral membrane proteins that constitute the blood-testis barrier (BTB) in mammalian testes, in particular rodents, are known to date. These include tight junction (TJ) proteins (e.g. occludin, junctional adhesion molecule-A, claudins), basal ectoplasmic specialization proteins (e.g. N-cadherin), and gap junction proteins (e.g. connexin43). However, the regulators (e.g. protein kinases and phosphatases) that affect these proteins, such as their interaction with the cytoskeletal actin, which in turn confer cell adhesion at the TJ, remain largely unknown. We report herein that focal adhesion kinase (FAK) is a putative interacting partner of occludin, but not claudin-11 or junctional adhesion molecule-A. Immunohistochemistry and fluorescence microscopy studies illustrated that the expression of FAK in the seminiferous epithelium of adult rat testes was stage specific. FAK colocalized with occludin at the BTB in virtually all stages of the seminiferous epithelial cycle but considerably diminished in stages VIII–IX, at the time of BTB restructuring to facilitate the transit of primary leptotene spermatocytes. Using Sertoli cells cultured in vitro with established TJ-permeability barrier and ultrastructures of TJ, basal ectoplasmic specialization and desmosome-like junction that mimicked the BTB in vivo, FAK was shown to colocalize with occludin and zonula occludens-1 (ZO-1) at the Sertoli-Sertoli cell interface. When these Sertoli cell cultures were treated with CdCl2 to perturb the TJ-barrier function, occludin underwent endocytic-mediated internalization in parallel with FAK and ZO-1. Thus, these findings demonstrate that FAK is an integrated regulatory component of the occludin-ZO-1 protein complex, suggesting that functional studies can be performed to study the role of FAK in BTB dynamics. PMID:19213829

  1. ADAM-10 could mediate cleavage of N-cadherin promoting apoptosis in human atherosclerotic lesions leading to vulnerable plaque: a morphological and immunohistochemical study.

    PubMed

    Musumeci, Giuseppe; Coleman, Raymond; Imbesi, Rosa; Magro, Gaetano; Parenti, Rosalba; Szychlinska, Marta Anna; Scuderi, Rosario; Cinà, Claudio Salvatore; Castorina, Sergio; Castrogiovanni, Paola

    2014-09-01

    Atherosclerosis remains a major cause of mortality. Whereas the histopathological progression of atherosclerotic lesions is well documented, much less is known about the development of unstable or vulnerable plaque, which can rupture leading to thrombus, luminal occlusion and infarct. Apoptosis in the fibrous cap, which is rich in vascular smooth muscle cells (VSMCs) and macrophages, and its subsequent weakening or erosion seems to be an important regulator of plaque stability. The aim of our study was to improve our knowledge on the biological mechanisms that cause plaque instability in order to develop new therapies to maintain atherosclerotic plaque stability and avoid its rupture. In our study, we collected surgical specimens from atherosclerotic plaques in the right or left internal carotid artery of 62 patients with evident clinical symptoms. Histopathology and histochemistry were performed on wax-embedded sections. Immunohistochemical localization of caspase-3, N-cadherin and ADAM-10 was undertaken in order to highlight links between apoptosis, as expressed by caspase-3 immunostaining, and possible roles of N-cadherin, a cell-cell junction protein in VSMCs and macrophages that provides a pro-survival signal reducing apoptosis, and ADAM-10, a "disintegrin and metalloproteases" that is able to cleave N-cadherin in glioblastomas. Our results showed that when apoptosis, expressed by caspase-3 immunostaining, increased in the fibrous cap, rich in VSMCs and macrophages, the expression of N-cadherin decreased. The decreased N-cadherin expression, in turn, was linked to increased ADAM-10 expression. This study shows that apoptotic events are probably involved in the vulnerability of atherosclerotic plaque. PMID:24985126

  2. Intervention Effects of Ganoderma Lucidum Spores on Epileptiform Discharge Hippocampal Neurons and Expression of Neurotrophin-4 and N-Cadherin

    PubMed Central

    Wang, Shu-Qiu; Li, Xiao-Jie; Zhou, Shaobo; Sun, Di-Xiang; Wang, Hui; Cheng, Peng-Fei; Ma, Xiao-Ru; Liu, Lei; Liu, Jun-Xing; Wang, Fang-Fang; Liang, Yan-Feng; Wu, Jia-Mei

    2013-01-01

    Epilepsy can cause cerebral transient dysfunctions. Ganoderma lucidum spores (GLS), a traditional Chinese medicinal herb, has shown some antiepileptic effects in our previous studies. This was the first study of the effects of GLS on cultured primary hippocampal neurons, treated with Mg2+ free medium. This in vitro model of epileptiform discharge hippocampal neurons allowed us to investigate the anti-epileptic effects and mechanism of GLS activity. Primary hippocampal neurons from <1 day old rats were cultured and their morphologies observed under fluorescence microscope. Neurons were confirmed by immunofluorescent staining of neuron specific enolase (NSE). Sterile method for GLS generation was investigated and serial dilutions of GLS were used to test the maximum non-toxic concentration of GLS on hippocampal neurons. The optimized concentration of GLS of 0.122 mg/ml was identified and used for subsequent analysis. Using the in vitro model, hippocampal neurons were divided into 4 groups for subsequent treatment i) control, ii) model (incubated with Mg2+ free medium for 3 hours), iii) GLS group I (incubated with Mg2+ free medium containing GLS for 3 hours and replaced with normal medium and incubated for 6 hours) and iv) GLS group II (neurons incubated with Mg2+ free medium for 3 hours then replaced with a normal medium containing GLS for 6 hours). Neurotrophin-4 and N-Cadherin protein expression were detected using Western blot. The results showed that the number of normal hippocampal neurons increased and the morphologies of hippocampal neurons were well preserved after GLS treatment. Furthermore, the expression of neurotrophin-4 was significantly increased while the expression of N-Cadherin was decreased in the GLS treated group compared with the model group. This data indicates that GLS may protect hippocampal neurons by promoting neurotrophin-4 expression and inhibiting N-Cadherin expression. PMID:23637882

  3. Intervention effects of ganoderma lucidum spores on epileptiform discharge hippocampal neurons and expression of neurotrophin-4 and N-cadherin.

    PubMed

    Wang, Shu-Qiu; Li, Xiao-Jie; Zhou, Shaobo; Sun, Di-Xiang; Wang, Hui; Cheng, Peng-Fei; Ma, Xiao-Ru; Liu, Lei; Liu, Jun-Xing; Wang, Fang-Fang; Liang, Yan-Feng; Wu, Jia-Mei

    2013-01-01

    Epilepsy can cause cerebral transient dysfunctions. Ganoderma lucidum spores (GLS), a traditional Chinese medicinal herb, has shown some antiepileptic effects in our previous studies. This was the first study of the effects of GLS on cultured primary hippocampal neurons, treated with Mg(2+) free medium. This in vitro model of epileptiform discharge hippocampal neurons allowed us to investigate the anti-epileptic effects and mechanism of GLS activity. Primary hippocampal neurons from <1 day old rats were cultured and their morphologies observed under fluorescence microscope. Neurons were confirmed by immunofluorescent staining of neuron specific enolase (NSE). Sterile method for GLS generation was investigated and serial dilutions of GLS were used to test the maximum non-toxic concentration of GLS on hippocampal neurons. The optimized concentration of GLS of 0.122 mg/ml was identified and used for subsequent analysis. Using the in vitro model, hippocampal neurons were divided into 4 groups for subsequent treatment i) control, ii) model (incubated with Mg(2+) free medium for 3 hours), iii) GLS group I (incubated with Mg(2+) free medium containing GLS for 3 hours and replaced with normal medium and incubated for 6 hours) and iv) GLS group II (neurons incubated with Mg(2+) free medium for 3 hours then replaced with a normal medium containing GLS for 6 hours). Neurotrophin-4 and N-Cadherin protein expression were detected using Western blot. The results showed that the number of normal hippocampal neurons increased and the morphologies of hippocampal neurons were well preserved after GLS treatment. Furthermore, the expression of neurotrophin-4 was significantly increased while the expression of N-Cadherin was decreased in the GLS treated group compared with the model group. This data indicates that GLS may protect hippocampal neurons by promoting neurotrophin-4 expression and inhibiting N-Cadherin expression. PMID:23637882

  4. Molecular mechanics of mussel adhesion proteins

    NASA Astrophysics Data System (ADS)

    Qin, Zhao; Buehler, Markus J.

    2014-01-01

    Mussel foot protein (mfp), a natural glue produced by marine mussel, is an intriguing material because of its superior ability for adhesion in various environments. For example, a very small amount of this material is sufficient to affix a mussel to a substrate in water, providing structural support under extreme forces caused by the dynamic effects of waves. Towards a more complete understanding of its strength and underwater workability, it is necessary to understand the microscropic mechanisms by which the protein structure interacts with various substrates. However, none of the mussel proteins' structure is known, preventing us from directly using atomistic modeling to probe their structural and mechanical properties. Here we use an advanced molecular sampling technique to identify the molecular structures of two mussel foot proteins (mfp-3 and mfp-5) and use those structures to study their mechanics of adhesion, which is then incorporated into a continuum model. We calculate the adhesion energy of the mussel foot protein on a silica substrate, compute the adhesion strength based on results obtained from molecular modeling, and compare with experimental data. Our results show good agreement with experimental measurements, which validates the multiscale model. We find that the molecular structure of the folded mussel foot protein (ultimately defined by its genetic sequence) favors strong adhesion to substrates, where L-3,4-dihydroxyphenylalanine (or DOPA) protein subunits work in a cooperative manner to enhance adhesion. Our experimental data suggests a peak attachment force of 0.4±0.1 N, which compares favorably with the prediction from the multiscale model of Fc=0.21-0.33 N. The principles learnt from those results could guide the fabrication of new interfacial materials (e.g. composites) to integrate organic with inorganic surfaces in an effective manner.

  5. N-cadherin prodomain cleavage regulates synapse formation in vivo

    Microsoft Academic Search

    Nazlie S. Latefi; Liliana Pedraza; Anne Schohl; Ziwei Li; Edward S. Ruthazer

    2009-01-01

    Cadherins are initially synthesized bearing a prodomain that is thought to limit adhesion during early stages of biosynthesis. Functional cadherins lack this prodomain, raising the intriguing possibility that cells may utilize prodomain cleavage as a means to tempo- rally or spatially regulate adhesion after delivery of cad- herin to the cell surface. In support of this idea, immuno- staining for

  6. An adhesive protein capsule of Escherichia coli.

    PubMed Central

    Orskov, I; Birch-Andersen, A; Duguid, J P; Stenderup, J; Orskov, F

    1985-01-01

    The nature of the adhesive capacity of three hemagglutinating Escherichia coli strains that had earlier been described as nonfimbriated was studied. The strains that were isolated from human disease adhered to human buccal and urinary tract epithelial cells, an adhesion that was not inhibited by D-mannose. By crossed immunoelectrophoresis it was shown that the three strains produced a common antigen, Z1, developed after growth at 37 degrees C but not 18 degrees C. One of the strains produced an additional antigen, Z2, of almost the same electrophoretic mobility in crossed immunoelectrophoresis. A mutant of this strain deficient of its polysaccharide K antigen had maintained the adhesive capacity, indicating that the K antigen was not responsible for adhesion. A further mutant of the acapsular mutant produced a strongly reduced amount of the Z antigens and had lost the ability to adhere. The Z1 (and Z2?) antigens were therefore deemed to be responsible for adhesion. In sodium dodecyl sulfate-polyacrylamide gel electrophoresis of extracts of cells of the three strains, a heavy Coomassie-blue stained line was seen, indicating the presence of a protein subunit of molecular weight slightly above 14,400. By immunoblotting with absorbed antiserum, it was shown that this protein was the same as that detected by crossed immunoelectrophoresis. Protease from Streptomyces griseus, but not trypsin, digested the protein. Heating to 100 degrees C did not affect it. By immunoelectron microscopy of embedded and sectioned bacteria that had first been treated with specific antisera and ferritin-labeled antirabbit immunoglobulin, the protein adhesin-antibody complex was found to surround the bacteria as a heavy capsule. After negative staining with uranylacetate (pH approximately 4), the capsule appeared as a mesh of very fine filaments. The possible role of this capsule in the pathogenesis of disease is discussed. Images PMID:2856913

  7. Biomimetic Adhesive Polymers Based on Mussel Adhesive Proteins

    Microsoft Academic Search

    BRUCE P. LEE; JEFFREY L. DALSIN; PHILLIP B. MESSERSMITH

    Nature provides many outstanding examples of adhesive strategies from which chemists and material scientists can draw inspiration in their pursuit of new adhesive materials. As described in other chapters of this book, detailed studies of the adhesive mechanisms of geckos, mussels and other organisms during the past several decades have enhanced our understanding of the underlying physicochemical principles to the

  8. Effects of Surface Properties on Adhesion of Protein to Biomaterials 

    E-print Network

    Feng, Fangzhou

    2011-10-21

    This thesis research investigates the adhesion mechanisms of protein molecules to surfaces of biomaterials. New understanding in such adhesion mechanisms will lead to materials design and surface engineering in order to extend the lifespan...

  9. Aberrant methylation accounts for cell adhesion-related gene silencing during 3-methylcholanthrene and diethylnitrosamine induced multistep rat lung carcinogenesis associated with overexpression of DNA methyltransferases 1 and 3a

    SciTech Connect

    Liu Wenbin; Cui Zhihong; Ao Lin; Zhou Ziyuan; Zhou Yanhong; Yuan Xiaoyan; Xiang Yunlong; Liu Jinyi, E-mail: jinyiliutmmu@163.com; Cao Jia, E-mail: caojia1962@126.com

    2011-02-15

    To evaluate the significance of alterations in cell adhesion-related genes methylation during lung multistep carcinogenesis induced by the genotoxic carcinogens 3-methylcholanthrene (MCA) and diethylnitrosamine (DEN), tissue samples microdissected from MCA/DEN-induced rat lung carcinogenesis model were subjected to methylation-specific PCR to evaluate the DNA methylation status of CADM1, TIMP3, E-cadherin and N-cadherin. Immunohistochemistry was used to determine protein expression of CADM1, TIMP3, N-cadherin and the DNA methyltransferases (DNMTs) 1, 3a and 3b. E-cadherin hypermethylation was not detected in any tissue. CADM1, TIMP3 and N-cadherin hypermethylation was correlated with the loss of their protein expression during the progression of pathologic lesions. The prevalence of DNA methylation of at least one gene and the average number of methylated genes increased with the histological progression. DNMT1 and DNMT3a protein expression increased progressively during the stages of lung carcinogenesis, whereas DNMT3b overexpression was only found in several samples. Furthermore, DNMT1 protein expression levels were correlated with CADM1 methylation, and DNMT3a protein expression levels were correlated with CADM1, TIMP3 and N-cadherin methylation. The average number of methylated genes during carcinogenesis was significantly correlated with DNMT1 and DNMT3a protein expression levels. Moreover, mRNA expression of CADM1 significantly increased after treatment with DNMT inhibitor 5-aza-2'-deoxycytidine in CADM1-methylated primary tumor cell lines. Our findings suggest that an accumulation of hypermethylation accounts for cell adhesion-related gene silencing is associated with dynamic changes in the progression of MCA/DEN-induced rat lung carcinogenesis. We suggest that DNMT1 and DNMT3a protein overexpression may be responsible for this aberrant DNA methylation.

  10. Polymer adhesion at surfaces: biological adhesive proteins and their synthetic mimics

    Microsoft Academic Search

    Phillip Messersmith

    2008-01-01

    Mussels are famous for their ability to permanently adhere to a wide variety of wet surfaces, such as rocks, metal and polymer ship hulls, and wood structures. They accomplish this through specialized proteins collectively referred to as mussel adhesive proteins (MAPs). The biophysical aspects of MAP adhesion is being revealed through the use of single molecule force measurements. The results

  11. Protein conformation as a regulator of cell-matrix adhesion.

    PubMed

    Hytönen, Vesa P; Wehrle-Haller, Bernhard

    2014-04-14

    The dynamic regulation of cell-matrix adhesion is essential for tissue homeostasis and architecture, and thus numerous pathologies are linked to altered cell-extracellular matrix (ECM) interaction and ECM scaffold. The molecular machinery involved in cell-matrix adhesion is complex and involves both sensory and matrix-remodelling functions. In this review, we focus on how protein conformation controls the organization and dynamics of cell-matrix adhesion. The conformational changes in various adhesion machinery components are described, including examples from ECM as well as cytoplasmic proteins. The discussed mechanisms involved in the regulation of protein conformation include mechanical stress, post-translational modifications and allosteric ligand-binding. We emphasize the potential role of intrinsically disordered protein regions in these processes and discuss the role of protein networks and co-operative protein interactions in the formation and consolidation of cell-matrix adhesion and extracellular scaffolds. PMID:24469063

  12. N-cadherin{sup +} HSCs in fetal liver exhibit higher long-term bone marrow reconstitution activity than N-cadherin{sup -} HSCs

    SciTech Connect

    Toyama, Hirofumi; Arai, Fumio; Hosokawa, Kentaro; Ikushima, Yoshiko Matsumoto [Department of Cell Differentiation, The Sakaguchi Laboratory of Developmental Biology, School of Medicine, Keio University, 35 Shinano-machi, Shinjuku-ku, Tokyo 160-8582 (Japan)] [Department of Cell Differentiation, The Sakaguchi Laboratory of Developmental Biology, School of Medicine, Keio University, 35 Shinano-machi, Shinjuku-ku, Tokyo 160-8582 (Japan); Suda, Toshio, E-mail: sudato@z3.keio.jp [Department of Cell Differentiation, The Sakaguchi Laboratory of Developmental Biology, School of Medicine, Keio University, 35 Shinano-machi, Shinjuku-ku, Tokyo 160-8582 (Japan)] [Department of Cell Differentiation, The Sakaguchi Laboratory of Developmental Biology, School of Medicine, Keio University, 35 Shinano-machi, Shinjuku-ku, Tokyo 160-8582 (Japan)

    2012-11-23

    Highlights: Black-Right-Pointing-Pointer High N-cad expression was detected in E12.5 mouse FL LT-HSCs (EPCR{sup +} LSK cells). Black-Right-Pointing-Pointer Immunohistochemically, N-cad{sup +} HSCs co-localized with sinusoidal ECs (Lyve-1{sup +} cells) in E12.5 FL, but these gradually detached in E15.5 and E18.5 FL. Black-Right-Pointing-Pointer N-cad{sup +} LSK cells in E12.5 FL exhibited higher LTR activity versus N-cad{sup -} LSK cells, which decreased in E15.5 and E18.5. Black-Right-Pointing-Pointer N-cad expression may confer high LTR activity to HSCs by facilitating interactions with the perisinusoidal niche in FL. -- Abstract: Adult hematopoietic stem cells (HSCs) are maintained in a microenvironment known as the stem cell niche. The regulation of HSCs in fetal liver (FL) and their niche, however, remains to be elucidated. In this study, we investigated the role of N-cadherin (N-cad) in the maintenance of HSCs during FL hematopoiesis. By using anti-N-cad antibodies (Abs) produced by our laboratory, we detected high N-cad expression in embryonic day 12.5 (E12.5) mouse FL HSCs, but not in E15.5 and E18.5 FL. Immunofluorescence staining revealed that N-cad{sup +}c-Kit{sup +} and N-cad{sup +} endothelial protein C receptor (EPCR){sup +} HSCs co-localized with Lyve-1{sup +} sinusoidal endothelial cells (ECs) in E12.5 FL and that some of these cells also expressed N-cad. However, N-cad{sup +} HSCs were also observed to detach from the perisinusoidal niche at E15.5 and E18.5, concomitant with a down-regulation of N-cad and an up-regulation of E-cadherin (E-cad) in hepatic cells. Moreover, EPCR{sup +} long-term (LT)-HSCs were enriched in the N-cad{sup +}Lin{sup -}Sca-1{sup +}c-Kit{sup +} (LSK) fraction in E12.5 FL, but not in E15.5 or E18.5 FL. In a long-term reconstitution (LTR) activity assay, higher engraftment associated with N-cad{sup +} LSK cells versus N-cad{sup -} LSK cells in E12.5 FL when transplanted into lethally irradiated recipient mice. However, the higher engraftment of N-cad{sup +} LSK cells decreased subsequently in E15.5 and E18.5 FL. It is possible that N-cad expression conferred higher LTR activity to HSCs by facilitating interactions with the perisinusoidal niche, especially at E12.5. The down-regulation of N-cad during FL hematopoiesis may help us better understand the regulation and mobility of HSCs before migration into BM.

  13. ADAM10 mediates N-cadherin ectodomain shedding during retinal ganglion cell differentiation in primary cultured retinal cells from the developing chick retina.

    PubMed

    Paudel, Sharada; Kim, Yeoun-Hee; Huh, Man-Il; Kim, Song-Ja; Chang, Yongmin; Park, Young Jeung; Lee, Kyoo Won; Jung, Jae-Chang

    2013-04-01

    Here, we examined the role of ADAM10 during retinal cell differentiation in retinal sections and in vitro cultures of developing chick retinal cells from embryonic day 6 (ED6). Immunohistochemistry showed that ADAM10 is abundantly expressed in the inner zone of neuroblastic layer at ED5, and it becomes more highly expressed in the ganglion cell layer at ED7 and ED9. Western blotting confirmed that ADAM10 was expressed as an inactive pro-form that was processed to a shorter, active form in control cultured cells, but in cultures treated with an ADAM10 inhibitor (GI254023X) and ADAM10-specific siRNA, the level of mature ADAM10 decreased. Phase-contrast microscopy showed that long neurite extensions were present in untreated cultures 24?h after plating, whereas cultures treated with GI254023X showed significant decreases in neurite extension. Immunofluorescence staining revealed that there were far fewer differentiated ganglion cells in ADAM10 siRNA and GI254023X-treated cultures compared to controls, whereas the photoreceptor cells were unaltered. The Pax6 protein was more strongly detected in the differentiated ganglion cells of control cultures compared to ADAM10 siRNA and GI254023X-treated cultures. N-cadherin ectodomain shedding was apparent in control cultures after 24 h, when ganglion cell differentiation was observed, but ADAM10 siRNA and GI254023X treatment inhibited these processes. In contrast, N-cadherin staining was strongly detected in photoreceptor cells regardless of ADAM10 siRNA and GI254023X treatment. Taken together, these data indicate that the inhibition of ADAM10 can inhibit Pax6 expression and N-cadherin ectodomain shedding in retinal cells, possibly affecting neurite outgrowth and ganglion cell differentiation. PMID:23129104

  14. N-Cadherin is expressed on human hematopoietic progenitor cells and mediates interaction with human mesenchymal stromal cells

    Microsoft Academic Search

    Frederik Wein; Larissa Pietsch; Rainer Saffrich; Patrick Wuchter; Thomas Walenda; Simone Bork; Patrick Horn; Anke Diehlmann; Volker Eckstein; Anthony D. Ho; Wolfgang Wagner

    2010-01-01

    Specific cell–cell junctions between hematopoietic stem cells (HSC) and their niche have been shown to regulate stem cell function. N-cadherin was suggested to play a central role in this process, whereas other studies indicated that it did not play an essential role in the murine model. We have analyzed the role of N-cadherin for interaction between hematopoietic progenitor cells (HPC)

  15. Vascular Adhesion Protein 1 in the Eye

    PubMed Central

    Luo, Wenting; Xie, Fang; Zhang, Zhongyu; Sun, Dawei

    2013-01-01

    Semicarbazide-sensitive amine oxidase/vascular adhesion protein-1 (SSAO/VAP-1), a dual-function molecule with adhesive and enzymatic properties, is expressed on the surface of vascular endothelial cells of mammals. It also exists as a soluble form (sVAP-1), which is implicated in oxidative stress via its enzymatic activity and can be a prognostic biomarker. Recent evidence suggests that VAP-1 is an important therapeutic target for several inflammation-related ocular diseases, such as uveitis, age-related macular degeneration (AMD), and diabetic retinopathy (DR), by involving in the recruitment of leukocytes at sites of inflammation. Furthermore, VAP-1 plays an important role in the pathogenesis of conjunctival inflammatory diseases such as pyogenic granulomas and the progression of conjunctival lymphoma. VAP-1 may be an alternative therapeutic target in ocular diseases. The in vivo imaging of inflammation using VAP-1 as a target molecule is a novel approach with a potential for early detection and characterization of inflammatory diseases. This paper reviews the critical roles of VAP-1 in ophthalmological diseases which may provide a novel research direction or a potent therapeutic strategy. PMID:23840939

  16. Biomimetic soy protein nanocomposites with calcium carbonate crystalline arrays for use as wood adhesive

    E-print Network

    and bonding strength of soy protein adhesives. Glue strength of soy protein hybrid adhesive was higher than 6 2010 Available online 21 March 2010 Keywords: Wood glue Calcium carbonate Gecko adhesion Soy protein the adhesion strength. The structure and morphology of the adhesive and its fracture bonding interface

  17. Cloning and expression studies of cDNA for a novel Xenopus cadherin (XmN-cadherin), expressed maternally and later neural-specifically in embryogenesis

    Microsoft Academic Search

    Kosuke Tashiro; Osamu Tooi; Hisashi Nakamura; Chie Koga; Yuzuru Ito; Hiroki Hikasa; Koichiro Shiokawa

    1996-01-01

    From aXenopus tailbud cDNA library, we obtained the cDNA for a novel cadherin which was named as XmN-cadherin (Xenopus maternally expressed neural cadherin). The cDNA consisted of 3690 bp and encoded 922 amino acid residues. XmN-cadherin preserved five extracellular cadherin motifs, a single transmembrane domain, and a cytoplasmic domain, and was closely related by its sequence to R- and N-cadherin.

  18. An isoform-specific allele of Drosophila N-cadherin disrupts a late step of R7 targeting

    PubMed Central

    Nern, Aljoscha; Nguyen, Louis-Vu T.; Herman, Tory; Prakash, Saurabh; Clandinin, Thomas R.; Zipursky, S. Lawrence

    2005-01-01

    Drosophila N-cadherin is required for the formation of precise patterns of connections in the fly brain. Alternative splicing is predicted to give rise to 12 N-cadherin isoforms. We identified an N-cadherin allele, N-cad18Astop, that eliminates the six isoforms containing alternative exon 18A and demonstrate that it strongly disrupts the connections of R7 photoreceptor neurons. During the first half of pupal development, N-cadherin is required for R7 growth cones to terminate within a temporary target layer in the medulla. N-cadherin isoforms containing exon 18B are sufficient for this initial targeting. By contrast, 18A isoforms are preferentially expressed in R7 during the second half of pupal development and are necessary for R7 to terminate in the appropriate synaptic layer in the medulla neuropil. Transgene rescue experiments suggest that differences in isoform expression, rather than biochemical differences between isoforms, underlie the 18A isoform requirement in R7 neurons. PMID:16123134

  19. ADAM9 Up-Regulates N-Cadherin via miR-218 Suppression in Lung Adenocarcinoma Cells

    PubMed Central

    Sher, Yuh-Pyng; Wang, Li-Ju; Chuang, Li-Ling; Tsai, Mong-Hsun; Kuo, Ting-Ting; Huang, Cheng-Chung; Chuang, Eric Y.; Lai, Liang-Chuan

    2014-01-01

    Lung cancer is the leading cause of cancer death worldwide, and brain metastasis is a major cause of morbidity and mortality in lung cancer. CDH2 (N-cadherin, a mesenchymal marker of the epithelial-mesenchymal transition) and ADAM9 (a type I transmembrane protein) are related to lung cancer brain metastasis; however, it is unclear how they interact to mediate this metastasis. Because microRNAs regulate many biological functions and disease processes (e.g., cancer) by down-regulating their target genes, microRNA microarrays were used to identify ADAM9-regulated miRNAs that target CDH2 in aggressive lung cancer cells. Luciferase assays and western blot analysis showed that CDH2 is a target gene of miR-218. MiR-218 was generated from pri-mir-218-1, which is located in SLIT2, in non-invasive lung adenocarcinoma cells, whereas its expression was inhibited in aggressive lung adenocarcinoma. The down-regulation of ADAM9 up-regulated SLIT2 and miR-218, thus down-regulating CDH2 expression. This study revealed that ADAM9 activates CDH2 through the release of miR-218 inhibition on CDH2 in lung adenocarcinoma. PMID:24705471

  20. Cranial sensory ganglia neurons require intrinsic N-cadherin function for guidance of afferent fibers to their final targets

    PubMed Central

    LaMora, Angela; Voigt, Mark M.

    2009-01-01

    Cell adhesion molecules, such as N-cadherin (cdh2), are essential for normal neuronal development, and as such have been implicated in an array of processes including neuronal differentiation and migration, and axon growth and fasciculation. Cdh2 is expressed in neurons of the peripheral nervous system during development, but its role in these cells during this time is poorly understood. Using the transgenic zebrafish line, tg(p2xr3.2:eGFPsl1), we have examined the involvement of cdh2 in the formation of sensory circuits by the peripheral nervous system. The tg(p2xr3.2:eGFPsl1) fish allows visualization of neurons comprising gV, gVII, gIX and gX and their axons throughout development. Reduction of cdh2 in this line was achieved by either crosses to the cdh2-mutant strain, glass onion (glo) or injection of a cdh2 morpholino (MO) into single-cell embryos. Here we show that cdh2 function is required to alter the directional vectors of growing axons upon reaching intermediate targets. The central axons enter the hindbrain appropriately but fail to turn caudally towards their final targets. Similarly, the peripheral axons extend ventrally, but fail to turn and project along a rostral/caudal axis. Furthermore, by expressing dominant negative cdh2 constructs selectively within cranial sensory ganglia (CSG) neurons, we found that cdh2 function is necessary within the axons to elicit these stereotypic turns, thus demonstrating that cdh2 acts cell autonomously. Together, our in vivo data reveal a novel role for cdh2 in the establishment of circuits by peripheral sensory neurons. PMID:19356698

  1. Vascular adhesion protein-1 (VAP-1)

    Microsoft Academic Search

    Marko Salmi; Sirpa Jalkanen

    In 1980s the leukocyte adhesion molecules and their ligands on the vascular endothelium were thought to explain tissue-selective,\\u000a or even tissue-specific, leukocyte traffic. At the same time it became apparent that vessels in inflamed joints displayed\\u000a binding characteristics clearly distinct from those in peripheral lymph nodes, gut and skin. In search of joint-selective\\u000a endothelial adhesion molecules we therefore isolated vascular

  2. Adhesive Dynamics Simulation of G-Protein-Mediated Chemokine-Activated Neutrophil Adhesion

    PubMed Central

    Caputo, Kelly E.; Hammer, Daniel A.

    2009-01-01

    Abstract To reach sites of inflammation, a blood-borne neutrophil first rolls over the vessel wall, becoming firmly adherent on activation, and then transmigrates through the endothelium. In this study, we simulate the transition to firm adhesion via chemokine-induced integrin activation. To recreate the transition from rolling to firm adhesion, we use an integrated signaling adhesive dynamics simulation that includes selectin, integrin, and chemokine interactions between the cell and an adhesive substrate. Integrin bonds are of low affinity until activated by chemokine binding to G-protein coupled receptors on the model cell. The signal propagates within the cell through probabilistic diffusion and reaction of the signaling elements to induce the high-affinity integrins required for firm adhesion. This model showed that integrins become progressively active as cells roll and interact with chemokines, leading to a slight slowing before firm adhesion on a timescale similar to that observed in experiments. Increasing the density of chemokine resulted in decreases in the rolling time before stopping, consistent with experimental observations. However, a limit is reached where further increases in chemokine density do not increase adhesion. We found that the timescale for integrin activation correlated with the time to stop. Further, altering parameters within the intracellular signaling cascade that changed the speed of integrin activation, such as effector activation and dissociation rates, correspondingly affected the time to firm adhesion. For all conditions tested, the number of active integrin bonds at the point of firm adhesion was relatively constant. The model predicts that the time to stop would be relatively independent of selectin or integrin density, but strongly dependent on the shear rate because higher shear rates limit the intrinsic activation rate of integrins and require more integrins for adhesion. PMID:19383446

  3. Unfolding individual Als5p adhesion proteins on live cells

    PubMed Central

    Alsteens, David; Dupres, Vincent; Klotz, Stephen A.; Gaur, Nand K.; Lipke, Peter N.; Dufrêne, Yves F.

    2009-01-01

    Elucidating the molecular mechanisms behind the strength and mechanics of cell adhesion proteins is of central importance in cell biology, and offers exciting avenues for the identification of potential drug targets. Here we use single-molecule force spectroscopy to investigate the adhesive and mechanical properties of the widely expressed Als5p cell adhesion protein from the opportunistic pathogen Candida albicans. We show that the forces required to unfold individual tandem repeats of the protein are in the 150–250 pN range, both on isolated molecules and on live cells. We also find that the unfolding probability increases with the number of tandem repeats and correlates with the level of cell adherence. We suggest that the modular and flexible nature of Als5p conveys both strength and toughness to the protein, making it ideally-suited for cell adhesion. The single molecule measurements presented here open new avenues for understanding the mechanical properties of adhesion molecules from mammalian and microbial cells, and may help us to elucidate their potential implications in diseases like inflammation, cancer and infection. PMID:19534503

  4. Expression of Functional Recombinant Mussel Adhesive Protein Mgfp-5 in Escherichia coli

    Microsoft Academic Search

    Dong Soo Hwang; Hyo Jin Yoo; Jong Hyub Jun; Won Kyu Moon; Hyung Joon Cha

    2004-01-01

    Mussel adhesive proteins have been suggested as a basis for environmentally friendly adhesives for use in aqueous conditions and in medicine. However, attempts to produce functional and economical recombinant mussel adhesive proteins (mainly foot protein type 1) in several systems have failed. Here, the cDNA coding for Mytilus galloprovincialis foot protein type 5 (Mgfp-5) was isolated for the first time.

  5. Hexavalent chromium at low concentration alters Sertoli cell barrier and connexin 43 gap junction but not claudin-11 and N-cadherin in the rat seminiferous tubule culture model

    SciTech Connect

    Carette, Diane [INSERM U 1065, Team 5 “Physiopathology of Germ Cell Control: Genomic and Non Genomic Mechanisms” C3M, University of Nice Sophia Antipolis, Nice (France); UMR S775, University Paris Descartes, 45 rue des Saints Pères, 75006, Paris (France); Perrard, Marie-Hélène, E-mail: marie-helene.durand@ens-lyon.fr [Institut de Génomique Fonctionnelle de Lyon, Université de Lyon, Université Lyon I, CNRS, INRA, Ecole Normale Supérieure de Lyon, Lyon (France); Prisant, Nadia [University of Versailles/St Quentin-en-Yvelines (France); UMR S775, University Paris Descartes, 45 rue des Saints Pères, 75006, Paris (France); Gilleron, Jérome; Pointis, Georges [INSERM U 1065, Team 5 “Physiopathology of Germ Cell Control: Genomic and Non Genomic Mechanisms” C3M, University of Nice Sophia Antipolis, Nice (France); Segretain, Dominique [University of Versailles/St Quentin-en-Yvelines (France); UMR S775, University Paris Descartes, 45 rue des Saints Pères, 75006, Paris (France); Durand, Philippe [Institut de Génomique Fonctionnelle de Lyon, Université de Lyon, Université Lyon I, CNRS, INRA, Ecole Normale Supérieure de Lyon, Lyon (France); Kallistem SAS Ecole Normale Supérieure de Lyon, Lyon (France)

    2013-04-01

    Exposure to toxic metals, specifically those belonging to the nonessential group leads to human health defects and among them reprotoxic effects. The mechanisms by which these metals produce their negative effects on spermatogenesis have not been fully elucidated. By using the Durand's validated seminiferous tubule culture model, which mimics the in vivo situation, we recently reported that concentrations of hexavalent chromium, reported in the literature to be closed to that found in the blood circulation of men, increase the number of germ cell cytogenetic abnormalities. Since this metal is also known to affect cellular junctions, we investigated, in the present study, its potential influence on the Sertoli cell barrier and on junctional proteins present at this level such as connexin 43, claudin-11 and N-cadherin. Cultured seminiferous tubules in bicameral chambers expressed the three junctional proteins and ZO-1 for at least 12 days. Exposure to low concentrations of chromium (10 ?g/l) increased the trans-epithelial resistance without major changes of claudin-11 and N-cadherin expressions but strongly delocalized the gap junction protein connexin 43 from the membrane to the cytoplasm of Sertoli cells. The possibility that the hexavalent chromium-induced alteration of connexin 43 indirectly mediates the effect of the toxic metal on the blood–testis barrier dynamic is postulated. - Highlights: ? Influence of Cr(VI) on the Sertoli cell barrier and on junctional proteins ? Use of cultured seminiferous tubules in bicameral chambers ? Low concentrations of Cr(VI) (10 ?g/l) altered the trans-epithelial resistance. ? Cr(VI) did not alter claudin-11 and N-cadherin. ? Cr(VI) delocalized connexin 43 from the membrane to the cytoplasm of Sertoli cells.

  6. Hydrophobicity, Adhesion, and Surface-Exposed Proteins of Gliding Bacteria

    PubMed Central

    Sorongon, Maria L.; Bloodgood, Robert A.; Burchard, Robert P.

    1991-01-01

    The cell surface hydrophobicities of a variety of aquatic and terrestrial gliding bacteria were measured by an assay of bacterial adherence to hydrocarbons (BATH), hydrophobic interaction chromatography, and the salt aggregation test. The bacteria demonstrated a broad range of hydrophobicities. Results among the three hydrophobicity assays performed on very hydrophilic strains were quite consistent. Bacterial adhesion to glass did not correlate with any particular measure of surface hydrophobicity. Several adhesion-defective mutants of Cytophaga sp. strain U67 were found to be more hydrophilic than the wild type, particularly by the BATH assay and hydrophobic interaction chromatography. The very limited adhesion of these mutants correlated well with hydrophilicity as determined by the BATH assay. The hydrophobicities of several adhesion-competent revertants ranged between those of the wild type and the mutants. As measured by the BATH assay, starvation increased hydrophobicity of both the wild type and an adhesion-defective mutant. During filament fragmentation of Flexibacter sp. strain FS-1, marked changes in hydrophobicity and adhesion were accompanied by changes in the arrays of surface-exposed proteins as detected by an immobilized radioiodination procedure. Images PMID:16348583

  7. Comparison of protein-based adhesive resins for wood composites

    Microsoft Academic Search

    In Yang; Monlin Kuo; Deland J. Myers; Anbin Pu

    2006-01-01

    The search for new value-added uses for oilseed and animal proteins led us to develop protein-based wood adhesives. Low-fat\\u000a soy and peanut flours and blood meal were hydrolyzed in an alkaline state, and PF-cross-linked protein resins were formulated\\u000a by reacting the protein hydrolyzates with phenol-formaldehyde (PF) in solid-tosolid ratios ranging from 70% to 50% hydrolyzates\\u000a and 30% to 50% PF.

  8. Polymeric Thin Films That Resist the Adsorption of Proteins and the Adhesion of Bacteria

    E-print Network

    Prentiss, Mara

    Polymeric Thin Films That Resist the Adsorption of Proteins and the Adhesion of Bacteria Robert G of thin polymeric films that resist the adsorption of proteins and the adhesion of bacteria to an extent.Polyaminesfunctionalizedwithacetylchlorideproducedfilmsthatresistedtheadsorption of protein and the adhesion of bacteria to a useful extent. Functionalization of the polyamine with acyl

  9. Protein kinase C activation stimulates mesenchymal stem cell adhesion through activation of focal adhesion kinase.

    PubMed

    Song, Byeong-Wook; Chang, Woochul; Hong, Bum-Kee; Kim, Il-Kwon; Cha, Min-Ji; Lim, Soyeon; Choi, Eun Ju; Ham, Onju; Lee, Se-Yeon; Lee, Chang Youn; Park, Jun-Hee; Choi, Eunmi; Song, Heesang; Jang, Yangsoo; Hwang, Ki-Chul

    2013-01-01

    Emerging evidence suggests that cell therapy with mesenchymal stem cells (MSCs) has beneficial effects on the injured heart. However, the decreased survival and/or adhesion of MSCs under ischemic conditions limits the application of cell transplantation as a therapeutic modality. We investigated a potential method of increasing the adhesion ability of MSCs to improve their efficacy in the ischemic heart. Treatment of MSCs with PKC activator, phorbol 12-myristate 13-acetate (PMA), increased cell adhesion and spreading in a dose-dependent method and significantly decreased detachment. When MSCs were treated with PKC inhibitor, that is, rottlerin, adhesion of MSCs was slightly diminished, and detachment was also decreased compared to the treatment with PMA. MSCs treated with both PMA and rottlerin behaved similarly to normal controls. In 3D matrix cardio gel, treatment with PMA increased the number of MSCs compared to the control group and MSCs treated with rottlerin. Expressions of focal adhesion kinase, cytoskeleton-associated proteins, and integrin subunits were clearly demonstrated in PMA-treated MSCs by immunoblotting and/or immunocytochemistry. The effect of PKC activator treatment on MSCs was validated in vivo. Following injection into rat hearts, the PMA-treated MSCs exhibited significantly higher retention in infarcted myocardium compared to the MSC group. Infarct size, fibrosis area, and apoptotic cells were reduced, and cardiac function was improved in rat hearts injected with PMA-treated MSCs compared to sham and/or MSC-implanted group. These results indicate that PKC activator is a potential target for niche manipulation to enhance adhesion of MSCs for cardiac regeneration. PMID:23006313

  10. Cortical neural precursors inhibit their own differentiation via N-cadherin maintenance of beta-catenin signaling

    PubMed Central

    Zhang, Jianing; Woodhead, Gregory J; Swaminathan, Sruthi K; Noles, Stephanie R; McQuinn, Erin R; Pisarek, Anna J; Stocker, Adam M; Mutch, Christopher A; Funatsu, Nobuo; Chenn, Anjen

    2010-01-01

    Little is known about the architecture of cellular microenvironments that support stem and precursor cells during tissue development. Although adult stem cell niches are organized by specialized supporting cells, in the developing cerebral cortex, neural stem/precursor cells reside in a neurogenic niche lacking distinct supporting cells. Here we find that neural precursors themselves comprise the niche and regulate their own development. Precursor-precursor contact regulates ?-catenin signaling and cell fate. In vivo knockdown of N-cadherin reduces ?-catenin signaling, migration from the niche and neuronal differentiation in vivo. N-cadherin engagement activates ?-catenin signaling via Akt, suggesting a mechanism through which cells in tissues can regulate their development. These results suggest that neural precursor cell interactions can generate a self-supportive niche to regulate their own number. PMID:20230753

  11. Cloning and expression of cDNA encoding a neural calcium-dependent cell adhesion molecule: its identity in the cadherin gene family

    Microsoft Academic Search

    Kohei Hatta; Akinao Nose; Akira Nagafuchi; Masatoshi Takeichi

    1988-01-01

    The neural cadherin (N-cadherin) is a Ca 2+- dependent cell-cell adhesion molecule detected in neu- ral tissues as well as in non-neural tissues. We report here the nucleotide sequence of the chicken N-cad- herin cDNA and the deduced amino acid sequence. The sequence data suggest that N-cadherin has one transmembrane domain which divides the molecule into an extracellular and a

  12. Novel hydrogel actuator inspired by reversible mussel adhesive protein chemistry.

    PubMed

    Lee, Bruce P; Konst, Shari

    2014-06-01

    A novel hydrogel actuator that combines ionoprinting techniques with reversible catechol-metal ion coordination chemistry found in mussel adhesive proteins is developed. Deposited metal ions increase the local crosslinking density, which induces sharp bending of the hydrogel. Reversibly bound metal ions can be removed and reintroduced in a different pattern so that the hydrogel can be reprogrammed to transform into a different 3-dimentional shape. PMID:24596273

  13. Evaluation of photodynamic therapy in adhesion protein expression

    PubMed Central

    PACHECO-SOARES, CRISTINA; MAFTOU-COSTA, MAIRA; DA CUNHA MENEZES COSTA, CAROLINA GENÚNCIO; DE SIQUEIRA SILVA, ANDREZA CRISTINA; MORAES, KAREN C.M.

    2014-01-01

    Photodynamic therapy (PDT) is a treatment modality that has clinical applications in both non-neoplastic and neoplastic diseases. PDT involves a light-sensitive compound (photosensitizer), light and molecular oxygen. This procedure may lead to several different cellular responses, including cell death. Alterations in the attachment of cancer cells to the substratum and to each other are important consequences of photodynamic treatment. PDT may lead to changes in the expression of cellular adhesion structure and cytoskeleton integrity, which are key factors in decreasing tumor metastatic potential. HEp-2 cells were photosensitized with aluminum phthalocyanine tetrasulfonate and zinc phthalocyanine, and the proteins ?1-integrin and focal adhesion kinase (FAK) were assayed using fluorescence microscopy. The verification of expression changes in the genes for FAK and ?1 integrin were performed by reverse transcription-polymerase chain reaction (RT-PCR). The results revealed that HEp-2 cells do not express ?-integrin or FAK 12 h following PDT. It was concluded that the PDT reduces the adhesive ability of HEp-2 cells, inhibiting their metastatic potential. The present study aimed to analyze the changes in the expression and organization of cellular adhesion elements and the subsequent metastatic potential of HEp-2 cells following PDT treatment. PMID:25013490

  14. Isolation of Focal Adhesion Proteins for Biochemical and Proteomic Analysis

    PubMed Central

    Kuo, Jean-Cheng; Han, Xuemei; Yates, John R.; Waterman, Clare M.

    2014-01-01

    Focal adhesions (FAs) are discrete plasma membrane-associated adhesive organelles that play dual roles in cell force transduction and signaling. FAs consist of clustered transmembrane heterodimeric integrin extracellular matrix (ECM) receptors and a large number of cytoplasmic proteins that collectively form thin plaques linking the ECM to actin filament bundles of the cytoskeleton. FAs are complex organelles that can change their composition in response to biochemical or mechanical cues. These compositional differences may underlie the ability of FAs to mediate an array of important cell functions including adhesion, signaling, force transduction, and regulation of the cytoskeleton. These functions contribute to the physiological processes of the immune response, development, and differentiation. However, linking FA composition to FA function has been difficult since there has been no method to isolate intact FAs reproducibly and determine their composition. We report here a new method for isolating FA structures in cultured cells distinct from cytoplasmic, nuclear, and internal membranous organellar components of the cell. We provide protocols for validation of the fractionation by immunofluorescence and immunoblotting, procedures for preparing the isolated FAs for mass spectrometric proteomic analysis, tips on data interpretation and analysis, and an approach for comparing FA composition in cells in which small GTPase signaling is perturbed. PMID:21909920

  15. Small heat shock proteins in cellular adhesion and migration

    PubMed Central

    Montagna, Georgina N.; Matuschewski, Kai; Buscaglia, Carlos A.

    2012-01-01

    Cellular locomotion and adhesion critically depend on regulated turnover of filamentous actin. Biochemical data from diverse model systems support a role for the family of small heat shock proteins (HSPBs) in microfilament regulation. The small chaperones could either act directly, through competition with the motor myosin, or indirectly, through modulation of actin depolymerizing factor/cofilin activity. However, a direct link between HSPBs and actin-based cellular motility remained to be established. In a recent experimental genetics study, we provided evidence for regulation of Plasmodium motility by HSPB6/Hsp20. The infectious forms of malaria parasites, termed sporozoites, display fast and continuous substrate-dependent motility, which is largely driven by turnover of actin microfilaments. Sporozoite gliding locomotion is essential to avoid destruction by host defense mechanisms and to ultimately reach a hepatocyte, the target cell, where to transform and replicate. Genetic ablation of Plasmodium HSP20 dramatically changed sporozoite speed and substrate adhesion, resulting in impaired natural malaria transmission. In this article, we discuss the function of Hsp20 in this fast-moving unicellular protozoan and implications for the roles of HSPBs in adhesion and migration of eukaryotic cells. PMID:22568951

  16. Adhesion and structure properties of protein nanomaterials containing hydrophobic and charged amino acids.

    PubMed

    Shen, Xinchun; Mo, Xiaoqun; Moore, Robyn; Frazier, Shawnalea J; Iwamoto, Takeo; Tomich, John M; Sun, Xiuzhi Susan

    2006-03-01

    Protein polymers are being used or considered for biobased adhesives and coating materials. Most adhesives derived from macro protein molecules work through receptors or cross-links to bring about adhesion. The adhesion mechanism of protein polymers would lead to better understanding of adhesives and the discovery of new practical properties of protein polymers at both nano- and macro-scales. The objective of this research work was to study adhesion properties of protein polymers at nanoscale (a peptide adhesive with nanometer-scale units that range in size of several nanometers, defined as protein nanomaterial). Seven protein nanomaterial samples with different degrees of adhesive strength were designed and synthesized using solid phase chemistries. All protein nanomaterials contain a common hydrophobic core flanked by charged amino acid sequences. The adhesion properties of the protein nanomaterials were investigated at different pH values and curing temperatures. The protein nanomaterials self aggregate and interact with the wood surface. The protein nanomaterial KKK-FLIVIGSII-KKK identified in this study had high adhesive strength toward wood. It had the highest shear strength at pH 12, with an amino acid sequence that was very hydrophobic and uncharged. This protein nanomaterial underwent structural analyses using circular dichroism, laser-Fourier transform infrared, and laser desorption mass spectrometry. At pH 12 this peptide adopted a pH-induced beta-like conformation. Adhesive strength reflects contributions of both hydrogen bonding and van der Waals interactions. Ionic and covalent bonds do not appear to be significant factors for adhesion in this study. PMID:16573147

  17. Adhesion Proteins in the Biology of Breast Cancer: Contribution of CD44

    Microsoft Academic Search

    A. Herrera-Gayol; S. Jothy

    1999-01-01

    One of the most important features of tumor cell invasion is the ability to establish or modulate adhesion to other cells or to an extracellular matrix, a process mediated by a large number of adhesion proteins. This review examines how CD44 participates in malignant transformation and progression of the breast epithelium. CD44 is a family of cell adhesion glycoproteins generated

  18. Actopaxin, a new focal adhesion protein that binds paxillin LD motifs and actin and regulates cell adhesion.

    PubMed

    Nikolopoulos, S N; Turner, C E

    2000-12-25

    Paxillin is a focal adhesion adapter protein involved in the integration of growth factor- and adhesion-mediated signal transduction pathways. Paxillin LD motifs have been demonstrated to bind to several proteins associated with remodeling of the actin cytoskeleton including the focal adhesion kinase, vinculin, and a complex of proteins comprising p95PKL, PIX, and PAK (Turner, C.E., M. C. Brown, J.A. Perrotta, M.C. Riedy, S.N. Nikolopoulos, A.R. McDonald, S. Bagrodia, S. Thomas, and P.S. Leventhal. 1999. J. Cell Biol. 145:851-863). In this study, we report the cloning and initial characterization of a new paxillin LD motif-binding protein, actopaxin. Analysis of the deduced amino acid sequence of actopaxin reveals a 42-kD protein with two calponin homology domains and a paxillin-binding subdomain (PBS). Western blotting identifies actopaxin as a widely expressed protein. Actopaxin binds directly to both F-actin and paxillin LD1 and LD4 motifs. It exhibits robust focal adhesion localization in several cultured cell types but is not found along the length of the associated actin-rich stress fibers. Similar to paxillin, it is absent from actin-rich cell-cell adherens junctions. Also, actopaxin colocalizes with paxillin to rudimentary focal complexes at the leading edge of migrating cells. An actopaxin PBS mutant incapable of binding paxillin in vitro cannot target to focal adhesions when expressed in fibroblasts. In addition, ectopic expression of the PBS mutant and/or the COOH terminus of actopaxin in HeLa cells resulted in substantial reduction in adhesion to collagen. Together, these results suggest an important role for actopaxin in integrin-dependent remodeling of the actin cytoskeleton during cell motility and cell adhesion. PMID:11134073

  19. Actopaxin, a New Focal Adhesion Protein That Binds Paxillin Ld Motifs and Actin and Regulates Cell Adhesion

    PubMed Central

    Nikolopoulos, Sotiris N.; Turner, Christopher E.

    2000-01-01

    Paxillin is a focal adhesion adapter protein involved in the integration of growth factor– and adhesion-mediated signal transduction pathways. Paxillin LD motifs have been demonstrated to bind to several proteins associated with remodeling of the actin cytoskeleton including the focal adhesion kinase, vinculin, and a complex of proteins comprising p95PKL, PIX, and PAK (Turner, C.E., M.C. Brown, J.A. Perrotta, M.C. Riedy, S.N. Nikolopoulos, A.R. McDonald, S. Bagrodia, S. Thomas, and P.S. Leventhal. 1999. J. Cell Biol. 145:851–863). In this study, we report the cloning and initial characterization of a new paxillin LD motif–binding protein, actopaxin. Analysis of the deduced amino acid sequence of actopaxin reveals a 42-kD protein with two calponin homology domains and a paxillin-binding subdomain (PBS). Western blotting identifies actopaxin as a widely expressed protein. Actopaxin binds directly to both F-actin and paxillin LD1 and LD4 motifs. It exhibits robust focal adhesion localization in several cultured cell types but is not found along the length of the associated actin-rich stress fibers. Similar to paxillin, it is absent from actin-rich cell–cell adherens junctions. Also, actopaxin colocalizes with paxillin to rudimentary focal complexes at the leading edge of migrating cells. An actopaxin PBS mutant incapable of binding paxillin in vitro cannot target to focal adhesions when expressed in fibroblasts. In addition, ectopic expression of the PBS mutant and/or the COOH terminus of actopaxin in HeLa cells resulted in substantial reduction in adhesion to collagen. Together, these results suggest an important role for actopaxin in integrin-dependent remodeling of the actin cytoskeleton during cell motility and cell adhesion. PMID:11134073

  20. Focal adhesion protein abnormalities in myelodysplastic mesenchymal stromal cells

    SciTech Connect

    Aanei, Carmen Mariana, E-mail: caanei@yahoo.com [Laboratoire Hematologie, CHU de Saint-Etienne, 42055, Saint-Etienne (France); Department of Immunology, Gr. T. Popa University of Medicine and Pharmacy, 700115, Iasi (Romania); Eloae, Florin Zugun [Department of Immunology, Gr. T. Popa University of Medicine and Pharmacy, 700115, Iasi (Romania)] [Department of Immunology, Gr. T. Popa University of Medicine and Pharmacy, 700115, Iasi (Romania); Flandrin-Gresta, Pascale [Laboratoire Hematologie, CHU de Saint-Etienne, 42055, Saint-Etienne (France) [Laboratoire Hematologie, CHU de Saint-Etienne, 42055, Saint-Etienne (France); CNRS UMR 5239, Universite de Lyon, 42023, Saint-Etienne (France); Tavernier, Emmanuelle [Service Hematologie Clinique, Institut de Cancerologie de la Loire, 42270, Saint-Priest-en-Jarez (France) [Service Hematologie Clinique, Institut de Cancerologie de la Loire, 42270, Saint-Priest-en-Jarez (France); CNRS UMR 5239, Universite de Lyon, 42023, Saint-Etienne (France); Carasevici, Eugen [Department of Immunology, Gr. T. Popa University of Medicine and Pharmacy, 700115, Iasi (Romania)] [Department of Immunology, Gr. T. Popa University of Medicine and Pharmacy, 700115, Iasi (Romania); Guyotat, Denis [Service Hematologie Clinique, Institut de Cancerologie de la Loire, 42270, Saint-Priest-en-Jarez (France) [Service Hematologie Clinique, Institut de Cancerologie de la Loire, 42270, Saint-Priest-en-Jarez (France); CNRS UMR 5239, Universite de Lyon, 42023, Saint-Etienne (France); Campos, Lydia [Laboratoire Hematologie, CHU de Saint-Etienne, 42055, Saint-Etienne (France) [Laboratoire Hematologie, CHU de Saint-Etienne, 42055, Saint-Etienne (France); CNRS UMR 5239, Universite de Lyon, 42023, Saint-Etienne (France)

    2011-11-01

    Direct cell-cell contact between haematopoietic progenitor cells (HPCs) and their cellular microenvironment is essential to maintain 'stemness'. In cancer biology, focal adhesion (FA) proteins are involved in survival signal transduction in a wide variety of human tumours. To define the role of FA proteins in the haematopoietic microenvironment of myelodysplastic syndromes (MDS), CD73-positive mesenchymal stromal cells (MSCs) were immunostained for paxillin, pFAK [Y{sup 397}], and HSP90{alpha}/{beta} and p130CAS, and analysed for reactivity, intensity and cellular localisation. Immunofluorescence microscopy allowed us to identify qualitative and quantitative differences, and subcellular localisation analysis revealed that in pathological MSCs, paxillin, pFAK [Y{sup 397}], and HSP90{alpha}/{beta} formed nuclear molecular complexes. Increased expression of paxillin, pFAK [Y{sup 397}], and HSP90{alpha}/{beta} and enhanced nuclear co-localisation of these proteins correlated with a consistent proliferative advantage in MSCs from patients with refractory anaemia with excess blasts (RAEB) and negatively impacted clonogenicity of HPCs. These results suggest that signalling via FA proteins could be implicated in HPC-MSC interactions. Further, because FAK is an HSP90{alpha}/{beta} client protein, these results suggest the utility of HSP90{alpha}/{beta} inhibition as a target for adjuvant therapy for myelodysplasia.

  1. Protein-based underwater adhesives and the prospects for their biotechnological production

    Microsoft Academic Search

    Russell J. Stewart

    2011-01-01

    Biotechnological approaches to practical production of biological protein-based adhesives have had limited success over the\\u000a last several decades. Broader efforts to produce recombinant adhesive proteins may have been limited by early disappointments.\\u000a More recent synthetic polymer approaches have successfully replicated some aspects of natural underwater adhesives. For example,\\u000a synthetic polymers, inspired by mussels, containing the catecholic functional group of 3,4-L-dihydroxyphenylalanine

  2. A new crystal form of human vascular adhesion protein 1

    PubMed Central

    Ernberg, Karin; McGrath, Aaron P.; Peat, Thomas S.; Adams, Timothy E.; Xiao, Xiaowen; Pham, Tam; Newman, Janet; McDonald, Ian A.; Collyer, Charles A.; Guss, J. Mitchell

    2010-01-01

    Human vascular adhesion protein 1 (VAP-1) is involved in lymphocyte–endothelial cell adhesion and has been implicated in many human inflammatory diseases. VAP-1 is a member of the copper amine oxidase family of enzymes with a trihydroxyphenylalanine quinone (TPQ) cofactor. Previously characterized crystals of VAP-1 suffered from anisotropy and contained disordered regions; in addition, one form was consistently twinned. In an effort to grow crystals that diffracted to higher resolution for inhibitor-binding studies, a construct with an N-terminal deletion was made and expressed in the Chinese hamster ovary (CHO) glycosylation mutant cell line Lec8. Screening produced crystals that displayed some anisotropy and contained seven molecules per asymmetric unit. These crystals belonged to space group C2, with unit-cell parameters a = 394.5, b = 115.8, c = 179.3?Å, ? = 112.3°. The structure was refined to a resolution of 2.9?Å, with R cryst and R free values of 0.250 and 0.286, respectively. PMID:21139198

  3. Processing of mussel adhesive protein analog thin films by matrix assisted pulsed laser evaporation

    NASA Astrophysics Data System (ADS)

    Cristescu, R.; Patz, T.; Narayan, R. J.; Menegazzo, N.; Mizaikoff, B.; Mihaiescu, D. E.; Messersmith, P. B.; Stamatin, I.; Mihailescu, I. N.; Chrisey, D. B.

    2005-07-01

    Mussel adhesive proteins are a new class of biologically-derived materials that possess unique biocompatibility, bioactivity, and adhesion properties. We have demonstrated successful thin film growth of 3,4-dihydroxyphenyl- L-alanine modified poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (DOPA modified- PEO-PPO-PEO) block copolymer, a mussel adhesive protein analog, using matrix assisted pulsed laser evaporation. We have demonstrated that the main functional groups of the mussel adhesive protein analog are present in the transferred film. The effect of increasing of chain length of the mussel adhesive protein analog on film structure was also examined. These novel polymer thin films could have numerous medical and technological applications if their thin film properties are similar to what is found in bulk. This is the first report of successful MAPLE deposition of this material as thin films.

  4. N-CADHERIN/P120 CATENIN ASSOCIATION AT CELL-CELL CONTACTS OCCURS IN CHOLESTEROL-RICH MEMBRANE DOMAINS AND IS REQUIRED FOR RHOA

    E-print Network

    Boyer, Edmond

    by diffusible molecules and the interaction of muscle cell precursors with their neighbors and the extracellularN-CADHERIN/P120 CATENIN ASSOCIATION AT CELL-CELL CONTACTS OCCURS IN CHOLESTEROL-RICH MEMBRANE: Departments of Immunology & Cell Biology, The Scripps Research Institute, 10550, La Jolla, CA 92037 USA 3

  5. Adhesion G-Protein Coupled Receptors: Elusive Hybrids Come of Age

    PubMed Central

    Simundza, Julia; Cowin, Pamela

    2014-01-01

    Adhesion G-protein coupled receptors (GPCRs) are the most recently identified and least understood subfamily of GPCRs. Adhesion GPCRs are characterized by unusually long ectodomains with adhesion-related repeats that facilitate cell-cell and cell-cell matrix contact, as well as a proteolytic cleavage site-containing domain that is a structural hallmark of the family. Their unusual chimeric structure of adhesion-related ectodomain with a seven-pass transmembrane domain and cytoplasmic signaling makes these proteins highly versatile in mediating cellular signaling in response to extracellular adhesion or cell motility events. The ligand binding and cytoplasmic signaling modes for members of this family are beginning to be elucidated, and recent studies have demonstrated critical roles for Adhesion GPCRs in planar polarity and other important cell-cell and cell-matrix interactions during development and morphogenesis, as well as heritable diseases and cancer. PMID:24229322

  6. Focal adhesion linker proteins expression of fibroblast related to adhesion in response to different transmucosal abutment surfaces

    PubMed Central

    Moon, Yeon-Hee; Yoon, Mi-Kyeong; Moon, Jung-Sun; Kang, Jee-Hae; Kim, Sun-Hun; Yang, Hong-Seo

    2013-01-01

    PURPOSE To evaluate adherence of human gingival fibroblasts (HGFs) to transmucosal abutment of dental implant with different surface conditions with time and to investigate the roles of focal adhesion linker proteins (FALPs) involved in HGFs adhesion to abutment surfaces. MATERIALS AND METHODS Morphologies of cultured HGFs on titanium and ceramic discs with different surface were observed by scanning electron microscopy. Biocompatibility and focal adhesion were evaluated by ultrasonic wave application and cell viability assay. FALPs expression levels were assessed by RT-PCR and western blot. RESULTS There seemed to be little difference in biocompatibility and adhesion strength of HGFs depending on the surface conditions and materials. In all experimental groups, the number of cells remaining on the disc surface after ultrasonic wave application increased more than 2 times at 3 days after seeding compared to 1-day cultured cells and this continued until 7 days of culture. FALPs expression levels, especially of vinculin and paxillin, also increased in 5-day cultured cells compared to 1-day cultured fibroblasts on the disc surface. CONCLUSION These results might suggest that the strength of adhesion of fibroblasts to transmucosal abutment surfaces increases with time and it seemed to be related to expressions of FALPs. PMID:24049577

  7. Molecular architecture of a complex between an adhesion protein from the malaria parasite and intracellular adhesion molecule 1.

    PubMed

    Brown, Alan; Turner, Louise; Christoffersen, Stig; Andrews, Katrina A; Szestak, Tadge; Zhao, Yuguang; Larsen, Sine; Craig, Alister G; Higgins, Matthew K

    2013-02-22

    The adhesion of Plasmodium falciparum-infected erythrocytes to human tissues or endothelium is central to the pathology caused by the parasite during malaria. It contributes to the avoidance of parasite clearance by the spleen and to the specific pathologies of cerebral and placental malaria. The PfEMP1 family of adhesive proteins is responsible for this sequestration by mediating interactions with diverse human ligands. In addition, as the primary targets of acquired, protective immunity, the PfEMP1s are potential vaccine candidates. PfEMP1s contain large extracellular ectodomains made from CIDR (cysteine-rich interdomain regions) and DBL (Duffy-binding-like) domains and show extensive variation in sequence, size, and domain organization. Here we use biophysical methods to characterize the entire ?300-kDa ectodomain from IT4VAR13, a protein that interacts with the host receptor, intercellular adhesion molecule-1 (ICAM-1). We show through small angle x-ray scattering that IT4VAR13 is rigid, elongated, and monomeric. We also show that it interacts with ICAM-1 through the DBL? domain alone, forming a 1:1 complex. These studies provide a first low resolution structural view of a PfEMP1 ectodomain in complex with its ligand. They show that it combines a modular domain arrangement consisting of individual ligand binding domains, with a defined higher order architecture that exposes the ICAM-1 binding surface to allow adhesion. PMID:23297413

  8. The effect of moonlighting proteins on the adhesion and aggregation ability of Lactobacillus helveticus.

    PubMed

    Wa?ko, Adam; Polak-Berecka, Magdalena; Paduch, Roman; Jó?wiak, Krzysztof

    2014-10-13

    The goal of this study was to identify moonlighting proteins in Lactobacillus helveticus that play an important role in adhesion and aggregation. The label-free method was used for identification and analysis of expression of cellular proteins. The analysis revealed the presence of eight moonlighting proteins in the cell envelope of Lb. helveticus. The tested strains mainly differed with respect to the presence of S-layer proteins and the level of expression of moonlighting proteins in Lb. helveticus strain T159. These surface proteins give the cell a hydrophobic character and play a role in specific interactions with intestinal epithelium cells and with other bacteria. In Lb. helveticus T159, the S-layer associated with moonlighting proteins could act as adherence factors, which was evidenced by the high capability of adhesion, auto- and coaggregation. The hydrophobicity, adhesion and aggregation abilities provide biological activities in food products and they are regarded as an important criterion for probiotic selection. PMID:25445202

  9. Formulation designs and characterisations of whey-protein based API adhesives

    Microsoft Academic Search

    Zongyan Zhao; Zhenhua Gao; Wenbo Wang; Mingruo Guo

    2011-01-01

    Purpose – The purpose of this paper is to investigate the effects of the components of whey-protein based aqueous polymer-isocyanate (API) adhesives on the bond strength. Design\\/methodology\\/approach – The bond test (according to the JIS K6806-2003 standard), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) were used to characterise the whey-protein based API adhesives with various formulations and

  10. Fast turnover of L1 adhesions in neuronal growth cones involving both surface diffusion and exo/endocytosis of L1 molecules.

    PubMed

    Dequidt, Caroline; Danglot, Lydia; Alberts, Philipp; Galli, Thierry; Choquet, Daniel; Thoumine, Olivier

    2007-08-01

    We investigated the interplay between surface trafficking and binding dynamics of the immunoglobulin cell adhesion molecule L1 at neuronal growth cones. Primary neurons were transfected with L1 constructs bearing thrombin-cleavable green fluorescent protein (GFP), allowing visualization of newly exocytosed L1 or labeling of membrane L1 molecules by Quantum dots. Intracellular L1-GFP vesicles showed preferential centrifugal motion, whereas surface L1-GFP diffused randomly, revealing two pathways to address L1 to adhesive sites. We triggered L1 adhesions using microspheres coated with L1-Fc protein or anti-L1 antibodies, manipulated by optical tweezers. Microspheres coupled to the actin retrograde flow at the growth cone periphery while recruiting L1-GFP molecules, of which 50% relied on exocytosis. Fluorescence recovery after photobleaching experiments revealed a rapid recycling of L1-GFP molecules at L1-Fc (but not anti-L1) bead contacts, attributed to a high lability of L1-L1 bonds at equilibrium. L1-GFP molecules truncated in the intracellular tail as well as neuronal cell adhesion molecules (NrCAMs) missing the clathrin adaptor binding sequence showed both little internalization and reduced turnover rates, indicating a role of endocytosis in the recycling of mature L1 contacts at the base of the growth cone. Thus, unlike for other molecules such as NrCAM or N-cadherin, diffusion/trapping and exo/endocytosis events cooperate to allow the fast renewal of L1 adhesions. PMID:17538021

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

    SciTech Connect

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

    2013-11-22

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

  12. Paxillin, a tyrosine phosphorylated focal adhesion-associated protein binds to the carboxyl terminal domain of focal adhesion kinase.

    PubMed Central

    Hildebrand, J D; Schaller, M D; Parsons, J T

    1995-01-01

    Focal adhesion kinase (pp125FAK or FAK) and paxillin colocalize with integrins in structures called focal adhesions. pp125FAK plays an important role in the transmission of integrin-induced cytoplasmic signals. Paxillin has also been implicated in cell signaling by virtue of its association with the protein tyrosine kinases pp60src and Csk (C-terminal Src kinase) as well as with the adapter/oncoprotein p47gag-crk. In this report we show that endogenous pp125FAK and paxillin form a stable complex both in vivo and in vitro and that this interaction is direct, requiring only pp125FAK and paxillin. The paxillin binding site on pp125FAK has been localized to the carboxy-terminal 148 residues of pp125FAK, but appears to be distinct from the previously identified focal adhesion-targeting sequence also present in the carboxy-terminal domain of pp125FAK. The interaction of paxillin and pp125FAK is independent of the adhesion of cells to the extracellular matrix, as the association can be detected in suspension cells as well as those attached to fibronectin. Images PMID:7579684

  13. Adhesion of mussel foot protein Mefp-5 to mica: an underwater superglue.

    PubMed

    Danner, Eric W; Kan, Yajing; Hammer, Malte U; Israelachvili, Jacob N; Waite, J Herbert

    2012-08-21

    Mussels have a remarkable ability to attach their holdfast, or byssus, opportunistically to a variety of substrata that are wet, saline, corroded, and/or fouled by biofilms. Mytilus edulis foot protein-5 (Mefp-5) is one of several proteins in the byssal adhesive plaque of the mussel M. edulis. The high content of 3,4-dihydroxyphenylalanine (Dopa) (~30 mol %) and its localization near the plaque-substrate interface have often prompted speculation that Mefp-5 plays a key role in adhesion. Using the surface forces apparatus, we show that on mica surfaces Mefp-5 achieves an adhesion energy approaching E(ad) = ~-14 mJ/m(2). This exceeds the adhesion energy of another interfacial protein, Mefp-3, by a factor of 4-5 and is greater than the adhesion between highly oriented monolayers of biotin and streptavidin. The adhesion to mica is notable for its dependence on Dopa, which is most stable under reducing conditions and acidic pH. Mefp-5 also exhibits strong protein-protein interactions with itself as well as with Mefp-3 from M. edulis. PMID:22873939

  14. N-Cadherin, ADAM-10 and Aquaporin 1 expression in lung tissue exposed to fluoro-edenite fibers: an immunohistochemical study.

    PubMed

    Musumeci, Giuseppe; Loreto, Carla; Szychlinska, Marta Anna; Imbesi, Rosa; Rapisarda, Venerando; Aiello, Flavia Concetta; Castorina, Sergio; Castrogiovanni, Paola

    2015-08-01

    Fluoro-edenite (FE) fibers are similar to other amphibole asbestos fibers. The scientific relevance of FE is due to its ability to lead to chronic inflammation and carcinogenesis in lung tissue shown after its inhalation. These fibers stimulate aberrant host cell proliferation and induce the release of cytokines, growth factors, reactive oxygen and nitrite species, which results in DNA damage. In previous studies, we showed that FE induces functional modifications in sheep and human lung fibroblasts and alveolar epithelial cells, where the overexpression of several molecules probably involved in pathological cellular mechanisms induced by FE exposition have been detected. However, the mechanisms of cellular and molecular toxicity and the cellular response to FE fibers are still not well known. N-cadherin, ADAM-10 and AQP1 are molecules involved in carcinogenesis and in inflammatory process. In this study we analyzed, through immunohistochemistry, their expression in the lung tissue of sheep exposed to FE. Our results showed different patterns of immunolabeling for N-cadherin, ADAM-10 and AQP1. N-cadherin and ADAM-10 were more expressed in FE exposed lung tissue, when compared with the control. On the contrary, AQP1 was more expressed in non exposed lung tissue. These results suggest that N-Cadherin, ADAM-10 and AQP1 are probably involved in different pathological processes induced by FE fiber exposition. The aim of the study was to better understand the mechanisms of cellular and molecular toxicity and of cellular response to FE fibers in order to identify, in the future, a possible therapeutic intervention in cases of FE-associated pathogenesis. PMID:25757887

  15. Expression of lncRNA-CCAT1, E-cadherin and N-cadherin in colorectal cancer and its clinical significance

    PubMed Central

    Ye, Zhenyu; Zhou, Ming; Tian, Bin; Wu, Bin; Li, Juncheng

    2015-01-01

    Objective: To explore the expression and clinical significance of IncRNA-CCAT and EMT related molecule E-cadherin and N-cadherin in colorectal cancer. Methods: The expression of IncRNA-CCAT1, E-cadherin and N-cadherin in 37 colorectal cancer tissue and para-carcinoma tissue was detected using qRT-PCR method, and the correlation of expression level with clinical and pathological features was studied. Results: The expression of IncRNA-CCAT1 in tumor tissue was significantly higher than that in normal para-carcinoma tissue (P < 0.001), and the expression level of CCAT1was significantly correlated with local infiltration depth (P < 0.001), tumor staging (P < 0.001), vascular invasion (P < 0.001) and CA19-9 level (P < 0.001); but not related with age, gender, location of tumor, tumor differentiation level, size of primary lesion and level of CEA (P > 0.05). The expression of E-cadherin in tumor tissues was significantly lower than in normal para-carcinoma tissues (P < 0.001), and the expression of N-cadherin was significantly higher than that in normal para-carcinoma tissues. The decrease in expression of E-cadherin and increase in expression of N-cadherin were significantly correlated with local infiltration depth (P < 0.001), tumor staging (P < 0.001), vascular invasion (P < 0.001), tumor differentiation level (P < 0.001) and CA19-9 level (P < 0.001), however not related with age, gender, tumor location, size of primary lesion and CEA level (P > 0.05). Conclusion: CCAT1 plays an important role in the genesis, development, invasion and metastasis; it mediates the EMT process of colorectal cancer; and it’s expected to be a new marker and treatment target in colorectal diagnosis and treatment.

  16. Adhesion molecules during somitogenesis in the avian embryo.

    PubMed

    Duband, J L; Dufour, S; Hatta, K; Takeichi, M; Edelman, G M; Thiery, J P

    1987-05-01

    In avian embryos, somites constitute the morphological unit of the metameric pattern. Somites are epithelia formed from a mesenchyme, the segmental plate, and are subsequently reorganized into dermatome, myotome, and sclerotome. In this study, we used somitogenesis as a basis to examine tissue remodeling during early vertebrate morphogenesis. Particular emphasis was put on the distribution and possible complementary roles of adhesion-promoting molecules, neural cell adhesion molecule (N-CAM), N-cadherin, fibronectin, and laminin. Both segmental plate and somitic cells exhibited in vitro calcium-dependent and calcium-independent systems of cell aggregation that could be inhibited respectively by anti-N-cadherin and anti-N-CAM antibodies. In vivo, the spatio-temporal expression of N-cadherin was closely associated with both the formation and local disruption of the somites. In contrast, changes in the prevalence of N-CAM did not strictly accompany the remodeling of the somitic epithelium into dermamyotome and sclerotome. It was also observed that fibronectin and laminin were reorganized secondarily in the extracellular spaces after CAM-mediated contacts were modulated. In an in vitro culture system of somites, N-cadherin was lost on individual cells released from somite explants and was reexpressed when these cells reached confluence and established intercellular contacts. In an assay of tissue dissociation in vitro, antibodies to N-cadherin or medium devoid of calcium strongly and reversibly dissociated explants of segmental plates and somites. Antibodies to N-CAM exhibited a smaller disrupting effect only on segmental plate explants. In contrast, antibodies to fibronectin and laminin did not perturb the cohesion of cells within the explants. These results emphasize the possible role of cell surface modulation of CAMs during the formation and remodeling of some transient embryonic epithelia. It is suggested that N-cadherin plays a major role in the control of tissue remodeling, a process in which N-CAM is also involved but to a lesser extent. The substratum adhesion molecules, fibronectin and laminin, do not appear to play a primary role in the regulation of these processes but may participate in cell positioning and in the stabilization of the epithelial structures. PMID:3553211

  17. Characteristics and Molecular Mechanism of Adhesion Proteins on Reused Hemodialysis Membranes

    Microsoft Academic Search

    Xiulin Xu; Yujing Yang; Naishuo Zhu

    2009-01-01

    In order to study the mechanism of protein adhesion on the Fresenius F6 polysulfone membrane dialyzer, two-dimensional gel electrophoresis, LC-ESI-MS\\/MS and bioinformatics methods were used to analyze the protein which adhered to the dialyzer membrane. Six of the adhered proteins account for more than 50% of the total 179 proteins, i.e. ficolin precursor, complement C3 precursor, 3 variants of MASP1

  18. Osteoblast attachment to a textured surface in the absence of exogenous adhesion proteins.

    PubMed

    Mata, Alvaro; Su, Xiaowei; Fleischman, Aaron J; Roy, Shuvo; Banks, Bruce A; Miller, Sharon K; Midura, Ronald J

    2003-12-01

    The present study investigated whether osteoblasts could attach to a culture substratum through a surface texture-dependent mechanism. Four test groups were used: (A) untextured, and three texture groups with maximum feature sizes of (B) <0.5 microm, (C) 2 microm, and (D) 4 microm, respectively. All surfaces were coated with the nonadhesive protein bovine serum albumin (BSA). Osteoblasts were allowed to adhere in serum-free medium for either 1 or 4 h, at which time nonadherent cells were removed. At 4 h, untextured surface A exhibited no cell attachment, while textured surfaces B, C, and D exhibited 9%, 32%, and 16% cell adhesion, respectively. At 16 h of incubation, adherent osteoblasts on textured surface C exhibited focal adhesion contacts and microfilament stress-fiber bundles. These results indicate that microtextured surfaces in the absence of exogenous adhesive proteins can facilitate osteoblast adhesion. PMID:15376920

  19. Fabrication of nanostructures of polyethylene glycol for applications to protein adsorption and cell adhesion

    NASA Astrophysics Data System (ADS)

    Kim, P.; Kim, D. H.; Kim, B.; Choi, S. K.; Lee, S. H.; Khademhosseini, A.; Langer, R.; Suh, K. Y.

    2005-10-01

    A simple method was developed to fabricate polyethylene glycol (PEG) nanostructures using capillary lithography mediated by ultraviolet (UV) exposure. Acrylate-containing PEG monomers, such as PEG dimethacrylate (PEG-DMA, MW = 330), were photo-cross-linked under UV exposure to generate patterned structures. In comparison to unpatterned PEG films, hydrophobicity of PEG nanostructure modified surfaces was significantly enhanced. This could be attributed to trapped air in the nanostructures as supported by water contact angle measurements. Proteins (fibronectin, immunoglobulin, and albumin) and cells (fibroblasts and P19 EC cells) were examined on the modified surfaces to test for the level of protein adsorption and cell adhesion. It was found that proteins and cells preferred to adhere on nanostructured PEG surfaces in comparison to unpatterned PEG films; however, this level of adhesion was significantly lower than that of glass controls. These results suggest that capillary lithography can be used to fabricate PEG nanostructures capable of modifying protein and cell adhesive properties of surfaces.

  20. Quantifying adhesion mechanisms and dynamics of human hematopoietic stem and progenitor cells.

    PubMed

    Burk, Alexandra S; Monzel, Cornelia; Yoshikawa, Hiroshi Y; Wuchter, Patrick; Saffrich, Rainer; Eckstein, Volker; Tanaka, Motomu; Ho, Anthony D

    2015-01-01

    Using planar lipid membranes with precisely defined concentrations of specific ligands, we have determined the binding strength between human hematopoietic stem cells (HSC) and the bone marrow niche. The relative significance of HSC adhesion to the surrogate niche models via SDF1?-CXCR4 or N-cadherin axes was quantified by (a) the fraction of adherent cells, (b) the area of tight adhesion, and (c) the critical pressure for cell detachment. We have demonstrated that the binding of HSC to the niche model is a cooperative process, and the adhesion mediated by the CXCR4- SDF1? axis is stronger than that by homophilic N-cadherin binding. The statistical image analysis of stochastic morphological dynamics unraveled that HSC dissipated energy by undergoing oscillatory deformation. The combination of an in vitro niche model and novel physical tools has enabled us to quantitatively determine the relative significance of binding mechanisms between normal HSC versus leukemia blasts to the bone marrow niche. PMID:25824493

  1. Binding of the WASP/N-WASP-Interacting Protein WIP to Actin Regulates Focal Adhesion Assembly and Adhesion

    PubMed Central

    Massaad, Michel J.; Kumar, Lalit; Koduru, Suresh; Sasahara, Yoji; Anton, Ines; Bhasin, Manoj; Libermann, Towia

    2014-01-01

    The actin cytoskeleton is essential for cell adhesion and migration, functions important for tumor invasion. In addition to binding N-WASP/WASP, WIP binds and stabilizes F-actin. WIP?/? fibroblasts were used to test the role of WIP in F-actin function. WIP?/? cells had defective focal adhesion (FA), stress fiber assembly, and adherence to substrates, functions that were restored by transduction of wild-type WIP. Protein and mRNA levels of several FA constituents regulated by the myocardin-related transcription factor (MRTF)–serum response factor (SRF) transcription factor complex were reduced in WIP?/? fibroblasts. The level of G-actin, which sequesters MRTF in the cytoplasm, was increased, and nuclear localization of MRTF-A and SRF was reduced, in WIP?/? fibroblasts. Transfection of an MRTF-A mutant that constitutively translocates to the nucleus or transfection of constitutively active SRF restored FA and stress fiber assembly. Fibroblasts from knock-in mice expressing a WIP mutant that fails to bind actin phenocopied WIP?/? fibroblasts. Thus, WIP is a novel regulator of FA assembly and cell adhesion. PMID:24797074

  2. Cerivastatin ameliorates high insulin-enhanced neutrophil–endothelial cell adhesion and endothelial intercellular adhesion molecule-1 expression by inhibiting mitogen-activated protein kinase activation

    Microsoft Academic Search

    Masahiro Okouchi; Naotsuka Okayama; Hitoshi Omi; Kenro Imaeda; Manabu Shimizu; Tatsuya Fukutomi; Makoto Itoh

    2003-01-01

    Background and aimThere is growing evidence that hyperinsulinemia is linked to the development of atherosclerosis in patients with diabetes. We demonstrated previously that high insulin exacerbates neutrophil–endothelial cell adhesion and endothelial intercellular adhesion molecule (ICAM)-1 expression through activation of protein kinase C (PKC) and mitogen-activated protein (MAP) kinase. Though 3-hydroxymethyl-3-glutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) have been employed as

  3. Secreted Frizzled-related protein 1 (sFRP1) regulates spermatid adhesion in the testis via dephosphorylation of focal adhesion kinase and the nectin-3 adhesion protein complex

    PubMed Central

    Wong, Elissa W. P.; Lee, Will M.; Cheng, C. Yan

    2013-01-01

    Development of spermatozoa in adult mammalian testis during spermatogenesis involves extensive cell migration and differentiation. Spermatogonia that reside at the basal compartment of the seminiferous epithelium differentiate into more advanced germ cell types that migrate toward the apical compartment until elongated spermatids are released into the tubule lumen during spermiation. Apical ectoplasmic specialization (ES; a testis-specific anchoring junction) is the only cell junction that anchors and maintains the polarity of elongating/elongated spermatids (step 8–19 spermatids) in the epithelium. Little is known regarding the signaling pathways that trigger the disassembly of the apical ES at spermiation. Here, we show that secreted Frizzled-related protein 1 (sFRP1), a putative tumor suppressor gene that is frequently down-regulated in multiple carcinomas, is a crucial regulatory protein for spermiation. The expression of sFRP1 is tightly regulated in adult rat testis to control spermatid adhesion and sperm release at spermiation. Down-regulation of sFRP1 during testicular development was found to coincide with the onset of the first wave of spermiation at approximately age 45 d postpartum, implying that sFRP1 might be correlated with elongated spermatid adhesion conferred by the apical ES before spermiation. Indeed, administration of sFRP1 recombinant protein to the testis in vivo delayed spermiation, which was accompanied by down-regulation of phosphorylated (p)-focal adhesion kinase (FAK)-Tyr397 and retention of nectin-3 adhesion protein at the apical ES. To further investigate the functional relationship between p-FAK-Tyr397 and localization of nectin-3, we overexpressed sFRP1 using lentiviral vectors in the Sertoli-germ cell coculture system. Consistent with the in vivo findings, overexpression of sFRP1 induced down-regulation of p-FAK-Tyr397, leading to a decline in phosphorylation of nectin-3. In summary, this report highlights the critical role of sFRP1 in regulating spermiation via its effects on the FAK signaling and retention of nectin-3 adhesion complex at the apical ES.—Wong, E. W. P., Lee, W. M., Cheng, C. Y. Secreted Frizzled-related protein 1 (sFRP1) regulates spermatid adhesion in the testis via dephosphorylation of focal adhesion kinase and the nectin-3 adhesion protein complex. PMID:23073828

  4. Modulation of Drosophila Retinal Epithelial Integrity by the Adhesion Proteins Capricious and Tartan

    PubMed Central

    Mao, Yanlan; Kerr, Martin; Freeman, Matthew

    2008-01-01

    Background The development of the Drosophila eye imaginal disc requires complex epithelial rearrangements. Cells of the morphogenetic furrow are apically constricted and this leads to a physical indentation in the epithelium. Posterior to the furrow, cells start to rearrange into distinct clusters and eventually form a precisely patterned array of ommatidia. These morphogenetic processes include regulated changes of adhesion between cells. Methodology/Principal Findings Here, we show that two transmembrane adhesion proteins, Capricious and Tartan, have dynamic and complementary expression patterns in the eye imaginal disc. We also describe novel null mutations in capricious and double null mutations in capricious and tartan. We report that they have redundant functions in regulating the architecture of the morphogenetic furrow and ommatidial spacing. Conclusions/Significance We conclude that Capricious and Tartan contribute to the adhesive properties of the cells in the morphogenetic furrow and that this regulated adhesion participates in the control of spacing ommatidial clusters. PMID:18350163

  5. Interaction between urokinase receptor and heat shock protein MRJ enhances cell adhesion.

    PubMed

    De Bock, Charles Edo; Lin, Zhen; Mekkawy, Ahmed H; Byrne, Jennifer A; Wang, Yao

    2010-05-01

    The urokinase-type plasminogen activator receptor (uPAR) has diverse biological functions including roles in proteolysis, cell adhesion and cellular signaling. We identified a heat shock protein MRJ (DNAJB6) as a novel uPAR-interacting protein in a yeast two-hybrid screen and confirmed the interaction and co-localization by GST-pull down assays, and co-immunoprecipitation in cells transfected with MRJ. Endogenous interaction between uPAR and MRJ was also detected in breast cancer MDA-MB-231 cells. Deletion mapping demonstrated that the C-terminal region of MRJ is required to mediate its interaction with uPAR. To understand the biological function of the uPAR-MRJ complex, we determined whether MRJ regulated uPAR mediated adhesion to vitronectin in human embryonic kidney (HEK) 293 cells stably transfected with uPAR. After transfection with full length MRJ, there was a 50% increase in cell adhesion compared to the mock transfected control (p<0.01). This increase in adhesion is dependent on the uPAR/full length MRJ interaction as cells transfected with the mutant construct containing only N-terminal region or C-terminal region of MRJ had no increase in cell adhesion. The observed increase in adhesion to vitronectin by MRJ was also blocked by an anti-uPAR domain I antibody suggesting that the induced adhesion is at least in part contributed by uPAR on the cell surface. These data provide a novel mechanism by which uPAR plays a role in cell adhesion to vitronectin. PMID:20372789

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

    PubMed Central

    2014-01-01

    Background 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. Methods 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-?B activation, and hence cell adhesion to human umbilical vein endothelial cells (HUVECs). 5-Aminoimidazole-4-carboxamide 1-?-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. Results Treatment with resistin increased the adhesion of SK-Hep1 cells to HUVECs and concomitantly induced NF-?B 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-?B-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. Conclusions 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. PMID:24555415

  7. Flavonoids inhibit cytokine-induced endothelial cell adhesion protein gene expression.

    PubMed Central

    Gerritsen, M. E.; Carley, W. W.; Ranges, G. E.; Shen, C. P.; Phan, S. A.; Ligon, G. F.; Perry, C. A.

    1995-01-01

    Treatment of human endothelial cells with cytokines such as interleukin-1, tumor necrosis factor-alpha (TNF-alpha) or interferon-gamma induces the expression of specific leukocyte adhesion molecules on the endothelial cell surface. Interfering with either leukocyte adhesion or adhesion protein upregulation is an important therapeutic target as evidenced by the potent anti-inflammatory actions of neutralizing antibodies to these ligands in various animal models and in patients. In the present study we report that cotreatment of human endothelial cells with certain hydroxyflavones and flavanols blocks cytokine-induced ICAM-1, VCAM-1, and E-selectin expression on human endothelial cells. One of the most potent flavones, apigenin, exhibited a dose- and time-dependent, reversible effect on adhesion protein expression as well as inhibiting adhesion protein upregulation at the transcriptional level. Apigenin also inhibited IL-1 alpha-induced prostaglandin synthesis and TNF-alpha-induced IL-6 and IL-8 production, suggesting that the hydroxyflavones may act as general inhibitors of cytokine-induced gene expression. Although apigenin did not inhibit TNF-alpha-induced nuclear translocation of NF-kappa B(p50(NFKB1)/p65(RelA)) we found this flavonoid did inhibit TNF-alpha induced beta-galactosidase activity in SW480 cells stably transfected with a beta-galactosidase reporter construct driven by four NF-kappa B elements, suggesting an action on NF-kappa B transcriptional activation. Adhesion of leukocytes to cytokine-treated endothelial cells was blocked in endothelial cells cotreated with apigenin. Finally, apigenin demonstrated potent anti-inflammatory activity in carrageenan induced rat paw edema and delayed type hypersensitivity in the mouse. We conclude that flavonoids offer important therapeutic potential for the treatment of a variety of inflammatory diseases involving an increase in leukocyte adhesion and trafficking. Images Figure 7 Figure 8 Figure 11 PMID:7543732

  8. Diversity of bone matrix adhesion proteins modulates osteoblast attachment and organization of actin cytoskeleton.

    PubMed

    Demais, V; Audrain, C; Mabilleau, G; Chappard, D; Baslé, M F

    2014-06-01

    Interaction of cells with extracellular matrix is an essential event for differentiation, proliferation and activity of osteoblasts. In bone, binding of osteoblasts to bone matrix is required to determine specific activities of the cells and to synthesize matrix bone proteins. Integrins are the major cell receptors involved in the cell linkage to matrix proteins such as fibronectin, type I collagen and vitronectin, via the RGD-sequences. In this study, cultures of osteoblast-like cells (Saos-2) were done on coated glass coverslips in various culture conditions: DMEM alone or DMEM supplemented with poly-L-lysine (PL), fetal calf serum (FCS), fibronectin (FN), vitronectin (VN) and type I collagen (Col-I). The aim of the study was to determine the specific effect of these bone matrix proteins on cell adherence and morphology and on the cytoskeleton status. Morphological characteristics of cultured cells were studied using scanning electron microscopy and image analysis. The heterogeneity of cytoskeleton was studied using fractal analysis (skyscrapers and blanket algorithms) after specific preparation of cells to expose the cytoskeleton. FAK and MAPK signaling pathways were studied by western blotting in these various culture conditions. Results demonstrated that cell adhesion was reduced with PL and VN after 240 min. After 60 min of adhesion, cytoskeleton organization was enhanced with FN, VN and Col-I. No difference in FAK phosphorylation was observed but MAPK phosphorylation was modulated by specific adhesion on extracellular proteins. These results indicate that culture conditions modulate cell adhesion, cytoskeleton organization and intracellular protein pathways according to extracellular proteins present for adhesion. PMID:24735942

  9. Investigation of Alginate Binding to Germanium and Polystyrene Substrata Conditioned with Mussel Adhesive Protein

    Microsoft Academic Search

    P. A. Suci; G. G. Geesey

    1995-01-01

    Binding of alginate from Macrocystis pyrifera (kelp) to germanium and polystyrene substrata conditioned with mussel adhesive protein (MAP) from Mytilis edulis , to germanium substrata conditioned with bovine serum albumin (BSA) and polylysine, and to germanium substrata coated with aminopropyltriethoxysilane (APS) was investigated using attenuated total reflection Fourier transform infrared spectrometry. Binding of alginate to MAP appears to be proportional

  10. Interspecific Variations in Adhesive Protein Sequences of Mytilus edulis, M. galloprovincialis, and M. trossulus

    Microsoft Academic Search

    KOJI INOUE; J. HERBERT WAITE; MAKOTO MATSUOKA; SATOSHI ODO; SHIGEAKI HARAYAMA

    1995-01-01

    Variation in the adhesive protein gene se- quences of Mytilus edulis, M. galloprovincialis, and M. trossulus collected in Delaware, Kamaishi (Japan), and Alaska, respectively, was analyzed by the polymerase chain reaction (PCR) using two sets of oligonucleotide primers. The first set, Me 13 and Me 14, was designed to amplify the repetitive region. The length of the amplified fragments was

  11. Effects of monocrotaline pyrrole and thrombin on pulmonary endothelial cell junction and matrix adhesion proteins

    Microsoft Academic Search

    Debra W Taylor; Michael W Lamé; Lynn S Nakayama; H. J Segall; Dennis W Wilson

    2003-01-01

    Previous work in our laboratory has shown that monocrotaline pyrrole (MCTP) interacts with actin and potentiates thrombin-mediated endothelial barrier permeability through increasing the overall surface area of intercellular gaps. To better characterize endothelial barrier leak in this model, we examined the effects of MCTP and thrombin on the localization and structure of three adhesion associated proteins that directly or indirectly

  12. Different Roles for Lactococcal Aggregation Factor and Mucin Binding Protein in Adhesion to Gastrointestinal Mucosa

    PubMed Central

    Luki?, Jovanka; Strahini?, Ivana; Jov?i?, Branko; Filipi?, Brankica; Topisirovi?, Ljubiša; Koji?, Milan

    2012-01-01

    Adhesion of bacteria to mucosal surfaces and epithelial cells is one of the key features for the selection of probiotics. In this study, we assessed the adhesion property of Lactococcus lactis subsp. lactis BGKP1 based on its strong autoaggregation phenotype and the presence of the mucin binding protein (MbpL). Genes involved in aggregation (aggL) and possible interaction with mucin (mbpL), present on the same plasmid pKP1, were previously separately cloned in the plasmid pAZIL. In vivo and in vitro experiments revealed potentially different physiological roles of these two proteins in the process of adherence to the intestine during the passage of the strain through the gastrointestinal tract. We correlated the in vitro and in vivo aggregation of the BGKP1-20 carrying plasmid with aggL to binding to the colonic mucus through nonspecific hydrophobic interactions. The expression of AggL on the bacterial cell surface significantly increased the hydrophobicity of the strain. On the other hand, the presence of AggL in the strain reduced its ability to adhere to the ileum. Moreover, MbpL protein showed an affinity to bind gastric type mucin proteins such as MUC5AC. This protein did not contribute to the binding of the strain to the ileal or colonic part of the intestine. Different potential functions of lactococcal AggL and MbpL proteins in the process of adhesion to the gastrointestinal tract are proposed. PMID:22961901

  13. Specific adhesion of membranes simultaneously supports dual heterogeneities in lipids and proteins.

    PubMed

    Shindell, O; Mica, N; Ritzer, M; Gordon, V D

    2015-06-28

    Membrane adhesion is a vital component of many biological processes. Heterogeneities in lipid and protein composition are often associated with the adhesion site. These heterogeneities are thought to play functional roles in facilitating signalling. Here we experimentally examine this phenomenon using model membranes made of a mixture of lipids that is near a phase boundary at room temperature. Non-adherent model membranes are in a well-mixed, disordered-fluid lipid phase indicated by homogeneous distribution of a fluorescent dye that is a marker for the fluid-disordered (Ld) phase. We specifically adhere membranes to a flat substrate bilayer using biotin-avidin binding. Adhesion produces two types of coexisting heterogeneities: an ordered lipid phase that excludes binding proteins and the fluorescent membrane dye, and a disordered lipid phase that is enriched in both binding proteins and membrane dye compared with the non-adhered portion of the same membrane. Thus, a single type of adhesion interaction (biotin-avidin binding), in an initially-homogeneous system, simultaneously stabilizes both ordered-phase and disordered-phase heterogeneities that are compositionally distinct from the non-adhered portion of the vesicle. These heterogeneities are long-lived and unchanged upon increased temperature. PMID:25870864

  14. A self-assembled monolayer-based micropatterned array for controlling cell adhesion and protein adsorption.

    PubMed

    Kim, Dong Jin; Lee, Jong Min; Park, Jin-Goo; Chung, Bong Geun

    2011-05-01

    We developed a surface micropatterning technique to control the cell adhesion and protein adsorption. This micropatterned array system was fabricated by a photolithography technique and self-assembled monolayer (SAM) deposition. It was hypothesized that the wettability and functional terminal group would regulate cell adhesion and protein adsorption. To demonstrate this hypothesis, glass-based micropatterned arrays with various functional terminal groups, such as amine (NH(2)) group (3-aminopropyl-triethoxysilane, APT), methyl (CH(3)) group (trichlorovinylsilane, TVS), and fluorocarbon (CF(3)) group (trichloro(1H, 1H, 2H, 2H-perfluorooctyl)silane, FOTS), were used. The contact angle was measured to determine the hydrophilic and hydrophobic properties of materials, demonstrating that TVS and FOTS were hydrophobic, whereas APTs were relatively hydrophilic. The cell adhesion was significantly affected by the wettability, showing that the cells were not adhered to hydrophobic surfaces, such as TVS and FOTS. Thus, the cells were selectively adhered to glass substrates within TVS- and FOTS-based micropatterned arrays. However, the cells were randomly adhered to APTs-based micropatterned arrays due to hydrophilic property of APTs. Furthermore, the protein adsorption of the SAM-based micropatterned array was analyzed, showing that the protein was more absorbed to the TVS surface. The surface functional terminal group enabled the control of protein adsorption. Therefore, this SAM-based micropatterned array system enabled the control of cell adhesion and protein adsorption and could be a potentially powerful tool for regulating the cell-cell interactions in a well-defined microenvironment. PMID:21449031

  15. Ubiquitous distribution of salts and proteins in spider glue enhances spider silk adhesion

    PubMed Central

    Amarpuri, Gaurav; Chaurasia, Vishal; Jain, Dharamdeep; Blackledge, Todd A.; Dhinojwala, Ali

    2015-01-01

    Modern orb-weaving spiders use micron-sized glue droplets on their viscid silk to retain prey in webs. A combination of low molecular weight salts and proteins makes the glue viscoelastic and humidity responsive in a way not easily achieved by synthetic adhesives. Optically, the glue droplet shows a heterogeneous structure, but the spatial arrangement of its chemical components is poorly understood. Here, we use optical and confocal Raman microscopy to show that salts and proteins are present ubiquitously throughout the droplet. The distribution of adhesive proteins in the peripheral region explains the superior prey capture performance of orb webs as it enables the entire surface area of the glue droplet to act as a site for prey capture. The presence of salts throughout the droplet explains the recent Solid-State NMR results that show salts directly facilitate protein mobility. Understanding the function of individual glue components and the role of the droplet's macro-structure can help in designing better synthetic adhesives for humid environments. PMID:25761668

  16. Protein Adhesion and Ion Substitution (on\\/in)to Minerals

    Microsoft Academic Search

    L. Charlet; A. Fernandez Martinez; Y. Chapron; N. Sahai; G. Cuello; J. Brendle; C. Marichal

    2008-01-01

    Arsenic and pathogenic prion protein-scrapie (PrPsc) are important contaminants which may soil and water for decades, unless they are removed by sorption. Two sorption mechanisms will be discussed, namely the organics (Prp and single aminoacid) adsorption on clay and the arsenic substitution in gypsum. The elucidation of these contrasted mechanisms will be shown to request complementary molecular-mechanical simulations with experimental

  17. Endocytosis Regulates Cell Soma Translocation and the Distribution of Adhesion Proteins in Migrating Neurons

    PubMed Central

    Shieh, Jennifer C.; Schaar, Bruce T.; Srinivasan, Karpagam; Brodsky, Frances M.; McConnell, Susan K.

    2011-01-01

    Newborn neurons migrate from their birthplace to their final location to form a properly functioning nervous system. During these movements, young neurons must attach and subsequently detach from their substrate to facilitate migration, but little is known about the mechanisms cells use to release their attachments. We show that the machinery for clathrin-mediated endocytosis is positioned to regulate the distribution of adhesion proteins in a subcellular region just proximal to the neuronal cell body. Inhibiting clathrin or dynamin function impedes the movement of migrating neurons both in vitro and in vivo. Inhibiting dynamin function in vitro shifts the distribution of adhesion proteins to the rear of the cell. These results suggest that endocytosis may play a critical role in regulating substrate detachment to enable cell body translocation in migrating neurons. PMID:21445347

  18. Intercellular adhesion molecule-1 is a regulator of blood–testis barrier function

    PubMed Central

    Xiao, Xiang; Cheng, C. Yan; Mruk, Dolores D.

    2012-01-01

    Summary The mechanism underlying the movement of preleptotene/leptotene spermatocytes across the blood–testis barrier (BTB) during spermatogenesis is not well understood largely owing to the fact that the BTB, unlike most other blood–tissue barriers, is composed of several co-existing and co-functioning junction types. In the present study, we show that intercellular adhesion molecule-1 [ICAM-1, a Sertoli and germ cell adhesion protein having five immunoglobulin (Ig)-like domains, in addition to transmembrane and cytoplasmic domains] is a regulator of BTB integrity. Initial experiments showed ICAM-1 to co-immunoprecipitate and co-localize with tight junction and basal ectoplasmic specialization proteins such as occludin and N-cadherin, which contribute to BTB function. More importantly, overexpression of ICAM-1 in Sertoli cells in vitro enhanced barrier function when monitored by transepithelial electrical resistance measurements, illustrating that ICAM-1-mediated adhesion can promote BTB integrity. On the other hand, overexpression of a truncated form of ICAM-1 that consisted only of the five Ig-like domains (sICAM-1; this form of ICAM-1 is known to be secreted) elicited an opposite effect when Sertoli cell barrier function was found to be perturbed in vitro; in this case, sICAM-1 overexpression resulted in the downregulation of several BTB constituent proteins, which was probably mediated by Pyk2/p-Pyk2-Y402 and c-Src/p-Src-Y530. These findings were expanded to the in vivo level when BTB function was found to be disrupted following sICAM-1 overexpression. These data illustrate the existence of a unique mechanism in the mammalian testis where ICAM-1 can either positively or negatively regulate BTB function. PMID:22976294

  19. Wetting of soy protein adhesives modified by urea on wood surfaces

    Microsoft Academic Search

    Hua-Neng Xu; Qiu-Yun Shen; Xiao-Kun Ouyang; Li-Ye Yang

    Wetting of soy protein adhesives modified by urea on wood surfaces was investigated with sessile liquid droplet method. Dynamic\\u000a contact angles were used to illustrate the wetting process. The effects of wood surface roughness and urea concentration on\\u000a contact angles were investigated. Moreover, two wetting models were used to describe the dynamic contact angle process, in\\u000a which the contact angle

  20. Biphasic influence of Miz1 on neural crest development by regulating cell survival and apical adhesion complex formation in the developing neural tube.

    PubMed

    Kerosuo, Laura; Bronner, Marianne E

    2014-02-01

    Myc interacting zinc finger protein-1 (Miz1) is a transcription factor known to regulate cell cycle- and cell adhesion-related genes in cancer. Here we show that Miz1 also plays a critical role in neural crest development. In the chick, Miz1 is expressed throughout the neural plate and closing neural tube. Its morpholino-mediated knockdown affects neural crest precursor survival, leading to reduction of neural plate border and neural crest specifier genes Msx-1, Pax7, FoxD3, and Sox10. Of interest, Miz1 loss also causes marked reduction of adhesion molecules (N-cadherin, cadherin6B, and ?1-catenin) with a concomitant increase of E-cadherin in the neural folds, likely leading to delayed and decreased neural crest emigration. Conversely, Miz1 overexpression results in up-regulation of cadherin6B and FoxD3 expression in the neural folds/neural tube, leading to premature neural crest emigration and increased number of migratory crest cells. Although Miz1 loss effects cell survival and proliferation throughout the neural plate, the neural progenitor marker Sox2 was unaffected, suggesting a neural crest-selective effect. The results suggest that Miz1 is important not only for survival of neural crest precursors, but also for maintenance of integrity of the neural folds and tube, via correct formation of the apical adhesion complex therein. PMID:24307680

  1. The tumor suppressor Scrib interacts with the zyxin-related protein LPP, which shuttles between cell adhesion sites and the nucleus

    Microsoft Academic Search

    Sandra MP Meulemans; Philippe Alen; Torik AY Ayoubi; Erik Jansen; Wim JM Van de Ven

    2005-01-01

    BACKGROUND: At sites of cell adhesion, proteins exist that not only perform structural tasks but also have a signaling function. Previously, we found that the Lipoma Preferred Partner (LPP) protein is localized at sites of cell adhesion such as focal adhesions and cell-cell contacts, and shuttles to the nucleus where it has transcriptional activation capacity. LPP is a member of

  2. Lectin Receptor Kinases Participate in Protein-Protein Interactions to Mediate Plasma Membrane-Cell Wall Adhesions in Arabidopsis1

    PubMed Central

    Gouget, Anne; Senchou, Virginie; Govers, Francine; Sanson, Arnaud; Barre, Annick; Rougé, Pierre; Pont-Lezica, Rafael; Canut, Hervé

    2006-01-01

    Interactions between plant cell walls and plasma membranes are essential for cells to function properly, but the molecules that mediate the structural continuity between wall and membrane are unknown. Some of these interactions, which are visualized upon tissue plasmolysis in Arabidopsis (Arabidopsis thaliana), are disrupted by the RGD (arginine-glycine-aspartic acid) tripeptide sequence, a characteristic cell adhesion motif in mammals. In planta induced-O (IPI-O) is an RGD-containing protein from the plant pathogen Phytophthora infestans that can disrupt cell wall-plasma membrane adhesions through its RGD motif. To identify peptide sequences that specifically bind the RGD motif of the IPI-O protein and potentially play a role in receptor recognition, we screened a heptamer peptide library displayed in a filamentous phage and selected two peptides acting as inhibitors of the plasma membrane RGD-binding activity of Arabidopsis. Moreover, the two peptides also disrupted cell wall-plasma membrane adhesions. Sequence comparison of the RGD-binding peptides with the Arabidopsis proteome revealed 12 proteins containing amino acid sequences in their extracellular domains common with the two RGD-binding peptides. Eight belong to the receptor-like kinase family, four of which have a lectin-like extracellular domain. The lectin domain of one of these, At5g60300, recognized the RGD motif both in peptides and proteins. These results imply that lectin receptor kinases are involved in protein-protein interactions with RGD-containing proteins as potential ligands, and play a structural and signaling role at the plant cell surfaces. PMID:16361528

  3. Purification and partial characterization of an outer membrane protein involved in the adhesion of Rahnella aquatilis to wheat roots

    Microsoft Academic Search

    W. Achouak; R. De Mot; T. Heulin

    1995-01-01

    A 38 kDa major outer membrane protein isolated from the nitrogen-fixing enterobacterium Rahnella aquatilis CF3 showed high affinity for wheat roots in an in vitro adhesion assay. Antibodies directed against the 38 kDa protein were able to bind to whole cells of R. aquatilis and strongly reduced attachment to wheat roots, suggesting a role in adhesion to and colonization of

  4. Human Siglec-10 can bind to vascular adhesion protein-1 and serves as its substrate

    PubMed Central

    Kivi, Elina; Elima, Kati; Aalto, Kristiina; Nymalm, Yvonne; Auvinen, Kaisa; Koivunen, Erkki; Otto, Diana M.; Crocker, Paul R.; Salminen, Tiina A.; Salmi, Marko

    2009-01-01

    Leukocytes migrate from the blood into areas of inflammation by interacting with various adhesion molecules on endothelial cells. Vascular adhesion protein-1 (VAP-1) is a glycoprotein expressed on inflamed endothelium where it plays a dual role: it is both an enzyme that oxidizes primary amines and an adhesin that is involved in leukocyte trafficking to sites of inflammation. Although VAP-1 was identified more than 15 years ago, the counterreceptor(s) for VAP-1 on leukocytes has remained unknown. Here we have identified Siglec-10 as a leukocyte ligand for VAP-1 using phage display screenings. The binding between Siglec-10 and VAP-1 was verified by different adhesion assays, and this interaction was also consistent with molecular modeling. Moreover, the interaction between Siglec-10 and VAP-1 led to increased hydrogen peroxide production, indicating that Siglec-10 serves as a substrate for VAP-1. Thus, the Siglec-10–VAP-1 interaction seems to mediate lymphocyte adhesion to endothelium and has the potential to modify the inflammatory microenvironment via the enzymatic end products. PMID:19861682

  5. Mitogen-Activated Protein Kinase (MAPK) Pathway Regulates Branching by Remodeling Epithelial Cell Adhesion

    PubMed Central

    Ihermann-Hella, Anneliis; Lume, Maria; Miinalainen, Ilkka J.; Pirttiniemi, Anniina; Gui, Yujuan; Peränen, Johan; Charron, Jean; Saarma, Mart; Costantini, Frank; Kuure, Satu

    2014-01-01

    Although the growth factor (GF) signaling guiding renal branching is well characterized, the intracellular cascades mediating GF functions are poorly understood. We studied mitogen-activated protein kinase (MAPK) pathway specifically in the branching epithelia of developing kidney by genetically abrogating the pathway activity in mice lacking simultaneously dual-specificity protein kinases Mek1 and Mek2. Our data show that MAPK pathway is heterogeneously activated in the subset of G1- and S-phase epithelial cells, and its tissue-specific deletion results in severe renal hypodysplasia. Consequently to the deletion of Mek1/2, the activation of ERK1/2 in the epithelium is lost and normal branching pattern in mutant kidneys is substituted with elongation-only phenotype, in which the epithelium is largely unable to form novel branches and complex three-dimensional patterns, but able to grow without primary defects in mitosis. Cellular characterization of double mutant epithelium showed increased E-cadherin at the cell surfaces with its particular accumulation at baso-lateral locations. This indicates changes in cellular adhesion, which were revealed by electron microscopic analysis demonstrating intercellular gaps and increased extracellular space in double mutant epithelium. When challenged to form monolayer cultures, the mutant epithelial cells were impaired in spreading and displayed strong focal adhesions in addition to spiky E-cadherin. Inhibition of MAPK activity reduced paxillin phosphorylation on serine 83 while remnants of phospho-paxillin, together with another focal adhesion (FA) protein vinculin, were augmented at cell surface contacts. We show that MAPK activity is required for branching morphogenesis, and propose that it promotes cell cycle progression and higher cellular motility through remodeling of cellular adhesions. PMID:24603431

  6. Protein O-mannosylation is crucial for E-cadherin-mediated cell adhesion.

    PubMed

    Lommel, Mark; Winterhalter, Patrick R; Willer, Tobias; Dahlhoff, Maik; Schneider, Marlon R; Bartels, Markus F; Renner-Müller, Ingrid; Ruppert, Thomas; Wolf, Eckhard; Strahl, Sabine

    2013-12-24

    In recent years protein O-mannosylation has become a focus of attention as a pathomechanism underlying severe congenital muscular dystrophies associated with neuronal migration defects. A key feature of these disorders is the lack of O-mannosyl glycans on ?-dystroglycan, resulting in abnormal basement membrane formation. Additional functions of O-mannosylation are still largely unknown. Here, we identify the essential cell-cell adhesion glycoprotein epithelial (E)-cadherin as an O-mannosylated protein and establish a functional link between O-mannosyl glycans and cadherin-mediated cell-cell adhesion. By genetically and pharmacologically blocking protein O-mannosyltransferases, we found that this posttranslational modification is essential for preimplantation development of the mouse embryo. O-mannosylation-deficient embryos failed to proceed from the morula to the blastocyst stage because of defects in the molecular architecture of cell-cell contact sites, including the adherens and tight junctions. Using mass spectrometry, we demonstrate that O-mannosyl glycans are present on E-cadherin, the major cell-adhesion molecule of blastomeres, and present evidence that this modification is generally conserved in cadherins. Further, the use of newly raised antibodies specific for an O-mannosyl-conjugated epitope revealed that these glycans are present on early mouse embryos. Finally, our cell-aggregation assays demonstrated that O-mannosyl glycans are crucial for cadherin-based cell adhesion. Our results redefine the significance of O-mannosylation in humans and other mammals, showing the immense impact of cadherins on normal as well as pathogenic cell behavior. PMID:24297939

  7. Promyelocytic Leukemia (PML) Protein Plays Important Roles in Regulating Cell Adhesion, Morphology, Proliferation and Migration

    PubMed Central

    Tang, Mei Kuen; Liang, Yong Jia; Chan, John Yeuk Hon; Wong, Sing Wan; Chen, Elve; Yao, Yao; Gan, Jingyi; Xiao, Lihai; Leung, Hin Cheung; Kung, Hsiang Fu; Wang, Hua; Lee, Kenneth Ka Ho

    2013-01-01

    PML protein plays important roles in regulating cellular homeostasis. It forms PML nuclear bodies (PML-NBs) that act like nuclear relay stations and participate in many cellular functions. In this study, we have examined the proteome of mouse embryonic fibroblasts (MEFs) derived from normal (PML+/+) and PML knockout (PML?/?) mice. The aim was to identify proteins that were differentially expressed when MEFs were incapable of producing PML. Using comparative proteomics, total protein were extracted from PML?/? and PML+/+ MEFs, resolved by two dimensional electrophoresis (2-DE) gels and the differentially expressed proteins identified by LC-ESI-MS/MS. Nine proteins (PML, NDRG1, CACYBP, CFL1, RSU1, TRIO, CTRO, ANXA4 and UBE2M) were determined to be down-regulated in PML?/? MEFs. In contrast, ten proteins (CIAPIN1, FAM50A, SUMO2 HSPB1 NSFL1C, PCBP2, YWHAG, STMN1, TPD52L2 and PDAP1) were found up-regulated. Many of these differentially expressed proteins play crucial roles in cell adhesion, migration, morphology and cytokinesis. The protein profiles explain why PML?/? and PML+/+ MEFs were morphologically different. In addition, we demonstrated PML?/? MEFs were less adhesive, proliferated more extensively and migrated significantly slower than PML+/+ MEFs. NDRG1, a protein that was down-regulated in PML?/? MEFs, was selected for further investigation. We determined that silencing NDRG1expression in PML+/+ MEFs increased cell proliferation and inhibited PML expression. Since NDRG expression was suppressed in PML?/? MEFs, this may explain why these cells proliferate more extensively than PML+/+ MEFs. Furthermore, silencing NDRG1expression also impaired TGF-?1 signaling by inhibiting SMAD3 phosphorylation. PMID:23555679

  8. Recombinant Probiotic Expressing Listeria Adhesion Protein Attenuates Listeria monocytogenes Virulence In Vitro

    PubMed Central

    Koo, Ok Kyung; Amalaradjou, Mary Anne Roshni; Bhunia, Arun K.

    2012-01-01

    Background Listeria monocytogenes, an intracellular foodborne pathogen, infects immunocompromised hosts. The primary route of transmission is through contaminated food. In the gastrointestinal tract, it traverses the epithelial barrier through intracellular or paracellular routes. Strategies to prevent L. monocytogenes entry can potentially minimize infection in high-risk populations. Listeria adhesion protein (LAP) aids L. monocytogenes in crossing epithelial barriers via the paracellular route. The use of recombinant probiotic bacteria expressing LAP would aid targeted clearance of Listeria from the gut and protect high-risk populations from infection. Methodology/Principal Findings The objective was to investigate the ability of probiotic bacteria or LAP-expressing recombinant probiotic Lactobacillus paracasei (LbpLAP) to prevent L. monocytogenes adhesion, invasion, and transwell-based transepithelial translocation in a Caco-2 cell culture model. Several wild type probiotic bacteria showed strong adhesion to Caco-2 cells but none effectively prevented L. monocytogenes infection. Pre-exposure to LbpLAP for 1, 4, 15, or 24 h significantly (P<0.05) reduced adhesion, invasion, and transepithelial translocation of L. monocytogenes in Caco-2 cells, whereas pre-exposure to parental Lb. paracasei had no significant effect. Similarly, LbpLAP pre-exposure reduced L. monocytogenes translocation by as much as 46% after 24 h. LbpLAP also prevented L. monocytogenes-mediated cell damage and compromise of tight junction integrity. Furthermore, LbpLAP cells reduced L. monocytogenes-mediated cell cytotoxicity by 99.8% after 1 h and 79% after 24 h. Conclusions/Significance Wild type probiotic bacteria were unable to prevent L. monocytogenes infection in vitro. In contrast, LbpLAP blocked adhesion, invasion, and translocation of L. monocytogenes by interacting with host cell receptor Hsp60, thereby protecting cells from infection. These data show promise for the use of recombinant probiotics in preventing L. monocytogenes infection in high-risk populations. PMID:22235279

  9. Onion yellow phytoplasma P38 protein plays a role in adhesion to the hosts.

    PubMed

    Neriya, Yutaro; Maejima, Kensaku; Nijo, Takamichi; Tomomitsu, Tatsuya; Yusa, Akira; Himeno, Misako; Netsu, Osamu; Hamamoto, Hiroshi; Oshima, Kenro; Namba, Shigetou

    2014-12-01

    Adhesins are microbial surface proteins that mediate the adherence of microbial pathogens to host cell surfaces. In Mollicutes, several adhesins have been reported in mycoplasmas and spiroplasmas. Adhesins P40 of Mycoplasma agalactiae and P89 of Spiroplasma citri contain a conserved amino acid sequence known as the Mollicutes adhesin motif (MAM), whose function in the host cell adhesion remains unclear. Here, we show that phytoplasmas, which are plant-pathogenic mollicutes transmitted by insect vectors, possess an adhesion-containing MAM that was identified in a putative membrane protein, PAM289 (P38), of the 'Candidatus Phytoplasma asteris,' OY strain. P38 homologs and their MAMs were highly conserved in related phytoplasma strains. While P38 protein was expressed in OY-infected insect and plant hosts, binding assays showed that P38 interacts with insect extract, and weakly with plant extract. Interestingly, the interaction of P38 with the insect extract depended on MAM. These results suggest that P38 is a phytoplasma adhesin that interacts with the hosts. In addition, the MAM of adhesins is important for the interaction between P38 protein and hosts. PMID:25302654

  10. Secreted Listeria adhesion protein (Lap) influences Lap-mediated Listeria monocytogenes paracellular translocation through epithelial barrier

    PubMed Central

    2013-01-01

    Background Listeria adhesion protein (Lap), an alcohol acetaldehyde dehydrogenase (lmo1634) promotes bacterial paracellular translocation through epithelial cell junctions during gastrointestinal phase of infection. Secreted Lap is critical for pathogenesis and is mediated by SecA2 system; however, if strain dependent variation in Lap secretion would affect L. monocytogenes paracellular translocation through epithelial barrier is unknown. Methods Amounts of Lap secretion were examined in clinical isolates of L. monocytogenes by cell fractionation analysis using Western blot. Quantitative reverse transcriptase PCR (qRT-PCR) was used to verify protein expression profiles. Adhesion and invasion of isolates were analyzed by in vitro Caco-2 cell culture model and paracellular translocation was determined using a trans-well model pre-seeded with Caco-2 cells. Results Western blot revealed that expression of Lap in whole cell preparation of isolates was very similar; however, cell fractionation analysis indicated variable Lap secretion among isolates. The strains showing high Lap secretion in supernatant exhibited significantly higher adhesion (3.4 - 4.8% vs 1.5 - 2.3%, P?protein transport system, SecA2. ?secA2 mutants showed significantly reduced paracellular translocation through epithelial barrier (0.48?±?0.01 vs 0.24?±?0.02, P?

  11. Formation of viscoelastic protein layers on polymeric surfaces relevant to platelet adhesion.

    PubMed

    Weber, Norbert; Wendel, Hans Peter; Kohn, Joachim

    2005-03-15

    The hemocompatibility of biomaterials is highly dependent on the adhesion and activation of platelets. Surface-adsorbed fibrinogen has a dominant role in promoting platelet adhesion to artificial surfaces by binding glycoprotein IIb-IIIa (GPIIb-IIIa), the major platelet membrane receptor. Using quartz crystal microbalance with dissipation monitoring (QCM-D), we have investigated the material-dependent binding kinetics of purified GPIIb-IIIa to polymer-adsorbed fibrinogen. The following ranking of polymer-adsorbed mass (fibrinogen and GPIIb-IIIa) to test polymers could be established: poly[desaminotyrosyl-tyrosine ethyl (DTE) carbonate]/poly(lactide-co-glycolide)>poly[DTE co-5% poly(ethylene glycol) carbonate]. The QCM-D fibrinogen adsorption data were confirmed using an immunofluorescence assay. A synthetic RGD-containing peptide, but not a control peptide, inhibited GPIIb-IIIa binding to polymer-adsorbed fibrinogen, demonstrating the specificity of binding. Importantly, the binding efficiency of purified GPIIb-IIIa to polymer-adsorbed fibrinogen correlated with increased platelet adhesion in an in vitro model. Theoretical simulations using a Voight-based model provided quantitative data on the thickness and viscoelastic properties of the polymer-adsorbed protein layers. The precision of the modeling technique was limited with respect to the shear moduli values, leading to large variations. However, the other modeling parameters showed reproducible results. The thickness of both protein layers was polymer-dependent and ranged from 5 to 35 nm and the viscosity from 0.001 to 0.005 kg/ms, whereas the protein layer densities showed little differences between the test polymers. These results suggest that material-dependent changes in the thickness and viscoelastic properties of adsorbed fibrinogen-GPIIb-IIIa layers are crucial factors in the binding behavior of platelets to biomaterials. PMID:15678483

  12. Focal adhesion proteins talin-1 and vinculin negatively affect paxillin phosphorylation and limit retroviral infection.

    PubMed

    Brown, Craig; Morham, Scott G; Walsh, Derek; Naghavi, Mojgan H

    2011-07-29

    Many of the early events in retroviral infection are not well understood, but it is known that the host cytoskeleton and signaling pathways play integral roles in various entry and post-entry processes. Focal adhesion complexes act as sites of integration for both cytoskeletal organization and integrin signaling at the cell surface. Here, we show that talin-1 and vinculin, two interacting proteins that localize in focal adhesions to mediate integrin linkage to the actin cytoskeleton, function during retroviral infection. Transient overexpression of either talin-1 or vinculin reduced the susceptibility of human cells to infection with pseudotyped human immunodeficiency virus type 1 (HIV-1) and Moloney murine leukemia virus. In contrast, transient short interfering RNA-mediated knockdown of talin-1 or vinculin increased infection by pseudotyped HIV-1 and simian immunodeficiency virus, demonstrating that the endogenous forms of these proteins also impaired retroviral infection. Talin-1 or vinculin overexpression inhibited infection by retroviruses that entered the cell by either fusion or endocytosis, while analysis of HIV-1 DNA synthesis demonstrated that the block occurred early in infection and prior to the initiation of reverse transcription. Both factors retained antiviral activity in the presence of actin or microtubule depolymerizing agents. Finally, talin-1 and vinculin expression was found to negatively influence tyrosine phosphorylation of paxillin, a major focal adhesion scaffolding protein whose transient knockdown decreased pseudotyped HIV-1 infection. Together, these findings demonstrate that talin-1 and vinculin negatively affect tyrosine phosphorylation of paxillin, a novel positive regulator of HIV-1 infection, and impose an early block to infection by distinct retroviruses. PMID:21763488

  13. A multidomain adhesion protein family expressed in Plasmodium falciparum is essential for transmission to the mosquito.

    PubMed

    Pradel, Gabriele; Hayton, Karen; Aravind, L; Iyer, Lakshminarayan M; Abrahamsen, Mitchell S; Bonawitz, Annemarie; Mejia, Cesar; Templeton, Thomas J

    2004-06-01

    The recent sequencing of several apicomplexan genomes has provided the opportunity to characterize novel antigens essential for the parasite life cycle that might lead to the development of new diagnostic and therapeutic markers. Here we have screened the Plasmodium falciparum genome sequence for genes encoding extracellular multidomain putative adhesive proteins. Three of these identified genes, named PfCCp1, PfCCp2, and PfCCp3, have multiple adhesive modules including a common Limulus coagulation factor C domain also found in two additional Plasmodium genes. Orthologues were identified in the Cryptosporidium parvum genome sequence, indicating an evolutionary conserved function. Transcript and protein expression analysis shows sexual stage-specific expression of PfCCp1, PfCCp2, and PfCCp3, and cellular localization studies revealed plasma membrane-associated expression in mature gametocytes. During gametogenesis, PfCCps are released and localize surrounding complexes of newly emerged microgametes and macrogametes. PfCCp expression markedly decreased after formation of zygotes. To begin to address PfCCp function, the PfCCp2 and PfCCp3 gene loci were disrupted by homologous recombination, resulting in parasites capable of forming oocyst sporozoites but blocked in the salivary gland transition. Our results describe members of a conserved apicomplexan protein family expressed in sexual stage Plasmodium parasites that may represent candidates for subunits of a transmission-blocking vaccine. PMID:15184503

  14. Nanometer polymer surface features: the influence on surface energy, protein adsorption and endothelial cell adhesion

    NASA Astrophysics Data System (ADS)

    Carpenter, Joseph; Khang, Dongwoo; Webster, Thomas J.

    2008-12-01

    Current small diameter (<5 mm) synthetic vascular graft materials exhibit poor long-term patency due to thrombosis and intimal hyperplasia. Tissue engineered solutions have yielded functional vascular tissue, but some require an eight-week in vitro culture period prior to implantation—too long for immediate clinical bedside applications. Previous in vitro studies have shown that nanostructured poly(lactic-co-glycolic acid) (PLGA) surfaces elevated endothelial cell adhesion, proliferation, and extracellular matrix synthesis when compared to nanosmooth surfaces. Nonetheless, these studies failed to address the importance of lateral and vertical surface feature dimensionality coupled with surface free energy; nor did such studies elicit an optimum specific surface feature size for promoting endothelial cell adhesion. In this study, a series of highly ordered nanometer to submicron structured PLGA surfaces of identical chemistry were created using a technique employing polystyrene nanobeads and poly(dimethylsiloxane) (PDMS) molds. Results demonstrated increased endothelial cell adhesion on PLGA surfaces with vertical surface features of size less than 18.87 nm but greater than 0 nm due to increased surface energy and subsequently protein (fibronectin and collagen type IV) adsorption. Furthermore, this study provided evidence that the vertical dimension of nanometer surface features, rather than the lateral dimension, is largely responsible for these increases. In this manner, this study provides key design parameters that may promote vascular graft efficacy.

  15. Measurement of adhesive forces between bacteria and protein-coated surfaces using optical tweezers

    NASA Astrophysics Data System (ADS)

    Simpson, Kathryn H.; Bowden, Gabriela; Hook, Magnus; Anvari, Bahman

    2002-05-01

    Bacterial adhesion is a primary cause of failure in implanted medical devices. Bacteria commonly found in device-related infections, such as S. aureus, have multiple cell surface adhesins which mediate specific adhesion to molecules found in extracellular matrix and blood plasma. Adhesins recognizing fibrinogen, fibronectin, collagen, and elastin molecules have been isolated in S. aureus. We have used optical tweezers to measure the adhesive force between a single bacterium and a protein-coated surface. Various concentrations of fibronectin, fibrinogen, or whole plasma were immobilized onto 10-micrometers diameter polystyrene microspheres. We optically trapped a bacterium with a titanium-sapphire laser tuned to 830 nm and contacted the cell with a coated bead. We determined the minimum force necessary to separate the cell and bead. For beads coated with fibronectin and fibrinogen, detachment force values occurred as approximate integer multiples of an estimated single bond detachment force. With plasma-coated beads, only cells lacking the fibrinogen adhesin could be detached; therefore, we believe that either this adhesin is prevalent on wilde-type cells, or it is preferentially adsorbed onto the beads. Additionally, the whole plasma detachment forces appeared random; therefore, we believe that many adhesins participate in boding to plasma.

  16. Quantum dots as bio-labels for the localization of a small plant adhesion protein

    NASA Astrophysics Data System (ADS)

    Ravindran, Sathyajith; Kim, Sunran; Martin, Rebecca; Lord, Elizabeth M.; Ozkan, Cengiz S.

    2005-01-01

    Recently, semiconducting nanoparticles have been successfully applied in live mammalian cell cultures, as alternative biological labels for multicolour imaging, by verifying known physiological processes. Here, we report the application of semiconducting nanoparticles to live plant cells in culture. Utilizing this technique, we have uncovered new knowledge regarding the localization of a plant pollen tube adhesion protein, stigma/stylar cysteine-rich adhesin (SCA). The potential of these nanoparticles is evident when the results were compared with conventional immunolocalization methods using fluorescently labelled antibodies.

  17. The Cell Adhesion Molecule Retina Cognin Is a Cell Surface Protein Disulfide Isomerase That Uses Disulfide Exchange Activity to Modulate Cell Adhesion

    Microsoft Academic Search

    Harold P. Pariser; Jun Zhang; Robert E. Hausman

    2000-01-01

    The retina cell adhesion molecule, R-cognin, shares cDNA sequence with protein disulfide isomerase (PDI) but has a different molecular size and subcellular location. We asked whether R-cognin originated from a unique PDI gene transcript or was a product of posttranscriptional processing. The 3?-terminal partial cDNA clone for R-cognin was extended by both 5? RACE and by PCR from sequence near

  18. Protein-Mediated Adhesion of the Dissimilatory Fe(III)-Reducing Bacterium Shewanella alga BrY to Hydrous Ferric Oxide

    PubMed Central

    Caccavo, Frank

    1999-01-01

    The rate and extent of bacterial Fe(III) mineral reduction are governed by molecular-scale interactions between the bacterial cell surface and the mineral surface. These interactions are poorly understood. This study examined the role of surface proteins in the adhesion of Shewanella alga BrY to hydrous ferric oxide (HFO). Enzymatic degradation of cell surface polysaccharides had no effect on cell adhesion to HFO. The proteolytic enzymes Streptomyces griseus protease and chymotrypsin inhibited the adhesion of S. alga BrY cells to HFO through catalytic degradation of surface proteins. Trypsin inhibited S. alga BrY adhesion solely through surface-coating effects. Protease and chymotrypsin also mediated desorption of adhered S. alga BrY cells from HFO while trypsin did not mediate cell desorption. Protease removed a single peptide band that represented a protein with an apparent molecular mass of 50 kDa. Chymotrypsin removed two peptide bands that represented proteins with apparent molecular masses of 60 and 31 kDa. These proteins represent putative HFO adhesion molecules. S. alga BrY adhesion was inhibited by up to 46% when cells were cultured at sub-MICs of chloramphenicol, suggesting that protein synthesis is necessary for adhesion. Proteins extracted from the surface of S. alga BrY cells inhibited adhesion to HFO by up to 41%. A number of these proteins bound specifically to HFO, suggesting that a complex system of surface proteins mediates S. alga BrY adhesion to HFO. PMID:10543817

  19. Protein-mediated adhesion of the dissimilatory Fe(III)-reducing bacterium Shewanella alga BrY to hydrous ferric oxide

    SciTech Connect

    Caccavo, F. Jr.

    1999-11-01

    The rate and extent of bacterial Fe(III) mineral reduction are governed by molecular-scale interactions between the bacterial cell surface and the mineral surface. These interactions are poorly understood. This study examined the role of surface proteins in the adhesion of Shewanella alga BrY to hydrous ferric oxide (HFO). Enzymatic degradation of cell surface polysaccharides had no effect on cell adhesion to HFO. The proteolytic enzymes Streptomyces griseus protease and chymotrypsin inhibited the adhesion of S. alga BrY cells to HFO through catalytic degradation of surface proteins. Trypsin inhibited S. alga BrY adhesion solely through surface-coating effects. Protease and chymotrypsin also mediated desorption of adhered S. alga BrY cells from HFO while trypsin did not mediate cell desorption. Protease removed a single peptide band that represented a protein with an apparent molecular mass of 50 kDa. Chymotrypsin removed two peptide bands that represented proteins with apparent molecular masses of 60 and 31 kDa. These proteins represent putative HGO adhesion molecules. A. alga BrY adhesion was inhibited by up to 46% when cells were cultured at sub-MICs of chloramphenicol, suggesting that protein synthesis is necessary for adhesion. Proteins extracted from the surface of S. alga BrY cells inhibited adhesion to HFO by up to 41%. A number of these proteins bound specifically to HFO, suggesting that a complex system of surface proteins mediates S. alga BrY adhesion to HFO.

  20. A Lipid Transfer–like Protein Is Necessary for Lily Pollen Tube Adhesion to an in Vitro Stylar Matrix

    PubMed Central

    Park, Sang-Youl; Jauh, Guang-Yuh; Mollet, Jean-Claude; Eckard, Kathleen J.; Nothnagel, Eugene A.; Walling, Linda L.; Lord, Elizabeth M.

    2000-01-01

    Flowering plants possess specialized extracellular matrices in the female organs of the flower that support pollen tube growth and sperm cell transfer along the transmitting tract of the gynoecium. Transport of the pollen tube cell and the sperm cells involves a cell adhesion and migration event in species such as lily that possess a transmitting tract epidermis in the stigma, style, and ovary. A bioassay for adhesion was used to isolate from the lily stigma/stylar exudate the components that are responsible for in vivo pollen tube adhesion. At least two stylar components are necessary for adhesion: a large molecule and a small (9 kD) protein. In combination, the two molecules induced adhesion of pollen tubes to an artificial stylar matrix in vitro. The 9-kD protein was purified, and its corresponding cDNA was cloned. This molecule shares some similarity with plant lipid transfer proteins. Immunolocalization data support its role in facilitating adhesion of pollen tubes to the stylar transmitting tract epidermis. PMID:10634914

  1. Biophysical Characterization of the Unstructured Cytoplasmic Domain of the Human Neuronal Adhesion Protein Neuroligin 3

    PubMed Central

    Paz, Aviv; Zeev-Ben-Mordehai, Tzviya; Lundqvist, Martin; Sherman, Eilon; Mylonas, Efstratios; Weiner, Lev; Haran, Gilad; Svergun, Dmitri I.; Mulder, Frans A. A.; Sussman, Joel L.; Silman, Israel

    2008-01-01

    Cholinesterase-like adhesion molecules (CLAMs) are a family of neuronal cell adhesion molecules with important roles in synaptogenesis, and in maintaining structural and functional integrity of the nervous system. Our earlier study on the cytoplasmic domain of one of these CLAMs, the Drosophila protein, gliotactin, showed that it is intrinsically unstructured in vitro. Bioinformatic analysis suggested that the cytoplasmic domains of other CLAMs are also intrinsically unstructured, even though they bear no sequence homology to each other or to any known protein. In this study, we overexpress and purify the cytoplasmic domain of human neuroligin 3, notwithstanding its high sensitivity to the Escherichia coli endogenous proteases that cause its rapid degradation. Using bioinformatic analysis, sensitivity to proteases, size exclusion chromatography, fluorescence correlation spectroscopy, analytical ultracentrifugation, small angle x-ray scattering, circular dichroism, electron spin resonance, and nuclear magnetic resonance, we show that the cytoplasmic domain of human neuroligin 3 is intrinsically unstructured. However, several of these techniques indicate that it is not fully extended, but becomes significantly more extended under denaturing conditions. PMID:18456828

  2. Spontaneous unraveling of hagfish slime thread skeins is mediated by a seawater-soluble protein adhesive.

    PubMed

    Bernards, Mark A; Oke, Isdin; Heyland, Andreas; Fudge, Douglas S

    2014-04-15

    Hagfishes are known for their ability to rapidly produce vast quantities of slime when provoked. The slime is formed via the interaction between seawater and two components released by the slime glands: mucin vesicles from gland mucous cells, which swell and rupture in seawater to form a network of mucus strands, and intermediate filament-rich threads, which are produced within gland thread cells as tightly coiled bundles called skeins. A previous study showed that the unraveling of skeins from Atlantic hagfish (Myxine glutinosa) requires both the presence of mucins and hydrodynamic mixing. In contrast, skeins from Pacific hagfish (Eptatretus stoutii) unravel in the absence of both mucins and mixing. We tested the hypothesis that spontaneous unraveling of E. stoutii skeins is triggered by the dissolution of a seawater-soluble protein adhesive and the release of stored strain energy within the coiled thread. Here we show that, as predicted by this hypothesis, unraveling can be initiated by a protease under conditions in which unraveling does not normally occur. We also demonstrate, using high resolution scanning electron microscopy, that the treatment of skeins with solutions that cause unraveling also leads to the disappearance of surface and inter-thread features that remain when skeins are washed with stabilizing solutions. Our study provides a mechanism for the deployment of thread skeins in Pacific hagfish slime, and raises the possibility of producing novel biomimetic protein adhesives that are salt, temperature and kosmotrope sensitive. PMID:24744422

  3. Protein-mediated Adhesion of Lactobacillus fermentum Strain 737 to Mouse Stomach Squamous Epithelium

    Microsoft Academic Search

    PATRICIA L. CONWAY; STAFFAN KJELLEBERG

    1989-01-01

    The mechanism of adhesion of Lactobacillus fermentum strain 737 to mouse stomach squamous epithelium was investigated. Adhesion inhibition tests involving chelators, monosaccharides, periodate and concanavalin A and the use of bacteria grown in the presence of tunicamycin failed to clarify the adhesive mechanism. Washed bacterial cells had reduced adhesive capacity, except in the presence of spent broth culture supernatant fraction

  4. High Affinity Neurexin Binding to Cell Adhesion G-protein-coupled Receptor CIRL1/Latrophilin-1 Produces an Intercellular Adhesion Complex*

    PubMed Central

    Boucard, Antony A.; Ko, Jaewon; Südhof, Thomas C.

    2012-01-01

    The G-protein-coupled receptor CIRL1/latrophilin-1 (CL1) and the type-1 membrane proteins neurexins represent distinct neuronal cell adhesion molecules that exhibit no similarities except for one common function: both proteins are receptors for ?-latrotoxin, a component of black widow spider venom that induces massive neurotransmitter release at synapses. Unexpectedly, we have now identified a direct binding interaction between the extracellular domains of CL1 and neurexins that is regulated by alternative splicing of neurexins at splice site 4 (SS4). Using saturation binding assays, we showed that neurexins lacking an insert at SS4 bind to CL1 with nanomolar affinity, whereas neurexins containing an insert at SS4 are unable to bind. CL1 competed for neurexin binding with neuroligin-1, a well characterized neurexin ligand. The extracellular sequences of CL1 contain five domains (lectin, olfactomedin-like, serine/threonine-rich, hormone-binding, and G-protein-coupled receptor autoproteolysis-inducing (GAIN) domains). Of these domains, the olfactomedin-like domain mediates neurexin binding as shown by deletion mapping. Cell adhesion assays using cells expressing neurexins and CL1 revealed that their interaction produces a stable intercellular adhesion complex, indicating that their interaction can be trans-cellular. Thus, our data suggest that CL1 constitutes a novel ligand for neurexins that may be localized postsynaptically based on its well characterized interaction with intracellular SH3 and multiple ankyrin repeats adaptor proteins (SHANK) and could form a trans-synaptic complex with presynaptic neurexins. PMID:22262843

  5. Podocalyxin Is a Novel Polysialylated Neural Adhesion Protein with Multiple Roles in Neural Development and Synapse Formation

    Microsoft Academic Search

    Nathalia Vitureira; Rosa Andrés; Esther Pérez-Martínez; Albert Martínez; Ana Bribián; Juan Blasi; Shierley Chelliah; Guillermo López-Doménech; Fernando de Castro; Ferran Burgaya; Kelly McNagny; Eduardo Soriano; Antoni L. Andreu

    2010-01-01

    Neural development and plasticity are regulated by neural adhesion proteins, including the polysialylated form of NCAM (PSA-NCAM). Podocalyxin (PC) is a renal PSA-containing protein that has been reported to function as an anti-adhesin in kidney podocytes. Here we show that PC is widely expressed in neurons during neural development. Neural PC interacts with the ERM protein family, and with NHERF1\\/2

  6. Recombinant mussel adhesive protein fp-5 (MAP fp-5) as a bulk bioadhesive and surface coating material.

    PubMed

    Choi, Yoo Seong; Kang, Dong Gyun; Lim, Seonghye; Yang, Yun Jung; Kim, Chang Sup; Cha, Hyung Joon

    2011-08-01

    Mussel adhesive proteins (MAPs) attach to all types of inorganic and organic surfaces, even in wet environments. MAP of type 5 (fp-5), in particular, has been considered as a key adhesive material. However, the low availability of fp-5 has hampered its biochemical characterization and practical applications. Here, soluble recombinant fp-5 is mass-produced in Escherichia coli. Tyrosinase-modified recombinant fp-5 showed ?1.11 MPa adhesive shear strength, which is the first report of a bulk-scale adhesive force measurement for purified recombinant of natural MAP type. Surface coatings were also performed through simple dip-coating of various objects. In addition, complex coacervate using recombinant fp-5 and hyaluronic acid was prepared as an efficient adhesive formulation, which greatly improved the bulk adhesive strength. Collectively, it is expected that this work will enhance basic understanding of mussel adhesion and that recombinant fp-5 can be successfully used as a realistic bulk-scale bioadhesive and an efficient surface coating material. PMID:21770718

  7. The Desmosomal Armadillo Protein Plakoglobin Regulates Prostate Cancer Cell Adhesion and Motility through Vitronectin-Dependent Src Signaling

    PubMed Central

    Desai, Bhushan V.; Mirzoeva, Salida; Yang, Ximing J.; Green, Kathleen J.; Pelling, Jill C.

    2012-01-01

    Plakoglobin (PG) is an armadillo protein that associates with both classic and desmosomal cadherins, but is primarily concentrated in mature desmosomes in epithelia. While reduced levels of PG have been reported in localized and hormone refractory prostate tumors, the functional significance of these changes is unknown. Here we report that PG expression is reduced in samples of a prostate tumor tissue array and inversely correlated with advancing tumor potential in 7 PCa cell lines. Ectopically expressed PG enhanced intercellular adhesive strength, and attenuated the motility and invasion of aggressive cell lines, whereas silencing PG in less tumorigenic cells had the opposite effect. PG also regulated cell-substrate adhesion and motility through extracellular matrix (ECM)-dependent inhibition of Src kinase, suggesting that PG’s effects were not due solely to increased intercellular adhesion. PG silencing resulted in elevated levels of the ECM protein vitronectin (VN), and exposing PG-expressing cells to VN induced Src activity. Furthermore, increased VN levels and Src activation correlated with diminished expression of PG in patient tissues. Thus, PG may inhibit Src by keeping VN low. Our results suggest that loss of intercellular adhesion due to reduced PG expression might be exacerbated by activation of Src through a PG-dependent mechanism. Furthermore, PG down-regulation during PCa progression could contribute to the known VN-dependent promotion of PCa invasion and metastasis, demonstrating a novel functional interaction between desmosomal cell-cell adhesion and cell-substrate adhesion signaling axes in prostate cancer. PMID:22860065

  8. rOmpA is a critical protein for the adhesion of Rickettsia rickettsii to host cells

    Microsoft Academic Search

    Han Li; David H Walker

    1998-01-01

    rOmpA and rOmpB are immunodominant, surface-exposed proteins ofRickettsia rickettsii.Prior evidence suggests that adhesion ofR. rickettsiito the host cell is mediated by a rickettsial protein. Five monoclonal antibodies to rOmpA, five to rOmpB, and one to the rickettsial lipopolysaccharide (LPS) were tested for inhibition of rickettsial attachment. All the monoclonal antibodies to rOmpA inhibited adhesion of rickettsiae to the L-929 cells

  9. SH2 Domain-Containing Protein Tyrosine Phosphatase 2 and Focal Adhesion Kinase Protein Interactions Regulate Pulmonary Endothelium Barrier Function.

    PubMed

    Chichger, Havovi; Braza, Julie; Duong, Huetran; Harrington, Elizabeth O

    2015-06-01

    Enhanced protein tyrosine phosphorylation is associated with changes in vascular permeability through formation and dissolution of adherens junctions and regulation of stress fiber formation. Inhibition of the protein tyrosine phosphorylase SH2 domain-containing protein tyrosine phosphatase 2 (SHP2) increases tyrosine phosphorylation of vascular endothelial cadherin and ?-catenin, resulting in disruption of the endothelial monolayer and edema formation in the pulmonary endothelium. Vascular permeability is a hallmark of acute lung injury (ALI); thus, enhanced SHP2 activity offers potential therapeutic value for the pulmonary vasculature in diseases such as ALI, but this has not been characterized. To assess whether SHP2 activity mediates protection against edema in the endothelium, we assessed the effect of molecular activation of SHP2 on lung endothelial barrier function in response to the edemagenic agents LPS and thrombin. Both LPS and thrombin reduced SHP2 activity, correlated with decreased focal adhesion kinase (FAK) phosphorylation (Y(397) and Y(925)) and diminished SHP2 protein-protein associations with FAK. Overexpression of constitutively active SHP2 (SHP2(D61A)) enhanced baseline endothelial monolayer resistance and completely blocked LPS- and thrombin-induced permeability in vitro and significantly blunted pulmonary edema formation induced by either endotoxin (LPS) or Pseudomonas aeruginosa exposure in vivo. Chemical inhibition of FAK decreased SHP2 protein-protein interactions with FAK concomitant with increased permeability; however, overexpression of SHP2(D61A) rescued the endothelium and maintained FAK activity and FAK-SHP2 protein interactions. Our data suggest that SHP2 activation offers the pulmonary endothelium protection against barrier permeability mediators downstream of the FAK signaling pathway. We postulate that further studies into the promotion of SHP2 activation in the pulmonary endothelium may offer a therapeutic approach for patients suffering from ALI. PMID:25317600

  10. Nanostructured Biointerfaces: Nanoarchitectonics of Thermoresponsive Polymer Brushes Impact Protein Adsorption and Cell Adhesion.

    PubMed

    Psarra, Evmorfia; König, Ulla; Ueda, Yuichiro; Bellmann, Cornelia; Janke, Andreas; Bittrich, Eva; Eichhorn, Klaus-J; Uhlmann, Petra

    2015-06-17

    Controlling the reversibility, quantity, and extent of biomolecule interaction at interfaces has a significant relevance for biomedical and biotechnological applications, because protein adsorption is always the first step when a solid surface gets in contact with a biological fluid. Polymer brushes, composed of end-tethered linear polymers with sufficient grafting density, are very promising to control and alter interactions with biological systems because of their unique structure and distinct collaborative response to environmental changes. We studied protein adsorption and cell adhesion at polymer brush substrates which consisted of poly(N-isopropylacrylamide) (PNIPAAm), having a lower critical solution temperature (LCST), to control bioadsorptive processes by changing the environmental temperature. Preparing the PNIPAAm brushes by the "grafting-to"-method two differently synthesized PNIPAAm polymers were used, at which one possessed an additional hydrophobic terminal headgroup. It is known that hydrophobic moieties can influence protein adsorption significantly. The films were comprehensively analyzed by in situ spectroscopic ellipsometry, contact angle measurements, streaming potential, and atomic force microscopy. Our study was mainly focused on the investigation of the fibrinogen (FGN) adsorption responsiveness both on homo polymer PNIPAAm brushes with and without the hydrophobic terminal functionalization, and further on binary brushes made of the polyelectrolyte poly(acrylic acid) (PAA) and one of the prior described two PNIPAAm species. The results show that the terminal hydrophobic modification of PNIPAAm has a considerable impact on wettability, LCST, and morphology of the homo and the binary brush systems, which consequently led to an alteration of FGN adsorption. By using binary PNIPAAm-PAA brushes with different composition it was possible to induce stimuli dependent FGN adsorption with a considerable amplified switching effect by introducing a hydrophobic terminal residue to PNIPAAm. Cell adhesion studies with human mesenchymal stem cells reflected the results of the FGN adsorption. PMID:25651080

  11. Cannabinoid inhibits HIV-1 Tat-stimulated adhesion of human monocyte-like cells to extracellular matrix proteins

    PubMed Central

    Raborn, Erinn S.; Jamerson, Melissa; Marciano-Cabral, Francine; Cabral, Guy A.

    2014-01-01

    Aims The aim of this study was to assess the effect of select cannabinoids on human immunodeficiency virus type 1 (HIV-1) transactivating (Tat) protein-enhanced monocyte-like cell adhesion to proteins of the extracellular matrix (ECM). Main Methods Collagen IV, laminin, or an ECM gel were used to construct extracellular matrix layers. Human U937 monocyte-like cells were exposed to Tat in the presence of ?9-tetrahydrocannabinol (THC), CP55,940, and other select cannabinoids. Cell attachment to ECM proteins was assessed using an adhesion assay. Key findings THC and CP55,940 inhibited Tat-enhanced attachment of U937 cells to ECM proteins in a mode that was linked to the cannabinoid receptor type 2 (CB2R). The cannabinoid treatment of Tat-activated U937 cells was associated with altered ?1-integrin expression and distribution of polymerized actin, suggesting a modality by which these cannabinoids inhibited adhesion to the ECM. Significance The blood-brain barrier (BBB) is a complex structure that is composed of cellular elements and an extracellular matrix (ECM). HIV-1 Tat promotes transmigration of monocytes across this barrier, a process that includes interaction with ECM proteins. The results indicate that cannabinoids that activate the CB2R inhibit the ECM adhesion process. Thus, this receptor has potential to serve as a therapeutic agent for ablating neuroinflammation associated with HIV-elicited influx of monocytes across the BBB. PMID:24742657

  12. Rapid adhesion and spread of non-adherent colon cancer Colo201 cells induced by the protein kinase inhibitors, K252a and KT5720 and suppression of the adhesion by the immunosuppressants FK506 and cyclosporin A.

    PubMed

    Mohri, T; Kameshita, I; Suzuki, S; Hioki, K; Tokunaga, R; Takatani, S

    1998-10-01

    We examined alterations in cell morphology and expression of adhesion molecules in response to a general protein kinase inhibitor K252a treatment of non-adherent colon adenocarcinoma Colo201 cells. K252a induced rapid cell adhesion and spreading with concomitant formation of actin stress fibers. A protein kinase A inhibitor KT5720 also induced cell adhesion, but the rate of spread was slower than that seen with K252a. These adhesions were mediated by integrin molecules since cell adhesion required Mg2+, Mn2+ or Ca2+, and was inhibited by monoclonal antibodies for integrins alpha2 and beta1. Indirect immunofluorescence microscopic observations revealed that integrin alpha2 and beta1 molecules in K252a-treated cells were concentrated at sites of focal adhesion, but expressions of integrin molecules were not modulated. Tyrosine phosphorylation of focal adhesion kinase (FAK) and paxillin increased during K252a- or KT5720-induced cell adhesion. Immunosuppressants FK506 and cyclosporin A suppressed the K252a-induced cell adhesion and abolished tyrosine phosphorylation of cellular proteins including FAK and paxillin. Furthermore, W7 and calmidazolium, inhibitors of calmodulin, also inhibited the cell adhesion. Based on findings that FK506 and cyclosporin A are inhibitors of the calcium calmodulin-dependent protein phosphatase, calcineurin, this phosphatase may regulate integrin-dependent cell adhesion and spread of Colo201 cells. This Colo201 cell model provides a pertinent system for studying molecules involved in signal transduction pathways and can shed light on mechanisms of metastasis and invasion of colon carcinoma cells. PMID:9872566

  13. The adhesion of mussel foot protein-3 to TiO2 surfaces: the effect of pH

    PubMed Central

    Yu, Jing; Wei, Wei; Menyo, Matthew S.; Masic, Admir; Waite, J. Herbert; Israelachvili, Jacob N.

    2013-01-01

    The underwater adhesion of marine mussels relies on mussel foot proteins (mfps) rich in the catecholic amino acid 3, 4-dihydroxyphenylalanine (Dopa). As a side-chain, Dopa is capable of strong bidentate interactions with a variety of surfaces, including many minerals and metal oxides. Titanium is among the most widely used medical implant material and quickly forms a TiO2 passivation layer under physiological conditions. Understanding the binding mechanism of Dopa to TiO2 surfaces is therefore of considerable theoretical and practical interest. Using a surface forces apparatus, we explored the force-distance profiles and adhesion energies of mussel foot protein 3 (mfp-3) to TiO2 surfaces at three different pHs (pH3, 5.5 and 7.5). At pH3, mfp-3 showed the strongest adhesion force on TiO2, with an adhesion energy of ~ ?7.0 mJ/m2. Increasing the pH gives rise to two opposing effects: (1) increased oxidation of Dopa, thus decreasing availability for the Dopa-mediated adhesion, and (2) increased bidentate Dopa-Ti coordination, leading to the further stabilization of the Dopa group and thus an increasing of adhesion force. Both effects were reflected in the resonance-enhanced Raman spectra obtained at the three deposition pHs. The two competing effects give rise to a higher adhesion force of mfp-3 on TiO2 surface at pH 7.5 than at pH 5.5. Our results suggest that Dopa-containing proteins and synthetic polymers have great potential as coating materials for medical implant materials, particularly if redox activity can be controlled. PMID:23452271

  14. Fabrication of three-dimensional multi-protein microstructures for cell migration and adhesion enhancement.

    PubMed

    Da Sie, Yong; Li, Yi-Cheng; Chang, Nan-Shan; Campagnola, Paul J; Chen, Shean-Jen

    2015-02-01

    In this study, three-dimensional (3D) multi-component microstructures were precisely fabricated via multiphoton excited photochemistry using a femtosecond laser direct-writing system with proposed repetition positioning and vector scanning techniques. Extracellular matrix (ECM) proteins, such as fibronectin (FN), are difficult to stack and form 3D structures larger than several-hundred microns in height due to the nature of their protein structure. Herein, to fabricate complex 3D microstructures with FN, a 3D scaffold was designed and formed from bovine serum albumin (BSA), after which human FN was inserted at specific locations on the BSA scaffold; in this manner, the fabricated ECM microstructure can guide cells in a 3D environment. A human breast cancer cell line, MDA-MB-231, was used to investigate the behavior of cell migration and adhesion on the fabricated human FN and BSA protein structures. Experimental results indicate that many cells are not able to attach or climb on a 3D structure's inclined plane without FN support; hence, the influence of cell growth in a 3D context with FN should being taken into consideration. This 3D multi-protein fabrication technique holds potential for cell studies in designed complex 3D ECM scaffolds. PMID:25780738

  15. Cyclic Guanosine Monophosphate-dependent Protein Kinase I Promotes Adhesion of Primary Vascular Smooth Muscle Cells

    PubMed Central

    Lukowski, Robert; Linder, Stefan; Traidl-Hoffmann, Claudia; Hengst, Ludger; Hofmann, Franz; Feil, Robert

    2008-01-01

    The cyclic guanosine monophosphate (cGMP)/cGMP-dependent protein kinase type I (cGKI) pathway regulates many cellular functions. The current study shows that 8-Br-cGMP stimulates the number of attached primary but not that of subcultured murine vascular smooth muscle cells (VSMCs). These effects of 8-Br-cGMP require the presence of cGKI. In agreement with previous studies, cGKI inhibited the number of cells in repeatedly passaged murine VSMCs. Activation of the cGMP/cGKI pathway in freshly isolated primary VSMCs slightly decreased apoptosis and strongly increased cell adhesion. The stimulation of cell adhesion by cGKI involves an inhibition of the RhoA/Rho kinase pathway and increased exposure of ?1 and ?3 integrins on the cell surface. Together, these results identify a novel proadhesive function of cGMP/cGKI signaling in primary VSMCs and suggest that the opposing effects of this pathway on VSMC number depend on the phenotypic context of the cells. PMID:18685080

  16. Syntenin-1 and ezrin proteins link activated leukocyte cell adhesion molecule to the actin cytoskeleton.

    PubMed

    Tudor, Cicerone; te Riet, Joost; Eich, Christina; Harkes, Rolf; Smisdom, Nick; Bouhuijzen Wenger, Jessica; Ameloot, Marcel; Holt, Matthew; Kanger, Johannes S; Figdor, Carl G; Cambi, Alessandra; Subramaniam, Vinod

    2014-05-01

    Activated leukocyte cell adhesion molecule (ALCAM) is a type I transmembrane protein member of the immunoglobulin superfamily of cell adhesion molecules. Involved in important pathophysiological processes such as the immune response, cancer metastasis, and neuronal development, ALCAM undergoes both homotypic interactions with other ALCAM molecules and heterotypic interactions with the surface receptor CD6 expressed at the T cell surface. Despite biochemical and biophysical evidence of a dynamic association between ALCAM and the actin cytoskeleton, no detailed information is available about how this association occurs at the molecular level. Here, we exploit a combination of complementary microscopy techniques, including FRET detected by fluorescence lifetime imaging microscopy and single-cell force spectroscopy, and we demonstrate the existence of a preformed ligand-independent supramolecular complex where ALCAM stably interacts with actin by binding to syntenin-1 and ezrin. Interaction with the ligand CD6 further enhances these multiple interactions. Altogether, our results propose a novel biophysical framework to understand the stabilizing role of the ALCAM supramolecular complex engaged to CD6 during dendritic cell-T cell interactions and provide novel information on the molecular players involved in the formation and signaling of the immunological synapse at the dendritic cell side. PMID:24662291

  17. Vascular adhesion protein-1 promotes liver inflammation and drives hepatic fibrosis

    PubMed Central

    Weston, Chris J.; Shepherd, Emma L.; Claridge, Lee C.; Rantakari, Pia; Curbishley, Stuart M.; Tomlinson, Jeremy W.; Hubscher, Stefan G.; Reynolds, Gary M.; Aalto, Kristiina; Anstee, Quentin M.; Jalkanen, Sirpa; Salmi, Marko; Smith, David J.; Day, Christopher P.; Adams, David H.

    2014-01-01

    Nonalcoholic fatty liver disease (NAFLD) encompasses a range of manifestations, including steatosis and cirrhosis. Progressive disease is characterized by hepatic leukocyte accumulation in the form of steatohepatitis. The adhesion molecule vascular adhesion protein-1 (VAP-1) is a membrane-bound amine oxidase that promotes leukocyte recruitment to the liver, and the soluble form (sVAP-1) accounts for most circulating monoamine oxidase activity, has insulin-like effects, and can initiate oxidative stress. Here, we determined that hepatic VAP-1 expression is increased in patients with chronic liver disease and that serum sVAP-1 levels are elevated in patients with NAFLD compared with those in control individuals. In 4 murine hepatic injury models, an absence or blockade of functional VAP-1 reduced inflammatory cell recruitment to the liver and attenuated fibrosis. Moreover, disease was reduced in animals expressing a catalytically inactive form of VAP-1, implicating enzyme activity in the disease pathogenesis. Within the liver, hepatic stromal cells expressed functional VAP-1, and evaluation of cultured cells revealed that sVAP-1 promotes leukocyte migration through catalytic generation of ROS, which depended on VAP-1 enzyme activity. VAP-1 enhanced stromal cell spreading and wound closure and modulated expression of profibrotic genes. Together, these results link the amine oxidase activity of VAP-1 with hepatic inflammation and fibrosis and suggest that targeting VAP-1 has therapeutic potential for NAFLD and other chronic fibrotic liver diseases. PMID:25562318

  18. Vascular adhesion protein-1 promotes liver inflammation and drives hepatic fibrosis.

    PubMed

    Weston, Chris J; Shepherd, Emma L; Claridge, Lee C; Rantakari, Pia; Curbishley, Stuart M; Tomlinson, Jeremy W; Hubscher, Stefan G; Reynolds, Gary M; Aalto, Kristiina; Anstee, Quentin M; Jalkanen, Sirpa; Salmi, Marko; Smith, David J; Day, Christopher P; Adams, David H

    2015-02-01

    Nonalcoholic fatty liver disease (NAFLD) encompasses a range of manifestations, including steatosis and cirrhosis. Progressive disease is characterized by hepatic leukocyte accumulation in the form of steatohepatitis. The adhesion molecule vascular adhesion protein-1 (VAP-1) is a membrane-bound amine oxidase that promotes leukocyte recruitment to the liver, and the soluble form (sVAP-1) accounts for most circulating monoamine oxidase activity, has insulin-like effects, and can initiate oxidative stress. Here, we determined that hepatic VAP-1 expression is increased in patients with chronic liver disease and that serum sVAP-1 levels are elevated in patients with NAFLD compared with those in control individuals. In 4 murine hepatic injury models, an absence or blockade of functional VAP-1 reduced inflammatory cell recruitment to the liver and attenuated fibrosis. Moreover, disease was reduced in animals expressing a catalytically inactive form of VAP-1, implicating enzyme activity in the disease pathogenesis. Within the liver, hepatic stromal cells expressed functional VAP-1, and evaluation of cultured cells revealed that sVAP-1 promotes leukocyte migration through catalytic generation of ROS, which depended on VAP-1 enzyme activity. VAP-1 enhanced stromal cell spreading and wound closure and modulated expression of profibrotic genes. Together, these results link the amine oxidase activity of VAP-1 with hepatic inflammation and fibrosis and suggest that targeting VAP-1 has therapeutic potential for NAFLD and other chronic fibrotic liver diseases. PMID:25562318

  19. Adhesive Properties of YapV and Paralogous Autotransporter Proteins of Yersinia pestis.

    PubMed

    Nair, Manoj K M; De Masi, Leon; Yue, Min; Galván, Estela M; Chen, Huaiqing; Wang, Fang; Schifferli, Dieter M

    2015-05-01

    Yersinia pestis is the causative agent of plague. This bacterium evolved from an ancestral enteroinvasive Yersinia pseudotuberculosis strain by gene loss and acquisition of new genes, allowing it to use fleas as transmission vectors. Infection frequently leads to a rapidly lethal outcome in humans, a variety of rodents, and cats. This study focuses on the Y. pestis KIM yapV gene and its product, recognized as an autotransporter protein by its typical sequence, outer membrane localization, and amino-terminal surface exposure. Comparison of Yersinia genomes revealed that DNA encoding YapV or each of three individual paralogous proteins (YapK, YapJ, and YapX) was present as a gene or pseudogene in a strain-specific manner and only in Y. pestis and Y. pseudotuberculosis. YapV acted as an adhesin for alveolar epithelial cells and specific extracellular matrix (ECM) proteins, as shown with recombinant Escherichia coli, Y. pestis, or purified passenger domains. Like YapV, YapK and YapJ demonstrated adhesive properties, suggesting that their previously related in vivo activity is due to their capacity to modulate binding properties of Y. pestis in its hosts, in conjunction with other adhesins. A differential host-specific type of binding to ECM proteins by YapV, YapK, and YapJ suggested that these proteins participate in broadening the host range of Y. pestis. A phylogenic tree including 36 Y. pestis strains highlighted an association between the gene profile for the four paralogous proteins and the geographic location of the corresponding isolated strains, suggesting an evolutionary adaption of Y. pestis to specific local animal hosts or reservoirs. PMID:25690102

  20. Novel Pyridazinone Inhibitors for Vascular Adhesion Protein-1 (VAP-1): Old target – New Inhibition Mode

    PubMed Central

    Bligt-Lindén, Eva; Pihlavisto, Marjo; Szatmári, István; Otwinowski, Zbyszek; Smith, David J.; Lázár, László; Fülöp, Ferenc; Salminen, Tiina A.

    2014-01-01

    Vascular adhesion protein-1 (VAP-1) is a primary amine oxidase and a drug target for inflammatory and vascular diseases. Despite extensive attempts to develop potent, specific and reversible inhibitors of its enzyme activity, the task has proven challenging. Here we report the synthesis, inhibitory activity and molecular binding mode of novel pyridazinone inhibitors, which show specificity for VAP-1 over monoamine and diamine oxidases. The crystal structures of three inhibitor-VAP-1 complexes show that these compounds bind reversibly into a unique binding site in the active site channel. Though they are good inhibitors of human VAP-1, they do not inhibit rodent VAP-1 well. To investigate this further, we used homology modeling and structural comparison to identify amino acid differences, which explain the species-specific binding properties. Our results prove the potency and specificity of these new inhibitors and the detailed characterization of their binding mode is of importance for further development of VAP-1 inhibitors. PMID:24304424

  1. Diamagnetic levitation causes changes in the morphology, cytoskeleton, and focal adhesion proteins expression in osteocytes.

    PubMed

    Qian, A R; Wang, L; Gao, X; Zhang, W; Hu, L F; Han, J; Li, J B; Di, S M; Shang, Peng

    2012-01-01

    Diamagnetic levitation technology is a novel simulated weightless technique and has recently been applied in life-science research. We have developed a superconducting magnet platform with large gradient high magnetic field (LG-HMF), which can provide three apparent gravity levels, namely, ?g (diamagnetic levitation), 1g, and 2g for diamagnetic materials. In this study, the effects of LG-HMF on the activity, morphology, and cytoskeleton (actin filament, microtubules, and vimentin intermediate filaments) in osteocyte - like cell line MLO-Y4 were detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) methods, hematoxylin-eosin (HE) staining, and laser scanning confocal microscopy (LSCM), respectively. The changes induced by LG-HMF in distribution and expression of focal adhesion (FA) proteins, including vinculin, paxillin, and talin in MLO-Y4 were determined by LSCM and Western blotting. The results showed that LG-HMF produced by superconducting magnet had no lethal effects on MLO-Y4. Compared to control, diamagnetic levitation (?g) affected MLO-Y4 morphology, nucleus size, cytoskeleton architecture, and FA proteins distribution and expression. The study indicates that osteocytes are sensitive to altered gravity and FA proteins (vinculin, paxillin, and talin) may be involved in osteocyte mechanosensation. The diamagnetic levitation may be a novel ground-based space-gravity simulator and can be used for biological experiment at cellular level. PMID:21216704

  2. Protein kinase C delta regulates neural cell adhesion molecule polysialylation state in the rat brain.

    PubMed

    Gallagher, H C; Murphy, K J; Foley, A G; Regan, C M

    2001-04-01

    Polysialylation of neural cell adhesion molecule (NCAM PSA) modulates cell-cell homophilic binding and signalling during brain development and the remodelling of discrete brain regions in the adult. Following learning, a transient increase in the frequency of polysialylated neurones occurs in the dentate gyrus of the hippocampal formation, and this has been correlated with the selective retention and/or elimination of synapses that are transiently overproduced during memory consolidation. We now demonstrate that protein kinase C delta (PKCdelta) negatively regulates polysialyltransferase activity in the rat brain during development and also in the hippocampus during memory consolidation, where its down-regulation in the Golgi membrane fraction coincides with the transient increase in NCAM PSA expression. Decreased expression of PKCdelta was also observed in the hippocampus of rats reared in a complex environment and this directly contrasted the significant increase in frequency of hippocampal polysialylated neurones observed in these animals. These effects were isoform-specific as no change in total PKC enzyme activity was detected during memory consolidation and complex environment rearing had no effect on the hippocampal expression of PKCalpha, beta, gamma or epsilon. By sequential immunoprecipitation and immunoblot analysis, phosphorylation of polysialyltransferase protein(s) was (were) demonstrated to occur on both serine and tyrosine residues and this was associated with decreased enzyme activity. Moreover, a similar experimental approach revealed the degree of PKCdelta co-precipitation with polysialyltransferase protein(s) to be inversely correlated with polysialyltransferase activity. These findings support in vitro evidence indicating PKCdelta to regulate polysialyltransferase activity and NCAM polysialylation state. PMID:11299305

  3. Adhesive strength and curing rate of marine mussel protein extracts on porcine small intestinal submucosa q

    E-print Network

    Shi, Riyi

    , butyl or octyl cyanoacrylate adhesives were determined. Although joints bonded using ethyl cyanoacrylate Surgical adhesives are increasingly being used in soft tissue repair as fasteners and sealants because [40] reported that the mussel adhesive formed weak bonds. These investigators used distinctly 1742

  4. Pathogenic Naegleria fowleri and non-pathogenic Naegleria lovaniensis exhibit differential adhesion to, and invasion of, extracellular matrix proteins.

    PubMed

    Jamerson, Melissa; da Rocha-Azevedo, Bruno; Cabral, Guy A; Marciano-Cabral, Francine

    2012-03-01

    Naegleria fowleri and Naegleria lovaniensis are closely related free-living amoebae found in the environment. N. fowleri causes primary amoebic meningoencephalitis (PAM), a rapidly fatal disease of the central nervous system, while N. lovaniensis is non-pathogenic. N. fowleri infection occurs when the amoebae access the nasal passages, attach to the nasal mucosa and its epithelial lining, and migrate to the brain. This process involves interaction with components of the host extracellular matrix (ECM). Since the ability to invade tissues can be a characteristic that distinguishes pathogenic from non-pathogenic amoebae, the objective of this study was to assess adhesion to, and invasion of, the ECM by these two related but distinct Naegleria species. N. fowleri exhibited a higher level of adhesion to the ECM components laminin-1, fibronectin and collagen I. Scanning electron microscopy revealed that N. fowleri attached on ECM substrata exhibited a spread-out appearance that included the presence of focal adhesion-like structures. Western immunoblotting revealed two integrin-like proteins for both species, but one of these, with a molecular mass of approximately 70 kDa, was detected at a higher level in N. fowleri. Confocal microscopy indicated that the integrin-like proteins co-localized to the focal adhesion-like structures. Furthermore, anti-integrin antibody decreased adhesion of N. fowleri to ECM components. Finally, N. fowleri disrupted 3D ECM scaffolds, while N. lovaniensis had a minimal effect. Collectively, these results indicate a distinction in adhesion to, and invasion of, ECM proteins between N. fowleri and N. lovaniensis. PMID:22222499

  5. Proteinaceous determinants of surface colonization in bacteria: bacterial adhesion and biofilm formation from a protein secretion perspective

    PubMed Central

    Chagnot, Caroline; Zorgani, Mohamed A.; Astruc, Thierry; Desvaux, Mickaël

    2013-01-01

    Bacterial colonization of biotic or abiotic surfaces results from two quite distinct physiological processes, namely bacterial adhesion and biofilm formation. Broadly speaking, a biofilm is defined as the sessile development of microbial cells. Biofilm formation arises following bacterial adhesion but not all single bacterial cells adhering reversibly or irreversibly engage inexorably into a sessile mode of growth. Among molecular determinants promoting bacterial colonization, surface proteins are the most functionally diverse active components. To be present on the bacterial cell surface, though, a protein must be secreted in the first place. Considering the close association of secreted proteins with their cognate secretion systems, the secretome (which refers both to the secretion systems and their protein substrates) is a key concept to apprehend the protein secretion and related physiological functions. The protein secretion systems are here considered in light of the differences in the cell-envelope architecture between diderm-LPS (archetypal Gram-negative), monoderm (archetypal Gram-positive) and diderm-mycolate (archetypal acid-fast) bacteria. Besides, their cognate secreted proteins engaged in the bacterial colonization process are regarded from single protein to supramolecular protein structure as well as the non-classical protein secretion. This state-of-the-art on the complement of the secretome (the secretion systems and their cognate effectors) involved in the surface colonization process in diderm-LPS and monoderm bacteria paves the way for future research directions in the field. PMID:24133488

  6. Focal adhesion kinase regulates the phosphorylation protein tyrosine phosphatase-? at Tyr789 in breast cancer cells.

    PubMed

    Fang, Xu-Qian; Liu, Xiang-Fan; Yao, Ling; Chen, Chang-Qiang; Lin, Jia-Fei; Gu, Zhi-Dong; Ni, Pei-Hua; Zheng, Xin-Min; Fan, Qi-Shi

    2015-06-01

    Protein tyrosine phosphatase (PTP)?? regulates the phosphorylation of focal adhesion kinase (FAK), which is important in cellular signal transduction and integration of proteins. It has been demonstrated that a FAK?Del33 mutation (deletion of exon 33; KF437463) in breast cancer tissues regulates cell migration through FAK/Src signaling activation. However, the detailed pathway for Src activation with FAK?Del33 remains to be elucidated. The present study used a retroviral expression system to examine changes in PTP? phosphorylation affected by the FAK?Del33 protein in breast cancer cells. Small interfering (si)RNA targeting PTP? interfered with the phosphorylation of Src. Wound?healing and migration assays were performed to identify cell morphology and quantitative analysis was performed by examining band color depth in western blot analysis. Significant differences were observed in the phosphorylation level of PTP? at Tyr789 between the FAK?Del33 and the wild?type breast cancer cells, suggesting that FAK regulated the phosphorylation level of PTP? at Tyr789 in breast cancer mutant FAK?Del33 cells. The gene expression profile with FAK siRNA did not alter the levels of phosphorylation in other mutants, including autophosphorylation disability (Y397F), ATP kinase dominant negative (K454R) and protein 4.1, ezrin, radixin, moesin domain attenuate (?375). FAK RNAi inhibited the activity of the FAK?Del33 at the Src site and rescued the elevated cell migration and invasion. The present study demonstrated for the first time, to the best of our knowledge, an increase in the phosphorylation level of PTP??Tyr789 by its upstream activator, FAK?Del33, leading to Src activation in certain breast cancer cells, which has significant implications for metastatic potential. PMID:25625869

  7. Binding of CD157 Protein to Fibronectin Regulates Cell Adhesion and Spreading*

    PubMed Central

    Morone, Simona; Augeri, Stefania; Cuccioloni, Massimiliano; Mozzicafreddo, Matteo; Angeletti, Mauro; Lo Buono, Nicola; Giacomino, Alice; Ortolan, Erika; Funaro, Ada

    2014-01-01

    CD157/BST-1 behaves both as an ectoenzyme and signaling receptor and is an important regulator of leukocyte trafficking and ovarian cancer progression. However, the molecular interactions underpinning the role of CD157 in these processes remain obscure. The biological functions of CD157 and its partnership with members of the integrin family prompted us to assume the existence of a direct interaction between CD157 and an unknown component of the extracellular matrix. Using solid-phase binding assays and surface plasmon resonance analysis, we demonstrated that CD157 binds fibronectin with high affinity within its heparin-binding domains 1 and 2. Furthermore, we found that CD157 binds to other extracellular matrix proteins containing heparin-binding domains. Finally, we proved that the CD157-fibronectin interaction occurs with living cells, where it elicits CD157-mediated cell responses. Indeed, knockdown of CD157 in Met-5A mesothelial cells changed their morphology and cytoskeleton organization and attenuated the activation of intracellular signaling pathways triggered by fibronectin. This led to impaired cell spreading and adhesion to selected extracellular matrix proteins. Collectively, these findings indicate a central role of CD157 in cell-extracellular matrix interactions and make CD157 an attractive therapeutic target in inflammation and cancer. PMID:24753259

  8. Interfacial tension of complex coacervated mussel adhesive protein according to the Hofmeister series.

    PubMed

    Lim, Seonghye; Moon, Dustin; Kim, Hyo Jeong; Seo, Jeong Hyun; Kang, In Seok; Cha, Hyung Joon

    2014-02-01

    Complex coacervation is a liquid-liquid phase separation in a colloidal system of two oppositely charged polyelectrolytes or colloids. The interfacial tension of the coacervate phase is the key parameter for micelle formation and interactions with the encapsulating material. However, the relationship between interfacial tensions and various salt solutions is poorly understood in complex coacervation. In the present work, the complex coacervate dynamics of recombinant mussel adhesive protein (MAP) with hyaluronic acid (HA) were determined in the presence of Hofmeister series salt ions. Using measurements of absorbance, hydrodynamic diameter, capillary force, and receding contact angle in the bulk phase, the interfacial tensions of complex coacervated MAP/HA were determined to be 0.236, 0.256, and 0.287 mN/m in 250 mM NaHCOO, NaCl, and NaNO3 solutions, respectively. The sequences of interfacial tensions and contact angles of the complex coacervates in the presence of three sodium salts with different anions were found to follow the Hofmeister ordering. The tendency of interfacial tension between the coacervate and dilute phases in the presence of different types of Hofmeister salt ions could provide a better understanding of Hofmeister effects on complex coacervated materials based on the protein-polysaccharide system. This information can also be utilized for microencapsulation and adsorption by controlling intramolecular interactions. In addition, the injection molding dynamics of mussel byssus formation was potentially explained based on the measured interfacial tension of coacervated MAP. PMID:24490867

  9. The adhesive protein invasin of Yersinia pseudotuberculosis induces neutrophil extracellular traps via ?1 integrins.

    PubMed

    Gillenius, Erik; Urban, Constantin F

    2015-05-01

    Yersinia pseudotuberculosis adhesive protein invasin is crucial for the bacteria to cross the intestine epithelium by binding to ?1 integrins on M-cells and gaining access to the underlying tissues. After the crossing invasin can bind to ?1 integrins on other cell surfaces, however effector proteins delivered by the type III secretion system Y. pseudotuberculosis efficiently inhibit potential immune responses induced by this interaction. Here, we use mutant Y. pseudotuberculosis strains lacking the type III secretion system and additionally invasin-expressing Escherichia coli to analyze neutrophil responses towards invasin. Our data reveals that invasin induces production of reactive oxygen species and release of chromatin into the extracellular milieu, which we confirmed to be neutrophil extracellular traps by immunofluorescence microscopy. This was mediated through ?1 integrins and was dependent on both the production of reactive oxygen species and signaling through phosphoinositide 3-kinase. We therefore have gained insight into a potential role of integrins in inflammation and infection clearance that has not previously been described, suggesting that targeting of ?1 integrins could be utilized as an adjunctive therapy against yersiniosis. PMID:25576025

  10. The expression of an adhesion-related protein by clam hemocytes.

    PubMed

    White, M K; Miosky, D; Flessas, D A; Reinisch, C L

    1993-05-01

    Molluscs have circulating cells in the hemolymph which are both adherent and phagocytic. Mya arenaria, the soft-shell clam, is particularly interesting because it develops a leukemia detected first in the hemolymph and, as the disease progresses, in solid tissue. We have previously described a leukemia-specific protein (Miosky et al., 1989) identified by murine monoclonal antibodies generated to pure populations of leukemia cells. In the following work, a monoclonal antibody was generated to normal hemocytes of Mya. The antibody, designated 2A4, was evaluated by ELISA, immunocytochemistry, Western blotting, and flow cytometry. The 2A4 antigen was detected on 87% normal adherent cells. However, 2A4 was lost as leukemia cells proliferated. The mature leukemia cell, which is nonadherent, neither expresses 2A4 nor can 2A4 be detected in the leukemia cell lystate. Western blot analyses reveal that 2A4 reacts with a 130-kDa protein. Our data suggest that p130 may be involved in the regulation of cell adhesion. PMID:8360513

  11. Cytomegalovirus Destruction of Focal Adhesions Revealed in a High-Throughput Western Blot Analysis of Cellular Protein Expression† ?

    PubMed Central

    Stanton, R. J.; McSharry, B. P.; Rickards, C. R.; Wang, E. C. Y.; Tomasec, P.; Wilkinson, G. W. G.

    2007-01-01

    Human cytomegalovirus (HCMV) systematically manages the expression of cellular functions, rather than exerting the global shutoff of host cell protein synthesis commonly observed with other herpesviruses during the lytic cycle. While microarray technology has provided remarkable insights into viral control of the cellular transcriptome, HCMV is known to encode multiple mechanisms for posttranscriptional and posttranslation regulation of cellular gene expression. High-throughput Western blotting (BD Biosciences Powerblot technology) with 1,009 characterized antibodies was therefore used to analyze and compare the effects of infection with attenuated high-passage strain AD169 and virulent low-passage strain Toledo at 72 hpi across gels run in triplicate for each sample. Six hundred ninety-four proteins gave a positive signal in the screen, of which 68 from strain AD169 and 71 from strain Toledo were defined as being either positively or negatively regulated by infection with the highest level of confidence (BD parameters). In follow-up analyses, a subset of proteins was selected on the basis of the magnitude of the observed effect or their potential to contribute to defense against immune recognition. In analyses performed at 24, 72, and 144 hpi, connexin 43 was efficiently downregulated during HCMV infection, implying a breakdown of intercellular communication. Mitosis-associated protein Eg-5 was found to be differentially upregulated in the AD169 and Toledo strains of HCMV. Focal adhesions link the actin cytoskeleton to the extracellular matrix and have key roles in initiating signaling pathways and substrate adhesion and regulating cell migration. HCMV suppressed expression of the focal-adhesion-associated proteins Hic-5, paxillin, and ?-actinin. Focal adhesions were clearly disrupted in HCMV-infected fibroblasts, with their associated intracellular and extracellular proteins being dispersed. Powerblot shows potential for rapid screening of the cellular proteome during HCMV infection. PMID:17522202

  12. Human DCXR - another 'moonlighting protein' involved in sugar metabolism, carbonyl detoxification, cell adhesion and male fertility?

    PubMed

    Ebert, Bettina; Kisiela, Michael; Maser, Edmund

    2015-02-01

    Dicarbonyl/L-xylulose reductase (DCXR; SDR20C1), a member of the short-chain dehydrogenase/reductase (SDR) superfamily catalyzes the reduction of ?-dicarbonyl compounds and monosaccharides. Its role in the metabolism of L-xylulose has been known since 1970, when essential pentosuria was found to be associated with DCXR deficiency. Despite its early discovery, our knowledge about the role of human DCXR in normal physiology and pathophysiology is still incomplete. Sporadic studies have demonstrated aberrant expression in several cancers, but their physiological significance is unknown. In reproductive medicine, where DCXR is commonly referred to as 'sperm surface protein P34H', it serves as marker for epididymal sperm maturation and is essential for gamete interaction and successful fertilization. DCXR exhibits a multifunctional nature, both acting as a carbonyl reductase and also performing non-catalytic functions, possibly resulting from interactions with other proteins. Recent observations associate DCXR with a role in cell adhesion, pointing to a novel function involving tumour progression and possibly metastasis. This review summarizes the current knowledge about human DCXR and its orthologs from mouse and Caenorhabditis elegans (DHS-21) with an emphasis on its multifunctional characteristics. Due to its close structural relationship with DCXR, carbonyl reductase 2 (Cbr2), a tetrameric enzyme found in several non-primate species is also discussed. Similar to human DCXR, Cbr2 from golden hamster (P26h) and cow (P25b) is essential for sperm-zona pellucida interaction and fertilization. Because of the apparent similarity of these two proteins and the inconsistent use of alternative names previously, we provide an overview of the systematic classification of DCXR and Cbr2 and a phylogenetic analysis to illustrate their ancestry. PMID:24720935

  13. Synthesis and characterization of cell-adhesive silk-like proteins constructed from the sequences of Anaphe silk fibroin and fibronectin.

    PubMed

    Tanaka, Chikako; Asakura, Tetsuo

    2009-04-13

    New silk-like recombinant proteins, [(AAG)(6)ASTGRGDSPAAS](n) and [(AG)(9)ASTGRGDSPAAS](n), with high cell adhesive activities were designed and produced from E. coli. These are recombinant proteins with characteristic sequences from the silk fibroin of a wild silkworm, Anaphe , and the cell adhesive region, including the sequence RGD derived from fibronectin. They showed higher cell adhesion activity than the parent protein, Anaphe silk fibroin without the RGD sequence. In addition, the activities were very similar to that of collagen, which acted as a positive control. Thus, it is demonstrated that the primary structure of Anaphe silk fibroin, which is composed largely of alanine and glycine residues, can be used as a platform for the basic structures of silk-like cell adhesive proteins. The structural characterization of the silk-like recombinant proteins was performed with (13)C CP/MAS NMR. PMID:19236090

  14. Fetuin-A, a hepatocyte-specific protein that binds Plasmodium berghei thrombospondin-related adhesive protein: a potential role in infectivity.

    PubMed

    Jethwaney, Deepa; Lepore, Timothy; Hassan, Saria; Mello, Kerrianne; Rangarajan, Radha; Jahnen-Dechent, Willi; Wirth, Dyann; Sultan, Ali A

    2005-09-01

    Malaria infection is initiated when the insect vector injects Plasmodium sporozoites into a susceptible vertebrate host. Sporozoites rapidly leave the circulatory system to invade hepatocytes, where further development generates the parasite form that invades and multiplies within erythrocytes. Previous experiments have shown that the thrombospondin-related adhesive protein (TRAP) plays an important role in sporozoite infectivity for hepatocytes. TRAP, a typical type-1 transmembrane protein, has a long extracellular region, which contains two adhesive domains, an A-domain and a thrombospondin repeat. We have generated recombinant proteins of the TRAP adhesive domains. These TRAP fragments show direct interaction with hepatocytes and inhibit sporozoite invasion in vitro. When the recombinant TRAP A-domain was used for immunoprecipitation against hepatocyte membrane fractions, it bound to alpha2-Heremans-Schmid glycoprotein/fetuin-A, a hepatocyte-specific protein associated with the extracellular matrix. When the soluble sporozoite protein fraction was immunoprecipitated on a fetuin-A-adsorbed protein A column, TRAP bound this ligand. Importantly, anti-fetuin-A antibodies inhibited invasion of hepatocytes by sporozoites. Further, onset of malaria infection was delayed in fetuin-A-deficient mice compared to that in wild-type C57BL/6 mice when they were challenged with Plasmodium berghei sporozoites. These data demonstrate that the extracellular region of TRAP interacts with fetuin-A on hepatocyte membranes and that this interaction enhances the parasite's ability to invade hepatocytes. PMID:16113307

  15. Regulation of T-lymphocyte motility, adhesion and de-adhesion by a cell surface mechanism directed by low density lipoprotein receptor-related protein 1 and endogenous thrombospondin-1.

    PubMed

    Talme, Toomas; Bergdahl, Eva; Sundqvist, Karl-Gösta

    2014-06-01

    T lymphocytes are highly motile and constantly reposition themselves between a free-floating vascular state, transient adhesion and migration in tissues. The regulation behind this unique dynamic behaviour remains unclear. Here we show that T cells have a cell surface mechanism for integrated regulation of motility and adhesion and that integrin ligands and CXCL12/SDF-1 influence motility and adhesion through this mechanism. Targeting cell surface-expressed low-density lipoprotein receptor-related protein 1 (LRP1) with an antibody, or blocking transport of LRP1 to the cell surface, perturbed the cell surface distribution of endogenous thrombospondin-1 (TSP-1) while inhibiting motility and potentiating cytoplasmic spreading on intercellular adhesion molecule 1 (ICAM-1) and fibronectin. Integrin ligands and CXCL12 stimulated motility and enhanced cell surface expression of LRP1, intact TSP-1 and a 130,000 MW TSP-1 fragment while preventing formation of a de-adhesion-coupled 110 000 MW TSP-1 fragment. The appearance of the 130 000 MW TSP-1 fragment was inhibited by the antibody that targeted LRP1 expression, inhibited motility and enhanced spreading. The TSP-1 binding site in the LRP1-associated protein, calreticulin, stimulated adhesion to ICAM-1 through intact TSP-1 and CD47. Shear flow enhanced cell surface expression of intact TSP-1. Hence, chemokines and integrin ligands up-regulate a dominant motogenic pathway through LRP1 and TSP-1 cleavage and activate an associated adhesion pathway through the LRP1-calreticulin complex, intact TSP-1 and CD47. This regulation of T-cell motility and adhesion makes pro-adhesive stimuli favour motile responses, which may explain why T cells prioritize movement before permanent adhesion. PMID:24877199

  16. Modulation of endogenous Cysteine Protease Inhibitor (ICP) 1 expression in Entamoeba histolytica affects amoebic adhesion to Extracellular Matrix proteins.

    PubMed

    Lee, Young Ah; Saito-Nakano, Yumiko; Kim, Kyeong Ah; Min, Arim; Nozaki, Tomoyoshi; Shin, Myeong Heon

    2015-02-01

    Entamoeba histolytica is an enteric tissue-invading protozoan parasite that causes amoebic colitis and occasionally liver abscess in humans. During tissue invasion, amoebic adhesion to host components is an important event for host cell death leading to successful invasion and infection. Among amoebic virulence factors, Gal/GalNAc lectin is known to be major adhesion factor to host cells. In this study, we investigated the role of amoebic secreted CP (Cysteine Proteases) in amoebic adhesion to extracellular matrix (ECM) protein using CP inhibitor and E. histolytica strains in which the endogenous inhibitor of cysteine protease (ICP) 1 gene was overexpressed (ICP1(+)) or repressed by antisense small RNA-mediated gene silencing (ICP1(-)). We found that pretreatment of wild-type amoebae with CP inhibitor E64, or thiol-group modifiers such as diamide and N-Ethylmaleimide resulted in a significant decrease in adhesion to laminin and collagen ECM proteins. Furthermore, ICP1(+) strain, with a reduction of secreted CP activity, exhibited reduced ability by 40% to adhere to laminin. In contrast, ICP1(-) strain, with a 1.9-fold increase of secreted CP activity, showed a two-fold increase in amoebic adherence to laminin compared to the control strain. In addition, total amount of secreted CP5 was decreased in ICP1(+) amoeba. Conversely, total amount of secreted CP1 and mature-form CP5 were increased in ICP1(-) amoeba. We also found that ICP1 was secreted into extracellular milieu. These results suggest that secreted CP activity by E. histolytica may be an important factor affecting adhesion to host proteins, and regulation of CP secretion by ICP plays a major role in pathogenesis. This study provides insight into the CP-mediated tissue pathogenesis in amoeba-invaded lesions during human amoebiasis. PMID:25500214

  17. Mammalian Adenylyl Cyclase-associated Protein 1 (CAP1) Regulates Cofilin Function, the Actin Cytoskeleton, and Cell Adhesion*

    PubMed Central

    Zhang, Haitao; Ghai, Pooja; Wu, Huhehasi; Wang, Changhui; Field, Jeffrey; Zhou, Guo-Lei

    2013-01-01

    CAP (adenylyl cyclase-associated protein) was first identified in yeast as a protein that regulates both the actin cytoskeleton and the Ras/cAMP pathway. Although the role in Ras signaling does not extend beyond yeast, evidence supports that CAP regulates the actin cytoskeleton in all eukaryotes including mammals. In vitro actin polymerization assays show that both mammalian and yeast CAP homologues facilitate cofilin-driven actin filament turnover. We generated HeLa cells with stable CAP1 knockdown using RNA interference. Depletion of CAP1 led to larger cell size and remarkably developed lamellipodia as well as accumulation of filamentous actin (F-actin). Moreover, we found that CAP1 depletion also led to changes in cofilin phosphorylation and localization as well as activation of focal adhesion kinase (FAK) and enhanced cell spreading. CAP1 forms complexes with the adhesion molecules FAK and Talin, which likely underlie the cell adhesion phenotypes through inside-out activation of integrin signaling. CAP1-depleted HeLa cells also had substantially elevated cell motility as well as invasion through Matrigel. In summary, in addition to generating in vitro and in vivo evidence further establishing the role of mammalian CAP1 in actin dynamics, we identified a novel cellular function for CAP1 in regulating cell adhesion. PMID:23737525

  18. Staphylococcus aureus Fibronectin-Binding Protein A Mediates Cell-Cell Adhesion through Low-Affinity Homophilic Bonds

    PubMed Central

    Herman-Bausier, Philippe; El-Kirat-Chatel, Sofiane; Foster, Timothy J.

    2015-01-01

    ABSTRACT Staphylococcus aureus is an important opportunistic pathogen which is a leading cause of biofilm-associated infections on indwelling medical devices. The cell surface-located fibronectin-binding protein A (FnBPA) plays an important role in the accumulation phase of biofilm formation by methicillin-resistant S. aureus (MRSA), but the underlying molecular interactions are not yet established. Here, we use single-cell and single-molecule atomic force microscopy to unravel the mechanism by which FnBPA mediates intercellular adhesion. We show that FnBPA is responsible for specific cell-cell interactions that involve the FnBPA A domain and cause microscale cell aggregation. We demonstrate that the strength of FnBPA-mediated adhesion originates from multiple low-affinity homophilic interactions between FnBPA A domains on neighboring cells. Low-affinity binding by means of FnBPA may be important for biofilm dynamics. These results provide a molecular basis for the ability of FnBPA to promote cell accumulation during S. aureus biofilm formation. We speculate that homophilic interactions may represent a generic strategy among staphylococcal cell surface proteins for guiding intercellular adhesion. As biofilm formation by MRSA strains depends on proteins rather than polysaccharides, our approach offers exciting prospects for the design of drugs or vaccines to inhibit protein-dependent intercellular interactions in MRSA biofilms. PMID:26015495

  19. Development of a rapid immunochromatographic test using a recombinant thrombospondin-related adhesive protein of Babesia gibsoni.

    PubMed

    Goo, Youn-Kyoung; Lee, Naeun; Terkawi, Mohamad Alaa; Luo, Yuzi; Aboge, Gabriel Oluga; Nishikawa, Yoshifumi; Suzuki, Hiroshi; Kim, Suk; Xuan, Xuenan

    2012-12-21

    We developed an immunochromatographic test (ICT) with the full-length of thrombospondin-related adhesive protein of Babesia gibsoni expressed by the modified expression method. The developed ICT showed high sensitivity, specificity, and kappa value with a reference test (100%, 93.78%, and 0.8976, respectively), indicating that the ICT could be a new practical diagnostic test for B. gibsoni infection. PMID:22795671

  20. Adhesive Bond Stiffness of Staphylococcus aureus with and without Proteins That Bind to an Adsorbed Fibronectin Film

    PubMed Central

    Olsson, Adam L. J.; van der Mei, Henny C.; Busscher, Henk J.

    2012-01-01

    Staphylococcus aureus is known to cause biomaterial-associated infections of implants and devices once it has breached the skin and mucosal barriers. Adhesion is the initial step in the development of a biomaterial-associated infection, and strategies to prevent staphylococcal adhesion and thus biomaterial-associated infections require understanding of the adhesive bond. The aim of this study was to compare the adhesive bond stiffnesses of two S. aureus strains with and without fibronectin-binding proteins (FnBPs) adhering to a fibronectin-coated quartz crystal microbalance (QCM) sensor surface on the basis of a coupled- resonance model. Both fibronectin adsorption and staphylococcal adhesion were accompanied by negative frequency shifts, regardless of the absence or presence of FnBPs on the staphylococcal cell surfaces. This is the opposite of the positive frequency shifts often observed for other bacterial strains adhering to bare sensor surfaces. Most likely, adhering staphylococci sink into and deform the adsorbed protein layer, creating stiff binding with the sensor surface due to an increased bacterium-substratum contact area. S. aureus 8325-4 possesses FnBPs and yields less negative frequency shifts (?f) that are further away from the zero-crossing frequency than S. aureus DU5883. This suggests that FnBPs on S. aureus 8325-4 create a stiffer bond to the fibronectin coating than has been observed for S. aureus DU5883. Due to a limited window of observation, as defined by the available resonance frequencies in QCM, we could not determine exact stiffness values. PMID:22038608

  1. Pregnancy-associated plasma protein A up-regulated by progesterone promotes adhesion and proliferation of trophoblastic cells

    PubMed Central

    Wang, Jiao; Liu, Shuai; Qin, Hua-Min; Zhao, Yue; Wang, Xiao-Qi; Yan, Qiu

    2014-01-01

    Embryo implantation and development is a complex biological process for the establishment of the successful pregnancy. Progesterone is a critical factor in the regulation of embryo adhesion to uterine endometrium and proliferation. Although it has been reported that pregnancy-associated plasma protein A (PAPPA) is increased in pregnant women, the relationship between progesterone and PAPPA, and the effects of PAPPA on embryo adhesion and proliferation are still not clear. The present results showed that the serum level of progesterone and PAPPA was closely correlated by ELISA assay (p < 0.01). PAPPA was detected in the villi of early embryo by RT-PCR, Western blot, immunohistochemistry and immunofluorescent staining. Moreover, PAPPA was significantly up-regulated by progesterone in trophoblastic (JAR) cells by Real-time PCR and ELISA assay (p < 0.01); while the expression was decreased by the progesterone receptor inhibitor RU486. The down-regulation of PAPPA by siRNA transfection or up-regulation of PAPPA by progesterone treatment significantly decreased or increased the adhesion rate of trophoblastic cells to human uterine epithelial cell lines (RL95-2 and HEC-1A), respectively (p < 0.01), as well as the proliferation of trophoblastic cells. In conclusion, PAPPA is up-regulated by progesterone, which promotes the adhesion and proliferation potential of trophoblastic cells. PMID:24817938

  2. Developmental lead exposure disturbs expression of synaptic neural cell adhesion molecules in herring gull brains.

    PubMed

    Dey, P M; Burger, J; Gochfeld, M; Reuhl, K R

    2000-05-01

    Neurobehavioral testing of herring gull chicks (Larus argentatus) in both laboratory and field studies indicates that lead exposure during critical periods of development causes neurological deficits that may compromise survival in the wild. Accumulating evidence suggests that lead impairs neurodevelopment, in part, by altering the expression of cell adhesion molecules (CAMs) responsible for the proper formation and maintenance of neural structure and synaptic function. We examined the adhesion molecules NCAM, L1, and N-cadherin in gull brains to determine whether these CAMs are altered by lead exposure and might serve as markers of developmental neurotoxicity. One-day-old chicks were collected from nesting colonies and were laboratory housed. On post-hatching day (PHD) 2, chicks were given 100 mg/kg lead acetate or saline (intraperitoneally). Birds were killed on PHD 34, 44, or 55 (blood-lead levels averaged 27.4, 20.8, and 19.5 microg/dl, respectively). Brains were removed and stored at -70 degrees C until analysis. Expression of CAMs was determined in synaptosomal preparations by Western blotting and the activity of NCAM-associated sialyltransferase (ST) was determined in purified whole brain golgi apparatus. Elevation in synaptosomal polysialylated NCAM expression and a significant increase in golgi ST activity was observed in lead-treated animals at PHD 34. Reductions in synaptosomal N-cadherin were observed at PHD 34 and 44, while L1 expression appeared unaffected by lead at any time-point. By 55 days post-hatching, no differences in N-cadherin expression, polysialylated NCAM expression or NCAM-associated ST activity were seen in lead-treated animals as compared with age-matched control animals. Lead-induced disruption of CAM expression during early neurodevelopment may contribute to behavioral deficits observed in herring gulls in both the laboratory and the field, and may serve as a marker for heavy metal exposure during postnatal development. PMID:10814846

  3. The giant protein AHNAK involved in morphogenesis and laminin substrate adhesion of myelinating Schwann cells.

    PubMed

    Salim, Claudio; Boxberg, Ysander V; Alterio, Jeanine; Féréol, Sophie; Nothias, Fatiha

    2009-04-01

    Within the nervous system, expression of the intriguing giant protein AHNAK had been reported so far only for blood-brain barrier forming vascular endothelium. In a screen for genes upregulated after spinal cord injury, we recently identified ahnak as being highly expressed by non-neuronal cells invading the lesion, delimiting the interior surface of cystic cavities in front of barrier-forming astrocytes. Here, we show for the first time that AHNAK is constitutively expressed in peripheral nervous system, notably by myelinating Schwann cells (SCs), in which we investigated its function. During sciatic nerve development, AHNAK is redistributed from adaxonal toward abaxonal SC compartments in contact with basement membrane. AHNAK labeling on myelinated fibers from adult nerve delineates the so-called "Cajal bands," constituting the residual peripheral SC cytoplasm. Its distribution pattern is complementary to that of periaxin, known to be involved in the myelination process. In vitro, nonconfluent cultured primary SCs seeded on laminin express high levels of AHNAK concentrated in their processes, whereas at confluence, AHNAK is downregulated together with laminin receptor dystroglycan. AHNAK silencing by siRNA interference affects SC morphology and laminin-substrate attachment, as well as expression and distribution of dystroglycan. Thus, our results clearly show the implication of AHNAK in SC adhesion to laminin, probably via targeting of the dystroglycan-associated receptor complex. These findings are of high interest regarding the importance of SC-basal lamina interactions for myelination and myelin maintenance, and open up new perspectives for investigations of the molecular mechanisms underlying demyelinating neuropathies. PMID:18837049

  4. Diversifying selection on the thrombospondin-related adhesive protein (TRAP) gene of Plasmodium falciparum in Thailand.

    PubMed

    Ohashi, Jun; Suzuki, Yuji; Naka, Izumi; Hananantachai, Hathairad; Patarapotikul, Jintana

    2014-01-01

    Sporozoites of Plasmodium falciparum are transmitted to human hosts by Anopheles mosquitoes. Thrombospondin-related adhesive protein (TRAP) is expressed in sporozoites and plays a crucial role in sporozoite gliding and invasion of human hepatocytes. A previous study showed that the TRAP gene has been subjected to balancing selection in the Gambian P. falciparum population. To further study the molecular evolution of the TRAP gene in Plasmodium falciparum, we investigated TRAP polymorphisms in P. falciparum isolates from Suan Phueng District in Ratchaburi Province, Thailand. The analysis of the entire TRAP coding sequences in 32 isolates identified a total of 39 single nucleotide polymorphisms (SNPs), which comprised 37 nonsynonymous and two synonymous SNPs. McDonald-Kreitman test showed that the ratio of the number of nonsynonymous to synonymous polymorphic sites within P. falciparum was significantly higher than that of the number of nonsynonymous to synonymous fixed sites between P. falciparum and P. reichenowi. Furthermore, the rate of nonsynonymous substitution was significantly higher than that of synonymous substitution within Thai P. falciparum. These results indicate that the TRAP gene has been subject to diversifying selection in the Thai P. falciparum population as well as the Gambian P. falciparum population. Comparison of our P. falciparum isolates with those from another region of Thailand (Tak province, Thailand) revealed that TRAP was highly differentiated between geographically close regions. This rapid diversification seems to reflect strong recent positive selection on TRAP. Our results suggest that the TRAP molecule is a major target of the human immune response to pre-erythrocytic stages of P. falciparum. PMID:24587387

  5. The adhesion modulation protein, AmpA localizes to an endocytic compartment and influences substrate adhesion, actin polymerization and endocytosis in vegetative Dictyostelium cells

    PubMed Central

    2012-01-01

    Background AmpA is a secreted 24Kd protein that has pleiotropic effects on Dictyostelium development. Null mutants delay development at the mound stage with cells adhering too tightly to the substrate. Prestalk cells initially specify as prespore cells and are delayed in their migration to the mound apex. Extracellular AmpA can rescue these defects, but AmpA is also necessary in a cell autonomous manner for anterior like cells (ALCs) to migrate to the upper cup. The ALCs are only 10% of the developing cell population making it difficult to study the cell autonomous effect of AmpA on the migration of these cells. AmpA is also expressed in growing cells, but, while it contains a hydrophobic leader sequence that is cleaved, it is not secreted from growing cells. This makes growing cells an attractive system for studying the cell autonomous function of AmpA. Results In growing cells AmpA plays an environment dependent role in cell migration. Excess AmpA facilitates migration on soft, adhesive surfaces but hinders migration on less adhesive surfaces. AmpA also effects the level of actin polymerization. Knockout cells polymerize less actin while over expressing cells polymerize more actin than wild type. Overexpression of AmpA also causes an increase in endocytosis that is traced to repeated formation of multiple endocytic cups at the same site on the membrane. Immunofluorescence analysis shows that AmpA is found in the Golgi and colocalizes with calnexin and the slow endosomal recycling compartment marker, p25, in a perinuclear compartment. AmpA is found on the cell periphery and is endocytically recycled to the perinuclear compartment. Conclusion AmpA is processed through the secretory pathway and traffics to the cell periphery where it is endocytosed and localizes to what has been defined as a slow endosomal recycling compartment. AmpA plays a role in actin polymerization and cell substrate adhesion. Additionally AmpA influences cell migration in an environment dependent manner. Wild type cells show very little variation in migration rates under the different conditions examined here, but either loss or over expression of AmpA cause significant substrate and environment dependent changes in migration. PMID:23126556

  6. Identification, purification, and characterization of a zyxin-related protein that binds the focal adhesion and microfilament protein VASP (vasodilator-stimulated phosphoprotein).

    PubMed Central

    Reinhard, M; Jouvenal, K; Tripier, D; Walter, U

    1995-01-01

    VASP (vasodilator-stimulated phosphoprotein), an established substrate of cAMP- and cGMP-dependent protein kinases in vitro and in living cells, is associated with focal adhesions, microfilaments, and membrane regions of high dynamic activity. Here, the identification of an 83-kDa protein (p83) that specifically binds VASP in blot overlays of different cell homogenates is reported. With VASP overlays as a detection tool, p83 was purified from porcine platelets and used to generate monospecific polyclonal antibodies. VASP binding to purified p83 in solid-phase binding assays and the closely matching subcellular localization in double-label immunofluorescence analyses demonstrated that both proteins also directly interact as native proteins in vitro and possibly in living cells. The subcellular distribution, the biochemical properties, as well as microsequencing data revealed that porcine platelet p83 is related to chicken gizzard zyxin and most likely represents the mammalian equivalent of the chicken protein. The VASP-p83 interaction may contribute to the targeting of VASP to focal adhesions, microfilaments, and dynamic membrane regions. Together with our recent identification of VASP as a natural ligand of the profilin poly-(L-proline) binding site, our present results suggest that, by linking profilin to zyxin/p83, VASP may participate in spatially confined profilin-regulated F-actin formation. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 6 PMID:7644520

  7. SpyAD, a Moonlighting Protein of Group A Streptococcus Contributing to Bacterial Division and Host Cell Adhesion

    PubMed Central

    Gallotta, Marilena; Gancitano, Giovanni; Pietrocola, Giampiero; Mora, Marirosa; Pezzicoli, Alfredo; Tuscano, Giovanna; Chiarot, Emiliano; Nardi-Dei, Vincenzo; Taddei, Anna Rita; Rindi, Simonetta; Speziale, Pietro; Soriani, Marco; Bensi, Giuliano

    2014-01-01

    Group A streptococcus (GAS) is a human pathogen causing a wide repertoire of mild and severe diseases for which no vaccine is yet available. We recently reported the identification of three protein antigens that in combination conferred wide protection against GAS infection in mice. Here we focused our attention on the characterization of one of these three antigens, Spy0269, a highly conserved, surface-exposed, and immunogenic protein of unknown function. Deletion of the spy0269 gene in a GAS M1 isolate resulted in very long bacterial chains, which is indicative of an impaired capacity of the knockout mutant to properly divide. Confocal microscopy and immunoprecipitation experiments demonstrated that the protein was mainly localized at the cell septum and could interact in vitro with the cell division protein FtsZ, leading us to hypothesize that Spy0269 is a member of the GAS divisome machinery. Predicted structural domains and sequence homologies with known streptococcal adhesins suggested that this antigen could also play a role in mediating GAS interaction with host cells. This hypothesis was confirmed by showing that recombinant Spy0269 could bind to mammalian epithelial cells in vitro and that Lactococcus lactis expressing Spy0269 on its cell surface could adhere to mammalian cells in vitro and to mice nasal mucosa in vivo. On the basis of these data, we believe that Spy0269 is involved both in bacterial cell division and in adhesion to host cells and we propose to rename this multifunctional moonlighting protein as SpyAD (Streptococcus pyogenes Adhesion and Division protein). PMID:24778116

  8. SpyAD, a moonlighting protein of group A Streptococcus contributing to bacterial division and host cell adhesion.

    PubMed

    Gallotta, Marilena; Gancitano, Giovanni; Pietrocola, Giampiero; Mora, Marirosa; Pezzicoli, Alfredo; Tuscano, Giovanna; Chiarot, Emiliano; Nardi-Dei, Vincenzo; Taddei, Anna Rita; Rindi, Simonetta; Speziale, Pietro; Soriani, Marco; Grandi, Guido; Margarit, Immaculada; Bensi, Giuliano

    2014-07-01

    Group A streptococcus (GAS) is a human pathogen causing a wide repertoire of mild and severe diseases for which no vaccine is yet available. We recently reported the identification of three protein antigens that in combination conferred wide protection against GAS infection in mice. Here we focused our attention on the characterization of one of these three antigens, Spy0269, a highly conserved, surface-exposed, and immunogenic protein of unknown function. Deletion of the spy0269 gene in a GAS M1 isolate resulted in very long bacterial chains, which is indicative of an impaired capacity of the knockout mutant to properly divide. Confocal microscopy and immunoprecipitation experiments demonstrated that the protein was mainly localized at the cell septum and could interact in vitro with the cell division protein FtsZ, leading us to hypothesize that Spy0269 is a member of the GAS divisome machinery. Predicted structural domains and sequence homologies with known streptococcal adhesins suggested that this antigen could also play a role in mediating GAS interaction with host cells. This hypothesis was confirmed by showing that recombinant Spy0269 could bind to mammalian epithelial cells in vitro and that Lactococcus lactis expressing Spy0269 on its cell surface could adhere to mammalian cells in vitro and to mice nasal mucosa in vivo. On the basis of these data, we believe that Spy0269 is involved both in bacterial cell division and in adhesion to host cells and we propose to rename this multifunctional moonlighting protein as SpyAD (Streptococcus pyogenes Adhesion and Division protein). PMID:24778116

  9. Acceleration of adhesion of cancer cells and neutrophils to endothelial cells in the absence of de novo protein synthesis: possible implication for involvement of hydroxyl radicals.

    PubMed

    Suzuki, K; Eguchi, H; Koh, Y H; Park, Y S; Taniguchi, N

    1999-04-01

    The adhesion of colon cancer cells (colo201) and neutrophils to endothelial cells which had been briefly exposed to either hypoxanthine/xanthine oxidase, or hydrogen peroxide, or peroxynitrite was analyzed in the absence of de novo protein synthesis. Such treatments accelerated the adhesions of both colo201 cells and neutrophils to endothelial cells. These effects were blocked by SOD/catalase or EDTA. The results provided evidence that hydroxyl radicals affect the cell surface of endothelial cells and accelerate cell adhesion. PMID:10092535

  10. b1 Integrin and Proteoglycan-Mediated Stimulation of T Lymphoma Cell Adhesion and Mitogen-Activated Protein Kinase Signaling by Thrombospondin1 and Thrombospondin1 Peptides

    Microsoft Academic Search

    Katherine E. Wilson; Zhuqing Li; Murat Kara; Kevin L. Gardner; David D. Roberts

    Cell-cell and cell-matrix interactions play important regulatory roles in lymphocyte homeostasis. Thrombospondin-1 (TSP1) is a matricellular protein that differentially promotes the adhesion of resting and activated T cells. In this work, we show that adhesion of Jurkat T cells on substrates coated with TSP1 or TSP1-derived peptides is mediated by b1 integrins, CD47, and heparan sulfate proteoglycans. Interactions with TSP1

  11. Loss of Cadherin-Binding Proteins ?-Catenin and Plakoglobin in the Heart Leads to Gap Junction Remodeling and Arrhythmogenesis

    PubMed Central

    Swope, David; Cheng, Lan; Gao, Erhe; Li, Jifen

    2012-01-01

    Arrhythmic right ventricular cardiomyopathy (ARVC) is a hereditary heart muscle disease that causes sudden cardiac death (SCD) in young people. Almost half of ARVC patients have a mutation in genes encoding cell adhesion proteins of the desmosome, including plakoglobin (JUP). We previously reported that cardiac tissue-specific plakoglobin (PG) knockout (PG CKO) mice have no apparent conduction abnormality and survive longer than expected. Importantly, the PG homolog, ?-catenin (CTNNB1), showed increased association with the gap junction protein connexin43 (Cx43) in PG CKO hearts. To determine whether ?-catenin is required to maintain cardiac conduction in the absence of PG, we generated mice lacking both PG and ?-catenin specifically in the heart (i.e., double knockout [DKO]). The DKO mice exhibited cardiomyopathy, fibrous tissue replacement, and conduction abnormalities resulting in SCD. Loss of the cadherin linker proteins resulted in dissolution of the intercalated disc (ICD) structure. Moreover, Cx43-containing gap junction plaques were reduced at the ICD, consistent with the arrhythmogenicity of the DKO hearts. Finally, ambulatory electrocardiogram monitoring captured the abrupt onset of spontaneous lethal ventricular arrhythmia in the DKO mice. In conclusion, these studies demonstrate that the N-cadherin-binding partners, PG and ?-catenin, are indispensable for maintaining mechanoelectrical coupling in the heart. PMID:22252313

  12. The Arcanobacterium pyogenes Collagen-Binding Protein, CbpA, Promotes Adhesion to Host Cells

    Microsoft Academic Search

    Paula A. Esmay; Stephen J. Billington; Malen A. Link; J. Glenn Songer; B. Helen Jost

    2003-01-01

    Arcanobacterium pyogenes is an opportunistic pathogen associated with suppurative diseases in economically important food animals such as cattle, pigs, and turkeys. A. pyogenes adheres to host epithelial cells, and adhesion is promoted by the action of neuraminidase, which is expressed by this organism. However, a neuraminidase-deficient mutant of A. pyogenes only had a reduced ability to adhere to host epithelial

  13. Protein Kinase C Activation Upregulates Intercellular Adhesion of ?-Catenin–negative Human Colon Cancer Cell Variants via Induction of Desmosomes

    PubMed Central

    Hengel, Jolanda van; Gohon, Lionel; Bruyneel, Erik; Vermeulen, Stefan; Cornelissen, Maria; Mareel, Marc; Roy, Frans van

    1997-01-01

    The ?-catenin molecule links E-cadherin/ ?-catenin or E-cadherin/plakoglobin complexes to the actin cytoskeleton. We studied several invasive human colon carcinoma cell lines lacking ?-catenin. They showed a solitary and rounded morphotype that correlated with increased invasiveness. These round cell variants acquired a more normal epithelial phenotype upon transfection with an ?-catenin expression plasmid, but also upon treatment with the protein kinase C (PKC) activator 12-O-tetradecanoyl-phorbol-13-acetate (TPA). Video registrations showed that the cells started to establish elaborated intercellular junctions within 30 min after addition of TPA. Interestingly, this normalizing TPA effect was not associated with ?-catenin induction. Classical and confocal immunofluorescence showed only minor TPA-induced changes in E-cadherin staining. In contrast, desmosomal and tight junctional proteins were dramatically rearranged, with a conversion from cytoplasmic clusters to obvious concentration at cell–cell contacts and exposition at the exterior cell surface. Electron microscopical observations revealed the TPA-induced appearance of typical desmosomal plaques. TPA-restored cell–cell adhesion was E-cadherin dependent as demonstrated by a blocking antibody in a cell aggregation assay. Addition of an antibody against the extracellular part of desmoglein-2 blocked the TPA effect, too. Remarkably, the combination of anti–E-cadherin and anti-desmoglein antibodies synergistically inhibited the TPA effect. Our studies show that it is possible to bypass the need for normal ?-catenin expression to establish tight intercellular adhesion by epithelial cells. Apparently, the underlying mechanism comprises upregulation of desmosomes and tight junctions by activation of the PKC signaling pathway, whereas E-cadherin remains essential for basic cell–cell adhesion, even in the absence of ?-catenin. PMID:9166410

  14. An immediate-early protein of white spot syndrome virus modulates the phosphorylation of focal adhesion kinase of shrimp.

    PubMed

    Lu, Huasong; Ruan, Lingwei; Xu, Xun

    2011-10-25

    WSSV interacts with integrin during infection of shrimps and modulate the focal adhesion kinase which is known as a regulator of several downstream signaling pathways. Viral protein kinases are thought to be important for virus infection by regulating the host signaling pathways. WSV083 is an immediate-early gene of white spot syndrome virus that contains a Ser/Thr protein kinase domain. So, does WSSV modulate FAK phosphorylation via the WSV083 molecule? In this study, co-transfection of WSV083 and MjFAK genes proceeded in insect cells revealed that the MjFAK phosphorylation and cell adhesion activity could be inhibited by the expression of WSV083. Kinase domain mutants of WSV083 lost its ability of inhibiting FAK phosphorylation. Moreover, silencing of FAK gene through RNAi accelerated the shrimp death rate upon WSSV challenge. These results demonstrate for the first time that modulation of FAK phosphorylation by WSV083 plays a critical role in the pathogenesis of WSSV infection. PMID:21908012

  15. Block Copolymer Arrangement and Composition Effects on Protein Conformation Using AFM-Based Antigen-Antibody Adhesion

    PubMed Central

    Palacio, Manuel L. B.; Schricker, Scott R.; Bhushan, Bharat

    2013-01-01

    The conformational changes of fibronectin deposited on various block copolymers where one block is composed of poly(methyl methacrylate) (PMMA) and the other block is either poly(acrylic acid) (PAA) or poly(2-hydroxyethyl methacrylate) (PHEMA) were investigated using a functionalized atomic force microscope (AFM) tip. The tip was modified with an antibody sensitive to the exposure of the arginine-glycine-aspartic acid (RGD) groups in fibronectin. By studying the adhesive interactions between the antibody and the proteins adsorbed on the block copolymer surface and phase imaging, it was found that the triblock copolymers PAA-b-PMMA-b-PAA and PMMA-b-PHEMA-b-PMMA, which both have large domain sizes, are conducive to the exposure of the fibronectin RGD groups on the surface. Based on these results, it is concluded that the surface chemistry as well as the nanomorphology dictated by the block copolymer arrangement could both tune protein conformation and orientation and optimize cell adhesion to the biomaterial surface. PMID:22278846

  16. Discovery of a novel and conserved Plasmodium falciparum exported protein that is important for adhesion of PfEMP1 at the surface of infected erythrocytes.

    PubMed

    Nacer, Adéla; Claes, Aurélie; Roberts, Amy; Scheidig-Benatar, Christine; Sakamoto, Hiroshi; Ghorbal, Mehdi; Lopez-Rubio, Jose-Juan; Mattei, Denise

    2015-08-01

    Plasmodium falciparum virulence is linked to its ability to sequester in post-capillary venules in the human host. Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) is the main variant surface antigen implicated in this process. Complete loss of parasite adhesion is linked to a large subtelomeric deletion on chromosome 9 in a number of laboratory strains such as D10 and T9-96. Similar to the cytoadherent reference line FCR3, D10 strain expresses PfEMP1 on the surface of parasitized erythrocytes, however without any detectable cytoadhesion. To investigate which of the deleted subtelomeric genes may be implicated in parasite adhesion, we selected 12 genes for D10 complementation studies that are predicted to code for proteins exported to the red blood cell. We identified a novel single copy gene (PF3D7_0936500) restricted to P.?falciparum that restores adhesion to CD36, termed here virulence-associated protein 1 (Pfvap1). Protein knockdown and gene knockout experiments confirmed a role of PfVAP1 in the adhesion process in FCR3 parasites. PfVAP1 is co-exported with PfEMP1 into the host cell via vesicle-like structures called Maurer's clefts. This study identifies a novel highly conserved parasite molecule that contributes to parasite virulence possibly by assisting PfEMP1 to establish functional adhesion at the host cell surface. PMID:25703704

  17. Grafted poly-(ethylene glycol) on lipid surfaces inhibits protein adsorption and cell adhesion

    Microsoft Academic Search

    Hong Du; Parthapratim Chandaroy; Sek Wen Hui

    1997-01-01

    Monolayers of dipalmitoyl-phosphatidylethanolamine (DPPE) mixing with various mole percentages of distearoyl-phosphatidylethanolamine (DSPE)-conjugated poly-(ethylene glycol) (PEG m.w. 750–5000) were deposited on DPPE-coated glass surfaces by the Langmuir-Blodgett method. Increasing percentages of grafted PEG in these supported lipid surfaces increasingly inhibit the adsorption of bovine serum albumin (BSA), laminin, and fibronectin. Increasing percentages of grafted PEG also inhibit the adhesion of erythrocytes,

  18. An adhesion protein of Salmonella enterica serovar Typhi is required for pathogenesis and potential target for vaccine development

    PubMed Central

    Ghosh, Shubhamoy; Chakraborty, Krishnendu; Nagaraja, Theeya; Basak, Surajit; Koley, Hemanta; Dutta, Shanta; Mitra, Utpala; Das, Santasabuj

    2011-01-01

    More than half of all Salmonella enterica serovar Typhi genes still remain unannotated. Although pathogenesis of S. Typhi is incompletely understood, treatment of typhoid fever is complicated by the emergence of drug resistance. Effectiveness of the currently available vaccines is also limited. In search of novel virulence proteins, we have identified several putative adhesins of S. Typhi through computational approaches. Our experiment shows that a 27-kDa outer membrane protein (T2544) plays a major role in bacterial adhesion to the host through high-affinity binding to laminin. Its role in bacterial pathogenesis is underscored by reduced systemic invasion and a 10-fold higher LD50 of the mutant bacteria in mice. T2544 is strongly immunogenic as revealed by the detection of sustained high titers of serum IgG and intestinal secretory IgA in the immunized mice. In vitro, T2544 antiserum enhanced uptake and clearance of Salmonella by macrophages and augmented complement-mediated lysis, indicating a contribution of T2544-specific antibodies to the killing process. This correlates well with the observed protection of mice immunized with recombinant T2544 or passively immunized with T2544 antiserum against subsequent bacterial challenge, suggesting that T2544-specific antibodies are involved in protection. The present study describes an adhesion protein of S. Typhi that contributes to bacterial pathogenesis. Protective antibodies in mice, rapid seroconversion of naturally infected individuals with increasing titers of anti-T2544 IgG from acute to convalescent sera suggesting antibody response in humans, and wide distribution and conservation of the cell-surface adhesin in the clinical isolates of different Salmonella serovars make T2544 a potential vaccine candidate. PMID:21300870

  19. ERK1/2 activation in heart is controlled by melusin, focal adhesion kinase and the scaffold protein IQGAP1.

    PubMed

    Sbroggiò, Mauro; Bertero, Alessandro; Velasco, Silvia; Fusella, Federica; De Blasio, Emanuele; Bahou, Wadie F; Silengo, Lorenzo; Turco, Emilia; Brancaccio, Mara; Tarone, Guido

    2011-10-15

    Extracellular signal-regulated kinase 1/2 (ERK1/2) signalling is a key pathway in cardiomyocyte hypertrophy and survival in response to many different stress stimuli. We have previously characterized melusin as a muscle-specific chaperone protein capable of ERK1/2 signalling activation in the heart. Here, we show that in the heart, melusin forms a supramolecular complex with the proto-oncogene c-Raf, MEK1/2 (also known as MAPKK1/2) and ERK1/2 and that melusin-bound mitogen-activated protein kinases (MAPKs) are activated by pressure overload. Moreover, we demonstrate that both focal adhesion kinase (FAK) and IQ motif-containing GTPase activating protein 1 (IQGAP1), a scaffold protein for the ERK1/2 signalling cascade, are part of the melusin complex and are required for ERK1/2 activation in response to pressure overload. Finally, analysis of isolated neonatal cardiomyocytes indicates that both FAK and IQGAP1 regulate melusin-dependent cardiomyocyte hypertrophy and survival through ERK1/2 activation. PMID:22010199

  20. Tyrosine Y189 in the substrate domain of the adhesion docking protein NEDD9 is conserved with p130Cas Y253 and regulates NEDD9-mediated migration and focal adhesion dynamics.

    PubMed

    Baquiran, Jaime B; Bradbury, Peta; O'Neill, Geraldine M

    2013-01-01

    The focal adhesion docking protein NEDD9/HEF1/Cas-L regulates cell migration and cancer invasion. NEDD9 is a member of the Cas family of proteins that share conserved overall protein-protein interaction domain structure, including a substrate domain that is characterized by extensive tyrosine (Y) phosphorylation. Previous studies have suggested that phosphorylation of Y253 in the substrate domain of the Cas family protein p130Cas is specifically required for p130Cas function in cell migration. While it is clear that tyrosine phosphorylation of the NEDD9 substrate domain is similarly required for the regulation of cell motility, whether individual NEDD9 tyrosine residues have discrete function in regulating motility has not previously been reported. In the present study we have used a global sequence alignment of Cas family proteins to identify a putative NEDD9 equivalent of p130Cas Y253. We find that NEDD9 Y189 aligns with p130Cas Y253 and that it is conserved among NEDD9 vertebrate orthologues. Expression of NEDD9 in which Y189 is mutated to phenylalanine results in increased rates of cell migration and is correlated with increased disassembly of GFP.NEDD9 focal adhesions. Conversely, mutation to Y189D significantly inhibits cell migration. Our previous data has suggested that NEDD9 stabilizes focal adhesions and the present data therefore suggests that phosphorylation of Y189 NEDD9 is required for this function. These findings indicate that the individual tyrosine residues of the NEDD9 substrate domain may serve discrete functional roles. Given the important role of this protein in promoting cancer invasion, greater understanding of the function of the individual tyrosine residues is important for the future design of approaches to target NEDD9 to arrest cancer cell invasion. PMID:23874939

  1. Why are enteric ganglia so small? Role of differential adhesion of enteric neurons and enteric neural crest cells.

    PubMed

    Rollo, Benjamin N; Zhang, Dongcheng; Simkin, Johanna E; Menheniott, Trevelyan R; Newgreen, Donald F

    2015-01-01

    The avian enteric nervous system (ENS) consists of a vast number of unusually small ganglia compared to other peripheral ganglia. Each ENS ganglion at mid-gestation has a core of neurons and a shell of mesenchymal precursor/glia-like enteric neural crest (ENC) cells. To study ENS cell ganglionation we isolated midgut ENS cells by HNK-1 fluorescence-activated cell sorting (FACS) from E5 and E8 quail embryos, and from E9 chick embryos. We performed cell-cell aggregation assays which revealed a developmentally regulated functional increase in ENS cell adhesive function, requiring both Ca (2+) -dependent and independent adhesion. This was consistent with N-cadherin and NCAM labelling. Neurons sorted to the core of aggregates, surrounded by outer ENC cells, showing that neurons had higher adhesion than ENC cells. The outer surface of aggregates became relatively non-adhesive, correlating with low levels of NCAM and N-cadherin on this surface of the outer non-neuronal ENC cells. Aggregation assays showed that ENS cells FACS selected for NCAM-high and enriched for enteric neurons formed larger and more coherent aggregates than unsorted ENS cells. In contrast, ENS cells of the NCAM-low FACS fraction formed small, disorganised aggregates.  This suggests a novel mechanism for control of ENS ganglion morphogenesis where i) differential adhesion of ENS neurons and ENC cells controls the core/shell ganglionic structure and ii) the ratio of neurons to ENC cells dictates the equilibrium ganglion size by generation of an outer non-adhesive surface. PMID:26064478

  2. Why are enteric ganglia so small? Role of differential adhesion of enteric neurons and enteric neural crest cells.

    PubMed Central

    Rollo, Benjamin N.; Zhang, Dongcheng; Simkin, Johanna E.; Menheniott, Trevelyan R.; Newgreen, Donald F.

    2015-01-01

    The avian enteric nervous system (ENS) consists of a vast number of unusually small ganglia compared to other peripheral ganglia. Each ENS ganglion at mid-gestation has a core of neurons and a shell of mesenchymal precursor/glia-like enteric neural crest (ENC) cells. To study ENS cell ganglionation we isolated midgut ENS cells by HNK-1 fluorescence-activated cell sorting (FACS) from E5 and E8 quail embryos, and from E9 chick embryos. We performed cell-cell aggregation assays which revealed a developmentally regulated functional increase in ENS cell adhesive function, requiring both Ca 2+ -dependent and independent adhesion. This was consistent with N-cadherin and NCAM labelling. Neurons sorted to the core of aggregates, surrounded by outer ENC cells, showing that neurons had higher adhesion than ENC cells. The outer surface of aggregates became relatively non-adhesive, correlating with low levels of NCAM and N-cadherin on this surface of the outer non-neuronal ENC cells. Aggregation assays showed that ENS cells FACS selected for NCAM-high and enriched for enteric neurons formed larger and more coherent aggregates than unsorted ENS cells. In contrast, ENS cells of the NCAM-low FACS fraction formed small, disorganised aggregates.  This suggests a novel mechanism for control of ENS ganglion morphogenesis where i) differential adhesion of ENS neurons and ENC cells controls the core/shell ganglionic structure and ii) the ratio of neurons to ENC cells dictates the equilibrium ganglion size by generation of an outer non-adhesive surface.

  3. Environmental toxicants perturb human Sertoli cell adhesive function via changes in F-actin organization mediated by actin regulatory proteins

    PubMed Central

    Xiao, Xiang; Mruk, Dolores D.; Tang, Elizabeth I.; Wong, Chris K.C.; Lee, Will M.; John, Constance M.; Turek, Paul J.; Silvestrini, Bruno; Cheng, C. Yan

    2014-01-01

    STUDY QUESTION Can human Sertoli cells cultured in vitro and that have formed an epithelium be used as a model to monitor toxicant-induced junction disruption and to better understand the mechanism(s) by which toxicants disrupt cell adhesion at the Sertoli cell blood–testis barrier (BTB)? SUMMARY ANSWER Our findings illustrate that human Sertoli cells cultured in vitro serve as a reliable system to monitor the impact of environmental toxicants on the BTB function. WHAT IS KNOWN ALREADY Suspicions of a declining trend in semen quality and a concomitant increase in exposures to environmental toxicants over the past decades reveal the need of an in vitro system that efficiently and reliably monitors the impact of toxicants on male reproductive function. Furthermore, studies in rodents have confirmed that environmental toxicants impede Sertoli cell BTB function in vitro and in vivo. STUDY DESIGN, SIZE AND DURATION We examined the effects of two environmental toxicants: cadmium chloride (0.5–20 µM) and bisphenol A (0.4–200 µM) on human Sertoli cell function. Cultured Sertoli cells from three men were used in this study, which spanned an 18-month period. PARTICIPANTS/MATERIALS, SETTING, METHODS Human Sertoli cells from three subjects were cultured in F12/DMEM containing 5% fetal bovine serum. Changes in protein expression were monitored by immunoblotting using specific antibodies. Immunofluorescence analyses were used to assess changes in the distribution of adhesion proteins, F-actin and actin regulatory proteins following exposure to two toxicants: cadmium chloride and bisphenol A (BPA). MAIN RESULTS AND THE ROLE OF CHANCE Human Sertoli cells were sensitive to cadmium and BPA toxicity. Changes in the localization of cell adhesion proteins were mediated by an alteration of the actin-based cytoskeleton. This alteration of F-actin network in Sertoli cells as manifested by truncation and depolymerization of actin microfilaments at the Sertoli cell BTB was caused by mislocalization of actin filament barbed end capping and bundling protein Eps8, and branched actin polymerization protein Arp3. Besides impeding actin dynamics, endocytic vesicle-mediated trafficking and the proper localization of actin regulatory proteins c-Src and annexin II in Sertoli cells were also affected. Results of statistical analysis demonstrate that these findings were not obtained by chance. LIMITATIONS, REASONS FOR CAUTION (i) This study was done in vitro and might not extrapolate to the in vivo state, (ii) conclusions are based on the use of Sertoli cell samples from three men and (iii) it is uncertain if the concentrations of toxicants used in the experiments are reached in vivo. WIDER IMPLICATIONS OF THE FINDINGS Human Sertoli cells cultured in vitro provide a robust model to monitor environmental toxicant-mediated disruption of Sertoli cell BTB function and to study the mechanism(s) of toxicant-induced testicular dysfunction. PMID:24532171

  4. Dynamic and Static Interactions between p120 Catenin and E-Cadherin Regulate the Stability of Cell-Cell Adhesion

    SciTech Connect

    Ishiyama, Noboru; Lee, Seung-Hye; Liu, Shuang; Li, Guang-Yao; Smith, Matthew J.; Reichardt, Louis F.; Ikura, Mitsuhiko (OCI); (UCSF)

    2010-04-26

    The association of p120 catenin (p120) with the juxtamembrane domain (JMD) of the cadherin cytoplasmic tail is critical for the surface stability of cadherin-catenin cell-cell adhesion complexes. Here, we present the crystal structure of p120 isoform 4A in complex with the JMD core region (JMD{sub core}) of E-cadherin. The p120 armadillo repeat domain contains modular binding pockets that are complementary to electrostatic and hydrophobic properties of the JMD{sub core}. Single-residue mutations within the JMD{sub core}-binding site of p120 abolished its interaction with E- and N-cadherins in vitro and in cultured cells. These mutations of p120 enabled us to clearly differentiate between N-cadherin-dependent and -independent steps of neuronal dendritic spine morphogenesis crucial for synapse development. NMR studies revealed that p120 regulates the stability of cadherin-mediated cell-cell adhesion by associating with the majority of the JMD, including residues implicated in clathrin-mediated endocytosis and Hakai-dependent ubiquitination of E-cadherin, through its discrete dynamic and static binding sites.

  5. Promotion of osteoblast proliferation on complex coacervation-based hyaluronic acid – recombinant mussel adhesive protein coatings on titanium

    PubMed Central

    Hwang, Dong Soo; Waite, J. Herbert; Tirrell, Matthew

    2010-01-01

    Many biological polyelectrolytes are capable of undergoing a fluid–fluid phase separation known as complex coacervation. Coacervates were prepared using hyaluronic acid (HA) and a recombinant fusion protein consisting of mussel adhesive motifs and the RGD peptide (fp-151-RGD). The low interfacial energy of the coacervate was exploited to coat titanium (Ti), a metal widely used in implant materials. The coacervate effectively distributed both HA and fp-151-RGD over the Ti surfaces and enhanced osteoblast proliferation. Approximately half of total fp-151-RGD and HA in the solution transferred to the titanium surface within 2 h. Titanium coated with coacervates having high residual negative surface charge showed the highest cell proliferation of preosteoblast cells (MC-3T3) compared to the treatments tested. Indeed, MC-3T3 cells on complex coacervate coated titanium foils exhibited over 5 times greater cell proliferation than bare, HA coated or fp-151-RGD coated titanium. PMID:19892396

  6. INFLAMMATORY CYTOKINES INDUCE INTERCELLULAR ADHESION MOLECULE1 (ICAM–1) mRNA SYNTHESIS AND PROTEIN SECRETION BY HUMAN RETINAL PIGMENT EPITHELIAL CELL CULTURES

    Microsoft Academic Search

    Chandrasekharam N. Nagineni; R. Krishnan Kutty; Barbara Detrick; John J. Hooks

    1996-01-01

    Retinal inflammatory diseases in man are associated with an upregulation in the expression of intercellular adhesion molecule-1 (ICAM–1) in cells within the retina and with an increase in soluble ICAM–1 within the vitreous. These studies suggest that this protein may contribute to immunopathological processes within the eye. The effects of inflammatory mediators on the regulation of the expression and secretion

  7. The Adhesion of Plasmodium falciparum-Infected Erythrocytes to Chondroitin Sulfate A Is Mediated by P. falciparum Erythrocyte Membrane Protein 1

    Microsoft Academic Search

    John C. Reeder; Alan F. Cowman; Kathleen M. Davern; James G. Beeson; Jennifer K. Thompson; Stephen J. Rogerson; Graham V. Brown

    1999-01-01

    Chondroitin sulfate A (CSA) is an important receptor for the sequestration of Plasmodium falciparum in the placenta, but the parasite ligand involved in adhesion has not previously been identified. Here we report the identification of a var gene transcribed in association with binding to CSA and present evidence that the P. falciparum erythrocyte membrane protein 1 product of the gene

  8. Role of Streptococcus gordonii Amylase-Binding Protein A in Adhesion to Hydroxyapatite, Starch Metabolism, and Biofilm Formation

    PubMed Central

    Rogers, Jeffrey D.; Palmer, Robert J.; Kolenbrander, Paul E.; Scannapieco, Frank A.

    2001-01-01

    Interactions between bacteria and salivary components are thought to be important in the establishment and ecology of the oral microflora. ?-Amylase, the predominant salivary enzyme in humans, binds to Streptococcus gordonii, a primary colonizer of the tooth. Previous studies have implicated this interaction in adhesion of the bacteria to salivary pellicles, catabolism of dietary starches, and biofilm formation. Amylase binding is mediated at least in part by the amylase-binding protein A (AbpA). To study the function of this protein, an erythromycin resistance determinant [erm(AM)] was inserted within the abpA gene of S. gordonii strains Challis and FAS4 by allelic exchange, resulting in abpA mutant strains Challis-E1 and FAS4-E1. Comparison of the wild-type and mutant strains did not reveal any significant differences in colony morphology, biochemical metabolic profiles, growth in complex or defined media, surface hydrophobicity, or coaggregation properties. Scatchard analysis of adhesion isotherms demonstrated that the wild-type strains adhered better to human parotid-saliva- and amylase-coated hydroxyapatite than did the AbpA mutants. In contrast, the mutant strains bound to whole-saliva-coated hydroxyapatite to a greater extent than did the wild-type strains. While the wild-type strains preincubated with purified salivary amylase grew well in defined medium with potato starch as the sole carbohydrate source, the AbpA mutants did not grow under the same conditions even after preincubation with amylase. In addition, the wild-type strain produced large microcolonies in a flow cell biofilm model, while the abpA mutant strains grew much more poorly and produced relatively small microcolonies. Taken together, these results suggest that AbpA of S. gordonii functions as an adhesin to amylase-coated hydroxyapatite, in salivary-amylase-mediated catabolism of dietary starches and in human saliva-supported biofilm formation by S. gordonii. PMID:11598080

  9. Role of Streptococcus gordonii amylase-binding protein A in adhesion to hydroxyapatite, starch metabolism, and biofilm formation.

    PubMed

    Rogers, J D; Palmer, R J; Kolenbrander, P E; Scannapieco, F A

    2001-11-01

    Interactions between bacteria and salivary components are thought to be important in the establishment and ecology of the oral microflora. alpha-Amylase, the predominant salivary enzyme in humans, binds to Streptococcus gordonii, a primary colonizer of the tooth. Previous studies have implicated this interaction in adhesion of the bacteria to salivary pellicles, catabolism of dietary starches, and biofilm formation. Amylase binding is mediated at least in part by the amylase-binding protein A (AbpA). To study the function of this protein, an erythromycin resistance determinant [erm(AM)] was inserted within the abpA gene of S. gordonii strains Challis and FAS4 by allelic exchange, resulting in abpA mutant strains Challis-E1 and FAS4-E1. Comparison of the wild-type and mutant strains did not reveal any significant differences in colony morphology, biochemical metabolic profiles, growth in complex or defined media, surface hydrophobicity, or coaggregation properties. Scatchard analysis of adhesion isotherms demonstrated that the wild-type strains adhered better to human parotid-saliva- and amylase-coated hydroxyapatite than did the AbpA mutants. In contrast, the mutant strains bound to whole-saliva-coated hydroxyapatite to a greater extent than did the wild-type strains. While the wild-type strains preincubated with purified salivary amylase grew well in defined medium with potato starch as the sole carbohydrate source, the AbpA mutants did not grow under the same conditions even after preincubation with amylase. In addition, the wild-type strain produced large microcolonies in a flow cell biofilm model, while the abpA mutant strains grew much more poorly and produced relatively small microcolonies. Taken together, these results suggest that AbpA of S. gordonii functions as an adhesin to amylase-coated hydroxyapatite, in salivary-amylase-mediated catabolism of dietary starches and in human saliva-supported biofilm formation by S. gordonii. PMID:11598080

  10. Surface-tethered polymers to influence protein adsorption and microbial adhesion

    Microsoft Academic Search

    Willem Norde

    2007-01-01

    In various applications it is desired that biological cells or protein molecules are immobilized at surfaces. Examples are enzymes or cells in bioreactors and biosensors, immuno-proteins in solid-state diagnostics and proteinaceous farmacons in drug delivery systems. In order to retain biological activity, the structural integrity of the immobilized bio-compounds should be preserved. In other cases immobilization of cells and proteins

  11. Hydrogen-Rich Medium Attenuated Lipopolysaccharide-Induced Monocyte-Endothelial Cell Adhesion and Vascular Endothelial Permeability via Rho-Associated Coiled-Coil Protein Kinase.

    PubMed

    Xie, Keliang; Wang, Weina; Chen, Hongguang; Han, Huanzhi; Liu, Daquan; Wang, Guolin; Yu, Yonghao

    2015-07-01

    Sepsis is the leading cause of death in critically ill patients. In recent years, molecular hydrogen, as an effective free radical scavenger, has been shown a selective antioxidant and anti-inflammatory effect, and it is beneficial in the treatment of sepsis. Rho-associated coiled-coil protein kinase (ROCK) participates in junction between normal cells, and regulates vascular endothelial permeability. In this study, we used lipopolysaccharide to stimulate vascular endothelial cells and explored the effects of hydrogen-rich medium on the regulation of adhesion of monocytes to endothelial cells and vascular endothelial permeability. We found that hydrogen-rich medium could inhibit adhesion of monocytes to endothelial cells and decrease levels of adhesion molecules, whereas the levels of transepithelial/endothelial electrical resistance values and the expression of vascular endothelial cadherin were increased after hydrogen-rich medium treatment. Moreover, hydrogen-rich medium could lessen the expression of ROCK, as a similar effect of its inhibitor Y-27632. In addition, hydrogen-rich medium could also inhibit adhesion of polymorphonuclear neutrophils to endothelial cells. In conclusion, hydrogen-rich medium could regulate adhesion of monocytes/polymorphonuclear neutrophils to endothelial cells and vascular endothelial permeability, and this effect might be related to the decreased expression of ROCK protein. PMID:25895142

  12. Expression of cell-cell and cell-matrix adhesion proteins by sinusoidal endothelial cells in the normal and cirrhotic human liver.

    PubMed Central

    Couvelard, A.; Scoazec, J. Y.; Feldmann, G.

    1993-01-01

    We compared the expression of cell-cell and cell-matrix adhesion proteins by sinusoidal endothelial cells in normal human liver, in which the endothelial lining of hepatic sinusoids is discontinuous and devoid of basement membrane, and in cirrhosis, during which sinusoids might undergo a process of capillarization and acquire a continuous lining and a typical basement membrane. In normal liver, sinusoidal endothelial cells displayed a very restricted repertory of cell-adhesion molecules: the intercellular adhesion molecules PECAM-1 and CD34 were undetectable and only two integrins, alpha 1 beta 1 and alpha 5 beta 1, were present, whereas the laminin receptors alpha 6 beta 1 and alpha 2 beta 1 were undetectable and the beta 3 integrins were faintly expressed. In capillarized sinusoids, sinusoidal endothelial cells displayed striking changes in their repertory of cell-adhesion molecules, including the expression of PECAM-1 protein and messenger RNAs and the induction of the laminin receptors alpha 6 beta 1 and alpha 2 beta 1. Such changes co-localized with subendothelial laminin deposits. In conclusion, normal sinusoidal endothelial cells express a distinctive set of cell-adhesion molecules, adapted to their structural and microenvironmental characteristics, and this repertory is dramatically modified during sinusoidal capillarization, possibly as a consequence of the concomitant matrix changes. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 PMID:8362973

  13. Modulation of endothelial cell adhesion to synthetic vascular grafts using biotinylated fibronectin in a dual ligand protein system

    NASA Astrophysics Data System (ADS)

    Anamelechi, Charles Chibuzor

    Over half a million coronary artery bypass operations are performed annually in the US yielding an annual health care cost of over 16 billion dollars. Only five percent of bypasses are repeat operations in spite of the procedures prevalence. Patients facing repeat coronary artery bypass operations often lack transplantable autologous arteries or veins, necessitating the use of substitutes. Unfortunately, synthetic small diameter vascular grafts have unacceptable patency rates, primarily due to lumenal thrombus formation and intimal thickening. Endothelial cells (EC) mediate the anti-thrombotic activity in healthy blood vessels, and due to the scarcity of suitable autologous vascular replacement, EC-seeded small diameter synthetic vascular grafts represent a clear, immediate, and practical solution. The fundamental goal of this project was to optimize the dual ligand (DL) system on synthetic vascular graft (SVG) surrogates to show enhanced cell adhesion, retention, and native functionality compared to fibronectin alone. Initially, two SVG surrogates were identified through characterization by x-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and 125I radiolabeling. The first modification to the DL system involved direct biotinylation of fibronectin (bFN) as a replacement for co-adsorption of FN with biotinylated bovine serum albumin (bBSA). This was analyzed with a Langmuir model using surface plasmon resonance (SPR) spectroscopy to verify the binding affinity of bFN and ELISA to detect the availability of the RGD binding motif post biotinylation. The second major change in this project examined cell binding and formation of focal adhesion after shifting from direct incubation of HUVECs with RGD-SA to sequentially adsorbing bFN(9) and RGD-SA prior to introducing unmodified HUVECs. These experiments were conducted under static seeding conditions. Next, dynamic cell seeding onto the sequentially adsorbed protein surface was examined as a function of surface immobilized protein and Trypsin/EDTA concentration. SPR results showed statistical differences in alpha5beta1 and alphanubeta3 integrin binding to RGD cell binding motifs introduced by bFN(9) and RGD-SA. Increase in binding specificity through these integrins lead to rapid cell binding and retention on Teflon-AF surfaces adsorbed with this protein formulation. This system appears to be the nexus at which the DL has proven its value. These results could have broader implications in augmenting EC attachment to SVG prior to implantation.

  14. Homology modeling of an immunoglobulin-like domain in the Saccharomyces cerevisiae adhesion protein alpha-agglutinin.

    PubMed Central

    Lipke, P. N.; Chen, M. H.; de Nobel, H.; Kurjan, J.; Kahn, P. C.

    1995-01-01

    The Saccharomyces cerevisiae adhesion protein alpha-agglutinin is expressed by cells of alpha mating type. On the basis of sequence similarities, alpha-agglutinin has been proposed to contain variable-type immunoglobulin-like (IgV) domains. The low level of sequence similarity to IgV domains of known structure made homology modeling using standard sequence-based alignment algorithms impossible. We have therefore developed a secondary structure-based method that allowed homology modeling of alpha-aggulutinin domain III, the domain most similar to IgV domains. The model was assessed and where necessary refined to accommodate information obtained by biochemical and molecular genetic approaches, including the positions of a disulfide bond, glycosylation sites, and proteolytic sites. The model successfully predicted surface exposure of glycosylation and proteolytic sites, as well as identifying residues essential for binding activity. One side of the domain was predicted to be covered by carbohydrate residues. Surface accessibility and volume packing analyses showed that the regions of the model that have greatest sequence dissimilarity from the IgV consensus sequence are poorly structured in the biophysical sense. Nonetheless, the utility of the model suggests that these alignment and testing techniques should be of general use for building and testing of models of proteins that share limited sequence similarity with known structures. PMID:8535254

  15. Adhesive protein-free synthetic hydrogels for retinal pigment epithelium cell culture with low ROS level.

    PubMed

    Chen, Yong Mei; Liu, Zhen Qi; Feng, Zhi Hui; Xu, Feng; Liu, Jian Kang

    2014-07-01

    Engineering of human retinal pigment epithelium (RPE) cell monolayer with low level of reactive oxygen species (ROS) is important for regenerative RPE-based therapies. However, it is still challenging to culture RPE monolayer with low ROS level on soft substrates in vitro. To address this, we developed cytocompatible hydrogels to culture human RPE cell monolayer for future use in regenerative RPE-based therapies. The cell adhesion, proliferation, monolayer formation, morphology, survival, and ROS level of human ARPE-19 cells cultured on the surfaces of negatively charged poly (2-acrylamido-2-methyl propane sulfonic sodium) (PNaAMPS) and neutral poly(N,N-dimethylacrylamide) (PDMAAm) hydrogels with different stiffness were investigated. The importance of hydrogel stiffness on the cell function was firstly highlighted on the base of determined optimal Young's modulus for cultivation of RPE cell monolayer with relatively low ROS level. The construction of RPE cell monolayer with low ROS level on the PNaAMPS hydrogel may hold great potential as promising candidates for transplantation of RPE cell monolayer-hydrogel construct into the subretinal space to repair retinal functions. PMID:23913900

  16. The Ras suppressor Rsu-1 binds to the LIM 5 domain of the adaptor protein PINCH1 and participates in adhesion-related functions

    SciTech Connect

    Dougherty, Gerard W. [Department of Pathology, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, B3122, Bethesda, MD 20814 (United States); Section on Structural Cell Biology, National Institute on Deafness and Communication Disorders (NIDCD), NIH, Bethesda, MD 20892 (United States); Chopp, Treasa [Department of Pathology, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, B3122, Bethesda, MD 20814 (United States); Qi Shengmei [Department of Pathology, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, B3122, Bethesda, MD 20814 (United States); Cutler, Mary Lou [Department of Pathology, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, B3122, Bethesda, MD 20814 (United States)]. E-mail: mcutler@usuhs.mil

    2005-05-15

    Rsu-1 is a highly conserved leucine rich repeat (LRR) protein that is expressed ubiquitously in mammalian cells. Rsu-1 was identified based on its ability to inhibit transformation by Ras, and previous studies demonstrated that ectopic expression of Rsu-1 inhibited anchorage-independent growth of Ras-transformed cells and human tumor cell lines. Using GAL4-based yeast two-hybrid screening, the LIM domain protein, PINCH1, was identified as the binding partner of Rsu-1. PINCH1 is an adaptor protein that localizes to focal adhesions and it has been implicated in the regulation of adhesion functions. Subdomain mapping in yeast revealed that Rsu-1 binds to the LIM 5 domain of PINCH1, a region not previously identified as a specific binding domain for any other protein. Additional testing demonstrated that PINCH2, which is highly homologous to PINCH1, except in the LIM 5 domain, does not interact with Rsu-1. Glutathione transferase fusion protein binding studies determined that the LRR region of Rsu-1 interacts with PINCH1. Transient expression studies using epitope-tagged Rsu-1 and PINCH1 revealed that Rsu-1 co-immunoprecipitated with PINCH1 and colocalized with vinculin at sites of focal adhesions in mammalian cells. In addition, endogenous P33 Rsu-1 from 293T cells co-immunoprecipitated with transiently expressed myc-tagged PINCH1. Furthermore, RNAi-induced reduction in Rsu-1 RNA and protein inhibited cell attachment, and while previous studies demonstrated that ectopic expression of Rsu-1 inhibited Jun kinase activation, the depletion of Rsu-1 resulted in activation of Jun and p38 stress kinases. These studies demonstrate that Rsu-1 interacts with PINCH1 in mammalian cells and functions, in part, by altering cell adhesion.

  17. The Plasmodium vivax homolog of the ookinete adhesive micronemal protein, CTRP.

    PubMed

    Kaneko, Osamu; Templeton, Thomas J; Iriko, Hideyuki; Tachibana, Mayumi; Otsuki, Hitoshi; Takeo, Satoru; Sattabongkot, Jetsumon; Torii, Motomi; Tsuboi, Takafumi

    2006-09-01

    The Plasmodium circumsporozoite protein/thrombospondin-related anonymous protein-related protein (CTRP) is expressed at the mosquito midgut ookinete stage and is considered to be a transmission-blocking vaccine candidate. CTRP is composed of multiple von Willebrand factor A (vWA) and thrombospondin type 1 domains in the extracellular portion of the molecule, and a short acidic cytoplasmic domain that interacts with the actomyosin machinery. As a means to predict functionally relevant domains within CTRP we determined the nucleotide sequences of CTRP from the Plasmodium vivax Sall and the Plasmodium yoelii 17XL strains and characterized the conservation of domain architectures and motifs across Plasmodium genera. Sequence alignments indicate that the CTRP 1st to 4th vWA domains exhibit greater conservation, and thereby are perhaps functionally more important than the 5th and 6th domains. This point should be considered for the development of a transmission-blocking vaccine that includes CTRP recombinant subunit. To complement previous cellular studies on CTRP, we further determined the expression and cellular localization of CTRP protein in P. vivax and P. yoelii. PMID:16822707

  18. The human poliovirus receptor related 2 protein is a new hematopoietic/endothelial homophilic adhesion molecule.

    PubMed

    Lopez, M; Aoubala, M; Jordier, F; Isnardon, D; Gomez, S; Dubreuil, P

    1998-12-15

    We have recently described Poliovirus Receptor Related 2 (PRR2), a new cell surface molecule homologous to the poliovirus receptor (PVR/CD155). Both molecules are transmembrane glycoproteins belonging to the Ig superfamily (IgSF). They contain 3 Ig domains of V, C2, and C2 types in their extracellular regions that share 51% aa identity. The PRR2 gene encodes two mRNA isoforms of 3.0 kb (hPRR2 [short form]) and 4.4 kb (hPRR2delta [long form]), both widely expressed in human tissues, including hematopoietic cells. To further characterize PRR2 expression during hematopoiesis and to analyze its function, we have developed a monoclonal antibody (MoAb) directed against its extracellular region (R2.477). PRR2 was expressed in 96% of the CD34(+), 88% of the CD33(+), and 95% of the CD14(+) hematopoietic lineages and faintly in the CD41 compartment. Ectopic expression of both PRR2 cDNAs induced marked cell aggregation. A soluble chimeric receptor construct with the Fc fragment of human IgG1 (PRR2-Fc) as well as a fab fragment of the anti-PRR2 MoAb (R2.477) inhibit aggregation. PRR2-Fc binds specifically to PRR2-expressing cells. These results suggest that PRR2 is a homophilic adhesion receptor. PRR2 was also expressed at the surface of endothelial cells at the intercellular junctions of adjacent cells but not at the free cellular edges. Homophilic interactions are associated with dimerization of isoforms of PRR2 and lead to the tyrosine phosphorylation of PRR2delta. Altogether, these results suggest that homophilic properties of PRR2 could participate to the regulation of hematopoietic/endothelial cell functions. PMID:9845526

  19. Influence of poly(ethylene oxide)-based copolymer on protein adsorption and bacterial adhesion on stainless steel: modulation by surface hydrophobicity.

    PubMed

    Yang, Yi; Rouxhet, Paul G; Chudziak, Dorota; Telegdi, Judit; Dupont-Gillain, Christine C

    2014-06-01

    The aim of the present work is to study the adhesion of Pseudomonas NCIMB 2021, a typical aerobic marine microorganism, on stainless steel (SS) substrate. More particularly, the potential effect on adhesion of adsorbed poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) triblock copolymer is investigated. Bacterial attachment experiments were carried out using a modified parallel plate flow chamber, allowing different surface treatments to be compared in a single experiment. The amount of adhering bacteria was determined via DAPI staining and fluorescence microscopy. X-ray photoelectron spectroscopy (XPS) was used to characterize the surface chemical composition of SS and hydrophobized SS before and after PEO-PPO-PEO adsorption. The adsorption of bovine serum albumin (BSA), a model protein, was investigated to test the resistance of PEO-PPO-PEO layers to protein adsorption. The results show that BSA adsorption and Pseudomonas 2021 adhesion are significantly reduced on hydrophobized SS conditioned with PEO-PPO-PEO. Although PEO-PPO-PEO is also found to adsorb on SS, it does not prevent BSA adsorption nor bacterial adhesion, which is attributed to different PEO-PPO-PEO adlayer structures on hydrophobic and hydrophilic surfaces. The obtained results open the way to a new strategy to reduce biofouling on metal oxide surfaces using PEO-PPO-PEO triblock copolymer. PMID:24650936

  20. Protein N-glycosylation in oral cancer: Dysregulated cellular networks among DPAGT1, E-cadherin adhesion and canonical Wnt signaling

    PubMed Central

    Varelas, Xaralabos; Bouchie, Meghan P; Kukuruzinska, Maria A

    2014-01-01

    N-Linked glycosylation (N-glycosylation) of proteins has long been associated with oncogenesis, but not until recently have the molecular mechanisms underlying this relationship begun to be unraveled. Here, we review studies describing how dysregulation of the N-glycosylation-regulating gene, DPAGT1, drives oral cancer. DPAGT1 encodes the first and rate-limiting enzyme in the assembly of the lipid-linked oligosaccharide precursor in the endoplasmic reticulum and thus mediates N-glycosylation of many cancer-related proteins. DPAGT1 controls N-glycosylation of E-cadherin, the major epithelial cell–cell adhesion receptor and a tumor suppressor, thereby affecting intercellular adhesion and cytoskeletal dynamics. DPAGT1 also regulates and is regulated by Wnt/?-catenin signaling, impacting the balance between proliferation and adhesion in homeostatic tissues. Thus, aberrant induction of DPAGT1 promotes a positive feedback network with Wnt/?-catenin that represses E-cadherin-based adhesion and drives tumorigenic phenotypes. Further, modification of receptor tyrosine kinases (RTKs) with N-glycans is known to control their surface presentation via the galectin lattice, and thus increased DPAGT1 expression likely contributes to abnormal activation of RTKs in oral cancer. Collectively, these studies suggest that dysregulation of the DPAGT1/Wnt/E-cadherin network underlies the etiology and pathogenesis of oral cancer. PMID:24742667

  1. Protein adsorption and cell adhesion on three-dimensional polycaprolactone scaffolds with respect to plasma modification by etching and deposition techniques

    NASA Astrophysics Data System (ADS)

    Myung, Sung Woon; Ko, Yeong Mu; Kim, Byung Hoon

    2014-11-01

    In this work, protein adsorption and cell adhesion on three-dimensional (3D) polycaprolactone (PCL) scaffolds treated by plasma etching and deposition were performed. The 3D PCL scaffold used as a substrate of a bone tissue was fabricated by recent rapid prototype techniques. To increase surface properties, such as hydrophilicity, roughness, and surface chemistry, through good protein adhesion on scaffolds, oxygen (O2) plasma etching and acrylic acid or allyamine plasma deposition were performed on the 3D PCL scaffolds. The O2 plasma etching induced the formation of random nanoporous structures on the roughened surfaces of the 3D PCL scaffolds. The plasma deposition with acrylic acid and allyamine induced the chemical modification for introducing a functional group. The protein adsorption increased on the O2 plasma-etched surface compared with an untreated 3D PCL scaffold. MC3T3-E1 cells adhered bioactively on the etched and deposited surface compared with the untreated surface. The present plasma modification might be sought as an effective technique for enhancing protein adsorption and cell adhesion.

  2. Effects of RGDS sequence genetically interfused in the silk fibroin light chain protein on chondrocyte adhesion and cartilage synthesis

    Microsoft Academic Search

    Yusuke Kambe; Koji Yamamoto; Katsura Kojima; Yasushi Tamada; Naohide Tomita

    2010-01-01

    Initial chondrocyte–silk fibroin interactions are implicated in chondrogenesis when using fibroin as a scaffold for chondrocytes. Here, we focused on integrin-mediated cell–scaffold adhesion and prepared cell adhesive fibroin in which a tandem repeat of the Arg-Gly-Asp-Ser (RGDS) sequence was genetically interfused in the fibroin light chain (L-chain) (L-RGDS×2 fibroin). We investigated the effects of the sequence on chondrocyte adhesion and

  3. Novel Modulator for Endothelial Adhesion Molecules Adipocyte-Derived Plasma Protein Adiponectin

    Microsoft Academic Search

    Noriyuki Ouchi; Shinji Kihara; Yukio Arit; Kazuhisa Maeda; Hiroshi Kuriyama; Yoshihisa Okamoto; Kikuko Hott; Makoto Nishida; Masahiko Takahashi; Tadashi Nakamura; Shizuya Yamashita; Tohru Funahashi; Yuji Matsuzawa

    Background—Among the many adipocyte-derived endocrine factors, we recently found an adipocyte-specific secretory protein, adiponectin, which was decreased in obesity. Although obesity is associated with increased cardiovascular mortality and morbidity, the molecular basis for the link between obesity and vascular disease has not been fully clarified. The present study investigated whether adiponectin could modulate endothelial function and relate to coronary disease.

  4. Adrm1, a Putative Cell Adhesion Regulating Protein, is a Novel Proteasome-associated Factor

    Microsoft Academic Search

    Jakob Ploug Jørgensen; Anne-Marie Lauridsen; Poul Kristensen; Karen Dissing; Anders H. Johnsen; Klavs B. Hendil; Rasmus Hartmann-Petersen

    2006-01-01

    We have identified Adrm1 as a novel component of the regulatory ATPase complex of the 26 S proteasome: Adrm1 was precipitated with an antibody to proteasomes and vice versa. Adrm1 co-migrated with proteasomes on gel-filtration chromatography and non-denaturing polyacrylamide gel electrophoresis. Adrm1 has been described as an interferon-?-inducible, heavily glycosylated membrane protein of 110 kDa. However, we found Adrm1 in mouse

  5. Titanate nanowire scaffolds decorated with anatase nanocrystals show good protein adsorption and low cell adhesion capacity

    PubMed Central

    Ding, Xianglong; Yang, Xiaoqin; Zhou, Lei; Lu, Haibin; Li, Shaobing; Gao, Yan; Lai, Chunhua; Jiang, Ying

    2013-01-01

    Background and methods: In this report, layered microporous titanate nanowire scaffolds (TiNWs) were constructed via a hydrothermal route and then decorated with anatase nanocrystals (ANs@TiNWs) by immersion in TiCl4 solution. The diameter and specific surface area of the ANs@TiNWs was measured. The TiNWs and ANs@TiNWs were then compared for their ability to adsorb protein and adhere to MG63 cells. Results: The diameter and specific surface area of the ANs@TiNWs were significantly larger than for TiNWs, and the ANs@TiNWs had an enhanced protein-adsorbing effect. It was found that the MG63 cells were less able to adhere to the flat titanium substrate than the TiNWs and ANs@TiNWs, and that this cell-repellant ability was greater with ANs@TiNWs. Other MG63 cell functions, proliferation in particular, were also inhibited by ANs@TiNWs. Conclusion: ANs@TiNWs show a high protein adsorption and cell-repellant capacity which would be useful in drug delivery. PMID:23430236

  6. Seafood delicacy makes great adhesive

    SciTech Connect

    Idaho National Laboratory - Frank Roberto, Heather Silverman

    2008-03-26

    Technology from Mother Nature is often hard to beat, so Idaho National Laboratory scientistsgenetically analyzed the adhesive proteins produced by blue mussels, a seafood delicacy. Afterobtaining full-length DNA sequences encoding these proteins, reprod

  7. The adhesion G protein-coupled receptor GPR56 is a cell-autonomous regulator of oligodendrocyte development

    PubMed Central

    Giera, Stefanie; Deng, Yiyu; Luo, Rong; Ackerman, Sarah D.; Mogha, Amit; Monk, Kelly R.; Ying, Yanqin; Jeong, Sung-Jin; Makinodan, Manabu; Bialas, Allison R.; Chang, Bernard S.; Stevens, Beth; Corfas, Gabriel; Piao, Xianhua

    2015-01-01

    Mutations in GPR56, a member of the adhesion G protein-coupled receptor family, cause a human brain malformation called bilateral frontoparietal polymicrogyria (BFPP). Magnetic resonance imaging (MRI) of BFPP brains reveals myelination defects in addition to brain malformation. However, the cellular role of GPR56 in oligodendrocyte development remains unknown. Here, we demonstrate that loss of Gpr56 leads to hypomyelination of the central nervous system in mice. GPR56 levels are abundant throughout early stages of oligodendrocyte development, but are downregulated in myelinating oligodendrocytes. Gpr56-knockout mice manifest with decreased oligodendrocyte precursor cell (OPC) proliferation and diminished levels of active RhoA, leading to fewer mature oligodendrocytes and a reduced number of myelinated axons in the corpus callosum and optic nerves. Conditional ablation of Gpr56 in OPCs leads to a reduced number of mature oligodendrocytes as seen in constitutive knockout of Gpr56. Together, our data define GPR56 as a cell-autonomous regulator of oligodendrocyte development. PMID:25607655

  8. A family of ROP proteins that suppresses actin dynamics, and is essential for polarized growth and cell adhesion.

    PubMed

    Burkart, Graham M; Baskin, Tobias I; Bezanilla, Magdalena

    2015-07-15

    In plants, the ROP family of small GTPases has been implicated in the polarized growth of tip-growing cells, such as root hairs and pollen tubes; however, most of the data derive from overexpressing ROP genes or constitutively active and dominant-negative isoforms, whereas confirmation by using loss-of-function studies has generally been lacking. Here, in the model moss Physcomitrella patens, we study ROP signaling during tip growth by using a loss-of-function approach based on RNA interference (RNAi) to silence the entire moss ROP family. We find that plants with reduced expression of ROP genes, in addition to failing to initiate tip growth, have perturbed cell wall staining, reduced cell adhesion and have increased actin-filament dynamics. Although plants subjected to RNAi against the ROP family also have reduced microtubule dynamics, this reduction is not specific to loss of ROP genes, as it occurs when actin function is compromised chemically or genetically. Our data suggest that ROP proteins polarize the actin cytoskeleton by suppressing actin-filament dynamics, leading to an increase in actin filaments at the site of polarized secretion. PMID:26045445

  9. Hydrogels based on poly(ethylene oxide) and poly(tetramethylene oxide) or poly(dimethyl siloxane): synthesis, characterization, in vitro protein adsorption and platelet adhesion

    Microsoft Academic Search

    Jae Hyung Park; You Han Bae

    2002-01-01

    In vitro protein adsorption, platelet adhesion and activation on new hydrogel surfaces, composed of poly(ethylene oxide) (PEO) and poly(tetramethylene oxide) (PTMO) or poly(dimethyl siloxane) (PDMS), were investigated. By varying PEO length (MW=2000 or 3400), hydrophobic components (PTMO or PDMS) or polymer topology (block or graft copolymers), various physical hydrogels were produced. Their structures were verified by 1HNMR and ATR-IR and

  10. Epidemiological survey of Babesia gibsoni infection in dogs in Japan by enzyme-linked immunosorbent assay using B. gibsoni thrombospondin-related adhesive protein antigen

    Microsoft Academic Search

    Kenji Konishi; Yoshimi Sakata; Naomi Miyazaki; Honglin Jia; Youn-Kyoung Goo; Xuenan Xuan; Hisashi Inokuma

    2008-01-01

    A nationwide epidemiological survey of Babesia gibsoni infection in non-fighting dogs was conducted using an improved ELISA with recombinant B. gibsoni thrombospondin-related adhesive protein (BgTRAP). A total of 1206 dogs from 27 prefectures were examined and 128 (10.6%) tested positive. In the eastern part of Japan, 39 dogs out of the 559 (7.0%) examined were positive, while 89 dogs out

  11. Epstein–Barr Virus Latent Membrane Protein1 Induction by Histone Deacetylase Inhibitors Mediates Induction of Intercellular Adhesion Molecule1 Expression and Homotypic Aggregation

    Microsoft Academic Search

    Jae Hong Park; Douglas V. Faller

    2002-01-01

    Epstein–Barr virus (EBV) latent membrane protein (LMP)-1 induces B lymphocyte immortalization and activates constitutive signal transduction, including NF-?B, JNK\\/p38, and JAK\\/STAT pathways. During EBV latency, LMP-1 expression induces several B lymphocyte activation markers, including intercellular adhesion molecule (ICAM)-1. We found that various structurally distinct histone deacetylase inhibitors (HDACI), as well as phorbol ester treatment, induced homotypic aggregation in EBV-positive Burkitt's

  12. The Neural Cell Adhesion Molecule Regulates Cell-Surface Delivery of G-Protein-Activated Inwardly Rectifying Potassium Channels Via Lipid Rafts

    Microsoft Academic Search

    Markus Delling; Erhard Wischmeyer; Alexander Dityatev; Vladimir Sytnyk; Rudiger W. Veh; Andreas Karschin; Melitta Schachner

    2002-01-01

    Mice deficient in the neural cell adhesion molecule (NCAM) exhibit increased anxiety and anxiolytic sensitivity to serotonin 5-HT1A receptor agonists. Here, we investigate the relationship between NCAM and 5-HT1A receptor signaling pathways mod- ulating G-protein-activated inwardly rectifying K (Kir3) chan- nels. When studying this relationship in cultured hippocampal neurons, we observed that in cells from NCAM-deficient mice, inwardly rectifying K

  13. Plasmodium falciparum Erythrocyte Membrane Protein 1 is a Parasitized Erythrocyte Receptor for Adherence to CD36, Thrombospondin, and Intercellular Adhesion Molecule 1

    Microsoft Academic Search

    D. I. Baruch; J. A. Gormley; C. Ma; R. J. Howard; B. L. Pasloske

    1996-01-01

    Adherence of mature Plasmodium falciparum parasitized erythrocytes (PRBCs) to microvascular endothelium contributes directly to acute malaria pathology. We affinity purified molecules from detergent extracts of surface-radioiodinated PRBCs using several endothelial cell receptors known to support PRBC adherence, including CD36, thrombospondin (TSP), and intercellular adhesion molecule 1 (ICAM-1). All three host receptors affinity purified P. falciparum erythrocyte membrane protein 1 (PfEMP1),

  14. Peroxinectin, a cell adhesive protein associated with the proPO system from the black tiger shrimp, Penaeus monodon

    Microsoft Academic Search

    K. Sritunyalucksana; K. Wongsuebsantati; M. W. Johansson; K. Söderhäll

    2001-01-01

    Upon activation of the prophenoloxidase activating system in the shrimp, Penaeus monodon, a cell adhesion activity in the haemolymph is generated. A cell adhesion assay showed that a high number of granular cells (60%) adhered to coverslips coated with a shrimp haemocyte lysate supernatant, whereas a very low number of cells adhered to coverslips coated with bovine serum albumin. Inhibition

  15. Talin-1 and kindlin-3 regulate alpha4beta1 integrin-mediated adhesion stabilization, but not G protein-coupled receptor-induced affinity upregulation.

    PubMed

    Hyduk, Sharon J; Rullo, Jacob; Cano, Adrianet Puig; Xiao, Haiyan; Chen, Mian; Moser, Markus; Cybulsky, Myron I

    2011-10-15

    Chemokine/chemoattractant G protein-coupled receptors trigger an inside-out signaling network that rapidly activates integrins, a key step in inflammatory leukocyte recruitment. Integrins mediate leukocyte arrest and adhesion to endothelium through multivalent binding, and they transmit outside-in signals to stabilize adhesion and coordinate cell spreading and migration. In the present study, we used RNA interference in the U937 monocytic cell line to investigate the role of talin-1, kindlin-3, and ?-actinin-1 in the fMLF- and SDF-1?-induced upregulation of ?(4)?(1) integrin affinity and consequent adhesive events. Affinity upregulation of ?(4)?(1) integrin was not impaired by small interfering RNA knockdown of talin-1, kindlin-3, or ?-actinin-1. Only kindlin-3 knockdown increased flow-induced detachment from VCAM-1-coated surfaces in response to fluid flow, whereas knockdown of either talin-1 or kindlin-3 increased detachment from ICAM-1-coated surfaces. Biochemical analyses revealed that ?(4)?(1) expression was highly enriched in U937 cell microridges and murine lymphocyte microvilli. Kindlin-3 was present throughout the cell, whereas talin-1 was largely excluded from microridges/microvilli. The subcellular colocalization of ?(4)?(1) and kindlin-3 in microridges may explain why kindlin-3 rapidly associates with ?(4)?(1) after G protein-coupled receptor signaling and contributes to adhesion strengthening. Talin-1 contributed to ?(4)?(1)-dependent chemotaxis, suggesting that it participates in a later stage of the leukocyte adhesion cascade when the leukocyte cytoskeleton undergoes dramatic rearrangement. PMID:21911599

  16. Mechanism underlying bioinertness of self-assembled monolayers of oligo(ethyleneglycol)-terminated alkanethiols on gold: protein adsorption, platelet adhesion, and surface forces.

    PubMed

    Hayashi, Tomohiro; Tanaka, Yusaku; Koide, Yuki; Tanaka, Masaru; Hara, Masahiko

    2012-08-01

    The mechanism underlying the bioinertness of the self-assembled monolayers of oligo(ethylene glycol)-terminated alkanethiol (OEG-SAM) was investigated with protein adsorption experiments, platelet adhesion tests, and surface force measurements with an atomic force microscope (AFM). In this work, we performed systematic analysis with SAMs having various terminal groups (-OEG, -OH, -COOH, -NH(2), and -CH(3)). The results of the protein adsorption experiment by the quartz crystal microbalance (QCM) method suggested that having one EG unit and the neutrality of total charges of the terminal groups are essential for protein-resistance. In particular, QCM with energy dissipation analyses indicated that proteins absorb onto the OEG-SAM via a very weak interaction compared with other SAMs. Contrary to the protein resistance, at least three EG units as well as the charge neutrality of the SAM are found to be required for anti-platelet adhesion. When the identical SAMs were formed on both AFM probe and substrate, our force measurements revealed that only the OEG-SAMs possessing more than two EG units showed strong repulsion in the range of 4 to 6 nm. In addition, we found that the SAMs with other terminal groups did not exhibit such repulsion. The repulsion between OEG-SAMs was always observed independent of solution conditions [NaCl concentration (between 0 and 1 M) and pH (between 3 and 11)] and was not observed in solution mixed with ethanol, which disrupts the three-dimensional network of the water molecules. We therefore concluded that the repulsion originated from structured interfacial water molecules. Considering the correlation between the above results, we propose that the layer of the structured interfacial water with a thickness of 2 to 3 nm (half of the range of the repulsion observed in the surface force measurements) plays an important role in deterring proteins and platelets from adsorption or adhesion. PMID:22717889

  17. Effects of RGDS sequence genetically interfused in the silk fibroin light chain protein on chondrocyte adhesion and cartilage synthesis.

    PubMed

    Kambe, Yusuke; Yamamoto, Koji; Kojima, Katsura; Tamada, Yasushi; Tomita, Naohide

    2010-10-01

    Initial chondrocyte-silk fibroin interactions are implicated in chondrogenesis when using fibroin as a scaffold for chondrocytes. Here, we focused on integrin-mediated cell-scaffold adhesion and prepared cell adhesive fibroin in which a tandem repeat of the Arg-Gly-Asp-Ser (RGDS) sequence was genetically interfused in the fibroin light chain (L-chain) (L-RGDSx2 fibroin). We investigated the effects of the sequence on chondrocyte adhesion and cartilage synthesis, in comparison to the effects of fibronectin. As the physicochemical surface properties (e.g., wettability and zeta potential) of the fibroin substrate were not affected by the modification, specific cell adhesion to the RGDS predominately changed the chondrocyte adhesive state. This suggestion was also supported by the competitive inhibition of chondrocyte attachment to the L-RGDSx2 fibroin substrate with soluble RGD peptides in the medium. Unlike fibronectin, the expression of RGDS in the fibroin L-chain had no effect on chondrocyte spreading area but enhanced mRNA expression levels of integrins alpha5 and beta1, and aggrecan at 12 h after seeding. Although both the sequence and fibronectin increased cell adhesive force, chondrocytes grown on the fibroin substrate exhibited a peak in the force with time in culture. These results suggested that moderate chondrocyte adhesion to fibroin induced by the RGDS sequence was able to maintain the chondrogenic phenotype and, from the histology findings, the sequence could facilitate chondrogenesis. PMID:20643479

  18. Serum Vascular Adhesion Protein-1 Predicts 10-Year Cardiovascular and Cancer Mortality in Individuals With Type 2 Diabetes

    PubMed Central

    Li, Hung-Yuan; Jiang, Yi-Der; Chang, Tien-Jyun; Wei, Jung-Nan; Lin, Mao-Shin; Lin, Cheng-Hsin; Chiang, Fu-Tien; Shih, Shyang-Rong; Hung, Chi Sheng; Hua, Cyue-Huei; Smith, David J.; Vanio, Jani; Chuang, Lee-Ming

    2011-01-01

    OBJECTIVE Vascular adhesion protein-1 (VAP-1) participates in inflammation and catalyzes the breakdown of amines to produce aldehyde, hydrogen peroxide, and ammonia. Serum VAP-1 correlates positively with both acute hyperglycemia and diabetes. We conducted a cohort study to evaluate whether serum VAP-1 predicts 10-year survival in type 2 diabetic patients. RESEARCH DESIGN AND METHODS Between July 1996 and June 2003, we enrolled 661 type 2 diabetic subjects at National Taiwan University Hospital. Serum VAP-1 in the samples obtained at enrollment was measured by time-resolved immunofluorometric assay. The vital status of all subjects was ascertained by linking their data with computerized death certificates in Taiwan. RESULTS The medium follow-up period was 10.4 years. Subjects with serum VAP-1 in the highest tertile had a hazard ratio (HR) of 2.19 (95% CI 1.17–4.11) for all-cause mortality adjusted for age, sex, smoking, history of cardiovascular disease, obesity, hypertension, hemoglobin A1c, diabetes duration, total cholesterol, use of statins, abnormal ankle-brachial index, estimated glomerular filtration rate (eGFR), and proteinuria. The adjusted HRs for logarithmically transformed serum VAP-1 were 5.83 (95% CI 1.17–28.97) for cardiovascular mortality, 6.32 (95% CI 1.25–32.00) for mortality from cardiovascular and diabetic causes, and 17.24 (95% CI 4.57–65.07) for cancer mortality. There were four variables, including age, serum VAP-1, proteinuria, and eGFR, which could enhance mortality prediction significantly. CONCLUSIONS Serum VAP-1 can predict 10-year all-cause mortality, cardiovascular mortality, and cancer mortality independently in type 2 diabetic subjects. Serum VAP-1 is a novel biomarker that improves risk prediction over and above established risk factors. PMID:21282368

  19. Upregulation of adhesion complex proteins and fibronectin by human keratinocytes treated with an aqueous extract from the leaves of Chromolaena odorata (Eupolin).

    PubMed

    Phan, T T; Allen, J; Hughes, M A; Cherry, G; Wojnarowska, F

    2000-01-01

    The fresh leaves and extract of the plant Chromolaena odorata are a traditional herbal treatment in developing countries for burns, soft tissue wounds and skin infections. We have previously shown that the extract had an effect on the growth and proliferation of keratinocytes and fibroblasts in culture. This study has demonstrated that Eupolin extract increased expression of several components of the adhesion complex and fibronectin by human keratinocytes. Using indirect immunofluorescence we found increased expression (dose-dependent) of laminin 5, laminin 1, collagen IV, and fibronectin. The expression of the b1 and b4 integrins was upregulated by the extract at low concentrations (0.1 and 1 microg/ml), but the expression was decreased at higher doses of Eupolin (10 microg-150 microg/ml). A number of clinical studies carried out by Vietnamese and international medical investigators have demonstrated the efficacy of this extract on the wound healing process. In this study we have shown that Eupolin stimulated the expression of many proteins of the adhesion complex and fibronectin by human keratinocytes. The adhesion complex proteins are essential to stabilise epithelium and this effect could contribute to the clinical efficacy of Eupolin in healing. PMID:11056422

  20. Siglec-9 is a novel leukocyte ligand for Vascular Adhesion Protein-1 and can be utilized in PET-imaging of inflammation and cancer

    PubMed Central

    Kiss, Elina A.; Elima, Kati; Nymalm, Yvonne; Veres, Tibor Z.; Marttila-Ichihara, Fumiko; Elovaara, Heli; Saanijoki, Tiina; Crocker, Paul R.; Maksimow, Mikael; Bligt, Eva; Salminen, Tiina A.; Salmi, Marko; Roivainen, Anne; Jalkanen, Sirpa

    2013-01-01

    Leukocyte migration to sites of inflammation is regulated by several endothelial adhesion molecules. Vascular Adhesion Protein-1 (VAP-1) is unique among the homing-associated molecules as it is both an enzyme that oxidizes primary amines and an adhesin. Although granulocytes can bind to endothelium via a VAP-1 dependent manner, the counter-receptor(s) on this leukocyte population is not known. Here we used a phage display approach and identified Siglec-9 as a candidate ligand on granulocytes. The binding between Siglec-9 and VAP-1 was confirmed by in vitro and ex vivo adhesion assays. The interaction sites between VAP-1 and Siglec-9 were identified by molecular modeling and confirmed by further binding assays with mutated proteins. Although the binding takes place in the enzymatic groove of VAP-1, it is only partially dependent on the enzymatic activity of VAP-1. In positron emission tomography the 68Gallium- labeled peptide of Siglec-9 specifically detected VAP-1 in vasculature at sites of inflammation and cancer. Thus, the peptide binding to the enzymatic groove of VAP-1 can be used for imaging such conditions as inflammation and cancer. PMID:21821708

  1. Serine 34 Phosphorylation of Rho Guanine Dissociation Inhibitor (RhoGDI?) Links Signaling from Conventional Protein Kinase C to RhoGTPase in Cell Adhesion*

    PubMed Central

    Dovas, Athanassios; Choi, Youngsil; Yoneda, Atsuko; Multhaupt, Hinke A. B.; Kwon, Seung-Hae; Kang, Dongmin; Oh, Eok-Soo; Couchman, John R.

    2010-01-01

    Conventional protein kinase C (PKC) isoforms are essential serine/threonine kinases regulating many signaling networks. At cell adhesion sites, PKC? can impact the actin cytoskeleton through its influence on RhoGTPases, but the intermediate steps are not well known. One important regulator of RhoGTPase function is the multifunctional guanine nucleotide dissociation inhibitor RhoGDI? that sequesters several related RhoGTPases in an inactive form, but it may also target them through interactions with actin-associated proteins. Here, it is demonstrated that conventional PKC phosphorylates RhoGDI? on serine 34, resulting in a specific decrease in affinity for RhoA but not Rac1 or Cdc42. The mechanism of RhoGDI? phosphorylation is distinct, requiring the kinase and phosphatidylinositol 4,5-bisphosphate, consistent with recent evidence that the inositide can activate, localize, and orient PKC? in membranes. Phosphospecific antibodies reveal endogenous phosphorylation in several cell types that is sensitive to adhesion events triggered, for example, by hepatocyte growth factor. Phosphorylation is also sensitive to PKC inhibition. Together with fluorescence resonance energy transfer microscopy sensing GTP-RhoA levels, the data reveal a common pathway in cell adhesion linking two essential mediators, conventional PKC and RhoA. PMID:20472934

  2. Acute Activation of ?2-Adrenergic Receptor Regulates Focal Adhesions through ?Arrestin2- and p115RhoGEF Protein-mediated Activation of RhoA*

    PubMed Central

    Ma, Xiaojie; Zhao, Yu; Daaka, Yehia; Nie, Zhongzhen

    2012-01-01

    ?2-Adrenergic receptors (?2ARs) regulate cellular functions through G protein-transduced and ?Arrestin-transduced signals. ?2ARs have been shown to regulate cancer cell migration, but the underlying mechanisms are not well understood. Here, we report that ?2AR regulates formation of focal adhesions, whose dynamic remodeling is critical for directed cell migration. ?2ARs induce activation of RhoA, which is dependent on ?Arrestin2 but not Gs. ?Arrestin2 forms a complex with p115RhoGEF, a guanine nucleotide exchange factor for RhoA that is well known to be activated by G12/13-coupled receptors. Our results show that ?Arrestin2 forms a complex with p115RhoGEF in the cytosol in resting cells. Upon ?2AR activation, both ?Arrestin2 and p115RhoGEF translocate to the plasma membrane, with concomitant activation of RhoA and formation of focal adhesions and stress fibers. Activation of RhoA and focal adhesion remodeling may explain, at least in part, the role of ?2ARs in cell migration. These results suggest that ?Arrestin2 may serve as a convergence point for non-G12/13 and non-Gq protein-coupled receptors to activate RhoA. PMID:22500016

  3. Membrane protein glycosylation and CD44 content in the adhesion of human ovarian cancer cells to hyaluronan

    Microsoft Academic Search

    J. B. Catterall; L. M. H. Jones; G. A. Turner

    1999-01-01

    The adhesion of tumour cells to the hyaluronan (HA) pericellular coat of mesothelial cells is an important step in the peritoneal\\u000a spread of ovarian cancer. Previously, we have shown that the cell surface molecule CD44 is involved in this process. Paradoxically,\\u000a the degree of adhesion does not appear to be related to the amount of CD44 expressed. In order to

  4. The focal adhesion scaffolding protein HEF1 regulates activation of the Aurora-A and Nek2 kinases at the centrosome

    PubMed Central

    Pugacheva, Elena N.; Golemis, Erica A.

    2008-01-01

    Although HEF1 has a well-defined role in integrin-dependent attachment signaling at focal adhesions, it relocalizes to the spindle asters at mitosis. We report here that overexpression of HEF1 causes increase in centrosome numbers and multipolar spindles, resembling defects induced by manipulation of the mitotic regulatory kinase Aurora A (AurA). We show that HEF1 associates with and controls activation of AurA. We also show HEF1 depletion causes centrosomal splitting, monoastral spindles, and hyperactivation of Nek2, implying additional action earlier in cell cycle. These results provide new insights into the role of an adhesion protein in coordination of cell attachment and division. PMID:16184168

  5. The Src homology 2 protein Shb promotes cell cycle progression in murine hematopoietic stem cells by regulation of focal adhesion kinase activity

    SciTech Connect

    Gustafsson, Karin [Department of Medical Cell Biology, Uppsala University, Uppsala 751 23 (Sweden); Heffner, Garrett; Wenzel, Pamela L.; Curran, Matthew [HHMI, Children's Hospital Boston, Harvard Medical School, Boston, 02115 MA (United States); Grawé, Jan [Department of Genetics and Pathology, Uppsala University, Uppsala 75185 (Sweden); McKinney-Freeman, Shannon L. [Department of Hematology, St. Jude Children's Research Hospital, Memphis, TN 38105 (United States); Daley, George Q. [HHMI, Children's Hospital Boston, Harvard Medical School, Boston, 02115 MA (United States); Welsh, Michael, E-mail: michael.welsh@mcb.uu.se [Department of Medical Cell Biology, Uppsala University, Uppsala 751 23 (Sweden)

    2013-07-15

    The widely expressed adaptor protein Shb has previously been reported to contribute to T cell function due to its association with the T cell receptor and furthermore, several of Shb's known interaction partners are established regulators of blood cell development and function. In addition, Shb deficient embryonic stem cells displayed reduced blood cell colony formation upon differentiation in vitro. The aim of the current study was therefore to explore hematopoietic stem and progenitor cell function in the Shb knockout mouse. Shb deficient bone marrow contained reduced relative numbers of long-term hematopoietic stem cells (LT-HSCs) that exhibited lower proliferation rates. Despite this, Shb knockout LT-HSCs responded promptly by entering the cell cycle in response to genotoxic stress by 5-fluorouracil treatment. In competitive LT-HSC transplantations, Shb null cells initially engrafted as well as the wild-type cells but provided less myeloid expansion over time. Moreover, Shb knockout bone marrow cells exhibited elevated basal activities of focal adhesion kinase/Rac1/p21-activated kinase signaling and reduced responsiveness to Stem Cell Factor stimulation. Consequently, treatment with a focal adhesion kinase inhibitor increased Shb knockout LT-HSC proliferation. The altered signaling characteristics thus provide a plausible mechanistic explanation for the changes in LT-HSC proliferation since these signaling intermediates have all been shown to participate in LT-HSC cell cycle control. In summary, the loss of Shb dependent signaling in bone marrow cells, resulting in elevated focal adhesion kinase activity and reduced proliferative responses in LT-HSCs under steady state hematopoiesis, confers a disadvantage to the maintenance of LT-HSCs over time. -- Highlights: • Shb is an adaptor protein operating downstream of tyrosine kinase receptors. • Shb deficiency reduces hematopoietic stem cell proliferation. • The proliferative effect of Shb occurs via increased focal adhesion kinase activity. • Shb is critical for the long-term maintenance of the hematopoietic stem cell pool.

  6. RhoGAP68F controls transport of adhesion proteins in Rab4 endosomes to modulate epithelial morphogenesis of Drosophila leg discs.

    PubMed

    de Madrid, Beatriz Hernandez; Greenberg, Lina; Hatini, Victor

    2015-03-15

    Elongation and invagination of epithelial tissues are fundamental developmental processes that contribute to the morphogenesis of embryonic and adult structures and are dependent on coordinated remodeling of cell-cell contacts. The morphogenesis of Drosophila leg imaginal discs depends on extensive remodeling of cell contacts and thus provides a useful system with which to investigate the underlying mechanisms. The small Rho GTPase regulator RhoGAP68F has been previously implicated in leg morphogenesis. It consists of on an N-terminal Sec14 domain and a C-terminal GAP domain. Here we examined the molecular function and role of RhoGAP68F in epithelial remodeling. We find that depletion of RhoGAP68F impairs epithelial remodeling from a pseudostratified to simple, while overexpression of RhoGAP68F causes tears of lateral cell-cell contacts and thus impairs epithelial integrity. We show that the RhoGAP68F protein localizes to Rab4 recycling endosomes and forms a complex with the Rab4 protein. The Sec14 domain is sufficient for localizing to Rab4 endosomes, while the activity of the GAP domain is dispensable. RhoGAP68F, in turn, inhibits the scission and movement of Rab4 endosomes involved in transport the adhesion proteins Fasciclin3 and E-cadherin back to cell-cell contacts. Expression of RhoGAP68F is upregulated during prepupal development suggesting that RhoGAP68F decreases the transport of key adhesion proteins to the cell surface during this developmental stage to decrease the strength of adhesive cell-cell contacts and thereby facilitate epithelial remodeling and leg morphogenesis. PMID:25617722

  7. Platelet Adhesion

    Microsoft Academic Search

    Brian Savage; Zaverio M. Ruggeri

    Platelet adhesion and ensuing thrombus formation play a central role in normal hemostasis as well as in the pathogenesis of\\u000a acute coronary syndromes and thrombotic disorders. Circulating blood platelets adhere to sites of vascular injury through\\u000a specific adhesion receptors despite the hemodynamic forces in flowing blood that oppose adhesion contacts. At high shear,\\u000a this process is initiated by the reversible

  8. Streptococcus suis type 2 SSU0587 protein is a beta-galactosidase that contributes to bacterial adhesion but not to virulence in mice.

    PubMed

    Tang, Yulong; Zhang, Xiaoyan; Yin, Yulong; Hardwidge, Philip R; Fang, Weihuan

    2014-07-01

    Bacterial surface proteins play key roles in virulence and often contribute to bacterial adhesion and invasion. We discovered that the Streptococcus suis type 2 (SS2) gene SSU0587 encodes a protein of 1,491 amino acids that possesses ?-galactosidase activity. The surface association of the protein was dependent upon sortase activity. Deleting SSU0587 from clinical SS2 isolate JX081101 caused a loss of both ?-galactosidase activity and adherence to microvascular endothelial cells. Deleting SSU0587 had no measurable impact on either invasion of microvascular endothelial cells or on virulence in a murine infection model, although the concentration of JX081101?SSU0587 was reduced in the brains of infected mice, as compared with the pathogen loads of the wild-type strain. PMID:24670993

  9. Self-assembly of DNA and cell-adhesive proteins onto pH-sensitive inorganic crystals for precise and efficient transgene delivery.

    PubMed

    Chowdhury, E H

    2008-01-01

    Intracellular delivery of a functional gene or a gene-silencing DNA or RNA sequence is expected to be a powerful tool for treating critical human diseases very precisely and effectively. One of the major hurdles to the successful delivery of a nucleic acid with nanoparticles is the transport across the plasma membrane. The existence of various and numerous cell surface receptors with potential capability of being internalized by cells upon ligand binding unveils the ways of overcoming the barrier by targeting the nanoparticles to specific receptor. This review will reveal the current progress on utilizing the cell adhesion molecules as targeting receptors for transgene delivery, with a special focus on the design of bio-functionalized inorganic nanocrystals using both naturally occurring and genetically engineered cell adhesive proteins for high efficiency transfection of embryonic stem cells. Self-assembly of both DNA and cell-adhesive proteins, such as fibronectin and E-cadherin-Fc into the growing nanocrystals of carbonate apatite leads to their high affinity interactions with fibronectin-specific integrins and E-cadherin in embryonic stem cell surface and accelerates transgene delivery for subsequent expression. While only apatite nano-particles were very inefficient in transfecting embryonic stem cells, fibronectin-anchored particles and to a more significant extent, fibronectin and E-cadherin-Fc-associated particles dramatically enhanced transgene delivery with a value notably higher than that of commercially available lipofection system. Activation of protein kinase C (PKC) dramatically enhances transgene expression probably by up-regulating both integrin and E-cadherin. Thus, the new establishment of a bio-functional hybrid gene-carrier would promote and facilitate development of stem cell-based therapy in regenerative medicine. PMID:18781973

  10. The methyltransferase Ezh2 controls cell adhesion and migration through direct methylation of the extranuclear regulatory protein talin.

    PubMed

    Gunawan, Merry; Venkatesan, Nandini; Loh, Jia Tong; Wong, Jong Fu; Berger, Heidi; Neo, Wen Hao; Li, Liang Yao Jackson; La Win, Myint Khun; Yau, Yin Hoe; Guo, Tiannan; See, Peter Chi Ee; Yamazaki, Sayuri; Chin, Keh Chuang; Gingras, Alexandre R; Shochat, Susana Geifman; Ng, Lai Guan; Sze, Siu Kwan; Ginhoux, Florent; Su, I-Hsin

    2015-05-01

    A cytosolic role for the histone methyltransferase Ezh2 in regulating lymphocyte activation has been suggested, but the molecular mechanisms underpinning this extranuclear function have remained unclear. Here we found that Ezh2 regulated the integrin signaling and adhesion dynamics of neutrophils and dendritic cells (DCs). Ezh2 deficiency impaired the integrin-dependent transendothelial migration of innate leukocytes and restricted disease progression in an animal model of multiple sclerosis. Direct methylation of talin, a key regulatory molecule in cell migration, by Ezh2 disrupted the binding of talin to F-actin and thereby promoted the turnover of adhesion structures. This regulatory effect was abolished by targeted disruption of the interactions of Ezh2 with the cytoskeletal-reorganization effector Vav1. Our studies reveal an unforeseen extranuclear function for Ezh2 in regulating adhesion dynamics, with implications for leukocyte migration, immune responses and potentially pathogenic processes. PMID:25751747

  11. A functionalized poly(ethylene glycol)-based bioassay surface chemistry that facilitates bio-immobilization and inhibits non-specific protein, bacterial, and mammalian cell adhesion

    PubMed Central

    Harbers, Gregory M.; Emoto, Kazunori; Greef, Charles; Metzger, Steven W.; Woodward, Heather N.; Mascali, James J.; Grainger, David W.; Lochhead, Michael J.

    2008-01-01

    This paper describes a new bioassay surface chemistry that effectively inhibits non-specific biomolecular and cell binding interactions, while providing a capacity for specific immobilization of desired biomolecules. Poly(ethylene glycol) (PEG) as the primary component in nonfouling film chemistry is well-established, but the multicomponent formulation described here is unique in that it (1) is applied in a single, reproducible, solution-based coating step; (2) can be applied to diverse substrate materials without the use of special primers; and (3) is readily functionalized to provide specific attachment chemistries. Surface analysis data are presented, detailing surface roughness, polymer film thickness, and film chemistry. Protein non-specific binding assays demonstrate significant inhibition of serum, fibrinogen, and lysozyme adsorption to coated glass, indium tin oxide, and tissue culture polystyrene dishes. Inhibition of S. aureus and K. pneumoniae microbial adhesion in a microfluidic flow cell, and inhibition of fibroblast cell adhesion from serum-based cell culture is shown. Effective functionalization of the coating is demonstrated by directing fibroblast adhesion to polymer surfaces activated with an RGD peptide. Batch-to-batch reproducibility data are included. The in situ cross-linked PEG-based coating chemistry is unique in its formulation, and its surface properties are attractive for a broad range of in vitro bioassay applications. PMID:18815622

  12. Baicalein suppresses 17-?-estradiol-induced migration, adhesion and invasion of breast cancer cells via the G protein-coupled receptor 30 signaling pathway.

    PubMed

    Shang, Dandan; Li, Zheng; Zhu, Zhuxia; Chen, Huamei; Zhao, Lujun; Wang, Xudong; Chen, Yan

    2015-04-01

    Flavonoids are structurally similar to steroid hormones, particularly estrogens, and therefore have been studied for their potential effects on hormone-dependent cancers. Baicalein is the primary flavonoid derived from the root of Scutellaria baicalensis Georgi. In the present study, we investigated the effects of baicalein on 17?-estradiol (E2)-induced migration, adhesion and invasion of MCF-7 and SK-BR-3 breast cancer cells. The results demonstrated that baicalein suppressed E2-stimulated wound-healing migration and cell?Matrigel adhesion, and ameliorated E2-promoted invasion across a Matrigel-coated Transwell membrane. Furthermore, baicalein interfered with E2-induced novel G protein-coupled estrogen receptor (GPR30)-related signaling, including a decrease in tyrosine phosphorylation of epidermal growth factor receptor (EGFR) as well as phosphorylation of extracellular signal-regulated kinase (ERK) and serine/threonine kinase Akt, without affecting GPR30 expression. The results also showed that baicalein suppressed the expression of GPR30 target genes, cysteine-rich 61 (CYR61) and connective tissue growth factor (CTGF) induced by E2. Furthermore, baicalein prevented GPR30-related signaling activation and upregulation of CYR61 and CTGF mRNA levels induced by G1, a specific GPR 30 agonist. The results suggest that baicalein inhibits E2-induced migration, adhesion and invasion through interfering with GPR30 signaling pathway activation, which indicates that it may act as a therapeutic candidate for the treatment of GPR30-positive breast cancer metastasis. PMID:25672442

  13. The classic basic protein of myelin--conserved structural motifs and the dynamic molecular barcode involved in membrane adhesion and protein-protein interactions.

    PubMed

    Harauz, George; Libich, David S

    2009-06-01

    The myelin basic protein (MBP) family comprises a variety of developmentally-regulated members arising from different transcription start sites, differential splicing, and post-translational modifications. The "classic" isoforms of MBP include the 18.5 kDa form, which predominates in adult human myelin and facilitates compaction of the mature myelin sheath in the central nervous system, thereby maintaining its structural integrity. In addition to membrane-association, the 18.5 kDa and all other classic isoforms are able to interact with a multitude of proteins, including Ca(2+)-calmodulin, actin, tubulin, and SH3-domain containing proteins, and thus may be signalling linkers during myelin development and remodelling. All proteins in this family are intrinsically disordered, creating a large effective surface to facilitate multiple protein associations, and are post-translationally modified to various degrees by methylation, phosphorylation, and deimination. We have used spectroscopic (fluorescence, CD, EPR, and NMR) approaches to study MBP's conformational adaptability. A highly-conserved central domain presents an amphipathic alpha-helix in association with a phospholipid membrane, and contains a threonyl residue that is phosphorylated by MAP-kinases. In multiple sclerosis, this segment represents a primary immunodominant epitope. This helical structure is adjacent to a proline-rich region that presents a classic SH3-ligand, comprises a second MAP-kinase phosphorylation site, and forms a polyproline type II helix. This domain of the protein is thus essential to proper positioning of a protein-interaction motif, with the local conformation and accessibility being modulated by MAP-kinases. In addition, the C-terminus of 18.5 kDa MBP has been identified by NMR spectroscopy as a Ca(2+)-calmodulin-binding site, and is of note for having a high density of post-translational modifications (protein kinase C phosphorylation, and deimination). For the most part, any classic protein isoform functions as an entropic spring that interacts in its entirety with membranes and cytoskeletal proteins, but the central and C-terminal motifs may represent molecular switches. PMID:19519451

  14. Effects of the knockdown of death-associated protein 3 expression on cell adhesion, growth and migration in breast cancer cells.

    PubMed

    Wazir, Umar; Sanders, Andrew J; Wazir, Ahmad M A; Ye, Lin; Jiang, Wen G; Ster, Irina C; Sharma, Anup K; Mokbel, Kefah

    2015-05-01

    The death-associated protein 3 (DAP3) is a highly conserved phosphoprotein involved in the regulation of autophagy. A previous clinical study by our group suggested an association between low DAP3 expression and clinicopathological parameters of human breast cancer. In the present study, we intended to determine the role of DAP3 in cancer cell behaviour in the context of human breast cancer. We developed knockdown sub-lines of MCF7 and MDA-MB-231, and performed growth, adhesion, invasion assays and electric cell-substrate impedance sensing (ECIS) studies of post-wound migration of the cells. In addition, we studied the mRNA expression of caspase 8 and 9, death ligand signal enhancer (DELE), IFN-? promoter stimulator 1 (IPS1), cyclin D1 and p21 in the control and knockdown sub-lines. The knockdown sub-lines of MCF7 and MDA-MB-231 had significantly increased adhesion and decreased growth when compared to the controls. Furthermore, invasion and migration were significantly increased in the MDA-MB-231DAP3kd cells vs. the controls. The expression of caspase 9 and IPS1, known components of the apoptosis pathway, were significantly reduced in the MCF7DAP3kd cells (p=0.05 and p=0.003, respectively). We conclude that DAP3 silencing contributes to breast carcinogenesis by increasing cell adhesion, migration and invasion. It is possible that this may be due to the activity of focal adhesion kinase further downstream of the anoikis pathway. Further research in this direction would be beneficial in increasing our understanding of the mechanisms underlying human breast cancer. PMID:25738636

  15. Decreased sickle red blood cell adhesion to laminin by hydroxyurea is associated with inhibition of Lu/BCAM protein phosphorylation

    E-print Network

    Paris-Sud XI, Université de

    1 Decreased sickle red blood cell adhesion to laminin by hydroxyurea is associated with inhibition, published in "Blood 2010;116(12):2152-9" DOI : 10.1182/blood-2009-12-257444 #12;2 Abstract Sickle-cell, the only drug with proven benefit in sickle-cell disease, diminishes these interactions but its mechanism

  16. A Lipid Transfer-like Protein Is Necessary for Lily Pollen Tube Adhesion to an in Vitro Stylar Matrix

    Microsoft Academic Search

    Sang-Youl Park; Guang-Yuh Jauh; Jean-Claude Mollet; Kathleen J. Eckard; Eugene A. Nothnagel; Linda L. Walling; Elizabeth M. Lord

    2000-01-01

    Flowering plants possess specialized extracellular matrices in the female organs of the flower that support pollen tube growth and sperm cell transfer along the transmitting tract of the gynoecium. Transport of the pollen tube cell and the sperm cells involves a cell adhesion and migration event in species such as lily that possess a transmitting tract epider- mis in the

  17. Differential adhesion, activity, and carbohydrate: Protein ratios of Pseudomonas atlantica monocultures attaching to stainless steel in a linear shear gradient

    Microsoft Academic Search

    M. W. Mittelman; D. E. Nivens; C. Low; D. C. White

    1990-01-01

    Biofilm formation on metallic surfaces in marine and freshwater environments often precedes corrosion and other biofouling conditions. Attachment is mediated by such environmental factors as the presence of surface conditioning films, fluid dynamics, bulk-phase nutrient levels, and surface chemistry. In this study, we utilized a Fowler Cell Adhesion Measurement Module to demonstrate that the changes in cellular concentration and composition

  18. Cadherin-Dependent Cell Morphology in an Epithelium: Constructing a Quantitative Dynamical Model

    PubMed Central

    Gemp, Ian M.; Carthew, Richard W.; Hilgenfeldt, Sascha

    2011-01-01

    Cells in the Drosophila retina have well-defined morphologies that are attained during tissue morphogenesis. We present a computer simulation of the epithelial tissue in which the global interfacial energy between cells is minimized. Experimental data for both normal cells and mutant cells either lacking or misexpressing the adhesion protein N-cadherin can be explained by a simple model incorporating salient features of morphogenesis that include the timing of N-cadherin expression in cells and its temporal relationship to the remodeling of cell-cell contacts. The simulations reproduce the geometries of wild-type and mutant cells, distinguish features of cadherin dynamics, and emphasize the importance of adhesion protein biogenesis and its timing with respect to cell remodeling. The simulations also indicate that N-cadherin protein is recycled from inactive interfaces to active interfaces, thereby modulating adhesion strengths between cells. PMID:21814505

  19. The Src Homology 3 Domain Is Required for Junctional Adhesion Molecule Binding to the Third PDZ Domain of the Scaffolding Protein ZO-1

    SciTech Connect

    Nomme, Julian; Fanning, Alan S.; Caffrey, Michael; Lye, Ming F.; Anderson, James M.; Lavie, Arnon (NIH); (UNC); (UIC)

    2012-01-20

    Tight junctions are cell-cell contacts that regulate the paracellular flux of solutes and prevent pathogen entry across cell layers. The assembly and permeability of this barrier are dependent on the zonula occludens (ZO) membrane-associated guanylate kinase (MAGUK) proteins ZO-1, -2, and -3. MAGUK proteins are characterized by a core motif of protein-binding domains that include a PDZ domain, a Src homology 3 (SH3) domain, and a region of homology to guanylate kinase (GUK); the structure of this core motif has never been determined for any MAGUK. To better understand how ZO proteins organize the assembly of protein complexes we have crystallized the entire PDZ3-SH3-GUK core motif of ZO-1. We have also crystallized this core motif in complex with the cytoplasmic tail of the ZO-1 PDZ3 ligand, junctional adhesion molecule A (JAM-A) to determine how the activity of different domains is coordinated. Our study shows a new feature for PDZ class II ligand binding that implicates the two highly conserved Phe{sup -2} and Ser{sup -3} residues of JAM. Our x-ray structures and NMR experiments also show for the first time a role for adjacent domains in the binding of ligands to PDZ domains in the MAGUK proteins family.

  20. A cytoplasmic protein, bystin, interacts with trophinin, tastin, and cytokeratin and may be involved in trophinin-mediated cell adhesion between trophoblast and endometrial epithelial cells

    PubMed Central

    Suzuki, Nao; Zara, Jane; Sato, Takaaki; Ong, Edgar; Bakhiet, Nouna; Oshima, Robert G.; Watson, Kellie L.; Fukuda, Michiko N.

    1998-01-01

    Trophinin and tastin form a cell adhesion molecule complex that potentially mediates an initial attachment of the blastocyst to uterine epithelial cells at the time of implantation. Trophinin and tastin, however, do not directly bind to each other, suggesting the presence of an intermediary protein. The present study identifies a cytoplasmic protein, named bystin, that directly binds trophinin and tastin. Bystin consists of 306 amino acid residues and is predicted to contain tyrosine, serine, and threonine residues in contexts conforming to motifs for phosphorylation by protein kinases. Database searches revealed a 53% identity of the predicted peptide sequence with the Drosophila bys (mrr) gene. Direct protein–protein interactions of trophinin, tastin, and bystin analyzed by yeast two-hybrid assays and by in vitro protein binding assays indicated that binding between bystin and trophinin and between bystin and tastin is enhanced when cytokeratin 8 and 18 are present as the third molecule. Immunocytochemistry of bystin showed that bystin colocalizes with trophinin, tastin, and cytokeratins in a human trophoblastic teratocarcinoma cell, HT-H. It is therefore possible that these molecules form a complex and thus are involved in the process of embryo implantation. PMID:9560222

  1. ?2-Macroglobulin Can Crosslink Multiple Plasmodium falciparum Erythrocyte Membrane Protein 1 (PfEMP1) Molecules and May Facilitate Adhesion of Parasitized Erythrocytes

    PubMed Central

    Stevenson, Liz; Laursen, Erik; Cowan, Graeme J.; Bandoh, Betty; Barfod, Lea; Cavanagh, David R.; Andersen, Gregers R.; Hviid, Lars

    2015-01-01

    Rosetting, the adhesion of Plasmodium falciparum-infected erythrocytes to uninfected erythrocytes, involves clonal variants of the parasite protein P. falciparum erythrocyte membrane protein 1 (PfEMP1) and soluble serum factors. While rosetting is a well-known phenotypic marker of parasites associated with severe malaria, the reason for this association remains unclear, as do the molecular details of the interaction between the infected erythrocyte (IE) and the adhering erythrocytes. Here, we identify for the first time a single serum factor, the abundant serum protease inhibitor ?2-macroglobulin (?2M), which is both required and sufficient for rosetting mediated by the PfEMP1 protein HB3VAR06 and some other rosette-mediating PfEMP1 proteins. We map the ?2M binding site to the C terminal end of HB3VAR06, and demonstrate that ?2M can bind at least four HB3VAR06 proteins, plausibly augmenting their combined avidity for host receptors. IgM has previously been identified as a rosette-facilitating soluble factor that acts in a similar way, but it cannot induce rosetting on its own. This is in contrast to ?2M and probably due to the more limited cross-linking potential of IgM. Nevertheless, we show that IgM works synergistically with ?2M and markedly lowers the concentration of ?2M required for rosetting. Finally, HB3VAR06+ IEs share the capacity to bind ?2M with subsets of genotypically distinct P. falciparum isolates forming rosettes in vitro and of patient parasite isolates ex vivo. Together, our results are evidence that P. falciparum parasites exploit ?2M (and IgM) to expand the repertoire of host receptors available for PfEMP1-mediated IE adhesion, such as the erythrocyte carbohydrate moieties that lead to formation of rosettes. It is likely that this mechanism also affects IE adhesion to receptors on vascular endothelium. The study opens opportunities for broad-ranging immunological interventions targeting the ?2M—(and IgM-) binding domains of PfEMP1, which would be independent of the host receptor specificity of clinically important PfEMP1 antigens. PMID:26134405

  2. Recombinant human interferon-inducible protein 10 is a chemoattractant for human monocytes and T lymphocytes and promotes T cell adhesion to endothelial cells

    PubMed Central

    1993-01-01

    The human cytokine interferon-inducible protein 10 (IP-10) is a small glycoprotein secreted by activated T cells, monocytes, endothelial cells, and keratinocytes, and is structurally related to a family of chemotactic cytokines called chemokines. Although this protein is present in sites of delayed-type hypersensitivity reactions and lepromatous leprosy lesions, the biological activity of IP-10 remains unknown. We report here that recombinant human IP-10 stimulated significant in vitro chemotaxis of human peripheral blood monocytes but not neutrophils. Recombinant human IP-10 also stimulated chemotaxis of stimulated, but not unstimulated, human peripheral blood T lymphocytes. Phenotypic analysis of the stimulated T cell population responsive to IP-10 demonstrated that stimulated CD4+ and CD29+ T cells migrated in response to IP-10. This resembles the biological activity of the previously described T cell chemoattractant RANTES. Using an endothelial cell adhesion assay, we demonstrated that stimulated T cells pretreated with optimal doses of IP-10 exhibited a greatly enhanced ability to bind to an interleukin 1-treated endothelial cell monolayer. These results demonstrate that the IP-10 gene encodes for an inflammatory mediator that specifically stimulates the directional migration of T cells and monocytes as well as potentiates T cell adhesion to endothelium. PMID:8496693

  3. Cell adhesion as a novel approach to determining the cellular binding motif on the severe acute respiratory syndrome coronavirus spike protein.

    PubMed

    Chang, Hsin-Hou; Chen, Po-Kong; Lin, Guan-Ling; Wang, Chun-Jen; Liao, Chih-Hsien; Hsiao, Yu-Cheng; Dong, Jing-Hua; Sun, Der-Shan

    2014-06-01

    Emerging life threatening pathogens such as severe acute aspiratory syndrome-coronavirus (SARS-CoV), avian-origin influenzas H7N9, and the Middle East respiratory syndrome coronavirus (MERS-CoV) have caused a high case-fatality rate and psychological effects on society and the economy. Therefore, a simple, rapid, and safe method to investigate a therapeutic approach against these pathogens is required. In this study, a simple, quick, and safe cell adhesion inhibition assay was developed to determine the potential cellular binding site on the SARS-CoV spike protein. Various synthetic peptides covering the potential binding site helped to minimize further the binding motif to 10-25 residues. Following analyses, 2 peptides spanning the 436-445 and 437-461 amino acids of the spike protein were identified as peptide inhibitor or peptide vaccine candidates against SARS-CoV. PMID:24530430

  4. Adhesive capsulitis.

    PubMed

    Tasto, James P; Elias, David W

    2007-12-01

    Adhesive capsulitis is a common problem seen in the general population by orthopedic surgeons. It is a problem that causes patients pain and disability, and symptoms can last up to 2 years and longer. The questions of when and how to treat the frozen shoulder can present challenges. Most treatments are conservative; however, indications for surgery do exist. Arthroscopic capsular release has gained popularity over the years and offers a predictably good treatment in patients with adhesive capsulitis. The purpose of this paper is to review the orthopedic literature on adhesive capsulitis, to provide background information on this topic, and to describe our technique in arthroscopic capsular release. PMID:18004221

  5. CPNA-1, a copine domain protein, is located at integrin adhesion sites and is required for myofilament stability in Caenorhabditis elegans

    PubMed Central

    Warner, Adam; Xiong, Ge; Qadota, Hiroshi; Rogalski, Teresa; Vogl, A. Wayne; Moerman, Donald G.; Benian, Guy M.

    2013-01-01

    We identify cpna-1 (F31D5.3) as a novel essential muscle gene in the nematode Caenorhabditis elegans. Antibodies specific to copine domain protein atypical-1 (CPNA-1), as well as a yellow fluorescent protein translational fusion, are localized to integrin attachment sites (M-lines and dense bodies) in the body-wall muscle of C. elegans. CPNA-1 contains an N-terminal predicted transmembrane domain and a C-terminal copine domain and binds to the M-line/dense body protein PAT-6 (actopaxin) and the M-line proteins UNC-89 (obscurin), LIM-9 (FHL), SCPL-1 (SCP), and UNC-96. Proper CPNA-1 localization is dependent upon PAT-6 in embryonic and adult muscle. Nematodes lacking cpna-1 arrest elongation at the twofold stage of embryogenesis and display disruption of the myofilament lattice. The thick-filament component myosin heavy chain MYO-3 and the M-line component UNC-89 are initially localized properly in cpna-1–null embryos. However, in these embryos, when contraction begins, MYO-3 and UNC-89 become mislocalized into large foci and animals die. We propose that CPNA-1 acts as a linker between an integrin-associated protein, PAT-6, and membrane-distal components of integrin adhesion complexes in the muscle of C. elegans. PMID:23283987

  6. Participation of heparin binding proteins from the surface of Leishmania (Viannia) braziliensis promastigotes in the adhesion of parasites to Lutzomyia longipalpis cells (Lulo) in vitro

    PubMed Central

    2012-01-01

    Background Leishmania (V.) braziliensis is a causative agent of cutaneous leishmaniasis in Brazil. During the parasite life cycle, the promastigotes adhere to the gut of sandflies, to avoid being eliminated with the dejection. The Lulo cell line, derived from Lutzomyia longipalpis (Diptera: Psychodidae), is a suitable in vitro study model to understand the features of parasite adhesion. Here, we analyze the role of glycosaminoglycans (GAGs) from Lulo cells and proteins from the parasites in this event. Methods Flagellar (Ff) and membrane (Mf) fractions from promastigotes were obtained by differential centrifugation and the purity of fractions confirmed by western blot assays, using specific antibodies for cellular compartments. Heparin-binding proteins (HBP) were isolated from both fractions using a HiTrap-Heparin column. In addition, binding of promastigotes to Lulo cells or to a heparin-coated surface was assessed by inhibition assays or surface plasmon resonance (SPR) analysis. Results The success of promastigotes subcellular fractionation led to the obtainment of Ff and Mf proteins, both of which presented two main protein bands (65.0 and 55.0kDa) with affinity to heparin. The contribution of HBPs in the adherence of promastigotes to Lulo cells was assessed through competition assays, using HS or the purified HBPs fractions. All tested samples presented a measurable inhibition rate when compared to control adhesion rate (17?±?2.0% of culture cells with adhered parasites): 30% (for HS 20?g/ml) and 16% (for HS 10?g/ml); HBP Mf (35.2% for 10?g/ml and 25.4% for 20?g/ml) and HBP Ff (10.0% for 10?g/ml and 31.4% for 20?g/ml). Additionally, to verify the presence of sulfated GAGs in Lulo cells surface and intracellular compartment, metabolic labeling with radioactive sulfate was performed, indicating the presence of an HS and chondroitin sulfate in both cell sections. The SPR analysis performed further confirmed the presence of GAGs ligands on L. (V.) braziliensis promastigote surfaces. Conclusions The data presented here point to evidences that HBPs present on the surface of L. (V.) braziliensis promastigotes participate in adhesion of these parasites to Lulo cells through HS participation. PMID:22805335

  7. Abdominal Adhesions

    MedlinePLUS

    ... abdominal tissues and organs. [ Top ] What is the abdominal cavity? The abdominal cavity is the internal area of the body between ... develop abdominal adhesions. 1 Surgery in the lower abdomen and pelvis, including bowel and gynecological operations, carries ...

  8. Expression of cell adhesion molecules in canine choroid plexus tumors

    PubMed Central

    HIROSE, Naoki; UCHIDA, Kazuyuki; MATSUNAGA, Satoru; CHAMBERS, James Kenn; NAKAYAMA, Hiroyuki

    2014-01-01

    Choroid plexus tumor (CPT) is a primary intracranial neoplasm of the choroid plexus epithelium in the central nervous system. In the current World Health Organization classification, CPT is classified into two categories; choroid plexus papilloma (CPP) and carcinoma (CPC). In the present study, we investigated immunohistochemical expressions of N-cadherin, E-cadherin and ?-catenin in 5 canine CPT cases (1 disseminated CPC, 2 CPCs and 2 CPPs). One CPP case was positive for N-cadherin and ?-catenin, but negative for E-cadherin. The disseminated CPC case was positive for E-cadherin and ?-catenin, but negative for N-cadherin. The other cases were positive for the three molecules examined. These results suggest that loss of the N-cadherin expression might associate with the spreading of CPC cells. PMID:25373880

  9. Evidence for in vivo phosphorylation of the Grb2 SH2-domain binding site on focal adhesion kinase by Src-family protein-tyrosine kinases.

    PubMed Central

    Schlaepfer, D D; Hunter, T

    1996-01-01

    Focal adhesion kinase (FAK) is a nonreceptor protein-tyrosine kinase (PTK) that associates with integrin receptors and participates in extracellular matrix-mediated signal transduction events. We showed previously that the c-Src nonreceptor PTK and the Grb2 SH2/SH3 adaptor protein bound directly to FAK after fibronectin stimulation (D. D. Schlaepfer, S.K. Hanks, T. Hunter, and P. van der Geer, Nature [London] 372:786-791, 1994). Here, we present evidence that c-Src association with FAK is required for Grb2 binding to FAK. Using a tryptic phosphopeptide mapping approach, the in vivo phosphorylation of the Grb2 binding site on FAK (Tyr-925) was detected after fibronectin stimulation of NIH 3T3 cells and was constitutively phosphorylated in v-Src-transformed NIH 3T3 cells. In vitro, c-Src phosphorylated FAK Tyr-925 in a glutathione S-transferase-FAK C-terminal domain fusion protein, whereas FAK did not. Using epitope-tagged FAK constructs, transiently expressed in human 293 cells, we determined the effect of site-directed mutations on c-Src and Grb2 binding to FAK. Mutation of FAK Tyr-925 disrupted Grb2 binding, whereas mutation of the c-Src binding site on FAK (Tyr-397) disrupted both c-Src and Grb2 binding to FAK in vivo. These results support a model whereby Src-family PTKs are recruited to FAK and focal adhesions following integrin-induced autophosphorylation and exposure of FAK Tyr-397. Src-family binding and phosphorylation of FAK at Tyr-925 creates a Grb2 SH2-domain binding site and provides a link to the activation of the Ras signal transduction pathway. In Src-transformed cells, this pathway may be constitutively activated as a result of FAK Tyr-925 phosphorylation in the absence of integrin stimulation. PMID:8816475

  10. Effect of the knockdown of death-associated protein 1 expression on cell adhesion, growth and migration in breast cancer cells.

    PubMed

    Wazir, Umar; Sanders, Andrew J; Wazir, Ali; Baig, Ruqia Mehmood; Jiang, Wen G; Ster, Irina C; Sharma, Anup K; Mokbel, Kefah

    2015-03-01

    Death-associated protein 1 (DAP1) is a highly conserved phosphoprotein involved in the regulation of autophagy. A previous clinical study by our group suggested an association between low DAP1 expression and clinicopathological parameters of human breast cancer. In the present study, we aimed to determine the role of DAP1 in cancer cell behaviour in the context of human breast cancer. We developed knockdown sublines of MCF7 and MDA-MB?231, and performed growth, adhesion and invasion assays and electric cell-substrate impedance sensing (ECIS) studies of the post-wound migration of cells. In addition, we studied the mRNA expression of caspase 8 and 9, DELE, IPS1, cyclin D1 and p21 in the control and knockdown sublines. Knockdown was associated with increased adhesion and migration, significantly so in the MDA-MB-231DAP1kd cell subline (p=0.029 and p=0.001, respectively). Growth in MCF7 cells showed a significant suppression on day 3 (p=0.029), followed by an increase in growth matching the controls on day 5. While no change in the apoptotic response to serum starvation could be attributed to DAP1 knockdown, the expression of known components of the apoptosis pathway (caspase 8) and cell cycle (p21) was significantly reduced in the MCF7DAP1kd cell subline (p?0.05), while in MDA-MB-231DAP1kd the expression of a pro-apoptotic molecule, IPS1, was suppressed (p?0.05). DAP1 may have an important role in cell adhesion, migration and growth in the context of breast cancer and has significant associations with the apoptosis pathway. Furthermore, we believe that delayed increase in growth observed in the MCF7DAP1kd cell subline may indicate activation of a strongly pro-oncogenic pathway downstream of DAP1. PMID:25530065

  11. A dual role for Sonic hedgehog in regulating adhesion and differentiation of neuroepithelial cells.

    PubMed

    Jarov, Artem; Williams, Kevin P; Ling, Leona E; Koteliansky, Victor E; Duband, Jean-Loup; Fournier-Thibault, Claire

    2003-09-15

    In vertebrates, the nervous system arises from a flat sheet of epithelial cells, the neural plate, that gradually transforms into a hollow neural tube. This process, called neurulation, involves sequential changes in cellular interactions that are precisely coordinated both spatially and temporally by the combined actions of morphogens. To gain further insight into the molecular events regulating cell adhesion during neurulation, we investigated whether the adhesive and migratory capacities of neuroepithelial cells might be modulated by Sonic hedgehog (Shh), a signaling molecule involved in the control of cell differentiation in the ventral neural tube. When deposited onto extracellular matrix components in vitro, neural plates explanted from avian embryos at early neurulation readily dispersed into monolayers of spread cells, thereby revealing their intrinsic ability to migrate. In the presence of Shh added in solution to the culture medium, the explants still exhibited the same propensity to disperse. In contrast, when Shh was immobilized to the substrate or produced by neuroepithelial cells themselves after transfection, neural plate explants failed to disperse and instead formed compact structures. Changes in the adhesive capacities of neuroepithelial cells caused by Shh could be accounted for by inactivation of surface beta1-integrins combined with an increase in N-cadherin-mediated cell adhesion. Furthermore, immobilized Shh promoted differentiation of neuroepithelial cells into motor neurons and floor plate cells with the same potency as soluble Shh. However, the effect of Shh on the neuroepithelial cell adhesion was discernible and apparently independent from its differentiation effect and was not mediated by the signaling cascade elicited by the Patched-Smoothened receptor and involving the Gli transcription factors. Thus, our experiments indicate that Shh is able to control sequentially adhesion and differentiation of neuroepithelial cells through different mechanisms, leading to a coordinated regulation of the various cell interactions essential for neural tube morphogenesis. PMID:14499657

  12. G?s proteins activate p72(Syk) and p60-c-Src tyrosine kinases to mediate sickle red blood cell adhesion to endothelium via LW-?v?3 and CD44-CD44 interactions.

    PubMed

    Chiou, Edward; Zennadi, Rahima

    2015-08-01

    G protein-coupled receptors (GPCRs) have been suggested as new drug targets to treat a variety of diseases. In sickle cell disease (SCD), the LW erythrocyte adhesion receptor can be activated by stimulation of ?2 adrenergic receptors (?2ARs), to mediate sickle erythrocyte (SSRBC) adhesion to endothelium. However, the involvement of tyrosine protein kinases in ?2AR signaling to activate SSRBC adhesion to endothelium has not been thoroughly elucidated. Either direct activation with Cholera toxin of G?s protein, which acts downstream of ?2ARs, or inhibition with Pertussis toxin of G?i, mediating suppression of adenylyl cyclase, increased SSRBC adhesion to endothelium over baseline adhesion. This effect involved the non-receptor tyrosine kinases, p72(Syk) and p60-c-Src, which were more abundant in SSRBCs than in normal erythrocytes. In contrast, Pertussis toxin and Cholera toxin failed to increase adhesion of normal erythrocytes. SSRBC G?i inhibition also increased phosphorylation of p72(Syk) and p60-c-Src. Further, we investigated the relevance of activation of p72(Syk) and p60-c-Src, and identified LW (ICAM-4, CD242) and CD44 as the erythroid adhesion molecules both physically interacting with activated p60-c-Src. As a result, SSRBC LW underwent increased tyrosine phosphorylation, leading to SSRBC LW and CD44 binding to endothelial ?v?3 integrin and CD44, respectively. These data provide in vitro mechanistic evidence that p60-c-Src, which could act downstream of G?s/p72(Syk), associates with LW and CD44 on SSRBCs leading to their interactions with endothelial ?v?3 and CD44, respectively. Thus, increased activation of these signaling mechanisms in SSRBCs could initiate or exacerbate vascular occlusion, the hallmark of SCD. PMID:26007235

  13. MUC16/CA125 in the Context of Modular Proteins with an Annotated Role in Adhesion-Related Processes: In Silico Analysis

    PubMed Central

    Jankovic, Miroslava; Mitic, Ninoslav

    2012-01-01

    Mucin 16 (MUC16) is a type I transmembrane protein, the extracellular portion of which is shed after proteolytic degradation and is denoted as CA125 antigen, a well known tumor marker for ovarian cancer. Regarding its polypeptide and glycan structures, as yet there is no detailed insight into their heterogeneity and ligand properties, which may greatly influence its function and biomarker potential. This study was aimed at obtaining further insight into the biological capacity of MUC16/CA125, using in silico analysis of corresponding mucin sequences, including similarity searches as well as GO (gene ontology)-based function prediction. The results obtained pointed to the similarities within extracellular serine/threonine rich regions of MUC16 to sequences of proteins expressed in evolutionary distant taxa, all having in common an annotated role in adhesion-related processes. Specifically, a homology to conserved domains from the family of herpesvirus major outer envelope protein (BLLF1) was found. In addition, the possible involvement of MUC16/CA125 in carbohydrate-binding interactions or cellular transport of protein/ion was suggested. PMID:22949868

  14. Artificial biomimicking matrix modifications of nanofibrous scaffolds by hE-cadherin-Fc fusion protein to promote human mesenchymal stem cells adhesion and proliferation.

    PubMed

    Xu, Jianbin; Li, Suhua; Hu, Feifei; Zhu, Chuanshun; Zhang, Yan; Zhao, Wei; Akaike, Toshihiro; Yang, Jun

    2014-06-01

    Extracellular matrix (ECM) plays a fundamental role in regulating cell attachment, proliferation, migration and differentiation. Both synthetic and biologically derived materials have been explored as an ECM in regenerative medicine and tissue engineering. To biomimick the extracellular matrix, we combined the advantages of the biological properties of nanofibrous scaffolds and the fusion protein to apply for the culture of human mesenchymal stem cells in vitro. In this study, we fabricated well random-oriented/aligned nanofibrous scaffolds with PCL, modified with hE-cadherin-Fc fusion protein and studied the synergistic effect of the scaffolds. The random-oriented/aligned architecture was observed in the nanofibrous scaffolds by SEM. XPS and WCA measurements evidenced that hE-cadherin-Fc was successfully modified on the PCL nanofibrous scaffolds and hydrophilicity of the scaffolds was well improved after fusion protein coating. The hE-cadherin-Fc modified markedly promoted the adhesion and proliferation of hMSCs and guided hMSCs to a spindlier morphology compared with unmodified nanofibrous scaffolds. Furthermore, hMSCs on the hE-cadherin-Fc-coated nanofibrous scaffolds also had differentiation potential. These results suggested that the combination of PCL nanofibrous scaffolds and hE-cadherin-Fc fusion protein may be a promising artificial ECM for the behavior of hMSCs in vitro. PMID:24738344

  15. NMR analysis of the fibronectin cell-adhesive sequence, Arg-Gly-Asp, in a recombinant silk-like protein and a model peptide.

    PubMed

    Asakura, Tetsuo; Nishi, Hirohito; Nagano, Aya; Yoshida, Ai; Nakazawa, Yasumoto; Kamiya, Masakatsu; Demura, Makoto

    2011-11-14

    It is well established that by introducing the cell-adhesive sequence Arg-Gly-Asp (RGD) from fibronectin into Bombyx mori silk fibroin by covalent coupling or bioengineering techniques, excellent biomaterials have been developed with the modified silk fibroin. However, there is no report about the structure and dynamics of the RGD moiety in the silk fibroin. To clarify the origin of such a high cell adhesion character and to design new recombinant silk protein with higher cell adhesion ability, it is necessary to characterize the structure and dynamics of the RGD moiety introduced into silk fibroin. In this study, the structure and dynamics of the RGD moiety in a recombinant silk-like protein, SLPF(10), consisting of the repeated silk fibroin sequence (AGSGAG)(3) and the sequence ASTGRGDSPA including the RGD moiety, were studied using solution NMR. The (1)H, (15)N, and (13)C chemical shifts indicate that the RGD moiety, as well as the silk fibroin sequence, takes a random coil form with high mobility in aqueous solution. Next, a (13)C solid-state NMR study was performed on a (13)C selectively labeled model peptide, AGSGAG[3-(13)C]A(7)GSGAGAGSGGT[2-(13)C]G(19)R[1-(13)C]G(21)DSPAGGGAGAGSGAG. After formic acid treatment, an increase in the ?-sheet fraction for the AGSGAG sequence and peak narrowing of the residues around the RGD moiety were observed in the dry state. The latter indicates a decrease in the chemical shift distribution although the RGD moiety is still in random coil. A decrease in the peak intensities of the RGD moiety in the swollen state after immersing it in distilled water was observed, indicating high mobility of the RGD sequence in the peptide in the swollen state. Thus, the random coil state of the RGD moiety in the recombinant silk-like protein is maintained in aqueous solution and also in both dry and swollen state. This is similar to the case of the RGD moiety in fibronectin. The presence of the linker ASTG at the N-terminus and SPAGG at the C-terminus seems important to maintain the random coil form and the flexible state of the RGD sequence in order to permit access for binding to various integrins. PMID:21955288

  16. Modulation of tight junction barrier function by outer membrane proteins of enteropathogenic Escherichia coli: role of F-actin and junctional adhesion molecule-1.

    PubMed

    Puthenedam, Manjula; Williams, Peter H; Lakshmi, B S; Balakrishnan, Arun

    2007-08-01

    Enteropathogenic Escherichia coli (EPEC) is a major cause of infantile diarrhea. In this work we investigated the effect of outer membrane proteins (OMP) of EPEC on barrier integrity and the role of actin, junctional adhesion molecule (JAM) and signaling pathways contributing to these changes. Barrier function was assessed by transepithelial electrical resistance (TER). OMP of wild type EPEC, eaeA and maltoporin mutants decreased TER levels of Caco-2 cells. The OMP of espB mutant was deficient in decreasing TER of Caco-2 cells. The proteinase K-digested wild type OMP and EAF mutant OMP did not cause any change in barrier function. Our previous studies have demonstrated that EPEC OMP induced changes in cadherin junctions of Caco-2 cells. Immunofluorescence revealed disruption in actin cytoskeleton by EPEC OMP. However, no change in expression of junctional adhesion molecule-1 was observed. NF-kappaB inhibitor slightly blocked the decrease in TER and protected against actin disruption while ERK1/2 inhibitor had no effect in blocking these changes. In conclusion, our data suggest that the OMP of EPEC alter intestinal barrier function by disrupting actin cytoskeleton and signaling pathways like NF-kappaB may have a role in regulating barrier changes. PMID:17382565

  17. Activin A and TGF-beta stimulate phosphorylation of focal adhesion proteins and cytoskeletal reorganization in rat aortic smooth muscle cells.

    PubMed

    Riedy, M C; Brown, M C; Molloy, C J; Turner, C E

    1999-08-25

    Activin A and Transforming Growth Factor-beta (TGF-beta) are members of a common family of cytokines that bind to and stimulate serine/threonine kinase receptors. Activin A and TGF-beta are important during embryonic development exerting both positive and negative effects on cell growth. In the adult organism, they function in processes such as tissue repair, cellular proliferation, and differentiation. Although activin A and TGF-beta often induce opposite functional outcomes in specific cells; proliferation or differentiation, both were found to stimulate the formation of actin stress fibers and focal adhesions in serum-starved rat aortic smooth muscle (RASM) cells. These structural changes were accompanied by phosphorylation of the focal adhesion proteins, paxillin, and p130(cas). Similar cytoskeletal and biochemical changes were observed with the vasoactive agonist angiotensin II. Activation of the ERK/MAP kinase pathway has been implicated in the migration in certain cell types. However, while activin A, TGF-beta, and angiotensin II all stimulated ERK activity in RASM cells, only activin A and angiotensin II stimulated migration. TGF-beta failed to illicit a chemotactic response. Furthermore, pharmacologic inhibition of MEK activity failed to block migration in response to activin A and angiotensin II, indicating RASM migration can occur independent of ERK activity. These results suggest that TGF-beta and activin A share several signaling pathways with angiotensin II leading to cytoskeletal remodeling and ERK activation, but there are distinct differences regarding the effect of these agonists on cellular migration. PMID:10438585

  18. The adaptor protein SAP directly associates with PECAM-1 and regulates PECAM-1-mediated-cell adhesion in T-like cell lines.

    PubMed

    Proust, Richard; Crouin, Catherine; Gandji, Leslie Yewakon; Bertoglio, Jacques; Gesbert, Franck

    2014-04-01

    SAP is a small cytosolic adaptor protein expressed in hematopoietic lineages whose main function is to regulate intracellular signaling pathways induced by the triggering of members of the SLAM receptor family. In this paper, we have identified the adhesion molecule PECAM-1 as a new partner for SAP in a conditional yeast two-hybrid screen. PECAM-1 is an immunoglobulin-like molecule expressed by endothelial cells and leukocytes, which possesses both pro- and anti-inflammatory properties. However, little is known about PECAM-1 functions in T cells. We show that SAP directly and specifically interacts with the cytosolic tyrosine 686 of PECAM-1. We generated different T-like cell lines in which SAP or PECAM-1 are expressed or down modulated and we demonstrate that a diminished SAP expression correlates with a diminished PECAM-1-mediated adhesion. Although SAP has mainly been shown to associate with SLAM receptors, we evidence here that SAP is a new actor downstream of PECAM-1. PMID:24388971

  19. The Orphan Adhesion G Protein-coupled Receptor GPR97 Regulates Migration of Lymphatic Endothelial Cells via the Small GTPases RhoA and Cdc42*

    PubMed Central

    Valtcheva, Nadejda; Primorac, Adriana; Jurisic, Giorgia; Hollmén, Maija; Detmar, Michael

    2013-01-01

    The important role of the lymphatic vascular system in pathological conditions such as inflammation and cancer has been increasingly recognized, but its potential as a pharmacological target is poorly exploited. Our study aimed at the identification and molecular characterization of lymphatic-specific G protein-coupled receptors (GPCRs) to assess new targets for pharmacological manipulation of the lymphatic vascular system. We used a TaqMan quantitative RT-PCR-based low density array to determine the GPCR expression profiles of ex vivo isolated intestinal mouse lymphatic (LECs) and blood vascular endothelial cells (BECs). GPR97, an orphan adhesion GPCR of unknown function, was the most highly and specifically expressed GPCR in mouse lymphatic endothelium. Using siRNA silencing, we found that GPR97-deficient primary human LECs displayed increased adhesion and collective cell migration, whereas single cell migration was decreased as compared with nontargeting siRNA-transfected control LECs. Loss of GPR97 shifted the ratio of active Cdc42 and RhoA and initiated cytoskeletal rearrangements, including F-actin redistribution, paxillin and PAK4 phosphorylation, and ?1-integrin activation. Our data suggest a possible role of GPR97 in lymphatic remodeling and furthermore provide the first insights into the biological functions of GPR97. PMID:24178298

  20. Rho-associated protein kinase inhibitor, Y-27632, significantly enhances cell adhesion and induces a delay in G1 to S phase transition in rabbit corneal endothelial cells.

    PubMed

    Diao, Yu-Mei; Hong, Jing

    2015-08-01

    Human corneal endothelial cells are a non-proliferative cell type. As a result of the increase in corneal endothelium disease, increasing numbers of studies have been conducted in order to promote corneal endothelial cell proliferation. The aim of the present study was to investigate the proliferative effects of Rho?associated protein kinase inhibitor, Y?27632, on rabbit corneal endothelial cells (rCECs). Y?27632 (1, 10 or 30 µM) was added at two different time points to two groups of rCECs. The first group received Y?27632 when rCECs were initially plated, and the second following 72 h of cell growth. Cell morphology and cell adhesion ratios were subsequently observed using light microscopy. A cell counting kit was used to measure the number of viable cells that adhered to culture plates. Cell cycle transitions and levels of Annexin V?positive apoptotic cells were detected using flow cytometry. Cells treated with 1 µM Y?27632 and 10 µM Y?27632 retained their cell shape. At a concentration of 30 µM Y?27632, the cell shape became irregular. Cell adhesion ratios, in 1 µM Y?27632 (36.84%), 10 µM Y?27632 (84.21%) and 30 µM Y?27632 (84.21%) were higher than the adhesion ratio in the control group (P<0.01). The optical densities of rCECs treated with 10 µM or 30 µM Y?27632 following 72 h of cell growth was less than that of the control cells (P<0.01), but higher than that of cells which received Y?27632 at the time of plating (P<0.01). Flow cytometry results also demonstrated that there was a delay in G1 to S phase cell cycle progression in rCECs following administration of 10 µM Y?27632 (P<0.01). Cell apoptosis was inhibited when 10 µM Y?27632 was added, at the time of cell plating, as well as when added following 72 h of cell growth (P<0.01). At a concentration of 10 µM Y?27632, there was an improvement in cell adhesion and an inhibition of the cell cycle in rabbit corneal endothelial cells. In conclusion, Y?27632 has different effects on rCECs when administered at varying concentrations and at particular stages of cell growth. PMID:25891854

  1. Synthesis and SAR study of new thiazole derivatives as vascular adhesion protein-1 (VAP-1) inhibitors for the treatment of diabetic macular edema.

    PubMed

    Inoue, Takayuki; Morita, Masataka; Tojo, Takashi; Yoshihara, Kousei; Nagashima, Akira; Moritomo, Ayako; Ohkubo, Mitsuru; Miyake, Hiroshi

    2013-03-01

    Vascular adhesion protein-1 (VAP-1), an amine oxidase that is also known as a semicarbazide-sensitive amine oxidase (SSAO), is present in particularly high levels in human plasma, and is considered a potential therapeutic target for various inflammatory diseases, including diabetes complications such as macular edema. In our VAP-1 inhibitor program, structural modifications following high-throughput screening (HTS) of our compound library resulted in the discovery that thiazole derivative 10, which includes a guanidine group, shows potent human VAP-1 inhibitory activity (IC(50) of 230 nM; rat IC(50) of 14 nM). Moreover, compound 10 exhibited significant inhibitory effects on ocular permeability in STZ-induced diabetic rats. PMID:23337801

  2. Novel hydrazine molecules as tools to understand the flexibility of vascular adhesion protein-1 ligand-binding site: toward more selective inhibitors.

    PubMed

    Nurminen, Elisa M; Pihlavisto, Marjo; Lázár, László; Pentikäinen, Ulla; Fülöp, Ferenc; Pentikäinen, Olli T

    2011-04-14

    Vascular adhesion protein-1 (VAP-1) belongs to a family of amine oxidases. It plays a role in leukocyte trafficking and in amine compound metabolism. VAP-1 is linked to various diseases, such as Alzheimer's disease, psoriasis, depression, diabetes, and obesity. Accordingly, selective inhibitors of VAP-1 could potentially be used to treat those diseases. In this study, eight novel VAP-1 hydrazine derivatives were synthesized and their VAP-1 and monoamine oxidase (MAO) inhibition ability was determined in vitro. MD simulations of VAP-1 with these new molecules reveal that the VAP-1 ligand-binding pocket is flexible and capable of fitting substantially larger ligands than was previously believed. The increase in the size of the VAP-1 ligands, together with the methylation of the secondary nitrogen atom of the hydrazine moiety, improves the VAP-1 selectivity over MAO. PMID:21405023

  3. Protein production, crystallization and preliminary crystallographic analysis of the four N-terminal immunoglobulin domains of Down syndrome cell adhesion molecule 1.

    PubMed

    Cheng, Linna; Li, Shu Ang; Yu, Yamei; Chen, Qiang

    2015-06-01

    Down syndrome cell adhesion molecule 1 (Dscam1), a member of the immunoglobulin (Ig) superfamily, plays important roles in both the nervous and the immune systems. Via alternative RNA splicing, Drosophila Dscam1 encodes a vast family of Ig-containing proteins that exhibit isoform-specific homophilic binding. Whether different Dscam1 isoforms adopt the same dimerization mode is under debate, and the detailed mechanism of Dscam1 specificity remains unclear. In this study, eight different isforms of Dscam1 Ig1-4 have been cloned, overexpressed, purified to homogeneity and crystallized. X-ray data were collected to 1.9-4.0?Å resolution. These structures will provide the opportunity to perform extensive structural comparisons of different Dscam1 isoforms and provide insight into its specificity. PMID:26057811

  4. Oxidative Stress Mediates CoCl 2 Induced Prostate Tumour Cell Adhesion: Role of Protein Kinase C and p38 Mitogen-Activated Protein Kinase

    Microsoft Academic Search

    Ning Lu; Hong Zhou; Yan-hua Lin; Zhi-qiang Chen; Yan Pan; Xue-jun Li

    2007-01-01

    Cobalt chloride (CoCl 2 ), an agent demonstrated to stabilize hypoxia-inducible factor-1, has been associated with various hypoxic responses, and recently, some reports have linked it to increasing tumour malignancy. In this study, we observed the alteration of cell adhesion after CoCl 2 treatment and analysed the potential mechanisms responsible for such adaptations in a prostate cancer cell line PC-3

  5. Cryptosporidium parvum:PCR-RFLP Analysis of the TRAP-C1 (Thrombospondin-Related Adhesive Protein of Cryptosporidium1) Gene Discriminates between Two Alleles Differentially Associated with Parasite Isolates of Animal and Human Origin

    Microsoft Academic Search

    Furio Spano; Lorenza Putignani; Serena Guida; Andrea Crisanti

    1998-01-01

    Spano, F., Putignani, L., Guida, S., Crisanti, A. 1998.Cryptosporidium parvum: PCR-RFLP analysis of the TRAP-C1 (thrombospondin-related adhesive protein ofCryptosporidium-1) gene discriminates between two alleles differentially associated with parasite isolates of animal and human origin.Experimental Parasitology90,195–198.

  6. West Nile virus infection modulates human brain microvascular endothelial cells tight junction proteins and cell adhesion molecules: Transmigration across the in vitro blood-brain barrier

    PubMed Central

    Verma, Saguna; Lo, Yeung; Chapagain, Moti; Lum, Stephanie; Kumar, Mukesh; Gurjav, Ulziijargal; Luo, Haiyan; Nakatsuka, Austin; Nerurkar, Vivek R.

    2009-01-01

    Neurological complications such as inflammation, failure of the blood-brain barrier (BBB), and neuronal death contribute to the mortality and morbidity associated with WNV-induced meningitis. Compromised BBB indicates the ability of the virus to gain entry into the CNS via the BBB, however, the underlying mechanisms, and the specific cell types associated with WNV-CNS trafficking are not well understood. Brain microvascular endothelial cells, main component of the BBB, represent a barrier to virus dissemination into the CNS and could play key role in WNV spread via hematogenous route. To investigate WNV entry into the CNS, we infected primary human brain microvascular endothelial (HBMVE) cells with the neurovirulent strain of WNV (NY99) and examined WNV replication kinetics together with the changes in the expressions of key tight junction proteins (TJP) and cell adhesion molecules (CAM). WNV infection of HBMVE cells was productive as analyzed by plaque assay and qRT-PCR, and did not induce cytopathic effect. Increased mRNA and protein expressions of TJP (claudin-1) and CAM (vascular cell adhesion molecule and E-selectin) were observed at days 2 and 3 after infection, respectively, which coincided with the peak in WNV replication. Further, using an in vitro BBB model comprised of HBMVE cells, we demonstrate that cell-free WNV can cross the BBB, without compromising the BBB integrity. These data suggest that infection of HBMVE cells can facilitate entry of cell-free virus into the CNS without disturbing the BBB, and increased CAM may assist in the trafficking of WNV-infected immune cells into the CNS, via ‘Trojan horse’ mechanism, thereby contributing to WNV dissemination in the CNS and associated pathology. PMID:19135695

  7. Silk fibroin protein from mulberry and non-mulberry silkworms: cytotoxicity, biocompatibility and kinetics of L929 murine fibroblast adhesion

    Microsoft Academic Search

    Chitrangada Acharya; Sudip K. Ghosh; S. C. Kundu

    2008-01-01

    Silks fibers and films fabricated from fibroin protein of domesticated mulberry silkworm cocoon have been traditionally utilized\\u000a as sutures in surgery and recently as biomaterial films respectively. Here, we explore the possibility of application of silk\\u000a fibroin protein from non-mulberry silkworm cocoon as a potential biomaterial aid. In terms of direct inflammatory potential,\\u000a fibroin proteins from Antheraea mylitta and Bombyx

  8. Polyimide adhesives

    NASA Technical Reports Server (NTRS)

    Progar, D. J.; Bell, V. L.; Saintclair, T. L. (inventors)

    1974-01-01

    A process of preparing aromatic polyamide-acids for use as adhesives is described. An equimolar quantity of an aromatic dianhydride is added to a stirred solution of an aromatic diamine in a water or alcohol-miscible ether solvent to obtain a viscous polymer solution. The polymeric-acid intermediate polymer does not become insoluble but directly forms a smooth viscous polymer solution. These polyamic-acid polymers are converted, by heating in the range of 200-300 C and with pressure, to form polyimides with excellent adhesive properties.

  9. Loss of Sertoli-germ cell adhesion determines the rapid germ cell elimination during the seasonal regression of the seminiferous epithelium of the large hairy armadillo Chaetophractus villosus.

    PubMed

    Luaces, Juan Pablo; Rossi, Luis Francisco; Sciurano, Roberta Beatriz; Rebuzzini, Paola; Merico, Valeria; Zuccotti, Maurizio; Merani, Maria Susana; Garagna, Silvia

    2014-03-01

    The armadillo Chaetophractus villosus is a seasonal breeder whose seminiferous epithelium undergoes rapid regression with massive germ cell loss, leaving the tubules with only Sertoli cells and spermatogonia. Here, we addressed the question of whether this regression entails 1) the disassembly of cell junctions (immunolocalization of nectin-3, Cadm1, N-cadherin, and beta-catenin, and transmission electron microscopy [TEM]); 2) apoptosis (immunolocalization of cytochrome c and caspase 3; TUNEL assay); and 3) the involvement of Sertoli cells in germ cell phagocytosis (TEM). We showed a dramatic reduction in the extension of vimentin filaments associated with desmosomelike junctions at the interface between Sertoli and germ cells, and an increased diffusion of the immunosignals of nectin-3, Cadm1, N-cadherin, and beta-catenin. Together, these results suggest loss of Sertoli-germ cell adhesion, which in turn might determine postmeiotic cell sloughing at the beginning of epithelium regression. Then, loss of Sertoli-germ cell adhesion triggers cell death. Cytochrome c is released from mitochondria, but although postmeiotic cells were negative for late apoptotic markers, at advanced regression spermatocytes were positive for all apoptotic markers. Transmission electron microscopy analysis showed cytoplasmic engulfment of cell debris and lipid droplets within Sertoli cells, a sign of their phagocytic activity, which contributes to the elimination of the residual meiocytes still present in the latest regression phases. These findings are novel and add new players to the mechanisms of seminiferous epithelium regression occurring in seasonal breeders, and they introduce the armadillo as an interesting model for studying seasonal spermatogenesis. PMID:24451984

  10. Vascular remodeling alters adhesion protein and cytoskeleton reactions to inflammatory stimuli resulting in enhanced permeability increases in rat venules

    PubMed Central

    Yuan, Dong

    2012-01-01

    Vascular remodeling has been implicated in many inflammation-involved diseases. This study aims to investigate the microvascular remodeling-associated alterations in cell-cell adhesion and cytoskeleton reactions to inflammatory stimuli and their impact on microvessel permeability. Experiments were conducted in individually perfused rat mesenteric venules. Microvessel permeability was determined by measuring hydraulic conductivity (Lp), and endothelial intracellular calcium concentration, [Ca2+]i, was measured in fura-2-perfused vessels. Alterations in VE-cadherin and F-actin arrangement were examined by confocal imaging. Vascular wall cellular composition and structural changes were evaluated by electron microscopy. Vessels exposed to platelet activating factor (PAF) on day 1 were reevaluated 3 days later in rats that had undergone survival surgery. Initial PAF exposure and surgical disturbance increased microvascular wall thickness along with perivascular cell proliferation and altered F-actin arrangement. Although basal permeability was not changed, upon reexposure to PAF, peak endothelial [Ca2+]i was augmented and the peak Lp was 9.3 ± 1.7 times higher than that of day 1. In contrast to patterns of PAF-induced stress fiber formation and VE-cadherin redistribution observed in day 1 vessels, the day 4 vessels at the potentiated Lp peak exhibited wide separations of VE-cadherin between endothelial cells and striking stress fibers throughout the vascular walls. Confocal images and ultrastructural micrographs also revealed that the largely separated VE-cadherin and endothelial gaps were completely covered by F-actin bundles in extended pericyte processes at the PAF-induced Lp peak. These results indicate that inflammation-induced vascular remodeling increased endothelial susceptibility to inflammatory stimuli with augmented Ca2+ response resulting in upregulated contractility and potentiated permeability increase. Weakened adhesions between the endothelial cells and contractile mechanisms are both involved in increasing permeability in the intact microvessels and are aggravated during remodeling. The perivascular cells play important roles in stabilizing the microvessel wall, while lessening an otherwise much greater magnitude of leakage during cytoskeletal contraction. PMID:22837164

  11. Production and characterization of a silk-like hybrid protein, based on the polyalanine region of Samia cynthia ricini silk fibroin and a cell adhesive region derived from fibronectin.

    PubMed

    Asakura, Tetsuo; Tanaka, Chikako; Yang, Mingying; Yao, Juming; Kurokawa, Masato

    2004-02-01

    There are a variety of silkworms and silk fibroins produced by them. Silks have many inherent suitable properties for biomaterials. In this paper, a novel silk-like hybrid protein, [DGG(A)(12)GGAASTGRGDSPAAS](5), which consists of polyalanine region of silk fibroin from a wild silkworm, Samia cynthia ricini, and cell adhesive region including Arg-Gly-Asp (RGD) sequence, derived from fibronectin, was designed and produced. The genes encoding the hybrid protein were constructed and expressed in Escherichia coli. The main conformation of the polyalanine region, that is, either alpha-helix or beta-sheet, could be easily controlled by treatment with different acidic solvents, trifluoroacetic acid or formic acid, respectively. This structural change was monitored with 13C CP/MAS NMR. Higher cell adhesive and growth activities of the hybrid protein compared with those of collagen were obtained. PMID:14607499

  12. Focal Adhesion Kinases in Adhesion Structures and Disease

    PubMed Central

    Eleniste, Pierre P.; Bruzzaniti, Angela

    2012-01-01

    Cell adhesion to the extracellular matrix (ECM) is essential for cell migration, proliferation, and embryonic development. Cells can contact the ECM through a wide range of matrix contact structures such as focal adhesions, podosomes, and invadopodia. Although they are different in structural design and basic function, they share common remodeling proteins such as integrins, talin, paxillin, and the tyrosine kinases FAK, Pyk2, and Src. In this paper, we compare and contrast the basic organization and role of focal adhesions, podosomes, and invadopodia in different cells. In addition, we discuss the role of the tyrosine kinases, FAK, Pyk2, and Src, which are critical for the function of the different adhesion structures. Finally, we discuss the essential role of these tyrosine kinases from the perspective of human diseases. PMID:22888421

  13. Exploring natural silk protein sericin for regenerative medicine: an injectable, photoluminescent, cell-adhesive 3D hydrogel

    NASA Astrophysics Data System (ADS)

    Wang, Zheng; Zhang, Yeshun; Zhang, Jinxiang; Huang, Lei; Liu, Jia; Li, Yongkui; Zhang, Guozheng; Kundu, Subhas C.; Wang, Lin

    2014-11-01

    Sericin, a major component of silk, has a long history of being discarded as a waste during silk processing. The value of sericin for tissue engineering is underestimated and its potential application in regenerative medicine has just begun to be explored. Here we report the successful fabrication and characterization of a covalently-crosslinked 3D pure sericin hydrogel for delivery of cells and drugs. This hydrogel is injectable, permitting its implantation through minimally invasive approaches. Notably, this hydrogel is found to exhibit photoluminescence, enabling bioimaging and in vivo tracking. Moreover, this hydrogel system possesses excellent cell-adhesive capability, effectively promoting cell attachment, proliferation and long-term survival of various types of cells. Further, the sericin hydrogel releases bioactive reagents in a sustained manner. Additionally, this hydrogel demonstrates good elasticity, high porosity, and pH-dependent degradation dynamics, which are advantageous for this sericin hydrogel to serve as a delivery vehicle for cells and therapeutic drugs. With all these unique features, it is expected that this sericin hydrogel will have wide utility in the areas of tissue engineering and regenerative medicine.

  14. Exploring natural silk protein sericin for regenerative medicine: an injectable, photoluminescent, cell-adhesive 3D hydrogel.

    PubMed

    Wang, Zheng; Zhang, Yeshun; Zhang, Jinxiang; Huang, Lei; Liu, Jia; Li, Yongkui; Zhang, Guozheng; Kundu, Subhas C; Wang, Lin

    2014-01-01

    Sericin, a major component of silk, has a long history of being discarded as a waste during silk processing. The value of sericin for tissue engineering is underestimated and its potential application in regenerative medicine has just begun to be explored. Here we report the successful fabrication and characterization of a covalently-crosslinked 3D pure sericin hydrogel for delivery of cells and drugs. This hydrogel is injectable, permitting its implantation through minimally invasive approaches. Notably, this hydrogel is found to exhibit photoluminescence, enabling bioimaging and in vivo tracking. Moreover, this hydrogel system possesses excellent cell-adhesive capability, effectively promoting cell attachment, proliferation and long-term survival of various types of cells. Further, the sericin hydrogel releases bioactive reagents in a sustained manner. Additionally, this hydrogel demonstrates good elasticity, high porosity, and pH-dependent degradation dynamics, which are advantageous for this sericin hydrogel to serve as a delivery vehicle for cells and therapeutic drugs. With all these unique features, it is expected that this sericin hydrogel will have wide utility in the areas of tissue engineering and regenerative medicine. PMID:25412301

  15. The conserved LIM domain-containing focal adhesion protein ZYX-1 regulates synapse maintenance in Caenorhabditis elegans.

    PubMed

    Luo, Shuo; Schaefer, Anneliese M; Dour, Scott; Nonet, Michael L

    2014-10-01

    We describe the identification of zyxin as a regulator of synapse maintenance in mechanosensory neurons in C. elegans. zyx-1 mutants lacked PLM mechanosensory synapses as adult animals. However, most PLM synapses initially formed during development but were subsequently lost as the animals developed. Vertebrate zyxin regulates cytoskeletal responses to mechanical stress in culture. Our work provides in vivo evidence in support of such a role for zyxin. In particular, zyx-1 mutant synaptogenesis phenotypes were suppressed by disrupting locomotion of the mutant animals, suggesting that zyx-1 protects mechanosensory synapses from locomotion-induced forces. In cultured cells, zyxin is recruited to focal adhesions and stress fibers via C-terminal LIM domains and modulates cytoskeletal organization via the N-terminal domain. The synapse-stabilizing activity was mediated by a short isoform of ZYX-1 containing only the LIM domains. Consistent with this notion, PLM synaptogenesis was independent of ?-actinin and ENA-VASP, both of which bind to the N-terminal domain of zyxin. Our results demonstrate that the LIM domain moiety of zyxin functions autonomously to mediate responses to mechanical stress and provide in vivo evidence for a role of zyxin in neuronal development. PMID:25252943

  16. Some fundamentals of adhesion in synthetic adhesives

    Microsoft Academic Search

    Cyprien Gay

    2003-01-01

    Various adhesion mechanisms that have been understood in the field of synthetic adhesives are described and these are linked with situations relevant to fouling issues. The review mainly deals with mechanical aspects of adhesion phenomena, with an emphasis on the role of the elasticity of the bodies, called substrata, attached by adhesive. The consequences of thin film geometry of the

  17. Biodegradable polymer adhesives, hybrids and nanomaterials

    Microsoft Academic Search

    Andreas Mylonakis

    2008-01-01

    Biodegradable polymeric products and organic-inorganic hybrid materials for a diversity of applications are the two main fields on which this research has been focused. A novel biodegradable adhesive, which mimics marine adhesive proteins, has been synthesized by the covalent incorporation of 3,4-dihydroxybenzoic acid onto the chitosan backbone. The adhesive strength of these materials varies with the molecular weight of the

  18. Cytomegalovirus Destruction of Focal Adhesions Revealed in a High-Throughput Western Blot Analysis of Cellular Protein Expression

    Microsoft Academic Search

    R. J. Stanton; B. P. McSharry; C. R. Rickards; E. C. Y. Wang; P. Tomasec; G. W. G. Wilkinson

    2007-01-01

    Human cytomegalovirus (HCMV) systematically manages the expression of cellular functions, rather than exerting the global shutoff of host cell protein synthesis commonly observed with other herpesviruses during the lytic cycle. While microarray technology has provided remarkable insights into viral control of the cellular transcriptome, HCMV is known to encode multiple mechanisms for posttranscriptional and posttranslation regulation of cellular gene expression.

  19. Structure and expression of the silk adhesive protein Ser2 in Bombyx mori Barbara Kludkiewicz a,b

    E-print Network

    ?urovec, Michal

    in revised form 27 November 2009 Accepted 30 November 2009 Keywords: Silkworm Sericin Cocoon Silk gland Repetitive sequence a b s t r a c t Sericins are soluble silk components encoded in Bombyx mori by three later in the last larval instar as the major sericins of cocoon silk. These proteins are, however

  20. Developing luminescent nanoprobes for labeling focal adhesion complex proteins and performing combined AFM-TIRF imaging of these conjugates 

    E-print Network

    Nathwani, Bhavik Bharat

    2008-10-10

    , are coated with a hydrophobic ligand. Therefore, they must be further processed to be soluble in water and made biocompatible. A process to coat the QDs with silk fibroin, a fibrous protein derived from the Bombyx mori silk worm, is described. Following...

  1. rMCP-2, the Major Rat Mucosal Mast Cell Protease, an Analysis of Its Extended Cleavage Specificity and Its Potential Role in Regulating Intestinal Permeability by the Cleavage of Cell Adhesion and Junction Proteins

    PubMed Central

    Fu, Zhirong; Thorpe, Michael; Hellman, Lars

    2015-01-01

    Mast cells of the rat intestinal mucosa express three chymotryptic enzymes named rMCP-2, -3 and 4. rMCP-2, the most abundant of these enzymes, has been shown to increase the permeability of the intestinal epithelium, most likely by cleavage of cell adhesion and junction proteins and thereby play a role in intestinal parasite clearance. However, no target for this effect has yet been identified. To address this question we here present its extended cleavage specificity. Phage display analysis showed that it is a chymase with a specificity similar to the corresponding enzyme in mice, mMCP-1, with a preference for Phe or Tyr in the P1 position, and a general preference for aliphatic amino acids both upstream and downstream of the cleavage site. The consensus sequence obtained from the phage display analysis was used to screen the rat proteome for potential targets. A few of the most interesting candidate substrates were cell adhesion and cell junction molecules. To see if these proteins were also susceptible to cleavage in their native conformation we cleaved 5 different recombinant cell adhesion and cell junction proteins. Three potential targets were identified: the loop 1 of occludin, protocadherin alpha 4 and cadherin 17, which indicated that these proteins were at least partly responsible for the previously observed prominent role of rMCP-2 in mucosal permeability and in parasite clearance. PMID:26114959

  2. Marine mussel adhesion: biochemistry, mechanisms, and biomimetics

    Microsoft Academic Search

    Nandika Bandara; Hongbo Zeng; Jianping Wu

    2012-01-01

    Common blue mussel (Mytilus edulis) is a sessile organism that has unique ability to attach to a wide array of organic and inorganic marine surfaces using its holdfast structures. Strong adhesion to surfaces is essential for mussel survival, movement, and self-defense. Mussel proteins from byssal thread are structural components connecting soft mussel tissues to marine surfaces via an adhesive plaque

  3. Animal Lectins as Cell Adhesion Molecules

    Microsoft Academic Search

    H. Kaltner; B. Stierstorfer

    1998-01-01

    Protein-carbohydrate interaction is exploited in cell adhesion mechanisms besides the recognition of peptide motifs. The sugar code thus significantly contributes to the intriguing specificity of cellular selection of binding partners. Focusing on two classes of lectins (selectins and galectins), it is evident that their functionality for mediation of adhesive contacts is becoming increasingly appreciated, as is the integration of this

  4. Developing luminescent nanoprobes for labeling focal adhesion complex proteins and performing combined AFM-TIRF imaging of these conjugates

    E-print Network

    Nathwani, Bhavik Bharat

    2008-10-10

    of semiconductor nanocrystals or Quantum Dots (QDs) has seen them find wider acceptance as a tool in biomedical research labs. As produced, high quality QDs synthesized by high temperature organometallic synthesis, are coated with a hydrophobic ligand.... Therefore, they must be further processed to be soluble in water and made biocompatible. A process to coat the QDs with silk fibroin, a fibrous protein derived from the Bombyx mori silk worm, is described. Following the coating process...

  5. Fps\\/Fes protein-tyrosine kinase regulates mast cell adhesion and migration downstream of Kit and ?1 integrin receptors

    Microsoft Academic Search

    Julie A. Smith; Lionel A. Samayawardhena; Andrew W. B. Craig

    2010-01-01

    Activation of Kit receptor protein-tyrosine kinase (PTK) by its ligand Stem Cell Factor (SCF) is required for the development of mast cells, and for the regulation of mast cell proliferation, migration and modulation of inflammatory mediator release. Recent studies have implicated the non-receptor PTK Fps\\/Fes (hereafter referred to as Fes) in signaling downstream of oncogenic Kit, however, the potential role

  6. Inhibition of sortase-mediated Staphylococcus aureus adhesion to fibronectin via fibronectin-binding protein by sortase inhibitors

    Microsoft Academic Search

    Ki-Bong Oh; Mi-Na Oh; Jae-Gyu Kim; Dong-Sun Shin; Jongheon Shin

    2006-01-01

    The sortase enzymes are a family of Gram-positive transpeptidases responsible for anchoring surface protein virulence factors\\u000a to the peptidoglycan cell wall layer. In Staphylococcus aureus, deletion of the sortase isoforms results in marked reduction in virulence and infection potential, making it an important\\u000a antivirulence target. Recombinant sortase A (SrtA) and sortase B (SrtB) were incubated with peptide substrate containing either

  7. Characterization of MspA, an Immunogenic Autotransporter Protein That Mediates Adhesion to Epithelial and Endothelial Cells in Neisseria meningitidis

    Microsoft Academic Search

    D. P. J. Turner; A. G. Marietou; L. Johnston; K. K. L. Ho; A. J. Rogers; K. G. Wooldridge; D. A. A. Ala'Aldeen

    2006-01-01

    A novel putative autotransporter protein (NMB1998) was identified in the available genomic sequence of meningococcal strain MC58 (ET-5; ST-32). The mspA gene is absent from the genomic sequences of menin- gococcal strain Z2491 (ET-IV; ST-4) and the gonococcal strain FA1090. An orthologue is present in the meningococcal strain FAM18 (ET-37; ST-11), but the sequence contains a premature stop codon, suggesting

  8. Controlled protein absorption and cell adhesion on polymer-brush-grafted poly(3,4-ethylenedioxythiophene) films.

    PubMed

    Zhao, Haichao; Zhu, Bo; Luo, Shyh-Chyang; Lin, Hsing-An; Nakao, Aiko; Yamashita, Yoshiro; Yu, Hsiao-hua

    2013-06-12

    Tailoring the surface of biometallic implants with protein-resistant polymer brushes represents an efficient approach to improve the biocompability and mechanical compliance with soft human tissues. A general approach utilizing electropolymerization to form initiating group (-Br) containing poly(3,4-ethylenedioxythiophen)s (poly(EDOT)s) is described. After the conducting polymer is deposited, neutral poly((oligo(ethylene glycol) methacrylate), poly(OEGMA), and zwitterionic poly([2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide), poly(SBMA), brushes are grafted by surface-initiated atom transfer radical polymerization. Quartz crystal microbalance (QCM) experiments confirm protein resistance of poly(OEGMA) and poly(SBMA)-grafted poly(EDOT)s. The protein binding properties of the surface are modulated by the density of polymer brushes, which is controlled by the feed content of initiator-containing monomer (EDOT-Br) in the monomer mixture solution for electropolymerization. Furthermore, these polymer-grafted poly(EDOT)s also prevent cells to adhere on the surface. PMID:23573953

  9. The Glycosylphosphatidyl Inositol-Anchored Adhesion Molecule F3/Contactin Is Required for Surface Transport of Paranodin/Contactin-Associated Protein (Caspr)

    PubMed Central

    Faivre-Sarrailh, Catherine; Gauthier, France; Denisenko-Nehrbass, Natalia; Le Bivic, André; Rougon, Geneviève; Girault, Jean-Antoine

    2000-01-01

    Paranodin/contactin-associated protein (caspr) is a transmembrane glycoprotein of the neurexin superfamily that is highly enriched in the paranodal regions of myelinated axons. We have investigated the role of its association with F3/contactin, a glycosylphosphatidyl inositol (GPI)-anchored neuronal adhesion molecule of the Ig superfamily. Paranodin was not expressed at the cell surface when transfected alone in CHO or neuroblastoma cells. Cotransfection with F3 resulted in plasma membrane delivery of paranodin, as analyzed by confocal microscopy and cell surface biotinylation. The region that mediates association with paranodin was mapped to the Ig domains of F3 by coimmunoprecipitation experiments. The association of paranodin with F3 allowed its recruitment to Triton X-100–insoluble microdomains. The GPI anchor of F3 was necessary, but not sufficient for surface expression of paranodin. F3-Ig, a form of F3 deleted of the fibronectin type III (FNIII) repeats, although GPI-linked and expressed at the cell surface, was not recovered in the microdomain fraction and was unable to promote cell surface targeting of paranodin. Thus, a cooperative effect between the GPI anchor, the FNIII repeats, and the Ig regions of F3 is required for recruitment of paranodin into lipid rafts and its sorting to the plasma membrane. PMID:10769038

  10. Production and characterization of a silk-like hybrid protein, based on the polyalanine region of Samia cynthia ricini silk fibroin and a cell adhesive region derived from fibronectin

    Microsoft Academic Search

    Tetsuo Asakura; Chikako Tanaka; Mingying Yang; Juming Yao; Masato Kurokawa

    2004-01-01

    There are a variety of silkworms and silk fibroins produced by them. Silks have many inherent suitable properties for biomaterials. In this paper, a novel silk-like hybrid protein, [DGG(A)12GGAASTGRGDSPAAS]5, which consists of polyalanine region of silk fibroin from a wild silkworm, Samia cynthia ricini, and cell adhesive region including Arg-Gly-Asp (RGD) sequence, derived from fibronectin, was designed and produced. The

  11. Reduction of lung metastasis, cell invasion, and adhesion in mouse melanoma by statin-induced blockade of the Rho/Rho-associated coiled-coil-containing protein kinase pathway

    PubMed Central

    2010-01-01

    Background Melanomas are highly malignant and have high metastatic potential; hence, there is a need for new therapeutic strategies to prevent cell metastasis. In the present study, we investigated whether statins inhibit tumor cell migration, invasion, adhesion, and metastasis in the B16BL6 mouse melanoma cell line. Methods The cytotoxicity of statins toward the B16BL6 cells were evaluated using a cell viability assay. As an experimental model, B16BL6 cells were intravenously injected into C57BL/6 mice. Cell migration and invasion were assessed using Boyden chamber assays. Cell adhesion analysis was performed using type I collagen-, type IV collagen-, fibronectin-, and laminin-coated plates. The mRNA levels, enzyme activities and protein levels of matrix metalloproteinases (MMPs) were determined using RT-PCR, activity assay kits, and Western blot analysis, respectively; the mRNA and protein levels of vary late antigens (VLAs) were also determined. The effects of statins on signal transduction molecules were determined by western blot analyses. Results We found that statins significantly inhibited lung metastasis, cell migration, invasion, and adhesion at concentrations that did not have cytotoxic effects on B16BL6 cells. Statins also inhibited the mRNA expressions and enzymatic activities of matrix metalloproteinases (MMPs). Moreover, they suppressed the mRNA and protein expressions of integrin ?2, integrin ?4, and integrin ?5 and decreased the membrane localization of Rho, and phosphorylated LIM kinase (LIMK) and myosin light chain (MLC). Conclusions The results indicated that statins suppressed the Rho/Rho-associated coiled-coil-containing protein kinase (ROCK) pathways, thereby inhibiting B16BL6 cell migration, invasion, adhesion, and metastasis. Furthermore, they markedly inhibited clinically evident metastasis. Thus, these findings suggest that statins have potential clinical applications for the treatment of tumor cell metastasis. PMID:20843370

  12. Expression of P30, a protein with adhesive properties, in Schwann cells and neurons of the developing and regenerating peripheral nerve

    PubMed Central

    1991-01-01

    P30 is a heparin-binding protein with adhesive and neurite outgrowth- promoting properties present at high levels in the developing rat central nervous system (Rauvala, H., and R. Pihlaskari. 1987 J. Biol. Chem. 262:16625-16635). Partial sequencing of p30 has revealed homology or identity with HMG-1 (Rauvala, H., J. Merenmies, R. Pihlaskari, M. Korkolainen, M.-L. Huhtala, and P. Panula. 1988. J. Cell Biol. 107:2292- 2305), a 28-kD protein that was originally purified from the thymus (Goodwin, G.H., C. Sanders, and E. W. Johns. 1973. Eur. J. Biochem. 38:14-19) which binds DNA in vitro. We have analyzed the distribution of p30 in the developing rat peripheral nervous system (PNS). P30 was detected by immunohistochemistry and Western blot analysis using antibodies raised against intact p30 and against a synthetic peptide corresponding to the amino terminus of the p30 molecule. P30 was localized to nonnuclear compartments of neurons and peripheral glial cells (Schwann cells). P30 immunoreactivity of PNS neurons persisted into adulthood. In contrast, Schwann cell staining decreased after the second postnatal week and was not detectable in adult animals. Neuron- Schwann cell contact was correlated with diminished p30 levels in Schwann cells. Schwann cells of the normal adult sciatic nerve did not express p30; however, when deprived of axonal contact by nerve transection, the Schwann cells of the distal nerve stained intensely for p30. In addition, when Schwann cells and dorsal root ganglion neurons were grown in coculture, Schwann cells that were associated with neurites were not as intensely stained by anti-p30 as Schwann cells that were not in contact with neurons. The pattern of p30 expression during development and regeneration, and its apparent regulation by cell-cell contact suggests that p30 plays a role in the interaction between neurons and Schwann cells during morphogenesis of peripheral nerves. PMID:1999471

  13. Protein Kinase G and Focal Adhesion Kinase Converge on Src/Akt/?-Catenin Signaling Module in Osteoblast Mechanotransduction*

    PubMed Central

    Rangaswami, Hema; Schwappacher, Raphaela; Tran, Trish; Chan, Geraldine C.; Zhuang, Shunhui; Boss, Gerry R.; Pilz, Renate B.

    2012-01-01

    Mechanical loading of bone induces interstitial fluid flow, leading to fluid shear stress (FSS) of osteoblasts. FSS rapidly increases the intracellular calcium concentration ([Ca2+]) and nitric oxide (NO) synthesis in osteoblasts and activates the protein kinase Akt. Activated Akt stimulates osteoblast proliferation and survival, but the mechanism(s) leading to Akt activation is not well defined. Using pharmacological and genetic approaches in primary human and mouse osteoblasts and mouse MC3T3 osteoblast-like cells, we found that Akt activation by FSS occurred through two parallel pathways; one required calcium stimulation of NO synthase and NO/cGMP/protein kinase G II-dependent activation of Src, and the other required calcium activation of FAK and Src, independent of NO. Both pathways cooperated to increase PI3K-dependent Akt phosphorylation and were necessary for FSS to induce nuclear translocation of ?-catenin, c-fos, and cox-2 gene expression and osteoblast proliferation. These data explain how mechanical stimulation of osteoblasts leads to increased signaling through a growth regulatory pathway essential for maintaining skeletal integrity. PMID:22563076

  14. Exploiting the superior protein resistance of polymer brushes to control single cell adhesion and polarisation at the micron scale

    PubMed Central

    Gautrot, Julien E.; Trappmann, Britta; Oceguera-Yanez, Fabian; Connelly, John; He, Ximin; Watt, Fiona M.; Huck, Wilhelm T.S.

    2010-01-01

    The control of the cell microenvironment on model patterned substrates allows the systematic study of cell biology in well defined conditions, potentially using automated systems. The extreme protein resistance of poly(oligo(ethylene glycol methacrylate)) (POEGMA) brushes is exploited to achieve high fidelity patterning of single cells. These coatings can be patterned by soft lithography on large areas (a microscope slide) and scale (substrates were typically prepared in batches of 200). The present protocol relies on the adsorption of extra-cellular matrix (ECM) proteins on unprotected areas using simple incubation and washing steps. The stability of POEGMA brushes, as examined via ellipsometry and SPR, is found to be excellent, both during storage and cell culture. The impact of substrate treatment, brush thickness and incubation protocol on ECM deposition, both for ultra-thin gold and glass substrates, is investigated via fluorescence microscopy and AFM. Optimised conditions result in high quality ECM patterns at the micron scale, even on glass substrates, that are suitable for controlling cell spreading and polarisation. These patterns are compatible with state-of-the-art technologies (fluorescence microscopy, FRET) used for live cell imaging. This technology, combined with single cell analysis methods, provides a platform for exploring the mechanisms that regulate cell behaviour. PMID:20347135

  15. Mussel-Inspired Adhesives and Coatings

    PubMed Central

    Lee, Bruce P.; Messersmith, P.B.; Israelachvili, J.N.; Waite, J.H.

    2011-01-01

    Mussels attach to solid surfaces in the sea. Their adhesion must be rapid, strong, and tough, or else they will be dislodged and dashed to pieces by the next incoming wave. Given the dearth of synthetic adhesives for wet polar surfaces, much effort has been directed to characterizing and mimicking essential features of the adhesive chemistry practiced by mussels. Studies of these organisms have uncovered important adaptive strategies that help to circumvent the high dielectric and solvation properties of water that typically frustrate adhesion. In a chemical vein, the adhesive proteins of mussels are heavily decorated with Dopa, a catecholic functionality. Various synthetic polymers have been functionalized with catechols to provide diverse adhesive, sealant, coating, and anchoring properties, particularly for critical biomedical applications. PMID:22058660

  16. Control of vascular permeability by adhesion molecules.

    PubMed

    Sarelius, Ingrid H; Glading, Angela J

    2015-01-01

    Vascular permeability is a vital function of the circulatory system that is regulated in large part by the limited flux of solutes, water, and cells through the endothelial cell layer. One major pathway through this barrier is via the inter-endothelial junction, which is driven by the regulation of cadherin-based adhesions. The endothelium also forms attachments with surrounding proteins and cells via 2 classes of adhesion molecules, the integrins and IgCAMs. Integrins and IgCAMs propagate activation of multiple downstream signals that potentially impact cadherin adhesion. Here we discuss the known contributions of integrin and IgCAM signaling to the regulation of cadherin adhesion stability, endothelial barrier function, and vascular permeability. Emphasis is placed on known and prospective crosstalk signaling mechanisms between integrins, the IgCAMs- ICAM-1 and PECAM-1, and inter-endothelial cadherin adhesions, as potential strategic signaling nodes for multipartite regulation of cadherin adhesion. PMID:25838987

  17. Candida biofilms: is adhesion sexy?

    PubMed

    Soll, David R

    2008-08-26

    The development of Candida albicans biofilms requires two types of adhesion molecule - the Als proteins and Hwp1. Mutational analyses have recently revealed that these molecules play complementary roles, and their characteristics suggest that they may have evolved from primitive mating agglutinins. PMID:18727911

  18. ISOLATION OF INTEGRIN-BASED ADHESION COMPLEXES

    PubMed Central

    Jones, Matthew C.; Humphries, Jonathan D.; Byron, Adam; Millon-Frémillon, Angelique; Robertson, Joseph; Paul, Nikki R.; Ng, Daniel H. J.; Askari, Janet A.; Humphries, Martin J.

    2015-01-01

    The integration of cells with their extracellular environment is facilitated by cell surface adhesion receptors, such as integrins, which play important roles in both normal development and the onset of pathologies. Engagement of integrins with their ligands in the extracellular matrix, or counter receptors on other cells, initiates the intracellular assembly of a wide variety of proteins into adhesion complexes such as focal contacts, focal adhesions and fibrillar adhesions. The proteins recruited to these complexes mediate bidirectional signalling across the plasma membrane and as such help to coordinate and / or modulate the multitude of physical or chemical signals to which the cell is subjected. The protocols in this unit describe two approaches for the isolation or enrichment of proteins contained within integrin-associated adhesion complexes together with their local plasma membrane / cytosolic environments from cells in culture. In the first protocol integrin-associated adhesion structures are affinity isolated using microbeads coated with extracellular ligands or antibodies. The second protocol describes the isolation of ventral membrane preparations that are enriched for adhesion complex structures. The protocols permit the determination of adhesion complex components by subsequent downstream analysis by Western blotting or mass spectrometry. PMID:25727331

  19. Piezoelectric inkjet printing of medical adhesives and sealants

    NASA Astrophysics Data System (ADS)

    Boehm, Ryan D.; Gittard, Shaun D.; Byrne, Jacqueline M. H.; Doraiswamy, Anand; Wilker, Jonathan J.; Dunaway, Timothy M.; Crombez, Rene; Shen, Weidian; Lee, Yuan-Shin; Narayan, Roger J.

    2010-07-01

    Piezoelectric inkjet printing is a noncontact process that enables microscale processing of biological materials. In this research summary, the use of piezoelectric inkjet printing for patterning medical adhesives and sealants, including a two-component polyethylene glycol hydrogel-based medical sealant, an N-butyl cyanoacrylate tissue adhesive, and a mussel adhesive protein biological adhesive, is described The effect of Fe(III) on mussel adhesive protein structure was evaluated by means of atomic force microscopy. The ability to process microscale patterns of medical sealants and adhesives will provide an improvement in tissue joining, including enhanced tissue integrity, reduced bond lines, and decreased adhesive toxicity. Piezoelectric inkjet deposition of medical adhesives and sealants may be used in wound closure, fracture fixation, and microscale vascular surgery.

  20. Adhesive Properties of Model, Filled Elastomeric Adhesives

    Microsoft Academic Search

    Peter Drzal; Elizabeth Cheang; Kenneth Shull

    2000-01-01

    Adhesive properties of a model, filled elastomeric adhesive are measured using an axisymmetic adhesion test with a rigid glass indenter. Experiments with poly(methyl methacrylate)-poly(n-butyl acrylate)-poly(methyl methacrylate) triblock copolymer films are conducted with two types of complementary experiments to resolve the surface and bulk contribution to the adhesive behavior. In the first set of experiments, thermally evaporated gold particles are deposited

  1. Sundew adhesive: a naturally occurring hydrogel.

    PubMed

    Huang, Yujian; Wang, Yongzhong; Sun, Leming; Agrawal, Richa; Zhang, Mingjun

    2015-06-01

    Bioadhesives have drawn increasing interest in recent years, owing to their eco-friendly, biocompatible and biodegradable nature. As a typical bioadhesive, sticky exudate observed on the stalked glands of sundew plants aids in the capture of insects and this viscoelastic adhesive has triggered extensive interests in revealing the implied adhesion mechanisms. Despite the significant progress that has been made, the structural traits of the sundew adhesive, especially the morphological characteristics in nanoscale, which may give rise to the viscous and elastic properties of this mucilage, remain unclear. Here, we show that the sundew adhesive is a naturally occurring hydrogel, consisting of nano-network architectures assembled with polysaccharides. The assembly process of the polysaccharides in this hydrogel is proposed to be driven by electrostatic interactions mediated with divalent cations. Negatively charged nanoparticles, with an average diameter of 231.9 ± 14.8 nm, are also obtained from this hydrogel and these nanoparticles are presumed to exert vital roles in the assembly of the nano-networks. Further characterization via atomic force microscopy indicates that the stretching deformation of the sundew adhesive is associated with the flexibility of its fibrous architectures. It is also observed that the adhesion strength of the sundew adhesive is susceptible to low temperatures. Both elasticity and adhesion strength of the sundew adhesive reduce in response to lowering the ambient temperature. The feasibility of applying sundew adhesive for tissue engineering is subsequently explored in this study. Results show that the fibrous scaffolds obtained from sundew adhesive are capable of increasing the adhesion of multiple types of cells, including fibroblast cells and smooth muscle cells, a property that results from the enhanced adsorption of serum proteins. In addition, in light of the weak cytotoxic activity exhibited by these scaffolds towards a variety of mammal cells, evidence is sufficient to propose that sundew adhesive is a promising nanomaterial worth further exploitation in the field of tissue engineering. PMID:25948615

  2. Enterococcal surface protein Esp is not essential for cell adhesion and intestinal colonization of Enterococcus faecium in mice

    PubMed Central

    2009-01-01

    Background Enterococcus faecium has globally emerged as a cause of hospital-acquired infections with high colonization rates in hospitalized patients. The enterococcal surface protein Esp, identified as a potential virulence factor, is specifically linked to nosocomial clonal lineages that are genetically distinct from indigenous E. faecium strains. To investigate whether Esp facilitates bacterial adherence and intestinal colonization of E. faecium, we used human colorectal adenocarcinoma cells (Caco-2 cells) and an experimental colonization model in mice. Results No differences in adherence to Caco-2 cells were found between an Esp expressing strain of E. faecium (E1162) and its isogenic Esp-deficient mutant (E1162?esp). Mice, kept under ceftriaxone treatment, were inoculated orally with either E1162, E1162?esp or both strains simultaneously. Both E1162 and E1162?esp were able to colonize the murine intestines with high and comparable numbers. No differences were found in the contents of cecum and colon. Both E1162 and E1162?esp were able to translocate to the mesenteric lymph nodes. Conclusion These results suggest that Esp is not essential for Caco-2 cell adherence and intestinal colonization or translocation of E. faecium in mice. PMID:19178704

  3. Sry HMG Box Protein 9-positive (Sox9+) Epithelial Cell Adhesion Molecule-negative (EpCAM?) Biphenotypic Cells Derived from Hepatocytes Are Involved in Mouse Liver Regeneration*

    PubMed Central

    Tanimizu, Naoki; Nishikawa, Yuji; Ichinohe, Norihisa; Akiyama, Haruhiko; Mitaka, Toshihiro

    2014-01-01

    It has been shown that mature hepatocytes compensate tissue damages not only by proliferation and/or hypertrophy but also by conversion into cholangiocyte-like cells. We found that Sry HMG box protein 9-positive (Sox9+) epithelial cell adhesion molecule-negative (EpCAM?) hepatocyte nuclear factor 4?-positive (HNF4?+) biphenotypic cells showing hepatocytic morphology appeared near EpCAM+ ductular structures in the livers of mice fed 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC)-containing diet. When Mx1-Cre:ROSA mice, which were injected with poly(I:C) to label mature hepatocytes, were fed with the DDC diet, we found LacZ+Sox9+ cells near ductular structures. Although Sox9+EpCAM? cells adjacent to expanding ducts likely further converted into ductular cells, the incidence was rare. To know the cellular characteristics of Sox9+EpCAM? cells, we isolated them as GFP+EpCAM? cells from DDC-injured livers of Sox9-EGFP mice. Sox9+EpCAM? cells proliferated and could differentiate to functional hepatocytes in vitro. In addition, Sox9+EpCAM? cells formed cysts with a small central lumen in collagen gels containing Matrigel® without expressing EpCAM. These results suggest that Sox9+EpCAM? cells maintaining biphenotypic status can establish cholangiocyte-type polarity. Interestingly, we found that some of the Sox9+ cells surrounded luminal spaces in DDC-injured liver while they expressed HNF4?. Taken together, we consider that in addition to converting to cholangiocyte-like cells, Sox9+EpCAM? cells provide luminal space near expanded ductular structures to prevent deterioration of the injuries and potentially supply new hepatocytes to repair damaged tissues. PMID:24482234

  4. Leptin, soluble interleukin-6 receptor, C-reactive protein and soluble vascular cell adhesion molecule-1 levels in human coronary atherosclerotic plaque.

    PubMed

    Karaduman, M; Oktenli, C; Musabak, U; Sengul, A; Yesilova, Z; Cingoz, F; Olgun, A; Sanisoglu, S Y; Baysan, O; Yildiz, O; Taslipinar, A; Tatar, H; Kutlu, M; Ozata, M

    2006-03-01

    The aim of the present study was to explore the relationship between tissue levels of leptin, soluble interleukin-6 receptor (sIL-6R), high-sensitive-C-reactive protein (hs-CRP) and soluble vascular cell adhesion molecule-1 (sVCAM-1) in atherosclerotic plaques, and traditional risk factors. Coronary artery specimens were obtained from 35 consecutive patients (26 men and nine women) who underwent coronary artery bypass grafting procedure. The mean tissue levels of leptin, hs-CRP and sIL-6R were significantly higher in patients with diabetes mellitus than without diabetes mellitus. When patients were classified according to the smoking status, the mean tissue levels of leptin, hs-CRP and sIL-6R were significantly higher in current smokers than both former smokers and non-smokers. In addition, the mean tissue levels of leptin and sIL-6R were significantly higher in former smokers than non-smokers. There was a positive association between leptin and hs-CRP, sIL-6R and plasma glucose in all patients. Plasma HDL levels were associated negatively with atherosclerotic tissue levels of leptin. Tissue levels of sIL-6R were associated significantly in a positive manner with leptin, hs-CRP and plasma glucose, while tissue levels of hs-CRP were associated with both leptin and sIL-6R. In conclusion, it is attractive to speculate that hs-CRP, sIL-6R and leptin could act synergistically in course of local inflammatory activity and those molecules may not be just markers of inflammation and cardiovascular risk but are also likely to play a pathogenic role in atheromatous plaque. In addition, atherosclerotic tissue levels of CRP, sIL-6R and leptin were significantly higher in current smokers and patients with diabetes. PMID:16487244

  5. Leptin, soluble interleukin-6 receptor, C-reactive protein and soluble vascular cell adhesion molecule-1 levels in human coronary atherosclerotic plaque

    PubMed Central

    Karaduman, M; Oktenli, C; Musabak, U; Sengul, A; Yesilova, Z; Cingoz, F; Olgun, A; Sanisoglu, S Y; Baysan, O; Yildiz, O; Taslipinar, A; Tatar, H; Kutlu, M; Ozata, M

    2006-01-01

    The aim of the present study was to explore the relationship between tissue levels of leptin, soluble interleukin-6 receptor (sIL-6R), high-sensitive-C-reactive protein (hs-CRP) and soluble vascular cell adhesion molecule-1 (sVCAM-1) in atherosclerotic plaques, and traditional risk factors. Coronary artery specimens were obtained from 35 consecutive patients (26 men and nine women) who underwent coronary artery bypass grafting procedure. The mean tissue levels of leptin, hs-CRP and sIL-6R were significantly higher in patients with diabetes mellitus than without diabetes mellitus. When patients were classified according to the smoking status, the mean tissue levels of leptin, hs-CRP and sIL-6R were significantly higher in current smokers than both former smokers and non-smokers. In addition, the mean tissue levels of leptin and sIL-6R were significantly higher in former smokers than non-smokers. There was a positive association between leptin and hs-CRP, sIL-6R and plasma glucose in all patients. Plasma HDL levels were associated negatively with atherosclerotic tissue levels of leptin. Tissue levels of sIL-6R were associated significantly in a positive manner with leptin, hs-CRP and plasma glucose, while tissue levels of hs-CRP were associated with both leptin and sIL-6R. In conclusion, it is attractive to speculate that hs-CRP, sIL-6R and leptin could act synergistically in course of local inflammatory activity and those molecules may not be just markers of inflammation and cardiovascular risk but are also likely to play a pathogenic role in atheromatous plaque. In addition, atherosclerotic tissue levels of CRP, sIL-6R and leptin were significantly higher in current smokers and patients with diabetes. PMID:16487244

  6. Nanofibrous adhesion: the twin of gecko adhesion.

    PubMed

    Gong, Guangming; Zhou, Chen; Wu, Juntao; Jin, Xu; Jiang, Lei

    2015-04-28

    Inspired by dusty spider dragline silk, we studied the adhesive interaction between artificial nanofibers and their aerosol surroundings. The nanofibers are found to be able to actively capture particulate matters from the environment, exactly as the spider dragline silk does. Examinations prove that such nanofibrous adhesion is insensitive to the chemical nature of the fibers and the physical states of the particulate matter and depends only on the fiber diameters. Such facts indicate that nanofibrous adhesion is a case of dry adhesion, mainly governed by van der Waals force, sharing the same mechanism to gecko adhesion. Nanofibrous adhesion is of great importance and has promising potential. For instance, in this work, nanofibers are fabricated into a thin and translucent filter, which has a filtration performance, as high as 95%, that easily outperformed ordinary ones. We believe that this adhesive property of nanofibers will open up broader applications in both scientific and industrial fields. PMID:25602975

  7. cDNA cloning reveals the molecular structure of a sperm surface protein, PH-20, involved in sperm-egg adhesion and the wide distribution of its gene among mammals

    PubMed Central

    1990-01-01

    Sperm binding to the egg zona pellucida in mammals is a cell-cell adhesion process that is generally species specific. The guinea pig sperm protein PH-20 has a required function in sperm adhesion to the zona pellucida of guinea pig eggs. PH-20 is located on both the sperm plasma membrane and acrosomal membrane. We report here the isolation and sequence of a full-length cDNA for PH-20 (available from EMBL/GenBank/DDBJ under accession number X56332). The derived amino acid sequence shows a mature protein of 468 amino acids containing six N-linked glycosylation sites and twelve cysteines, eight of which are tightly clustered near the COOH terminus. The sequence indicates PH-20 is a novel protein with no relationship to the mouse sperm adhesion protein galactosyl transferase and no significant homology with other known proteins. The two PH-20 populations, plasma membrane and acrosomal membrane, could arise because one form of PH-20 is encoded and differentially targeted at different spermatogenic stages. Alternatively, two different forms of PH-20 could be encoded. Our evidence thus far reveals only one sequence coding for PH-20: Southern blots of guinea pig genomic DNA indicated there is a single PH-20 gene, Northern blots showed a single size PH-20 message (approximately 2.2 kb), and no sequence variants were found among the sequenced cDNA clones. Cross-species Southern blots reveal the presence of a homologue of the PH-20 gene in mouse, rat, hamster, rabbit, bovine, monkey, and human genomic DNA, showing the PH-20 gene is conserved among mammals. Since genes for zona glycoproteins are also conserved among mammals, the general features of sperm and zona proteins involved in mammalian sperm-egg adhesion may have been evolutionarily maintained. Species specificity may result from limited changes in these molecules, either in their binding domains or in other regions that affect the ability of the binding domains to interact. PMID:2269661

  8. Adhesive Properties of Model, Filled Elastomeric Adhesives

    NASA Astrophysics Data System (ADS)

    Drzal, Peter; Cheang, Elizabeth; Shull, Kenneth

    2000-03-01

    Adhesive properties of a model, filled elastomeric adhesive are measured using an axisymmetic adhesion test with a rigid glass indenter. Experiments with poly(methyl methacrylate)-poly(n-butyl acrylate)-poly(methyl methacrylate) triblock copolymer films are conducted with two types of complementary experiments to resolve the surface and bulk contribution to the adhesive behavior. In the first set of experiments, thermally evaporated gold particles are deposited onto the triblock copolymer to yield gold coatings with equivalent thicknesses of 100 nm or less. The axisymmetric adhesion test is used to measure the force required to separate the glass indenter from the gold coated triblock copolymer substrates. The work of adhesion decreases with increasing thickness of the gold coating. This result is attributed to a reduction in the true area of contact between the indenter and the adhesive upon the addition of the metal particle layer. In the second set of experiments, effects of rigid particles on the bulk mechanical properties and adhesive response are probed by adding spherical aluminum oxide particles to the adhesive. In both sets of experiments, approaches based on linear elastic fracture mechanics are used to quantify the adhesive response.

  9. P-Cadherin Promotes Cell-Cell Adhesion and Counteracts Invasion in Human Melanoma

    Microsoft Academic Search

    Veerle Van Marck; Karolien Van Den Bossche; Veronique Stove; Joana Paredes

    2005-01-01

    Malignant transformation of melanocytes frequently coin- cides with alterations in epithelial cadherin (E-cadherin) expression, switching on of neural cadherin (N-cadherin), and, when progressed to a metastatic stage, loss of membranous placental cadherin (P-cadherin). In vitro studies of melanoma cell lines have shown invasion suppressor and promoter roles for E-cadherin and N-cadherin, respectively. In the present study, we investigated the effect

  10. BopA Does Not Have a Major Role in the Adhesion of Bifidobacterium bifidum to Intestinal Epithelial Cells, Extracellular Matrix Proteins, and Mucus

    PubMed Central

    Kainulainen, Veera; Reunanen, Justus; Hiippala, Kaisa; Guglielmetti, Simone; Vesterlund, Satu; Palva, Airi

    2013-01-01

    The ability of bifidobacteria to adhere to the intestine of the human host is considered to be important for efficient colonization and achieving probiotic effects. Bifidobacterium bifidum strains DSM20456 and MIMBb75 adhere well to the human intestinal cell lines Caco-2 and HT-29. The surface lipoprotein BopA was previously described to be involved in mediating adherence of B. bifidum to epithelial cells, but thioacylated, purified BopA inhibited the adhesion of B. bifidum to epithelial cells in competitive adhesion assays only at very high concentrations, indicating an unspecific effect. In this study, the role of BopA in the adhesion of B. bifidum was readdressed. The gene encoding BopA was cloned and expressed without its lipobox and hydrophobic signal peptide in Escherichia coli, and an antiserum against the recombinant BopA was produced. The antiserum was used to demonstrate the abundant localization of BopA on the cell surface of B. bifidum. However, blocking of B. bifidum BopA with specific antiserum did not reduce adhesion of bacteria to epithelial cell lines, arguing that BopA is not an adhesin. Also, adhesion of B. bifidum to human colonic mucin and fibronectin was found to be BopA independent. The recombinant BopA bound only moderately to human epithelial cells and colonic mucus, and it failed to bind to fibronectin. Thus, our results contrast the earlier findings on the major role of BopA in adhesion, indicating that the strong adhesion of B. bifidum to epithelial cell lines is BopA independent. PMID:24014530

  11. BopA does not have a major role in the adhesion of Bifidobacterium bifidum to intestinal epithelial cells, extracellular matrix proteins, and mucus.

    PubMed

    Kainulainen, Veera; Reunanen, Justus; Hiippala, Kaisa; Guglielmetti, Simone; Vesterlund, Satu; Palva, Airi; Satokari, Reetta

    2013-11-01

    The ability of bifidobacteria to adhere to the intestine of the human host is considered to be important for efficient colonization and achieving probiotic effects. Bifidobacterium bifidum strains DSM20456 and MIMBb75 adhere well to the human intestinal cell lines Caco-2 and HT-29. The surface lipoprotein BopA was previously described to be involved in mediating adherence of B. bifidum to epithelial cells, but thioacylated, purified BopA inhibited the adhesion of B. bifidum to epithelial cells in competitive adhesion assays only at very high concentrations, indicating an unspecific effect. In this study, the role of BopA in the adhesion of B. bifidum was readdressed. The gene encoding BopA was cloned and expressed without its lipobox and hydrophobic signal peptide in Escherichia coli, and an antiserum against the recombinant BopA was produced. The antiserum was used to demonstrate the abundant localization of BopA on the cell surface of B. bifidum. However, blocking of B. bifidum BopA with specific antiserum did not reduce adhesion of bacteria to epithelial cell lines, arguing that BopA is not an adhesin. Also, adhesion of B. bifidum to human colonic mucin and fibronectin was found to be BopA independent. The recombinant BopA bound only moderately to human epithelial cells and colonic mucus, and it failed to bind to fibronectin. Thus, our results contrast the earlier findings on the major role of BopA in adhesion, indicating that the strong adhesion of B. bifidum to epithelial cell lines is BopA independent. PMID:24014530

  12. Homo and heterodimerization of APP family members promotes intercellular adhesion

    Microsoft Academic Search

    Peter Soba; Simone Eggert; Katja Wagner; Hanswalter Zentgraf; Katjuscha Siehl; Sylvia Kreger; Alexander Löwer; Andreas Langer; Gunter Merdes; Renato Paro; Colin L Masters; Ulrike Müller; Stefan Kins; Konrad Beyreuther

    2005-01-01

    The amyloid precursor protein (APP) plays a central role in Alzheimer's disease, but its physiological function and that of its mammalian paralogs, the amyloid precursor-like proteins 1 and 2 (APLPs), is still poorly understood. APP has been proposed to form dimers, a process that could promote cell adhesion via trans-dimerization. We investi- gated the dimerization and cell adhesion properties of

  13. Electrically controlled DNA adhesion

    NASA Astrophysics Data System (ADS)

    Erdmann, Matthias; David, Ralf; Fornof, Ann; Gaub, Hermann E.

    2010-02-01

    The ability to control the interaction of polyelectrolytes, such as DNA or proteins, with charged surfaces is of pivotal importance for a multitude of biotechnological applications. Previously, we measured the desorption forces of single polymers on charged surfaces using an atomic force microscope. Here, we show that the adhesion of DNA on gold electrodes modified with self-assembled monolayers can be biased by the composition of the monolayer and externally controlled by means of the electrode potential. Positive potentials induced DNA adsorption onto OH-terminated electrodes with adhesion forces up to 25 pN (at +0.5 V versus Ag/AgCl), whereas negative potentials suppressed DNA adsorption. The measured contributions of the DNA backbone phosphate charges and the doubly charged terminal phosphate on adsorption agreed with a model based on the Gouy-Chapman theory. Experiments on an NH2-terminated electrode revealed a similar force modulation range of the coulomb component of the desorption force. These findings are important for the development of new DNA-based biochips or supramolecular structures.

  14. 5-HT1A receptors mediate detrimental effects of cocaine on long-term potentiation and expression of polysialylated neural cell adhesion molecule protein in rat dentate gyrus.

    PubMed

    Grzegorzewska, M; Ma?kowiak, M; Wedzony, K; Hess, G

    2010-03-10

    The present study investigated the involvement of 5-HT(1A) receptors in the inhibitory effect of single administration of cocaine (COC, 15 mg/kg i.p.) on the induction of long-term potentiation (LTP) in slices of rat dentate gyrus (DG), prepared 30 min and 2 days after COC administration. These effects of COC were blocked by an antagonist of 5-HT(1A) receptors, WAY 100635 (0.4 mg/kg i.p.), which had been administered 20 min before COC. The detrimental effect of COC on LTP in slices prepared 30 min after COC administration could be prevented by blocking glucocorticoid receptors (GRs) using mifepristone (RU 38486, 10 mg/kg s.c. given 1 h before COC), similar as in slices obtained 2 days after COC as reported previously [Ma?kowiak et al. (2008) Eur J Neurosci 27:2928-2937]. After a single administration of an agonist of 5-HT(1A) receptors, 8-OH-DPAT, (0.5 mg/kg i.p.), the level of LTP in slices prepared 2 days later was significantly decreased resembling the effect of COC. This effect of 8-OH-DPAT was antagonized by WAY 100635 (0.4 mg/kg i.p.), administered 20 min before 8-OH-DPAT and by RU 38486, given 1 h before 8-OH-DPAT. COC-induced inhibition of LTP could be blocked by the inhibitor of mitogen-activated protein kinase kinase 1/2 (MEK1/2), SL 327 (50 mg/kg i.p.), administered 1 h before COC, but not by the inhibitor of phosphatidylinositol 3-kinase (PI3-kinase), LY 294002 (80 mg/kg i.p.). COC-induced reduction in the number of polysialylated neural cell adhesion molecule (PSA-NCAM)-positive neurons in rat dentate gyrus could also be prevented by WAY 100635, given 20 min before COC. These data indicate that the indirect 5-HT(1A) receptor activation by a single COC administration and subsequent stimulation of extracellular signal-regulated kinases (ERK 1/2) signaling pathway result in a decrease of the potential for long-term increase in synaptic efficacy in rat DG lasting at least two but less than 7 days, most likely via activation of the hypothalamic-pituitary-adrenal (HPA) axis. PMID:20006974

  15. Theory of Force Regulation by Nascent Adhesion Sites

    PubMed Central

    Bruinsma, Robijn

    2005-01-01

    The mechanical coupling of a cell with the extracellular matrix relies on adhesion sites, clusters of membrane-associated proteins that communicate forces generated along the F-Actin filaments of the cytoskeleton to connecting tissue. Nascent adhesion sites have been shown to regulate these forces in response to tissue rigidity. Force-regulation by substrate rigidity of adhesion sites with fixed area is not possible for stationary adhesion sites, according to elasticity theory. A simple model is presented to describe force regulation by dynamical adhesion sites. PMID:15849245

  16. Ins and Outs of Microbial Adhesion

    NASA Astrophysics Data System (ADS)

    Virji, Mumtaz

    Microbial adhesion is generally a complex process, involving multiple adhesins on a single microbe and their respective target receptors on host cells. In some situations, various adhesins of a microbe may co-operate in an apparently hierarchical and sequential manner whereby the first adhesive event triggers the target cell to express receptors for additional microbial adhesins. In other instances, adhesins may act in concert leading to high avidity interactions, often a prelude to cellular invasion and tissue penetration. Mechanisms used to target the host include both lectin-like interactions and protein-protein interactions; the latter are often highly specific for the host or a tissue within the host. This reflective chapter aims to offer a point of view on microbial adhesion by presenting some experiences and thoughts especially related to respiratory pathogens and explore if there can be any future hope of controlling bacterial infections via preventing adhesion or invasion stages of microbial pathogenesis.

  17. Sealing microcircuits with adhesives

    NASA Technical Reports Server (NTRS)

    Licari, J. J.; Perkins, K. L.

    1979-01-01

    Report describes study of adhesive-sealed packages for hybrid microcircuits. Ten commercially available adhesives were used to seal metal and ceramic packages and were tested for moisture resistance at high humidity.

  18. Neurite Outgrowth Stimulated by Neural Cell Adhesion Molecules Requires Growth-Associated Protein43 (GAP43) Function and Is Associated with GAP43 Phosphorylation in Growth Cones

    Microsoft Academic Search

    Karina F. Meiri; Jane L. Saffell; Frank S. Walsh; Patrick Doherty

    1998-01-01

    The mechanisms whereby cell adhesion molecules (CAMs) pro- mote axonal growth and synaptic plasticity are poorly under- stood. Here we show that the neurite outgrowth stimulated by NCAM-mediated fibroblast growth factor (FGF) receptor acti- vation in cerebellar granule cells is associated with increased GAP-43 phosphorylation on serine-41. In contrast, neither NCAM nor FGF was able to stimulate neurite outgrowth in

  19. the protein adsorption assay, and onto a glass substrate for the cell and platelet adhesion assay. The samples were subsequently heated to

    E-print Network

    Rogers, John A.

    . This was then centrifuged at 1300 g for 10 min to separate the platelets from the plasma. The platelets were labeled with 5. The number of stained cells was counted using a hemocytometer. Platelet Adhesion Assay: Blood was collected in a heparin-contain- ing polypropylene tube from a 22-year-old man with his consent. The blood, containing 2 U

  20. Rho and Rac-dependent Assembly of Focal Adhesion Complexes and Actin Filaments in Permeabilized Fibroblasts: An Essential Role for Ezrin\\/Radixin\\/Moesin Proteins

    Microsoft Academic Search

    Deborah J. G. Mackay; Fred Esch; Heinz Furthmayr; Alan Hall

    1997-01-01

    The small GTPases Rho and Rac regulate actin filament assembly and the formation of integrin adhesion complexes to produce stress fibers and lamel- lipodia, respectively, in mammalian cells. Although nu- merous candidate effectors that might mediate these responses have been identified using the yeast two- hybrid and affinity purification techniques, their cellu- lar roles remain unclear. We now describe a

  1. A low elastic modulus Ti-Nb-Hf alloy bioactivated with an elastin-like protein-based polymer enhances osteoblast cell adhesion and spreading.

    PubMed

    González, Marta; Salvagni, Emiliano; Rodríguez-Cabello, José C; Rupérez, Elisa; Gil, Francisco J; Peña, Javier; Manero, José M

    2013-03-01

    ?-type titanium alloys with low Young's modulus are desirable to reduce stress shielding effect and enhance bone remodeling for implants used to substitute failed hard tissue. For biomaterials application, the surface bioactivity is necessary to achieve optimal osseointegration. In the previous work, the low elastic modulus (43 GPa) Ti-25Nb-16Hf (wt %) alloy was mechanically and microstructurally characterized. In the present work, the biological behavior of Ti-25Nb-16Hf was studied. The biological response was improved by surface modification. The metal surface was modified by oxygen plasma and subsequently silanized with 3-chloropropyl(triethoxy)silane for covalent immobilization of the elastin-like polymer. The elastin-like polymer employed exhibits RGD bioactive motives inspired to the extracellular matrix in order to improve cell adhesion and spreading. Upon modification, the achieved surface presented different physical and chemical properties, such as surface energy and chemical composition. Subsequently, osteoblast adhesion, cell numbers, and differentiation studies were performed to correlate surface properties and cell response. The general tendency was that the higher surface energy the higher cell adhesion. Furthermore, cell culture and immunofluorescence microscopy images demonstrated that RGD-modified surfaces improved adhesion and spreading of the osteoblast cell type. PMID:22962002

  2. The C. elegans EMAP-like protein, ELP-1 is required for touch sensation and associates with microtubules and adhesion complexes

    E-print Network

    Hueston, Jennifer L.; Herren, Gina Purinton; Cueva, Juan G.; Buechner, Matthew; Lundquist, Erik A.; Goodman, Miriam B.; Suprenant, Kathy A.

    2008-11-17

    tissues. In embryos, ELP-1 is expressed in the hypodermis. In larvae and adults, ELP-1 is expressed in the body wall, spermatheca and vulval muscles, intestine, and hypodermal seam cells. In muscle, ELP-1 is associated with adhesion complexes near the cell...

  3. Single-molecule mechanics of mussel adhesion

    NASA Astrophysics Data System (ADS)

    Lee, Haeshin; Scherer, Norbert F.; Messersmith, Phillip B.

    2006-08-01

    The glue proteins secreted by marine mussels bind strongly to virtually all inorganic and organic surfaces in aqueous environments in which most adhesives function poorly. Studies of these functionally unique proteins have revealed the presence of the unusual amino acid 3,4-dihydroxy-L-phenylalanine (dopa), which is formed by posttranslational modification of tyrosine. However, the detailed binding mechanisms of dopa remain unknown, and the chemical basis for mussels' ability to adhere to both inorganic and organic surfaces has never been fully explained. Herein, we report a single-molecule study of the substrate and oxidation-dependent adhesive properties of dopa. Atomic force microscopy (AFM) measurements of a single dopa residue contacting a wet metal oxide surface reveal a surprisingly high strength yet fully reversible, noncovalent interaction. The magnitude of the bond dissociation energy as well as the inability to observe this interaction with tyrosine suggests that dopa is critical to adhesion and that the binding mechanism is not hydrogen bond formation. Oxidation of dopa, as occurs during curing of the secreted mussel glue, dramatically reduces the strength of the interaction to metal oxide but results in high strength irreversible covalent bond formation to an organic surface. A new picture of the interfacial adhesive role of dopa emerges from these studies, in which dopa exploits a remarkable combination of high strength and chemical multifunctionality to accomplish adhesion to substrates of widely varying composition from organic to metallic. 3,4-dihydroxylphenylalanine | atomic force microscopy | mussel adhesive protein

  4. Integrins and cadherins join forces to form adhesive networks

    PubMed Central

    Weber, Gregory F.; Bjerke, Maureen A.; DeSimone, Douglas W.

    2011-01-01

    Cell–cell and cell–extracellular-matrix (cell–ECM) adhesions have much in common, including shared cytoskeletal linkages, signaling molecules and adaptor proteins that serve to regulate multiple cellular functions. The term ‘adhesive crosstalk’ is widely used to indicate the presumed functional communication between distinct adhesive specializations in the cell. However, this distinction is largely a simplification on the basis of the non-overlapping subcellular distribution of molecules that are involved in adhesion and adhesion-dependent signaling at points of cell–cell and cell–substrate contact. The purpose of this Commentary is to highlight data that demonstrate the coordination and interdependence of cadherin and integrin adhesions. We describe the convergence of adhesive inputs on cell signaling pathways and cytoskeletal assemblies involved in regulating cell polarity, migration, proliferation and survival, differentiation and morphogenesis. Cell–cell and cell–ECM adhesions represent highly integrated networks of protein interactions that are crucial for tissue homeostasis and the responses of individual cells to their adhesive environments. We argue that the machinery of adhesion in multicellular tissues comprises an interdependent network of cell–cell and cell–ECM interactions and signaling responses, and not merely crosstalk between spatially and functionally distinct adhesive specializations within cells. PMID:21444749

  5. Joining Tubes With Adhesive

    NASA Technical Reports Server (NTRS)

    Bateman, W. A.

    1984-01-01

    Cylindrical tubes joined together, end to end, by method employing adhesive, tapered ends, and spacing wires. Tapered joint between tubular structural elements provides pressure between bonding surfaces during adhesive curing. Spacing wires prevent adhesive from being scraped away when one element inserted in other. Method developed for assembling structural elements made of composite materials.

  6. Adhesion-induced receptor segregation and adhesion plaque formation: A model membrane study.

    PubMed Central

    Kloboucek, A; Behrisch, A; Faix, J; Sackmann, E

    1999-01-01

    A model system to study the control of cell adhesion by receptor-mediated specific forces, universal interactions, and membrane elasticity is established. The plasma membrane is mimicked by reconstitution of homophilic receptor proteins into solid supported membranes and, together with lipopolymers, into giant vesicles with the polymers forming an artificial glycocalix. The homophilic cell adhesion molecule contact site A, a lipid-anchored glycoprotein from cells of the slime mold Dictyostelium discoideum, is used as receptor. The success of the reconstitution, the structure and the dynamics of the model membranes are studied by various techniques including film balance techniques, micro fluorescence, fluorescence recovery after photobleaching, electron microscopy, and phase contrast microscopy. The interaction of the functionalized giant vesicles with the supported bilayer is studied by reflection interference contrast microscopy, and the adhesion strength is evaluated quantitatively by a recently developed technique. At low receptor concentrations adhesion-induced receptor segregation in the membranes leads to decomposition of the contact zone between membranes into domains of strong (receptor-mediated) adhesion and regions of weak adhesion while continuous zones of strong adhesion form at high receptor densities. The adhesion strengths (measured in terms of the spreading pressure S) of the various states of adhesion are obtained locally by analysis of the vesicle contour near the contact line in terms of elastic boundary conditions of adhesion: the balance of tensions and moments. The spreading pressure of the weak adhesion zones is S approximately 10(-9) J/m(2) and is determined by the interplay of gravitation and undulation forces whereas the spreading pressure of the tight adhesion domains is of the order S approximately 10(-6) J/m(2). PMID:10512849

  7. Elevated levels of StAR-related lipid transfer protein 3 alter cholesterol balance and adhesiveness of breast cancer cells: potential mechanisms contributing to progression of HER2-positive breast cancers.

    PubMed

    Vassilev, Boris; Sihto, Harri; Li, Shiqian; Hölttä-Vuori, Maarit; Ilola, Jaakko; Lundin, Johan; Isola, Jorma; Kellokumpu-Lehtinen, Pirkko-Liisa; Joensuu, Heikki; Ikonen, Elina

    2015-04-01

    The STARD3 gene belongs to the minimal amplicon in HER2-positive breast cancers and encodes a cholesterol-binding membrane protein. To study how elevated StAR-related lipid transfer protein 3 (StARD3) expression affects breast cancer cells, we generated MCF-7 cells stably overexpressing StARD3-green fluorescent protein. We found that StARD3-overexpressing cells exhibited nonadherent morphological features, had increased Src levels, and had altered cholesterol balance, as evidenced by elevated mRNA levels of the cholesterol biosynthesis rate-limiting enzyme 3-hydroxy-3-methylglutaryl-coenzyme A reductase, and increased plasma membrane cholesterol content. On removal of serum and insulin from the culture medium, the morphological characteristics of the StARD3-overexpressing cells changed, the cells became adherent, and they developed enlarged focal adhesions. Under these conditions, the StARD3-overexpressing cells maintained elevated Src and plasma membrane cholesterol content and showed increased phosphorylation of focal adhesion kinase. In two Finnish nationwide patient cohorts, approximately 10% (212/2220) breast cancers exhibited high StARD3 protein levels, which was strongly associated with HER2 amplification; several factors related to poor disease outcome and poor breast cancer-specific survival. In addition, high StARD3 levels in breast cancers were associated with elevated 3-hydroxy-3-methylglutaryl-coenzyme A reductase mRNA levels and anti-Src-Tyr416 immunoreactivity. These results provide evidence that StARD3 overexpression results in increased cholesterol biosynthesis and Src kinase activity in breast cancer cells and suggest that elevated StARD3 expression may contribute to breast cancer aggressiveness by increasing membrane cholesterol and enhancing oncogenic signaling. PMID:25681734

  8. Inhibition of Enteropathogenic Escherichia coli (EPEC) Adhesion to HeLa Cells by Human Colostrum: Detection of Specific slgA Related to EPEC Outer-Membrane Proteins

    Microsoft Academic Search

    Lilia M. Camara; Solange B. Carbonare; Lourdes M. Silva; Magda M. S. Carneiro-Sampaio

    1994-01-01

    Human colostrum and a high molecular weight colostrum fraction (HMWF; > 14,000D) prevented the adhesion of localized adherent (LA+) O111:H––enteropathogenic Escherichia coli (EPEC) to HeLa cells. This effect was abolished after absorption with an O111:H––LA+ EPEC strain, but absorption with a LA- strain of same serotype had no effect on the process. A low molecular weight fraction (< 14,000 D),

  9. Cardamonin Suppresses TGF-?1-Induced Epithelial Mesenchymal Transition via Restoring Protein Phosphatase 2A Expression

    PubMed Central

    Kim, Eun Ji; Kim, Hyun Ji; Park, Mi Kyung; Kang, Gyeung Jin; Byun, Hyun Jung; Lee, Ho; Lee, Chang Hoon

    2015-01-01

    Epithelial mesenchymal transition (EMT) is the first step in metastasis and implicated in the phenotype of cancer stem cells. Therefore, understanding and controlling EMT, are essential to the prevention and cure of metastasis. In the present study, we examined, by Western blot, reverse transcription polymerase chain reaction (RT-PCR), and confocal microscopy, the effects of cardamonin (CDN) on transforming growth factor-?1 (TGF-?1)-induced EMT of A549 lung adenocarcinoma cell lines. TGF-?1 induced expression of N-cadherin and decreased expression of E-cadherin. CDN suppressed N-cadherin expression and restored E-cadherin expression. Further, TGF-?1 induced migration and invasion of A549 cancer cells, which was suppressed by CDN. TGF-?1 induced c-Jun N-terminal kinase (JNK) activation during EMT, but CDN blocked it. Protein serine/threonine phosphatase 2A (PP2A) expression in A549 cancer cells was reduced by TGF-?1 but CDN restored it. The overall data suggested that CDN suppresses TGF-?1-induced EMT via PP2A restoration, making it a potential new drug candidate that controls metastasis. PMID:25767682

  10. Proteomic Analysis of Integrin Adhesion Complexes

    NSDL National Science Digital Library

    Adam Byron (University of Manchester; Wellcome Trust Centre for Cell-Matrix Research REV)

    2011-04-05

    Integrin receptors regulate cell fate by coupling the binding of extracellular adhesion proteins to the assembly of intracellular cytoskeletal and signaling complexes. A detailed, integrative view of adhesion complexes will provide insight into the molecular mechanisms that control cell morphology, survival, movement, and differentiation. To date, membrane receptor–associated signaling complexes have been refractory to proteomic analysis because of their inherent lability and inaccessibility. We developed a methodology to isolate ligand-induced integrin adhesion complexes, and we used this technique to analyze the composition of complexes associated with multiple receptor–ligand pairs and define core and receptor-specific subnetworks. In particular, we identified regulator of chromosome condensation–2 (RCC2) as a component of fibronectin-activated signaling pathways that regulate directional cell movement. The development of this proteomics pipeline provides the means to investigate the molecular composition and function of various adhesion complexes.

  11. Diverse evolutionary paths to cell adhesion.

    PubMed

    Abedin, Monika; King, Nicole

    2010-12-01

    The morphological diversity of animals, fungi, plants, and other multicellular organisms stems from the fact that each lineage acquired multicellularity independently. A prerequisite for each origin of multicellularity was the evolution of mechanisms for stable cell-cell adhesion or attachment. Recent advances in comparative genomics and phylogenetics provide critical insights into the evolutionary foundations of cell adhesion. Reconstructing the evolution of cell junction proteins in animals and their unicellular relatives exemplifies the roles of co-option and innovation. Comparative studies of volvocine algae reveal specific molecular changes that accompanied the evolution of multicellularity in Volvox. Comparisons between animals and Dictyostelium show how commonalities and differences in the biology of unicellular ancestors influenced the evolution of adhesive mechanisms. Understanding the unicellular ancestry of cell adhesion helps illuminate the basic cell biology of multicellular development in modern organisms. PMID:20817460

  12. The soluble form of LR11 protein is a regulator of hypoxia-induced, urokinase-type plasminogen activator receptor (uPAR)-mediated adhesion of immature hematological cells.

    PubMed

    Nishii, Keigo; Nakaseko, Chiaki; Jiang, Meizi; Shimizu, Naomi; Takeuchi, Masahiro; Schneider, Wolfgang J; Bujo, Hideaki

    2013-04-26

    A key property of hematopoietic stem and progenitor cells (HSPCs) regarding differentiation from the self-renewing quiescent to the proliferating stage is their adhesion to the bone marrow (BM) niche. An important molecule involved in proliferation and pool size of HSPCs in the BM is the hypoxia-induced urokinase-type plasminogen activator receptor (uPAR). Here, we show that the soluble form (sLR11) of LR11 (also called SorLA or SORL1) modulates the uPAR-mediated attachment of HSPCs under hypoxic conditions. Immunohistochemical and mRNA expression analyses revealed that hypoxia increased LR11 expression in hematological c-Kit(+) Lin(-) cells. In U937 cells, hypoxia induced a transient rise in LR11 transcription, production of cellular protein, and release of sLR11. Attachment to stromal cells of c-Kit(+) Lin(-) cells of lr11(-/-) mice was reduced by hypoxia much more than of lr11(+/+) animals. sLR11 induced the adhesion of U937 and c-Kit(+) Lin(-) cells to stromal cells. Cell attachment was increased by sLR11 and reduced in the presence of anti-uPAR antibodies. Furthermore, the fraction of uPAR co-immunoprecipitated with LR11 in membrane extracts of U937 cells was increased by hypoxia. CoCl2, a chemical inducer of HIF-1?, enhanced the levels of LR11 and sLR11 in U937 cells. The decrease in hypoxia-induced attachment of HIF-1?-knockdown cells was largely prevented by exogenously added sLR11. Finally, hypoxia induced HIF-1? binding to a consensus binding site in the LR11 promoter. Thus, we conclude that sLR11 regulates the hypoxia-enhanced adhesion of HSPCs via an uPAR-mediated pathway that stabilizes the hematological pool size by controlling cell attachment to the BM niche. PMID:23486467

  13. High insulin enhances neutrophil transendothelial migration through increasing surface expression of platelet endothelial cell adhesion molecule-1 via activation of mitogen activated protein kinase

    Microsoft Academic Search

    M. Okouchi; N. Okayama; S. Imai; H. Omi; M. Shimizu; T. Fukutomi; M. Itoh

    2002-01-01

      Abstract\\u000a \\u000a \\u000a Aims\\/hypothesis. There is increasing evidence that hyperinsulinaemia is linked with the development of atherosclerosis in patients with diabetes.\\u000a However, the mechanisms by which hyperinsulinaemia causes accelerated atherosclerosis, especially with respect to leukocytes\\u000a transendothelial migration, are poorly understood. We examined whether hyperinsulinaemia directly affects neutrophil transendothelial\\u000a migration and surface expression of related endothelial adhesion molecules.\\u000a \\u000a \\u000a \\u000a \\u000a Methods. Experiments on the transmigration

  14. Bio-inspired adhesion: local chemical environments impact adhesive stability

    NASA Astrophysics Data System (ADS)

    Gebbie, Matthew A.; Rapp, Michael V.; Yu, Jing; Wei, Wei; Waite, J. Herbert; Israelachvili, Jacob N.

    2014-03-01

    3,4-dihydroxyphenylalanine (Dopa) is an amino acid that is naturally synthesized by marine mussels and exhibits the unique ability to strongly bind to surfaces in aqueous environments. However, the Dopa functional group undergoes auto-oxidation to a non-adhesive quinone form in neutral to basic pH conditions, limiting the utilization of Dopa in biomedical applications. In this work, we performed direct surface force measurements with in situ electrochemical control across a Dopa-rich native mussel foot protein (mfp-5), as well as three simplified model peptide sequences. We find that the neighboring peptide residues can significantly impact the redox stability of Dopa functional groups, with lysine residues imparting a substantial degree of Dopa redox stabilization. Surprisingly, the local chemical environments only minimally impact the magnitude of the adhesion forces measured between molecularly-smooth mica and gold surfaces. Our results provide molecular level insight into approaches that can be used to mitigate the detrimental impact of Dopa auto-oxidation, thus suggesting new molecular design strategies for improving the performance of Dopa-based underwater adhesives.

  15. Tuning endothelial monolayer adhesion: a neutron reflectivity study

    PubMed Central

    Junghans, Ann; Zebda, Noureddine; Birukov, Konstantin; Majewski, Jaroslaw

    2013-01-01

    Endothelial cells, master gatekeepers of the cardiovascular system, line its inner boundary from the heart to distant capillaries constantly exposed to blood flow. Interendothelial signaling and the monolayers adhesion to the underlying collagen-rich basal lamina are key in physiology and disease. Using neutron scattering, we report the first ever interfacial structure of endothelial monolayers under dynamic flow conditions mimicking the cardiovascular system. Endothelial adhesion (defined as the separation distance ? between the basal cell membrane and solid boundary) is explained using developed interfacial potentials and intramembrane segregation of specific adhesion proteins. Our method provides a powerful tool for the biophysical study of cellular layer adhesion strength in living tissues. PMID:24163142

  16. Neutrophil-activating protein 1/interleukin 8 stimulates the binding activity of the leukocyte adhesion receptor CD11b/CD18 on human neutrophils

    PubMed Central

    1990-01-01

    The cytokine NAP-1/IL-8 is produced by a variety of different cells in response to inflammatory stimuli and elicits several biological responses from PMN. Experiments presented here demonstrate that PMN exposed to NAP-1/IL-8 expressed increased amounts of CD11b/CD18, as well as CD11c/CD18 and CR1, on their cell surface, while expression of Fc gamma RIII and HLA-A,B,C remained essentially unchanged. Increased CD11b/CD18 and CD11c/CD18 appears to correspond with the release of specific granules by NAP-1/IL-8. NAP-1/IL-8 was also a potent stimulator of several of the binding activities of CD11b/CD18. Ligation of EC3bi by CD11b/CD18 was rapidly enhanced by NAP-1/IL-8, but phagocytosis of the ligated particles was not induced by the agonist. In addition, enhanced binding of EC3bi was observed in the absence of an increase in receptor expression as shown with PMN cytoplasts. NAP- 1/IL-8 promoted additional adhesive interactions between CD11b/CD18 and the biosynthetic precursor of LPS, lipid IVa, fibrinogen, and endothelial cells, suggesting that NAP-1/IL-8 may promote leukocyte adhesion in vivo that could lead to recruitment of PMN to sites of tissue inflammation. PMID:1969919

  17. Silicone pressure-sensitive adhesives with selective adhesion characteristics

    Microsoft Academic Search

    Shaow B. Lin

    1996-01-01

    The peel, probe tack, and loop tack adhesion characteristics of peroxide-cured silicone pressure-sensitive adhesives (PSAs) are investigated with respect to adhesive composition, peroxide concentration, and type of substrate. These adhesion properties decrease with increasing benzoyl peroxide concentration and their adhesion values vary noticeably with the substrate type. However, the loop adhesion to 'difficult-to-wet' surfaces (e.g. silicone-coated substrates) can be selectively

  18. Bacterial Adhesion at Synthetic Surfaces

    PubMed Central

    Cunliffe, D.; Smart, C. A.; Alexander, C.; Vulfson, E. N.

    1999-01-01

    A systematic investigation into the effect of surface chemistry on bacterial adhesion was carried out. In particular, a number of physicochemical factors important in defining the surface at the molecular level were assessed for their effect on the adhesion of Listeria monocytogenes, Salmonella typhimurium, Staphylococcus aureus, and Escherichia coli. The primary experiments involved the grafting of groups varying in hydrophilicity, hydrophobicity, chain length, and chemical functionality onto glass substrates such that the surfaces were homogeneous and densely packed with functional groups. All of the surfaces were found to be chemically well defined, and their measured surface energies varied from 15 to 41 mJ · m?2. Protein adsorption experiments were performed with 3H-labelled bovine serum albumin and cytochrome c prior to bacterial attachment studies. Hydrophilic uncharged surfaces showed the greatest resistance to protein adsorption; however, our studies also showed that the effectiveness of poly(ethyleneoxide) (PEO) polymers was not simply a result of its hydrophilicity and molecular weight alone. The adsorption of the two proteins approximately correlated with short-term cell adhesion, and bacterial attachment for L. monocytogenes and E. coli also correlated with the chemistry of the underlying substrate. However, for S. aureus and S. typhimurium a different pattern of attachment occurred, suggesting a dissimilar mechanism of cell attachment, although high-molecular-weight PEO was still the least-cell-adsorbing surface. The implications of this for in vivo attachment of cells suggest that hydrophilic passivating groups may be the best method for preventing cell adsorption to synthetic substrates provided they can be grafted uniformly and in sufficient density at the surface. PMID:10543814

  19. Bacterial adhesion at synthetic surfaces.

    PubMed

    Cunliffe, D; Smart, C A; Alexander, C; Vulfson, E N

    1999-11-01

    A systematic investigation into the effect of surface chemistry on bacterial adhesion was carried out. In particular, a number of physicochemical factors important in defining the surface at the molecular level were assessed for their effect on the adhesion of Listeria monocytogenes, Salmonella typhimurium, Staphylococcus aureus, and Escherichia coli. The primary experiments involved the grafting of groups varying in hydrophilicity, hydrophobicity, chain length, and chemical functionality onto glass substrates such that the surfaces were homogeneous and densely packed with functional groups. All of the surfaces were found to be chemically well defined, and their measured surface energies varied from 15 to 41 mJ. m(-2). Protein adsorption experiments were performed with (3)H-labelled bovine serum albumin and cytochrome c prior to bacterial attachment studies. Hydrophilic uncharged surfaces showed the greatest resistance to protein adsorption; however, our studies also showed that the effectiveness of poly(ethyleneoxide) (PEO) polymers was not simply a result of its hydrophilicity and molecular weight alone. The adsorption of the two proteins approximately correlated with short-term cell adhesion, and bacterial attachment for L. monocytogenes and E. coli also correlated with the chemistry of the underlying substrate. However, for S. aureus and S. typhimurium a different pattern of attachment occurred, suggesting a dissimilar mechanism of cell attachment, although high-molecular-weight PEO was still the least-cell-adsorbing surface. The implications of this for in vivo attachment of cells suggest that hydrophilic passivating groups may be the best method for preventing cell adsorption to synthetic substrates provided they can be grafted uniformly and in sufficient density at the surface. PMID:10543814

  20. Myoferlin depletion elevates focal adhesion kinase and paxillin phosphorylation and enhances cell-matrix adhesion in breast cancer cells.

    PubMed

    Blackstone, B N; Li, R; Ackerman, W E; Ghadiali, S N; Powell, H M; Kniss, D A

    2015-04-15

    Breast cancer is the second leading cause of malignant death among women. A crucial feature of metastatic cancers is their propensity to lose adhesion to the underlying basement membrane as they transition to a motile phenotype and invade surrounding tissue. Attachment to the extracellular matrix is mediated by a complex of adhesion proteins, including integrins, signaling molecules, actin and actin-binding proteins, and scaffolding proteins. Focal adhesion kinase (FAK) is pivotal for the organization of focal contacts and maturation into focal adhesions, and disruption of this process is a hallmark of early cancer invasive potential. Our recent work has revealed that myoferlin (MYOF) mediates breast tumor cell motility and invasive phenotype. In this study we demonstrate that noninvasive breast cancer cell lines exhibit increased cell-substrate adhesion and that silencing of MYOF using RNAi in the highly invasive human breast cancer cell line MDA-MB-231 also enhances cell-substrate adhesion. In addition, we detected elevated tyrosine phosphorylation of FAK (FAK(Y397)) and paxillin (PAX(Y118)), markers of focal adhesion protein activation. Morphometric analysis of PAX expression revealed that RNAi-mediated depletion of MYOF resulted in larger, more elongated focal adhesions, in contrast to cells transduced with a control virus (MDA-231(LVC) cells), which exhibited smaller focal contacts. Finally, MYOF silencing in MDA-MB-231 cells exhibited a more elaborate ventral cytoskeletal structure near focal adhesions, typified by pronounced actin stress fibers. These data support the hypothesis that MYOF regulates cell adhesions and cell-substrate adhesion strength and may account for the high degree of motility in invasive breast cancer cells. PMID:25631868

  1. Ursolic acid, a natural pentacyclic triterpenoid, inhibits intracellular trafficking of proteins and induces accumulation of intercellular adhesion molecule-1 linked to high-mannose-type glycans in the endoplasmic reticulum

    PubMed Central

    Mitsuda, Satoshi; Yokomichi, Tomonobu; Yokoigawa, Junpei; Kataoka, Takao

    2014-01-01

    Ursolic acid (3?-hydroxy-urs-12-en-28-oic acid) is a natural pentacyclic triterpenoid that is present in many plants, including medicinal herbs, and foods. Ursolic acid was initially identified as an inhibitor of the expression of intercellular adhesion molecule-1 (ICAM-1) in response to interleukin-1? (IL-1?). We report here a novel biological activity: ursolic acid inhibits intracellular trafficking of proteins. Ursolic acid markedly inhibited the IL-1?-induced cell-surface ICAM-1 expression in human cancer cell lines and human umbilical vein endothelial cells. By contrast, ursolic acid exerted weak inhibitory effects on the IL-1?-induced ICAM-1 expression at the protein level. Surprisingly, we found that ursolic acid decreased the apparent molecular weight of ICAM-1 and altered the structures of N-linked oligosaccharides bound to ICAM-1. Ursolic acid induced the accumulation of ICAM-1 in the endoplasmic reticulum, which was linked mainly to high-mannose-type glycans. Moreover, in ursolic-acid-treated cells, the Golgi apparatus was fragmented into pieces and distributed over the cells. Thus, our results reveal that ursolic acid inhibits intracellular trafficking of proteins and induces the accumulation of ICAM-1 linked to high-mannose-type glycans in the endoplasmic reticulum. PMID:24649404

  2. The chemistry of stalked barnacle adhesive (Lepas anatifera)

    PubMed Central

    Jonker, Jaimie-Leigh; Morrison, Liam; Lynch, Edward P.; Grunwald, Ingo; von Byern, Janek; Power, Anne Marie

    2015-01-01

    The results of the first chemical analysis of the adhesive of Lepas anatifera, a stalked barnacle, are presented. A variety of elements were identified in scanning electron microscopy with energy dispersive spectrometry (SEM-EDS) of the adhesive, including Na, Mg, Ca, Cl, S, Al, Si, K and Fe; however, protein–metal interactions were not detected in Raman spectra of the adhesive. Elemental signatures from SEM-EDS of L. anatifera adhesive glands were less varied. Phosphorous was mostly absent in adhesive samples; supporting previous studies showing that phosphoserines do not play a significant role in adult barnacle adhesion. Disulfide bridges arising from Cys dimers were also investigated; Raman analysis showed weak evidence for S–S bonds in L. anatifera. In addition, there was no calcium carbonate signal in the attenuated total reflectance Fourier transform infrared spectra of L. anatifera adhesive, unlike several previous studies in other barnacle species. Significant differences were observed between the Raman spectra of L. anatifera and Balanus crenatus; these and a range of Raman peaks in the L. anatifera adhesive are discussed. Polysaccharide was detected in L. anatifera adhesive but the significance of this awaits further experiments. The results demonstrate some of the diversity within barnacle species in the chemistry of their adhesives. PMID:25657841

  3. Neuron adhesion and strengthening

    NASA Astrophysics Data System (ADS)

    Rocha, Aracely; Jian, Kuihuan; Ko, Gladys; Liang, Hong

    2010-07-01

    Understanding the neuron/material adhesion is important for neuron stimulation and growth. The current challenges remain in the lack of precision of measuring techniques and understanding the behavior of neuron. Here, we report a fluid shear method to investigate adhesion at the neuron/poly-D-lysine interface. In this study, the adhesion of 12-day-old chick embryo-retina neurons cultured on poly-D-lysine coated glass coverslips was measured via parallel disk rotational flow. The shear stress experienced by the cells increases with the disk radius. There is a critical point along the radius (Rc) where the stress experienced by the neurons equals their adhesion. The measured Rc can be used to calculate the neuron adhesion. Our results demonstrate that neurons adhered to the poly-D-lysine had a strain hardening effect. The adhesive shear stress of the neuron-material increased with applied shear (?a). When the ?a reached or exceeded the value of 40 dyn/cm2, the adhesion remained constant at approximately 30 dyn/cm2. The present work allowed us not only to quantify the adhesive strength and force but also to evaluate the value of strain hardening at the neuron/poly-D-lysine interface.

  4. LARC-13 adhesive development

    NASA Technical Reports Server (NTRS)

    Hill, S. G.; Sheppard, C. H.; Johnson, J. C.

    1980-01-01

    A LARC-13 type adhesive system was developed and property data obtained that demonstrated improved thermomechanical properties superior to base LARC-13 adhesive. An improved adhesive for 589 K (600 F) use was developed by physical or chemical modification of LARC-13. The adhesive was optimized for titanium and composite bonding, and a compatible surface preparation for titanium and composite substrates was identified. The data obtained with the improved adhesive system indicated it would meet the 589 K (600 F) properties desired for application on space shuttle components. Average titanium lap shear data were: (1) 21.1 MPa (3355 psi) at RT, (2) 13.0 MPa (1881 psi) at 600 F, and (3) 16.4 MPa (2335) after aging 125 hours at 600 F and tested at 600 F.

  5. Plasmin induces intercellular adhesion molecule 1 expression in human endothelial cells via nuclear factor-?B/mitogen-activated protein kinases-dependent pathways.

    PubMed

    Li, Qun; Syrovets, Tatiana; Simmet, Thomas; Ding, Jiazeng; Xu, Jianzhong; Chen, Wendong; Zhu, Dingliang; Gao, Pingjin

    2013-02-01

    Activation of endothelial cells (ECs) by proinflammatory stimuli triggers expression of cellular adhesion molecules including intercellular adhesion molecule 1 (ICAM-1) on the cell surface. Such molecules mediate the transendothelial migration of inflammatory cells, which is an early key step of atherogenesis. We have previously demonstrated that plasmin activates human inflammatory cells via the annexin A2 heterotetramer (A2t). Here we show that human umbilical vein endothelial cells (HUVECs) and human microvascular endothelial cells express high amounts of A2t, as shown by Western blotting, fluorescence microscopy and flow cytometry. Activation of HUVEC by plasmin led to cleavage of the annexin A2 subunit of the receptor complex, followed by the activation of Akt/nuclear factor (NF)-?B signaling, and phosphorylation of MAP kinases p38 and ERK1/2. Further, plasmin stimulates the NF-?B/p38-dependent expression of ICAM-1 by HUVEC. The plasmin-induced activation of cells was abolished when annexin A2 was down-regulated by small-interfering RNA. In vivo, we show co-localization of the ECs marker CD31 with the plasmin receptor A2t and ICAM-1 in human atherosclerotic plaques of human femoral arteries, which also exhibit activated NF-?B signaling as revealed by immunofluorescence staining for phosphorylated I?B?. In addition, plasma of patients with advanced atherosclerosis exhibited enhanced plasmin activity and up-regulated levels of plasmin-?2-antiplasmin. These data point to a previously unrecognized functional role of plasmin in EC biology, which could be of particular relevance in the development of atherosclerosis. PMID:23576799

  6. ?-CATENIN: AT THE JUNCTION OF INTERCELLULAR ADHESION AND ACTIN DYNAMICS

    PubMed Central

    Kobielak, Agnieszka; Fuchs, Elaine

    2008-01-01

    ?-catenin has often been considered to be a non-regulatory intercellular adhesion protein, in contrast to ?-catenin, which has well-documented dual roles in cell–cell adhesion and signal transduction. Recently, however, ?-catenin has been found to be important not only in connecting the E-cadherin–?-catenin complex to the actin cytoskeleton, but also in coordinating actin dynamics and inversely correlating cell adhesion with proliferation. As the number of ?-catenin-interacting partners increases, intriguing new connections imply even more complex regulatory functions for this protein. PMID:15366705

  7. Discriminatory bio-adhesion over nano-patterned polymer brushes

    NASA Astrophysics Data System (ADS)

    Gon, Saugata

    Surfaces functionalized with bio-molecular targeting agents are conventionally used for highly-specific protein and cell adhesion. This thesis explores an alternative approach: Small non-biological adhesive elements are placed on a surface randomly, with the rest of the surface rendered repulsive towards biomolecules and cells. While the adhesive elements themselves, for instance in solution, typically exhibit no selectivity for various compounds within an analyte suspension, selective adhesion of targeted objects or molecules results from their placement on the repulsive surface. The mechanism of selectivity relies on recognition of length scales of the surface distribution of adhesive elements relative to species in the analyte solution, along with the competition between attractions and repulsions between various species in the suspension and different parts of the collecting surface. The resulting binding selectivity can be exquisitely sharp; however, complex mixtures generally require the use of multiple surfaces to isolate the various species: Different components will be adhered, sharply, with changes in collector composition. The key feature of these surface designs is their lack of reliance on biomolecular fragments for specificity, focusing entirely on physicochemical principles at the lengthscales from 1 - 100 nm. This, along with a lack of formal patterning, provides the advantages of simplicity and cost effectiveness. This PhD thesis demonstrates these principles using a system in which cationic poly-L-lysine (PLL) patches (10 nm) are deposited randomly on a silica substrate and the remaining surface is passivated with a bio-compatible PEG brush. TIRF microscopy revealed that the patches were randomly arranged, not clustered. By precisely controlling the number of patches per unit area, the interfaces provide sharp selectivity for adhesion of proteins and bacterial cells. For instance, it was found that a critical density of patches (on the order of 1000/mum 2) was required for fibrinogen adsorption while a greater density comprised the adhesion threshold for albumin. Surface compositions between these two thresholds discriminated binding of the two proteins. The binding behavior of the two proteins from a mixture was well anticipated by the single- protein binding behaviors of the individual proteins. The mechanism for protein capture was shown to be multivalent: protein adhesion always occurred for averages spacings of the adhesive patches smaller than the dimensions of the protein of interest. For some backfill brush architectures, the spacing between the patches at the threshold for protein capture clearly corresponded to the major dimension of the target protein. For more dense PEG brush backfills however, larger adhesion thresholds were observed, corresponding to greater numbers of patches involved with the adhesion of each protein molecule. . The thesis demonstrates the tuning of the position of the adhesion thresholds, using fibrinogen as a model protein, using variations in brush properties and ionic strength. The directions of the trends indicate that the brushes do indeed exert steric repulsions toward the proteins while the attractions are electrostatic in nature. The surfaces also demonstrated sharp adhesion thresholds for S. Aureus bacteria, at smaller concentrations of adhesive surfaces elements than those needed for the protein capture. The results suggest that bacteria may be captured while proteins are rejected from these surfaces, and there may be potential to discriminate different bacterial types. Such discrimination from protein-containing bacterial suspensions was investigated briefly in this thesis using S. Aureus and fibrinogen as a model mixture. However, due to binding of fibrinogen to the bacterial surface, the separation did not succeed. It is still expected, however, that these surfaces could be used to selectively capture bacteria in the presence of non-interacting proteins. The interaction of these brushes with two different cationic species PLL and lysozyme were studied. The

  8. Desmoplakin is involved in organization of an adhesion complex in peripheral nerve regeneration after injury.

    PubMed

    Gess, B; Röhr, D; Lange, E; Halfter, H; Young, P

    2015-02-01

    Peripheral nerves have the unique capability to regenerate after injury. Insights into regeneration of peripheral nerves after injury may have implications for neurodegenerative diseases of the nervous system. In this study, we analyzed the expression and function of desmoplakin in peripheral nerve regeneration. Desmoplakin was upregulated in spinal cord motoneurons after sciatic nerve injury. Conditional ablation of desmoplakin in motoneurons demonstrated that desmoplakin is necessary for normal motor regeneration. SiRNA and desmoplakin deletion-constructs revealed a role of desmoplakin in neurite extension in vitro. A complex of N-cadherin, plakoglobin, desmoplakin and vimentin was shown in motoneuronal cell cultures and peripheral nerves after injury in vivo. Motor nerve fiber regeneration and localization of N-cadherin and vimentin to axonal growth fronts were reduced in conditionally desmoplakin-ablated mice. These data indicate a function of desmoplakin in motor nerve regeneration by linking N-cadherin to intermediate filaments in regenerating motor axons. PMID:25496840

  9. Recombinant Human Interferon-inducible Protein 10 Is a Chemoattractant for Human Monocytes and T Lymphocytes and Promotes T Cell Adhesion to Endothelial Cells

    Microsoft Academic Search

    Dennis D. Taub; Andrew R. Lloyd; Kevin Conlon; Ji Ming Wang; John R. Ortaldo; Akihisha Harada; Kouji Matsushima; David J. Kelvin; Joost J. Oppenheim

    Summary The human cytokine interferon-inducible protein 10 (IP-10) is a small glycoprotein secreted by activated T cells, monocytes, endothelial cells, and keratinocytes, and is structurally related to a family of chemotactic cytokines called chemokines. Although this protein is present in sites of delayed-type hypersensitivity reactions and lepromatous leprosy lesions, the biological activity of IP-10 remains unknown. We report here that

  10. Adhesive Contact Sweeper

    NASA Technical Reports Server (NTRS)

    Patterson, Jonathan D.

    1993-01-01

    Adhesive contact sweeper removes hair and particles vacuum cleaner leaves behind, without stirring up dust. Also cleans loose rugs. Sweeper holds commercially available spools of inverted adhesive tape. Suitable for use in environments in which air kept free of dust; optics laboratories, computer rooms, and areas inhabited by people allergic to dust. For carpets, best used in tandem with vacuum cleaner; first pass with vacuum cleaner removes coarse particles, and second pass with sweeper extracts fine particles. This practice extends useful life of adhesive spools.

  11. Stuck on You: Adhesion

    NSDL National Science Digital Library

    New Jersey

    2006-01-01

    Learners explore water adhesion and learn about why water molecules are more strongly attracted to some substances than others. In an investigation titled "Fabric Frenzy," learners use a magnifying glass to examine different fabrics and hypothesize whether each kind would be good for soaking up water. Learners then weigh the dry fabrics, predict how water will affect the weight of each sample, wet the samples, and weigh them again to see how much water they in fact absorb. Learners also examine other liquids and compare their adhesion to water adhesion.

  12. Large molecules as anti-adhesive compounds against pathogens.

    PubMed

    Wittschier, N; Lengsfeld, C; Vorthems, S; Stratmann, U; Ernst, J F; Verspohl, E J; Hensel, A

    2007-06-01

    Anti-adhesive compounds are potential prophylactic tools in alternative treatment regimes against bacterial infection, as bacterial adhesion is commonly mediated by carbohydrate-protein interactions between surface adhesions of microorganisms and the host cell. The use of exogenous polyvalent, high-molecular carbohydrates and tannin-like plant-derived compounds should antagonize the adhesive interaction. A range of carbohydrates and carbohydrate- and proanthocyanidin-enriched plant extracts were screened for potential anti-adhesive effects against Helicobacter pylori, Campylobacter jejuni, Porphyromonas gingivalis and Candida albicans in different in-situ assays on primary tissue. The adhesion of H. pylori on human stomach tissue was effectively blocked by glucuronic acid-enriched polysaccharides from immature okra fruits (Abelmoschus esculentus). These compounds also had strong in-vitro effects against C. jejuni (inhibition up to 80%), but were ineffective in an in-vivo study in infected chicken broilers due to metabolism in the gastrointestinal system. Polysaccharides from Glycyrrhizia glabra, also enriched with glucuronic acid, showed strong anti-adhesive properties against H. pylori and P. gingivalis (inhibition 60-70%). Pelargonium sidoides extract, containing mainly polymeric proanthocyanidins, was effective against H. pylori in a dose-dependent manner. Due to the multifunctional adhesive strategy of C. albicans, no effective compounds were detected against this yeast. Structure-activity relationships are presented and the potential in-vivo use of carbohydrate-based anti-adhesives is discussed. PMID:17637170

  13. Liprin-? is required for photoreceptor target selection in Drosophila

    PubMed Central

    Choe, Kwang-Min; Prakash, Saurabh; Bright, Ali; Clandinin, Thomas R.

    2006-01-01

    Classical cadherin-mediated interactions between axons and dendrites are critical to target selection and synapse assembly. However, the molecular mechanisms by which these interactions are controlled are incompletely understood. In the Drosophila visual system, N-cadherin is required in both photoreceptor (R cell) axons and their targets to mediate stabilizing interactions required for R cell target selection. Here we identify the scaffolding protein Liprin-? as a critical component in this process. We isolated mutations in Liprin-? in a genetic screen for mutations affecting the pattern of synaptic connections made by R1–R6 photoreceptors. Using eye-specific mosaics, we demonstrate a previously undescribed, axonal function for Liprin-? in target selection: Liprin-? is required to be cell-autonomous in all subtypes of R1–R6 cells for their axons to reach their targets. Because Liprin-?, the receptor tyrosine phosphatase LAR, and N-cadherin share qualitatively similar mutant phenotypes in R1–R6 cells and are coexpressed in R cells and their synaptic targets, we infer that these three genes act at the same step in the targeting process. However, unlike N-cadherin, neither Liprin-? nor LAR is required postsynaptically for R cells to project to their correct targets. Thus, these two proteins, unlike N-cadherin, are functionally asymmetric between axons and dendrites. We propose that the adhesive mechanisms that link pre- and postsynaptic cells before synapse formation may be differentially regulated in these two compartments. PMID:16864799

  14. Adhesion of Lunar Dust

    NASA Astrophysics Data System (ADS)

    Walton, Otis R.

    2007-04-01

    This paper reviews the physical characteristics of lunar dust and the effects of various fundamental forces acting on dust particles on surfaces in a lunar environment. There are transport forces and adhesion forces after contact. Mechanical forces (i.e., from rover wheels, astronaut boots and rocket engine blast) and static electric effects (from UV photo-ionization and/or tribo-electric charging) are likely to be the major contributors to the transport of dust particles. If fine regolith particles are deposited on a surface, then surface energy-related (e.g., van der Walls) adhesion forces and static-electric-image forces are likely to be the strongest contributors to adhesion. Some measurement techniques are offered to quantify the strength of adhesion forces. And finally some dust removal techniques are discussed.

  15. Adhesion of Lunar Dust

    NASA Technical Reports Server (NTRS)

    Walton, Otis R.

    2007-01-01

    This paper reviews the physical characteristics of lunar dust and the effects of various fundamental forces acting on dust particles on surfaces in a lunar environment. There are transport forces and adhesion forces after contact. Mechanical forces (i.e., from rover wheels, astronaut boots and rocket engine blast) and static electric effects (from UV photo-ionization and/or tribo-electric charging) are likely to be the major contributors to the transport of dust particles. If fine regolith particles are deposited on a surface, then surface energy-related (e.g., van der Walls) adhesion forces and static-electric-image forces are likely to be the strongest contributors to adhesion. Some measurement techniques are offered to quantify the strength of adhesion forces. And finally some dust removal techniques are discussed.

  16. Cell Substratum Adhesion during Early Development of Dictyostelium discoideum

    PubMed Central

    Tarantola, Marco; Bae, Albert; Fuller, Danny; Bodenschatz, Eberhard; Rappel, Wouter-Jan; Loomis, William F.

    2014-01-01

    Vegetative and developed amoebae of Dictyostelium discoideum gain traction and move rapidly on a wide range of substrata without forming focal adhesions. We used two independent assays to quantify cell-substrate adhesion in mutants and in wild-type cells as a function of development. Using a microfluidic device that generates a range of hydrodynamic shear stress, we found that substratum adhesion decreases at least 10 fold during the first 6 hr of development of wild type cells. This result was confirmed using a single-cell assay in which cells were attached to the cantilever of an atomic force probe and allowed to adhere to untreated glass surfaces before being retracted. Both of these assays showed that the decrease in substratum adhesion was dependent on the cAMP receptor CAR1 which triggers development. Vegetative cells missing talin as the result of a mutation in talA exhibited slightly reduced adhesive properties compared to vegetative wild-type cells. In sharp contrast to wild-type cells, however, these talA mutant cells did not show further reduction of adhesion during development such that after 5 hr of development they were significantly more adhesive than developed wild type cells. In addition, both assays showed that substrate adhesion was reduced in 0 hr cells when the actin cytoskeleton was disrupted by latrunculin. Consistent with previous observations, substrate adhesion was also reduced in 0 hr cells lacking the membrane proteins SadA or SibA as the result of mutations in sadA or sibA. However, there was no difference in the adhesion properties between wild type AX3 cells and these mutant cells after 6 hr of development, suggesting that neither SibA nor SadA play an essential role in substratum adhesion during aggregation. Our results provide a quantitative framework for further studies of cell substratum adhesion in Dictyostelium. PMID:25247557

  17. Cell substratum adhesion during early development of Dictyostelium discoideum.

    PubMed

    Tarantola, Marco; Bae, Albert; Fuller, Danny; Bodenschatz, Eberhard; Rappel, Wouter-Jan; Loomis, William F

    2014-01-01

    Vegetative and developed amoebae of Dictyostelium discoideum gain traction and move rapidly on a wide range of substrata without forming focal adhesions. We used two independent assays to quantify cell-substrate adhesion in mutants and in wild-type cells as a function of development. Using a microfluidic device that generates a range of hydrodynamic shear stress, we found that substratum adhesion decreases at least 10 fold during the first 6 hr of development of wild type cells. This result was confirmed using a single-cell assay in which cells were attached to the cantilever of an atomic force probe and allowed to adhere to untreated glass surfaces before being retracted. Both of these assays showed that the decrease in substratum adhesion was dependent on the cAMP receptor CAR1 which triggers development. Vegetative cells missing talin as the result of a mutation in talA exhibited slightly reduced adhesive properties compared to vegetative wild-type cells. In sharp contrast to wild-type cells, however, these talA mutant cells did not show further reduction of adhesion during development such that after 5 hr of development they were significantly more adhesive than developed wild type cells. In addition, both assays showed that substrate adhesion was reduced in 0 hr cells when the actin cytoskeleton was disrupted by latrunculin. Consistent with previous observations, substrate adhesion was also reduced in 0 hr cells lacking the membrane proteins SadA or SibA as the result of mutations in sadA or sibA. However, there was no difference in the adhesion properties between wild type AX3 cells and these mutant cells after 6 hr of development, suggesting that neither SibA nor SadA play an essential role in substratum adhesion during aggregation. Our results provide a quantitative framework for further studies of cell substratum adhesion in Dictyostelium. PMID:25247557

  18. Analysis of the Behaviours Mediating Barnacle Cyprid Reversible Adhesion

    PubMed Central

    Aldred, Nick; Høeg, Jens T.; Maruzzo, Diego; Clare, Anthony S.

    2013-01-01

    When exploring immersed surfaces the cypris larvae of barnacles employ a tenacious and rapidly reversible adhesion mechanism to facilitate their characteristic ‘walking’ behaviour. Although of direct relevance to the fields of marine biofouling and bio-inspired adhesive development, the mechanism of temporary adhesion in cyprids remains poorly understood. Cyprids secrete deposits of a proteinaceous substance during surface attachment and these are often visible as ‘footprints’ on previously explored surfaces. The attachment structures, the antennular discs, of cyprids also present a complex morphology reminiscent of both the hairy appendages used by some terrestrial invertebrates for temporary adhesion and a classic ‘suction cup’. Despite the numerous analytical approaches so-far employed, it has not been possible to resolve conclusively the respective contributions of viscoelastic adhesion via the proteinaceous ‘temporary adhesive’, ‘dry’ adhesion via the cuticular villi present on the disc and the behavioural contribution by the organism. In this study, high-speed photography was used for the first time to capture the behaviour of cyprids at the instant of temporary attachment and detachment. Attachment is facilitated by a constantly sticky disc surface – presumably due to the presence of the proteinaceous temporary adhesive. The tenacity of the resulting bond, however, is mediated behaviourally. For weak attachment the disc is constantly moved on the surface, whereas for a strong attachment the disc is spread out on the surface. Voluntary detachment is by force, requiring twisting or peeling of the bond – seemingly without any more subtle detachment behaviours. Micro-bubbles were observed at the adhesive interface as the cyprid detached, possibly an adaptation for energy dissipation. These observations will allow future work to focus more specifically on the cyprid temporary adhesive proteins, which appear to be fundamental to adhesion, inherently sticky and exquisitely adapted for reversible adhesion underwater. PMID:23874504

  19. Irrigant divalent cation concentrations influence bacterial adhesion

    PubMed Central

    Dass, Clarissa L.; Walsh, Mary F.; Seo, Sue; Shiratsuchi, Hiroe; Craig, David H.; Basson, Marc D.

    2009-01-01

    Background Surgical wounds are frequently contaminated by microbes, but rarely become infected if the bacterial burden is low, and irrigation is used to reduce contamination. Wound fluids are low in calcium and high in magnesium. We hypothesized that manipulating irrigant divalent cation concentrations might influence bacterial adhesion. Methods Staphylococcus aureus, E. coli, and Pseudomonas aeruginosa were stained with fluorescent Calcein AM before plating onto fibroblast monolayers, collagen I, or uncoated bacteriologic plastic. After one hour, wells were washed with HEPES-buffered pH-balanced sterile water without or with 5mM CaCl2, 5mM MgCl2 or 1mM EDTA+EGTA, and the remaining adherent bacteria were assayed fluorometrically. Results Supplementing the irrigation with magnesium or chelators increased but calcium-supplemented irrigation reduced bacterial adhesion to collagen or fibroblasts. Non-specific electrostatic bacterial adhesion to uncoated plastic was unaffected by calcium. Conclusion Bacterial adhesion to mammalian cells and matrix proteins is influenced by divalent cations, and pathogenic bacteria may be adapted to adhere under the low calcium high magnesium conditions in wounds. Although these results await confirmation for other bacteria, and in vivo validation and safety-testing, they suggest that supplementing wound irrigation with 5mM CaCl2 may reduce bacterial adhesion and subsequent wound infection. PMID:19577252

  20. Activity and Distribution of Paxillin, Focal Adhesion Kinase, and Cadherin Indicate Cooperative Roles during Zebrafish Morphogenesis

    Microsoft Academic Search

    Bryan D. Crawford; Clarissa A. Henry; Todd A. Clason; Amanda L. Becker; Merrill B. Hille

    2003-01-01

    We investigated the focal adhesion proteins paxillin and Fak, and the cell-cell adhesion protein cadherin in developing zebrafish (Danio rerio) embryos. Cadherins are expressed in presomitic mesoderm where they delineate cells. The initiation of somite formation coincides with an increase in the phosphorylation of Fak, and the accumulation of Fak, phosphorylated Fak, paxillin, and fibronectin at nascent somite boundaries. In

  1. The Glycosylphosphatidyl Inositol-anchored Adhesion Molecule F3\\/Contactin Is Required for Surface Transport of Paranodin\\/Contactin-associated Protein (caspr)

    Microsoft Academic Search

    Catherine Faivre-Sarrailh; France Gauthier; Natalia Denisenko-Nehrbass; André Le Bivic; Geneviève Rougon; Jean-Antoine Girault

    2000-01-01

    Paranodin\\/contactin-associated protein (caspr) is a transmembrane glycoprotein of the neur- exin superfamily that is highly enriched in the parano- dal regions of myelinated axons. We have investigated the role of its association with F3\\/contactin, a glyco- sylphosphatidyl inositol (GPI)-anchored neuronal ad- hesion molecule of the Ig superfamily. Paranodin was not expressed at the cell surface when transfected alone in CHO

  2. Diagnosis of late onset neonatal sepsis with cytokines, adhesion molecule, and C-reactive protein in preterm very low birthweight infants

    Microsoft Academic Search

    P C Ng; S H Cheng; K M Chui; T F Fok; M Y Wong; W Wong; R P O Wong; K L Cheung

    1997-01-01

    AIMSTo evaluate the commonly used markers—namely IL-6, TNF?, IL-1?, C-reactive protein and E-selectin for identification of late onset neonatal sepsis; to define the optimal cutoff value for each marker in preterm neonates; to assess whether these markers could assist in early discontinuation of antibiotics in non-infected cases; and to delineate the profile of these markers during systemic infection and in

  3. Combinatorial Investigations of Polymer Adhesion

    NSDL National Science Digital Library

    Crosby, Alfred

    2001-01-01

    In this work, we introduce a combinatorial technique that can be used to investigate adhesive interactions between a polymer and either another polymer, a ceramic, or a metal. The primary goal in the development of this technique is to design a high-throughput, parallel processing adhesion test that allows the adhesive strength dependence on multivariable environments to be determined. This combinatorial polymer adhesion test will provide qualitative and quantitative data used to determine absolute measures of adhesion as a function of the multidimensional parameter space. These results will aid industrial screening for optimal adhesives, as well as provide a unique tool for gaining a fundamental understanding of polymer adhesion. We investigate the temperature and thickness dependence of the self-adhesion of polystyrene (PS) and the adhesion between PS and poly(dimethylsiloxane) (PDMS) for demonstration of concept.

  4. Adhesion properties of potentially probiotic Lactobacillus kefiri to gastrointestinal mucus.

    PubMed

    Carasi, Paula; Ambrosis, Nicolás M; De Antoni, Graciela L; Bressollier, Philippe; Urdaci, María C; Serradell, María de los Angeles

    2014-02-01

    We investigated the mucus-binding properties of aggregating and non-aggregating potentially probiotic strains of kefir-isolated Lactobacillus kefiri, using different substrates. All the strains were able to adhere to commercial gastric mucin (MUCIN) and extracted mucus from small intestine (SIM) and colon (CM). The extraction of surface proteins from bacteria using LiCl or NaOH significantly reduced the adhesion of three selected strains (CIDCA 8348, CIDCA 83115 and JCM 5818); although a significant proportion (up to 50%) of S-layer proteins were not completely eliminated after treatments. The surface (S-layer) protein extracts from all the strains of Lb. kefiri were capable of binding to MUCIN, SIM or CM, and no differences were observed among them. The addition of their own surface protein extract increased adhesion of CIDCA 8348 and 83115 to MUCIN and SIM, meanwhile no changes in adhesion were observed for JCM 5818. None of the seven sugars tested had the ability to inhibit the adhesion of whole bacteria to the three mucus extracts. Noteworthy, the degree of bacterial adhesion reached in the presence of their own surface protein (S-layer) extract decreased to basal levels in the presence of some sugars, suggesting an interaction between the added sugar and the surface proteins. In conclusion, the ability of these food-isolated bacteria to adhere to gastrointestinal mucus becomes an essential issue regarding the biotechnological potentiality of Lb. kefiri for the food industry. PMID:24168928

  5. Regulation of Cell Adhesion Strength by Peripheral Focal Adhesion Distribution

    PubMed Central

    Elineni, Kranthi Kumar; Gallant, Nathan D.

    2011-01-01

    Cell adhesion to extracellular matrices is a tightly regulated process that involves the complex interplay between biochemical and mechanical events at the cell-adhesive interface. Previous work established the spatiotemporal contributions of adhesive components to adhesion strength and identified a nonlinear dependence on cell spreading. This study was designed to investigate the regulation of cell-adhesion strength by the size and position of focal adhesions (FA). The cell-adhesive interface was engineered to direct FA assembly to the periphery of the cell-spreading area to delineate the cell-adhesive area from the cell-spreading area. It was observed that redistributing the same adhesive area over a larger cell-spreading area significantly enhanced cell-adhesion strength, but only up to a threshold area. Moreover, the size of the peripheral FAs, which was interpreted as an adhesive patch, did not directly govern the adhesion strength. Interestingly, this is in contrast to the previously reported functional role of FAs in regulating cellular traction where sizes of the peripheral FAs play a critical role. These findings demonstrate, to our knowledge for the first time, that two spatial regimes in cell-spreading area exist that uniquely govern the structure-function role of FAs in regulating cell-adhesion strength. PMID:22208188

  6. C23 protein meditates bone morphogenetic protein-2-mediated EMT via up-regulation of Erk1/2 and Akt in gastric cancer.

    PubMed

    Yang, Yonggang; Yang, Chunyan; Zhang, Jianping

    2015-03-01

    In our previous study, the epithelial-to-mesenchymal transition (EMT) has been identified to be involved in gastric cancer progression. Notably, nuclear protein C23 and bone morphogenetic protein-2 (BMP2) have been linked into EMT. However, the specific mechanisms underlying BMP2 pathway-mediated EMT are not still unraveled. In this study, we adopted immunohistochemistry and immunoblotting to determine the expression of C23 and BMP2 receptor II (BMPR-II) in 90 gastric cancer samples and cell lines. Subsequently, relevant cell lines were selected to be treated with si-C23 or si-BMPRII and the detection of in vitro assay. Our results revealed that both C23 and BMPRII were aberrantly and constitutively expressed in gastric cancer specimens and cell lines, whose expression was positively associated with metastasis, stage and differentiation, and portended poor survival outcome of gastric cancer patients. In vitro assay validated the increased expression of p-Erk1/2, p-Akt, vimentin, N-cadherin, and MMP2 in BMP2-stimulated MGC803 cells, which was in a dose-dependent manner. By contrast, si-C23 treatment attenuated the BMP2-stimulated expression of p-Erk1/2, p-Akt, vimentin, N-cadherin, and MMP2. Also, the treatment of either si-C23 or si-BMPRII decreased the ability of migration and invasion of MGC803 cells. In conclusion, C23 mediates BMP2-induced EMT progression via the up-regulation of Erk1/2 and Akt signaling pathway in gastric cancer, which indicated both C23 and BMPRII pathway could be recommended as prospective targets or biomarkers to antagonize the progression of gastric cancer. PMID:25698539

  7. Platelet Adhesion under Flow

    PubMed Central

    Ruggeri, Zaverio M.

    2011-01-01

    Platelet adhesive mechanisms play a well-defined role in hemostasis and thrombosis, but evidence continues to emerge for a relevant contribution to other pathophysiological processes including inflammation, immune-mediated responses to microbial and viral pathogens, and cancer metastasis. Hemostasis and thrombosis are related aspects of the response to vascular injury, but the former protects from bleeding after trauma while the latter is a disease mechanism. In either situation, adhesive interactions mediated by specific membrane receptors support the initial attachment of single platelets to cellular and extracellular matrix constituents of the vessel wall and tissues. In the subsequent steps of thrombus growth and stabilization, adhesive interactions mediate platelet to platelet cohesion (aggregation) and anchoring to the fibrin clot. A key functional aspect of platelets is their ability to circulate in a quiescent state surveying the integrity of the inner vascular surface, coupled to a prompt reaction wherever alterations are detected. In many respects, therefore, platelet adhesion to vascular wall structures, to one another or to other blood cells are facets of the same fundamental biological process. The adaptation of platelet adhesive functions to the effects of blood flow is the main focus of this review. PMID:19191170

  8. Adiponectin Enhances Intercellular Adhesion Molecule-1 Expression and Promotes Monocyte Adhesion in Human Synovial Fibroblasts

    PubMed Central

    Chen, Hsien-Te; Tsou, Hsi-Kai; Chen, Jui-Chieh; Shih, James Meng-Kun; Chen, Yen-Jen; Tang, Chih-Hsin

    2014-01-01

    Adiponectin is a protein hormone secreted predominantly by differentiated adipocytes and is involved in energy homeostasis. Adiponectin expression is significantly high in the synovial fluid of patients with osteoarthritis (OA). Intercellular adhesion molecule-1 (ICAM-1) is an important adhesion molecule that mediates monocyte adhesion and infiltration during OA pathogenesis. Adiponectin-induced expression of ICAM-1 in human OA synovial fibroblasts (OASFs) was examined by using qPCR, flow cytometry and western blotting. The intracellular signaling pathways were investigated by pretreated with inhibitors or transfection with siRNA. The monocyte THP-1 cell line was used for an adhesion assay with OASFs. Stimulation of OASFs with adiponectin induced ICAM-1 expression. Pretreatment with AMP-activated protein kinase (AMPK) inhibitors (AraA and compound C) or transfection with siRNA against AMPK?1 and two AMPK upstream activator- liver kinase B1 (LKB1) and calmodulin-dependent protein kinase II (CaMKII) diminished the adiponectin-induced ICAM-1 expression. Stimulation of OASFs with adiponectin increased phosphorylation of LKB1, CaMKII, AMPK, and c-Jun, resulting in c-Jun binding to AP-1 element of ICAM-1 promoter. In addition, adiponectin-induced activation of the LKB1/CaMKII, AMPK, and AP-1 pathway increased the adhesion of monocytes to the OASF monolayer. Our results suggest that adiponectin increases ICAM-1 expression in human OASFs via the LKB1/CaMKII, AMPK, c-Jun, and AP-1 signaling pathway. Adiponectin-induced ICAM-1 expression promoted the adhesion of monocytes to human OASFs. These findings may provide a better understanding of the pathogenesis of OA and can utilize this knowledge to design a new therapeutic strategy. PMID:24667577

  9. Surfactant and adhesive formulations from alkaline biomass extracts

    NASA Astrophysics Data System (ADS)

    Baxter, Matthew

    This work studies the ability to produce effective surfactant and adhesive formulations using surface active biological material extracted from different biomass sources using alkaline extraction methods. Two urban waste biomass sources were used to produce surfactants, Return Activated Sludge (RAS), and solid Urban Refuse (UR). The third biomass source investigated was isolated mustard protein (MP). RAS and MP extracts were investigated for adhesive production. The results indicate that extracts from the waste biomass sources, RAS and UR, can be combined with a commercial surfactant, sodium dioctyl sulfosuccinate (AOT), to produce surfactants with low interfacial tensions against various oils. These highly surface-active formulations were shown to be useful in the removal of bitumen from contaminated sand. RAS and MP showed potential as protein-based wood adhesives. These sources were used in adhesive formulations to produce a strong bond strength under low-pressure, ambient pressing conditions.

  10. Redox regulation of cell migration and adhesion

    PubMed Central

    Hurd, Thomas Ryan; DeGennaro, Matthew; Lehmann, Ruth

    2015-01-01

    Reactive oxygen species (ROS), particularly hydrogen peroxide, and the proteins that regulate them play important roles in the migration and adhesion of cells. Stimulation of cell surface receptors with growth factors and chemoattractants generates ROS, which relay signals from the cell surface to key signaling proteins inside the cell. ROS act within cells to promote migration and also in nonmigrating cells to influence the behavior of migrating cells. Hydrogen peroxide has also been suggested to act as a chemoattractant in its own right, drawing immune cells to wounds. We discuss recent progress made towards understanding how organisms use ROS, and to what degree they depend on them, during the related processes of cell migration and adhesion. PMID:22209517

  11. Osteoactivin promotes osteoblast adhesion through HSPG and ?v?1 integrin.

    PubMed

    Moussa, Fouad M; Hisijara, Israel Arango; Sondag, Gregory R; Scott, Ethan M; Frara, Nagat; Abdelmagid, Samir M; Safadi, Fayez F

    2014-07-01

    Osteoactivin (OA), also known as glycoprotein nmb (gpnmb) plays an important role in the regulation of osteoblast differentiation and function. OA induced osteoblast differentiation and function in vitro by stimulating alkaline phosphatase (ALP) activity, osteocalcin production, nodule formation, and matrix mineralization. Recent studies reported a role for OA in cell adhesion and integrin binding. In this study, we demonstrate that recombinant osteoactivin (rOA) as a matricellular protein stimulated adhesion, spreading and differentiation of MC3T3-E1 osteoblast-like cells through binding to ?v ?1 integrin and heparan sulfated proteoglycans (HSPGs). MC3T3-E1 cell adhesion to rOA was blocked by neutralizing anti-OA or anti-?v and ?1 integrin antibodies. rOA stimulated-osteoblast adhesion was also inhibited by soluble heparin and sodium chlorate. Interestingly, rOA stimulated-osteoblast adhesion promoted an increase in FAK and ERK activation, resulting in the formation of focal adhesions, cell spreading and enhanced actin cytoskeleton organization. In addition, differentiation of primary osteoblasts was augmented on rOA coated-wells marked by increased alkaline phosphatase staining and activity. Taken together, these data implicate OA as a matricellular protein that stimulates osteoblast adhesion through binding to ?v ?1 integrin and cell surface HSPGs, resulting in increased cell spreading, actin reorganization, and osteoblast differentiation with emphasis on the positive role of OA in osteogenesis. PMID:24415158

  12. Transforming growth factor-?3 regulates cell junction restructuring via MAPK-mediated mRNA destabilization and Smad-dependent protein degradation of junctional adhesion molecule B (JAM-B).

    PubMed

    Zhang, Xu; Lui, Wing-Yee

    2015-06-01

    Junctional adhesion molecule-B (JAM-B) is found between Sertoli cells at the blood-testis barrier (BTB) as well as between Sertoli and germ cells at the apical ectoplasmic specializations (ES) in the testis. The expression of JAM-B is tightly regulated to modulate the passage of spermatocytes across the BTB as well as the release of mature spermatozoa from the seminiferous epithelium. Transforming growth factor beta (TGF-?) family is implicated in the regulation of testicular cell junction dynamics during spermatogenesis. This study aims to investigate the effects of TGF-?3 on the expression of JAM-B as well as the underlying mechanisms on how TGF-?3 regulates JAM-B expression to facilitate the disassembly of the BTB and apical ES. Our results revealed that TGF-?3 suppresses JAM-B at post-transcriptional and post-translational levels. Inhibitor, siRNA knockdown and co-immunoprecipitation have shown that TGF-?3 induces JAM-B protein degradation via ubiquitin-proteasome pathway. Immunofluorescence staining further confirmed that blockage of ubiquitin-proteasome pathway could abrogate TGF-?3-induced loss of JAM-B at the cell-cell interface. siRNA knockdown and immunofluorescence staining also demonstrated that activation of Smad signaling is required for TGF-?3-induced JAM-B protein degradation. In addition, TGF-?3 reduces JAM-B mRNA levels, at least in part, via post-transcriptional regulation. mRNA stability assay has confirmed that TGF-?3 promotes the degradation of JAM-B transcript and TGF-?3-mediated mRNA destabilization requires the activation of ERK1/2 and p54 JNK signal cascades. Taken together, TGF-?3 significantly downregulates JAM-B expression via post-transcriptional and post-translational modulation and results in the disruption of BTB and apical ES. PMID:25817991

  13. Identification of Sequences in the Polysialyltransferases ST8Sia II and ST8Sia IV That Are Required for the Protein-specific Polysialylation of the Neural Cell Adhesion Molecule, NCAM*

    PubMed Central

    Foley, Deirdre A.; Swartzentruber, Kristin G.; Colley, Karen J.

    2009-01-01

    The polysialyltransferases ST8Sia II and ST8Sia IV polysialylate the glycans of a small subset of mammalian proteins. Their most abundant substrate is the neural cell adhesion molecule (NCAM). An acidic surface patch and a novel ?-helix in the first fibronectin type III repeat of NCAM are required for the polysialylation of N-glycans on the adjacent immunoglobulin domain. Inspection of ST8Sia IV sequences revealed two conserved polybasic regions that might interact with the NCAM acidic patch or the growing polysialic acid chain. One is the previously identified polysialyltransferase domain (Nakata, D., Zhang, L., and Troy, F. A. (2006) Glycoconj. J. 23, 423–436). The second is a 35-amino acid polybasic region that contains seven basic residues and is equidistant from the large sialyl motif in both polysialyltransferases. We replaced these basic residues to evaluate their role in enzyme autopolysialylation and NCAM-specific polysialylation. We found that replacement of Arg276/Arg277 or Arg265 in the polysialyltransferase domain of ST8Sia IV decreased both NCAM polysialylation and autopolysialylation in parallel, suggesting that these residues are important for catalytic activity. In contrast, replacing Arg82/Arg93 in ST8Sia IV with alanine substantially decreased NCAM-specific polysialylation while only partially impacting autopolysialylation, suggesting that these residues may be particularly important for NCAM polysialylation. Two conserved negatively charged residues, Glu92 and Asp94, surround Arg93. Replacement of these residues with alanine largely inactivated ST8Sia IV, whereas reversing these residues enhanced enzyme autopolysialylation but significantly reduced NCAM polysialylation. In sum, we have identified selected amino acids in this conserved polysialyltransferase polybasic region that are critical for the protein-specific polysialylation of NCAM. PMID:19336400

  14. Adhesion in Nanodiamond Particles

    NASA Astrophysics Data System (ADS)

    Aravind, Vasudeva; Lutkus, Luke; Legum, Benjamin; Clarion Collaboration

    2013-03-01

    Due to their excellent mechanical properties and biologically non-toxic nature, nanodiamonds show great promise for applications in tribology, lubrication, drug delivery, tissue scaffolds and surgical implants. In order to design effective nanocomposites and other biomedical systems exploiting these properties, it is important to understand the properties and mechanisms by which nanodiamonds adhere to other materials, and how they behave at interfaces. In this article, the adhesive force between nanodiamond particles and the silicon scanning probe microscope tip are reported. The adhesive force can be correlated to the purity and functionalization of nanodiamond surface, and the values range from 0.1nN to 2.0nN for the samples studied. It is observed that the lateral forces applied by the scanning probe tip can cause the adhesive forces to increase by an order of magnitude from 0.1 to 2.0nN at regions where the tip experiences maximum contact force.

  15. Adhesive particle shielding

    DOEpatents

    Klebanoff, Leonard Elliott (Dublin, CA); Rader, Daniel John (Albuquerque, NM); Walton, Christopher (Berkeley, CA); Folta, James (Livermore, CA)

    2009-01-06

    An efficient device for capturing fast moving particles has an adhesive particle shield that includes (i) a mounting panel and (ii) a film that is attached to the mounting panel wherein the outer surface of the film has an adhesive coating disposed thereon to capture particles contacting the outer surface. The shield can be employed to maintain a substantially particle free environment such as in photolithographic systems having critical surfaces, such as wafers, masks, and optics and in the tools used to make these components, that are sensitive to particle contamination. The shield can be portable to be positioned in hard-to-reach areas of a photolithography machine. The adhesive particle shield can incorporate cooling means to attract particles via the thermophoresis effect.

  16. Isolation and Characterization of Adhesive Secretion from Cuvierian Tubules of Sea Cucumber Holothuria forskåli (Echinodermata: Holothuroidea)

    PubMed Central

    Baranowska, Malgorzata; Schloßmacher, Ute; McKenzie, J. Douglas; Müller, Werner E. G.; Schröder, Heinz C.

    2011-01-01

    The sea cucumber Holothuria forskåli possesses a specialized system called Cuvierian tubules. During mechanical stimulation white filaments (tubules) are expelled and become sticky upon contact with any object. We isolated a protein with adhesive properties from protein extracts of Cuvierian tubules from H. forskåli. This protein was identified by antibodies against recombinant precollagen D which is located in the byssal threads of the mussel Mytilus galloprovincialis. To find out the optimal procedure for extraction and purification, the identified protein was isolated by several methods, including electroelution, binding to glass beads, immunoprecipitation, and gel filtration. Antibodies raised against the isolated protein were used for localization of the adhesive protein in Cuvierian tubules. Immunostaining and immunogold electron microscopical studies revealed the strongest immunoreactivity in the mesothelium; this tissue layer is involved in adhesion. Adhesion of Cuvierian tubule extracts was measured on the surface of various materials. The extracted protein showed the strongest adhesion to Teflon surface. Increased adhesion was observed in the presence of potassium and EDTA, while cadmium caused a decrease in adhesion. Addition of antibodies and trypsin abolished the adhesive properties of the extract. PMID:22013488

  17. Switchable bio-inspired adhesives

    NASA Astrophysics Data System (ADS)

    Kroner, Elmar

    2015-03-01

    Geckos have astonishing climbing abilities. They can adhere to almost any surface and can run on walls and even stick to ceilings. The extraordinary adhesion performance is caused by a combination of a complex surface pattern on their toes and the biomechanics of its movement. These biological dry adhesives have been intensely investigated during recent years because of the unique combination of adhesive properties. They provide high adhesion, allow for easy detachment, can be removed residue-free, and have self-cleaning properties. Many aspects have been successfully mimicked, leading to artificial, bio-inspired, patterned dry adhesives, and were addressed and in some aspects they even outperform the adhesion capabilities of geckos. However, designing artificial patterned adhesion systems with switchable adhesion remains a big challenge; the gecko's adhesion system is based on a complex hierarchical surface structure and on advanced biomechanics, which are both difficult to mimic. In this paper, two approaches are presented to achieve switchable adhesion. The first approach is based on a patterned polydimethylsiloxane (PDMS) polymer, where adhesion can be switched on and off by applying a low and a high compressive preload. The switch in adhesion is caused by a reversible mechanical instability of the adhesive silicone structures. The second approach is based on a composite material consisting of a Nickel- Titanium (NiTi) shape memory alloy and a patterned adhesive PDMS layer. The NiTi alloy is trained to change its surface topography as a function of temperature, which results in a change of the contact area and of alignment of the adhesive pattern towards a substrate, leading to switchable adhesion. These examples show that the unique properties of bio-inspired adhesives can be greatly improved by new concepts such as mechanical instability or by the use of active materials which react to external stimuli.

  18. Chromosomal assignment of four testis-expressed mouse genes from a new family of transmembrane proteins (ADAMs) involved in cell-cell adhesion and fusion

    SciTech Connect

    Cho, Chunghee; Primakoff, P.; Myles, D.G. [Univ. of Connecticut Health Center, Farmington, CT (United States)] [and others] [Univ. of Connecticut Health Center, Farmington, CT (United States); and others

    1996-06-15

    A new gene family of mutidomain membrane proteins (ADAMs) that include A Disintegrin And Metalloprotease domain comprises an increasing number of identified members. Two members of this family, fertilin {alpha} and fertilin {beta}, form a heterodimeric protein that is required for sperm-egg fusion. Most recently, it has been shown that a third family member, meltrin {alpha}, is involved in myoblast fusion. Using restriction fragment length polymorphism analysis of a DNA panel from an interspecific backcross, we have determined the chromosomal locations of four mouse genes of this family that are expressed in testis: fertilin {alpha}, fertilin {beta}, ADAM 4, and ADAM 5. These genes have been given the locus symbols Ftna (fertilin {alpha}), FTnb (fertilin {beta}), Adam4 (ADAM 4), and Adam5 (ADAM 5). They were mapped to chromosomes 5, 14, 9, and 8, respectively, revealing a dispersed localization. Human chromosome locations of these genes are predicted on the basis of the mapping results using the information provided by comparative linkage maps. Because all four of these ADAM genes are expressed in testis and fertilin {alpha} and {beta} have been found to be important for fertilization, we compared their chromosomal locations with known mouse mutations affecting spermatogenesis and fertility. 17 refs., 1 fig., 1 tab.

  19. Statins inhibit high glucose-mediated neutrophil–endothelial cell adhesion through decreasing surface expression of endothelial adhesion molecules by stimulating production of endothelial nitric oxide

    Microsoft Academic Search

    Hitoshi Omi; Naotsuka Okayama; Manabu Shimizu; Tatsuya Fukutomi; Kenro Imaeda; Masahiro Okouchi; Makoto Itoh

    2003-01-01

    Neutrophil–endothelial adhesion is a crucial step in vascular inflammation, which is recognized as the direct cause of atherosclerosis-mediated serious diseases. We demonstrated previously that high glucose increased adhesion in a protein kinase C (PKC)-dependent manner within 48 h through increasing surface expression of endothelial adhesion molecules. On the other hand, statins, used for patients with hypercholesterolemia, have been shown to

  20. Elastomer toughened polyimide adhesives

    NASA Technical Reports Server (NTRS)

    St.clair, A. K.; St.clair, T. L. (inventors)

    1983-01-01

    A rubber-toughened addition-type polyimide composition is disclosed which has excellent high temperature bonding characteristics in the fully cured state, and improved peel strength and adhesive fracture resistance physical property characteristics. The process for making the improved adhesive involves preparing the rubber containing amic acid prepolymer by chemically reacting an amine-terminated elastomer and an aromatic diamine with an aromatic dianhydride with which a reactive chain stopper anhydride was mixed, and utilizing solvent or mixture of solvents for the reaction.

  1. Nectin: an adhesion molecule involved in formation of synapses

    Microsoft Academic Search

    Akira Mizoguchi; Hiroyuki Nakanishi; Kazushi Kimura; Kaho Matsubara; Kumi Ozaki-Kuroda; Tatsuo Katata; Tomoyuki Honda; Yoshimoto Kiyohara; Kyun Heo; Mikito Higashi; Tomonari Tsutsumi; Satomi Sonoda; Chizuka Ide; Yoshimi Takai

    2002-01-01

    he nectin-afadin system is a novel cell-cell adhesion system that organizes adherens junctions cooperatively with the cadherin-catenin system in epithelial cells. Nectin is an immunoglobulin-like adhesion molecule, and afadin is an actin filament-binding protein that connects nectin to the actin cytoskeleton. Nectin has four isoforms (-1, -2, -3, and -4). Each nectin forms a homo-cis-dimer followed by formation of a

  2. Bovine Serum Albumin (BSA) as an adhesive for wet cellulose

    Microsoft Academic Search

    Shunxing Su; Robert Pelton

    2006-01-01

    Regenerated cellulose films were laminated using very thin layers of the protein Bovine Serum Albumin (BSA) as an adhesive. The wet delamination strength was measured as functions of pH, lamination time, temperature and pressure, as well as cellulose oxidation. Drying at elevated temperature (120 °C) was required for strong adhesion. Oxidation of the cellulose membranes to introduce surface carboxyl\\/aldehyde groups increased

  3. Identification and comparison of residues critical for cell- adhesion activities of two neutrophil CD66 antigens, CEACAM6 and CEACAM8

    Microsoft Academic Search

    Motomu Kuroki; Hironori Abe; Takayuki Imakiirei; Shaoxi Liao; Hiroko Uchida; Yasushi Yamauchi; Shinzo Oikawa; Masahide Kuroki

    CEACAM6 (CD66c) and CEACAM8 (CD66b) are cell-adhesion proteins on neutrophils that belong to the human carcinoembryonic anti- gen (CEA) family. CEACAM6 reveals homophilic adhesion and heterophilic adhesion to other CEACAM family antigens including CEACAM8, CEACAM1, and CEA, whereas CEACAM8 exhibits only heterophilic adhesion to CEACAM6. Here, we investigated and compared structural require- ments for the homophilic adhesion of CEACAM6 and

  4. 3-D foam adhesive deposition

    NASA Technical Reports Server (NTRS)

    Lemons, C. R.; Salmassy, O. K.

    1976-01-01

    Bonding method, which reduces amount and weight of adhesive, is applicable to foam-filled honeycomb constructions. Novel features of process include temperature-viscosity control and removal of excess adhesive by transfer to cellophane film.

  5. Adhesive for cryogenic temperature applications

    NASA Technical Reports Server (NTRS)

    Doyle, H. M.

    1969-01-01

    Adhesive, which bonds a metal liner to a filament wound composite structure used for cryogenic pressure vessels, prevents the metal liner from buckling under depressurization. The adhesive consists of adducts of urethane and epoxy resins.

  6. AF6 negatively regulates Rap1-induced cell adhesion.

    PubMed

    Zhang, Zhongchun; Rehmann, Holger; Price, Leo S; Riedl, Jurgen; Bos, Johannes L

    2005-09-30

    AF6 is involved in the connection of membrane-associated proteins to the actin cytoskeleton. It binds to Ras-like small GTPases and is suggested to be an effector of both Ras and Rap. Here we show that knockdown of AF6 in T cells by RNA interference enhanced Rap1-induced integrin-mediated cell adhesion, whereas overexpression of AF6 had the opposite effect. Interestingly, AF6-induced inhibition of cell adhesion correlated with an increase in RapGTP levels. Like AF6, protein KIAA1849 contains a Ras association domain and interacted with Rap1. However, KIAA1849 did not inhibit Rap1-induced cell adhesion. We concluded that AF6 is a negative regulator of Rap-induced cell adhesion. We proposed that AF6 inhibits Rap-mediated cell adhesion by sequestering RapGTP in an unproductive complex and thus prevents the interaction of Rap1 not only with effectors that mediate adhesion but also with Rap GTPase-activating proteins. Thus, AF6 may buffer RapGTP in resting T cells and maintain them in a non-adherent state. PMID:16051602

  7. Adhesion of bifidobacteria to granular starch and its implications in probiotic technologies.

    PubMed

    Crittenden, R; Laitila, A; Forssell, P; Mättö, J; Saarela, M; Mattila-Sandholm, T; Myllärinen, P

    2001-08-01

    Adhesion of 19 Bifidobacterium strains to native maize, potato, oat, and barley starch granules was examined to investigate links between adhesion and substrate utilization and to determine if adhesion to starch could be exploited in probiotic food technologies. Starch adhesion was not characteristic of all the bifidobacteria tested. Adherent bacteria bound similarly to the different types of starch, and the binding capacity of the starch (number of bacteria per gram) correlated to the surface area of the granules. Highly adherent strains were able to hydrolyze the granular starches, but not all amylolytic strains were adherent, indicating that starch adhesion is not a prerequisite for efficient substrate utilization for all bifidobacteria. Adhesion was mediated by a cell surface protein(s). For the model organisms tested (Bifidobacterium adolescentis VTT E-001561 and Bifidobacterium pseudolongum ATCC 25526), adhesion appeared to be specific for alpha-1,4-linked glucose sugars, since adhesion was inhibited by maltose, maltodextrin, amylose, and soluble starch but not by trehalose, cellobiose, or lactose. In an in vitro gastric model, adhesion was inhibited both by the action of protease and at pH values of < or =3. Adhesion was not affected by bile, but the binding capacity of the starch was reduced by exposure to pancreatin. It may be possible to exploit adhesion of probiotic bifidobacteria to starch granules in microencapsulation technology and for synbiotic food applications. PMID:11472921

  8. Increasing throughput of AFM-based single cell adhesion measurements through multisubstrate surfaces.

    PubMed

    Yu, Miao; Strohmeyer, Nico; Wang, Jinghe; Müller, Daniel J; Helenius, Jonne

    2015-01-01

    Mammalian cells regulate adhesion by expressing and regulating a diverse array of cell adhesion molecules on their cell surfaces. Since different cell types express distinct sets of cell adhesion molecules, substrate-specific adhesion is cell type- and condition-dependent. Single-cell force spectroscopy is used to quantify the contribution of cell adhesion molecules to adhesion of cells to specific substrates at both the cell and single molecule level. However, the low throughput of single-cell adhesion experiments greatly limits the number of substrates that can be examined. In order to overcome this limitation, segmented polydimethylsiloxane (PDMS) masks were developed, allowing the measurement of cell adhesion to multiple substrates. To verify the utility of the masks, the adhesion of four different cell lines, HeLa (Kyoto), prostate cancer (PC), mouse kidney fibroblast and MDCK, to three extracellular matrix proteins, fibronectin, collagen I and laminin 332, was examined. The adhesion of each cell line to different matrix proteins was found to be distinct; no two cell lines adhered equally to each of the proteins. The PDMS masks improved the throughput limitation of single-cell force spectroscopy and allowed for experiments that previously were not feasible. Since the masks are economical and versatile, they can aid in the improvement of various assays. PMID:25671160

  9. Mechanisms of Adhesion in Geckos

    Microsoft Academic Search

    KELLAR AUTUMN; ANNE M. PEATTIE

    2002-01-01

    SYNOPSIS. The extraordinary adhesive capabilities of geckos have challenged explanation for millennia, since Aristotle first recorded his observations. We have discovered many of the secrets of gecko adhesion, yet the millions of dry, adhesive setae on the toes of geckos continue to generate puzzling new questions and valuable answers. Each epidermally-derived, keratinous seta ends in hundreds of 200 nm spatular

  10. Adhesion of explosives.

    PubMed

    Chaffee-Cipich, Michelle N; Sturtevant, Bryce D; Beaudoin, Stephen P

    2013-06-01

    It is of increasing importance to understand how explosive particles adhere to surfaces in order to understand how to remove them for detection in airport or other security settings. In this study, adhesion forces between royal demolition explosive (cyclotrimethylenetrinitramine) (RDX), pentaerythritol tetranitrate (PETN), and trinitrotoluene (TNT) in their crystalline forms and aluminum coupons with three finishes, acrylic melamine (clear coating), polyester acrylic melamine (white coating) automotive finishes, and a green military-grade finish, were measured and modeled. The force measurements were performed using the atomic force microscopy (AFM)-based colloidal probe microscopy (CPM) method. Explosive particles were mounted on AFM cantilevers and repeatedly brought in and out of contact with the surfaces of interest while the required force needed to pull out of contact was recorded. An existing Matlab-based simulator was used to describe the observed adhesion force distributions, with excellent agreement. In these simulations, the measured topographies of the interacting surfaces were considered, although the geometries were approximated. The simulations were performed using a van der Waals force-based adhesion model and a composite effective Hamaker constant. It was determined that certain combinations of roughness on the interacting surfaces led to preferred particle-substrate orientations that produced extreme adhesion forces. PMID:23510004

  11. Rapid adhesive bonding concepts

    NASA Technical Reports Server (NTRS)

    Stein, B. A.; Tyeryar, J. R.; Hodges, W. T.

    1984-01-01

    Adhesive bonding in the aerospace industry typically utilizes autoclaves or presses which have considerable thermal mass. As a consequence, the rates of heatup and cooldown of the bonded parts are limited and the total time and cost of the bonding process is often relatively high. Many of the adhesives themselves do not inherently require long processing times. Bonding could be performed rapidly if the heat was concentrated in the bond lines or at least in the adherends. Rapid adhesive bonding concepts were developed to utilize induction heating techniques to provide heat directly to the bond line and/or adherends without heating the entire structure, supports, and fixtures of a bonding assembly. Bonding times for specimens are cut by a factor of 10 to 100 compared to standard press bonding. The development of rapid adhesive bonding for lap shear specimens (per ASTM D1003 and D3163), for aerospace panel bonding, and for field repair needs of metallic and advanced fiber reinforced polymeric matrix composite structures are reviewed.

  12. Labial adhesion and bacteriuria

    PubMed Central

    Azarfar, Anoush; Ravanshad, Yalda; Bagheri, Sepideh; Esmaeeli, Mohammad; Nejad, Mahmood Malek

    2015-01-01

    Objective The purpose of this study is to evaluate the clinical presentation, laboratory findings, and response to treatment in girls with labial adhesion younger than 23 months. Material and Methods A retrospective chart review of all girls younger than 23 months with the diagnosis of labial adhesion was referred to Dr Sheikh children’s clinic in Mashhad in northeast Iran between 1998 and 2013. Results Sixty-three patients were diagnosed with labial adhesion during the review period. Most patients were diagnosed by physicians during the physical examination or during the evaluation for their voiding problems. The most prevalent symptom among patients was dysuria and restlessness while voiding. Twenty-one (33.3%) patients had a history of urinary tract infection. 17 (26.9%) patients had sterile pyuria and 69.8% showed presence of bacteria in their urine samples. Conclusion Physicians may frequently encounter pre-pubertal girls whose urinalysis may show sterile pyuria or presence of bacteria with colony counts <105 in the absence of urinary tract infection symptoms. In these cases, labial adhesion should always be suspected and genital examination should be performed. PMID:26097386

  13. A reversible wet/dry adhesive inspired by mussels and geckos.

    PubMed

    Lee, Haeshin; Lee, Bruce P; Messersmith, Phillip B

    2007-07-19

    The adhesive strategy of the gecko relies on foot pads composed of specialized keratinous foot-hairs called setae, which are subdivided into terminal spatulae of approximately 200 nm (ref. 1). Contact between the gecko foot and an opposing surface generates adhesive forces that are sufficient to allow the gecko to cling onto vertical and even inverted surfaces. Although strong, the adhesion is temporary, permitting rapid detachment and reattachment of the gecko foot during locomotion. Researchers have attempted to capture these properties of gecko adhesive in synthetic mimics with nanoscale surface features reminiscent of setae; however, maintenance of adhesive performance over many cycles has been elusive, and gecko adhesion is greatly diminished upon full immersion in water. Here we report a hybrid biologically inspired adhesive consisting of an array of nanofabricated polymer pillars coated with a thin layer of a synthetic polymer that mimics the wet adhesive proteins found in mussel holdfasts. Wet adhesion of the nanostructured polymer pillar arrays increased nearly 15-fold when coated with mussel-mimetic polymer. The system maintains its adhesive performance for over a thousand contact cycles in both dry and wet environments. This hybrid adhesive, which combines the salient design elements of both gecko and mussel adhesives, should be useful for reversible attachment to a variety of surfaces in any environment. PMID:17637666

  14. Adhesion of microvascular endothelial cells to metallic implant surfaces.

    PubMed

    Smith, R A; Mosesson, M W; Daniels, A U; Gartner, T K

    2000-05-01

    The objective of this study was to explore the molecular mechanisms of adhesion of endothelial cells (ECs) to implant grades of titanium alloy (Ti) and stainless steel (SS), compared to tissue culture polystyrene (PS). The idea is that promotion of EC adhesion to implant surfaces during the initial stages of healing may be critical in the formation of a capillary bed intimately associated with the implant surface. Ultimately this could be expected in turn to promote bone formation close to the surface and a more stable implant/bone interface. Surfaces were coated with either peak 1 fibrinogen gammaAgammaA, fibrinogen Fr I-9, fibrinogen fragment D1, fibronectin, vitronectin, or fetal calf serum and then post-coated with bovine serum albumin (BSA) to block non-specific cell adhesion. Surfaces with BSA alone and no other protein coating were also evaluated. Fibronectin coating maximized cell adhesion on all three surfaces, and adhesion was highest on PS. BSA blocked cell adhesion to PS (and most adhesion to SS) much better than to Ti. These results provide evidence that BSA adsorption on the metal surface is unable to effectively block the adhesion of the cells to the Ti. These data may provide a basis for understanding in vivo observations that soft tissue becomes attached to a Ti surface more rapidly and with more bone formation than to SS. Evidence is also presented that alphavbeta3 plays an important role in adhesion of ECs to the Ti surface. These experiments also provide preliminary data which may reflect some of the features of initial EC adhesion to metal implants. PMID:15348024

  15. Adhesion mechanics of ivy nanoparticles.

    PubMed

    Wu, Yu; Zhao, Xiaopeng; Zhang, Mingjun

    2010-04-15

    Adhesion mechanism of ivy has been of major research interest for its potential applications in high-strength materials. Recent experimental studies demonstrated that nanoparticles secreted from ivy tendrils play an important role in adhesion. In this work, we investigate how various factors such as van der Waals interaction, capillarity, and molecular cross-linking influence the adhesion mechanics of ivy nanoparticles. This paper provides guidelines in choosing different adhesive contact models. Understanding the mechanics of ivy adhesion could potentially inspire the design and fabrication of novel nano-bio-materials. PMID:20070973

  16. Biological adhesives and fastening devices

    NASA Astrophysics Data System (ADS)

    Wolpert, H. D.

    2012-04-01

    Sea creatures are a leading source to some of the more interesting discoveries in adhesives. Because sea water naturally breaks down even the strongest conventional adhesive, an alternative is important that could be used in repairing or fabricating anything that might have regular contact with moisture such as: Repairing broken and shattered bones, developing a surgical adhesive, use in the dental work, repairing and building ships, and manufacturing plywood. Some of nature's prototypes include the common mussel, limpet, some bacteria and abalone. As we learn more about these adhesives we are also developing non adhesive fasteners, such as mimicked after studying the octopus, burdock burrs (i.e. Velcro®) and the gecko.

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

    SciTech Connect

    Wu, C.-C. [Institute of Biomedical Engineering, National Cheng Kung University, Tainan, Taiwan (China); Su, H.-W. [Department of Physiology, National Cheng Kung University, Tainan, Taiwan (China); Lee, C.-C. [Institute of Biomedical Engineering, National Cheng Kung University, Tainan, Taiwan (China); Tang, M.-J. [Department of Physiology, National Cheng Kung University, Tainan, Taiwan (China); Su, F.-C. [Institute of Biomedical Engineering, National Cheng Kung University, Tainan, Taiwan (China)]. E-mail: fcsu@mail.ncku.edu.tw

    2005-04-01

    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 ({approx}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.

  18. Adhesion behaviors on superhydrophobic surfaces.

    PubMed

    Zhu, Huan; Guo, Zhiguang; Liu, Weimin

    2014-04-18

    The adhesion behaviors of superhydrophobic surfaces have become an emerging topic to researchers in various fields as a vital step in the interactions between materials and organisms/materials. Controlling the chemical compositions and topological structures via various methods or technologies is essential to fabricate and modulate different adhesion properties, such as low-adhesion, high-adhesion and anisotropic adhesion on superhydrophobic surfaces. We summarize the recent developments in both natural superhydrophobic surfaces and artificial superhydrophobic surfaces with various adhesions and also pay attention to superhydrophobic surfaces switching between low- and high-adhesion. The methods to regulate or translate the adhesion of superhydrophobic surfaces can be considered from two perspectives. One is to control the chemical composition and change the surface geometric structure on the surfaces, respectively or simultaneously. The other is to provide external stimulations to induce transitions, which is the most common method for obtaining switchable adhesions. Additionally, adhesion behaviors on solid-solid interfaces, such as the behaviors of cells, bacteria, biomolecules and icing on superhydrophobic surfaces are also noticeable and controversial. This review is aimed at giving a brief and crucial overview of adhesion behaviors on superhydrophobic surfaces. PMID:24575424

  19. Integrin adhesions: who's on first? What's on second? Connections between FAK and talin.

    PubMed

    Lawson, Christine; Schlaepfer, David D

    2012-01-01

    Cell migration requires the coordination of adhesion site assembly and turnover. Canonical models for nascent adhesion formation postulate that integrin binding to extracellular matrix (ECM) proteins results in the rapid recruitment of cytoskeletal proteins such as talin and paxillin to integrin cytoplasmic domains. It is thought that integrin-talin clusters recruit and activate tyrosine kinases such as focal adhesion kinase (FAK). However, the molecular connections of this linkage remain unresolved. Our recent findings support an alternative model whereby FAK recruits talin to new sites of ?1 integrin-mediated adhesion in mouse embryonic fibroblasts and human ovarian carcinoma cells. This is dependent on a direct binding interaction between FAK and talin and occurs independently of direct talin binding to ?1 integrin. Herein, we discuss differences between nascent and mature adhesions, interactions between FAK, talin and paxillin, possible mechanisms of FAK activation and how this FAK-talin complex may function to promote cell motility through increased adhesion turnover. PMID:22983197

  20. Environmentally compliant adhesive joining technology

    SciTech Connect

    Tira, J.S.

    1996-08-01

    Adhesive joining offers one method of assembling products. Advantages of adhesive joining/assembly include distribution of applied forces, lighter weight, appealing appearance, etc. Selecting environmentally safe adhesive materials and accompanying processes is paramount in today`s business climate if a company wants to be environmentally conscious and stay in business. Four areas of adhesive joining (adhesive formulation and selection, surface preparation, adhesive bonding process, waste and pollution generation/cleanup/management) all need to be carefully evaluated before adhesive joining is selected for commercial as well as military products. Designing for six sigma quality must also be addressed in today`s global economy. This requires material suppliers and product manufacturers to work even closer together.

  1. The role of fibronectin in platelet adhesion to plasma preadsorbed polystyrene.

    PubMed

    Tsai, W B; Horbett, T A

    1999-01-01

    Platelet adhesion to synthetic surfaces that come in contact with blood is mediated by the adsorption of adhesive plasma proteins, especially fibrinogen. However, the roles of other adhesive proteins, such as fibronectin, vitronectin, and von Willebrand factor in platelet adhesion are not yet clear. In this study, the role of fibronectin in platelet adhesion to surfaces was assessed using three approaches. First, platelet adhesion was measured on Immulon I preadsorbed with fibronectin-depleted plasma or fibronectin-depleted plasma replenished with increasing amount of fibronectin. Under these conditions, fibronectin adsorbed from plasma did not have any effect on platelet adhesion, while fibrinogen played a major role in mediating platelet adhesion. Since fibronectin might play a role in platelet adhesion to surfaces which adsorb little or no fibrinogen, we also used two other strategies to assess the potential role of fibronectin. One was to use platelets treated with a platelet activation inhibitor, prostaglandin E1, which prevents the activation of platelet fibrinogen receptor GP IIb/IIIa. The adhesion of prostaglandin E1-treated platelets to Immulon I preadsorbed with plasma was greatly decreased compared to that of untreated platelets, but was increased by the addition of supernormal concentrations of fibronectin to the plasma. This suggests that GP Ic/IIa, rather than GP IIb/IIIa, might be the platelet receptor which is responsible for platelet adhesion to surface-bound fibronectin. Finally, we studied the effect of fibronectin on platelet adhesion to surfaces preadsorbed with fibronectin-depleted afibrinogenemic plasma. We found that fibronectin re-addition to fibronectin-depleted afibrinogenemic plasma increased platelet adhesion. However, our most important finding was that fibronectin seems to play little or no role in mediating platelet adhesion to polystyrene surfaces preadsorbed with normal plasma. PMID:10091929

  2. Intercellular adhesion: mechanisms for growth and metastasis of epithelial cancers

    PubMed Central

    Balzer, Eric M.; Konstantopoulos, Konstantinos

    2015-01-01

    Cell–cell adhesion molecules (CAMs) comprise a broad class of linker proteins that are crucial for the development of multicellular organisms, and for the continued maintenance of organ and tissue structure. Because of its pivotal function in tissue homeostasis, the deregulation of intercellular adhesion is linked to the onset of most solid tumors. The breakdown of homeostatic cell adhesions in highly ordered epithelial sheets is directly implicated in carcinogenesis, while continued changes in the adhesion profile of the primary tumor mass facilitate growth and expansion into adjacent tissue. Intercellular adhesion molecules are also involved in each subsequent phase of metastasis, including transendothelial migration, transit through the bloodstream or lymphatics, and renewed proliferation in secondary sites. This review addresses various roles of cadherin- and selectin-mediated intercellular adhesion in tumor initiation and malignant transformation, and discusses the mechanisms for the arrest and adhesion of circulating tumor cells to the vessel endothelium. Considering the contributions of these CAMs to cancer progression in the context of a systematic biological framework may prove valuable in identifying new ways to diagnose and treat cancer. PMID:21913338

  3. Adhesion-Mediated Intracellular Redistribution of c-Fas-Associated Death Domain-Like IL1Converting Enzyme-Like Inhibitory Protein-Long Confers Resistance to CD95Induced Apoptosis in Hematopoietic Cancer Cell Lines1

    Microsoft Academic Search

    Kenneth H. Shain; Terry H. Landowski; William S. Dalton

    Evasion of immune surveillance is a key step in malignant progression. Interactions between transformed hematopoietic cells and their environment may initiate events that confer resistance to apoptosis and facilitate immune evasion. In this report, we dem- onstrate that 1 integrin-mediated adhesion to fibronectin inhibits CD95-induced caspase-8 activation and apoptosis in hemato - logic tumor cell lines. This adhesion-dependent inhibition of

  4. Increased Plasma and Endothelial Cell Expression of Chemokines and Adhesion Molecules in Chronic Kidney Disease

    Microsoft Academic Search

    A. E. M. Stinghen; S. M. Gonçalves; E. G. Martines; L. S. Nakao; M. C. Riella; C. A. Aita; R. Pecoits-Filho

    2009-01-01

    Chemokines and adhesion molecules are involved in early events of atherogenesis. In the present study, we investigated the effects of the uremic milieu on the expression of monocyte chemoattractant protein-1 (MCP-1), interleukin-8 (IL-8), soluble vascular adhesion molecule-1 (sVCAM-1) and soluble intercellular adhesion molecule-1 (sICAM-1) and their relationship to cardiovascular status. Plasma samples were obtained from patients in different stages of

  5. Structure of Slitrk2-PTP? complex reveals mechanisms for splicing-dependent trans-synaptic adhesion.

    PubMed

    Yamagata, Atsushi; Sato, Yusuke; Goto-Ito, Sakurako; Uemura, Takeshi; Maeda, Asami; Shiroshima, Tomoko; Yoshida, Tomoyuki; Fukai, Shuya

    2015-01-01

    Selective binding between pre- and postsynaptic adhesion molecules can induce synaptic differentiation. Here we report the crystal structure of a synaptogenic trans-synaptic adhesion complex between Slit and Trk-like family member 2 (Slitrk2) and receptor protein tyrosine phosphatase (RPTP) ?. The structure and site-directed mutational analysis revealed the structural basis of splicing-dependent adhesion between Slitrks and type IIa RPTPs for inducing synaptic differentiation. PMID:25989451

  6. Structure of Slitrk2–PTP? complex reveals mechanisms for splicing-dependent trans-synaptic adhesion

    PubMed Central

    Yamagata, Atsushi; Sato, Yusuke; Goto-Ito, Sakurako; Uemura, Takeshi; Maeda, Asami; Shiroshima, Tomoko; Yoshida, Tomoyuki; Fukai, Shuya

    2015-01-01

    Selective binding between pre- and postsynaptic adhesion molecules can induce synaptic differentiation. Here we report the crystal structure of a synaptogenic trans-synaptic adhesion complex between Slit and Trk-like family member 2 (Slitrk2) and receptor protein tyrosine phosphatase (RPTP) ?. The structure and site-directed mutational analysis revealed the structural basis of splicing-dependent adhesion between Slitrks and type IIa RPTPs for inducing synaptic differentiation. PMID:25989451

  7. Desmosomes and extradesmosomal adhesive signaling contacts in pemphigus.

    PubMed

    Waschke, Jens; Spindler, Volker

    2014-11-01

    Desmosomes are adhering junctions present in all cells of simple and complex epithelia. They are most abundant in cells of tissues subjected to extensive mechanical stress such as keratinocytes and cardiomyocytes. The core of desmosomes is built up of desmosomal cadherins, cadherin-type adhesion molecules that are tethered to intermediate filaments via adaptor proteins of the armadillo and the plakin family. In addition, desmosomal cadherins are present outside of desmosomes. Recent investigations indicate that these molecules are involved in adhesion-dependent and adhesion-independent signaling and thus have functions different from the adhesive properties of their counterparts within desmosomes. Impaired adhesion of desmosomal cadherins both within and outside of desmosomes is the cause of the blistering skin disease pemphigus. Autoantibodies interfere with the binding of desmosomal cadherins and alter intracellular signaling pathways, the latter of which is necessary for loss of cell adhesion. Among the plethora of signaling molecules reported, altered activities of p38MAPK, protein kinase C, and epidermal growth factor receptor (EGFR) are most relevant. This review highlights the recent data on signaling by desmosomal cadherins and the mechanisms involved in pemphigus skin blistering. PMID:24549583

  8. NR-150 adhesive development

    NASA Technical Reports Server (NTRS)

    Blatz, P. S.; Gibbs, H. H.

    1979-01-01

    A polyimide precursor adhesive solution, code-named NR-056X, was developed. It reproducibly gives low void, high strength bond lines at both room temperature and 589K (600 F) using either titanium or graphite/polyimide composite adherends having 12.7 mm (1/2 in.) overlaps. Lap shear samples prepared using this adhesive and composite adherends based on graphite/NR-150B2 were shown to have a high degree of resistance to such adverse environments as air at 589K (600 F), high humidity, methyl ethyl ketone and jet fuel. Bond line toughness was illustrated by the complete resistance to cracking in the wedge-crack propagation test. The available evidence indicates that wide area composite to composite or composite to metal bonding should be feasible.

  9. Adhesion of Lunar Dust

    Microsoft Academic Search

    Otis R. Walton

    2007-01-01

    This paper reviews the physical characteristics of lunar dust and the effects of various fundamental forces acting on dust particles on surfaces in a lunar environment. There are transport forces and adhesion forces after contact. Mechanical forces (i.e., from rover wheels, astronaut boots and rocket engine blast) and static electric effects (from UV photo-ionization and\\/or tribo-electric charging) are likely to

  10. Propulsion by directional adhesion

    Microsoft Academic Search

    John Bush; Manu Prakash

    2008-01-01

    The rough, hairy integument of water-walking arthropods is well known to be responsible for their water-repellency; we here consider its additional propulsive role. We demonstrate that the tilted flexible leg hairs of water-walking arthropods render the leg cuticle directionally anisotropic: contact lines advance most readily towards the leg tips. The dynamical role of the resulting unidirectional adhesion is explored, and

  11. Adhesive bond degradation sensor

    NASA Astrophysics Data System (ADS)

    Wilson, Alan R.; Olsson-Jacques, Christina; Muscat, Richard F.

    2002-11-01

    Early detection of adhesive bond degradation using sensing elements embedded within the 100um bond-line of aluminium epoxy adhesive joints has been demonstrated. Sensing elements of varying heights were fabricated at the ends of narrow conductors on a flexi-circuit carrier. This construction simulates the active sensing region on a patented silicon adhesive bond degradation sensor and has been used to characterize the sensing elements without the expense and time associated with fabricating the complete integrated silicon sensor. The highest elements on the flexi-circuit serve both as electrical pickup studs, providing a circuit from the flexi-circuit to the top aluminium plate, and as spacers to ensure that the shorter sensing elements do not contact the aluminium plate. The non-contacting sensing elements are thus arranged to be close to the metal/adhesive interface and are sensitive to any change in conductivity in this region due to release of ions as the interface is degraded by the environment. Accelerated aging tests were performed on flexi-circuit sensors embedded in the bond-line of double cantilever beam specimens. The specimens were immersed in 50° C water and pre-loaded to just initiate a crack. Load on the specimen was then maintained by applying a constant load point displacement with a very low velocity to ensure that the environment would degrade the bond-line in advance of the crack front. The change of load and the conductivity measured by the sensing elements were then logged with time. The onset of bond degradation was detected approximately 10-20 mm ahead of the crack tip.

  12. Fibrinogen adsorption, platelet adhesion and thrombin generation at heparinized surfaces exposed to flowing blood.

    PubMed

    Keuren, Jeffrey F W; Wielders, Simone J H; Willems, George M; Morra, Marco; Lindhout, Theo

    2002-04-01

    Thrombus formation at an artificial surface in contact with blood is a complex process that encompasses accretion of platelets from flowing blood and fibrin deposition. Platelet adhesion and fibrin formation are intimately intertwined reactions that are triggered by different sets of surface adsorbed plasma proteins. To dissect the contribution of protein adsorption and platelet adhesion to thrombin formation, a coherent study was performed with non-coated (NC) and heparin-coated (HC) surfaces. Thrombin production in whole blood, platelet adhesion and protein adsorption were studied using an amidolytic thrombin assay, a dynamic platelet adhesion assay and ellipsometry, respectively. Thrombin generation in flowing whole blood exposed to HC surfaces was greatly diminished when compared with NC surfaces. However, separate platelet adhesion and protein adsorption studies with anticoagulated whole blood revealed that platelets do not adhere because fibrinogen is not available in the protein layer that was deposited during the perfusion. These findings indicate that the in vitro thrombogenicity of a material cannot be predicted from platelet adhesion and protein adsorption data when these measurements are performed with anti-coagulated blood or platelet rich plasma. Preincubation of NC and HC surfaces with fibrinogen or 2000-fold diluted plasma resulted in similar amounts of surface-bound fibrinogen and mediated massive platelet adhesion from flowing whole blood. These results indicate that a) platelet adhesion correlates with the availability of surface-bound fibrinogen and b) NC and HC surfaces are indistinguishable with respect to protein (fibrinogen) adsorption and platelet adhesion. It is apparent that the heparinized surface used in our studies exerts its anti-thrombogenic properties by neutralizing locally formed thrombin and not by reducing fibrinogen-dependent platelet adhesion. PMID:12008960

  13. FAK promotes recruitment of talin to nascent adhesions to control cell motility

    PubMed Central

    Lawson, Christine; Lim, Ssang-Taek; Uryu, Sean; Chen, Xiao Lei; Calderwood, David A.

    2012-01-01

    Cell migration is a dynamic process that involves the continuous formation, maturation, and turnover of matrix–cell adhesion sites. New (nascent) adhesions form at the protruding cell edge in a tension-independent manner and are comprised of integrin receptors, signaling, and cytoskeletal-associated proteins. Integrins recruit focal adhesion kinase (FAK) and the cytoskeletal protein talin to nascent adhesions. Canonical models support a role for talin in mediating FAK localization and activation at adhesions. Here, alternatively, we show that FAK promotes talin recruitment to nascent adhesions occurring independently of talin binding to ?1 integrins. The direct binding site for talin on FAK was identified, and a point mutation in FAK (E1015A) prevented talin association and talin localization to nascent adhesions but did not alter integrin-mediated FAK recruitment and activation at adhesions. Moreover, FAK E1015A inhibited cell motility and proteolytic talin cleavage needed for efficient adhesion dynamics. These results support an alternative linkage for FAK–talin interactions within nascent adhesions essential for the control of cell migration. PMID:22270917

  14. FAK promotes recruitment of talin to nascent adhesions to control cell motility.

    PubMed

    Lawson, Christine; Lim, Ssang-Taek; Uryu, Sean; Chen, Xiao Lei; Calderwood, David A; Schlaepfer, David D

    2012-01-23

    Cell migration is a dynamic process that involves the continuous formation, maturation, and turnover of matrix-cell adhesion sites. New (nascent) adhesions form at the protruding cell edge in a tension-independent manner and are comprised of integrin receptors, signaling, and cytoskeletal-associated proteins. Integrins recruit focal adhesion kinase (FAK) and the cytoskeletal protein talin to nascent adhesions. Canonical models support a role for talin in mediating FAK localization and activation at adhesions. Here, alternatively, we show that FAK promotes talin recruitment to nascent adhesions occurring independently of talin binding to ?1 integrins. The direct binding site for talin on FAK was identified, and a point mutation in FAK (E1015A) prevented talin association and talin localization to nascent adhesions but did not alter integrin-mediated FAK recruitment and activation at adhesions. Moreover, FAK E1015A inhibited cell motility and proteolytic talin cleavage needed for efficient adhesion dynamics. These results support an alternative linkage for FAK-talin interactions within nascent adhesions essential for the control of cell migration. PMID:22270917

  15. [Retention or adhesion?].

    PubMed

    Sharon, E; Lipovezky-Adler, M; Haramaty, O; Smidt, A

    2013-04-01

    One of the reasons for immediate or late failure of restorations is the detachment of the restoration from the tooth. Retention for the restoration could be achieved from axial walls (macromechanical retention) or from adhesion of the restoration to the remaining tooth structure. Adhesion relies on bonding of resin cement to enamel or dentin on one side and to the restorative material on the other side. Bonding to enamel is predictable. Good bonding to dentin is more of a challenge especially with indirect restorations. In those cases the restoration is delivered usually a few days after the tooth was prepared during this time the exposed dentin might be contaminated or damaged. The question is whether you can rely on adhesion when cementing indirect restorations? In order to achieve the maximal bonding strength to dentin, the hybrid layer on the dentin must be built immediately after tooth preparation. This procedure is called Immediate Dentin Sealing. In vitro and clinical studies have shown better performance of restorations cemented following the IDS procedure. The article discusses the rational and the protocol of this procedure. A clinical case is presented as an example for the possibilities following this philosophy. PMID:24020243

  16. Regulation of Sertoli-germ cell adherens junction dynamics in the testis via the nitric oxide synthase (NOS)/cGMP/protein kinase G (PRKG)/beta-catenin (CATNB) signaling pathway: an in vitro and in vivo study.

    PubMed

    Lee, Nikki P Y; Mruk, Dolores D; Wong, Ching-Hang; Cheng, C Yan

    2005-09-01

    During spermatogenesis, extensive restructuring of cell junctions takes place in the seminiferous epithelium to facilitate germ cell movement. However, the mechanism that regulates this event remains largely unknown. Recent studies have shown that nitric oxide (NO) likely regulates tight junction (TJ) dynamics in the testis via the cGMP/protein kinase G (cGMP-dependent protein kinase, PRKG) signaling pathway. Due to the proximity of TJ and adherens junctions (AJ) in the testis, in particular at the blood-testis barrier, it is of interest to investigate if NO can affect AJ dynamics. Studies using Sertoli-germ cell cocultures in vitro have shown that the levels of NOS (nitric oxide synthase), cGMP, and PRKG were induced when anchoring junctions were being established. Using an in vivo model in which adult rats were treated with adjudin [a molecule that induces adherens junction disruption, formerly called AF-2364, 1-(2,4-dichlorobenzyl)-IH-indazole-3-carbohydrazide], the event of AJ disruption was also associated with a transient iNOS (inducible nitric oxide synthase, NOS2) induction. Immunohistochemistry has illustrated that NOS2 was intensely accumulated in Sertoli and germ cells in the epithelium during adjudin-induced germ cell loss, with a concomitant accumulation of intracellular cGMP and an induction of PRKG but not cAMP or protein kinase A (cAMP-dependent protein kinase, PRKA). To identify the NOS-mediated downstream signaling partners, coimmunoprecipitation was used to demonstrate that NOS2 and eNOS (endothelial nitric oxide synthase, NOS3) were structurally associated with the N-cadherin (CDH2)/beta-catenin (CATNB)/actin complex but not the nectin-3 (poliovirus receptor-related 3, PVRL 3)/afadin (myeloid/lymphoid or mixed lineage-leukemia tranlocation to 4 homolog, MLLT4) nor the integrin beta1 (ITB1)-mediated protein complexes, illustrating the spatial vicinity of NOS with selected AJ-protein complexes. Interestingly, CDH2 and CATNB were shown to dissociate from NOS during the adjudin-mediated AJ disruption, implicating the CDH2/CATNB protein complex is the likely downstream target of the NO signaling. Furthermore, PRKG, the downstream signaling protein of NOS, was shown to interact with CATNB in the rat testis. Perhaps the most important of all, pretreatment of testes with KT5823, a specific PRKG inhibitor, can indeed delay the adjudin-induced germ cell loss, further validating NOS/NO regulates Sertoli-germ cell AJ dynamics via the cGMP/PRKG pathway. These results illustrate that the CDH2/CATNB-mediated adhesion function in the testis is regulated, at least in part, via the NOS/cGMP/PRKG/CATNB pathway. PMID:15858215

  17. Mechanotransduction at focal adhesions: from physiology to cancer development

    PubMed Central

    Seong, Jihye; Wang, Ning; Wang, Yingxiao

    2013-01-01

    Living cells are continuously exposed to mechanical cues, and can translate these signals into biochemical information (e.g. mechanotransduction). This process is crucial in many normal cellular functions, e.g. cell adhesion, migration, proliferation, and survival, as well as the progression of diseases such as cancer. Focal adhesions are the major sites of interactions between extracellular mechanical environments and intracellular biochemical signalling molecules/cytoskeleton, and hence focal adhesion proteins have been suggested to play important roles in mechanotransduction. Here, we overview the current molecular understanding in mechanotransduction occurring at focal adhesions. We also introduce recent studies on how extracellular matrix and mechanical microenvironments contribute to the development of cancer. PMID:23601032

  18. Intact AQP0 performs cell-to-cell adhesion

    PubMed Central

    Kumari, S. Sindhu; Varadaraj, Kulandaiappan

    2010-01-01

    Aquaporins (AQPs) constitute a major conduit for movement of water across plasma membranes. AQP0 is expressed in the fiber cells and is critical for lens transparency and homeostasis as mutations and knockout have resulted in dominant lens cataract. Several functions have been attributed for AQP0. In vitro and ex vivo experiments from several laboratories have confirmed the water permeability function of AQP0. However, this function seems paradoxical when the lens switches protein expression from AQP1 in the equatorial epithelial cells to 40 times less efficient AQP0 in the differentiating fiber cells. A possible explanation is AQP0 may perform unique function/s besides being a water pore. Indirect evidences including those from structural studies indicate a cell-to-cell adhesion role for AQP0. However, there is a lack of experimental evidence directly demonstrating the cell-to-cell adhesion capability of AQP0. We studied the adhesion property of human intact AQP0 by expressing it in adhesion-deficient mouse fibroblast L-cells using a newly devised method as well as a traditional assay. Our results reveal that AQP0 indeed can perform cell-to-cell adhesion. AQP1, two alternate splice variants of AQP4 (AQP4-M1and AQP4-M23) and E-cadherin were also tested to validate the results. Cell-to-cell adhesion and cell aggregation properties of AQP0 expressing L-cells were less than those of the positive control L-cells expressing mouse E-cadherin and greater than those of AQP4-M23. AQP1 or AQP4-M1 expressing cells did not show cell-to-cell adhesion or cell aggregation. To our knowledge, this is the first report validating the possible structural role of intact AQP0 as a cell-to-cell adhesion protein, using an in vitro expression system. PMID:19857466

  19. Transglutaminase-2 in cell adhesion: all roads lead to paxillin?

    PubMed

    Png, Evelyn; Tong, Louis

    2013-01-01

    Cell-matrix adhesion is a fundamental biological process that governs survival, migration, and proliferation of living eukaryotic cells. Paxillin is an important central player in a network of adhesome proteins that form focal adhesion complexes. Phosphorylation of tyrosine and serine residues in paxillin is critical for the coordinated sequential recruitment of other adaptor and kinase proteins to adhesion complexes. Recently, the phosphorylation of serine178 in paxillin has been shown to be vital for epithelial cell adhesion and migration. In vivo and in vitro evidence have shown that transglutaminase (TG)-2 positively regulates this phosphorylation. Here, we propose three possible mechanisms that may explain these observations. First, TG-2 itself may be an adhesome member directly interacting with paxillin in a non-covalent way. Second, TG-2 may cross link a mitogen-activated protein kinase kinase kinase (MAP3K), which eventually activates c-Jun N-terminal kinase (JNK), and the latter phosphorylates paxillin. Lastly, TG-2 may have intrinsic kinase activity that phosphorylates paxillin. Future studies investigating these hypotheses on TG-2-paxillin relationships are necessary in order to address this fundamental process in cell matrix adhesion signaling. PMID:24193434

  20. Homo- and heterodimerization of APP family members promotes intercellular adhesion

    PubMed Central

    Soba, Peter; Eggert, Simone; Wagner, Katja; Zentgraf, Hanswalter; Siehl, Katjuscha; Kreger, Sylvia; Löwer, Alexander; Langer, Andreas; Merdes, Gunter; Paro, Renato; Masters, Colin L; Müller, Ulrike; Kins, Stefan; Beyreuther, Konrad

    2005-01-01

    The amyloid precursor protein (APP) plays a central role in Alzheimer's disease, but its physiological function and that of its mammalian paralogs, the amyloid precursor-like proteins 1 and 2 (APLPs), is still poorly understood. APP has been proposed to form dimers, a process that could promote cell adhesion via trans-dimerization. We investigated the dimerization and cell adhesion properties of APP/APLPs and provide evidence that all three paralogs are capable of forming homo- and heterocomplexes. Moreover, we show that trans-interaction of APP family proteins promotes cell–cell adhesion in a homo- and heterotypic fashion and that endogenous APLP2 is required for cell–cell adhesion in mouse embryonic fibroblasts. We further demonstrate interaction of all the three APP family members in mouse brain, genetic interdependence, and molecular interaction of APP and APLPs in synaptically enriched membrane compartments. Together, our results provide evidence that homo- and heterocomplexes of APP/APLPs promote trans-cellular adhesion in vivo. PMID:16193067

  1. Inhibitory effect of paclitaxel on endothelial cell adhesion and migration.

    PubMed

    Li, Hua; Zhang, Li-jun; Chen, Bai-hua; Zhou, Xuan; Su, Ke; Shi, Wen-tao; Wu, Jun-zhu; Yu, Hong; Wei, Lei

    2010-01-01

    The long-term success of percutaneous coronary interventions has been limited by restenosis. Therefore, local delivery of paclitaxel, an antiproliferative agent, using drug-eluting stents has been applied to prevent in-stent restenosis. However, paclitaxel not only inhibits smooth muscle cell proliferation, but also delays re-endothelialization of the damaged site, which may cause potentially life-threatening cardiovascular adverse events, especially late and very late stent thrombosis. We investigated the role of paclitaxel in endothelial cell line ECV304 adhesion and migration. Accordingly, changes in vasodilator-stimulated phosphoprotein protein (VASP) phosphorylation and cAMP-dependent protein kinase activity during ECV304 cell detachment and reattachment were investigated as well. The results showed that the decrease in VASP phosphorylation paralleled the inhibition of cAMP-dependent protein kinase (PKA) activity in the presence of paclitaxel (10 microg/l). Cell adhesion assay and two- and three-dimensional cell migration assays were performed to determine the effect of paclitaxel on the adhesion and migration of ECV304 cells. Paclitaxel significantly suppresses the adhesion (p < 0.05) and migration of ECV304 cells (p < 0.05). These data suggest that the inhibitory effect of paclitaxel may be produced by decreasing the phosphorylation of VASP via inhibition of PKA activity during ECV304 cell adhesion and migration. PMID:20145425

  2. Differential expression of cell adhesion molecules (CAM), neural CAM and epithelial cadherin in ependymomas and choroid plexus tumors

    Microsoft Academic Search

    Dominique Figarella-Branger; Hubert Lepidi; Christian Poncet; Danielle Gambarelli; Nicole Bianco; Geneviève Rougon; Jean-François Pellissier

    1995-01-01

    A series of frozen specimens of 18 ependymomas and 7 choroid plexus tumors were examined for their expression of cell adhesion molecules, such as neural cell adhesion molecule (NCAM), its polysialylated isoforms (PSA NCAM), and epithelial (E-) cadherin, and of intermediate filament proteins, such as glial fibrillary acidic protein (GFAP) and cytokeratin, using various monoclonal and polyclonal antibodies. Normal choroid

  3. Adhesion and aggregation ability of probiotic strain Lactobacillus acidophilus M92

    Microsoft Academic Search

    B. Kos; J. Suskovic; S. Vukovic; M. Simpraga; J. Frece; S. Matosic

    2003-01-01

    B. K OS, J. SUSKOVIC ´ ,S. V U K O V I C´ ,M. SIMPRAGA, J. F RECE A ND S. M ATOSIC ´ . 2003. Aims: To investigate aggregation and adhesiveness of Lactobacillus acidophilus M92 to porcine ileal epithelial cells in vitro, and the influence of cell surface proteins on autoaggregation and adhesiveness of this strain. Methods and

  4. The effect of brightening agents on the adhesion properties of viscose rayon cord

    Microsoft Academic Search

    E. S. Zabran; Z. G. Serebryakova; I. L. Shmurak; R. V. Uzina

    1973-01-01

    diffuse through the film of adhesive when it is of the latex-protein type. The result is that the bond between the cord and rubber is weakened to some extent. When the adhesive used was based on a latex with functional groups and a resorcin-formaldehyde resin in place of casein, neither Avirol nor other fibre brighteners affected the strength of the

  5. LI-Cadherin-mediated Cell-Cell Adhesion Does Not Require Cytoplasmic Interactions

    Microsoft Academic Search

    Bertolt Kreft; Dietmar Berndorff; Anja Böttinger; Silvia Finnemann; Doris Wedlich; Michael Hortsch; Rudolf Tauber

    1997-01-01

    The adhesive function of classical cadherins depends on the association with cytoplasmic proteins, termed catenins, which serve as a link between cad- herins and the actin cytoskeleton. LI-cadherin, a struc- turally different member of the cadherin family, medi- ates Ca 2 1 -dependent cell-cell adhesion, although its markedly short cytoplasmic domain exhibits no homol- ogy to this highly conserved region

  6. Biological performance of mussel-inspired adhesive in extrahepatic islet transplantation

    Microsoft Academic Search

    Carrie E. Brubaker; Hermann Kissler; Ling-Jia Wang; Dixon B. Kaufman; Phillip B. Messersmith

    2010-01-01

    There is significant need for effective medical adhesives that function reliably on wet tissue surfaces with minimal inflammatory insult. To address these performance characteristics, we have generated a synthetic adhesive biomaterial inspired by the protein glues of marine mussels. In-vivo performance was interrogated in a murine model of extrahepatic syngeneic islet transplantation, as an alternative to standard portal administration. The

  7. Identification and characterization of a tumor cell receptor for CSVTCG, a thrombospondin adhesive domain

    Microsoft Academic Search

    George P. Tuszynski; Vicki L. Rothman; Maria Papale; Bruce K. Hamilton; Jacob Eyal

    1993-01-01

    We have previously shown that peptides de- rived from the thrombospondin sequence, CSVTCG, promoted tumor cell adhesion. To further investigate this observation, the CSVTCG-tumor cell adhesion receptor from A549 human lung adenocarcinoma cells was isolated and characterized. A single protein peak was isolated by CSVTCG affinity chromatography which also analyzed as a single peak by anion ex- change chromatography. The

  8. Plasticity of hydrogen bond networks regulates mechanochemistry of cell adhesion complexes

    E-print Network

    Thirumalai, Devarajan

    Plasticity of hydrogen bond networks regulates mechanochemistry of cell adhesion complexes Shaon acting on cell adhesion receptor proteins regulate a range of cellular functions by formation and rupture bonds"), making the discovery that these lifetimes can also be prolonged ("catch bonds") a surprise. We

  9. Peeling of Polydimethylsiloxane Adhesives : the Case of Adhesive Claude VERDIER(1) *,

    E-print Network

    Boyer, Edmond

    Peeling of Polydimethylsiloxane Adhesives : the Case of Adhesive Failure Claude VERDIER(1 The adhesion properties of high molecular weight Polydimethylsiloxane adhesives are measured using 90°-peel effects. Recently, model polymers (Polydimethylsiloxanes, PDMS) were used10 to investigate the peeling

  10. Reinforcement of surgical adhesive strips.

    PubMed

    Mikhail, G R; Selak, L; Salo, S

    1986-09-01

    Surgical adhesive strips are often used for closure of some wounds or to minimize tension on sutures after closures. The package insert of the type most commonly used (Steri-Strip), indicates that the application of compound tincture of benzoin, U.S.P. (CTB) increases strip adhesion. The increase in adhesive power by CTB was compared with a preparation containing gum mastic (Mastisol). The study clearly demonstrated that the latter preparation provided a markedly more adhesive strength than that obtained with CTB. PMID:3528256

  11. Adhesion and migration of cells responding to microtopography.

    PubMed

    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. PMID:25089034

  12. Role of adhesion in arthropod immune recognition.

    PubMed

    Schmidt, Otto; Söderhäll, Kenneth; Theopold, Ulrich; Faye, Ingrid

    2010-01-01

    The recognition and inactivation of toxins and pathogens are mediated by a combination of cell-free and cellular mechanisms. A number of soluble and membrane-bound pattern recognition molecules interact with elicitors to become involved in both cell-free inactivation as well as cellular uptake reactions. Here we describe the possible recognition and effector function of key arthropod immune proteins, such as peroxinectin, hemolin, and hemomucin, as an outcome of changes in adhesiveness, which drive self-assembly reactions leading to cell-free coagulation and cellular uptake reactions. The fact that some of these proteins are essential for immune and developmental functions in some species, but are not found in closely related species, may point to the existence of multiprotein assemblies, which are conserved at the mechanistic level and can function with more than one combination of protein constituents. PMID:19743913

  13. Daily Consumption of Grapefruit for 6 Weeks Reduces Urine F2-Isoprostanes in Overweight Adults with High Baseline Values but Has No Effect on Plasma High-Sensitivity C-Reactive Protein or Soluble Vascular Cellular Adhesion Molecule 1123

    PubMed Central

    Dow, Caitlin A.; Wertheim, Betsy C.; Patil, Bhimanagouda S.; Thomson, Cynthia A.

    2013-01-01

    Individuals with obesity and metabolic syndrome (MetS) are at increased risk of cardiovascular disease, in part due to heightened inflammatory/oxidative processes. Results from epidemiologic and experimental studies suggest that citrus, and grapefruit in particular, may have a role in promoting vascular health, although clinical trial data are lacking. Here, we evaluated the anti-inflammatory/antioxidant effects of habitual grapefruit consumption in 69 overweight/obese men and women and in a subsample of participants with MetS (n = 29). Participants were randomly assigned to either a grapefruit group in which they consumed a low bioactive diet plus 1.5 grapefruit/d for 6 wk (n = 37, n = 14 with MetS) or to a control condition in which a low bioactive diet devoid of citrus was consumed (n = 32, n = 15 with MetS). Plasma soluble vascular adhesion molecule-1 (sVCAM-1), plasma high-sensitivity C-reactive protein (hsCRP), and urinary F2-isoprostanes were evaluated before and after the intervention phase. F2-isoprostane concentrations were not different in the grapefruit versus control arm after the intervention (12.4 ± 6.4 vs. 15.9 ± 9.0 ng/mg creatinine, P = 0.16), whereas plasma hsCRP concentrations tended to be lower in the grapefruit versus control arm postintervention (2.1 ± 1.5 vs. 2.8 ± 2.0 mg/L, P = 0.09). In adults with MetS, grapefruit consumption tended to result in lower postintervention F2-isoprostane concentrations compared with the control condition (12.0 ± 4.5 vs. 18.3 ± 10.9 ng/mg creatinine, P = 0.06). Furthermore, those with high baseline F2-isoprostane concentrations experienced significant reductions in this biomarker in response to grapefruit consumption (P = 0.021). Change in sVCAM-1 concentrations did not vary by treatment arm nor were there differences between arms postintervention. These results suggest that intake of grapefruit twice daily for 6 wk does not significantly reduce inflammation and oxidative stress, although there is a suggestion of favorable modulation of oxidative stress in overweight and obese adults with MetS or those with high baseline urine F2-isoprostane concentrations. PMID:23902962

  14. 3D Integration Using Adhesive, Metal, and Metal/Adhesive as Wafer Bonding Interfaces.

    E-print Network

    Salama, Khaled

    3D Integration Using Adhesive, Metal, and Metal/Adhesive as Wafer Bonding Interfaces. Journal: 2008 Integration Using Adhesive, Metal, and Metal/Adhesive as Wafer Bonding Interfaces Jian-Qiang Lu1 , J. Jay Mc approaches to 3D integration using adhesive, metal, and metal/adhesive as the bonding interfaces

  15. Adhesive interactions of biologically inspired soft condensed matter

    NASA Astrophysics Data System (ADS)

    Anderson, Travers Heath

    Improving our fundamental understanding of the surface interactions between complex materials is needed to improve existing materials and products as well as develop new ones. The object of this research was to apply the measurements of fundamental surface interactions to real world problems facing chemical engineers and materials scientists. I focus on three systems of biologically inspired soft condensed matter, with an emphasis on the adhesive interactions between them. The formation of phospholipid bilayers of the neutral lipid, dimyristoyl-phosphatidylcholine (DMPC) on silica surfaces from vesicles in aqueous solutions was investigated. The process involves five stages: vesicle adhesion to the substrate surfaces, steric interactions with neighboring vesicles, rupture, spreading via hydrophobic fusion of bilayer edges, and ejection of excess lipid, trapped water and ions into the solution. The forces between DMPC bilayers and silica were measured in the Surface Forces Apparatus (SFA) in phosphate buffered saline. The adhesion energy was found to be much stronger than the expected adhesion predicted by van der Waals interactions, likely due to an attractive electrostatic interaction. The effects of non-adsorbing cationic polyelectrolytes on the interactions between supported cationic surfactant bilayers were studied using the SFA. Addition of polyelectrolyte has a number of effects on the interactions including the induction of a depletion-attraction and screening of the double-layer repulsion. Calculations are made that allow for the conversion of the adhesion energy measured in the SFA to the overall interaction energy between vesicles in solution, which determines the stability behavior of vesicle dispersions. Mussels use a variety of dihydroxyphenyl-alanine (DOPA) rich proteins specifically tailored to adhering to wet surfaces. The SFA was used to study the role of DOPA on the adhesive properties of these proteins to TiO 2 and mica using both real mussel foot proteins (mfp) and a synthetic polypeptide analogue of mfp-3. Adhesion increased with DOPA concentration, although oxidation of DOPA reduces the adhesive capabilities of the proteins. Comparison of the two shows that DOPA is responsible for at least 80% of the adhesion energy of mfp-3 and can be attributed to DOPA groups favorably oriented within or at the interface of these films.

  16. Effect of adhesive thickness on adhesively bonded T-joint

    NASA Astrophysics Data System (ADS)

    Abdullah, A. R.; Afendi, Mohd; Majid, M. S. Abdul

    2013-12-01

    The aim of this work is to analyze the effect of adhesive thickness on tensile strength of adhesively bonded stainless steel T-joint. Specimens were made from SUS 304 Stainless Steel plate and SUS 304 Stainless Steel perforated plate. Four T-joint specimens with different adhesive thicknesses (0.5, 1.0, 1.5 and 2.0 mm) were made. Experiment result shows T-joint specimen with adhesive thickness of 1.0 mm yield highest maximum load. Identical T-joint specimen jointed by spot welding was also tested. Tensile test shows welded T-Joint had eight times higher tensile load than adhesively bonded T-joint. However, in low pressure application such as urea granulator chamber, high tensile strength is not mandatory. This work is useful for designer in fertilizer industry and others who are searching for alternative to spot welding.

  17. Protein

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Proteins are the major structural and functional components of all cells in the body. They are macromolecules that comprise 1 or more chains of amino acids that vary in their sequence and length and are folded into specific 3-dimensional structures. The sizes and conformations of proteins, therefor...

  18. Proteins.

    ERIC Educational Resources Information Center

    Doolittle, Russell F.

    1985-01-01

    Examines proteins which give rise to structure and, by virtue of selective binding to other molecules, make genes. Binding sites, amino acids, protein evolution, and molecular paleontology are discussed. Work with encoding segments of deoxyribonucleic acid (exons) and noncoding stretches (introns) provides new information for hypotheses. (DH)

  19. Proteins

    NSDL National Science Digital Library

    Mowery, Jeanette

    Laboratory manual and supplemental resources that were developed for a college laboratory course in protein purification. The enzyme, Beta-galactosidase, is purified in two steps, with analysis and verification of results. Course materials are divided into four units: Why Proteins, Assays, The Purification Process, and Analysis and Verification. Powerpoint lectures and study guides are provided.

  20. Effect of fibril shape on adhesive properties

    NASA Astrophysics Data System (ADS)

    Soto, Daniel; Hill, Ginel; Parness, Aaron; Esparza, Noé; Cutkosky, Mark; Kenny, Tom

    2010-08-01

    Research into the gecko's adhesive system revealed a unique architecture for adhesives using tiny hairs. By using a stiff material (?-keratin) to create a highly structured adhesive, the gecko's system demonstrates properties not seen in traditional pressure-sensitive adhesives which use a soft, unstructured planar layer. In contrast to pressure sensitive adhesives, the gecko adhesive displays frictional adhesion, in which increased shear force allows it to withstand higher normal loads. Synthetic fibrillar adhesives have been fabricated but not all demonstrate this frictional adhesion property. Here we report the dual-axis force testing of single silicone rubber pillars from synthetic adhesive arrays. We find that the shape of the adhesive pillar dictates whether frictional adhesion or pressure-sensitive behavior is observed. This work suggests that both types of behavior can be achieved with structures much larger than gecko terminal structures. It also indicates that subtle differences in the shape of these pillars can significantly influence their properties.

  1. Junction Adhesion Molecule Is a Receptor for Reovirus

    Microsoft Academic Search

    Erik S. Barton; J. Craig Forrest; Jodi L. Connolly; James D. Chappell; Yuan Liu; Frederick J. Schnell; Asma Nusrat; Charles A. Parkos; Terence S. Dermody

    2001-01-01

    Virus attachment to cells plays an essential role in viral tropism and disease. Reovirus serotypes 1 and 3 differ in the capacity to target distinct cell types in the murine nervous system and in the efficiency to induce apoptosis. The binding of viral attachment protein ?1 to unidentified receptors controls these phenotypes. We used expression cloning to identify junction adhesion

  2. Bone morphogenetic protein antagonist gremlin-1 regulates colon cancer progression.

    PubMed

    Karagiannis, George S; Musrap, Natasha; Saraon, Punit; Treacy, Ann; Schaeffer, David F; Kirsch, Richard; Riddell, Robert H; Diamandis, Eleftherios P

    2015-02-01

    Bone morphogenetic proteins (BMP) are phylogenetically conserved signaling molecules of the transforming growth factor-beta (TGF-beta) superfamily of proteins, involved in developmental and (patho)physiological processes, including cancer. BMP signaling has been regarded as tumor-suppressive in colorectal cancer (CRC) by reducing cancer cell proliferation and invasion, and by impairing epithelial-to-mesenchymal transition (EMT). Here, we mined existing proteomic repositories to explore the expression of BMPs in CRC. We found that the BMP antagonist gremlin-1 (GREM1) is secreted from heterotypic tumor-host cell interactions. We then sought to investigate whether GREM1 is contextually and mechanistically associated with EMT in CRC. Using immunohistochemistry, we showed that GREM1-expressing stromal cells harbor prominent features of myofibroblasts (i.e., cancer-associated fibroblasts), such as expression of ?-smooth muscle actin and laminin-beta-1, and were in contextual proximity to invasion fronts with loss of the tight junction protein occludin and parallel nuclear accumulation of ?-catenin, two prominent EMT hallmarks. Furthermore, in vitro assays demonstrated that GREM1-dependent suppression of BMP signaling results in EMT induction, characterized by cadherin switching (loss of E-cadherin-upregulation of N-cadherin) and overexpression of Snail. Collectively, our data support that GREM1 promotes the loss of cancer cell differentiation at the cancer invasion front, a mechanism that may facilitate tumor progression. PMID:25153376

  3. Arrays of Self-Assembled Monolayers for Studying Inhibition of Bacterial Adhesion

    E-print Network

    Prentiss, Mara

    ) presented on a 96-well microtiter plate. Adhesion to the surface of host cells is an essential step proteins that recognize ligands on the cell surface.7 The complexity of the diverse carbohydrates presented

  4. Bacterial adhesion to orthopaedic implant materials and a novel oxygen plasma modified PEEK surface.

    PubMed

    Rochford, E T J; Poulsson, A H C; Salavarrieta Varela, J; Lezuo, P; Richards, R G; Moriarty, T F

    2014-01-01

    Despite extensive use of polyetheretherketone (PEEK) in biomedical applications, information about bacterial adhesion to this biomaterial is limited. This study investigated Staphylococcus aureus and Staphylococcus epidermidis adhesion to injection moulded and machined PEEK OPTIMA(®) using a custom-built adhesion chamber with medical grade titanium and Thermanox for comparison. Additionally, bacterial adhesion to a novel oxygen plasma modified PEEK was also investigated in both a pre-operative model in physiological saline, and additionally in a post-operative model in human blood plasma. In the pre-operative model, the rougher machined PEEK had a significantly greater number of adherent bacteria compared to injection moulded PEEK. Bacterial adhesion to titanium and Thermanox was similar. Oxygen plasma surface modification of PEEK did not lead to a significant change in bacterial adhesion in the pre-operative contamination model, despite observed changes in surface characteristics. In the post-operative contamination model, S. aureus adhesion was increased from 5×10(5) CFU cm(-2) to approximately 1.3×10(7) CFU cm(-2) on the modified surfaces due to differential protein adhesion during the conditioning period. However, S. epidermidis adhesion to modified PEEK was less than to unmodified PEEK in the post-operative model. These results illustrate the importance of testing bacterial adhesion of several strains in both a pre-operative and post-operative, clinically relevant bacterial contamination model. PMID:24103502

  5. Bone morphogenetic protein 2 mediates epithelial-mesenchymal transition via AKT and ERK signaling pathways in gastric cancer.

    PubMed

    Liao, Anyan; Wang, Weijie; Sun, Dawei; Jiang, Yuliang; Tian, Suqing; Li, Jinna; Yang, Xiangshan; Shi, Ranran

    2015-04-01

    Although deregulation of bone morphogenetic protein 2 (BMP2) signaling has been linked to various types of cancers, the relationships between abnormal activation of these signaling pathways and tumorigenesis are not clear in gastric cancer. We hypothesized that BMP2 might be involved in epithelial-mesenchymal transition (EMT) process of gastric cancer. Here, BMPR-II activation and inhibition in gastric cancer cell line AGS were induced with exogenous BMP2 and with BMPR-II small interfering RNA (siRNA), respectively. BMPR-II downstream signal molecules AKT, ERK phosphorylation, and EMT biomarkers (vimentin, snail, N-cadherin, and E-cadherin) were tested using the Western blot. In the present study, our results showed that BMP2 can induce AKT and ERK phosphorylation in a dose-dependent method, and endogenous BMPR-II can be inhibited completely by BMPR-II siRNA in AGS. Notably BMP2 alone treatment can induce the up-regulation of vimentin, snail, and N-cadherin in AGS cells, besides, the down-regulation of E-cadherin also occurred. On the contrary, BMPR-II siRNA significantly prohibited BMP2-induced AKT and ERK phosphorylation, at the same time, EMT biomarkers changes were not observed. On the other hand, BMPR-II knockdown could significantly affect AGS wound closure and the migration ability (p?

  6. Fire-Retardant Epoxy Adhesives

    NASA Technical Reports Server (NTRS)

    Bilow, N.; Giants, T. W.

    1982-01-01

    Phosphorus-containing epoxy is fire-retardant and translucent. Intended as adhesive for laminated plastic sheets, new material bonds well to titanium dioxide-filled plastic film, which ordinarily shows little surface interaction with adhesives. Fire retardancy has been demonstrated, and smoke density is low enough to avoid smoke obscuration.

  7. Adhesive secretions in the platyhelminthes

    Microsoft Academic Search

    Ian D. Whittington; Bronwen W. Cribb

    2001-01-01

    This review is the first to draw together knowledge about bioadhesives secreted by a group of parasites. Mechanisms of mechanical attachment are well known among parasites, but some can also attach to host surfaces by chemical means using a thin layer of adhesive material secreted at the parasite-host interface. Attachment by adhesives to living surfaces has not been studied in

  8. Bacterial Adhesion at Synthetic Surfaces

    Microsoft Academic Search

    D. CUNLIFFE; C. A. SMART; C. ALEXANDER; E. N. VULFSON

    1999-01-01

    A systematic investigation into the effect of surface chemistry on bacterial adhesion was carried out. In particular, a number of physicochemical factors important in defining the surface at the molecular level were assessed for their effect on the adhesion of Listeria monocytogenes, Salmonella typhimurium, Staphylococcus aureus, and Escherichia coli. The primary experiments involved the grafting of groups varying in hydrophilicity,

  9. Salivary amylase promotes adhesion of oral streptococci to hydroxyapatite.

    PubMed

    Scannapieco, F A; Torres, G I; Levine, M J

    1995-07-01

    Recent studies have demonstrated that several species of oral streptococci, such as Streptococcus gordonii, bind soluble salivary alpha-amylase. The goal of the present study was to determine if amylase immobilized onto a surface such as hydroxyapatite can serve as an adhesion receptor for S. gordonii. Initially, human parotid saliva was fractionated on Bio-Gel P60, and fractions were screened for their ability to promote adhesion of S. gordonii to hydroxyapatite. Fractions containing alpha-amylase and proline-rich proteins promoted the adhesion of [3H]-labeled S. gordonii to hydroxyapatite. Similar findings were obtained with purified amylase and acidic proline-rich protein 1 (PRP1). Incubation of S. gordonii G9B in the presence of starch and maltotriose increased the binding of this strain to amylase-coated hydroxyapatite, while the adhesion of S. sanguis 10556 to amylase-coated hydroxyapatite was not affected by these saccharides. These results suggest that amylase may serve as a hydroxyapatite pellicle receptor for amylase-binding streptococci. Furthermore, starch and starch metabolites may enhance the adhesion of amylase-binding streptococci to amylase in dental pellicles to augment the formation of dental plaque. PMID:7560386

  10. The FRIABLE1 Gene Product Affects Cell Adhesion in Arabidopsis

    PubMed Central

    Neumetzler, Lutz; Humphrey, Tania; Lumba, Shelley; Snyder, Stephen; Yeats, Trevor H.; Usadel, Björn; Vasilevski, Aleksandar; Patel, Jignasha; Rose, Jocelyn K. C.; Persson, Staffan; Bonetta, Dario

    2012-01-01

    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. PMID:22916179

  11. Cell Adhesion-dependent Serine 85 Phosphorylation of Paxillin Modulates Focal Adhesion Formation and Haptotactic Migration via Association with the C-terminal Tail Domain of Talin*

    PubMed Central

    Kwak, Tae Kyoung; Lee, Mi-Sook; Ryu, Jihye; Choi, Yoon-Ju; Kang, Minkyung; Jeong, Doyoung; Lee, Jung Weon

    2012-01-01

    Integrin-mediated adhesion to extracellular matrix proteins is dynamically regulated during morphological changes and cell migration. Upon cell adhesion, protein-protein interactions among molecules at focal adhesions (FAs) play major roles in the regulation of cell morphogenesis and migration. Although tyrosine phosphorylation of paxillin is critically involved in adhesion-mediated signaling, the significance of paxillin phosphorylation at Ser-85 and the mechanism by which it regulates cell migration remain unclear. In this study, we examined how Ser-85 phosphorylation of paxillin affects FA formation and cell migration. We found that paxillin phosphorylation at Ser-85 occurred during HeLa cell adhesion to collagen I and was concomitant with tyrosine phosphorylation of both focal adhesion kinase and talin. However, the non-phosphorylatable S85A mutant of paxillin impaired cell spreading, FA turnover, and migration toward collagen I but not toward serum. Furthermore, whereas the (presumably indirect) interaction between paxillin and the C-terminal tail of talin led to dynamic FAs at the cell boundary, S85A paxillin did not bind talin and caused stabilized FAs in the central region of cells. Together, these observations suggest that cell adhesion-dependent Ser-85 phosphorylation of paxillin is important for its interaction with talin and regulation of dynamic FAs and cell migration. PMID:22761432

  12. Cell adhesion-dependent serine 85 phosphorylation of paxillin modulates focal adhesion formation and haptotactic migration via association with the C-terminal tail domain of talin.

    PubMed

    Kwak, Tae Kyoung; Lee, Mi-Sook; Ryu, Jihye; Choi, Yoon-Ju; Kang, Minkyung; Jeong, Doyoung; Lee, Jung Weon

    2012-08-10

    Integrin-mediated adhesion to extracellular matrix proteins is dynamically regulated during morphological changes and cell migration. Upon cell adhesion, protein-protein interactions among molecules at focal adhesions (FAs) play major roles in the regulation of cell morphogenesis and migration. Although tyrosine phosphorylation of paxillin is critically involved in adhesion-mediated signaling, the significance of paxillin phosphorylation at Ser-85 and the mechanism by which it regulates cell migration remain unclear. In this study, we examined how Ser-85 phosphorylation of paxillin affects FA formation and cell migration. We found that paxillin phosphorylation at Ser-85 occurred during HeLa cell adhesion to collagen I and was concomitant with tyrosine phosphorylation of both focal adhesion kinase and talin. However, the non-phosphorylatable S85A mutant of paxillin impaired cell spreading, FA turnover, and migration toward collagen I but not toward serum. Furthermore, whereas the (presumably indirect) interaction between paxillin and the C-terminal tail of talin led to dynamic FAs at the cell boundary, S85A paxillin did not bind talin and caused stabilized FAs in the central region of cells. Together, these observations suggest that cell adhesion-dependent Ser-85 phosphorylation of paxillin is important for its interaction with talin and regulation of dynamic FAs and cell migration. PMID:22761432

  13. A Lily Stylar Pectin Is Necessary for Pollen Tube Adhesion to an in Vitro Stylar Matrix

    PubMed Central

    Mollet, Jean-Claude; Park, Sang-Youl; Nothnagel, Eugene A.; Lord, Elizabeth M.

    2000-01-01

    Pollen tube cells adhere to the wall surface of the stylar transmitting tract epidermis in lily. This adhesion has been proposed as essential for the proper delivery of the sperm cells to the ovule. An in vitro adhesion bioassay has been used to isolate two stylar molecules required for lily pollen tube adhesion. The first molecule was determined to be a small, cysteine-rich protein with some sequence similarity to lipid transfer proteins and now called stigma/stylar cysteine-rich adhesin (SCA). The second, larger, molecule has now been purified from style fragments and characterized. Chemical composition, specific enzyme degradations, and immunolabeling data support the idea that this molecule required for pollen tube adhesion is a pectic polysaccharide. In vitro binding assays revealed that this lily stylar adhesive pectin and SCA are able to bind to each other in a pH-dependent manner. PMID:11006344

  14. p38 MAP kinase modulates Smad-dependent changes in human prostate cell adhesion

    Microsoft Academic Search

    Steven A Hayes; Xiaoke Huang; Suman Kambhampati; Leonidas C Platanias; Raymond C Bergan

    2003-01-01

    Transforming growth factor beta (TGF?) regulates cell adhesion, proliferation, and differentiation in a variety of cells. Smad proteins are receptor-activated transcription factors that translocate to the nucleus in response to TGF?. We demonstrate here that TGF? increases cell adhesion in metastatic PC3-M prostate cancer cells. TGF? treatment of PC3-M cells leads to nuclear translocation of R-Smad proteins. We show that

  15. Serine and Threonine Phosphorylation of the Paxillin LIM Domains Regulates Paxillin Focal Adhesion Localization and Cell Adhesion to Fibronectin

    PubMed Central

    Brown, Michael C.; Perrotta, Joseph A.; Turner, Christopher E.

    1998-01-01

    We have previously shown that the LIM domains of paxillin operate as the focal adhesion (FA)-targeting motif of this protein. In the current study, we have identified the capacity of paxillin LIM2 and LIM3 to serve as binding sites for, and substrates of serine/threonine kinases. The activities of the LIM2- and LIM3-associated kinases were stimulated after adhesion of CHO.K1 cells to fibronectin; consequently, a role for LIM domain phosphorylation in regulating the subcellular localization of paxillin after adhesion to fibronectin was investigated. An avian paxillin-CHO.K1 model system was used to explore the role of paxillin phosphorylation in paxillin localization to FAs. We found that mutations of paxillin that mimicked LIM domain phosphorylation accelerated fibronectin-induced localization of paxillin to focal contacts. Further, blocking phosphorylation of the LIM domains reduced cell adhesion to fibronectin, whereas constitutive LIM domain phosphorylation significantly increased the capacity of cells to adhere to fibronectin. The potentiation of FA targeting and cell adhesion to fibronectin was specific to LIM domain phosphorylation as mutation of the amino-terminal tyrosine and serine residues of paxillin that are phosphorylated in response to fibronectin adhesion had no effect on the rate of FA localization or cell adhesion. This represents the first demonstration of the regulation of protein localization through LIM domain phosphorylation and suggests a novel mechanism of regulating LIM domain function. Additionally, these results provide the first evidence that paxillin contributes to “inside-out” integrin-mediated signal transduction. PMID:9658172

  16. Osteoblast adhesion to orthopaedic implant alloys: Effects of cell adhesion molecules and diamond-like carbon coating

    SciTech Connect

    Kornu, R.; Kelly, M.A.; Smith, R.L. [Stanford Univ., CA (United States); Maloney, W.J. [Washington Univ., St. Louis, MO (United States)

    1996-11-01

    In total joint arthroplasty, long-term outcomes depend in part on the biocompatibility of implant alloys. This study analyzed effects of surface finish and diamond-like carbon coating on osteoblast cell adhesion to polished titanium-aluminum-vanadium and polished or grit-blasted cobalt-chromium-molybdenum alloys. Osteoblast binding was tested in the presence and absence of the cell adhesion proteins fibronectin, laminin, fibrinogen, and vitronectin and was quantified by measurement of DNA content. Although adherence occurred in serum-free medium, maximal osteoblast binding required serum and was similar for titanium and cobalt alloys at 2 and 12 hours. With the grit-blasted cobalt alloy, cell binding was reduced 48% (p < 0.05) by 24 hours. Coating the alloys with diamond-like carbon did not alter osteoblast adhesion, whereas fibronectin pretreatment increased cell binding 2.6-fold (p < 0.05). In contrast, fibrinogen, vitronectin, and laminin did not enhance cell adhesion. These results support the hypothesis that cell adhesion proteins can modify cell binding to orthopaedic alloys. Although osteoblast binding was not affected by the presence of diamond-like carbon, this coating substance may influence other longer term processes, such as bone formation, and deserves further study. 40 refs., 4 figs.

  17. Dipeptidyl peptidase 9 subcellular localization and a role in cell adhesion involving focal adhesion kinase and paxillin.

    PubMed

    Zhang, Hui; Chen, Yiqian; Wadham, Carol; McCaughan, Geoffrey W; Keane, Fiona M; Gorrell, Mark D

    2015-02-01

    Dipeptidyl peptidase 9 (DPP9) is a ubiquitously expressed member of the DPP4 gene and protease family. Deciphering the biological functions of DPP9 and its roles in pathogenesis has implicated DPP9 in tumor biology, the immune response, apoptosis, intracellular epidermal growth factor-dependent signaling and cell adhesion and migration. We investigated the intracellular distribution of DPP9 chimeric fluorescent proteins and consequent functions of DPP9. We showed that while some DPP9 is associated with mitochondria, the strongest co-localization was with microtubules. Under steady state conditions, DPP9 was not seen at the plasma membrane, but upon stimulation with either phorbol 12-myristate 13-acetate or epidermal growth factor, some DPP9 re-distributed towards the ruffling membrane. DPP9 was seen at the leading edge of the migrating cell and co-localized with the focal adhesion proteins, integrin-?1 and talin. DPP9 gene silencing and treatment with a DPP8/DPP9 specific inhibitor both reduced cell adhesion and migration. Expression of integrin-?1 and talin was decreased in DPP9-deficient and DPP9-enzyme-inactive cells. There was a concomitant decrease in the phosphorylation of focal adhesion kinase and paxillin, indicating that DPP9 knockdown or enzyme inhibition suppressed the associated adhesion signaling pathway, causing impaired cell movement. These novel findings provide mechanistic insights into the regulatory role of DPP9 in cell movement, and may thus implicate DPP9 in tissue and tumor growth and metastasis. PMID:25486458

  18. Protein

    MedlinePLUS

    ... for the heart. Alternatively, a cup of cooked lentils provides about 18 grams of protein and 15 ... eating approximately one daily serving of beans, chickpeas, lentils or peas can increase fullness, which may lead ...

  19. Poldip2 controls vascular smooth muscle cell migration by regulating focal adhesion turnover and force polarization.

    PubMed

    Datla, Srinivasa Raju; McGrail, Daniel J; Vukelic, Sasa; Huff, Lauren P; Lyle, Alicia N; Pounkova, Lily; Lee, Minyoung; Seidel-Rogol, Bonnie; Khalil, Mazen K; Hilenski, Lula L; Terada, Lance S; Dawson, Michelle R; Lassègue, Bernard; Griendling, Kathy K

    2014-10-01

    Polymerase-?-interacting protein 2 (Poldip2) interacts with NADPH oxidase 4 (Nox4) and regulates migration; however, the precise underlying mechanisms are unclear. Here, we investigated the role of Poldip2 in focal adhesion turnover, as well as traction force generation and polarization. Poldip2 overexpression (AdPoldip2) in vascular smooth muscle cells (VSMCs) impairs PDGF-induced migration and induces a characteristic phenotype of long cytoplasmic extensions. AdPoldip2 also prevents the decrease in spreading and increased aspect ratio observed in response to PDGF and slightly impairs cell contraction. Moreover, AdPoldip2 blocks focal adhesion dissolution and sustains H2O2 levels in focal adhesions, whereas Poldip2 knockdown (siPoldip2) significantly decreases the number of focal adhesions. RhoA activity is unchanged when focal adhesion dissolution is stimulated in control cells but increases in AdPoldip2-treated cells. Inhibition of RhoA blocks Poldip2-mediated attenuation of focal adhesion dissolution, and overexpression of RhoA or focal adhesion kinase (FAK) reverses the loss of focal adhesions induced by siPoldip2, indicating that RhoA and FAK mediate the effect of Poldip2 on focal adhesions. Nox4 silencing prevents focal adhesion stabilization by AdPoldip2 and induces a phenotype similar to siPoldip2, suggesting a role for Nox4 in Poldip2-induced focal adhesion stability. As a consequence of impaired focal adhesion turnover, PDGF-treated AdPoldip2 cells are unable to reduce and polarize traction forces, a necessary first step in migration. These results implicate Poldip2 in VSMC migration via regulation of focal adhesion turnover and traction force generation in a Nox4/RhoA/FAK-dependent manner. PMID:25063792

  20. Wet Adhesion and Adhesive Locomotion of Snails on Anti-Adhesive Non-Wetting Surfaces

    PubMed Central

    Shirtcliffe, Neil J.; McHale, Glen; Newton, Michael I.

    2012-01-01

    Creating surfaces capable of resisting liquid-mediated adhesion is extremely difficult due to the strong capillary forces that exist between surfaces. Land snails use this to adhere to and traverse across almost any type of solid surface of any orientation (horizontal, vertical or inverted), texture (smooth, rough or granular) or wetting property (hydrophilic or hydrophobic) via a layer of mucus. However, the wetting properties that enable snails to generate strong temporary attachment and the effectiveness of this adhesive locomotion on modern super-slippy superhydrophobic surfaces are unclear. Here we report that snail adhesion overcomes a wide range of these microscale and nanoscale topographically structured non-stick surfaces. For the one surface which we found to be snail resistant, we show that the effect is correlated with the wetting response of the surface to a weak surfactant. Our results elucidate some critical wetting factors for the design of anti-adhesive and bio-adhesion resistant surfaces. PMID:22693563

  1. Wet adhesion and adhesive locomotion of snails on anti-adhesive non-wetting surfaces.

    PubMed

    Shirtcliffe, Neil J; McHale, Glen; Newton, Michael I

    2012-01-01

    Creating surfaces capable of resisting liquid-mediated adhesion is extremely difficult due to the strong capillary forces that exist between surfaces. Land snails use this to adhere to and traverse across almost any type of solid surface of any orientation (horizontal, vertical or inverted), texture (smooth, rough or granular) or wetting property (hydrophilic or hydrophobic) via a layer of mucus. However, the wetting properties that enable snails to generate strong temporary attachment and the effectiveness of this adhesive locomotion on modern super-slippy superhydrophobic surfaces are unclear. Here we report that snail adhesion overcomes a wide range of these microscale and nanoscale topographically structured non-stick surfaces. For the one surface which we found to be snail resistant, we show that the effect is correlated with the wetting response of the surface to a weak surfactant. Our results elucidate some critical wetting factors for the design of anti-adhesive and bio-adhesion resistant surfaces. PMID:22693563

  2. Cadherin-catenin adhesion complexes at the synapse.

    PubMed

    Brigidi, G Stefano; Bamji, Shernaz X

    2011-04-01

    Classic cadherins function as key organizers during the formation and remodeling of synapses in the vertebrate central nervous system. Cadherins are Ca2+-dependent homophilic adhesion molecules whose adhesive strength can be regulated by conformational changes, through cadherin's association with intracellular binding proteins, and by the regulation of cadherin turnover and internalization. In this mini-review, we will highlight recent studies on the role of cadherins and their associated partners in regulating synaptic architecture. Moreover, we will discuss molecular mechanisms underlying cadherin turnover and the subsequent impact on synaptic connections. PMID:21255999

  3. Adhesively-bonded joints and repairs in metallic alloys, polymers and composite materials: Adhesives, adhesion theories and surface pretreatment

    Microsoft Academic Search

    A. Baldan

    2004-01-01

    In the present paper, the following topics are reviewed in detail: (a) the available adhesives, as well as their recent advances, (b) thermodynamic factors affecting the surface pretreatments including adhesion theories, wettability, surface energy, (c) bonding mechanisms in the adhesive joints, (d) surface pretreatment methods for the adhesively bonded joints, and as well as their recent advances, and (e) combined

  4. Surface Modifications in Adhesion and Wetting

    NASA Astrophysics Data System (ADS)

    Longley, Jonathan

    Advances in surface modification are changing the world. Changing surface properties of bulk materials with nanometer scale coatings enables inventions ranging from the familiar non-stick frying pan to advanced composite aircraft. Nanometer or monolayer coatings used to modify a surface affect the macro-scale properties of a system; for example, composite adhesive joints between the fuselage and internal frame of Boeing's 787 Dreamliner play a vital role in the structural stability of the aircraft. This dissertation focuses on a collection of surface modification techniques that are used in the areas of adhesion and wetting. Adhesive joints are rapidly replacing the familiar bolt and rivet assemblies used by the aerospace and automotive industries. This transition is fueled by the incorporation of composite materials into aircraft and high performance road vehicles. Adhesive joints have several advantages over the traditional rivet, including, significant weight reduction and efficient stress transfer between bonded materials. As fuel costs continue to rise, the weight reduction is accelerating this transition. Traditional surface pretreatments designed to improve the adhesion of polymeric materials to metallic surfaces are extremely toxic. Replacement adhesive technologies must be compatible with the environment without sacrificing adhesive performance. Silane-coupling agents have emerged as ideal surface modifications for improving composite joint strength. As these coatings are generally applied as very thin layers (<50 nm), it is challenging to characterize their material properties for correlation to adhesive performance. We circumvent this problem by estimating the elastic modulus of the silane-based coatings using the buckling instability formed between two materials of a large elastic mismatch. The elastic modulus is found to effectively predict the joint strength of an epoxy/aluminum joint that has been reinforced with silane coupling agents. This buckling technique is extended to investigate the effects of chemical composition on the elastic modulus. Finally, the effect of macro-scale roughness on silane-reinforced joints is investigated within the framework of the unresolved problem of how to best characterize rough surfaces. Initially, the