BIGH3 modulates adhesion and migration of hematopoietic stem and progenitor cells

PubMed Central

Klamer, Sofieke E; Kuijk, Carlijn GM; Hordijk, Peter L; van der Schoot, C Ellen; von Lindern, Marieke; van Hennik, Paula B; Voermans, Carlijn

2013-01-01

Cell adhesion and migration are important determinants of homing and development of hematopoietic stem and progenitor cells (HSPCs) in bone marrow (BM) niches. The extracellular matrix protein transforming growth factor-β (TGF-β) inducible gene H3 (BIGH3) is involved in adhesion and migration, although the effect of BIGH3 is highly cell type-dependent. BIGH3 is abundantly expressed by mesenchymal stromal cells, while its expression in HSPCs is relatively low unless induced by certain BM stressors. Here, we set out to determine how BIGH3 modulates HSPC adhesion and migration. We show that primary HSPCs adhere to BIGH3-coated substrates, which is, in part, integrin-dependent. Overexpression of BIGH3 in HSPCs and HL60 cells reduced the adhesion to the substrate fibronectin in adhesion assays, which was even more profound in electrical cell-substrate impedance sensing (ECIS) assays. Accordingly, the CXCL12 induced migration over fibronectin-coated surface was reduced in BIGH3-expressing HSPCs. The integrin expression profile of HSPCs was not altered upon BIGH3 expression. Although expression of BIGH3 did not alter actin polymerization in response to CXCL12, it inhibited the PMA-induced activation of the small GTPase RAC1 as well as the phosphorylation and activation of extracellular-regulated kinases (ERKs). Reduced activation of ERK and RAC1 may be responsible for the inhibition of cell adhesion and migration by BIGH3 in HSPCs. Induced BIGH3 expression upon BM stress may contribute to the regulation of BM homeostasis. PMID:24152593

Systems toxicology-based assessment of the candidate modified risk tobacco product THS2.2 for the adhesion of monocytic cells to human coronary arterial endothelial cells.

PubMed

Poussin, Carine; Laurent, Alexandra; Peitsch, Manuel C; Hoeng, Julia; De Leon, Hector

2016-01-02

Alterations of endothelial adhesive properties by cigarette smoke (CS) can progressively favor the development of atherosclerosis which may cause cardiovascular disorders. Modified risk tobacco products (MRTPs) are tobacco products developed to reduce smoking-related risks. A systems biology/toxicology approach combined with a functional in vitro adhesion assay was used to assess the impact of a candidate heat-not-burn technology-based MRTP, Tobacco Heating System (THS) 2.2, on the adhesion of monocytic cells to human coronary arterial endothelial cells (HCAECs) compared with a reference cigarette (3R4F). HCAECs were treated for 4h with conditioned media of human monocytic Mono Mac 6 (MM6) cells preincubated with low or high concentrations of aqueous extracts from THS2.2 aerosol or 3R4F smoke for 2h (indirect treatment), unconditioned media (direct treatment), or fresh aqueous aerosol/smoke extracts (fresh direct treatment). Functional and molecular investigations revealed that aqueous 3R4F smoke extract promoted the adhesion of MM6 cells to HCAECs via distinct direct and indirect concentration-dependent mechanisms. Using the same approach, we identified significantly reduced effects of aqueous THS2.2 aerosol extract on MM6 cell-HCAEC adhesion, and reduced molecular changes in endothelial and monocytic cells. Ten- and 20-fold increased concentrations of aqueous THS2.2 aerosol extract were necessary to elicit similar effects to those measured with 3R4F in both fresh direct and indirect exposure modalities, respectively. Our systems toxicology study demonstrated reduced effects of an aqueous aerosol extract from the candidate MRTP, THS2.2, using the adhesion of monocytic cells to human coronary endothelial cells as a surrogate pathophysiologically relevant event in atherogenesis. Copyright © 2015 Z. Published by Elsevier Ireland Ltd.. All rights reserved.

γ-Oryzanol reduces adhesion molecule expression in vascular endothelial cells via suppression of nuclear factor-κB activation.

PubMed

Sakai, Satoshi; Murata, Takahisa; Tsubosaka, Yoshiki; Ushio, Hideki; Hori, Masatoshi; Ozaki, Hiroshi

2012-04-04

γ-Oryzanol (γ-ORZ) is a mixture of phytosteryl ferulates purified from rice bran oil. In this study, we examined whether γ-ORZ represents a suppressive effect on the lipopolysaccharide (LPS)-induced adhesion molecule expression on vascular endothelium. Treatment with LPS elevated the mRNA expression of vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1), and E-selectin in bovine aortic endothelial cells (BAECs). Pretreatment with γ-ORZ dose-dependently decreased the LPS-mediated expression of these genes. Western blotting also revealed that pretreatment with γ-ORZ dose-dependently inhibited LPS-induced VCAM-1 expression in human umbilical vein endothelial cells. Consistently, pretreatment with γ-ORZ dose-dependently reduced LPS-induced U937 monocyte adhesion to BAECs. In immunofluorescence, LPS caused nuclear factor-κB (NF-κB) nuclear translocation in 40% of BAECs, which indicates NF-κB activation. Pretreatment with γ-ORZ, as well as its components (cycloartenyl ferulate, ferulic acid, or cycloartenol), dose-dependently inhibited LPS-mediated NF-κB activation. Collectively, our results suggested that γ-ORZ reduced LPS-mediated adhesion molecule expression through NF-κB inhibition in vascular endothelium.

Cell-cell and cell-extracellular matrix adhesions cooperate to organize actomyosin networks and maintain force transmission during dorsal closure.

PubMed

Goodwin, Katharine; Lostchuck, Emily E; Cramb, Kaitlyn M L; Zulueta-Coarasa, Teresa; Fernandez-Gonzalez, Rodrigo; Tanentzapf, Guy

2017-05-15

Tissue morphogenesis relies on the coordinated action of actin networks, cell-cell adhesions, and cell-extracellular matrix (ECM) adhesions. Such coordination can be achieved through cross-talk between cell-cell and cell-ECM adhesions. Drosophila dorsal closure (DC), a morphogenetic process in which an extraembryonic tissue called the amnioserosa contracts and ingresses to close a discontinuity in the dorsal epidermis of the embryo, requires both cell-cell and cell-ECM adhesions. However, whether the functions of these two types of adhesions are coordinated during DC is not known. Here we analyzed possible interdependence between cell-cell and cell-ECM adhesions during DC and its effect on the actomyosin network. We find that loss of cell-ECM adhesion results in aberrant distributions of cadherin-mediated adhesions and actin networks in the amnioserosa and subsequent disruption of myosin recruitment and dynamics. Moreover, loss of cell-cell adhesion caused up-regulation of cell-ECM adhesion, leading to reduced cell deformation and force transmission across amnioserosa cells. Our results show how interdependence between cell-cell and cell-ECM adhesions is important in regulating cell behaviors, force generation, and force transmission critical for tissue morphogenesis. © 2017 Goodwin, Lostchuck, et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

Inhibitory effects of OK-432 (Picibanil) on cellular proliferation and adhesive capacity of breast carcinoma cells.

PubMed

Horii, Yoshio; Iino, Yuichi; Maemura, Michio; Horiguchi, Jun; Morishita, Yasuo

2005-02-01

We investigated the potent inhibitory effects of OK-432 (Picibanil) on both cellular adhesion and cell proliferation of estrogen-dependent (MCF-7) or estrogen-independent (MDA-MB-231) breast carcinoma cells. Cellular proliferation of both MCF-7 and MDA-MB-231 cells was markedly inhibited in a dose-dependent manner, when the carcinoma cells were exposed to OK-432. Cell attachment assay demonstrated that incubation with OK-432 for 24 h reduced integrin-mediated cellular adhesion of both cell types. However, fluorescence activated cell sorter (FACS) analysis revealed that incubation with OK-432 for 24 h did not decrease the cell surface expressions of any integrins. These results suggest that the binding avidity of integrins is reduced by OK-432 without alteration of the integrin expression. We conclude that OK-432 inhibits integrin-mediated cellular adhesion as well as cell proliferation of breast carcinoma cells regardless of estrogen-dependence, and that these actions of OK-432 contribute to prevention or inhibition of breast carcinoma invasion and metastasis.

A Novel Assay for Easy and Rapid Quantification of Helicobacter pylori Adhesion.

PubMed

Skindersoe, Mette E; Rasmussen, Lone; Andersen, Leif P; Krogfelt, Karen A

2015-06-01

Reducing adhesion of Helicobacter pylori to gastric epithelial cells could be a new way to counteract infections with this organism. We here present a novel method for quantification of Helicobacter pylori adhesion to cells. Helicobacter pylori is allowed to adhere to AGS or MKN45g cells in a 96-well microtiter plate. Then wells are added saponin, which lyses the cells without affecting the bacteria. After addition of alamarBlue(®) (resazurin) and 1- to 2-hour incubation, fluorescence measurements can be used to quantify the number of adherent bacteria. By use of the method, we demonstrate that adhesion of both a sabA and babA deletion mutant of H. pylori is significantly reduced compared to the wild type. The method offers a number of applications and may be used to compare the adherence potential of different strains of H. pylori to either cells or different materials or to screen for potential anti-adhesive compounds. The results presented here suggest that this easy and reproducible assay is well suited for quantitative investigation of H. pylori adhesion. © 2015 John Wiley & Sons Ltd.

Surface grafting of a thermoplastic polyurethane with methacrylic acid by previous plasma surface activation and by ultraviolet irradiation to reduce cell adhesion.

PubMed

Alves, P; Pinto, S; Kaiser, Jean-Pierre; Bruinink, Arie; de Sousa, Hermínio C; Gil, M H

2011-02-01

The material performance, in a biological environment, is mainly mediated by its surface properties and by the combination of chemical, physical, biological, and mechanical properties required, for a specific application. In this study, the surface of a thermoplastic polyurethane (TPU) material (Elastollan(®)1180A50) was activated either by plasma or by ultra-violet (UV) irradiation. After surface activation, methacrylic acid (MAA) was linked to the surface of TPU in order to improve its reactivity and to reduce cell adhesion. Grafted surfaces were evaluated by X-ray photoelectron spectroscopy (XPS), by atomic force microscopy (AFM) and by contact angle measurements. Blood compatibility studies and cell adhesion tests with human bone marrow cells (HBMC) were also performed. If was found that UV grafting method led to better results than the plasma activation method, since cell adhesion was reduced when methacrylic acid was grafted to the TPU surface by UV. Copyright © 2010 Elsevier B.V. All rights reserved.

Annexin A6 contributes to the invasiveness of breast carcinoma cells by influencing the organization and localization of functional focal adhesions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sakwe, Amos M., E-mail: asakwe@mmc.edu; Koumangoye, Rainelli; Guillory, Bobby

2011-04-01

The interaction of annexin A6 (AnxA6) with membrane phospholipids and either specific extracellular matrix (ECM) components or F-actin suggests that it may influence cellular processes associated with rapid plasma membrane reorganization such as cell adhesion and motility. Here, we examined the putative roles of AnxA6 in adhesion-related cellular processes that contribute to breast cancer progression. We show that breast cancer cells secrete annexins via the exosomal pathway and that the secreted annexins are predominantly cell surface-associated. Depletion of AnxA6 in the invasive BT-549 breast cancer cells is accompanied by enhanced anchorage-independent cell growth but cell-cell cohesion, cell adhesion/spreading onto collagenmore » type IV or fetuin-A, cell motility and invasiveness were strongly inhibited. To explain the loss in adhesion/motility, we show that vinculin-based focal adhesions in the AnxA6-depleted BT-549 cells are elongated and randomly distributed. These focal contacts are also functionally defective because the activation of focal adhesion kinase and the phosphoinositide-3 kinase/Akt pathway were strongly inhibited while the MAP kinase pathway remained constitutively active. Compared with normal human breast tissues, reduced AnxA6 expression in breast carcinoma tissues correlates with enhanced cell proliferation. Together this suggests that reduced AnxA6 expression contributes to breast cancer progression by promoting the loss of functional cell-cell and/or cell-ECM contacts and anchorage-independent cell proliferation.« less

Salmonella enterica serovar Typhimurium adhesion and cytotoxicity during epithelial cell stress is reduced by Lactobacillus rhamnosus GG

PubMed Central

Burkholder, Kristin M; Bhunia, Arun K

2009-01-01

Background Physiological stressors may alter susceptibility of the host intestinal epithelium to infection by enteric pathogens. In the current study, cytotoxic effect, adhesion and invasion of Salmonella enterica serovar Typhimurium (S. Typhimurium) to Caco-2 cells exposed to thermal stress (41°C, 1 h) was investigated. Probiotic bacteria have been shown to reduce interaction of pathogens with the epithelium under non-stress conditions and may have a significant effect on epithelial viability during infection; however, probiotic effect on pathogen interaction with epithelial cells under physiological stress is not known. Therefore, we investigated the influence of Lactobacillus rhamnosus GG and Lactobacillus gasseri on Salmonella adhesion and Salmonella-induced cytotoxicity of Caco-2 cells subjected to thermal stress. Results Thermal stress increased the cytotoxic effect of both S. Typhimurium (P = 0.0001) and nonpathogenic E. coli K12 (P = 0.004) to Caco-2 cells, and resulted in greater susceptibility of cell monolayers to S. Typhimurium adhesion (P = 0.001). Thermal stress had no significant impact on inflammatory cytokines released by Caco-2 cells, although exposure to S. Typhimurium resulted in greater than 80% increase in production of IL-6 and IL-8. Blocking S. Typhimurium with anti-ShdA antibody prior to exposure of Salmonella decreased adhesion (P = 0.01) to non-stressed and thermal-stressed Caco-2 cells. Pre-exposure of Caco-2 cells to L. rhamnosus GG significantly reduced Salmonella-induced cytotoxicity (P = 0.001) and Salmonella adhesion (P = 0.001) to Caco-2 cells during thermal stress, while L. gasseri had no effect. Conclusion Results suggest that thermal stress increases susceptibility of intestinal epithelial Caco-2 cells to Salmonella adhesion, and increases the cytotoxic effect of Salmonella during infection. Use of L. rhamnosus GG as a probiotic may reduce the severity of infection during epithelial cell stress. Mechanisms by which thermal stress increases susceptibility to S. Typhimurium colonization and by which L. rhamnosus GG limits the severity of infection remain to be elucidated. PMID:19589170

Protopine inhibits heterotypic cell adhesion in MDA-MB-231 cells through down-regulation of multi-adhesive factors.

PubMed

He, Kai; Gao, Jian-Li

2014-01-01

A Chinese herb Corydalis yanhusuo W.T. Wang that showed anticancer and anti-angiogenesis effects in our previous studies was presented for further studies. In the present study, we studied the anticancer proliferation and adhesion effects of five alkaloids which were isolated from Corydalis yanhusuo. MTT dose response curves, cell migration assay, cell invasion assay, as well as three types of cell adhesive assay were performed on MDA-MB-231 human breast cancer cells. The mechanism of the compounds on inhibiting heterotypic cell adhesion were further explored by determining the expression of epidermal growth factor receptor (EGFR), Intercellular adhesion molecule 1 (ICAM-1), αv-integrin, β1-integrin and β5-integrin by western blotting assay. In five tested alkaloids, only protopine exhibited anti-adhesive and anti-invasion effects in MDA-MB-231 cells, which contributed to the anti-metastasis effect of Corydalis yanhusuo. The results showed that after treatment with protopine for 90 min, the expression of EGFR, ICAM-1, αv-integrin, β1-integrin and β5-integrin were remarkably reduced. The present results suggest that protopine seems to inhibit the heterotypic cell adhesion between MDA-MB-231 cells, and human umbilical vein endothelial cells by changing the expression of adhesive factors.

Phosphatase of regenerating liver-3 is expressed in acute lymphoblastic leukemia and mediates leukemic cell adhesion, migration and drug resistance

PubMed Central

Hjort, Magnus A.; Abdollahi, Pegah; Vandsemb, Esten N.; Fenstad, Mona H.; Lund, Bendik; Slørdahl, Tobias S.; Børset, Magne; Rø, Torstein B.

2018-01-01

Phosphatase of regenerating liver-3 (PRL-3/PTP4A3) is upregulated in multiple cancers, including BCR-ABL1- and ETV6-RUNX-positive acute lymphoblastic leukemia (ALL). With this study, we aim to characterize the biological role of PRL-3 in B cell ALL (B-ALL). Here, we demonstrate that PRL-3 expression at mRNA and protein level was higher in B-ALL cells than in normal cells, as measured by qRT-PCR or flow cytometry. Further, we demonstrate that inhibition of PRL-3 using shRNA or a small molecular inhibitor reduced cell migration towards an SDF-1α gradient in the preB-ALL cell lines Reh and MHH-CALL-4. Knockdown of PRL-3 also reduced cell adhesion towards fibronectin in Reh cells. Mechanistically, PRL-3 mediated SDF-1α stimulated calcium release, and activated focal adhesion kinase (FAK) and Src, important effectors of migration and adhesion. Finally, PRL-3 expression made Reh cells more resistance to cytarabine treatment. In conclusion, the expression level of PRL-3 was higher in B-ALL cells than in normal cells. PRL-3 promoted adhesion, migration and resistance to cytarabine. PRL-3 may represent a novel target in the treatment of B-ALL. PMID:29423065

Integration of actomyosin contractility with cell-cell adhesion during dorsal closure.

PubMed

Duque, Julia; Gorfinkiel, Nicole

2016-12-15

In this work, we combine genetic perturbation, time-lapse imaging and quantitative image analysis to investigate how pulsatile actomyosin contractility drives cell oscillations, apical cell contraction and tissue closure during morphogenesis of the amnioserosa, the main force-generating tissue during the dorsal closure in Drosophila We show that Myosin activity determines the oscillatory and contractile behaviour of amnioserosa cells. Reducing Myosin activity prevents cell shape oscillations and reduces cell contractility. By contrast, increasing Myosin activity increases the amplitude of cell shape oscillations and the time cells spend in the contracted phase relative to the expanded phase during an oscillatory cycle, promoting cell contractility and tissue closure. Furthermore, we show that in AS cells, Rok controls Myosin foci formation and Mbs regulates not only Myosin phosphorylation but also adhesion dynamics through control of Moesin phosphorylation, showing that Mbs coordinates actomyosin contractility with cell-cell adhesion during amnioserosa morphogenesis. © 2016. Published by The Company of Biologists Ltd.

[Study on the effect of phloretin on inhibiting malignant pheotype of BEL-7402 cells].

PubMed

Luo, Hui; Wang, Ya-Jun; Chen, Jie; Liu, Jiang-Qin

2008-07-01

To investigate the effect of phloretin on inhibiting BEL-7402 cells' growth, invasive, migration and adhesion ability and the rate of colony formation. BEL-7402 cells' growth, invasive, migration and adhesion ability and the rate of colony formation were examined with MIT method and Costar Transwell. Phloretin inhibited the growth, invasive, migration and adhesion ability of BEL-7402 cells and reduced the rate of colony formation in dose-dependent. Phloretin can inhibit BEL-7402 cells' malignant pheotype.

Polyethylene Glycol-Functionalized Magnetic Fe₃O₄/P(MMA-AA) Composite Nanoparticles Enhancing Efficient Capture of Circulating Tumor Cells.

PubMed

Ma, Shaohua; Zhan, Xiaohui; Yang, Minggang; Lan, Fang; Wu, Yao; Gu, Zhongwei

2018-04-01

Circulating tumor cells (CTCs) played a significant role in early diagnosis and prognosis of carcinomas, and efficient capture of CTCs was highly desired to provide important and reliable evidence for clinical diagnosis. In present work, we successfully synthesized functional magnetic Fe3O4/P(MMA-AA) composite nanoparticles (FCNPs) inspired by a counterbalance concept for recognition and capture of CTCs. This counterbalance, composed of polyethylene glycol (PEG) suppressing cell adhesion and anti-epithelial-cell-adhesion-molecule (anti-EpCAM) antibody targeting tumor cells, could both enhance the specific capture of tumor cells and reduce unspecific adhesion of normal cells. The study showed that the PEG density on the surface of the FCNPs affected the specificity of the materials, and a density of ca. 15% was efficient for reducing the unspecific adhesion. After incubation with the mixture of HepG2 cells and Jurkat T cells, the FCNPs reached a capture efficiency as high as about 86.5% of the cancer cells, suggesting great potential on detection of CTCs in the diagnoses and prognoses of cancer metastasis.

MHC Class II Activation and Interferon-γ Mediate the Inhibition of Neutrophils and Eosinophils by Staphylococcal Enterotoxin Type A (SEA).

PubMed

Ferreira-Duarte, Ana P; Pinheiro-Torres, Anelize S; Anhê, Gabriel F; Condino-Neto, Antônio; Antunes, Edson; DeSouza, Ivani A

2017-01-01

Staphylococcal enterotoxins are classified as superantigens that act by linking T-cell receptor with MHC class II molecules, which are expressed on classical antigen-presenting cells (APC). Evidence shows that MHC class II is also expressed in neutrophils and eosinophils. This study aimed to investigate the role of MHC class II and IFN-γ on chemotactic and adhesion properties of neutrophils and eosinophils after incubation with SEA. Bone marrow (BM) cells obtained from BALB/c mice were resuspended in culture medium, and incubated with SEA (3-30 ng/ml; 1-4 h), after which chemotaxis and adhesion were evaluated. Incubation with SEA significantly reduced the chemotactic and adhesive responses in BM neutrophils activated with IL-8 (200 ng/ml). Likewise, SEA significantly reduced the chemotactic and adhesive responses of BM eosinophils activated with eotaxin (300 ng/ml). The inhibitory effects of SEA on cell chemotaxis and adhesion were fully prevented by prior incubation with an anti-MHC class II blocking antibody (2 μg/ml). SEA also significantly reduced the intracellular Ca 2+ levels in IL-8- and eotaxin-activated BM cells. No alterations of MAC-1, VLA4, and LFA-1α expressions were observed after SEA incubation. In addition, SEA elevated by 3.5-fold ( P < 0.05) the INF-γ levels in BM cells. Incubation of BM leukocytes with IFN-γ (10 ng/ml, 2 h) reduced both neutrophil and eosinophil chemotaxis and adhesion, which were prevented by prior incubation with anti-MHC class II antibody (2 μg/ml). In conclusion, SEA inhibits neutrophil and eosinophil by MHC class II-dependent mechanism, which may be modulated by concomitant release of IFN-γ.

Application of nanosheets as an anti-adhesion barrier in partial hepatectomy.

PubMed

Niwa, Daisuke; Koide, Masatsugu; Fujie, Toshinori; Goda, Nobuhito; Takeoka, Shinji

2013-10-01

Postoperative adhesion often causes serious adverse effects such as bowl obstruction, chronic abdominal pain, pelvic pain, and infertility. We previously reported that a poly-L-lactic acid (PLLA) nanosheet can efficiently seal a surgical incision without scarring. In this report, we examined whether the PLLA nanosheet can form an effective anti-adhesion barrier in partial hepatectomy accompanied by severe hemorrhaging in rats. To evaluate the anti-adhesive property of the nanosheet, the liver wound surface was covered with TachoComb(®) , a well-known hemostat material used in clinical procedures, and then with the PLLA nanosheet. Dressing the wound surface with TachoComb(®) alone caused severe adhesion with omentum and/or residual parts of the liver. By contrast, combinational usage of TachoComb(®) and the PLLA nanosheet significantly reduced such adhesion, presumably by inhibiting the permeation of oozing blood cells and the infiltration of fibroblastic cells. Moreover, the nanosheet displayed low permeability against serum proteins as well as cells in vitro, supporting the notion that the PLLA nanosheet has anti-adhesive properties in vivo. These results strongly suggested that the PLLA nanosheet is a promising material for reducing unwanted postoperative adhesion. Copyright © 2013 Wiley Periodicals, Inc.

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

PubMed Central

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

2001-01-01

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

Physical confinement alters tumor cell adhesion and migration phenotypes

PubMed Central

Balzer, Eric M.; Tong, Ziqiu; Paul, Colin D.; Hung, Wei-Chien; Stroka, Kimberly M.; Boggs, Amanda E.; Martin, Stuart S.; Konstantopoulos, Konstantinos

2012-01-01

Cell migration on planar surfaces is driven by cycles of actin protrusion, integrin-mediated adhesion, and myosin-mediated contraction; however, this mechanism may not accurately describe movement in 3-dimensional (3D) space. By subjecting cells to restrictive 3D environments, we demonstrate that physical confinement constitutes a biophysical stimulus that alters cell morphology and suppresses mesenchymal motility in human breast carcinoma (MDA-MB-231). Dorsoventral polarity, stress fibers, and focal adhesions are markedly attenuated by confinement. Inhibitors of myosin, Rho/ROCK, or β1-integrins do not impair migration through 3-μm-wide channels (confinement), even though these treatments repress motility in 50-μm-wide channels (unconfined migration) by ≥50%. Strikingly, confined migration persists even when F-actin is disrupted, but depends largely on microtubule (MT) dynamics. Interfering with MT polymerization/depolymerization causes confined cells to undergo frequent directional changes, thereby reducing the average net displacement by ≥80% relative to vehicle controls. Live-cell EB1-GFP imaging reveals that confinement redirects MT polymerization toward the leading edge, where MTs continuously impact during advancement of the cell front. These results demonstrate that physical confinement can induce cytoskeletal alterations that reduce the dependence of migrating cells on adhesion-contraction force coupling. This mechanism may explain why integrins can exhibit reduced or altered function during migration in 3D environments.—Balzer, E. M., Tong, Z., Paul, C. D., Hung, W.-C., Stroka, K. M., Boggs, A. E., Martin, S. S., Konstantopoulos, K. Physical confinement alters tumor cell adhesion and migration phenotypes. PMID:22707566

Polystyrene-Divinylbenzene-Based Adsorbents Reduce Endothelial Activation and Monocyte Adhesion Under Septic Conditions in a Pore Size-Dependent Manner.

PubMed

Eichhorn, Tanja; Rauscher, Sabine; Hammer, Caroline; Gröger, Marion; Fischer, Michael B; Weber, Viktoria

2016-10-01

Endothelial activation with excessive recruitment and adhesion of immune cells plays a central role in the progression of sepsis. We established a microfluidic system to study the activation of human umbilical vein endothelial cells by conditioned medium containing plasma from lipopolysaccharide-stimulated whole blood or from septic blood and to investigate the effect of adsorption of inflammatory mediators on endothelial activation. Treatment of stimulated whole blood with polystyrene-divinylbenzene-based cytokine adsorbents (average pore sizes 15 or 30 nm) prior to passage over the endothelial layer resulted in significantly reduced endothelial cytokine and chemokine release, plasminogen activator inhibitor-1 secretion, adhesion molecule expression, and in diminished monocyte adhesion. Plasma samples from sepsis patients differed substantially in their potential to induce endothelial activation and monocyte adhesion despite their almost identical interleukin-6 and tumor necrosis factor-alpha levels. Pre-incubation of the plasma samples with a polystyrene-divinylbenzene-based adsorbent (30 nm average pore size) reduced endothelial intercellular adhesion molecule-1 expression to baseline levels, resulting in significantly diminished monocyte adhesion. Our data support the potential of porous polystyrene-divinylbenzene-based adsorbents to reduce endothelial activation under septic conditions by depletion of a broad range of inflammatory mediators.

Aggregatibacter actinomycetemcomitans regulates the expression of integrins and reduces cell adhesion via integrin α5 in human gingival epithelial cells.

PubMed

Kochi, Shinsuke; Yamashiro, Keisuke; Hongo, Shoichi; Yamamoto, Tadashi; Ugawa, Yuki; Shimoe, Masayuki; Kawamura, Mari; Hirata-Yoshihara, Chiaki; Ideguchi, Hidetaka; Maeda, Hiroshi; Takashiba, Shogo

2017-12-01

Gingival epithelial cells form a physiological barrier against bacterial invasion. Excessive bacterial invasion destroys the attachment between the tooth surface and the epithelium, resulting in periodontitis. Integrins play a significant role in cell attachment; therefore, we hypothesized that bacterial infection might decrease the expressions of these integrins in gingival epithelial cells, resulting in reduced cell adhesion. Immortalized human gingival epithelial cells were co-cultured with Aggregatibacter actinomycetemcomitans Y4 (Aa Y4), and the gene expression levels of IL-8, proliferating cell nuclear antigen (PCNA), and integrins (α2, α3, α5, β4, and β6) were measured using quantitative reverse transcription polymerase chain reaction. Expression of PCNA and integrins, except integrin α5, was significantly downregulated, while expression of IL-8 and integrin α5 was significantly upregulated in the cells co-cultured with Aa Y4. The number of adherent cells significantly decreased when co-cultured with Aa Y4, as determined using cell adhesion assays. In the cells co-cultured with Aa Y4 and an integrin α5 neutralizing antibody, there was no effect on the expression of IL-8 and PCNA, while the expressions of integrins α2, α3, β4, and β6, and the number of adherent cells did not decrease. The number of invading bacteria in the cells was reduced in the presence of the antibody and increased in the presence of TLR2/4 inhibitor. Therefore, integrin α5 might be involved in Aa Y4 invasion into gingival epithelial cells, and the resulting signal transduction cascade reduces cell adhesion by decreasing the expression of integrins, while the TLR2/4 signaling cascade regulates IL-8 expression.

Alpha-enolase on apical surface of renal tubular epithelial cells serves as a calcium oxalate crystal receptor

NASA Astrophysics Data System (ADS)

Fong-Ngern, Kedsarin; Thongboonkerd, Visith

2016-10-01

To search for a strategy to prevent kidney stone formation/recurrence, this study addressed the role of α-enolase on apical membrane of renal tubular cells in mediating calcium oxalate monohydrate (COM) crystal adhesion. Its presence on apical membrane and in COM crystal-bound fraction was confirmed by Western blotting and immunofluorescence staining. Pretreating MDCK cells with anti-α-enolase antibody, not isotype-controlled IgG, dramatically reduced cell-crystal adhesion. Immunofluorescence staining also confirmed the direct binding of purified α-enolase to COM crystals at {121} > {100} > {010} crystal faces. Coating COM crystals with urinary proteins diminished the crystal binding capacity to cells and purified α-enolase. Moreover, α-enolase selectively bound to COM, not other crystals. Chemico-protein interactions analysis revealed that α-enolase interacted directly with Ca2+ and Mg2+. Incubating the cells with Mg2+ prior to cell-crystal adhesion assay significantly reduced crystal binding on the cell surface, whereas preincubation with EDTA, a divalent cation chelator, completely abolished Mg2+ effect, indicating that COM and Mg2+ competitively bind to α-enolase. Taken together, we successfully confirmed the role of α-enolase as a COM crystal receptor to mediate COM crystal adhesion at apical membrane of renal tubular cells. It may also serve as a target for stone prevention by blocking cell-crystal adhesion and stone nidus formation.

The adhesion force of Notch with Delta and the rate of Notch signaling.

PubMed

Ahimou, Francois; Mok, Lee-Peng; Bardot, Boris; Wesley, Cedric

2004-12-20

Notch signaling is repeatedly used during animal development to specify cell fates. Using atomic force microscopy on live cells, chemical inhibitors, and conventional analyses, we show that the rate of Notch signaling is linked to the adhesion force between cells expressing Notch receptors and Delta ligand. Both the Notch extracellular and intracellular domains are required for the high adhesion force with Delta. This high adhesion force is lost within minutes, primarily due to the action of Presenilin on Notch. Reduced turnover or Delta pulling accelerate this loss. These data suggest that strong adhesion between Notch and Delta might serve as a booster for initiating Notch signaling at a high rate.

Inhibition of tumor necrosis factor-{alpha}-induced expression of adhesion molecules in human endothelial cells by the saponins derived from roots of Platycodon grandiflorum

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Ji Young; Kim, Dong Hee; Kim, Hyung Gyun

2006-01-15

Adhesion molecules play an important role in the development of atherogenesis and are produced by endothelial cells after being stimulated with various inflammatory cytokines. This study examined the effect of saponins that were isolated from the roots of Platycodon grandiflorum A. DC (Campanulaceae), Changkil saponins (CKS), on the cytokine-induced monocyte/human endothelial cell interaction, which is a crucial early event in atherogenesis. CKS significantly inhibited the TNF{alpha}-induced increase in monocyte adhesion to endothelial cells as well as decreased the protein and mRNA expression levels of vascular adhesion molecule-1 and intercellular cell adhesion molecule-1 on endothelial cells. Furthermore, CKS significantly inhibited themore » TNF{alpha}-induced production of intracellular reactive oxygen species (ROS) and activation of NF-{kappa}B by preventing I{kappa}B degradation and inhibiting I{kappa}B kinase activity. Overall, CKS has anti-atherosclerotic and anti-inflammatory activity, which is least in part the result of it reducing the cytokine-induced endothelial adhesion to monocytes by inhibiting intracellular ROS production, NF-{kappa}B activation, and cell adhesion molecule expression in endothelial cells.« less

Esculin and its oligomer fractions inhibit adhesion and migration of U87 glioblastoma cells and in vitro angiogenesis.

PubMed

Mokdad-Bzeouich, Imen; Kovacic, Hervé; Ghedira, Kamel; Chebil, Latifa; Ghoul, Mohamed; Chekir-Ghedira, Leila; Luis, José

2016-03-01

Cancer metastasis is the major cause of cancer-related death. Chemoprevention is defined as the use of natural or synthetic substances to prevent cancer formation or cancer progress. In the present study, we investigate the antitumor activity of esculin and its oligomer fractions in U87 glioblastoma cells. We showed that esculin and its oligomers reduced U87 cell growth in a dose dependent manner. They also inhibited cell adhesion to collagen IV and vitronectin by interfering with the function of their respective receptors α2β1 and αvβ5 integrins. Furthermore, the tested samples were able to reduce migration of U87 cells towards another extracellular matrix fibronectin. Moreover, esculin and its oligomer fractions inhibited in vitro angiogenesis of endothelial cells (HMEC-1). In summary, our data provide the first evidence that esculin and its oligomer fractions are able to reduce adhesion, migration of glioblastoma cells and in vitro angiogenesis. Esculin and its oligomers may thus exert multi-target functions against cancer cells.

Engagement of αIIbβ3 (GPIIb/IIIa) with ανβ3 Integrin Mediates Interaction of Melanoma Cells with Platelets

PubMed Central

Lonsdorf, Anke S.; Krämer, Björn F.; Fahrleitner, Manuela; Schönberger, Tanja; Gnerlich, Stephan; Ring, Sabine; Gehring, Sarah; Schneider, Stefan W.; Kruhlak, Michael J.; Meuth, Sven G.; Nieswandt, Bernhard; Gawaz, Meinrad; Enk, Alexander H.; Langer, Harald F.

2012-01-01

A mutual relationship exists between metastasizing tumor cells and components of the coagulation cascade. The exact mechanisms as to how platelets influence blood-borne metastasis, however, remain poorly understood. Here, we used murine B16 melanoma cells to observe functional aspects of how platelets contribute to the process of hematogenous metastasis. We found that platelets interfere with a distinct step of the metastasis cascade, as they promote adhesion of melanoma cells to the endothelium in vitro under shear conditions. Constitutively active platelet receptor GPIIb/IIIa (integrin αIIbβ3) expressed on Chinese hamster ovary cells promoted melanoma cell adhesion in the presence of fibrinogen, whereas blocking antibodies to aνβ3 integrin on melanoma cells or to GPIIb/IIIa significantly reduced melanoma cell adhesion to platelets. Furthermore, using intravital microscopy, we observed functional platelet-melanoma cell interactions, as platelet depletion resulted in significantly reduced melanoma cell adhesion to the injured vascular wall in vivo. Using a mouse model of hematogenous metastasis to the lung, we observed decreased metastasis of B16 melanoma cells to the lung by treatment with a mAb blocking the aν subunit of aνβ3 integrin. This effect was significantly reduced when platelets were depleted in vivo. Thus, the engagement of GPIIb/IIIa with aνβ3 integrin interaction mediates tumor cell-platelet interactions and highlights how this interaction is involved in hematogenous tumor metastasis. PMID:22102277

ZnO nanoparticle incorporated nanostructured metallic titanium for increased mesenchymal stem cell response and antibacterial activity

NASA Astrophysics Data System (ADS)

Elizabeth, Elmy; Baranwal, Gaurav; Krishnan, Amit G.; Menon, Deepthy; Nair, Manitha

2014-03-01

Recent trends in titanium implants are towards the development of nanoscale topographies that mimic the nanoscale properties of bone tissue. Although the nanosurface promotes the integration of osteoblast cells, infection related problems can also occur, leading to implant failure. Therefore it is imperative to reduce bacterial adhesion on an implant surface, either with or without the use of drugs/antibacterial agents. Herein, we have investigated two different aspects of Ti surfaces in inhibiting bacterial adhesion and concurrently promoting mammalian cell adhesion. These include (i) the type of nanoscale topography (Titania nanotube (TNT) and Titania nanoleaf (TNL)) and (ii) the presence of an antibacterial agent like zinc oxide nanoparticles (ZnOnp) on Ti nanosurfaces. To address this, periodically arranged TNT (80-120 nm) and non-periodically arranged TNL surfaces were generated by the anodization and hydrothermal techniques respectively, and incorporated with ZnOnp of different concentrations (375 μM, 750 μM, 1.125 mM and 1.5 mM). Interestingly, TNL surfaces decreased the adherence of staphylococcus aureus while increasing the adhesion and viability of human osteosarcoma MG63 cell line and human mesenchymal stem cells, even in the absence of ZnOnp. In contrast, TNT surfaces exhibited an increased bacterial and mammalian cell adhesion. The influence of ZnOnp on these surfaces in altering the bacterial and cell adhesion was found to be concentration dependent, with an optimal range of 375-750 μM. Above 750 μM, although bacterial adhesion was reduced, cellular viability was considerably affected. Thus our study helps us to infer that nanoscale topography by itself or its combination with an optimal concentration of antibacterial ZnOnp would provide a differential cell behavior and thereby a desirable biological response, facilitating the long term success of an implant.

Signal Regulatory Protein α Negatively Regulates β2 Integrin-Mediated Monocyte Adhesion, Transendothelial Migration and Phagocytosis

PubMed Central

Liu, Dan-Qing; Li, Li-Min; Guo, Ya-Lan; Bai, Rui; Wang, Chen; Bian, Zhen; Zhang, Chen-Yu; Zen, Ke

2008-01-01

Background Signal regulate protein α (SIRPα) is involved in many functional aspects of monocytes. Here we investigate the role of SIRPα in regulating β2 integrin-mediated monocyte adhesion, transendothelial migration (TEM) and phagocytosis. Methodology/Principal Findings THP-1 monocytes/macropahges treated with advanced glycation end products (AGEs) resulted in a decrease of SIRPα expression but an increase of β2 integrin cell surface expression and β2 integrin-mediated adhesion to tumor necrosis factor-α (TNFα)–stimulated human microvascular endothelial cell (HMEC-1) monolayers. In contrast, SIRPα overexpression in THP-1 cells showed a significant less monocyte chemotactic protein-1 (MCP-1)–triggered cell surface expression of β2 integrins, in particular CD11b/CD18. SIRPα overexpression reduced β2 integrin-mediated firm adhesion of THP-1 cells to either TNFα–stimulated HMEC-1 monolayers or to immobilized intercellular adhesion molecule-1 (ICAM-1). SIRPα overexpression also reduced MCP-1–initiated migration of THP-1 cells across TNFα–stimulated HMEC-1 monolayers. Furthermore, β2 integrin-mediated THP-1 cell spreading and actin polymerization in response to MCP-1, and phagocytosis of bacteria were both inhibited by SIRPα overexpression. Conclusions/Significance SIRPα negatively regulates β2 integrin-mediated monocyte adhesion, transendothelial migration and phagocytosis, thus may serve as a critical molecule in preventing excessive activation and accumulation of monocytes in the arterial wall during early stage of atherosclerosis. PMID:18820737

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gustafsson, Karin; Heffner, Garrett; Wenzel, Pamela L.

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. Despitemore » 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.« less

Perfluorocarbon induces alveolar epithelial cell response through structural and mechanical remodeling.

PubMed

André Dias, Sofia; Planus, Emmanuelle; Angely, Christelle; Lotteau, Luc; Tissier, Renaud; Filoche, Marcel; Louis, Bruno; Pelle, Gabriel; Isabey, Daniel

2018-02-15

During total liquid ventilation, lung cells are exposed to perfluorocarbon (PFC) whose chemophysical properties highly differ from standard aqueous cell feeding medium (DMEM). We herein perform a systematic study of structural and mechanical properties of A549 alveolar epithelial cells in order to characterize their response to PFC exposure, using DMEM as control condition. Changes in F-actin structure, focal adhesion density and glycocalyx distribution are evaluated by confocal fluorescent microscopy. Changes in cell mechanics and adhesion are measured by multiscale magnetic twisting cytometry (MTC). Two different microrheological models (single Voigt and power law) are used to analyze the cell mechanics characterized by cytoskeleton (CSK) stiffness and characteristic relaxation times. Cell-matrix adhesion is analyzed using a stochastic multibond deadhesion model taking into account the non-reversible character of the cell response, allowing us to quantify the adhesion weakness and the number of associated bonds. The roles of F-actin structure and glycocalyx layer are evaluated by depolymerizing F-actin and degrading glycocalyx, respectively. Results show that PFC exposure consistently induces F-actin remodeling, CSK softening and adhesion weakening. These results demonstrate that PFC triggers an alveolar epithelial cell response herein evidenced by a decay in intracellular CSK tension, an adhesion weakening and a glycocalyx layer redistribution. These PFC-induced cell adjustments are consistent with the hypothesis that cells respond to a decrease in adhesion energy at cell surface. This adhesion energy can be even further reduced in the presence of surfactant adsorbed at the cell surface.

Graphene oxide assisted synthesis of GaN nanostructures for reducing cell adhesion.

PubMed

Yang, Rong; Zhang, Ying; Li, Jingying; Han, Qiusen; Zhang, Wei; Lu, Chao; Yang, Yanlian; Dong, Hongwei; Wang, Chen

2013-11-21

We report a general approach for the synthesis of large-scale gallium nitride (GaN) nanostructures by the graphene oxide (GO) assisted chemical vapor deposition (CVD) method. A modulation effect of GaN nanostructures on cell adhesion has been observed. The morphology of the GaN surface can be controlled by GO concentrations. This approach, which is based on the predictable choice of the ratio of GO to catalysts, can be readily extended to the synthesis of other materials with controllable nanostructures. Cell studies show that GaN nanostructures reduced cell adhesion significantly compared to GaN flat surfaces. The cell-repelling property is related to the nanostructure and surface wettability. These observations of the modulation effect on cell behaviors suggest new opportunities for novel GaN nanomaterial-based biomedical devices. We believe that potential applications will emerge in the biomedical and biotechnological fields.

Membrane cholesterol plays an important role in enteropathogen adhesion and the activation of innate immunity via flagellin-TLR5 signaling.

PubMed

Zhou, Mingxu; Duan, Qiangde; Li, Yinchau; Yang, Yang; Hardwidge, Philip R; Zhu, Guoqiang

2015-08-01

Lipid rafts are cholesterol- and sphingolipid-rich ordered microdomains distributed in the plasma membrane that participates in mammalian signal transduction pathways. To determine the role of lipid rafts in mediating interactions between enteropathogens and intestinal epithelial cells, membrane cholesterol was depleted from Caco-2 and IPEC-J2 cells using methyl-β-cyclodextrin. Cholesterol depletion significantly reduced Escherichia coli and Salmonella enteritidis adhesion and invasion into intestinal epithelial cells. Complementation with exogenous cholesterol restored bacterial adhesion to basal levels. We also evaluated the role of lipid rafts in the activation of Toll-like receptor 5 signaling by bacterial flagellin. Depleting membrane cholesterol reduced the ability of purified recombinant E. coli flagellin to activate TLR5 signaling in intestinal cells. These data suggest that both membrane cholesterol and lipid rafts play important roles in enteropathogen adhesion and contribute to the activation of innate immunity via flagellin-TLR5 signaling.

Cellular and molecular mechanisms of pomegranate juice-induced anti-metastatic effect on prostate cancer cells.

PubMed

Wang, Lei; Alcon, Andre; Yuan, Hongwei; Ho, Jeffrey; Li, Qi-Jing; Martins-Green, M

2011-07-01

Prostate cancer is the second leading cause of cancer-related deaths among US males. Pomegranate juice (PJ), a natural product, was shown in a clinical trial to inhibit progression of this disease. However, the underlying mechanisms involved in the anti-progression effects of PJ on prostate cancer remain unclear. Here we show that, in addition to causing cell death of hormone-refractory prostate cancer cells, PJ also increases cell adhesion and decreases cell migration of the cells that do not die. We hypothesized that PJ does so by stimulating the expression and/or activation of molecules that alter the cytoskeleton and the adhesion machinery of prostate cancer cells, resulting in enhanced cell adhesion and reduced cell migration. We took an integrative approach to these studies by using Affimetrix gene arrays to study gene expression, microRNA arrays to study the non-coding RNAs, molecules known to be disregulated in cancer cells, and Luminex Multiplex array assays to study the level of secreted pro-inflammatory cytokines/chemokines. PJ up-regulates genes involved in cell adhesion such as E-cadherin, intercellular adhesion molecule 1 (ICAM-1) and down-regulates genes involved in cell migration such as hyaluranan-mediated motility receptor (HMMR) and type I collagen. In addition, anti-invasive microRNAs such as miR-335, miR-205, miR-200, and miR-126, were up-regulated, whereas pro-invasive microRNA such as miR-21 and miR-373, were down-regulated. Moreover, PJ significantly reduced the level of secreted pro-inflammatory cytokines/chemokines such as IL-6, IL-12p40, IL-1β and RANTES, thereby having the potential to decrease inflammation and its impact on cancer progression. PJ also inhibits the ability of the chemokine SDF1α to chemoattract these cancer cells. SDF1α and its receptor CXCR4 are important in metastasis of cancer cells to the bone. Discovery of the mechanisms by which this enhanced adhesion and reduced migration are accomplished can lead to sophisticated and effective prevention of metastasis in prostate and potentially other cancers. This journal is © The Royal Society of Chemistry 2011

Receptor-like Molecules on Human Intestinal Epithelial Cells Interact with an Adhesion Factor from Lactobacillus reuteri.

PubMed

Matsuo, Yosuke; Miyoshi, Yukihiro; Okada, Sanae; Satoh, Eiichi

2012-01-01

A surface protein of Lactobacillus reuteri, mucus adhesion-promoting protein (MapA), is considered to be an adhesion factor. MapA is expressed in L. reuteri strains and adheres to piglet gastric mucus, collagen type I, and human intestinal epithelial cells such as Caco-2. The aim of this study was to identify molecules that mediate the attachment of MapA from L. reuteri to the intestinal epithelial cell surface by investigating the adhesion of MapA to receptor-like molecules on Caco-2 cells. MapA-binding receptor-like molecules were detected in Caco-2 cell lysates by 2D-PAGE. Two proteins, annexin A13 (ANXA13) and paralemmin (PALM), were identified by MALDI TOF-MS. The results of a pull-down assay showed that MapA bound directly to ANXA13 and PALM. Fluorescence microscopy studies confirmed that MapA binding to ANXA13 and PALM was colocalized on the Caco-2 cell membrane. To evaluate whether ANXA13 and PALM are important for MapA adhesion, ANXA13 and PALM knockdown cell lines were established. The adhesion of MapA to the abovementioned cell lines was reduced compared with that to wild-type Caco-2 cells. These knockdown experiments established the importance of these receptor-like molecules in MapA adhesion.

Synergistic antitumor effect of combining metronomic chemotherapy with adoptive cell immunotherapy in nude mice.

PubMed

Shi, Shujing; Tao, Leilei; Song, Haizhu; Chen, Longbang; Huang, Guichun

2014-05-01

Adoptive cell immunotherapy with cytokine-induced killer cell (CIK cell) represents a promising non-toxic anticancer therapy. However, the clinical efficacy of CIK cells is limited because of abnormal tumor vasculature. Metronomic chemotherapy shows promising anticancer activity by its potential antiangiogenic effect and reduced toxicity. We hypothesized that metronomic chemotherapy with paclitaxel could improve the antitumor effect of adoptive CIK cell immunotherapy. Mice health status was analyzed by measuring mice weight and observing mice behavior. Immunohistochemistry was used to investigate the recruitment of CIK cells, the expression of endothelial cell molecules, as well as the hypoxic tumor area. Metronomic paclitaxel synergized with adoptive CIK cell immunotherapy to inhibit the growth of non-small cell lung cancer (NSCLC). Metronomic paclitaxel reduced hypoxic tumor area and increased CIK cell infiltration. Hypoxia impeded the adhesion of CIK cells and reduced the expression of endothelial cell adhesion molecules. In vivo studies demonstrated that more CIK cells were found in endothelial cell adhesion molecules high expressed area. Our study provides a new rationale for combining metronomic chemotherapy with adoptive cell immunotherapy in the treatment of xenograft NSCLC tumors in immunodeficient mice. Further clinical trials integrating translational research are necessary to better evaluate the clinical benefit of this promising approach. © 2014 APMIS. Published by John Wiley & Sons Ltd.

Inhibition of bacterial and leukocyte adhesion under shear stress conditions by material surface chemistry.

PubMed

Patel, Jasmine D; Ebert, Michael; Stokes, Ken; Ward, Robert; Anderson, James M

2003-01-01

Biomaterial-centered infections, initiated by bacterial adhesion, persist due to a compromised host immune response. Altering implant materials with surface modifying endgroups (SMEs) may enhance their biocompatibility by reducing bacterial and inflammatory cell adhesion. A rotating disc model, which generates shear stress within physiological ranges, was used to characterize adhesion of leukocytes and Staphylococcus epidermidis on polycarbonate-urethanes and polyetherurethanes modified with SMEs (polyethylene oxide, fluorocarbon and dimethylsiloxane) under dynamic flow conditions. Bacterial adhesion in the absence of serum was found to be mediated by shear stress and surface chemistry, with reduced adhesion exhibited on materials modified with polydimethylsiloxane and polyethylene oxide SMEs. In contrast, bacterial adhesion was enhanced on materials modified with fluorocarbon SMEs. In the presence of serum, bacterial adhesion was primarily neither material nor shear dependent. However, bacterial adhesion in serum was significantly reduced to < or = 10% compared to adhesion in serum-free media. Leukocyte adhesion in serum exhibited a shear dependency with increased adhesion occurring in regions exposed to lower shear-stress levels of < or = 7 dyne/cm2. Additionally, polydimethylsiloxane and polyethylene oxide SMEs reduced leukocyte adhesion on polyether-urethanes. In conclusion, these results suggest that surface chemistry and shear stress can mediate bacterial and cellular adhesion. Furthermore, materials modified with polyethylene oxide SMEs are capable of inhibiting bacterial adhesion, consequently minimizing the probability of biomaterial-centered infections.

Matrix MetalloProteinases (MMPs) andTissue Inhibitors of MetalloProteinases (TIMPs): positive and negative regulators intumor cell adhesion

PubMed Central

Bourboulia, Dimitra; Stetler-Stevenson, William G.

2010-01-01

Cells adhere to one another and/or to matrices that surround them. Regulation of cell-cell (intercellular) and cell-matrix adhesion is tightly controlled in normal cells, however, defects in cell adhesion are common in the majority of humancancers. Multilateral communication among tumor cells with the extracellular matrix (ECM) and neighbor cells is accomplished through adhesion molecules, ECM components, proteolytic enzymes and their endogenous inhibitors. There is sufficient evidence to suggest that reduced adherence is a tumor cell propertyengaged during tumor progression. Tumor cells acquire the ability to change shape, detach and easily move through spaces disorganizing the normal tissue architecture. This property is due to changes in expression levels of adhesion molecules and/or due to elevated levels of secreted proteolytic enzymes, including matrix metalloproteinases (MMPs). Among other roles, MMPsdegrade the ECMand, therefore, prepare the path for tumor cells to migrate, invade and spread to distant secondary areas, where they form metastasis. Tissue Inhibitors of Metalloproteinases or TIMPs control MMP activities and, therefore, minimize matrix degradation. Both MMPs and TIMPs are involved in tissue remodeling and decisively regulate tumor cell progression including tumor angiogenesis. In this review, we describe and discuss data that support the important role of MMPs and TIMPs in cancer cell adhesion and tumor progression. PMID:20470890

Structural Requirements for Outside-In and Inside-Out Signaling by Drosophila Neuroglian, a Member of the L1 Family of Cell Adhesion Molecules

PubMed Central

Hortsch, Michael; Homer, Diahann; Malhotra, Jyoti Dhar; Chang, Sherry; Frankel, Jason; Jefford, Gregory; Dubreuil, Ronald R.

1998-01-01

Expression of the Drosophila cell adhesion molecule neuroglian in S2 cells leads to cell aggregation and the intracellular recruitment of ankyrin to cell contact sites. We localized the region of neuroglian that interacts with ankyrin and investigated the mechanism that limits this interaction to cell contact sites. Yeast two-hybrid analysis and expression of neuroglian deletion constructs in S2 cells identified a conserved 36-amino acid sequence that is required for ankyrin binding. Mutation of a conserved tyrosine residue within this region reduced ankyrin binding and extracellular adhesion. However, residual recruitment of ankyrin by this mutant neuroglian molecule was still limited to cell contacts, indicating that the lack of ankyrin binding at noncontact sites is not caused by tyrosine phosphorylation. A chimeric molecule, in which the extracellular domain of neuroglian was replaced with the corresponding domain from the adhesion molecule fasciclin II, also selectively recruited ankyrin to cell contacts. Thus, outside-in signaling by neuroglian in S2 cells depends on extracellular adhesion, but does not depend on any unique property of its extracellular domain. We propose that the recruitment of ankyrin to cell contact sites depends on a physical rearrangement of neuroglian in response to cell adhesion, and that ankyrin binding plays a reciprocal role in stabilizing the adhesive interaction. PMID:9660878

Structural requirements for outside-in and inside-out signaling by Drosophila neuroglian, a member of the L1 family of cell adhesion molecules.

PubMed

Hortsch, M; Homer, D; Malhotra, J D; Chang, S; Frankel, J; Jefford, G; Dubreuil, R R

1998-07-13

Expression of the Drosophila cell adhesion molecule neuroglian in S2 cells leads to cell aggregation and the intracellular recruitment of ankyrin to cell contact sites. We localized the region of neuroglian that interacts with ankyrin and investigated the mechanism that limits this interaction to cell contact sites. Yeast two-hybrid analysis and expression of neuroglian deletion constructs in S2 cells identified a conserved 36-amino acid sequence that is required for ankyrin binding. Mutation of a conserved tyrosine residue within this region reduced ankyrin binding and extracellular adhesion. However, residual recruitment of ankyrin by this mutant neuroglian molecule was still limited to cell contacts, indicating that the lack of ankyrin binding at noncontact sites is not caused by tyrosine phosphorylation. A chimeric molecule, in which the extracellular domain of neuroglian was replaced with the corresponding domain from the adhesion molecule fasciclin II, also selectively recruited ankyrin to cell contacts. Thus, outside-in signaling by neuroglian in S2 cells depends on extracellular adhesion, but does not depend on any unique property of its extracellular domain. We propose that the recruitment of ankyrin to cell contact sites depends on a physical rearrangement of neuroglian in response to cell adhesion, and that ankyrin binding plays a reciprocal role in stabilizing the adhesive interaction.

6-Methylsulfinylhexyl isothiocyanate modulates endothelial cell function and suppresses leukocyte adhesion.

PubMed

Okamoto, Takayuki; Akita, Nobuyuki; Nagai, Masashi; Hayashi, Tatsuya; Suzuki, Koji

2014-01-01

6-Methylsulfinylhexyl isothiocyanate (6-MSITC) is an active compound in wasabi (Wasabia japonica Matsum.), which is one of the most popular spices in Japan. 6-MSITC suppresses lipopolysaccharide-induced macrophage activation, arachidonic- or adenosine diphosphate-induced platelet activation, and tumor cell proliferation. These data indicate that 6-MSITC has several biological activities involving anti-inflammatory, anti-coagulant, and anti-apoptosis properties. Endothelial cells (ECs) maintain vascular homeostasis and play crucial roles in crosstalk between blood coagulation and vascular inflammation. In this study, we determined the anti-coagulant and anti-inflammatory effects of 6-MSITC on human umbilical vein endothelial cells (HUVECs). 6-MSITC slightly reduced tissue factor expression, but did not alter von Willebrand factor release in activated HUVECs. 6-MSITC modulated the generation of activated protein C, which is essential for negative regulation of blood coagulation, on normal ECs. In addition, 6-MSITC reduced tumor necrosis factor-α (TNF-α)-induced interleukin-6 and monocyte chemoattractant protein-1 expression. 6-MSITC markedly attenuated TNF-α-induced adhesion of human monoblast U937 cells to HUVECs and reduced vascular cell adhesion molecule-1 and E-selectin mRNA expression in activated ECs. These results showed that 6-MSITC modulates EC function and suppresses cell adhesion. This study provides new insight into the mechanism of the anti-inflammatory effect of 6-MSITC, suggesting that 6-MSITC has therapeutic potential as a treatment for vasculitis and vascular inflammation.

A viscoelastic-stochastic model of the effects of cytoskeleton remodelling on cell adhesion.

PubMed

Li, Long; Zhang, Wenyan; Wang, Jizeng

2016-10-01

Cells can adapt their mechanical properties through cytoskeleton remodelling in response to external stimuli when the cells adhere to the extracellular matrix (ECM). Many studies have investigated the effects of cell and ECM elasticity on cell adhesion. However, experiments determined that cells are viscoelastic and exhibiting stress relaxation, and the mechanism behind the effect of cellular viscoelasticity on the cell adhesion behaviour remains unclear. Therefore, we propose a theoretical model of a cluster of ligand-receptor bonds between two dissimilar viscoelastic media subjected to an applied tensile load. In this model, the distribution of interfacial traction is assumed to follow classical continuum viscoelastic equations, whereas the rupture and rebinding of individual molecular bonds are governed by stochastic equations. On the basis of this model, we determined that viscosity can significantly increase the lifetime, stability and dynamic strength of the adhesion cluster of molecular bonds, because deformation relaxation attributed to the viscoelastic property can increase the rebinding probability of each open bond and reduce the stress concentration in the adhesion area.

Adhesion of Epstein–Barr virus-positive natural killer cell lines to cultured endothelial cells stimulated with inflammatory cytokines

PubMed Central

Kanno, H; Watabe, D; Shimizu, N; Sawai, T

2008-01-01

Chronic active Epstein–Barr virus (EBV) infection (CAEBV) is characterized by chronic recurrent infectious mononucleosis-like symptoms. Approximately one-fourth of CAEBV patients develop vascular lesions with infiltration of EBV-positive lymphoid cells. Furthermore, EBV-positive natural killer (NK)/T cell lymphomas often exhibit angiocentric or angiodestructive lesions. These suggest an affinity of EBV-positive NK/T cells to vascular components. In this study, we evaluated the expression of adhesion molecules and cytokines in EBV-positive NK lymphoma cell lines, SNK1 and SNK6, and examined the role of cytokines in the interaction between NK cell lines and endothelial cells. SNKs expressed intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) at much higher levels than those in EBV-negative T cell lines. SNKs produced the larger amount of tumour necrosis factor (TNF)-α, which caused increased expression of ICAM-1 and VCAM-1 in cultured human endothelial cells, than that from EBV-negative T cell lines. Furthermore, SNKs exhibited increased adhesion to cultured endothelial cells stimulated with TNF-α or interleukin (IL)-1β, and the pretreatment of cytokine-stimulated endothelial cells with anti-VCAM-1-antibodies reduced cell adhesion. These indicate that the up-regulated expression of VCAM-1 on cytokine-stimulated endothelial cells would be important for the adhesion of EBV-positive NK cells and might initiate the vascular lesions. PMID:18190605

Suppressor of cytokine signalling (SOCS) 1 and 3 enhance cell adhesion and inhibit migration towards the chemokine eotaxin/CCL11.

PubMed

Stevenson, Nigel J; McFarlane, Cheryl; Ong, Seow Theng; Nahlik, Krystyna; Kelvin, Alyson; Addley, Mark R; Long, Aideen; Greaves, David R; O'Farrelly, Cliona; Johnston, James A

2010-11-05

Suppressors of cytokine signalling (SOCS) proteins regulate signal transduction, but their role in responses to chemokines remains poorly understood. We report that cells expressing SOCS1 and 3 exhibit enhanced adhesion and reduced migration towards the chemokine CCL11. Focal adhesion kinase (FAK) and the GTPase RhoA, control cell adhesion and migration and we show the presence of SOCS1 or 3 regulates expression and tyrosine phosphorylation of FAK, while also enhancing activation of RhoA. Our novel findings suggest that SOCS1 and 3 may control chemotaxis and adhesion by significantly enhancing both FAK and RhoA activity, thus localizing immune cells to the site of allergic inflammation. Copyright © 2010 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

Cytohesin 1 regulates homing and engraftment of human hematopoietic stem and progenitor cells.

PubMed

Rak, Justyna; Foster, Katie; Potrzebowska, Katarzyna; Talkhoncheh, Mehrnaz Safaee; Miharada, Natsumi; Komorowska, Karolina; Torngren, Therese; Kvist, Anders; Borg, Åke; Svensson, Lena; Bonnet, Dominique; Larsson, Jonas

2017-02-23

Adhesion is a key component of hematopoietic stem cell regulation mediating homing and retention to the niche in the bone marrow. Here, using an RNA interference screen, we identify cytohesin 1 (CYTH1) as a critical mediator of adhesive properties in primary human cord blood-derived hematopoietic stem and progenitor cells (HSPCs). Knockdown of CYTH1 disrupted adhesion of HSPCs to primary human mesenchymal stroma cells. Attachment to fibronectin and ICAM1, 2 integrin ligands, was severely impaired, and CYTH1-deficient cells showed a reduced integrin β1 activation response, suggesting that CYTH1 mediates integrin-dependent functions. Transplantation of CYTH1-knockdown cells to immunodeficient mice resulted in significantly lower long-term engraftment levels, associated with a reduced capacity of the transplanted cells to home to the bone marrow. Intravital microscopy showed that CYTH1 deficiency profoundly affects HSPC mobility and localization within the marrow space and thereby impairs proper lodgment into the niche. Thus, CYTH1 is a novel major regulator of adhesion and engraftment in human HSPCs through mechanisms that, at least in part, involve the activation of integrins. © 2017 by The American Society of Hematology.

Edaravone attenuates monocyte adhesion to endothelial cells induced by oxidized low-density lipoprotein

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Zhijuan, E-mail: zjlee038@163.com; Cheng, Jianxin; Wang, Liping

2015-10-30

Oxidized low-density lipoprotein (oxLDL) plays a vital role in recruitment of monocytes to endothelial cells, which is important during early stages of atherosclerosis development. Edaravone, a potent and novel scavenger of free radicals inhibiting hydroxyl radicals, has been clinically used to reduce the neuronal damage following ischemic stroke. In the present study, Edaravone was revealed to markedly reduce oxLDL-induced monocyte adhesion to human umbilical vein endothelial cells (HUVECs). The inhibitory mechanism of Edaravone was associated with suppression of the chemokine MCP-1 and adhesion molecule VCAM-1 and ICAM-1 expression. In addition, luciferase reporter assay results revealed that administration of Edaravone attenuatedmore » the increase in NF-κB transcriptional activity induced by oxLDL. Notably, it's also shown that Edaravone treatment blocked oxLDL induced p65 nuclear translocation in HUVECs. Results indicate that Edaravone negatively regulates endothelial inflammation. - Highlights: • Edaravone reduces oxLDL-induced monocyte adhesion to HUVECs. • Edaravone attenuates oxLDL-induced expression of MCP-1, VCAM-1, and ICAM-1. • Edaravone reduces NF-κB transcriptional activity and p65 nuclear translocation.« less

CD151-mediated adhesion is crucial to osteosarcoma pulmonary metastasis

PubMed Central

Sun, Mengxiong; Zhou, Chenghao; Chen, Jian; Yin, Fei; Wang, Hongsheng; Lin, Binhui; Zuo, Dongqing; Li, Suoyuan; Feng, Lijin; Duan, Zhenfeng; Cai, Zhengdong; Hua, Yingqi

2016-01-01

CD151, a tetraspanin family protein involved in cell-cell and cell-extracellular matrix interaction, is differentially expressed in osteosarcoma cell membranes. Thus, this study aimed to investigate the role of CD151 in osteosarcoma metastasis. We analyzed CD151 expression in patient tissue samples using immunohistochemistry. CD151 expression was also silenced with shRNA in osteosarcoma cells of high metastatic potential, and cell adhesion, migration and invasion were evaluated in vitro and pulmonary metastasis was investigated in vivo. Mediators of cell signaling pathways were also examined following suppression of CD151 expression. Overall survival for patients with low versus high CD151 expression level was 94 vs. 41 months (p=0.0451). CD151 expression in osteosarcoma cells with high metastatic potential was significantly higher than in those with low metastatic potential (p<0.001). shRNA-mediated silencing of CD151 did not influence cell viability or proliferation; however, cell adhesion, migration and invasion were all inhibited (all p<0.001). In mice inoculated with shRNA-transduced osteosarcoma cells, the number and size of lung metastatic lesions were reduced compared to the mice inoculated with control-shRNA transduced cells (p<0.001). In addition, CD151 knockdown significantly reduced Akt, p38, and p65 phosphorylation as well as focal adhesion kinase, integrin β1, p70s6, and p-mTOR levels. Taken together, CD151 induced osteosarcoma metastasis likely by regulating cell function through adhesion signaling. Further studies are necessary to fully explore the diagnostic and prognostic value of determining CD151 expression in osteosarcoma patients. PMID:27556355

Osteoblast adhesion to orthopaedic implant alloys: Effects of cell adhesion molecules and diamond-like carbon coating

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kornu, R.; Kelly, M.A.; Smith, R.L.

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%more » (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.« less

Inhibition of STAT3 phosphorylation by sulforaphane reduces adhesion molecule expression in vascular endothelial cell.

PubMed

Cho, Young S; Kim, Chan H; Ha, Tae S; Ahn, Hee Y

2015-11-18

Intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1) play key roles in the initiation of vascular inflammation. In this study, we explored whether sulforaphane, a dietary phytochemical, can inhibit the expression of ICAM-1 and VCAM-1 in human umbilical vein endothelial cells (HUVEC) stimulated with lipopolysaccharide (LPS), and the mechanisms involved. Sulforaphane prevented the LPS-mediated increase in ICAM-1 and VCAM-1 expression, (P < 0.01) in HUVEC. Sulforaphane also prevented the LPS-mediated increase in the phosphorylation of signal transducer and activator of transcription 3 (STAT3) (P < 0.01). Stattic, a STAT3 inhibitor, reduced the LPS-induced expression of ICAM-1 and VCAM-1, and STAT3 phosphorylation (P < 0.01). STAT3 small interfering RNA treatment reduced the LPS-induced expression of ICAM-1, VCAM-1, and STAT3 (P < 0.01). Sulforaphane reduced LPS-mediated THP-1 monocyte adhesion to HUVEC (P < 0.01). In C57BL/6 mice, injection of LPS increased aortic ICAM-1 and VCAM-1 expression, and this effect was prevented by sulforaphane. These data provide insight into the mechanism through which sulforaphane partly reduces the expression of ICAM-1 and VCAM-1 on the vascular wall by inhibiting STAT3 phosphorylation.

The Anti-Atherosclerotic Effect of Naringin Is Associated with Reduced Expressions of Cell Adhesion Molecules and Chemokines through NF-κB Pathway.

PubMed

Hsueh, Tun-Pin; Sheen, Jer-Ming; Pang, Jong-Hwei S; Bi, Kuo-Wei; Huang, Chao-Chun; Wu, Hsiao-Ting; Huang, Sheng-Teng

2016-02-05

Naringin has been reported to have an anti-atherosclerosis effect but the underlying mechanism is not fully understood. The aim of this study is to investigate the impact of naringin on the TNF-α-induced expressions of cell adhesion molecules, chemokines and NF-κB signaling pathway in human umbilical vein endothelial cells (HUVECs). The experiments revealed that naringin, at concentrations without cytotoxicity, dose-dependently inhibited the adhesion of THP-1 monocytes to the TNF-α-stimulated HUVECs. The TNF-α-induced expressions of cell adhesion molecules, including VCAM-1, ICAM-1 and E-selectin, at both the mRNA and protein levels, were significantly suppressed by naringin in a dose dependent manner. In addition, the TNF-α-induced mRNA and protein levels of chemokines, including fractalkine/CX3CL1, MCP-1 and RANTES, were also reduced by naringin. Naringin significantly inhibited TNF-α-induced nuclear translocation of NF-κB, which resulted from the inhibited phosphorylation of IKKα/β, IκB-α and NF-κB. Altogether, we proposed that naringin modulated TNF-α-induced expressions of cell adhesion molecules and chemokines through the inhibition of TNF-α-induced activation of IKK/NF-κB signaling pathway to exert the anti-atherosclerotic effect.

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

PubMed Central

Nishitani, Wagner Shin; Alencar, Adriano Mesquita; Wang, Yingxiao

2015-01-01

A cell mechanical stimulation equipment, based on cell substrate deformation, and a more sensitive method for measuring adhesion of cells were developed. A probe, precisely positioned close to the cell, was capable of a vertical localized mechanical stimulation with a temporal frequency of 207 Hz, and strain magnitude of 50%. This setup was characterized and used to probe the response of Human Umbilical Endothelial Vein Cells (HUVECs) in terms of calcium signaling. The intracellular calcium ion concentration was measured by the genetically encoded Cameleon biosensor, with the Transient Receptor Potential cation channel, subfamily M, member 7 (TRPM7) expression inhibited. As TRPM7 expression also regulates adhesion, a relatively simple method for measuring adhesion of cells was also developed, tested and used to study the effect of adhesion alone. Three adhesion conditions of HUVECs on polyacrylamide gel dishes were compared. In the first condition, the substrate is fully treated with Sulfo-SANPAH crosslinking and fibronectin. The other two conditions had increasingly reduced adhesion: partially treated (only coated with fibronectin, with no use of Sulfo-SANPAH, at 5% of the normal amount) and non-treated polyacrylamide gels. The cells showed adhesion and calcium response to the mechanical stimulation correlated to the degree of gel treatment: highest for fully treated gels and lowest for non-treated ones. TRPM7 inhibition by siRNA on HUVECs caused an increase in adhesion relative to control (no siRNA treatment) and non-targeting siRNA, but a decrease to 80% of calcium response relative to non-targeting siRNA which confirms the important role of TRPM7 in mechanotransduction despite the increase in adhesion. PMID:25946314

Preventing the activation or cycling of the Rap1 GTPase alters adhesion and cytoskeletal dynamics and blocks metastatic melanoma cell extravasation into the lungs.

PubMed

Freeman, Spencer A; McLeod, Sarah J; Dukowski, Janet; Austin, Pamela; Lee, Crystal C Y; Millen-Martin, Brandie; Kubes, Paul; McCafferty, Donna-Marie; Gold, Michael R; Roskelley, Calvin D

2010-06-01

The Rap1 GTPase is a master regulator of cell adhesion, polarity, and migration. We show that both blocking Rap1 activation and expressing a constitutively active form of Rap1 reduced the ability of B16F1 melanoma cells to extravasate from the microvasculature and form metastatic lesions in the lungs. This correlated with a decreased ability of the tumor cells to undergo transendothelial migration (TEM) in vitro and form dynamic, F-actin-rich pseudopodia that penetrate capillary endothelial walls in vivo. Using multiple tumor cell lines, we show that the inability to form these membrane protrusions, which likely promote TEM and extravasation, can be explained by altered adhesion dynamics and impaired cell polarization that result when Rap1 activation or cycling is perturbed. Thus, targeting Rap1 could be a useful approach for reducing the metastatic dissemination of tumor cells that undergo active TEM. Copyright 2010 AACR.

Distinct Fcγ receptors mediate the effect of Serum Amyloid P on neutrophil adhesion and fibrocyte differentiation

PubMed Central

Cox, Nehemiah; Pilling, Darrell; Gomer, Richard H.

2014-01-01

The plasma protein Serum Amyloid P (SAP) reduces neutrophil adhesion, inhibits the differentiation of monocytes into fibroblast-like cells called fibrocytes, and promotes phagocytosis of cell debris by macrophages. Together, these effects of SAP reduce key aspects of inflammation and fibrosis, and SAP injections improve lung function in pulmonary fibrosis patients. SAP functions are mediated in part by Fcγ receptors, but the contribution of each Fcγ receptor is not fully understood. We found that amino acids Q55 and E126 in human SAP affect human fibrocyte differentiation and SAP binding to FcγRI. E126, K130 and Q128 affect neutrophil adhesion and SAP affinity for FcγRIIa. Q128 also affects phagocytosis by macrophages and SAP affinity for FcγRI. All the identified functionally significant amino acids in SAP form a binding site that is distinct from the previously described SAP-FcγRIIa binding site. Blocking FcγRI with an IgG blocking antibody reduces the SAP effect on fibrocyte differentiation, and ligating FcγRIIa with antibodies reduces neutrophil adhesion. Together, these results suggest that SAP binds to FcγRI on monocytes to inhibit fibrocyte differentiation, and binds to FcγRIIa on neutrophils to reduce neutrophil adhesion. PMID:25024390

Suspension state increases reattachment of breast cancer cells by up-regulating lamin A/C.

PubMed

Zhang, Xiaomei; Lv, Yonggang

2017-12-01

Extravasation is a rate-limiting step of tumor metastasis, for which adhesion to endothelium of circulating tumor cells (CTCs) is the prerequisite. The suspension state of CTCs undergoing detachment from primary tumor is a persistent biomechanical cue, which potentially regulates the biophysical characteristics and cellular behaviors of tumor cells. In this study, breast tumor cells MDA-MB-231 in suspension culture condition were used to investigate the effect of suspension state on reattachment of CTCs. Our study demonstrated that suspension state significantly increased the adhesion ability of breast tumor cells. In addition, suspension state markedly promoted the formation of stress fibers and focal adhesions and reduced the motility in reattached breast cancer cells. Moreover, lamin A/C was reversibly accumulated at posttranscriptional level under suspension state, improving the cell stiffness of reattached breast cancer cells. Disruption of actin cytoskeleton by cytochalasin D caused lamin A/C accumulation. Conversely, decreasing actomyosin contraction by ROCK inhibitor Y27632 reduced lamin A/C level. Knocking down lamin A/C weakened the suspension-induced increase of adhesion, and also abolished the suspension-induced decrease of motility and increase of stress fibers and focal adhesion in reattaching tumor cells, suggesting a crucial role of lamin A/C. In conclusion, it was demonstrated that suspension state promoted the reattachment of breast tumor cells by up-regulating lamin A/C via cytoskeleton disruption. These findings highlight the important role of suspension state for tumor cells in tumor metastasis. Copyright © 2017 Elsevier B.V. All rights reserved.

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

PubMed Central

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

1996-01-01

1. Leukocyte-endothelial cell interactions play an important role during ischaemia-reperfusion events. Adhesion molecules are specifically implicated in this interaction process. 2. Since defibrotide has been shown to be an efficient drug in reducing damage due to ischaemia-reperfusion in many experimental models, we analysed the effect of defibrotide in vitro on leukocyte adhesion to endothelial cells in basal conditions and after their stimulation. 3. In basal conditions, defibrotide (1000 micrograms ml-1) partially inhibited leukocyte adhesion to endothelial cells by 17.3% +/- 3.6 (P < 0.05), and after endothelial cell stimulation (TNF-alpha, 500 u ml-1) or after leukocyte stimulation (fMLP, 10(-7) M), it inhibited leukocyte adhesion by 26.5% +/- 3.4 and 32.4% +/- 1.8, respectively (P < 0.05). 4. In adhesion blockage experiments, the use of the monoclonal antibody anti-CD31 (5 micrograms ml-1) did not demonstrate a significant inhibitory effect whereas use of the monoclonal antibody anti-LFA-1 (5 micrograms ml-1) significantly interfered with the effect of defibrotide. 5. This result was confirmed in NIH/3T3-ICAM-1 transfected cells. 6. We conclude that defibrotide is able to interfere with leukocyte adhesion to endothelial cells mainly in activated conditions and that the ICAM-1/LFA-1 adhesion system is involved in the defibrotide mechanism of action. PMID:8762067

Desmoglein 3 regulates membrane trafficking of cadherins, an implication in cell-cell adhesion.

PubMed

Moftah, Hanan; Dias, Kasuni; Apu, Ehsanul Hoque; Liu, Li; Uttagomol, Jutamas; Bergmeier, Lesley; Kermorgant, Stephanie; Wan, Hong

2017-05-04

E-cadherin mediated cell-cell adhesion plays a critical role in epithelial cell polarization and morphogenesis. Our recent studies suggest that the desmosomal cadherin, desmoglein 3 (Dsg3) cross talks with E-cadherin and regulates its adhesive function in differentiating keratinocytes. However, the underlying mechanism remains not fully elucidated. Since E-cadherin trafficking has been recognized to be a central determinant in cell-cell adhesion and homeostasis we hypothesize that Dsg3 may play a role in regulating E-cadherin trafficking and hence the cell-cell adhesion. Here we investigated this hypothesis in cells with loss of Dsg3 function through RNAi mediated Dsg3 knockdown or the stable expression of the truncated mutant Dsg3ΔC. Our results showed that loss of Dsg3 resulted in compromised cell-cell adhesion and reduction of adherens junction and desmosome protein expression as well as the cortical F-actin formation. As a consequence, cells failed to polarize but instead displayed aberrant cell flattening. Furthermore, retardation of E-cadherin internalization and recycling was consistently observed in these cells during the process of calcium induced junction assembling. In contrast, enhanced cadherin endocytosis was detected in cells with overexpression of Dsg3 compared to control cells. Importantly, this altered cadherin trafficking was found to be coincided with the reduced expression and activity of Rab proteins, including Rab5, Rab7 and Rab11 which are known to be involved in E-cadherin trafficking. Taken together, our findings suggest that Dsg3 functions as a key in cell-cell adhesion through at least a mechanism of regulating E-cadherin membrane trafficking.

The effects of nitric oxide in settlement and adhesion of zoospores of the green alga Ulva.

PubMed

Thompson, Stephanie E M; Callow, Maureen E; Callow, James A

2010-01-01

Previous studies have shown that elevated nitric oxide (NO) reduces adhesion in diatom, bacterial and animal cells. This article reports experiments designed to investigate whether elevated NO reduces the adhesion of zoospores of the green alga Ulva, an important fouling species. Surface-normalised values of NO were measured using the fluorescent indicator DAF-FM DA and parallel hydrodynamic measurements of adhesion strength were made. Elevated levels of NO caused by the addition of the exogenous NO donor SNAP reduced spore settlement by 20% and resulted in lower adhesion strength. Addition of the NO scavenger cPTIO abolished the effects of SNAP on adhesion. The strength of attachment and NO production by spores in response to four coatings (Silastic T2; Intersleek 700; Intersleek 900 and polyurethane) shows that reduced adhesion is correlated with an increase in NO production. It is proposed that in spores of Ulva, NO is used as an intracellular signalling molecule to detect how conducive a surface is for settlement and adhesion. The effect of NO on the adhesion of a range of organisms suggests that NO-releasing coatings could have the potential to control fouling.

Activation of GPR4 by Acidosis Increases Endothelial Cell Adhesion through the cAMP/Epac Pathway

PubMed Central

Leffler, Nancy R.; Asch, Adam S.; Witte, Owen N.; Yang, Li V.

2011-01-01

Endothelium-leukocyte interaction is critical for inflammatory responses. Whereas the tissue microenvironments are often acidic at inflammatory sites, the mechanisms by which cells respond to acidosis are not well understood. Using molecular, cellular and biochemical approaches, we demonstrate that activation of GPR4, a proton-sensing G protein-coupled receptor, by isocapnic acidosis increases the adhesiveness of human umbilical vein endothelial cells (HUVECs) that express GPR4 endogenously. Acidosis in combination with GPR4 overexpression further augments HUVEC adhesion with U937 monocytes. In contrast, overexpression of a G protein signaling-defective DRY motif mutant (R115A) of GPR4 does not elicit any increase of HUVEC adhesion, indicating the requirement of G protein signaling. Downregulation of GPR4 expression by RNA interference reduces the acidosis-induced HUVEC adhesion. To delineate downstream pathways, we show that inhibition of adenylate cyclase by inhibitors, 2′,5′-dideoxyadenosine (DDA) or SQ 22536, attenuates acidosis/GPR4-induced HUVEC adhesion. Consistently, treatment with a cAMP analog or a Gi signaling inhibitor increases HUVEC adhesiveness, suggesting a role of the Gs/cAMP signaling in this process. We further show that the cAMP downstream effector Epac is important for acidosis/GPR4-induced cell adhesion. Moreover, activation of GPR4 by acidosis increases the expression of vascular adhesion molecules E-selectin, VCAM-1 and ICAM-1, which are functionally involved in acidosis/GPR4-mediated HUVEC adhesion. Similarly, hypercapnic acidosis can also activate GPR4 to stimulate HUVEC adhesion molecule expression and adhesiveness. These results suggest that acidosis/GPR4 signaling regulates endothelial cell adhesion mainly through the Gs/cAMP/Epac pathway and may play a role in the inflammatory response of vascular endothelial cells. PMID:22110680

Bioactive coating with low-fouling polymers for the development of biocompatible vascular implants

NASA Astrophysics Data System (ADS)

Thalla, Pradeep Kumar

The replacement of occluded blood vessels and endovascular aneurysm repair (EVAR) are performed with the use of synthetic vascular grafts and stent grafts, respectively. Both implants lead to frequent clinical complications that are different but due to a similar problem, namely the inadequate surface properties of the polymeric biomaterials used (generally polyethylene terephthalate (PET) or expanded polytetrafluoroethylene (ePTFE)). Therefore the general objective of this thesis was to create a versatile bioactive coating on vascular biomaterials that reduce material-induced thrombosis and promote desired cell interactions favorable to tissue healing around implants. The use of low-fouling backgrounds was decided in order to reduce platelet adhesion as well as the non-specific protein adsorption and thus increase the bioactivity of immobilized biomolecules. As part of the preliminary objective, a multi-arm polyethylene glycol (PEG) was chosen to create a versatile low-fouling surface, since the current coating methods are far from being versatile and rely on the availability of compatible functional groups on both PEG and the host surface. This PEG coating method was developed by taking advantage of novel primary amine-rich plasma polymerized coatings (LP). As demonstrated by quartz crystal microbalance with dissipation (QCM-D), fluorescence measurements and platelet adhesion assays, our PEG coatings exhibited low protein adsorption and almost no platelet adhesion after 15 min perfusion in whole blood. Although protein adsorption was not completely abrogated and short-term platelet adhesion assay was clearly insufficient to draw conclusions for long-term prevention of thrombosis in vivo, the low-fouling properties of this PEG coating were sufficient to be exploited for further coupling of bioactive molecules to create bioactive coatings. Therefore, as a part of the second objective, an innovative and versatile bioactive coating was developed on PEG and carboxymethylated dextran (CMD), using the combination of an adhesive peptide (KQAGDV/RGD) and epidermal growth factor (EGF). CMD was chosen as an alternative to PEG due to its better low-fouling properties and the presence of abundant carboxyl terminal groups. Although the QCM-D technique enabled us to optimize the combined immobilization of KQAGDV/RGD and EGF, cell adhesion assay results did not show improvement of vascular smooth muscle cell (VSMC) adhesion on peptide-modified PEG or CMD surfaces. Among the reasons explaining low cell adhesion on peptides grafted low-fouling surfaces is the difficulty of preventing protein adsorption/platelet adhesion without significantly reducing cell adhesion. Preliminary data in our laboratory indicated that CS could be an ideal substrate to find this compromise. For that reason, the final objective of this PhD consisted in evaluating the potential of chondroitin sulfate (CS) coating by comparing its properties with well-known low-fouling polymers such as PEG and CMD. It was shown that CS presents selective low-fouling properties, low-platelet adhesion and pro-endothelial cell (EC) adhesive properties As demonstrated by QCM-D and fluorescence measurements, CS was as effective as PEG in reducing fibrinogen adsorption, but it reduced adsorption of bovine serum albumin (BSA) and fetal bovine serum (FBS) to a lower extent than PEG and CMD surfaces. Whole blood perfusion assays indicated that all three surfaces drastically decreased platelet adhesion and activation to levels significantly lower than PET surfaces. However, while EC adhesion and growth were found to be very limited on PEG and CMD, cell attachment on CS was strong, with focal adhesion points and resistance to shear stress. CS coatings therefore form a low-thrombogenic background promoting the formation of a confluent endothelium layer, which may then act as an active anti-thrombogenic surface. CS coating can also be used to further graft biomolecules. Combination of LP, CS coating followed by GF immobilization shows great promise as a bioactive coating to optimize the biocompatibility and clinical outcome of vascular implants, in particular vascular grafts.

Receptor-like Molecules on Human Intestinal Epithelial Cells Interact with an Adhesion Factor from Lactobacillus reuteri

PubMed Central

MATSUO, Yosuke; MIYOSHI, Yukihiro; OKADA, Sanae; SATOH, Eiichi

2012-01-01

A surface protein of Lactobacillus reuteri, mucus adhesion-promoting protein (MapA), is considered to be an adhesion factor. MapA is expressed in L. reuteri strains and adheres to piglet gastric mucus, collagen type I, and human intestinal epithelial cells such as Caco-2. The aim of this study was to identify molecules that mediate the attachment of MapA from L. reuteri to the intestinal epithelial cell surface by investigating the adhesion of MapA to receptor-like molecules on Caco-2 cells. MapA-binding receptor-like molecules were detected in Caco-2 cell lysates by 2D-PAGE. Two proteins, annexin A13 (ANXA13) and paralemmin (PALM), were identified by MALDI TOF-MS. The results of a pull-down assay showed that MapA bound directly to ANXA13 and PALM. Fluorescence microscopy studies confirmed that MapA binding to ANXA13 and PALM was colocalized on the Caco-2 cell membrane. To evaluate whether ANXA13 and PALM are important for MapA adhesion, ANXA13 and PALM knockdown cell lines were established. The adhesion of MapA to the abovementioned cell lines was reduced compared with that to wild-type Caco-2 cells. These knockdown experiments established the importance of these receptor-like molecules in MapA adhesion. PMID:24936355

Impact of the exopolysaccharide layer on biofilms, adhesion and resistance to stress in Lactobacillus johnsonii FI9785.

PubMed

Dertli, Enes; Mayer, Melinda J; Narbad, Arjan

2015-02-04

The bacterial cell surface is a crucial factor in cell-cell and cell-host interactions. Lactobacillus johnsonii FI9785 produces an exopolysaccharide (EPS) layer whose quantity and composition is altered in mutants that harbour genetic changes in their eps gene clusters. We have assessed the effect of changes in EPS production on cell surface characteristics that may affect the ability of L. johnsonii to colonise the poultry host and exclude pathogens. Analysis of physicochemical cell surface characteristics reflected by Zeta potential and adhesion to hexadecane showed that an increase in EPS gave a less negative, more hydrophilic surface and reduced autoaggregation. Autoaggregation was significantly higher in mutants that have reduced EPS, indicating that EPS can mask surface structures responsible for cell-cell interactions. EPS also affected biofilm formation, but here the quantity of EPS produced was not the only determinant. A reduction in EPS production increased bacterial adhesion to chicken gut explants, but made the bacteria less able to survive some stresses. This study showed that manipulation of EPS production in L. johnsonii FI9785 can affect properties which may improve its performance as a competitive exclusion agent, but that positive changes in adhesion may be compromised by a reduction in the ability to survive stress.

Dynamin2 controls Rap1 activation and integrin clustering in human T lymphocyte adhesion

PubMed Central

Eppler, Felix J.

2017-01-01

Leukocyte trafficking is crucial to facilitate efficient immune responses. Here, we report that the large GTPase dynamin2, which is generally considered to have a key role in endocytosis and membrane remodeling, is an essential regulator of integrin-dependent human T lymphocyte adhesion and migration. Chemical inhibition or knockdown of dynamin2 expression significantly reduced integrin-dependent T cell adhesion in vitro. This phenotype was not observed when T cells were treated with various chemical inhibitors which abrogate endocytosis or actin polymerization. We furthermore detected dynamin2 in signaling complexes and propose that it controls T cell adhesion via FAK/Pyk2- and RapGEF1-mediated Rap1 activation. In addition, the dynamin2 inhibitor-induced reduction of lymphocyte adhesion can be rescued by Rap1a overexpression. We demonstrate that the dynamin2 effect on T cell adhesion does not involve integrin affinity regulation but instead relies on its ability to modulate integrin valency. Taken together, we suggest a previously unidentified role of dynamin2 in the regulation of integrin-mediated lymphocyte adhesion via a Rap1 signaling pathway. PMID:28273099

Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs): Positive and negative regulators in tumor cell adhesion.

PubMed

Bourboulia, Dimitra; Stetler-Stevenson, William G

2010-06-01

Cells adhere to one another and/or to matrices that surround them. Regulation of cell-cell (intercellular) and cell-matrix adhesion is tightly controlled in normal cells, however, defects in cell adhesion are common in the majority of human cancers. Multilateral communication among tumor cells with the extracellular matrix (ECM) and neighbor cells is accomplished through adhesion molecules, ECM components, proteolytic enzymes and their endogenous inhibitors. There is sufficient evidence to suggest that reduced adherence is a tumor cell property engaged during tumor progression. Tumor cells acquire the ability to change shape, detach and easily move through spaces disorganizing the normal tissue architecture. This property is due to changes in expression levels of adhesion molecules and/or due to elevated levels of secreted proteolytic enzymes, including matrix metalloproteinases (MMPs). Among other roles, MMPs degrade the ECM and, therefore, prepare the path for tumor cells to migrate, invade and spread to distant secondary areas, where they form metastasis. Tissue inhibitors of metalloproteinases or TIMPs control MMP activities and, therefore, minimize matrix degradation. Both MMPs and TIMPs are involved in tissue remodeling and decisively regulate tumor cell progression including tumor angiogenesis. In this review, we describe and discuss data that support the important role of MMPs and TIMPs in cancer cell adhesion and tumor progression. Published by Elsevier Ltd.

LL37 and hBD-3 elevate the β-1,3-exoglucanase activity of Candida albicans Xog1p, resulting in reduced fungal adhesion to plastic.

PubMed

Chang, Hao-Teng; Tsai, Pei-Wen; Huang, Hsin-Hui; Liu, Yu-Shu; Chien, Tzu-Shan; Lan, Chung-Yu

2012-02-01

The opportunistic fungus Candida albicans causes oral thrush and vaginal candidiasis, as well as candidaemia in immunocompromised patients including those undergoing cancer chemotherapy, organ transplant and those with AIDS. We previously found that the AMPs (antimicrobial peptides) LL37 and hBD-3 (human β-defensin-3) inhibited C. albicans viability and its adhesion to plastic. For the present study, the mechanism by which LL37 and hBD-3 reduced C. albicans adhesion was investigated. After AMP treatment, C. albicans adhesion to plastic was reduced by up to ~60% and was dose-dependent. Our previous study indicated that LL37 might interact with the cell-wall β-1,3-exoglucanase Xog1p, which is involved in cell-wall β-glucan metabolism, and consequently the binding of LL37 or hBD-3 to Xog1p might cause the decrease in adhesion. For the present study, Xog1p(41-438)-6H, an N-terminally truncated, active, recombinant construct of Xog1p and Xog1p fragments were produced and used in pull-down assays and ELISA in vitro, which demonstrated that all constructs interacted with both AMPs. Enzymatic analyses showed that LL37 and hBD-3 enhanced the β-1,3-exoglucanase activity of Xog1p(41-438)-6H approximately 2-fold. Therefore elevated Xog1p activity might compromise cell-wall integrity and decrease C. albicans adhesion. To test this hypothesis, C. albicans was treated with 1.3 μM Xog1p(41-438)-6H and C. albicans adhesion to plastic decreased 47.7%. Taken together, the evidence suggests that Xog1p is one of the LL37/hBD-3 targets, and elevated β-1,3-exoglucanase activity reduces C. albicans adhesion to plastic.

Anthocyanins and their gut metabolites reduce the adhesion of monocyte to TNFα-activated endothelial cells at physiologically relevant concentrations.

PubMed

Krga, Irena; Monfoulet, Laurent-Emmanuel; Konic-Ristic, Aleksandra; Mercier, Sylvie; Glibetic, Maria; Morand, Christine; Milenkovic, Dragan

2016-06-01

An increasing number of evidence suggests a protective role of dietary anthocyanins against cardiovascular diseases. Anthocyanins' extensive metabolism indicates that their metabolites could be responsible for the protective effects associated with consumption of anthocyanin-rich foods. The aim of this work was to investigate the effect of plasma anthocyanins and their metabolites on the adhesion of monocytes to TNFα-activated endothelial cells and on the expression of genes encoding cell adhesion molecules. Human umbilical vein endothelial cells (HUVECs) were exposed to circulating anthocyanins: cyanidin-3-arabinoside, cyanidin-3-galactoside, cyanidin-3-glucoside, delphinidin-3-glucoside, peonidin-3-glucoside, anthocyanin degradation product: 4-hydroxybenzaldehyde, or to their gut metabolites: protocatechuic, vanillic, ferulic and hippuric acid, at physiologically-relevant concentrations (0.1-2 μM) and time of exposure. Both anthocyanins and gut metabolites decreased the adhesion of monocytes to HUVECs, with a magnitude ranging from 18.1% to 47%. The mixture of anthocyanins and that of gut metabolites also reduced monocyte adhesion. However, no significant effect on the expression of genes encoding E-selectin, ICAM1 and VCAM1 was observed, suggesting that other molecular targets are involved in the observed effect. In conclusion, this study showed the potency of anthocyanins and their gut metabolites to modulate the adhesion of monocytes to endothelial cells, the initial step in atherosclerosis development, under physiologically-relevant conditions. Copyright © 2016 Elsevier Inc. All rights reserved.

[Effect of Golgi α-mannosidase 2 (GM2) gene knockdown on adhesion abilities of human gastric carcinoma cell line BGC-823 and its mechanism].

PubMed

Zeng, Bo; Zeng, Zhen; Liu, Chang; Yang, Yaying

2017-06-01

Objective To investigate the effect of Golgi α-mannosidase II (GM2) gene knockdown on adhesion abilities of BGC-823 human gastric carcinoma cells. Methods Three plasmid vectors expressing GM2 shRNAs and a negative control plasmid vector were designed, constructed and then transfected into BGC-823 cells by Lipofectamine TM 2000. After transfection, the mRNA and protein levels of GM2 in BGC-823 cells were detected by real-time quantitative PCR (qRT-PCR) and Western blotting to evaluate the transfection efficacy. The best plasmid for GM2 gene knockdown was selected and stably transfected into BGC-823 cells. Adhesion abilities of BGC-823 cells after GM2 gene silencing were observed by cell-cell, cell-matrix and cell-endothelial cell adhesion assays. At the same time, the expressions of E-cadherin, P-selectin, CD44v6 and intercellular adhesion molecule-1 (ICAM-1) proteins were detected by Western blotting after GM2 gene knockdown. Results The expression of GM2 was effectively knockdown in GM2-shRNA-2-transfected BGC-823 cells. Compared with the blank control group and the negative control group, the intercellular adhesion ability of the GM2-shRNA-2-transfected cells increased significantly, while their cell-matrix and cell-endothelium adhesion abilities markedly decreased. In GM2-shRNA-2 transfection group, E-cadherin expression was significantly elevated and the P-selectin expression was significantly reduced, while the expression levels of CD44v6 and ICAM-1 were not obviously changed. Conclusion After GM2 gene knockdown, the intercellular adhesion ability of gastric carcinoma BGC-823 cells is enhanced, while the adhesion abilities with the extracellular matrix and endothelial cells are weakened. The changes might be related to the up-regulated expression of E-cadherin and the down-regulation of P-selectin.

Novel mode of action of the calcium antagonist mibefradil (Ro 40-5967): potent immunosuppression by inhibition of T-cell infiltration through allogeneic endothelium.

PubMed Central

Blaheta, R A; Hailer, N P; Brude, N; Wittig, B; Oppermann, E; Leckel, K; Harder, S; Scholz, M; Weber, S; Encke, A; Markus, B H

1998-01-01

Cyclosporin A reduces the mitotic activity of allosensitized lymphocytes, but fails to limit emigration of these cells into the donor organ. However, the modulation of both lymphocyte proliferation and infiltration are desirable characteristics of immunosuppressive therapy. The calcium-channel blocker, verapamil, has recently been shown to effectively prevent the transmigration of CD4+ and CD8+ T cells through allogeneic endothelium. Mibefradil (Ro 40-5967) represents a new generation of calcium antagonists with high potency and long-term activity. To evaluate the immunosuppressive potential of this drug, the influence of mibefradil on lymphocyte adhesion to, horizontal locomotion along, and penetration through allogeneic endothelium (HUVEC) was performed. When lymphocytes were prestimulated for 24 hr with mibefradil, adhesion and penetration were dose-dependently reduced. The adhesion ID50 values were 3.4 microM (CD4+ T cells) versus 9.2 microM (CD8+ T cells) and 2.1 microM (CD4+ T cells) versus 3.9 microM (CD8+ T cells) with regard to penetration. Mibefradil also effectively blocked horizontal locomotion. Specific down-regulation of T-cell binding to the P-selection receptor (ID50: CD4+ T cells, 0.8 microM: CD8+ T cells, 1.2 microM) and to the intracellular adhesion molecule-1 (ICAM-1) receptor (ID50: CD4+ T cells, 1.9 microM; CD8+ T cells, 1.5 microM) by mibefradil seems to be responsible for the decreased adhesion and penetration rates. Reduction of intracellular F-actin in T lymphocytes could diminish cell locomotion. In conclusion, the potent suppressive properties of mibefradil support its use as a co-medication in cyclosporin A-based immunosuppressive therapy. PMID:9741343

Novel mode of action of the calcium antagonist mibefradil (Ro 40-5967): potent immunosuppression by inhibition of T-cell infiltration through allogeneic endothelium.

PubMed

Blaheta, R A; Hailer, N P; Brude, N; Wittig, B; Oppermann, E; Leckel, K; Harder, S; Scholz, M; Weber, S; Encke, A; Markus, B H

1998-06-01

Cyclosporin A reduces the mitotic activity of allosensitized lymphocytes, but fails to limit emigration of these cells into the donor organ. However, the modulation of both lymphocyte proliferation and infiltration are desirable characteristics of immunosuppressive therapy. The calcium-channel blocker, verapamil, has recently been shown to effectively prevent the transmigration of CD4+ and CD8+ T cells through allogeneic endothelium. Mibefradil (Ro 40-5967) represents a new generation of calcium antagonists with high potency and long-term activity. To evaluate the immunosuppressive potential of this drug, the influence of mibefradil on lymphocyte adhesion to, horizontal locomotion along, and penetration through allogeneic endothelium (HUVEC) was performed. When lymphocytes were prestimulated for 24 hr with mibefradil, adhesion and penetration were dose-dependently reduced. The adhesion ID50 values were 3.4 microM (CD4+ T cells) versus 9.2 microM (CD8+ T cells) and 2.1 microM (CD4+ T cells) versus 3.9 microM (CD8+ T cells) with regard to penetration. Mibefradil also effectively blocked horizontal locomotion. Specific down-regulation of T-cell binding to the P-selection receptor (ID50: CD4+ T cells, 0.8 microM: CD8+ T cells, 1.2 microM) and to the intracellular adhesion molecule-1 (ICAM-1) receptor (ID50: CD4+ T cells, 1.9 microM; CD8+ T cells, 1.5 microM) by mibefradil seems to be responsible for the decreased adhesion and penetration rates. Reduction of intracellular F-actin in T lymphocytes could diminish cell locomotion. In conclusion, the potent suppressive properties of mibefradil support its use as a co-medication in cyclosporin A-based immunosuppressive therapy.

Glucocorticoid-induced tumor necrosis factor receptor family-related ligand triggering upregulates vascular cell adhesion molecule-1 and intercellular adhesion molecule-1 and promotes leukocyte adhesion.

PubMed

Lacal, Pedro Miguel; Petrillo, Maria Grazia; Ruffini, Federica; Muzi, Alessia; Bianchini, Rodolfo; Ronchetti, Simona; Migliorati, Graziella; Riccardi, Carlo; Graziani, Grazia; Nocentini, Giuseppe

2013-10-01

The interaction of glucocorticoid-induced tumor necrosis factor receptor-family related (GITR) protein with its ligand (GITRL) modulates different functions, including immune/inflammatory response. These effects are consequent to intracellular signals activated by both GITR and GITRL. Previous results have suggested that lack of GITR expression in GITR(-/-) mice decreases the number of leukocytes within inflamed tissues. We performed experiments to analyze whether the GITRL/GITR system modulates leukocyte adhesion and extravasation. For that purpose, we first evaluated the capability of murine splenocytes to adhere to endothelial cells (EC). Our results indicated that adhesion of GITR(-/-) splenocytes to EC was reduced as compared with wild-type cells, suggesting that GITR plays a role in adhesion and that this effect may be due to GITRL-GITR interaction. Moreover, adhesion was increased when EC were pretreated with an agonist GITR-Fc fusion protein, thus indicating that triggering of GITRL plays a role in adhesion by EC regulation. In a human in vitro model, the adhesion to human EC of HL-60 cells differentiated toward the monocytic lineage was increased by EC pretreatment with agonist GITR-Fc. Conversely, antagonistic anti-GITR and anti-GITRL Ab decreased adhesion, thus further indicating that GITRL triggering increases the EC capability to support leukocyte adhesion. EC treatment with GITR-Fc favored extravasation, as demonstrated by a transmigration assay. Notably, GITRL triggering increased intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) expression and anti-ICAM-1 and anti-VCAM-1 Abs reversed GITR-Fc effects. Our study demonstrates that GITRL triggering in EC increases leukocyte adhesion and transmigration, suggesting new anti-inflammatory therapeutic approaches based on inhibition of GITRL-GITR interaction.

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

PubMed Central

Zahran, R.; Rosales Leal, J. I.; Rodríguez Valverde, M. A.; Cabrerizo Vílchez, M. A.

2016-01-01

Titanium implant surface etching has proven an effective method to enhance cell attachment. Despite the frequent use of hydrofluoric (HF) acid, many questions remain unresolved, including the optimal etching time and its effect on surface and biological properties. The objective of this study was to investigate the effect of HF acid etching time on Ti topography, surface chemistry, wettability, and cell adhesion. These data are useful to design improved acid treatment and obtain an improved cell response. The surface topography, chemistry, dynamic wetting, and cell adhesiveness of polished Ti surfaces were evaluated after treatment with HF acid solution for 0, 2; 3, 5, 7, or 10 min, revealing a time-dependent effect of HF acid on their topography, chemistry, and wetting. Roughness and wetting increased with longer etching time except at 10 min, when roughness increased but wetness decreased. Skewness became negative after etching and kurtosis tended to 3 with longer etching time. Highest cell adhesion was achieved after 5–7 min of etching time. Wetting and cell adhesion were reduced on the highly rough surfaces obtained after 10-min etching time. PMID:27824875

A viscoelastic–stochastic model of the effects of cytoskeleton remodelling on cell adhesion

PubMed Central

Li, Long; Zhang, Wenyan

2016-01-01

Cells can adapt their mechanical properties through cytoskeleton remodelling in response to external stimuli when the cells adhere to the extracellular matrix (ECM). Many studies have investigated the effects of cell and ECM elasticity on cell adhesion. However, experiments determined that cells are viscoelastic and exhibiting stress relaxation, and the mechanism behind the effect of cellular viscoelasticity on the cell adhesion behaviour remains unclear. Therefore, we propose a theoretical model of a cluster of ligand–receptor bonds between two dissimilar viscoelastic media subjected to an applied tensile load. In this model, the distribution of interfacial traction is assumed to follow classical continuum viscoelastic equations, whereas the rupture and rebinding of individual molecular bonds are governed by stochastic equations. On the basis of this model, we determined that viscosity can significantly increase the lifetime, stability and dynamic strength of the adhesion cluster of molecular bonds, because deformation relaxation attributed to the viscoelastic property can increase the rebinding probability of each open bond and reduce the stress concentration in the adhesion area. PMID:27853571

Force loading explains spatial sensing of ligands by cells

NASA Astrophysics Data System (ADS)

Oria, Roger; Wiegand, Tina; Escribano, Jorge; Elosegui-Artola, Alberto; Uriarte, Juan Jose; Moreno-Pulido, Cristian; Platzman, Ilia; Delcanale, Pietro; Albertazzi, Lorenzo; Navajas, Daniel; Trepat, Xavier; García-Aznar, José Manuel; Cavalcanti-Adam, Elisabetta Ada; Roca-Cusachs, Pere

2017-12-01

Cells can sense the density and distribution of extracellular matrix (ECM) molecules by means of individual integrin proteins and larger, integrin-containing adhesion complexes within the cell membrane. This spatial sensing drives cellular activity in a variety of normal and pathological contexts. Previous studies of cells on rigid glass surfaces have shown that spatial sensing of ECM ligands takes place at the nanometre scale, with integrin clustering and subsequent formation of focal adhesions impaired when single integrin-ligand bonds are separated by more than a few tens of nanometres. It has thus been suggested that a crosslinking ‘adaptor’ protein of this size might connect integrins to the actin cytoskeleton, acting as a molecular ruler that senses ligand spacing directly. Here, we develop gels whose rigidity and nanometre-scale distribution of ECM ligands can be controlled and altered. We find that increasing the spacing between ligands promotes the growth of focal adhesions on low-rigidity substrates, but leads to adhesion collapse on more-rigid substrates. Furthermore, disordering the ligand distribution drastically increases adhesion growth, but reduces the rigidity threshold for adhesion collapse. The growth and collapse of focal adhesions are mirrored by, respectively, the nuclear or cytosolic localization of the transcriptional regulator protein YAP. We explain these findings not through direct sensing of ligand spacing, but by using an expanded computational molecular-clutch model, in which individual integrin-ECM bonds—the molecular clutches—respond to force loading by recruiting extra integrins, up to a maximum value. This generates more clutches, redistributing the overall force among them, and reducing the force loading per clutch. At high rigidity and high ligand spacing, maximum recruitment is reached, preventing further force redistribution and leading to adhesion collapse. Measurements of cellular traction forces and actin flow speeds support our model. Our results provide a general framework for how cells sense spatial and physical information at the nanoscale, precisely tuning the range of conditions at which they form adhesions and activate transcriptional regulation.

A model study of factors involved in adhesion of Pseudomonas fluorescens to meat.

PubMed Central

Piette, J P; Idziak, E S

1992-01-01

A study was undertaken to investigate the factors involved in the adhesion of Pseudomonas fluorescens to model meat surfaces (tendon slices). Adhesion was fast (less than 2.5 min) and was not suppressed by killing the cells with UV, gamma rays, or heat, indicating that physiological activity was not required. In various salt solutions (NaCl, KCl, CaCl2, MgCl2), adhesion increased with increasing ionic strength up to 10 to 100 mM, suggesting that, at low ionic strengths, electrostatic interactions were involved in the adhesion process. At higher ionic strengths (greater than 10 to 100 mM) or in the presence of Al3+ ions, adhesion was sharply reduced. Selectively blocking of carboxyl or amino groups at the cell surface by chemical means did not affect adhesion. These groups are therefore not directly involved in an adhesive bond with tendon. Given a sufficient cell concentration (10(10) CFU.ml-1) in the adhesion medium, the surface of tendon was almost entirely covered with adherent bacteria. This suggests that if the adhesion is specific, the attachment sites on the tendon surface must be located within collagen or proteoglycan molecules. Images PMID:1444387

Estradiol, tamoxifen and ICI 182,780 alter alpha3 and beta1 integrin expression and laminin-1 adhesion in oral squamous cell carcinoma cell cultures.

PubMed

Nelson, Katja; Helmstaedter, Victor; Moreau, Cynthia; Lage, Hermann

2008-01-01

Adhesion molecules such as integrins and extracellular matrix proteins like laminins have been identified to play an important role in cell proliferation, migration and invasion by regulating cell-extracellular matrix interaction in various cancers including oral squamous cell carcinoma (OSCC). In this study, the effect of estradiol (E2), and the E2 antagonists tamoxifen (TAM) and ICI 182,780 (ICI) on the expression of integrins and adhesion to laminin-1 in different OSCC in vitro models was analyzed. TAM and ICI inhibited growth in all OSCC cell lines. Dependent on estrogen receptor (ER) status E2 displayed a significant influence on growth after long-term administration. ICI reduced laminin-1 adhesion in all cell lines. beta1 Integrin transcription is reduced with TAM and E2 and alpha3 cell surface expression with TAM. This study shows that OSCC is estrogen and SERM sensitive and that these compounds can modulate cell-matrix interaction in part by modulating integrin expression and translation. The investigation also confirms that growth is significantly influenced by these adjuvant therapeutics. These data suggest that a greater understanding of basic biology and mechanisms of the ER and its ligands in oral squamous cells is needed to elucidate the use of specific pharmacological agents as therapeutics of anti-tumorigenic pathways.

NAD+ Biosynthesis Ameliorates a Zebrafish Model of Muscular Dystrophy

PubMed Central

Goody, Michelle F.; Kelly, Meghan W.; Reynolds, Christine J.; Khalil, Andre; Crawford, Bryan D.; Henry, Clarissa A.

2012-01-01

Muscular dystrophies are common, currently incurable diseases. A subset of dystrophies result from genetic disruptions in complexes that attach muscle fibers to their surrounding extracellular matrix microenvironment. Cell-matrix adhesions are exquisite sensors of physiological conditions and mediate responses that allow cells to adapt to changing conditions. Thus, one approach towards finding targets for future therapeutic applications is to identify cell adhesion pathways that mediate these dynamic, adaptive responses in vivo. We find that nicotinamide riboside kinase 2b-mediated NAD+ biosynthesis, which functions as a small molecule agonist of muscle fiber-extracellular matrix adhesion, corrects dystrophic phenotypes in zebrafish lacking either a primary component of the dystrophin-glycoprotein complex or integrin alpha7. Exogenous NAD+ or a vitamin precursor to NAD+ reduces muscle fiber degeneration and results in significantly faster escape responses in dystrophic embryos. Overexpression of paxillin, a cell adhesion protein downstream of NAD+ in this novel cell adhesion pathway, reduces muscle degeneration in zebrafish with intact integrin receptors but does not improve motility. Activation of this pathway significantly increases organization of laminin, a major component of the extracellular matrix basement membrane. Our results indicate that the primary protective effects of NAD+ result from changes to the basement membrane, as a wild-type basement membrane is sufficient to increase resilience of dystrophic muscle fibers to damage. The surprising result that NAD+ supplementation ameliorates dystrophy in dystrophin-glycoprotein complex– or integrin alpha7–deficient zebrafish suggests the existence of an additional laminin receptor complex that anchors muscle fibers to the basement membrane. We find that integrin alpha6 participates in this pathway, but either integrin alpha7 or the dystrophin-glycoprotein complex is required in conjunction with integrin alpha6 to reduce muscle degeneration. Taken together, these results define a novel cell adhesion pathway that may have future therapeutic relevance for a broad spectrum of muscular dystrophies. PMID:23109907

Exposure to welding fumes and lower airway infection with Streptococcus pneumoniae.

PubMed

Suri, Reetika; Periselneris, Jimstan; Lanone, Sophie; Zeidler-Erdely, Patti C; Melton, Geoffrey; Palmer, Keith T; Andujar, Pascal; Antonini, James M; Cohignac, Vanessa; Erdely, Aaron; Jose, Ricardo J; Mudway, Ian; Brown, Jeremy; Grigg, Jonathan

2016-02-01

Welders are at increased risk of pneumococcal pneumonia. The mechanism for this association is not known. The capacity of pneumococci to adhere to and infect lower airway cells is mediated by host-expressed platelet-activating factor receptor (PAFR). We sought to assess the effect of mild steel welding fumes (MS-WF) on PAFR-dependent pneumococcal adhesion and infection to human airway cells in vitro and on pneumococcal airway infection in a mouse model. The oxidative potential of MS-WF was assessed by their capacity to reduce antioxidants in vitro. Pneumococcal adhesion and infection of A549, BEAS-2B, and primary human bronchial airway cells were assessed by means of quantitative bacterial culture and expressed as colony-forming units (CFU). After intranasal instillation of MS-WF, mice were infected with Streptococcus pneumoniae, and bronchoalveolar lavage fluid (BALF) and lung CFU values were determined. PAFR protein levels were assessed by using immunofluorescence and immunohistochemistry, and PAFR mRNA expression was assessed by using quantitative PCR. PAFR was blocked by CV-3988, and oxidative stress was attenuated by N-acetylcysteine. MS-WF exhibited high oxidative potential. In A549 and BEAS-2B cells MS-WF increased pneumococcal adhesion and infection and PAFR protein expression. Both CV-3988 and N-acetylcysteine reduced MS-WF-stimulated pneumococcal adhesion and infection of airway cells. MS-WF increased mouse lung PAFR mRNA expression and increased BALF and lung pneumococcal CFU values. In MS-WF-exposed mice CV-3988 reduced BALF CFU values. Hypersusceptibility of welders to pneumococcal pneumonia is in part mediated by the capacity of welding fumes to increase PAFR-dependent pneumococcal adhesion and infection of lower airway cells. Copyright © 2015 American Academy of Allergy, Asthma & Immunology. All rights reserved.

Exposure to welding fumes and lower airway infection with Streptococcus pneumoniae

PubMed Central

Suri, Reetika; Periselneris, Jimstan; Lanone, Sophie; Zeidler-Erdely, Patti C.; Melton, Geoffrey; Palmer, Keith T.; Andujar, Pascal; Antonini, James M.; Cohignac, Vanessa; Erdely, Aaron; Jose, Ricardo J.; Mudway, Ian; Brown, Jeremy; Grigg, Jonathan

2015-01-01

Background Welders are at increased risk of pneumococcal pneumonia. The mechanism for this association is not known. The capacity of pneumococci to adhere to and infect lower airway cells is mediated by host-expressed platelet-activating factor receptor (PAFR). Objective We sought to assess the effect of mild steel welding fumes (MS-WF) on PAFR-dependent pneumococcal adhesion and infection to human airway cells in vitro and on pneumococcal airway infection in a mouse model. Methods The oxidative potential of MS-WF was assessed by their capacity to reduce antioxidants in vitro. Pneumococcal adhesion and infection of A549, BEAS-2B, and primary human bronchial airway cells were assessed by means of quantitative bacterial culture and expressed as colony-forming units (CFU). After intranasal instillation of MS-WF, mice were infected with Streptococcus pneumoniae, and bronchoalveolar lavage fluid (BALF) and lung CFU values were determined. PAFR protein levels were assessed by using immunofluorescence and immunohistochemistry, and PAFR mRNA expression was assessed by using quantitative PCR. PAFR was blocked by CV-3988, and oxidative stress was attenuated by N-acetylcysteine. Results: MS-WF exhibited high oxidative potential. In A549 and BEAS-2B cells MS-WF increased pneumococcal adhesion and infection and PAFR protein expression. Both CV-3988 and N-acetylcysteine reduced MS-WF–stimulated pneumococcal adhesion and infection of airway cells. MS-WF increased mouse lung PAFR mRNA expression and increased BALF and lung pneumococcal CFU values. In MS-WF–exposed mice CV-3988 reduced BALF CFU values. Conclusions Hypersusceptibility of welders to pneumococcal pneumonia is in part mediated by the capacity of welding fumes to increase PAFR-dependent pneumococcal adhesion and infection of lower airway cells. PMID:26277596

LGR5 receptor promotes cell-cell adhesion in stem cells and colon cancer cells via the IQGAP1-Rac1 pathway.

PubMed

Carmon, Kendra S; Gong, Xing; Yi, Jing; Wu, Ling; Thomas, Anthony; Moore, Catherine M; Masuho, Ikuo; Timson, David J; Martemyanov, Kirill A; Liu, Qingyun J

2017-09-08

Leucine-rich repeat-containing G protein-coupled receptor 5 (LGR5) is a bona fide marker of adult stem cells in several epithelial tissues, most notably in the intestinal crypts, and is highly up-regulated in many colorectal, hepatocellular, and ovarian cancers. LGR5 activation by R-spondin (RSPO) ligands potentiates Wnt/β-catenin signaling in vitro ; however, deletion of LGR5 in stem cells has little or no effect on Wnt/β-catenin signaling or cell proliferation in vivo Remarkably, modulation of LGR5 expression has a major impact on the actin cytoskeletal structure and cell adhesion in the absence of RSPO stimulation, but the molecular mechanism is unclear. Here, we show that LGR5 interacts with IQ motif-containing GTPase-activating protein 1 (IQGAP1), an effector of Rac1/CDC42 GTPases, in the regulation of actin cytoskeleton dynamics and cell-cell adhesion. Specifically, LGR5 decreased levels of IQGAP1 phosphorylation at Ser-1441/1443, leading to increased binding of Rac1 to IQGAP1 and thus higher levels of cortical F-actin and enhanced cell-cell adhesion. LGR5 ablation in colon cancer cells and crypt stem cells resulted in loss of cortical F-actin, reduced cell-cell adhesion, and disrupted localization of adhesion-associated proteins. No evidence of LGR5 coupling to any of the four major subtypes of heterotrimeric G proteins was found. These findings suggest that LGR5 primarily functions via the IQGAP1-Rac1 pathway to strengthen cell-cell adhesion in normal adult crypt stem cells and colon cancer cells. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Effects of Poloxamer 188 on red blood cell membrane properties in sickle cell anaemia.

PubMed

Sandor, Barbara; Marin, Mickaël; Lapoumeroulie, Claudine; Rabaï, Miklos; Lefevre, Sophie D; Lemonne, Nathalie; El Nemer, Wassim; Mozar, Anaïs; Français, Olivier; Le Pioufle, Bruno; Connes, Philippe; Le Van Kim, Caroline

2016-04-01

Vaso-occlusive crisis (VOC) is the main acute complication in sickle cell anaemia (SS) and several clinical trials are investigating different drugs to improve the clinical severity of SS patients. A phase III study is currently exploring the profit of Velopoloxamer in SS during VOCs. We analysed, in-vitro, the effect of poloxamer (P188) on red blood cell (RBC) properties by investigating haemorheology, mechanical and adhesion functions using ektacytometry, microfluidics and dynamic adhesion approaches, respectively. We show that poloxamer significantly reduces blood viscosity, RBC aggregation and adhesion to endothelial cells, supporting the beneficial use of this molecule in SS therapy. © 2016 John Wiley & Sons Ltd.

Desmoglein 3 regulates membrane trafficking of cadherins, an implication in cell-cell adhesion

PubMed Central

Moftah, Hanan; Dias, Kasuni; Apu, Ehsanul Hoque; Liu, Li; Uttagomol, Jutamas; Bergmeier, Lesley; Kermorgant, Stephanie; Wan, Hong

2017-01-01

ABSTRACT E-cadherin mediated cell-cell adhesion plays a critical role in epithelial cell polarization and morphogenesis. Our recent studies suggest that the desmosomal cadherin, desmoglein 3 (Dsg3) cross talks with E-cadherin and regulates its adhesive function in differentiating keratinocytes. However, the underlying mechanism remains not fully elucidated. Since E-cadherin trafficking has been recognized to be a central determinant in cell-cell adhesion and homeostasis we hypothesize that Dsg3 may play a role in regulating E-cadherin trafficking and hence the cell-cell adhesion. Here we investigated this hypothesis in cells with loss of Dsg3 function through RNAi mediated Dsg3 knockdown or the stable expression of the truncated mutant Dsg3ΔC. Our results showed that loss of Dsg3 resulted in compromised cell-cell adhesion and reduction of adherens junction and desmosome protein expression as well as the cortical F-actin formation. As a consequence, cells failed to polarize but instead displayed aberrant cell flattening. Furthermore, retardation of E-cadherin internalization and recycling was consistently observed in these cells during the process of calcium induced junction assembling. In contrast, enhanced cadherin endocytosis was detected in cells with overexpression of Dsg3 compared to control cells. Importantly, this altered cadherin trafficking was found to be coincided with the reduced expression and activity of Rab proteins, including Rab5, Rab7 and Rab11 which are known to be involved in E-cadherin trafficking. Taken together, our findings suggest that Dsg3 functions as a key in cell-cell adhesion through at least a mechanism of regulating E-cadherin membrane trafficking. PMID:27254775

Glycan-functionalized diamond nanoparticles as potent E. coli anti-adhesives.

PubMed

Barras, Alexandre; Martin, Fernando Ariel; Bande, Omprakash; Baumann, Jean-Sébastien; Ghigo, Jean-Marc; Boukherroub, Rabah; Beloin, Christophe; Siriwardena, Aloysius; Szunerits, Sabine

2013-03-21

Bacterial attachment and subsequent biofilm formation on biotic surfaces or medical devices is an increasing source of infections in clinical settings. A large proportion of these biofilm-related infections are caused by Escherichia coli, a major nosocomial pathogen, in which the major adhesion factor is the FimH adhesin located at the tip of type 1 fimbriae. Inhibition of FimH-mediated adhesion has been identified as an efficient antibiotic-alternative strategy to potentially reduce E. coli-related infections. In this article we demonstrate that nanodiamond particles, covently modified with mannose moieties by a "click" chemistry approach, are able to efficiently inhibit E. coli type 1 fimbriae-mediated adhesion to eukaryotic cells with relative inhibitory potency (RIP) of as high as 9259 (bladder cell adhesion assay), which is unprecedented when compared with RIP values previously reported for alternate multivalent mannose-functionalized nanostructures designed to inhibit E. coli adhesion. Also remarkable is that these novel mannose-modified NDs reduce E. coli biofilm formation, a property previously not observed for multivalent glyco-nanoparticles and rarely demonstrated for other multivalent or monovalent mannose glycans. This work sets the stage for the further evaluation of these novel NDs as an anti-adhesive therapeutic strategy against E. coli-derived infections.

Cell and protein adhesion studies in glaucoma drainage device development

PubMed Central

The, A

1999-01-01

AIM—To examine in vitro whether phosphorylcholine coating of poly(methylmethacrylate) can reduce the adhesion of fibrinogen, fibrin, human scleral fibroblast and macrophage compared with current biomaterials used in the construction of glaucoma drainage devices.
METHODS—Sample discs (n=6) of poly(methylmethacrylate), silicone, polypropylene, PTFE, and phosphorylcholine coated poly(methylmethacrylate) were seeded with fibrinogen, fibrin, fibroblast, and macrophages and incubated for variable lengths of time. The quantification was performed using radioactivity, spectrophotometry, ATP dependent luminometry, and immunohistochemistry respectively.
RESULTS—Fibrinogen and fibrin adhesion to phosphorylcholine coated poly(methylmethacrylate) were significantly lower than PMMA (p=0.004). Phosphorylcholine coating of poly(methylmethacrylate) also significantly reduced the adhesion of human scleral fibroblast (p=0.002) and macrophage (p=0.01) compared with PMMA. All the other biomaterials showed either similar or insignificantly different levels of adhesion to all the proteins and cells tested compared with PMMA.
CONCLUSION—Phosphorylcholine coating is a new material technology that offers considerable promise in the field of glaucoma drainage device development.

 PMID:10502580

Hypoxia-inducible factor regulates alphavbeta3 integrin cell surface expression.

PubMed

Cowden Dahl, Karen D; Robertson, Sarah E; Weaver, Valerie M; Simon, M Celeste

2005-04-01

Hypoxia-inducible factor (HIF)-deficient placentas exhibit a number of defects, including changes in cell fate adoption, lack of fetal angiogenesis, hypocellularity, and poor invasion into maternal tissue. HIF is a heterodimeric transcription factor consisting of alpha and beta aryl hydrocarbon receptor nuclear translocator or ARNT) subunits. We used undifferentiated trophoblast stem (TS) cells to characterize HIF-dependent adhesion, migration, and invasion. Arnt(-/-) and Hifalpha(-/-) TS cells exhibit reduced adhesion and migration toward vitronectin compared with wild-type cells. Furthermore, this defect is associated with decreased cell surface expression of integrin alphavbeta3 and significantly decreased expression of this integrin in focal adhesions. Because of the importance of adhesion and migration in tumor progression (in addition to placental development), we examined the affect of culturing B16F0 melanoma cells in 1.5% oxygen (O(2)). Culturing B16F0 melanoma cells at 1.5% O(2) resulted in increased alphavbeta3 integrin surface expression and increased adhesion to and migration toward vitronectin. Together, these data suggest that HIF and O(2) tension influence placental invasion and tumor migration by increasing cell surface expression of alphavbeta3 integrin.

Hypoxia-inducible Factor Regulates αvβ3 Integrin Cell Surface Expression

PubMed Central

Cowden Dahl, Karen D.; Robertson, Sarah E.; Weaver, Valerie M.; Simon, M. Celeste

2005-01-01

Hypoxia-inducible factor (HIF)-deficient placentas exhibit a number of defects, including changes in cell fate adoption, lack of fetal angiogenesis, hypocellularity, and poor invasion into maternal tissue. HIF is a heterodimeric transcription factor consisting of α and β aryl hydrocarbon receptor nuclear translocator or ARNT) subunits. We used undifferentiated trophoblast stem (TS) cells to characterize HIF-dependent adhesion, migration, and invasion. Arnt-/- and Hifα-/- TS cells exhibit reduced adhesion and migration toward vitronectin compared with wild-type cells. Furthermore, this defect is associated with decreased cell surface expression of integrin αvβ3 and significantly decreased expression of this integrin in focal adhesions. Because of the importance of adhesion and migration in tumor progression (in addition to placental development), we examined the affect of culturing B16F0 melanoma cells in 1.5% oxygen (O2). Culturing B16F0 melanoma cells at 1.5% O2 resulted in increased αvβ3 integrin surface expression and increased adhesion to and migration toward vitronectin. Together, these data suggest that HIF and O2 tension influence placental invasion and tumor migration by increasing cell surface expression of αvβ3 integrin. PMID:15689487

Magnolol reduced TNF-α-induced vascular cell adhesion molecule-1 expression in endothelial cells via JNK/p38 and NF-κB signaling pathways.

PubMed

Liang, Chan-Jung; Lee, Chiang-Wen; Sung, Hsin-Ching; Chen, Yung-Hsiang; Wang, Shu-Huei; Wu, Pei-Jhen; Chiang, Yao-Chang; Tsai, Jaw-Shiun; Wu, Chau-Chung; Li, Chi-Yuan; Chen, Yuh-Lien

2014-01-01

Expression of cell adhesion molecules by the endothelium and the attachment of leukocytes to these cells play major roles in inflammation and cardiovascular disorders. Magnolol, a major active component of Magnolia officinalis, has antioxidative and anti-inflammatory properties. In the present study, the effects of magnolol on the expression of vascular cell adhesion molecule-1 (VCAM-1) in human aortic endothelial cells (HAECs) and the related mechanisms were investigated. TNF-α induced VCAM-1 protein expression and mRNA stability were significantly decreased in HAECs pre-treated with magnolol. Magnolol significantly reduced the phosphorylation of ERK, JNK, and p38 in TNF-α-treated HAECs. The decrease in VCAM-1 expression in response to TNF-α treatment was affected by JNK and p38 inhibitors, not by an ERK inhibitor. Magnolol also attenuates NF-κB activation and the translocation of HuR (an RNA binding protein) in TNF-α-stimulated HAECs. The VCAM-1 expression was weaker in the aortas of TNF-α-treated apo-E deficient mice with magnolol treatment. These data demonstrate that magnolol inhibits TNF-α-induced JNK/p38 phosphorylation, HuR translocation, NF-κB activation, and thereby suppresses VCAM-1 expression resulting in reduced leukocyte adhesion. Taken together, these results suggest that magnolol has an anti-inflammatory property and may play an important role in the prevention of atherosclerosis and inflammatory responses.

Growth and adhesion to HT-29 cells inhibition of Gram-negatives by Bifidobacterium longum BB536 e Lactobacillus rhamnosus HN001 alone and in combination.

PubMed

Inturri, R; Stivala, A; Furneri, P M; Blandino, G

2016-12-01

The aim of this study was to test the inhibitory effect of supernatants of broth cultures of Bifidobacterium longum BB536 and Lactobacillus rhamnosus HN001, both individually and in combination, against Gram-negative strains (uropathogens, enteropathogens and a reference strain). Moreover, in vitro protection of B. longum BB536 and L. rhamnosus HN001, both individually and in combination, against pathogen adhesion to HT-29 cell line, was investigated. The inhibitory activity was performed by the agar diffusion test and in vitro antagonistic activity against pathogen adhesion to human epithelial intestinal HT-29 cells was performed using standardized culture techniques. The study showed that B. longum BB536 and L. rhamnosus HN001, individually and in combination have inhibitory activity against the majority of the Gram negative strains tested. Furthermore, the results showed that both probiotic strains have a good capacity to inhibit pathogenic adhesion to HT-29 cells. Moreover, the ability of B. longum BB536 and L. rhamnosus HN001 to inhibit pathogenic adhesion increased when they were used in combination. The combination of B. longum BB536 and L. rhamnosus HN001 showed inhibitory activity against Gram-negatives and an improved ability to reduce their adhesion properties and to compete with them. The simultaneous presence of the two-probiotic strains could promote competitive mechanisms able to reduce the adhesion properties of pathogen strains and have an important ecological role within the highly competitive environment of the human gut.

Effectiveness and biological compatibility of different generations of dentin adhesives.

PubMed

da Silva, João M F; Rodrigues, José R; Camargo, Carlos H R; Fernandes, Virgilio Vilas Boas; Hiller, Karl-Anton; Schweikl, Helmut; Schmalz, Gottfried

2014-01-01

Besides possessing good mechanical properties, dental materials should present a good biological behavior and should not injure the involved tissues. Bond strength and biocompatibility are both highly significant properties of dentin adhesives. For that matter, these properties of four generations of adhesive systems (Multi-Purpose/Single Bond/SE Plus/Easy Bond) were evaluated. Eighty bovine teeth had their dentin exposed (500- and 200-μm thickness). Adhesive was applied on the dentin layer of each specimen. Following that, the microshearing test was performed for all samples. A dentin barrier test was used for the cytotoxicity evaluation. Cell cultures (SV3NeoB) were collected from testing materials by means of 200- or 500-μm-thick dentin slices and placed in a cell culture perfusion chamber. Cell viability was measured 24 h post-exposition by means of a photometrical test (MTT test). The best bonding performance was shown by the single-step adhesive Easy Bond (21 MPa, 200 μm; 27 MPa, 500 μm) followed by Single Bond (15.6 MPa, 200 μm; 23.4 MPa, 500 μm), SE Plus (18.2 MPa, 200 μm; 20 MPa, 500 μm), and Multi-Purpose (15.2 MPa, 200 μm; 17.9 MPa, 500 μm). Regarding the cytotoxicity, Multi-Purpose slightly reduced the cell viability to 92% (200 μm)/93% (500 μm). Single Bond was reasonably cytotoxic, reducing cell viability to 71% (200 μm)/64% (500 μm). The self-etching adhesive Scotchbond SE decreased cell viability to 85% (200 μm)/71% (500 μm). Conversely, Easy Bond did not reduce cell viability in this test, regardless of the dentin thickness. Results showed that the one-step system had the best bond strength performance and was the least toxic to pulp cells. In multiple-step systems, a correct bonding technique must be done, and a pulp capping strategy is necessary for achieving good performance in both properties. The study showed a promising system (one-step self-etching), referring to it as a good alternative for specific cases, mainly due to its technical simplicity and good biological responses.

The zebrafish galectins Drgal1-L2 and Drgal3-L1 bind in vitro to the infectious hematopoietic necrosis virus (IHNV) glycoprotein and reduce viral adhesion to fish epithelial cells*

PubMed Central

Feng, Chiguang; González-Montalbán, Núria; Ravindran, Chinnarajan; Jackson, Shawn; de las Heras-Sánchez, Ana; Giomarelli, Barbara; Ahmed, Hafiz; Haslam, Stuart M.; Wu, Gang; Dell, Anne; Ammayappan, Arun; Vakharia, Vikram N.; Vasta, Gerardo R.

2015-01-01

The infectious hematopoietic necrosis virus (IHNV; Rhabdoviridae, Novirhabdovirus) infects teleost fish, such as salmon and trout, and is responsible for significant losses in the aquaculture industry and in wild fish populations. Although IHNV enters the host through the skin at the base of the fins, the viral adhesion and entry mechanisms are not fully understood. In recent years, evidence has accumulated in support of the key roles played by protein-carbohydrate interactions between host lectins secreted to the extracellular space and virion envelope glycoproteins in modulating viral adhesion and infectivity. In this study, we assessed in vitro the potential role(s) of zebrafish (Danio rerio) proto type galectin-1 (Drgal1-L2) and a chimera galectin-3 (Drgal3-L1) in IHNV adhesion to epithelial cells. Our results suggest that the extracellular Drgal1-L2 and Drgal3-L1 interact directly and in a carbohydrate-dependent manner with the IHNV glycosylated envelope and glycans on the epithelial cell surface, significantly reducing viral adhesion. PMID:26429411

Gastrin-releasing peptide induces monocyte adhesion to vascular endothelium by upregulating endothelial adhesion molecules

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Mi-Kyoung; Park, Hyun-Joo; Department of Dental Pharmacology, BK21 PLUS Project, School of Dentistry, Pusan National University, Yangsan 626-870

Gastrin-releasing peptide (GRP) is a neuropeptide that plays roles in various pathophysiological conditions including inflammatory diseases in peripheral tissues; however, little is known about whether GRP can directly regulate endothelial inflammatory processes. In this study, we showed that GRP promotes the adhesion of leukocytes to human umbilical vein endothelial cells (HUVECs) and the aortic endothelium. GRP increased the expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) by activating nuclear factor-κB (NF-κB) in endothelial cells. In addition, GRP activated extracellular signal-regulated kinase 1/2 (ERK1/2), p38MAPK, and AKT, and the inhibition of these signaling pathways significantly reduced GRP-inducedmore » monocyte adhesion to the endothelium. Overall, our results suggested that GRP may cause endothelial dysfunction, which could be of particular relevance in the development of vascular inflammatory disorders. - Highlights: • GRP induces adhesion of monocytes to vascular endothelium. • GRP increases the expression of endothelial adhesion molecules through the activation of NF-κB. • ERK1/2, p38MAPK, and Akt pathways are involved in the GRP-induced leukocyte adhesiveness to endothelium.« less

Mesalamine modulates intercellular adhesion through inhibition of p-21 activated kinase-1

PubMed Central

Khare, Vineeta; Lyakhovich, Alex; Dammann, Kyle; Lang, Michaela; Borgmann, Melanie; Tichy, Boris; Pospisilova, Sarka; Luciani, Gloria; Campregher, Christoph; Evstatiev, Rayko; Pflueger, Maren; Hundsberger, Harald; Gasche, Christoph

2013-01-01

Mesalamine (5-ASA) is widely used for the treatment of ulcerative colitis, a remitting condition characterized by chronic inflammation of the colon. Knowledge about the molecular and cellular targets of 5-ASA is limited and a clear understanding of its activity in intestinal homeostasis and interference with neoplastic progression is lacking. We sought to identify molecular pathways interfered by 5-ASA, using CRC cell lines with different genetic background. Microarray was performed for gene expression profile of 5-ASA-treated and untreated cells (HCT116 and HT29). Filtering and analysis of data identified three oncogenic pathways interfered by 5-ASA: MAPK/ERK pathway, cell adhesion and β-catenin/Wnt signaling. PAK1 emerged as a consensus target of 5-ASA, orchestrating these pathways. We further investigated the effect of 5-ASA on cell adhesion. 5-ASA increased cell adhesion which was measured by cell adhesion assay and transcellular-resistance measurement. Moreover, 5-ASA treatment restored membranous expression of adhesion molecules E-cadherin and β-catenin. Role of PAK1 as a mediator of mesalamine activity was validated in vitro and in vivo. Inhibition of PAK1 by RNA interference also increased cell adhesion. PAK1 expression was elevated in APCmin polyps and 5-ASA treatment reduced its expression. Our data demonstrates novel pharmacological mechanism of mesalamine in modulation of cell adhesion and role of PAK1 in APCmin polyposis. We propose that inhibition of PAK1 expression by 5-ASA can impede with neoplastic progression in colorectal carcinogenesis. The mechanism of PAK1 inhibition and induction of membranous translocation of adhesion proteins by 5-ASA might be independent of its known anti-inflammatory action. PMID:23146664

Mesalamine modulates intercellular adhesion through inhibition of p-21 activated kinase-1.

PubMed

Khare, Vineeta; Lyakhovich, Alex; Dammann, Kyle; Lang, Michaela; Borgmann, Melanie; Tichy, Boris; Pospisilova, Sarka; Luciani, Gloria; Campregher, Christoph; Evstatiev, Rayko; Pflueger, Maren; Hundsberger, Harald; Gasche, Christoph

2013-01-15

Mesalamine (5-ASA) is widely used for the treatment of ulcerative colitis, a remitting condition characterized by chronic inflammation of the colon. Knowledge about the molecular and cellular targets of 5-ASA is limited and a clear understanding of its activity in intestinal homeostasis and interference with neoplastic progression is lacking. We sought to identify molecular pathways interfered by 5-ASA, using CRC cell lines with different genetic background. Microarray was performed for gene expression profile of 5-ASA-treated and untreated cells (HCT116 and HT29). Filtering and analysis of data identified three oncogenic pathways interfered by 5-ASA: MAPK/ERK pathway, cell adhesion and β-catenin/Wnt signaling. PAK1 emerged as a consensus target of 5-ASA, orchestrating these pathways. We further investigated the effect of 5-ASA on cell adhesion. 5-ASA increased cell adhesion which was measured by cell adhesion assay and transcellular-resistance measurement. Moreover, 5-ASA treatment restored membranous expression of adhesion molecules E-cadherin and β-catenin. Role of PAK1 as a mediator of mesalamine activity was validated in vitro and in vivo. Inhibition of PAK1 by RNA interference also increased cell adhesion. PAK1 expression was elevated in APC(min) polyps and 5-ASA treatment reduced its expression. Our data demonstrates novel pharmacological mechanism of mesalamine in modulation of cell adhesion and role of PAK1 in APC(min) polyposis. We propose that inhibition of PAK1 expression by 5-ASA can impede with neoplastic progression in colorectal carcinogenesis. The mechanism of PAK1 inhibition and induction of membranous translocation of adhesion proteins by 5-ASA might be independent of its known anti-inflammatory action. Copyright © 2012 Elsevier Inc. All rights reserved.

Comparison of candidate materials for a synthetic osteo-odonto keratoprosthesis device.

PubMed

Tan, Xiao Wei; Perera, A Promoda P; Tan, Anna; Tan, Donald; Khor, K A; Beuerman, Roger W; Mehta, Jodhbir S

2011-01-05

Osteo-odonto keratoprosthesis is one of the most successful forms of keratoprosthesis surgery for end-stage corneal and ocular surface disease. There is a lack of detailed comparison studies on the biocompatibilities of different materials used in keratoprosthesis. The aim of this investigation was to compare synthetic bioinert materials used for keratoprosthesis surgery with hydroxyapatite (HA) as a reference. Test materials were sintered titanium oxide (TiO(2)), aluminum oxide (Al(2)O(3)), and yttria-stabilized zirconia (YSZ) with density >95%. Bacterial adhesion on the substrates was evaluated using scanning electron microscopy and the spread plate method. Surface properties of the implant discs were scanned using optical microscopy. Human keratocyte attachment and proliferation rates were assessed by cell counting and MTT assay at different time points. Morphologic analysis and immunoblotting were used to evaluate focal adhesion formation, whereas cell adhesion force was measured with a multimode atomic force microscope. The authors found that bacterial adhesion on the TiO(2), Al(2)O(3), and YSZ surfaces were lower than that on HA substrates. TiO(2) significantly promoted keratocyte proliferation and viability compared with HA, Al(2)O(3,) and YSZ. Immunofluorescent imaging analyses, immunoblotting, and atomic force microscope measurement revealed that TiO(2) surfaces enhanced cell spreading and cell adhesion compared with HA and Al(2)O(3). TiO(2) is the most suitable replacement candidate for use as skirt material because it enhanced cell functions and reduced bacterial adhesion. This would, in turn, enhance tissue integration and reduce device failure rates during keratoprosthesis surgery.

Cytotoxicity of Etch-and-Rinse, Self-Etch, and Universal Dental Adhesive Systems in Fibroblast Cell Line 3T3

PubMed Central

Bernardo, Cintia Fernanda de Freitas; de Souza, Francielly Fernanda de Freitas A.; Michél, Milton Domingos; Ribeiro, Camila Nunes de Morais; Germano, Sandro; Maluf, Daniela Florencio

2017-01-01

The aim of this study was to evaluate in fibroblast cultures the direct cytotoxic effects of etch-and-rinse, self-etch, and universal adhesive systems. The sterile glass cover slips (n = 3) were then immersed in culture medium to obtain the eluates for the experimental groups: (1) Adper™ Single Bond 2; (2) Ambar; (3) Adper™ Scotchbond™ Multi-Purpose; (4) Scotchbond™ Universal; (5) Ambar Universal; and (6) OptiBond All-In-One. As a negative control, sterile glass cover slips were immersed in culture medium only. After 24 h, the eluate obtained was applied on fibroblast culture. Cell viability and cell morphology were evaluated by MTT assay and SEM, respectively. Data were analyzed by Kruskal–Wallis and Mann–Whitney tests (α = 0.05). All adhesive systems except universal reduced cell viability in 3T3 cells to between 26.04% and 56.57%, and Scotchbond Universal and Ambar Universal reduced cell viability to 2.13% and 3.57%, respectively, when compared to the negative control. Cytoplasmic membrane shrinkage and cell-free areas with residual membrane fragments from dead cells were observed. In conclusion, improvements in universal adhesive system formulations and their mechanisms of action are not accompanied by increased toxicity compared with those in other systems, warranting commitment to the use of these dentin-pulp complexes. PMID:29109829

The effects of caffeic, coumaric and ferulic acids on proliferation, superoxide production, adhesion and migration of human tumor cells in vitro.

PubMed

Nasr Bouzaiene, Nouha; Kilani Jaziri, Soumaya; Kovacic, Hervé; Chekir-Ghedira, Leila; Ghedira, Kamel; Luis, José

2015-11-05

Reactive oxygen species are well-known mediators of various biological responses. In this study, we examined the effect of three phenolic acids, caffeic, coumaric and ferulic acids, on superoxide anion production, adhesion and migration of human lung (A549) and colon adenocarcinoma (HT29-D4) cancer cell lines. Proliferation of both tumor cells was inhibited by phenolic acids. Caffeic, coumaric and ferulic acids also significantly inhibited superoxide production in A549 and HT29-D4 cells. Superoxide anion production decreased by 92% and 77% at the highest tested concentration (200 µM) of caffeic acid in A549 and HT29-D4 cell lines respectively. Furthermore, A549 and HT29-D4 cell adhesion was reduced by 77.9% and 79.8% respectively at the higher tested concentration of ferulic acid (200 µM). Migration assay performed towards A549 cell line, revealed that tested compounds reduced significantly cell migration. At the highest concentration tested (200 µM), the covered surface was 7.7%, 9.5% and 35% for caffeic, coumaric or ferulic acids, respectively. These results demonstrate that caffeic, coumaric and ferulic acids may participate as active ingredients in anticancer agents against lung and colon cancer development, at adhesion and migration steps of tumor progression. Copyright © 2015 Elsevier B.V. All rights reserved.

The candidate tumor suppressor SASH1 interacts with the actin cytoskeleton and stimulates cell-matrix adhesion.

PubMed

Martini, Melanie; Gnann, Alexandra; Scheikl, Daniela; Holzmann, Bernhard; Janssen, Klaus-Peter

2011-11-01

SASH1, a member of the SLY-family of signal adapter proteins, is a candidate tumor suppressor in breast and colon cancer. Reduced expression of SASH1 is correlated with aggressive tumor growth, metastasis formation, and inferior prognosis. However, the biological role of SASH1 remains largely unknown. To unravel the function of SASH1, we have analyzed the intracellular localization of endogenous SASH1, and have generated structural SASH1 mutants. SASH1 localized to the nucleus as well as to the cytoplasm in epithelial cells. In addition, SASH1 was enriched in lamellipodia and membrane ruffles, where it co-distributed with the actin cytoskeleton. Moreover, we demonstrate a novel interaction of SASH1 with the oncoprotein cortactin, a known regulator of actin polymerization in lamellipodia. Enhanced SASH1 expression significantly increased the content of filamentous actin, leading to the formation of cell protrusions and elongated cell shape. This activity was mapped to the central, evolutionarily conserved domain of SASH1. Furthermore, expression of SASH1 inhibited cell migration and lead to increased cell adhesion to fibronectin and laminin, whereas knock-down of endogenous SASH1 resulted in significantly reduced cell-matrix adhesion. Taken together, our findings unravel for the first time a mechanistic role for SASH1 in tumor formation by regulating the adhesive and migratory behaviour of cancer cells. Copyright © 2011 Elsevier Ltd. All rights reserved.

Enhanced adhesion of Streptococcus mutans to hydroxyapatite after exposure to saliva.

PubMed

Spengler, Christian; Thewes, Nicolas; Nolle, Friederike; Faidt, Thomas; Umanskaya, Natalia; Hannig, Matthias; Bischoff, Markus; Jacobs, Karin

2017-07-01

Streptococcus mutans cells form robust biofilms on human teeth and are strongly related to caries incidents. Hence, understanding the adhesion of S. mutans in the human oral cavity is of major interest for preventive dentistry. In this study, we report on atomic force microscopy-based single-cell force spectroscopy measurements of S. mutans cells to hydroxyapatite surfaces. We observe for almost all measurements a significant difference in adhesion strength for S. mutans as well as for Staphylococcus carnosus cells. However, the increase in adhesion strength after saliva exposure is much higher for S. mutans cells compared to S. carnosus cells. Our results demonstrate that S. mutans cells are well adapted to their natural environment, the oral cavity. This ability promotes the biofilm-forming capability of that species and hence the production of caries-provoking acids. In consequence, understanding the fundamentals of this mechanism may pave a way towards more effective caries-reducing techniques. Copyright © 2017 John Wiley & Sons, Ltd.

Inhibitory effect of indigo naturalis on tumor necrosis factor-α-induced vascular cell adhesion molecule-1 expression in human umbilical vein endothelial cells.

PubMed

Chang, Hsin-Ning; Pang, Jong-Hwei Su; Yang, Sien-Hung; Hung, Chi-Feng; Chiang, Chi-Hsin; Lin, Tung-Yi; Lin, Yin-Ku

2010-09-14

The use of indigo naturalis to treat psoriasis has proved effective in our previous clinical studies. The present study was designed to examine the anti-inflammatory effect of indigo naturalis in primary cultured human umbilical vein endothelial cells (HUVECs). Pretreatment of cells with indigo naturalis extract attenuated TNF-α-induced increase in Jurkat T cell adhesion to HUVECs as well as decreased the protein and messenger (m)RNA expression levels of vascular cell adhesion molecule-1 (VCAM-1) on HUVECs. Indigo naturalis extract also inhibited the protein expression of activator protein-1 (AP-1)/c-Jun, a critical transcription factor for the activation of VCAM-1 gene expression. Since the reduction of lymphocyte adhesion to vascular cells by indigo naturalis extract could subsequently reduce the inflammatory reactions caused by lymphocyte infiltration in the epidermal layer and help to improve psoriasis, this study provides a potential mechanism for the anti-inflammatory therapeutic effect of indigo naturalis extract in psoriasis.

Curcumin inhibits activation induced by urban particulate material or titanium dioxide nanoparticles in primary human endothelial cells

PubMed Central

Montiel-Dávalos, Angélica; Silva Sánchez, Guadalupe Jazmin; Huerta-García, Elizabeth; Rueda-Romero, Cristhiam; Soca Chafre, Giovanny; Mitre-Aguilar, Irma B.; Alfaro-Moreno, Ernesto; Pedraza-Chaverri, José

2017-01-01

Curcumin has protective effects against toxic agents and shows preventive properties for various diseases. Particulate material with an aerodynamic diameter of ≤10 μm (PM10) and titanium dioxide nanoparticles (TiO2-NPs) induce endothelial dysfunction and activation. We explored whether curcumin is able to attenuate different events related to endothelial activation. This includes adhesion, expression of adhesion molecules and oxidative stress induced by PM10 and TiO2-NPs. Human umbilical vein endothelial cells (HUVEC) were treated with 1, 10 and 100 μM curcumin for 1 h and then exposed to PM10 at 3 μg/cm2 or TiO2-NPs at 10 μg/cm2. Cell adhesion was evaluated by co-culture with U937 human myelomonocytic cells. Adhesion molecules expression was measured by flow cytometry after 3 or 24 h of exposure. Oxidative stress was determined by 2,7-dichlorodihydrofluorescein (H2DCF) oxidation. PM10 and TiO2-NPs induced the adhesion of U937 cells and the expression of E- and P-selectins, intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and platelet-endothelial cell adhesion molecule-1 (PECAM-1). The expression of E- and P-selectins matched the adhesion of monocytes to HUVEC after 3 h. In HUVEC treated with 1 or 10 μM curcumin, the expression of adhesion molecules and monocytes adhesion was significantly diminished. Curcumin also partially reduced the H2DCF oxidation induced by PM10 and TiO2-NPs. Our results suggest an anti-inflammatory and antioxidant role by curcumin attenuating the activation caused on endothelial cells by exposure to particles. Therefore, curcumin could be useful in the treatment of diseases where an inflammatory process and endothelial activation are involved. PMID:29244817

P38 delta MAPK promotes breast cancer progression and lung metastasis by enhancing cell proliferation and cell detachment.

PubMed

Wada, M; Canals, D; Adada, M; Coant, N; Salama, M F; Helke, K L; Arthur, J S; Shroyer, K R; Kitatani, K; Obeid, L M; Hannun, Y A

2017-11-23

The protein p38 mitogen-activated protein kinase (MAPK) delta isoform (p38δ) is a poorly studied member of the MAPK family. Data analysis from The Cancer Genome Atlas database revealed that p38δ is highly expressed in all types of human breast cancers. Using a human breast cancer tissue array, we confirmed elevation in cancer tissue. The breast cancer mouse model, MMTV-PyMT (PyMT), developed breast tumors with lung metastasis; however, mice deleted in p38δ (PyMT/p38δ -/- ) exhibited delayed primary tumor formation and highly reduced lung metastatic burden. At the cellular level, we demonstrate that targeting of p38δ in breast cancer cells, MCF-7 and MDA-MB-231 resulted in a reduced rate of cell proliferation. In addition, cells lacking p38δ also displayed an increased cell-matrix adhesion and reduced cell detachment. This effect on cell adhesion was molecularly supported by the regulation of the focal adhesion kinase by p38δ in the human breast cell lines. These studies define a previously unappreciated role for p38δ in breast cancer development and evolution by regulating tumor growth and altering metastatic properties. This study proposes MAPK p38δ protein as a key factor in breast cancer. Lack of p38δ resulted in reduced primary tumor size and blocked the metastatic potential to the lungs.

Single Cell Force Spectroscopy for Quantification of Cellular Adhesion on Surfaces

NASA Astrophysics Data System (ADS)

Christenson, Wayne B.

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

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

PubMed

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

2009-10-01

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

Omentin inhibits TNF-{alpha}-induced expression of adhesion molecules in endothelial cells via ERK/NF-{kappa}B pathway

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhong, Xia, E-mail: zhongxia1977@126.com; Li, Xiaonan; Liu, Fuli

2012-08-24

Highlights: Black-Right-Pointing-Pointer Omentin inhibited TNF-{alpha}-induced adhesion of THP-1 cells to HUVECs. Black-Right-Pointing-Pointer Omentin reduces expression of ICAM-1 and VCAM-1 induced by TNF-{alpha} in HUVECs. Black-Right-Pointing-Pointer Omentin inhibits TNF-{alpha}-induced ERK and NF-{kappa}B activation in HUVECs. Black-Right-Pointing-Pointer Omentin supreeses TNF-{alpha}-induced expression of ICAM-1 and VCAM-1 via ERK/NF-{kappa}B pathway. -- Abstract: In the present study, we investigated whether omentin affected the expression of intracellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) in tumor necrosis factor-{alpha} (TNF-{alpha}) induced human umbilical vein endothelial cells (HUVECs). Our data showed that omentin decreased TNF-{alpha}-induced expression of ICAM-1 and VCAM-1 in HUVECs. In addition, omentin inhibitedmore » TNF-{alpha}-induced adhesion of THP-1 cells to HUVECs. Further, we found that omentin inhibited TNF-{alpha}-activated signal pathway of nuclear factor-{kappa}B (NF-{kappa}B) by preventing NF-{kappa}B inhibitory protein (I{kappa}B{alpha}) degradation and NF-{kappa}B/DNA binding activity. Omentin pretreatment significantly inhibited TNF-{alpha}-induced ERK activity and ERK phosphorylation in HUVECs. Pretreatment with PD98059 suppressed TNF-{alpha}-induced NF-{kappa}B activity. Omentin, NF-kB inhibitor (BAY11-7082) and ERK inhibitor (PD98059) reduced the up-regulation of ICAM-1 and VCAM-1 induced by TNF-{alpha}. These results suggest that omentin may inhibit TNF-{alpha}-induced expression of adhesion molecules in endothelial cells via blocking ERK/NF-{kappa}B pathway.« less

Chrysin Attenuates VCAM-1 Expression and Monocyte Adhesion in Lipopolysaccharide-Stimulated Brain Endothelial Cells by Preventing NF-κB Signaling.

PubMed

Lee, Bo Kyung; Lee, Won Jae; Jung, Yi-Sook

2017-07-03

Adhesion of leukocytes to endothelial cells plays an important role in neuroinflammation. Therefore, suppression of the expression of adhesion molecules in brain endothelial cells may inhibit neuroinflammation. Chrysin (5,7-dihydroxyflavone) is a flavonoid component of propolis, blue passion flowers, and fruits. In the present study, we examined the effects of chrysin on lipopolysaccharide (LPS)-induced expression of vascular cell adhesion molecule-1 (VCAM-1) in mouse cerebral vascular endothelial (bEnd.3) cells. In bEnd.3 cells, LPS increased mRNA expression of VCAM-1 in a time-dependent manner, and chrysin significantly decreased LPS-induced mRNA expression of VCAM-1. Chrysin also reduced VCAM-1 protein expression in a concentration-dependent manner. Furthermore, chrysin blocked adhesion of monocytes to bEnd.3 cells exposed to LPS. Nuclear factor-κB (NF-κB), p38 mitogen-activated protein kinase (MAPK), and c-Jun N-terminal kinase, which are all activated by LPS, were significantly inhibited by chrysin. These results indicate that chrysin inhibits the expression of VCAM-1 in brain endothelial cells by inhibiting NF-κB translocation and MAPK signaling, resulting in the attenuation of leukocyte adhesion to endothelial cells. The anti-inflammatory effects of chrysin suggest a possible therapeutic application of this agent to neurodegenerative diseases, such as multiple sclerosis, septic encephalopathy, and allergic encephalomyelitis.

Human dental pulp stem cell adhesion and detachment in polycaprolactone electrospun scaffolds under direct perfusion

PubMed Central

Paim, A.; Braghirolli, D.I.; Cardozo, N.S.M.; Pranke, P.; Tessaro, I.C.

2018-01-01

Cell adhesion in three-dimensional scaffolds plays a key role in tissue development. However, stem cell behavior in electrospun scaffolds under perfusion is not fully understood. Thus, an investigation was made on the effect of flow rate and shear stress, adhesion time, and seeding density under direct perfusion in polycaprolactone electrospun scaffolds on human dental pulp stem cell detachment. Polycaprolactone scaffolds were electrospun using a solvent mixture of chloroform and methanol. The viable cell number was determined at each tested condition. Cell morphology was analyzed by confocal microscopy after various incubation times for static cell adhesion with a high seeding density. Scanning electron microscopy images were obtained before and after perfusion for the highest flow rate tested. The wall pore shear stress was calculated for all tested flow rates (0.005–3 mL/min). An inversely proportional relationship between adhesion time with cell detachment under perfusion was observed. Lower flow rates and lower seeding densities reduced the drag of cells by shear stress. However, there was an operational limit for the lowest flow rate that can be used without compromising cell viability, indicating that a flow rate of 0.05 mL/min might be more suitable for the tested cell culture in electrospun scaffolds under direct perfusion. PMID:29590258

TM9/Phg1 and SadA proteins control surface expression and stability of SibA adhesion molecules in Dictyostelium.

PubMed

Froquet, Romain; le Coadic, Marion; Perrin, Jackie; Cherix, Nathalie; Cornillon, Sophie; Cosson, Pierre

2012-02-01

TM9 proteins form a family of conserved proteins with nine transmembrane domains essential for cellular adhesion in many biological systems, but their exact role in this process remains unknown. In this study, we found that genetic inactivation of the TM9 protein Phg1A dramatically decreases the surface levels of the SibA adhesion molecule in Dictyostelium amoebae. This is due to a decrease in sibA mRNA levels, in SibA protein stability, and in SibA targeting to the cell surface. A similar phenotype was observed in cells devoid of SadA, a protein that does not belong to the TM9 family but also exhibits nine transmembrane domains and is essential for cellular adhesion. A contact site A (csA)-SibA chimeric protein comprising only the transmembrane and cytosolic domains of SibA and the extracellular domain of the Dictyostelium surface protein csA also showed reduced stability and relocalization to endocytic compartments in phg1A knockout cells. These results indicate that TM9 proteins participate in cell adhesion by controlling the levels of adhesion proteins present at the cell surface.

Collisions of deformable cells lead to collective migration

NASA Astrophysics Data System (ADS)

Löber, Jakob; Ziebert, Falko; Aranson, Igor S.

2015-03-01

Collective migration of eukaryotic cells plays a fundamental role in tissue growth, wound healing and immune response. The motion, arising spontaneously or in response to chemical and mechanical stimuli, is also important for understanding life-threatening pathologies, such as cancer and metastasis formation. We present a phase-field model to describe the movement of many self-organized, interacting cells. The model takes into account the main mechanisms of cell motility - acto-myosin dynamics, as well as substrate-mediated and cell-cell adhesion. It predicts that collective cell migration emerges spontaneously as a result of inelastic collisions between neighboring cells: collisions lead to a mutual alignment of the cell velocities and to the formation of coherently-moving multi-cellular clusters. Small cell-to-cell adhesion, in turn, reduces the propensity for large-scale collective migration, while higher adhesion leads to the formation of moving bands. Our study provides valuable insight into biological processes associated with collective cell motility.

Tropomyosin Tm5NM1 Spatially Restricts Src Kinase Activity through Perturbation of Rab11 Vesicle Trafficking

PubMed Central

Bach, Cuc T.; Murray, Rachael Z.; Owen, Dylan; Gaus, Kat

2014-01-01

In order for cells to stop moving, they must synchronously stabilize actin filaments and their associated focal adhesions. How these two structures are coordinated in time and space is not known. We show here that the actin association protein Tm5NM1, which induces stable actin filaments, concurrently suppresses the trafficking of focal-adhesion-regulatory molecules. Using combinations of fluorescent biosensors and fluorescence recovery after photobleaching (FRAP), we demonstrate that Tm5NM1 reduces the level of delivery of Src kinase to focal adhesions, resulting in reduced phosphorylation of adhesion-resident Src substrates. Live imaging of Rab11-positive recycling endosomes that carry Src to focal adhesions reveals disruption of this pathway. We propose that tropomyosin synchronizes adhesion dynamics with the cytoskeleton by regulating actin-dependent trafficking of essential focal-adhesion molecules. PMID:25288639

Persistent Transmissible Gastroenteritis Virus Infection Enhances Enterotoxigenic Escherichia coli K88 Adhesion by Promoting Epithelial-Mesenchymal Transition in Intestinal Epithelial Cells.

PubMed

Xia, Lu; Dai, Lei; Yu, Qinghua; Yang, Qian

2017-11-01

Transmissible gastroenteritis virus (TGEV) is a coronavirus characterized by diarrhea and high morbidity rates, and the mortality rate is 100% in piglets less than 2 weeks old. Pigs infected with TGEV often suffer secondary infection by other pathogens, which aggravates the severity of diarrhea, but the mechanisms remain unknown. Here, we hypothesized that persistent TGEV infection stimulates the epithelial-mesenchymal transition (EMT), and thus enterotoxigenic Escherichia coli (ETEC) can more easily adhere to generating cells. Intestinal epithelial cells are the primary targets of TGEV and ETEC infections. We found that TGEV can persistently infect porcine intestinal columnar epithelial cells (IPEC-J2) and cause EMT, consistent with multiple changes in key cell characteristics. Infected cells display fibroblast-like shapes; exhibit increases in levels of mesenchymal markers with a corresponding loss of epithelial markers; have enhanced expression levels of interleukin-1β (IL-1β), IL-6, IL-8, transforming growth factor β (TGF-β), and tumor necrosis factor alpha (TNF-α) mRNAs; and demonstrate increases in migratory and invasive behaviors. Additional experiments showed that the activation of the phosphatidylinositol 3-kinase (PI3K)/Akt and extracellular signal-regulated kinase (ERK) signaling pathways via TGF-β is critical for the TGEV-mediated EMT process. Cellular uptake is also modified in cells that have undergone EMT. TGEV-infected cells have higher levels of integrin α5 and fibronectin and exhibit enhanced ETEC K88 adhesion. Reversal of EMT reduces ETEC K88 adhesion and inhibits the expression of integrin α5 and fibronectin. Overall, these results suggest that TGEV infection induces EMT in IPEC-J2 cells, increasing the adhesion of ETEC K88 in the intestine and facilitating dual infection. IMPORTANCE Transmissible gastroenteritis virus (TGEV) causes pig diarrhea and is often followed by secondary infection by other pathogens. In this study, we showed that persistent TGEV infection induces an EMT in porcine intestinal columnar epithelial cells (IPEC-J2) and enhances the adhesion of the secondary pathogen ETEC K88. Additional experiments suggest that integrin α5 and fibronectin play an important role in TGEV-enhanced ETEC K88 adhesion. Reversal of EMT reduces the expression of integrin α5 and fibronectin and also reduces ETEC K88 adhesion. We conclude that TGEV infection triggers EMT and facilitates dual infection. Our results provide new insights into secondary infection and suggest that targeted anti-EMT therapy may have implications for the prevention and treatment of secondary infection. Copyright © 2017 American Society for Microbiology.

Biocompatibility Evaluation of Four Dentin Adhesives Used as Indirect Pulp Capping Materials

PubMed Central

Cortés, Olga; Bernabé, Antonia

2017-01-01

Background In many cases, the indirect pulp treatment (IPT) is an acceptable treatment for deciduous teeth with reversible pulp inflammation. Various medicaments have been used for IPT, ranging from calcium hydroxide and glass ionomers to dentin adhesives. Objective This in vitro trial aimed to measure cytotoxicity in a cell culture, comparing the following four adhesives: Xeno® V (XE), Excite® F DSC (EX), Adhese® OneF (AD) and Prime & Bond NT (PB). Materials and methods The adhesives were prepared according to the manufacturer’s instructions. After 24 hours of exposure, the cell viability was evaluated using a photometrical test (MTT test). Data were subjected to analysis of variance (ANOVA). Results Adhesives, the main component of which was 2-hydroxyethyl methacrylate (HEMA), were found to be less cytotoxic, while those that included the monomer urethane dimethacrylate (UDMA were the most cytotoxic) in their composition. The effects on cell viability assay varied between the adhesives assayed with statistically significant differences. Conclusions The results may support the argument that Adhese® OneF is the least cytotoxic of the adhesives assayed, and may be considered as an adhesive agent for indirect pulp treatment. However, Prime and Bond NT showed a reduced biocompatibility under the same conditions. PMID:28827848

Heme oxygenase-1 protects INF-gamma primed endothelial cells from Jurkat T-cell adhesion.

PubMed

Du, D; Chang, S; Chen, B; Zhou, H; Chen, Z K

2007-12-01

The heme oxygenase-1 (HO-1) system is associated with the rate-limiting step of conversion of heme, one of the most critical roles in cytoprotective mechanisms. Our study investigated its potential role in protection of endothelial cells from T cells. The recombinant plasmid pcDNA3-HO-1 was transfected into endothelial cells. Indirect fluorescent staining was used to examine the expression of HO-1 protein. Then endothelial cells primed by INF-gamma were mixed in culture with Jurkat T cells labeled with carboxyfluorescein diacetate succinimidyl ester (CFSE). The number of adhesive Jurkat T cells was determined using FACS to evaluate the adhesion effect. After being cultured with endothelial cells, the cell cycle of Jurkat T cells was detected using FACS. Expression of HO-1 on endothelial cells conferred significant protection against Jurkat T-cell-mediated adhesion. The rate of Jurkat T-cell adhesions was reduced to 19.06%, in contrast with 31.42% in the control group (P<.05). After using ZnPP, an inhibitor of HO-1, the rate of Jurkat T-cell adhesion recovered to 29.08%. The binding activities between endothelial cells and Jurkat T cells was blocked by HO-1 expression. The proliferation of Jurkat T cells was inhibited after culture with endothelial cells, which had been transfected with HO-1, which blocked cell cycle entry of T cells. More than 60% of Jurkat T cells remained in G0/G1 compared with 40% among the control group. HO-1 directly protected endothelial cells primed by INF-gamma from Jurkat T cells and down-regulated the expression of HLA-DR on the surface of endothelial cells. These results indicated that transgenic expression of HO-1 may be useful to prevent lymphocytes from responding to endothelial cells.

Anti-inflammatory effects of methylthiouracil in vitro and in vivo

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ku, Sae-Kwang; Baek, Moon-Chang, E-mail: mcbaek@knu.ac.kr; Bae, Jong-Sup, E-mail: baejs@knu.ac.kr

The screening of bioactive compound libraries can be an effective approach for repositioning FDA-approved drugs or discovering new treatments for human diseases. Here, methylthiouracil (MTU), an antithyroid drug, was examined for its effects on lipopolysaccharide (LPS)-mediated vascular inflammatory responses. The anti-inflammatory activities of MTU were determined by measuring permeability, human neutrophil adhesion and migration, and activation of pro-inflammatory proteins in LPS-activated human umbilical vein endothelial cells and mice. We found that post-treatment with MTU inhibited LPS-induced barrier disruption, expression of cell adhesion molecules (CAMs), and adhesion/transendothelial migration of human neutrophils to human endothelial cells. MTU induced potent inhibition of LPS-inducedmore » endothelial cell protein C receptor (EPCR) shedding. It also suppressed LPS-induced hyperpermeability and neutrophil migration in vivo. Furthermore, MTU suppressed the production of tumor necrosis factor-α (TNF-α) and interleukin (IL)-6, and the activation of nuclear factor-κB (NF-κB) and extracellular regulated kinases (ERK) 1/2 by LPS. Moreover, post-treatment with MTU resulted in reduced LPS-induced lethal endotoxemia. These results suggest that MTU exerts anti-inflammatory effects by inhibiting hyperpermeability, expression of CAMs, and adhesion and migration of leukocytes, thereby endorsing its usefulness as a therapy for vascular inflammatory diseases. - Highlights: • MTU reduced LPS-mediated hyperpermeability in vitro and in vivo. • MTU inhibited LPS-mediated leukocyte adhesion and migration. • MTU inhibited LPS-mediated production of IL-6 and TNF-α. • MTU reduced LPS-mediated mortality and lung injury.« less

Micrometer scale spacings between fibronectin nanodots regulate cell morphology and focal adhesions

NASA Astrophysics Data System (ADS)

Horzum, Utku; Ozdil, Berrin; Pesen-Okvur, Devrim

2014-04-01

Cell adhesion to extracellular matrix is an important process for both health and disease states. Surface protein patterns that are topographically flat, and do not introduce other chemical, topographical or rigidity related functionality and, more importantly, that mimic the organization of the in vivo extracellular matrix are desired. Previous work showed that vinculin and cytoskeletal organization are modulated by size and shape of surface nanopatterns. However, quantitative analysis on cell morphology and focal adhesions as a function of micrometer scale spacings of FN nanopatterns was absent. Here, electron beam lithography was used to pattern fibronectin nanodots with micrometer scale spacings on a K-casein background on indium tin oxide coated glass which, unlike silicon, is transparent and thus suitable for many light microscopy techniques. Exposure times were significantly reduced using the line exposure mode with micrometer scale step sizes. Micrometer scale spacings of 2, 4 and 8 μm between fibronectin nanodots proved to modulate cell adhesion through modification of cell area, focal adhesion number, size and circularity. Overall, cell behavior was shown to shift at the apparent threshold of 4 μm spacing. The findings presented here offer exciting new opportunities for cell biology research.

αE-catenin regulates actin dynamics independently of cadherin-mediated cell–cell adhesion

PubMed Central

Benjamin, Jacqueline M.; Kwiatkowski, Adam V.; Yang, Changsong; Korobova, Farida; Pokutta, Sabine; Svitkina, Tatyana

2010-01-01

αE-catenin binds the cell–cell adhesion complex of E-cadherin and β-catenin (β-cat) and regulates filamentous actin (F-actin) dynamics. In vitro, binding of αE-catenin to the E-cadherin–β-cat complex lowers αE-catenin affinity for F-actin, and αE-catenin alone can bind F-actin and inhibit Arp2/3 complex–mediated actin polymerization. In cells, to test whether αE-catenin regulates actin dynamics independently of the cadherin complex, the cytosolic αE-catenin pool was sequestered to mitochondria without affecting overall levels of αE-catenin or the cadherin–catenin complex. Sequestering cytosolic αE-catenin to mitochondria alters lamellipodia architecture and increases membrane dynamics and cell migration without affecting cell–cell adhesion. In contrast, sequestration of cytosolic αE-catenin to the plasma membrane reduces membrane dynamics. These results demonstrate that the cytosolic pool of αE-catenin regulates actin dynamics independently of cell–cell adhesion. PMID:20404114

Polymer surface functionalities that control human embryoid body cell adhesion revealed by high throughput surface characterization of combinatorial material microarrays

PubMed Central

Yang, Jing; Mei, Ying; Hook, Andrew L.; Taylor, Michael; Urquhart, Andrew J.; Bogatyrev, Said R.; Langer, Robert; Anderson, Daniel G.; Davies, Martyn C.; Alexander, Morgan R.

2010-01-01

High throughput materials discovery using combinatorial polymer microarrays to screen for new biomaterials with new and improved function is established as a powerful strategy. Here we combine this screening approach with high throughput surface characterisation (HT-SC) to identify surface structure-function relationships. We explore how this combination can help to identify surface chemical moieties that control protein adsorption and subsequent cellular response. The adhesion of human embryoid body (hEB) cells to a large number (496) of different acrylate polymers synthesized in a microarray format is screened using a high throughput procedure. To determine the role of the polymer surface properties on hEB cell adhesion, detailed HT-SC of these acrylate polymers is carried out using time of flight secondary ion mass spectrometry (ToF SIMS), x-ray photoelectron spectroscopy (XPS), pico litre drop sessile water contact angle (WCA) measurement and atomic force microscopy (AFM). A structure-function relationship is identified between the ToF SIMS analysis of the surface chemistry after a fibronectin (Fn) pre-conditioning step and the cell adhesion to each spot using the multivariate analysis technique partial least squares (PLS) regression. Secondary ions indicative of the adsorbed Fn correlate with increased cell adhesion whereas glycol and other functionalities from the polymers are identified that reduce cell adhesion. Furthermore, a strong relationship between the ToF SIMS spectra of bare polymers and the cell adhesion to each spot is identified using PLS regression. This identifies a role for both the surface chemistry of the bare polymer and the pre-adsorbed Fn, as-represented in the ToF SIMS spectra, in controlling cellular adhesion. In contrast, no relationship is found between cell adhesion and wettability, surface roughness, elemental or functional surface composition. The correlation between ToF SIMS data of the surfaces and the cell adhesion demonstrates the ability of identifying surface moieties that control protein adsorption and subsequent cell adhesion using ToF SIMS and multivariate analysis. PMID:20832108

Soluble fragments of e-cadherin cell-adhesion molecule increase in urinary-excretion of cancer-patients, potentially indicating its shedding from epithelial tumor-cells.

PubMed

Katayama, M; Hirai, S; Yasumoto, M; Nishikawa, K; Nagata, S; Otsuka, M; Kamihagi, K; Kato, I

1994-11-01

E-cadherin (Ecad) is well known to be a calcium-ion-dependent cell-cell adhesion molecule expressed mostly in epithelial tissues. Previous immunohistochemical studies suggested that this cell adhesion molecule acts as an invasion suppressor and is negligibly detected in cancer metastatic regions. Soluble Ecad fragments derived from the proteolysed membrane-associated form were detected in culture supernatants of two cell lines, COLO 205 and A-431, with normal distribution of cell surface Ecad. Soluble Ecad levels released into culture of COLO 205 exhibiting reduced cell-cell adhesion were apparently elevated above those of A-431 with tight cell-cell adhesion. Furthermore, human circulation and urine continuously contain soluble Ecad which consists mainly of homogeneous 75-85 kDa extracellular domains. Soluble Ecad urinary level per urinary creatinine level was found to be significantly elevated in 53% of patients suffering from various types of cancers including lung, liver, stomach, colon and rectal cancers, as compared with those in the age-matched healthy subjects. These results suggest that dysfunction of cell surface Ecad is responsible for its enhanced proteolytic shedding in tumorigenesis, which may lead to the decrease of cell surface Ecads. Furthermore, excretion of high levels of soluble Ecad fragments potentially indicates the progression of epithelial tumors excessively degrading cell surface Ecad in clinical subjects.

Edaravone attenuates monocyte adhesion to endothelial cells induced by oxidized low-density lipoprotein.

PubMed

Li, Zhijuan; Cheng, Jianxin; Wang, Liping

2015-10-30

Oxidized low-density lipoprotein (oxLDL) plays a vital role in recruitment of monocytes to endothelial cells, which is important during early stages of atherosclerosis development. Edaravone, a potent and novel scavenger of free radicals inhibiting hydroxyl radicals, has been clinically used to reduce the neuronal damage following ischemic stroke. In the present study, Edaravone was revealed to markedly reduce oxLDL-induced monocyte adhesion to human umbilical vein endothelial cells (HUVECs). The inhibitory mechanism of Edaravone was associated with suppression of the chemokine MCP-1 and adhesion molecule VCAM-1 and ICAM-1 expression. In addition, luciferase reporter assay results revealed that administration of Edaravone attenuated the increase in NF-κB transcriptional activity induced by oxLDL. Notably, it's also shown that Edaravone treatment blocked oxLDL induced p65 nuclear translocation in HUVECs. Results indicate that Edaravone negatively regulates endothelial inflammation. Copyright © 2015. Published by Elsevier Inc.

Genetic ablation of zyxin causes Mena/VASP mislocalization, increased motility, and deficits in actin remodeling

PubMed Central

Hoffman, Laura M.; Jensen, Christopher C.; Kloeker, Susanne; Wang, C.-L. Albert; Yoshigi, Masaaki; Beckerle, Mary C.

2006-01-01

Focal adhesions are specialized regions of the cell surface where integrin receptors and associated proteins link the extracellular matrix to the actin cytoskeleton. To define the cellular role of the focal adhesion protein zyxin, we characterized the phenotype of fibroblasts in which the zyxin gene was deleted by homologous recombination. Zyxin-null fibroblasts display enhanced integrin-dependent adhesion and are more migratory than wild-type fibroblasts, displaying reduced dependence on extracellular matrix cues. We identified differences in the profiles of 75- and 80-kD tyrosine-phosphorylated proteins in the zyxin-null cells. Tandem array mass spectrometry identified both modified proteins as isoforms of the actomyosin regulator caldesmon, a protein known to influence contractility, stress fiber formation, and motility. Zyxin-null fibroblasts also show deficits in actin stress fiber remodeling and exhibit changes in the molecular composition of focal adhesions, most notably by severely reduced accumulation of Ena/VASP proteins. We postulate that zyxin cooperates with Ena/VASP proteins and caldesmon to influence integrin-dependent cell motility and actin stress fiber remodeling. PMID:16505170

Mycophenolate mofetil modulates adhesion receptors of the beta1 integrin family on tumor cells: impact on tumor recurrence and malignancy

PubMed Central

Engl, Tobias; Makarević, Jasmina; Relja, Borna; Natsheh, Iyad; Müller, Iris; Beecken, Wolf-Dietrich; Jonas, Dietger; Blaheta, Roman A

2005-01-01

Background Tumor development remains one of the major obstacles following organ transplantation. Immunosuppressive drugs such as cyclosporine and tacrolimus directly contribute to enhanced malignancy, whereas the influence of the novel compound mycophenolate mofetil (MMF) on tumor cell dissemination has not been explored. We therefore investigated the adhesion capacity of colon, pancreas, prostate and kidney carcinoma cell lines to endothelium, as well as their beta1 integrin expression profile before and after MMF treatment. Methods Tumor cell adhesion to endothelial cell monolayers was evaluated in the presence of 0.1 and 1 μM MMF and compared to unstimulated controls. beta1 integrin analysis included alpha1beta1 (CD49a), alpha2beta1 (CD49b), alpha3beta1 (CD49c), alpha4beta1 (CD49d), alpha5beta1 (CD49e), and alpha6beta1 (CD49f) receptors, and was carried out by reverse transcriptase-polymerase chain reaction, confocal microscopy and flow cytometry. Results Adhesion of the colon carcinoma cell line HT-29 was strongly reduced in the presence of 0.1 μM MMF. This effect was accompanied by down-regulation of alpha3beta1 and alpha6beta1 surface expression and of alpha3beta1 and alpha6beta1 coding mRNA. Adhesion of the prostate tumor cell line DU-145 was blocked dose-dependently by MMF. In contrast to MMF's effects on HT-29 cells, MMF dose-dependently up-regulated alpha1beta1, alpha2beta1, alpha3beta1, and alpha5beta1 on DU-145 tumor cell membranes. Conclusion We conclude that MMF possesses distinct anti-tumoral properties, particularly in colon and prostate carcinoma cells. Adhesion blockage of HT-29 cells was due to the loss of alpha3beta1 and alpha6beta1 surface expression, which might contribute to a reduced invasive behaviour of this tumor entity. The enhancement of integrin beta1 subtypes observed in DU-145 cells possibly causes re-differentiation towards a low-invasive phenotype. PMID:15644133

Fumaric Acid Esters Do Not Reduce Inflammatory NF-κB/p65 Nuclear Translocation, ICAM-1 Expression and T-Cell Adhesiveness of Human Brain Microvascular Endothelial Cells.

PubMed

Haarmann, Axel; Nehen, Mathias; Deiß, Annika; Buttmann, Mathias

2015-08-13

Dimethyl fumarate (DMF) is approved for disease-modifying treatment of patients with relapsing-remitting multiple sclerosis. Animal experiments suggested that part of its therapeutic effect is due to a reduction of T-cell infiltration of the central nervous system (CNS) by uncertain mechanisms. Here we evaluated whether DMF and its primary metabolite monomethyl fumarate (MMF) modulate pro-inflammatory intracellular signaling and T-cell adhesiveness of nonimmortalized single donor human brain microvascular endothelial cells at low passages. Neither DMF nor MMF at concentrations of 10 or 50 µM blocked the IL-1β-induced nuclear translocation of NF-κB/p65, whereas the higher concentration of DMF inhibited the nuclear entry of p65 in human umbilical vein endothelium cultured in parallel. DMF and MMF also did not alter the IL-1β-stimulated activation of p38 MAPK in brain endothelium. Furthermore, neither DMF nor MMF reduced the basal or IL-1β-inducible expression of ICAM-1. In accordance, both fumaric acid esters did not reduce the adhesion of activated Jurkat T cells to brain endothelium under basal or inflammatory conditions. Therefore, brain endothelial cells probably do not directly mediate a potential blocking effect of fumaric acid esters on the inflammatory infiltration of the CNS by T cells.

Connexin 32 and its derived homotypic gap junctional intercellular communication inhibit the migration and invasion of transfected HeLa cells via enhancement of intercellular adhesion.

PubMed

Yang, Jie; Liu, Bing; Wang, Qin; Yuan, Dongdong; Hong, Xiaoting; Yang, Yan; Tao, Liang

2011-01-01

The effects of connexin (Cx) and its derived homotypic gap junctional intercellular communication (GJIC) between tumor cells on the invasion of metastatic cancers and the underlying mechanisms remain unclear. In this study, we investigated the influence of Cx32 and the homotypic GJIC mediated by this Cx on the migration, invasion and intercellular adhesion of transfected HeLa cells. The expression of Cx32 significantly increased cell adhesion and inhibited migration and invasion. The inhibition of GJIC by oleamide, a widely used GJIC inhibitor, reduced the enhanced adhesion and partly reversed the decreased migration and invasion that had been induced by Cx32 expression. Blockage of the p38 and extracellular signal-regulated kinase 1 and 2 mitogen-activated protein kinase (ERK1/2 MAPKs) pathways using their specific inhibitors attenuated the effects of Cx32, but not those of GJIC, on cell adhesion, migration and invasion. These results indicate that the homotypic GJIC mediated by Cx32, as well as the Cx itself, inhibit cell migration and invasion, most likely through the elevation of intercellular adhesion. The suppressive effect of Cx32 on the migration and invasion of cancer cells, but not that of its derived homotypic GJIC, partly depends on the activation of the p38 and the ERK1/2 MAPKs pathways.

Nitrogen starvation affects bacterial adhesion to soil

PubMed Central

Borges, Maria Tereza; Nascimento, Antônio Galvão; Rocha, Ulisses Nunes; Tótola, Marcos Rogério

2008-01-01

One of the main factors limiting the bioremediation of subsoil environments based on bioaugmentation is the transport of selected microorganisms to the contaminated zones. The characterization of the physiological responses of the inoculated microorganisms to starvation, especially the evaluation of characteristics that affect the adhesion of the cells to soil particles, is fundamental to anticipate the success or failure of bioaugmentation. The objective of this study was to investigate the effect of nitrogen starvation on cell surface hydrophobicity and cell adhesion to soil particles by bacterial strains previously characterized as able to use benzene, toluene or xilenes as carbon and energy sources. The strains LBBMA 18-T (non-identified), Arthrobacter aurescens LBBMA 98, Arthrobacter oxydans LBBMA 201, and Klebsiella sp. LBBMA 204–1 were used in the experiments. Cultivation of the cells in nitrogen-deficient medium caused a significant reduction of the adhesion to soil particles by all the four strains. Nitrogen starvation also reduced significantly the strength of cell adhesion to the soil particles, except for Klebsiella sp. LBBMA 204–1. Two of the four strains showed significant reduction in cell surface hydrophobicity. It is inferred that the efficiency of bacterial transport through soils might be potentially increased by nitrogen starvation. PMID:24031246

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

PubMed

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

2007-03-01

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

Decoy receptor 3 promotes cell adhesion and enhances endometriosis development.

PubMed

Tsai, Hsiao-Wen; Huang, Ming-Ting; Wang, Peng-Hui; Huang, Ben-Shian; Chen, Yi-Jen; Hsieh, Shie-Liang

2018-02-01

Endometriosis is a multifactorial inflammatory disease with persistent activation of the nuclear factor-κB (NF-κB) signalling pathway. Aberrant adhesion of endometrium is the essential step in the progression of endometriosis, but the molecular mechanism of ectopic growth of endometrium is still unclear. Decoy receptor 3 (DcR3)/TNFRSF6B, a pleiotropic immunomodulator regulated by oestrogen, is able to activate focal adhesion kinase to promote cell adhesion. We found that DcR3 is upregulated in human ectopic endometrial cells via activation of the Akt-NF-κB signalling pathway, and its expression level correlates positively with that of the adhesion molecules intercellular adhesion molecule 1 (ICAM-1) and homing cell adhesion molecule (HCAM; CD44). In a multivariate regression model, DcR3 expression level was the most significant parameter associated with endometriosis severity. Knockdown of DcR3 not only downregulated the expression of ICAM-1 and HCAM, but also reduced cell adhesion and migration. In vivo investigation further showed that DcR3 promoted the growth and spread of endometrium, whereas knockdown of DcR3 by lentivirus-delivered short hairpin RNA inhibited ectopic adhesion of endometrium and abrogated endometriosis progression. These observations are in support of DcR3 playing a critical role in the pathogenesis of endometriosis, and the inhibition of DcR3 expression being a promising approach for the treatment of endometriosis. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Aberrant adhesion impacts early development in a Dictyostelium model for juvenile neuronal ceroid lipofuscinosis

PubMed Central

Huber, Robert J.; Myre, Michael A.; Cotman, Susan L.

2017-01-01

ABSTRACT Neuronal ceroid lipofuscinosis (NCL), also known as Batten disease, refers to a group of severe neurodegenerative disorders that primarily affect children. The most common subtype of the disease is caused by loss-of-function mutations in CLN3, which is conserved across model species from yeast to human. The precise function of the CLN3 protein is not known, which has made targeted therapy development challenging. In the social amoeba Dictyostelium discoideum, loss of Cln3 causes aberrant mid-to-late stage multicellular development. In this study, we show that Cln3-deficiency causes aberrant adhesion and aggregation during the early stages of Dictyostelium development. cln3− cells form ∼30% more multicellular aggregates that are comparatively smaller than those formed by wild-type cells. Loss of Cln3 delays aggregation, but has no significant effect on cell speed or cAMP-mediated chemotaxis. The aberrant aggregation of cln3− cells cannot be corrected by manually pulsing cells with cAMP. Moreover, there are no significant differences between wild-type and cln3− cells in the expression of genes linked to cAMP chemotaxis (e.g., adenylyl cyclase, acaA; the cAMP receptor, carA; cAMP phosphodiesterase, pdsA; g-protein α 9 subunit, gpaI). However, during this time in development, cln3− cells show reduced cell-substrate and cell-cell adhesion, which correlate with changes in the levels of the cell adhesion proteins CadA and CsaA. Specifically, loss of Cln3 decreases the intracellular level of CsaA and increases the amount of soluble CadA in conditioned media. Together, these results suggest that the aberrant aggregation of cln3− cells is due to reduced adhesion during the early stages of development. Revealing the molecular basis underlying this phenotype may provide fresh new insight into CLN3 function. PMID:27669405

Effect of salivary secretory IgA on the adhesion of Candida albicans to polystyrene.

PubMed

San Millán, R; Elguezabal, N; Regúlez, P; Moragues, M D; Quindós, G; Pontón, J

2000-09-01

Attachment of Candida albicans to plastic materials of dental prostheses or to salivary macromolecules adsorbed on their surface is believed to be a critical event in the development of denture stomatitis. In an earlier study, it was shown that adhesion of C. albicans to polystyrene, a model system to study the adhesion of C. albicans to plastic materials, can be partially inhibited with an mAb directed against cell wall polysaccharides of C. albicans. In the present study, the role of whole saliva in the adhesion of C. albicans to polystyrene has been investigated, and three mAbs directed against epitopes of cell wall mannoproteins have been used to mimic the inhibitory effect observed with salivary secretory IgA (sIgA) on the adhesion of C. albicans to polystyrene. In the absence of whole saliva, adherence of C. albicans 3153 increased with germination. However, the presence of whole saliva enhanced the adhesion to polystyrene of C. albicans 3153 yeast cells but decreased the adhesion of germinated cells. The enhancement of adhesion of yeast cells to polystyrene mediated by saliva was confirmed with an agerminative mutant of C. albicans 3153. The inhibition of the adhesion of C. albicans 3153 germ tubes to polystyrene was due to the salivary sIgA since sIgA-depleted saliva enhanced the adhesion of C. albicans 3153 to polystyrene. The inhibitory effect mediated by sIgA was not related to the inhibition of germination but to the blockage of adhesins expressed on the cell wall surface of the germ tubes. The three mAbs studied reduced the adhesion of C. albicans 3153 to polystyrene at levels equivalent to those for purified sIgA. The highest reduction in the adhesion was obtained with the IgA mAb N3B. The best results were obtained when the three mAbs were combined. The results suggest that whole saliva plays a different role in the adhesion of C. albicans to polystyrene depending on the morphological phase of C. albicans. These results may give new insights into the conflicting role of saliva in the adhesion of C. albicans to plastic materials of dental prostheses.

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

PubMed

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

2013-01-01

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

The melanocortin receptor agonist NDP-MSH impairs the allostimulatory function of dendritic cells.

PubMed

Rennalls, La'Verne P; Seidl, Thomas; Larkin, James M G; Wellbrock, Claudia; Gore, Martin E; Eisen, Tim; Bruno, Ludovica

2010-04-01

As alpha-melanocyte-stimulating hormone (alpha-MSH) is released by immunocompetent cells and has potent immunosuppressive properties, it was determined whether human dendritic cells (DCs) express the receptor for this hormone. Reverse transcription-polymerase chain reaction detected messenger RNA specific for all of the known melanocortin receptors in DCs. Mixed lymphocyte reactions also revealed that treatment with [Nle(4), DPhe(7)]-alpha-MSH (NDP-MSH), a potent alpha-MSH analogue, significantly reduced the ability of DCs to stimulate allogeneic T cells. The expression of various cell surface adhesion, maturation and costimulatory molecules on DCs was also investigated. Although treatment with NDP-MSH did not alter the expression of CD83 and major histocompatibility complex class I and II, the surface expression of CD86 (B7.2), intercellular adhesion molecule (ICAM-1/CD54) and CD1a was reduced. In summary, our data indicate that NDP-MSH inhibits the functional activity of DCs, possibly by down-regulating antigen-presenting and adhesion molecules and that these events may be mediated via the extracellular signal-regulated kinase 1 and 2 pathway.

DEVELOPMENT OF A MODEL TO INVESTIGATE RED BLOOD CELL SURFACE CHARACTERISTICS AFTER CRYOPRESERVATION.

PubMed

Gordiyenko, O I; Anikieieva, M O; Rozanova, S L; Kovalenko, S Ye; Kovalenkol, I F; Gordiyenko, E O

2015-01-01

Maintaining cell surface properties after freezing and thawing, characterized in particular by the surface potential and associated with it cell ability to intercellular adhesion, could be used as a characteristic of successful cryopreservation. This study was conducted to research applying different erythrocytes freezing modes and analyses the regimes cryopreservation effect on the cell surface charge and adhesion to microorganisms. Human erythrocytes frozen by three modes. In order to determine adhesion index was used dried bacterial cells of S. thermophilus. The surface charge of erythrocytes was evaluated using Alcian blue cationic dye. The results showed the significant decrease in the lactobacillus adhesion to erythrocytes frozen glycerol and 1,2-propanediol. After erythrocytes were freezen with glycerol and 1,2-propanediol, the cationic dye binding to erythrocytes significantly reduced. AB binding to erythrocytes frozen with PEG-1500 does not differ from control data. Erythrocytes frozen with PEG-1500 mantained surface properties after thawing better, compared to erythrocytes cryopreserved by other methods.

West Nile virus-induced cell adhesion molecules on human brain microvascular endothelial cells regulate leukocyte adhesion and modulate permeability of the in vitro blood-brain barrier model.

PubMed

Roe, Kelsey; Orillo, Beverly; Verma, Saguna

2014-01-01

Characterizing the mechanisms by which West Nile virus (WNV) causes blood-brain barrier (BBB) disruption, leukocyte infiltration into the brain and neuroinflammation is important to understand the pathogenesis of WNV encephalitis. Here, we examined the role of endothelial cell adhesion molecules (CAMs) in mediating the adhesion and transendothelial migration of leukocytes across human brain microvascular endothelial cells (HBMVE). Infection with WNV (NY99 strain) significantly induced ICAM-1, VCAM-1, and E-selectin in human endothelial cells and infected mice brain, although the levels of their ligands on leukocytes (VLA-4, LFA-1and MAC-1) did not alter. The permeability of the in vitro BBB model increased dramatically following the transmigration of monocytes and lymphocytes across the models infected with WNV, which was reversed in the presence of a cocktail of blocking antibodies against ICAM-1, VCAM-1, and E-selectin. Further, WNV infection of HBMVE significantly increased leukocyte adhesion to the HBMVE monolayer and transmigration across the infected BBB model. The blockade of these CAMs reduced the adhesion and transmigration of leukocytes across the infected BBB model. Further, comparison of infection with highly neuroinvasive NY99 and non-lethal (Eg101) strain of WNV demonstrated similar level of virus replication and fold-increase of CAMs in HBMVE cells suggesting that the non-neuropathogenic response of Eg101 is not because of its inability to infect HBMVE cells. Collectively, these results suggest that increased expression of specific CAMs is a pathological event associated with WNV infection and may contribute to leukocyte infiltration and BBB disruption in vivo. Our data further implicate that strategies to block CAMs to reduce BBB disruption may limit neuroinflammation and virus-CNS entry via 'Trojan horse' route, and improve WNV disease outcome.

Chlorella 11-Peptide Inhibits the Production of Macrophage-Induced Adhesion Molecules and Reduces Endothelin-1 Expression and Endothelial Permeability

PubMed Central

Shih, Mei Fen; Chen, Lih Chi; Cherng, Jong Yuh

2013-01-01

The inflammation process in large vessels involves the up-regulation of vascular adhesion molecules such as endothelial cell selectin (E-selectin), intercellular cell adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) which are also known as the markers of atherosclerosis. We have reported that Chlorella 11-peptide exhibited effective anti-inflammatory effects. This peptide with an amino sequence Val-Glu-Cys-Tyr-Gly-Pro-Asn-Arg-Pro-Gln-Phe was further examined for its potential in preventing atherosclerosis in this study. In particular, the roles of Chlorella 11-peptide in lowering the production of vascular adhesion molecules, monocyte chemoattractant protein (MCP-1) and expression of endothelin-1 (ET-1) from endothelia (SVEC4-10 cells) were studied. The production of E-selectin, ICAM-1, VCAM-1 and MCP-1 in SVEC4-10 cells was measured with ELISA. The mRNA expression of ET-1 was analyzed by RT-PCR and agarose gel. Results showed that Chlorella 11-peptide significantly suppressed the levels of E-selectin, ICAM, VCAM, MCP-1 as well as ET-1 gene expression. The inhibition of ICAM-1 and VCAM-1 production by Chlorella 11-peptide was reversed in the presence of protein kinase A inhibitor (H89) which suggests that the cAMP pathway was involved in the inhibitory cause of the peptide. In addition, this peptide was shown to reduce the extent of increased intercellular permeability induced by combination of 50% of lipopolysaccharide (LPS)-activated RAW 264.7 cells medium and 50% normal SEVC cell culture medium (referred to as 50% RAW-conditioned medium). These data demonstrate that Chlorella 11-peptide is a promising biomolecule in preventing chronic inflammatory-related vascular diseases. PMID:24129228

Mapping the Dynamics of Shear Stress—Induced Structural Changes in Endothelial Cells

PubMed Central

Mott, Rosalind E.; Helmke, Brian P.

2009-01-01

Hemodynamic shear stress regulates endothelial cell biochemical processes that govern cytoskeletal contractility, focal adhesion dynamics, and extracellular matrix assembly. Since shear stress causes rapid strain focusing at discrete locations in the cytoskeleton, we hypothesized that shear stress coordinately alters structural dynamics in the cytoskeleton, focal adhesion sites, and extracellular matrix on a time scale of minutes. Using multi-wavelength 4-D fluorescence microscopy, we measured the displacement of rhodamine-fibronectin and of GFP-labeled actin, vimentin, paxillin, and/or vinculin in aortic endothelial cells before and after onset of steady unidirectional shear stress. In the cytoskeleton, the onset of shear stress increased actin polymerization into lamellipodia, altered the angle of lateral displacement of actin stress fibers and vimentin filaments, and decreased centripetal remodeling of actin stress fibers in both subconfluent and confluent cell layers. Shear stress induced the formation of new focal complexes and reduced the centripetal remodeling of focal adhesions in regions of new actin polymerization. The structural dynamics of focal adhesions and the fibronectin matrix varied with cell density. In subconfluent cell layers, shear stress onset decreased the displacement of focal adhesions and fibronectin fibrils. In confluent monolayers, the direction of fibronectin and focal adhesion displacement shifted significantly towards the downstream direction within one minute after onset of shear stress. These spatially coordinated rapid changes in the structural dynamics of cytoskeleton, focal adhesions, and extracellular matrix are consistent with focusing of mechanical stress and/or strain near major sites of shear stress-mediated mechanotransduction. PMID:17855768

Imprint Molding of a Microfluidic Optical Cell on Thermoplastics with Reduced Surface Roughness for the Detection of Copper Ions.

PubMed

Wu, Jing; Lee, Nae Yoon

2016-01-01

Here, we introduce a simple and facile technique for fabricating microfluidic optical cells by utilizing a micropatterned polymer mold, followed by imprinting on thermoplastic substrates. This process has reduced the surface roughness of the microchannel, making it suitable for microscale optical measurements. The micropatterned polymer mold was fabricated by first micromilling on a poly(methylmethacrylate) (PMMA) substrate, and then transferring the micropattern onto an ultraviolet (UV)-curable optical adhesive. After an anti-adhesion treatment of the polymer mold fabricated using the UV-curable optical adhesive, the polymer mold was used repeatedly for imprinting onto various thermoplastics, such as PMMA, polycarbonate (PC), and poly(ethyleneterephthalate) (PET). The roughness values for the PMMA, PC, and PET microchannels were approximately 11.3, 20.3, and 14.2 nm, respectively, as compared to those obtained by micromilling alone, which were 15.9, 76.8, and 207.5 nm, respectively. Using the imprint-molded thermoplastic optical cell, rhodamine B and copper ions were successfully quantified. The reduced roughness of the microchannel surface resulted in improved sensitivity and reduced noise, paving the way for integration of the detection module so as to realize totally integrated microdevices.

Downregulation of connective tissue growth factor by three-dimensional matrix enhances ovarian carcinoma cell invasion.

PubMed

Barbolina, Maria V; Adley, Brian P; Kelly, David L; Shepard, Jaclyn; Fought, Angela J; Scholtens, Denise; Penzes, Peter; Shea, Lonnie D; Stack, M Sharon

2009-08-15

Epithelial ovarian carcinoma (EOC) is a leading cause of death from gynecologic malignancies, due mainly to the prevalence of undetected metastatic disease. The process of cell invasion during intraperitoneal anchoring of metastatic lesions requires concerted regulation of many processes, including modulation of adhesion to the extracellular matrix and localized invasion. Exploratory cDNA microarray analysis of early response genes (altered after 4 hr of 3D collagen culture) coupled with confirmatory real-time reverse-transcriptase polymerase chain reaction, multiple 3D cell culture matrices, Western blot, immunostaining, adhesion, migration and invasion assays were used to identify modulators of adhesion pertinent to EOC progression and metastasis. cDNA microarray analysis indicated a dramatic downregulation of connective tissue growth factor (CTGF) in EOC cells placed in invasion- mimicking conditions (3D Type I collagen). Examination of human EOC specimens revealed that CTGF expression was absent in 46% of the tested samples (n = 41), but was present in 100% of normal ovarian epithelium samples (n = 7). Reduced CTGF expression occurs in many types of cells and may be a general phenomenon displayed by cells encountering a 3D environment. CTGF levels were inversely correlated with invasion such that downregulation of CTGF increased, while its upregulation reduced collagen invasion. Cells adhered preferentially to a surface comprised of both collagen I and CTGF relative to either component alone using alpha6beta1 and alpha3beta1 integrins. Together these data suggest that downregulation of CTGF in EOC cells may be important for cell invasion through modulation of cell-matrix adhesion.

Downregulation of Connective Tissue Growth Factor by Three-Dimensional Matrix Enhances Ovarian Carcinoma Cell Invasion

PubMed Central

Barbolina, Maria V.; Adley, Brian P.; Kelly, David L.; Shepard, Jaclyn; Fought, Angela J.; Scholtens, Denise; Penzes, Peter; Shea, Lonnie D.; Sharon Stack, M

2010-01-01

Epithelial ovarian carcinoma (EOC) is a leading cause of death from gynecologic malignancy, due mainly to the prevalence of undetected metastatic disease. The process of cell invasion during intra-peritoneal anchoring of metastatic lesions requires concerted regulation of many processes, including modulation of adhesion to the extracellular matrix and localized invasion. Exploratory cDNA microarray analysis of early response genes (altered after 4 hours of 3-dimensional collagen culture) coupled with confirmatory real-time RT-PCR, multiple three-dimensional cell culture matrices, Western blot, immunostaining, adhesion, migration, and invasion assays were used to identify modulators of adhesion pertinent to EOC progression and metastasis. cDNA microarray analysis indicated a dramatic downregulation of connective tissue growth factor (CTGF) in EOC cells placed in invasion-mimicking conditions (3-dimensional type I collagen). Examination of human EOC specimens revealed that CTGF expression was absent in 46% of the tested samples (n=41), but was present in 100% of normal ovarian epithelium samples (n=7). Reduced CTGF expression occurs in many types of cells and may be a general phenomenon displayed by cells encountering a 3D environment. CTGF levels were inversely correlated with invasion such that downregulation of CTGF increased, while its upregulation reduced, collagen invasion. Cells adhered preferentially to a surface comprised of both collagen I and CTGF relative to either component alone using α6β1 and α3β1 integrins. Together these data suggest that downregulation of CTGF in EOC cells may be important for cell invasion through modulation of cell-matrix adhesion. PMID:19382180

Endogenous production of fibronectin is required for self-renewal of cultured mouse embryonic stem cells

PubMed Central

Hunt, Geoffrey C.; Singh, Purva; Schwarzbauer, Jean E.

2012-01-01

Pluripotent cells are attached to the extracellular matrix (ECM) as they make cell fate decisions within the stem cell niche. Here we show that the ubiquitous ECM protein fibronectin is required for self-renewal decisions by cultured mouse embryonic stem (mES) cells. Undifferentiated mES cells produce fibronectin and assemble a fibrillar matrix. Increasing the level of substrate fibronectin increased cell spreading and integrin receptor signaling through focal adhesion kinase, while concomitantly inducing the loss of Nanog and Oct4 self-renewal markers. Conversely, reducing fibronectin production by mES cells growing on a feeder-free gelatin substrate caused loss of cell adhesion, decreased integrin signaling, and decreased expression of self-renewal markers. These effects were reversed by providing the cells with exogenous fibronectin, thereby restoring adhesion to the gelatin substrate. Interestingly, mES cells do not adhere directly to the gelatin substrate, but rather adhere indirectly through gelatin-bound fibronectin, which facilitates self-renewal via its effects on cell adhesion. These results provide new insights into the mechanism of regulation of self-renewal by growth on a gelatin-coated surface. The effects of increasing or decreasing fibronectin levels show that self-renewal depends on an intermediate level of cell-fibronectin interactions. By providing cell adhesive signals that can act with other self-renewal factors to maintain mES cell pluripotency, fibronectin is therefore a necessary component of the self-renewal signaling pathway in culture. PMID:22710062

Endogenous production of fibronectin is required for self-renewal of cultured mouse embryonic stem cells.

PubMed

Hunt, Geoffrey C; Singh, Purva; Schwarzbauer, Jean E

2012-09-10

Pluripotent cells are attached to the extracellular matrix (ECM) as they make cell fate decisions within the stem cell niche. Here we show that the ubiquitous ECM protein fibronectin is required for self-renewal decisions by cultured mouse embryonic stem (mES) cells. Undifferentiated mES cells produce fibronectin and assemble a fibrillar matrix. Increasing the level of substrate fibronectin increased cell spreading and integrin receptor signaling through focal adhesion kinase, while concomitantly inducing the loss of Nanog and Oct4 self-renewal markers. Conversely, reducing fibronectin production by mES cells growing on a feeder-free gelatin substrate caused loss of cell adhesion, decreased integrin signaling, and decreased expression of self-renewal markers. These effects were reversed by providing the cells with exogenous fibronectin, thereby restoring adhesion to the gelatin substrate. Interestingly, mES cells do not adhere directly to the gelatin substrate, but rather adhere indirectly through gelatin-bound fibronectin, which facilitates self-renewal via its effects on cell adhesion. These results provide new insights into the mechanism of regulation of self-renewal by growth on a gelatin-coated surface. The effects of increasing or decreasing fibronectin levels show that self-renewal depends on an intermediate level of cell-fibronectin interactions. By providing cell adhesive signals that can act with other self-renewal factors to maintain mES cell pluripotency, fibronectin is therefore a necessary component of the self-renewal signaling pathway in culture. Copyright © 2012 Elsevier Inc. All rights reserved.

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

PubMed

Moral, Mario E G; Siahaan, Teruna J

2017-01-01

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

Baicalein inhibits the migration and invasive properties of human hepatoma cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chiu, Yung-Wei; Institute of Medicine, Chung Shan Medical University, Taiwan; Lin, Tseng-Hsi

Flavonoids have been demonstrated to exert health benefits in humans. We investigated whether the flavonoid baicalein would inhibit the adhesion, migration, invasion, and growth of human hepatoma cell lines, and we also investigated its mechanism of action. The separate effects of baicalein and baicalin on the viability of HA22T/VGH and SK-Hep1 cells were investigated for 24 h. To evaluate their invasive properties, cells were incubated on matrigel-coated transwell membranes in the presence or absence of baicalein. We examined the effect of baicalein on the adhesion of cells, on the activation of matrix metalloproteinases (MMPs), protein kinase C (PKC), and p38more » mitogen-activated protein kinase (MAPK), and on tumor growth in vivo. We observed that baicalein suppresses hepatoma cell growth by 55%, baicalein-treated cells showed lower levels of migration than untreated cells, and cell invasion was significantly reduced to 28%. Incubation of hepatoma cells with baicalein also significantly inhibited cell adhesion to matrigel, collagen I, and gelatin-coated substrate. Baicalein also decreased the gelatinolytic activities of the matrix metalloproteinases MMP-2, MMP-9, and uPA, decreased p50 and p65 nuclear translocation, and decreased phosphorylated I-kappa-B (IKB)-{beta}. In addition, baicalein reduced the phosphorylation levels of PKC{alpha} and p38 proteins, which regulate invasion in poorly differentiated hepatoma cells. Finally, when SK-Hep1 cells were grown as xenografts in nude mice, intraperitoneal (i.p.) injection of baicalein induced a significant dose-dependent decrease in tumor growth. These results demonstrate the anticancer properties of baicalein, which include the inhibition of adhesion, invasion, migration, and proliferation of human hepatoma cells in vivo. - Highlight: > Baicalein inhibits several essential steps in the onset of metastasis.« less

Distinct roles for paxillin and Hic-5 in regulating breast cancer cell morphology, invasion, and metastasis

PubMed Central

Deakin, Nicholas O.; Turner, Christopher E.

2011-01-01

Individual metastatic tumor cells exhibit two interconvertible modes of cell motility during tissue invasion that are classified as either mesenchymal or amoeboid. The molecular mechanisms by which invasive breast cancer cells regulate this migratory plasticity have yet to be fully elucidated. Herein we show that the focal adhesion adaptor protein, paxillin, and the closely related Hic-5 have distinct and unique roles in the regulation of breast cancer cell lung metastasis by modulating cell morphology and cell invasion through three-dimensional extracellular matrices (3D ECMs). Cells depleted of paxillin by RNA interference displayed a highly elongated mesenchymal morphology, whereas Hic-5 knockdown induced an amoeboid phenotype with both cell populations exhibiting reduced plasticity, migration persistence, and velocity through 3D ECM environments. In evaluating associated signaling pathways, we determined that Rac1 activity was increased in cells devoid of paxillin whereas Hic-5 silencing resulted in elevated RhoA activity and associated Rho kinase–induced nonmuscle myosin II activity. Hic-5 was essential for adhesion formation in 3D ECMs, and analysis of adhesion dynamics and lifetime identified paxillin as a key regulator of 3D adhesion assembly, stabilization, and disassembly. PMID:21148292

Characterization of Adhesives for Attaching Reusable Surface Insulation on Space Shuttle Vehicles

NASA Technical Reports Server (NTRS)

Owen, H. P.; Carroll, M. T.

1973-01-01

An extensive development and testing program on adhesive systems shows that: (1) A closed cell silicone rubber sponge bonded to substrates with thin bond lines of glass filled adhesive exhibits density and modulus values approximately one third that of solid silicone adhesives; (2) utilization of glass or phenolic microballoons as fillers in silicone adhesives reduces density but increases moduli of the vulcanized materials; (3) the silicone elastomer based adhesives appear to be complex systems rather than homogeneous, isotropic materials. Tensile, shear, and compression properties plotted versus temperature verify this conjecture; and (4) constant strain-stress relaxation tests on glass-filled adhesive show that stress relaxation is most pronounced near the glass transition temperature.

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

PubMed

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

2015-02-15

We previously demonstrated that the expression of intercellular adhesion molecule-1 (ICAM-1) by skeletal muscle cells after muscle overload contributes to ensuing regenerative and hypertrophic processes in skeletal muscle. The objective of the present study is to reveal mechanisms through which skeletal muscle cell expression of ICAM-1 augments regenerative and hypertrophic processes of myogenesis. This was accomplished by genetically engineering C2C12 myoblasts to stably express ICAM-1, and by inhibiting the adhesive and signaling functions of ICAM-1 through the use of a neutralizing antibody or cell penetrating peptide, respectively. Expression of ICAM-1 by cultured skeletal muscle cells augmented myoblast-myoblast adhesion, myotube formation, myonuclear number, myotube alignment, myotube-myotube fusion, and myotube size without influencing the ability of myoblasts to proliferate or differentiate. ICAM-1 augmented myotube formation, myonuclear accretion, and myotube alignment through a mechanism involving adhesion-induced activation of ICAM-1 signaling, as these dependent measures were reduced via antibody and peptide inhibition of ICAM-1. The adhesive and signaling functions of ICAM-1 also facilitated myotube hypertrophy through a mechanism involving myotube-myotube fusion, protein synthesis, and Akt/p70s6k signaling. Our findings demonstrate that ICAM-1 expression by skeletal muscle cells augments myogenesis, and establish a novel mechanism through which the inflammatory response facilitates growth processes in skeletal muscle. Copyright © 2014 Elsevier Inc. All rights reserved.

Intercellular Adhesion Molecule-1 Expression by Skeletal Muscle Cells Augments Myogenesis

PubMed Central

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

2014-01-01

We previously demonstrated that the expression of intercellular adhesion molecule-1 (ICAM-1) by skeletal muscle cells after muscle overload contributes to ensuing regenerative and hypertrophic processes in skeletal muscle. The objective of the present study is to reveal mechanisms through which skeletal muscle cell expression of ICAM-1 augments regenerative and hypertrophic processes of myogenesis. This was accomplished by genetically engineering C2C12 myoblasts to stably express ICAM-1, and by inhibiting the adhesive and signaling functions of ICAM-1 through the use of a neutralizing antibody or cell penetrating peptide, respectively. Expression of ICAM-1 by cultured skeletal muscle cells augmented myoblast-myoblast adhesion, myotube formation, myonuclear number, myotube alignment, myotube-myotube fusion, and myotube size without influencing the ability of myoblasts to proliferate or differentiate. ICAM-1 augmented myotube formation, myonuclear accretion, and myotube alignment through a mechanism involving adhesion-induced activation of ICAM-1 signaling, as these dependent measures were reduced via antibody and peptide inhibition of ICAM-1. The adhesive and signaling functions of ICAM-1 also facilitated myotube hypertrophy through a mechanism involving myotube-myotube fusion, protein synthesis, and Akt/p70s6k signaling. Our findings demonstrate that ICAM-1 expression by skeletal muscle cells augments myogenesis, and establish a novel mechanism through which the inflammatory response facilitates growth processes in skeletal muscle. PMID:25281303

Inhibition of cell migration by focal adhesion kinase: Time-dependent difference in integrin-induced signaling between endothelial and hepatoblastoma cells.

PubMed

Yu, Hongchi; Gao, Min; Ma, Yunlong; Wang, Lijuan; Shen, Yang; Liu, Xiaoheng

2018-05-01

angiogenesis plays an important role in the development and progression of tumors, and it involves a series of signaling pathways contributing to the migration of endothelial cells for vascularization and to the invasion of cancer cells for secondary tumor formation. Among these pathways, the focal adhesion kinase (FAK) signaling cascade has been implicated in a variety of human cancers in connection with cell adhesion and migration events leading to tumor angiogenesis, metastasis and invasion. Therefore, the inhibition of FAK in endothelial and/or cancer cells is a potential target for anti‑angiogenic therapy. In the present study, a small‑molecule FAK inhibitor, 1,2,4,5-benzenetetramine tetrahydrochloride (Y15), was used to study the effects of FAK inhibition on the adhesion and migration behaviors of vascular endothelial cells (VECs) and human hepatoblastoma cells. Furthermore, the time-dependent differences in proteins associated with the integrin-mediated FAK/Rho GTPases signaling pathway within 2 h were examined. The results indicated that the inhibition of FAK significantly decreased the migration ability of VECs and human hepatoblastoma cells in a dose-dependent manner. Inhibition of FAK promoted cell detachment by decreasing the expression of focal adhesion components, and blocked cell motility by reducing the level of Rho GTPases. However, the expression of crucial proteins involved in integrin-induced signaling in two cell lines exhibited a time-dependent difference with increased duration of FAK inhibitor treatment, suggesting different mechanisms of FAK-mediated cell migration behavior. These results suggest that the mechanism underlying FAK-mediated adhesion and migration behavior differs among various cells, which is expected to provide evidence for future FAK therapy targeted against tumor angiogenesis.

Peptide array-based interaction assay of solid-bound peptides and anchorage-dependant cells and its effectiveness in cell-adhesive peptide design.

PubMed

Kato, Ryuji; Kaga, Chiaki; Kunimatsu, Mitoshi; Kobayashi, Takeshi; Honda, Hiroyuki

2006-06-01

Peptide array, the designable peptide library covalently synthesized on cellulose support, was applied to assay peptide-cell interaction, between solid-bound peptides and anchorage-dependant cells, to study objective peptide design. As a model case, cell-adhesive peptides that could enhance cell growth as tissue engineering scaffold material, was studied. On the peptide array, the relative cell-adhesion ratio of NIH/3T3 cells was 2.5-fold higher on the RGDS (Arg-Gly-Asp-Ser) peptide spot as compared to the spot with no peptide, thus indicating integrin-mediated peptide-cell interaction. Such strong cell adhesion mediated by the RGDS peptide was easily disrupted by single residue substitution on the peptide array, thus indicating that the sequence recognition accuracy of cells was strictly conserved in our optimized scheme. The observed cellular morphological extension with active actin stress-fiber on the RGD motif-containing peptide supported our strategy that peptide array-based interaction assay of solid-bound peptide and anchorage-dependant cells (PIASPAC) could provide quantitative data on biological peptide-cell interaction. The analysis of 180 peptides obtained from fibronectin type III domain (no. 1447-1629) yielded 18 novel cell-adhesive peptides without the RGD motif. Taken together with the novel candidates, representative rules of ineffective amino acid usage were obtained from non-effective candidate sequences for the effective designing of cell-adhesive peptides. On comparing the amino acid usage of the top 20 and last 20 peptides from the 180 peptides, the following four brief design rules were indicated: (i) Arg or Lys of positively charged amino acids (except His) could enhance cell adhesion, (ii) small hydrophilic amino acids are favored in cell-adhesion peptides, (iii) negatively charged amino acids and small amino acids (except Gly) could reduce cell adhesion, and (iv) Cys and Met could be excluded from the sequence combination since they have less influence on the peptide design. Such rules that are indicative of the nature of the functional peptide sequence can be obtained only by the mass comparison analysis of PIASPAC using peptide array. By following such indicative rules, numerous amino acid combinations can be effectively screened for further examination of novel peptide design.

Collisions of deformable cells lead to collective migration

DOE PAGES

Löber, Jakob; Ziebert, Falko; Aranson, Igor S.

2015-03-17

Collective migration of eukaryotic cells plays a fundamental role in tissue growth, wound healing and immune response. The motion, arising spontaneously or in response to chemical and mechanical stimuli, is also important for understanding life-threatening pathologies, such as cancer and metastasis formation. We present a phase-field model to describe the movement of many self-organized, interacting cells. The model takes into account the main mechanisms of cell motility – acto-myosin dynamics, as well as substrate-mediated and cell-cell adhesion. It predicts that collective cell migration emerges spontaneously as a result of inelastic collisions between neighboring cells: collisions lead to a mutual alignmentmore » of the cell velocities and to the formation of coherently-moving multi-cellular clusters. Small cell-to-cell adhesion, in turn, reduces the propensity for large-scale collective migration, while higher adhesion leads to the formation of moving bands. Our study provides valuable insight into biological processes associated with collective cell motility.« less

Collisions of deformable cells lead to collective migration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Löber, Jakob; Ziebert, Falko; Aranson, Igor S.

Collective migration of eukaryotic cells plays a fundamental role in tissue growth, wound healing and immune response. The motion, arising spontaneously or in response to chemical and mechanical stimuli, is also important for understanding life-threatening pathologies, such as cancer and metastasis formation. We present a phase-field model to describe the movement of many self-organized, interacting cells. The model takes into account the main mechanisms of cell motility – acto-myosin dynamics, as well as substrate-mediated and cell-cell adhesion. It predicts that collective cell migration emerges spontaneously as a result of inelastic collisions between neighboring cells: collisions lead to a mutual alignmentmore » of the cell velocities and to the formation of coherently-moving multi-cellular clusters. Small cell-to-cell adhesion, in turn, reduces the propensity for large-scale collective migration, while higher adhesion leads to the formation of moving bands. Our study provides valuable insight into biological processes associated with collective cell motility.« less

Function-blocking antibodies to human vascular adhesion protein-1: a potential anti-inflammatory therapy.

PubMed

Kirton, Christopher M; Laukkanen, Marja-Leena; Nieminen, Antti; Merinen, Marika; Stolen, Craig M; Armour, Kathryn; Smith, David J; Salmi, Marko; Jalkanen, Sirpa; Clark, Michael R

2005-11-01

Human vascular adhesion protein-1 (VAP-1) is a homodimeric 170-kDa sialoglycoprotein that is expressed on the surface of endothelial cells and functions as a semicarbazide-sensitive amine oxidase and as an adhesion molecule. Blockade of VAP-1 has been shown to reduce leukocyte adhesion and transmigration in in vivo and in vitro models, suggesting that VAP-1 is a potential target for anti-inflammatory therapy. In this study we have constructed mouse-human chimeric antibodies by genetic engineering in order to circumvent the potential problems involved in using murine antibodies in man. Our chimeric anti-VAP-1 antibodies, which were designed to lack Fc-dependent effector functions, bound specifically to cell surface-expressed recombinant human VAP-1 and recognized VAP-1 in different cell types in tonsil. Furthermore, the chimeric antibodies prevented leukocyte adhesion and transmigration in vitro and in vivo. Hence, these chimeric antibodies have the potential to be used as a new anti-inflammatory therapy.

Small angle neutron scattering as a tool to evaluate moisture-induced swelling in the nanostructure of chemically modified wood cell walls

Treesearch

Nayomi Z. Plaza; Joseph E. Jakes; Charles R. Frihart; Christopher G. Hunt; Daniel J. Yelle; Linda F. Lorenz

2017-01-01

Wood-based products can be a sustainable and more environmentally friendly alternative to traditional construction materials because of their reduced contribution to air and water pollution. An integral component of these products is often an adhesive. Because wood is hygroscopic, moisture-induced swelling in the cell walls near the wood– adhesive bondlines can lead to...

Ionic requirements for membrane-glass adhesion and giga seal formation in patch-clamp recording.

PubMed

Priel, Avi; Gil, Ziv; Moy, Vincent T; Magleby, Karl L; Silberberg, Shai D

2007-06-01

Patch-clamp recording has revolutionized the study of ion channels, transporters, and the electrical activity of small cells. Vital to this method is formation of a tight seal between glass recording pipette and cell membrane. To better understand seal formation and improve practical application of this technique, we examine the effects of divalent ions, protons, ionic strength, and membrane proteins on adhesion of membrane to glass and on seal resistance using both patch-clamp recording and atomic force microscopy. We find that H(+), Ca(2+), and Mg(2+) increase adhesion force between glass and membrane (lipid and cellular), decrease the time required to form a tight seal, and increase seal resistance. In the absence of H(+) (10(-10) M) and divalent cations (<10(-8) M), adhesion forces are greatly reduced and tight seals are not formed. H(+) (10(-7) M) promotes seal formation in the absence of divalent cations. A positive correlation between adhesion force and seal formation indicates that high resistance seals are associated with increased adhesion between membrane and glass. A similar ionic dependence of the adhesion of lipid membranes and cell membranes to glass indicates that lipid membranes without proteins are sufficient for the action of ions on adhesion.

Increased ICAM-1 Expression in Transformed Human Oral Epithelial Cells: Molecular Mechanism and Functional Role in Peripheral Blood Mononuclear Cell Adhesion and Lymphokine-Activated-Killer Cell Cytotoxicity

PubMed Central

Huang, George T.-J.; Zhang, Xinli; Park, No-Hee

2012-01-01

The intercellular adhesion molecule-1 (ICAM-1, CD54) serves as a counter-receptor for the β2-integrins, LFA-1 and Mac-1, which are expressed on leukocytes. Although expression of ICAM-1 on tumor cells has a role in tumor progression and development, information on ICAM-1 expression and its role in oral cancer has not been established. Normal human oral keratinocytes (NHOK), human papilloma virus (HPV)-immortalized human oral keratinocyte lines (HOK-16B, HOK-18A, and HOK-18C), and six human oral neoplastic cell lines (HOK-16B-BaP-T1, SCC-4, SCC-9, HEp-2, Tu-177 and 1483) were used to study ICAM-1 expression and its functional role in vitro. Our results demonstrated that NHOK express negligible levels of ICAM-1, whereas immortalized human oral keratinocytes and cancer cells express significantly higher levels of ICAM-1, except for HOK-16B-BaP-T1 and HEp-2. Altered mRNA half-lives did not fully account for the increased accumulation of ICAM-1 mRNA. Adhesion of peripheral blood mononuclear cells (PBMC) to epithelial cells correlated with cell surface ICAM-1 expression levels. This adhesion was inhibited by antibodies specific for either ICAM-1 or LFA-1/Mac-1, suggesting a role for these molecules in adhesion. In contrast, lymphokine-activated-killer (LAK) cell cytotoxic killing of epithelial cells did not correlate with ICAM-1 levels or with adhesion. Nonetheless, within each cell line, blocking of ICAM-1 or LFA-1/Mac-1 reduced LAK cells killing, suggesting that ICAM-1 is involved in mediating this killing. PMID:10938387

Predictive modelling of a novel anti-adhesion therapy to combat bacterial colonisation of burn wounds

PubMed Central

Huebinger, Ryan M.; Keen, Emma

2018-01-01

As the development of new classes of antibiotics slows, bacterial resistance to existing antibiotics is becoming an increasing problem. A potential solution is to develop treatment strategies with an alternative mode of action. We consider one such strategy: anti-adhesion therapy. Whereas antibiotics act directly upon bacteria, either killing them or inhibiting their growth, anti-adhesion therapy impedes the binding of bacteria to host cells. This prevents bacteria from deploying their arsenal of virulence mechanisms, while simultaneously rendering them more susceptible to natural and artificial clearance. In this paper, we consider a particular form of anti-adhesion therapy, involving biomimetic multivalent adhesion molecule 7 coupled polystyrene microbeads, which competitively inhibit the binding of bacteria to host cells. We develop a mathematical model, formulated as a system of ordinary differential equations, to describe inhibitor treatment of a Pseudomonas aeruginosa burn wound infection in the rat. Benchmarking our model against in vivo data from an ongoing experimental programme, we use the model to explain bacteria population dynamics and to predict the efficacy of a range of treatment strategies, with the aim of improving treatment outcome. The model consists of two physical compartments: the host cells and the exudate. It is found that, when effective in reducing the bacterial burden, inhibitor treatment operates both by preventing bacteria from binding to the host cells and by reducing the flux of daughter cells from the host cells into the exudate. Our model predicts that inhibitor treatment cannot eliminate the bacterial burden when used in isolation; however, when combined with regular or continuous debridement of the exudate, elimination is theoretically possible. Lastly, we present ways to improve therapeutic efficacy, as predicted by our mathematical model. PMID:29723210

Two Sulfur Glycoside Compounds Isolated from Lepidium apetalum Willd Protect NRK52e Cells against Hypertonic-Induced Adhesion and Inflammation by Suppressing the MAPK Signaling Pathway and RAAS.

PubMed

Yuan, Peipei; Zheng, Xiaoke; Li, Meng; Ke, Yingying; Fu, Yang; Zhang, Qi; Wang, Xiaolan; Feng, Weisheng

2017-11-12

Lepidium apetalum Willd has been used to reduce edema and promote urination. Cis -desulfoglucotropaeolin ( cis -DG) and trans -desulfoglucotropaeolin ( trans -DG) were isolated from Lepidium apetalum Willd, and caused a significant increase in cell viability in a hypertonic model in NRK52e cells. In the hypertonic model, cis -DG and trans -DG significantly promoted the cell viability of NRK52e cells and inhibited the elevation of Na⁺ in the supernatant, inhibited the renin-angiotensin-aldosterone (RAAS) system, significantly reduced the levels of angiotensin II (Ang II) and aldosterone (ALD), and lowered aquaporin-2 (AQP2) and Na⁺-K⁺ ATP content in renal medulla. After treatment with cis -DG and trans -DG, expression of calcineurin (CAN) and Ca/calmodulin-dependent protein kinase II (CaMK II) was decreased in renal tissue and Ca 2+ influx was inhibited, thereby reducing the secretion of transforming growth factor-β (TGFβ), reversing the increase in adhesion and inflammatory factor E-selectin and monocyte chemotactic protein 1 (MCP-1) induced by high NaCl, while reducing oxidative stress status and decreasing the expression of cyclooxygenase-2 (COX2). Furthermore, inhibition of protein kinase C (PKC) expression also contributed to these improvements. The cis -DG and trans -DG reduced the expression of p-p44/42 MAPK, p-JNK and p-p38, inhibited the phosphorylation of the MAPK signaling pathway in NRN52e cells induced by high salt, decreased the overexpression of p-p38 and p-HSP27, and inhibited the overactivation of the p38-MAPK signaling pathway, suggesting that the p38-MAPK pathway may play a vital role in the hypertonic-induced adhesion and inflammatory response. From the results of this study, it can be concluded that the mechanism of cis -DG and trans -DG may mainly be through inhibiting the p38-MAPK signaling pathway, inhibiting the excessive activation of the RAAS system, and thereby reducing adhesion and inflammatory factors.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goh, Qingnian; Dearth, Christopher L.; Corbett, Jacob T.

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

Sundew adhesive: a naturally occurring hydrogel

PubMed Central

Huang, Yujian; Wang, Yongzhong; Sun, Leming; Agrawal, Richa; Zhang, Mingjun

2015-01-01

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

The RhoA/ROCK Pathway Ameliorates Adhesion and Inflammatory Infiltration Induced by AGEs in Glomerular Endothelial Cells.

PubMed

Rao, Jialing; Ye, Zengchun; Tang, Hua; Wang, Cheng; Peng, Hui; Lai, Weiyan; Li, Yin; Huang, Wanbing; Lou, Tanqi

2017-01-05

A recent study demonstrated that advanced glycation end products (AGEs) play a role in monocyte infiltration in mesangial areas in diabetic nephropathy. The Ras homolog gene family, member A Rho kinase (RhoA/ROCK) pathway plays a role in regulating cell migration. We hypothesized that the RhoA/ROCK pathway affects adhesion and inflammation in endothelial cells induced by AGEs. Rat glomerular endothelial cells (rGECs) were cultured with AGEs (80 μg/ml) in vitro. The ROCK inhibitor Y27632 (10 nmol/l) and ROCK1-siRNA were used to inhibit ROCK. We investigated levels of the intercellular adhesion molecule 1 (ICAM-1) and monocyte chemoattractant protein1 (MCP-1) in rGECs. Db/db mice were used as a diabetes model and received Fasudil (10 mg/kg/d, n = 6) via intraperitoneal injection for 12 weeks. We found that AGEs increased the expression of ICAM-1 and MCP-1 in rGECs, and the RhoA/ROCK pathway inhibitor Y27632 depressed the release of adhesion molecules. Moreover, blocking the RhoA/ROCK pathway ameliorated macrophage transfer to the endothelium. Reduced expression of adhesion molecules and amelioration of inflammatory cell infiltration in the glomerulus were observed in db/db mice treated with Fasudil. The RhoA/ROCK pathway plays a role in adhesion molecule expression and inflammatory cell infiltration in glomerular endothelial cells induced by AGEs.

Alteration of pancreatic carcinoma and promyeloblastic cell adhesion in liver microvasculature by co-culture of hepatocytes, hepatic stellate cells and endothelial cells in a physiologically-relevant model.

PubMed

Danoy, Mathieu; Shinohara, Marie; Rizki-Safitri, Astia; Collard, Dominique; Senez, Vincent; Sakai, Yasuyuki

2017-04-18

In vitro models of the liver microvasculature, especially with respect to cancer cell extravasation, should include not only endothelial and cancer cells but also surrounding cells to mimic the physiological situation. To this end, in the present study, we established a physiologically-relevant hierarchical co-culture model by stacking layers of primary rat hepatocytes (Hep), hepatic stellate cells embedded in collagen gel (LX-2) and endothelial cells (HUVECs) on a specially designed oxygen-permeable polydimethylsiloxane PDMS bottom plate. The model was used to investigate the role and contribution of each of the three cell types in pancreatic cancer and promyeloblast cell adhesion. In particular, we showed an increase in albumin production by the primary hepatocytes and in the consumption of the produced vascular endothelial growth factors (VEGFs). Furthermore, in co-culture, the HUVECs exhibited a mature vascular endothelial and non-inflamed phenotype, as evidenced by Stabilin-1, lymphatic vessel endothelial hyaluronan receptor-1 (LYVE-1), intercellular adhesion molecule (ICAM-1), and vascular adhesion protein-1 (VAP-1) expression. The HUVECs were also successfully activated with an inflammatory cytokine and their ICAM-1 response was found to be higher in monoculture compared to co-culture. Additionally, the adhesion of MiaPaCa-2 pancreatic cancer cells and HL60 promyeloblasts was tested in both cases (i.e.: activation or not by an inflammatory cytokine). It has been found that their adhesion was always reduced in the co-culture model. These results highlight the importance of integrating hepatic stellate cells in the design of biomimetic models of the hepatic endothelial barrier.

The low molecular weight Dextran 40 inhibits the adhesion of T lymphocytes to endothelial cells

PubMed Central

TERMEER, C C; WEISS, J M; SCHÖPF, E; VANSCHEIDT, W; SIMON, J C

1998-01-01

Dextrans are complex colloidal macromolecules widely used as haemorrheologic substances and anti-thrombotic agents. Here we describe a novel function of Dextran 40 by demonstrating an inhibition of T lymphocyte adhesion to endothelial cells (EC). We applied an established microassay in which constitutive and tumour necrosis factor-alpha (TNF-α)-induced binding of mouse T lymphoma cells (TK-1) to mouse endothelioma (eEND.2) cells is mediated by the interaction of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) on EC with their counter-receptors the LFA-1 heterodimer (CD11a/CD18) and VLA-4 on T cells. Dextran 40 in therapeutically achievable levels (2–32 mg/ml) reduced both constitutive and TNF-α-stimulated TK-1 adhesion to eEND.2. Selective preincubation of eEND.2 or TK-1 revealed that Dextran 40 acted exclusively on the T cells. To explore further the mechanisms by which Dextran 40 interfered with TK-1 adhesion, their LFA-1 and VLA-4 expression was analysed by FACS. The surface expression levels of neither receptor were affected by Dextran 40. However, confocal microscopy revealed that Dextran 40 interfered with the activation-dependent capping and clustering of LFA-1 and VLA-4 on the surface of TK-1. We conclude that Dextran 40 inhibits the capacity of TK-1 T cells to adhere to eEND.2 endothelial cells and thus may be useful for therapeutic intervention in diseases associated with enhanced T lymphocyte binding to microvascular endothelium. PMID:9844053

Delineating the Tes Interaction Site in Zyxin and Studying Cellular Effects of Its Disruption.

PubMed

Hadzic, Ermin; Catillon, Marie; Halavatyi, Aliaksandr; Medves, Sandrine; Van Troys, Marleen; Moes, Michèle; Baird, Michelle A; Davidson, Michael W; Schaffner-Reckinger, Elisabeth; Ampe, Christophe; Friederich, Evelyne

2015-01-01

Focal adhesions are integrin-based structures that link the actin cytoskeleton and the extracellular matrix. They play an important role in various cellular functions such as cell signaling, cell motility and cell shape. To ensure and fine tune these different cellular functions, adhesions are regulated by a large number of proteins. The LIM domain protein zyxin localizes to focal adhesions where it participates in the regulation of the actin cytoskeleton. Because of its interactions with a variety of binding partners, zyxin has been proposed to act as a molecular scaffold. Here, we studied the interaction of zyxin with such a partner: Tes. Similar to zyxin, Tes harbors three highly conserved LIM domains of which the LIM1 domain directly interacts with zyxin. Using different zyxin variants in pull-down assays and ectopic recruitment experiments, we identified the Tes binding site in zyxin and showed that four highly conserved amino acids are crucial for its interaction with Tes. Based upon these findings, we used a zyxin mutant defective in Tes-binding to assess the functional consequences of abrogating the zyxin-Tes interaction in focal adhesions. Performing fluorescence recovery after photobleaching, we showed that zyxin recruits Tes to focal adhesions and modulates its turnover in these structures. However, we also provide evidence for zyxin-independent localization of Tes to focal adhesions. Zyxin increases focal adhesion numbers and reduces focal adhesion lifetimes, but does so independent of Tes. Quantitative analysis showed that the loss of interaction between zyxin and Tes affects the process of cell spreading. We conclude that zyxin influences focal adhesion dynamics, that it recruits Tes and that this interaction is functional in regulating cell spreading.

Delineating the Tes Interaction Site in Zyxin and Studying Cellular Effects of Its Disruption

PubMed Central

Hadzic, Ermin; Catillon, Marie; Halavatyi, Aliaksandr; Medves, Sandrine; Van Troys, Marleen; Moes, Michèle; Baird, Michelle A.; Davidson, Michael W.; Schaffner-Reckinger, Elisabeth; Ampe, Christophe; Friederich, Evelyne

2015-01-01

Focal adhesions are integrin-based structures that link the actin cytoskeleton and the extracellular matrix. They play an important role in various cellular functions such as cell signaling, cell motility and cell shape. To ensure and fine tune these different cellular functions, adhesions are regulated by a large number of proteins. The LIM domain protein zyxin localizes to focal adhesions where it participates in the regulation of the actin cytoskeleton. Because of its interactions with a variety of binding partners, zyxin has been proposed to act as a molecular scaffold. Here, we studied the interaction of zyxin with such a partner: Tes. Similar to zyxin, Tes harbors three highly conserved LIM domains of which the LIM1 domain directly interacts with zyxin. Using different zyxin variants in pull-down assays and ectopic recruitment experiments, we identified the Tes binding site in zyxin and showed that four highly conserved amino acids are crucial for its interaction with Tes. Based upon these findings, we used a zyxin mutant defective in Tes-binding to assess the functional consequences of abrogating the zyxin-Tes interaction in focal adhesions. Performing fluorescence recovery after photobleaching, we showed that zyxin recruits Tes to focal adhesions and modulates its turnover in these structures. However, we also provide evidence for zyxin-independent localization of Tes to focal adhesions. Zyxin increases focal adhesion numbers and reduces focal adhesion lifetimes, but does so independent of Tes. Quantitative analysis showed that the loss of interaction between zyxin and Tes affects the process of cell spreading. We conclude that zyxin influences focal adhesion dynamics, that it recruits Tes and that this interaction is functional in regulating cell spreading. PMID:26509500

Listeria monocytogenes uses Listeria adhesion protein (LAP) to promote bacterial transepithelial translocation and induces expression of LAP receptor Hsp60.

PubMed

Burkholder, Kristin M; Bhunia, Arun K

2010-12-01

Listeria monocytogenes interaction with the intestinal epithelium is a key step in the infection process. We demonstrated that Listeria adhesion protein (LAP) promotes adhesion to intestinal epithelial cells and facilitates extraintestinal dissemination in vivo. The LAP receptor is a stress response protein, Hsp60, but the precise role for the LAP-Hsp60 interaction during Listeria infection is unknown. Here we investigated the influence of physiological stressors and Listeria infection on host Hsp60 expression and LAP-mediated bacterial adhesion, invasion, and transepithelial translocation in an enterocyte-like Caco-2 cell model. Stressors such as heat (41°C), tumor necrosis factor alpha (TNF-α) (100 U), and L. monocytogenes infection (10(4) to 10(6) CFU/ml) significantly (P < 0.05) increased plasma membrane and intracellular Hsp60 levels in Caco-2 cells and consequently enhanced LAP-mediated L. monocytogenes adhesion but not invasion of Caco-2 cells. In transepithelial translocation experiments, the wild type (WT) exhibited 2.7-fold more translocation through Caco-2 monolayers than a lap mutant, suggesting that LAP is involved in transepithelial translocation, potentially via a paracellular route. Short hairpin RNA (shRNA) suppression of Hsp60 in Caco-2 cells reduced WT adhesion and translocation 4.5- and 3-fold, respectively, while adhesion remained unchanged for the lap mutant. Conversely, overexpression of Hsp60 in Caco-2 cells enhanced WT adhesion and transepithelial translocation, but not those of the lap mutant. Furthermore, initial infection with a low dosage (10(6) CFU/ml) of L. monocytogenes increased plasma membrane and intracellular expression of Hsp60 significantly, which rendered Caco-2 cells more susceptible to subsequent LAP-mediated adhesion and translocation. These data provide insight into the role of LAP as a virulence factor during intestinal epithelial infection and pose new questions regarding the dynamics between the host stress response and pathogen infection.

ILK mediates LPS-induced vascular adhesion receptor expression and subsequent leucocyte trans-endothelial migration.

PubMed

Hortelano, Sonsoles; López-Fontal, Raquel; Través, Paqui G; Villa, Natividad; Grashoff, Carsten; Boscá, Lisardo; Luque, Alfonso

2010-05-01

The inflammatory response to injurious agents is tightly regulated to avoid adverse consequences of inappropriate leucocyte accumulation or failed resolution. Lipopolysaccharide (LPS)-activated endothelium recruits leucocytes to the inflamed tissue through controlled expression of membrane-associated adhesion molecules. LPS responses in macrophages are known to be regulated by integrin-linked kinase (ILK); in this study, we investigated the role of ILK in the regulation of the LPS-elicited inflammatory response in endothelium. This study was performed on immortalized mouse endothelial cells (EC) isolated from lung and coronary vasculature. Cells were thoroughly characterized and the role of ILK in the regulation of the LPS response was investigated by suppressing ILK expression using siRNA and shRNA technologies. Phenotypic and functional analyses confirmed that the immortalized cells behaved as true EC. LPS induced the expression of the inflammatory genes E-selectin, intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1). ILK knockdown impaired LPS-mediated endothelial activation by preventing the induction of ICAM-1 and VCAM-1. Blockade of the LPS-induced response inhibited the inflammatory-related processes of firm adhesion and trans-endothelial migration of leucocytes. ILK is involved in the expression of cell adhesion molecules by EC activated with the inflammatory stimulus LPS. This reduced expression modulates leucocyte adhesion to the endothelium and the extravasation process. This finding suggests ILK as a potential anti-inflammatory target for the development of vascular-specific treatments for inflammation-related diseases.

Public release of optimization of metallization scheme for thin emitter wrap-through solar cells for higher efficiency, reduced precious metal costs, and reduced stress.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ruby, Douglas Scott; Murphy, Brian; Meakin, David

2008-08-01

Back-contact crystalline-silicon photovoltaic solar cells and modules offer a number of advantages, including the elimination of grid shadowing losses, reduced cost through use of thinner silicon substrates, simpler module assembly, and improved aesthetics. While the existing edge tab method for interconnecting and stringing edge-connected back contact cells is acceptably straightforward and reliable, there are further gains to be exploited when you have both contact polarities on one side of the cell. In this work, we produce 'busbarless' emitter wrap-through solar cells that use 41% of the gridline silver (Ag) metallization mass compared to the edge tab design. Further, series resistancemore » power losses are reduced by extraction of current from more places on the cell rear, leading to a fill factor improvement of about 6% (relative) on the module level. Series resistance and current-generation losses associated with large rear bondpads and busbars are eliminated. Use of thin silicon (Si) wafers is enabled because of the reduced Ag metallization mass and by interconnection with conductive adhesives leading to reduced bow. The busbarless cell design interconnected with conductive adhesives passes typical International Electrotechnical Commission damp heat and thermal cycling test.« less

RNAi knockdown of the focal adhesion protein TES reveals its role in actin stress fibre organisation.

PubMed

Griffith, Elen; Coutts, Amanda S; Black, Donald M

2005-03-01

TES was originally identified as a candidate tumour suppressor gene and has subsequently been found to encode a novel focal adhesion protein. As well as localising to cell-matrix adhesions, TES localises to cell-cell contacts and to actin stress fibres. TES interacts with a variety of cytoskeletal proteins including zyxin, mena, VASP, talin and actin. There is evidence that TES may function in actin-dependent processes as overexpression of TES results in increased cell spreading and decreased cell motility. Together with TES's interacting partners, these data suggest that TES might be involved in regulation of the actin cytoskeleton. Here, for the first time, we have used RNAi to successfully knockdown TES in HeLa cells and we demonstrate that loss of TES from focal adhesions results in loss of actin stress fibres. Similarly, and as previously reported, RNAi-mediated knockdown of zyxin results in loss of actin stress fibres. TES siRNA treated cells show reduced RhoA activity, suggesting that the Rho GTPase pathway may be involved in the TES RNAi-induced loss of stress fibres. We have also used RNAi to examine the requirement of TES and zyxin for each other's localisation at focal adhesions, and we propose a hierarchy of recruitment, with zyxin being first, followed by VASP and then TES. Cell Motil. Copyright 2005 Wiley-Liss, Inc.

Efficacy of surface-generated nitric oxide against Candida albicans adhesion and biofilm formation.

PubMed

Privett, Benjamin J; Nutz, Steven T; Schoenfisch, Mark H

2010-11-01

This report details the efficacy of nitric oxide (NO)-releasing xerogel surfaces composed of N-(6-aminohexyl)aminopropyl trimethoxysilane (AHAP3) and isobutyltrimethoxysilane (BTMOS) against Candida albicans adhesion, viability, and biofilm formation. A parallel plate flow cell assay was used to examine the effect of NO on planktonic fungal cells. Nitric oxide fluxes as low as 14 pmol cm(-2) s(-1) were sufficient to reduce fungal adhesion by ∼49% over the controls after 90 min. By utilizing a fluorescence live/dead assay and replicate plating, NO flux was determined to reduce fungal viability in a dose-dependent manner. The formation of C. albicans biofilms on NO-releasing xerogel-coated silicon rubber (SiR) coupons was impeded when compared to control (non-NO-releasing) and bare SiR surfaces. The synergistic efficacy of NO and silver sulfadiazine against adhered fungal cells and biofilms is reported with increased killing and biofilm inhibition over NO alone.

Paeonia lactiflora Enhances the Adhesion of Trophoblast to the Endometrium via Induction of Leukemia Inhibitory Factor Expression

PubMed Central

Park, Mi-Ju; Lee, Kyu Sup; Yoon, Youngjin; Kim, Hyung Sik; Lee, Jun Hee; Kwon, Sang-Mo; Lee, Syng-Ook; Kim, Keuk-Jun; Baek, Jin-Ho; Ha, Ki-Tae

2016-01-01

In the present study, we investigated the role of Paeonia lactiflora Pall. extract on embryo implantation in vitro and in vivo. A polysaccharides depleted-water extract of P. lactiflora (PL-PP) increased LIF expression in human endometrial Ishikawa cells at non-cytotoxic doses. PL-PP significantly increased the adhesion of the human trophectoderm-derived JAr spheroids to endometrial Ishikawa cells. PL-PP-induced LIF expression was decreased in the presence of a p38 kinase inhibitor SB203580 and an MEK/ERK inhibitor U0126. Furthermore, endometrial LIF knockdown by shRNA reduced the expression of integrins β3 and β5 and adhesion of JAr spheroids to Ishikawa cells. In vivo administration of PL-PP restored the implantation of mouse blastocysts in a mifepristone-induced implantation failure mice model. Our results demonstrate that PL-PP increases LIF expression via the p38 and MEK/ERK pathways and favors trophoblast adhesion to endometrial cells. PMID:26839969

Lateral adhesion drives reintegration of misplaced cells into epithelial monolayers.

PubMed

Bergstralh, Dan T; Lovegrove, Holly E; St Johnston, Daniel

2015-11-01

Cells in simple epithelia orient their mitotic spindles in the plane of the epithelium so that both daughter cells are born within the epithelial sheet. This is assumed to be important to maintain epithelial integrity and prevent hyperplasia, because misaligned divisions give rise to cells outside the epithelium. Here we test this assumption in three types of Drosophila epithelium; the cuboidal follicle epithelium, the columnar early embryonic ectoderm, and the pseudostratified neuroepithelium. Ectopic expression of Inscuteable in these tissues reorients mitotic spindles, resulting in one daughter cell being born outside the epithelial layer. Live imaging reveals that these misplaced cells reintegrate into the tissue. Reducing the levels of the lateral homophilic adhesion molecules Neuroglian or Fasciclin 2 disrupts reintegration, giving rise to extra-epithelial cells, whereas disruption of adherens junctions has no effect. Thus, the reinsertion of misplaced cells seems to be driven by lateral adhesion, which pulls cells born outside the epithelial layer back into it. Our findings reveal a robust mechanism that protects epithelia against the consequences of misoriented divisions.

Effect of p120 catenin silencing on biological behaviors of PANC-1 cells.

PubMed

Cheng, Zhangjun; Assfag, Volker; Shi, Xin; Lin, Shibo; Xia, Jiangyan; Yang, Pinghua; Hüser, Norbert; Shen, Feng

2012-10-01

This study examined the possible role of p120ctn in the pathogenesis and development of pancreatic cancer. PANC-1 cells, a kind of human pancreatic carcinoma cell line, were cultured in this study. p120ctn was immunocytochemically detected in PANC-1 cells. The recombinant lentivirus vector was constructed to knock down the p120ctn expression of PANC-1 cells. Real-time quantitative PCR (RQ-PCR) and Western blotting were used to determine the expression of p120ctn and E-cadherin in PANC-1 cells after p120ctn knockdown. The adhesion, invasion and migration capacity of PANC-1 cells after p120ctn knockdown was detected by cell adhesion, invasion and migration assays. Cell growth was measured by the MTT method. Cell cycle and apoptosis were analyzed by fluorescence-activated cell sorting. The results showed that p120ctn knockdown led to significantly down-regulated E-cadherin and a reduced cell-to-cell adhesion ability in PANC-1 cells. shRNA-mediated knockdown of p120ctn reduced invasion and migration capacity of PANC-1 cells, inhibited cell growth, caused a significant decrease in the percentage of cells in G(1), an increase in S, and promoted apoptosis of PANC-1 cells. It was concluded that p120ctn plays a pivotal role in the proliferation and metastasis of pancreatic carcinoma, suggesting that p120ctn is a novel target for pancreatic carcinoma treatment.

Anti-LRP/LR Specific Antibody IgG1-iS18 Impedes Adhesion and Invasion of Liver Cancer Cells

PubMed Central

Chetty, Carryn; Khumalo, Thandokuhle; Da Costa Dias, Bianca; Reusch, Uwe; Knackmuss, Stefan; Little, Melvyn; Weiss, Stefan F. T.

2014-01-01

Two key events, namely adhesion and invasion, are pivotal to the occurrence of metastasis. Importantly, the 37 kDa/67 kDa laminin receptor (LRP/LR) has been implicated in enhancing these two events thus facilitating cancer progression. In the current study, the role of LRP/LR in the adhesion and invasion of liver cancer (HUH-7) and leukaemia (K562) cells was investigated. Flow cytometry revealed that the HUH-7 cells displayed significantly higher cell surface LRP/LR levels compared to the poorly-invasive breast cancer (MCF-7) control cells, whilst the K562 cells displayed significantly lower cell surface LRP/LR levels in comparison to the MCF-7 control cells. However, Western blotting and densitometric analysis revealed that all three tumorigenic cell lines did not differ significantly with regards to total LRP/LR levels. Furthermore, treatment of liver cancer cells with anti-LRP/LR specific antibody IgG1-iS18 (0.2 mg/ml) significantly reduced the adhesive potential of cells to laminin-1 and the invasive potential of cells through the ECM-like Matrigel, whilst leukaemia cells showed no significant differences in both instances. Additionally, Pearson's correlation coefficients suggested direct proportionality between cell surface LRP/LR levels and the adhesive and invasive potential of liver cancer and leukaemia cells. These findings suggest the potential use of anti-LRP/LR specific antibody IgG1-iS18 as an alternative therapeutic tool for metastatic liver cancer through impediment of the LRP/LR- laminin-1 interaction. PMID:24798101

Reprogramming of the Ovarian Tumor Stroma by Activation of a Biomechanical ECM Switch

DTIC Science & Technology

2016-09-01

Denatured collagen was detec- ted with anticollagen antibody (1:1000). For integrin-blocking enzyme -linked immunosorbent assay, wells were coated with...migration on denatured collagen; it failed to reduce cell adhesion. Moreover a peptide antagonist of alpha 10 beta 1 may inhibit ovarian tumor growth in...stromal cell adhesion, migration and proliferation on distinct ECM substrates including native and denatured collagen. 4   D). As outlined in aim 2

Magnolol attenuates VCAM-1 expression in vitro in TNF-α-treated human aortic endothelial cells and in vivo in the aorta of cholesterol-fed rabbits

PubMed Central

Chen, Yung-Hsiang; Lin, Shing-Jong; Chen, Jaw-Wen; Ku, Hung-Hai; Chen, Yuh-Lien

2002-01-01

In a previous study, we showed that magnolol, a potent antioxidant derived from a Chinese herb, attenuates monocyte chemotactic protein-1 (MCP-1) expression and intimal hyperplasia in the balloon-injured aorta of cholesterol-fed rabbits. Expression of cell adhesion molecules by the arterial endothelium and the attachment of leukocytes to the endothelium may play a major role in atherosclerosis. In the present study, the effects of magnolol on the expression of endothelial-leukocyte adhesion molecules and the activation of nuclear factor kappa B (NF-κB) in tumour necrosis factor-α (TNF-α)-treated human aortic endothelial cells (HAECs) were investigated.Pretreatment of HAECs with magnolol (5 μM) significantly suppressed the TNF-α-induced expression of vascular cell adhesion molecule-1 (VCAM-1) (64.8±1.9%), but had no effect on the expression of intercellular cell adhesion molecule-1 and endothelial cell selectin.Magnolol (5 and 10 μM) significantly reduced the binding of the human monocytic cell line, U937, to TNF-α-stimulated HAECs (58.4 and 56.4% inhibition, respectively). Gel shift assays using the 32P-labelled NF-κB consensus sequence as probe showed that magnolol pretreatment reduced the density of the shifted bands seen after TNF-α-induced activation. Immunoblot analysis and immunofluorescence staining of nuclear extracts demonstrated a 58% reduction in the amount of NF-κB p65 in the nuclei in magnolol-treated HAECs. Magnolol also attenuated intracellular H2O2 generation in both control and TNF-α treated HAECs.Furthermore, in vivo, magnolol attenuates the intimal thickening and TNF-α and VCAM-1 protein expression seen in the thoracic aortas of cholesterol-fed rabbits.Taken together, these data demonstrate that magnolol inhibits TNF-α-induced nuclear translocation of NF-κB p65 and thereby suppresses expression of VCAM-1, resulting in reduced adhesion of leukocytes. These results suggest that magnolol has anti-inflammatory properties and may play important roles in the prevention of atherosclerosis and inflammatory responses in vivo. PMID:11786478

Ovarian carcinoma ascites spheroids adhere to extracellular matrix components and mesothelial cell monolayers.

PubMed

Burleson, Kathryn M; Casey, Rachael C; Skubitz, Keith M; Pambuccian, Stephan E; Oegema, Theodore R; Skubitz, Amy P N

2004-04-01

Ovarian carcinoma cells form multicellular aggregates, or spheroids, in the peritoneal cavity of patients with advanced disease. The current paradigm that ascites spheroids are non-adhesive leaves their contribution to ovarian carcinoma dissemination undefined. Here, spheroids obtained from ovarian carcinoma patients' ascites were characterized for their ability to adhere to molecules encountered in the peritoneal cavity, with the goal of establishing their potential to contribute to ovarian cancer spread. Spheroids were recovered from the ascites fluid of 11 patients with stage III or stage IV ovarian carcinoma. Adhesion assays to extracellular matrix (ECM) proteins and human mesothelial cell monolayers were performed for each of the ascites spheroid samples. Subsequently, inhibition assays were performed to identify the cell receptors involved. Most ascites samples adhered moderately to fibronectin and type I collagen, with reduced adhesion to type IV collagen and laminin. Monoclonal antibodies against the beta1 integrin subunit partially inhibited this adhesion. Ascites spheroids also adhered to hyaluronan. Additionally, spheroids adhered to live, but not fixed, human mesothelial cell monolayers, and this adhesion was partially mediated by beta1 integrins. The cellular content of the ascites fluid has often been considered non-adhesive, but our findings are the first to suggest that patient-derived ascites spheroids can adhere to mesothelial extracellular matrix via beta1 integrins, indicating that spheroids should not be ignored in the dissemination of ovarian cancer.

Cell adhesion during bullet motion in capillaries.

PubMed

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

2016-08-01

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

L-asparaginase inhibits invasive and angiogenic activity and induces autophagy in ovarian cancer

PubMed Central

Yu, Minshu; Henning, Ryan; Walker, Amanda; Kim, Geoffrey; Perroy, Alyssa; Alessandro, Riccardo; Virador, Victoria; Kohn, Elise C

2012-01-01

Recent work identified L-asparaginase (L-ASP) as a putative therapeutic target for ovarian cancer. We suggest that L-ASP, a dysregulator of glycosylation, would interrupt the local microenvironment, affecting the ovarian cancer cell—endothelial cell interaction and thus angiogenesis without cytotoxic effects. Ovarian cancer cell lines and human microvascular endothelial cells (HMVEC) were exposed to L-ASP at physiologically attainable concentrations and subjected to analyses of endothelial tube formation, invasion, adhesion and the assessment of sialylated proteins involved in matrix-associated and heterotypic cell adhesion. Marked reduction in HMVEC tube formation in vitro, HMVEC and ovarian cancer cell invasion, and heterotypic cell-cell and cell-matrix adhesion was observed (P < 0.05–0.0001). These effects were associated with reduced binding to ß1integrin, activation of FAK, and cell surface sialyl LewisX (sLex) expression. No reduction in HMVEC E-selectin expression was seen consistent with the unidirectional inhibitory actions observed. L-ASP concentrations were non-toxic to either ovarian cancer or HMVEC lines in the time frame of the assays. However, early changes of autophagy were observed in both cell types with induction of ATG12, beclin-1, and cleavage of LC-3, indicating cell injury did occur. These data and the known mechanism of action of L-ASP on glycosylation of nascent proteins suggest that L-ASP reduces of ovarian cancer dissemination and progression through modification of its microenvironment. The reduction of ovarian cancer cell surface sLex inhibits interaction with HMVEC and thus HMVEC differentiation into tubes, inhibits interaction with the local matrix reducing invasive behaviour, and causes cell injury initiating autophagy in tumour and vascular cells. PMID:22333033

Biocompatibility and bond degradation of poly-acrylic acid coated copper iodide-adhesives.

PubMed

ALGhanem, Adi; Fernandes, Gabriela; Visser, Michelle; Dziak, Rosemary; Renné, Walter G; Sabatini, Camila

2017-09-01

To investigate the effect of poly-acrylic acid (PAA) copper iodide (CuI) adhesives on bond degradation, tensile strength, and biocompatibility. PAA-CuI particles were incorporated into Optibond XTR, Optibond Solo and XP Bond in 0.1 and 0.5mg/ml. Clearfil SE Protect, an MDPB-containing adhesive, was used as control. The adhesives were applied to human dentin, polymerized and restored with composite in 2mm-increments. Resin-dentin beams (0.9±0.1mm 2 ) were evaluated for micro-tensile bond strength after 24h, 6 months and 1year. Hourglass specimens (10×2×1mm) were evaluated for ultimate tensile strength (UTS). Cell metabolic function of human gingival fibroblast cells exposed to adhesive discs (8×1mm) was assessed with MTT assay. Copper release from adhesive discs (5×1mm) was evaluated with UV-vis spectrophotometer after immersion in 0.9% NaCl for 1, 3, 5, 7, 10, 14, 21 and 30 days. SEM, EDX and XRF were conducted for microstructure characterization. XTR and Solo did not show degradation when modified with PAA-CuI regardless of the concentration. The UTS for adhesives containing PAA-CuI remained unaltered relative to the controls. The percent viable cells were reduced for Solo 0.5mg/ml and XP 0.1 or 0.5mg/ml PAA-CuI. XP demonstrated the highest ion release. For all groups, the highest release was observed at days 1 and 14. PAA-CuI particles prevented the bond degradation of XTR and Solo after 1year without an effect on the UTS for any adhesive. Cell viability was affected for some adhesives. A similar pattern of copper release was demonstrated for all adhesives. Copyright © 2017. Published by Elsevier Ltd.

[Regulative effects of hydrogen-rich medium on monocytic adhesion and vascular endothelial permeability].

PubMed

Wang, Wei-na; Xie, Ke-liang; Chen, Hong-guang; Han, Huan-zhi; Wang, Guo-lin; Yu, Yong-hao

2013-11-19

To explore the regulative effects of hydrogen-rich medium on lipopolysaccharide (LPS)-induced monocytes adhesion to human umbilical vein endothelial cells (HUVEC) and vascular endothelial permeability in vitro. Endothelial cells were seeded in 6-well plates and randomly divided into 4 groups (n = 42 each):control (A), hydrogen-rich medium (B), LPS (C) and LPS+hydrogen-rich medium (D). Cells were cultured in plain culture medium in groups A and C or in hydrogen-saturated culture medium in groups B and D.LPS 1 µg/ml was added into groups C and D.When forming a monolayer, monocytes were added into each group after 6, 12 and 24 h respectively. After a 90-minute co-culturing, adhesion status was detected by Wright-Giemsa stain.Supernatants were collected to detect the concentrations of vascular cell adhesion molecule-1 (VCAM-1) and E-selectin by enzyme-linked immunosorbent assay (ELISA). The expression of VE-cadherin was measured by Western blot. Cells were stained with immunofluorescence to show the distribution of VE-cadherin after a 24-hour incubation. Compared with group A, the adhesion of monocytes to endothelial cells increased (P < 0.05) in group C, the levels of E-selectin and VCAM-1 became elevated (P < 0.05) while the expression of VE-cadherin decreased significantly (P < 0.05). Compared with group C, adhesion decreased in group D (P < 0.05), the levels of E-selectin and VCAM-1 decreased (P < 0.05) while there was an increased expression of VE-cadherin (P < 0.05). Three timepoints showed the same tendency. The results of 24 h fluorescence indicated that, compared with group A, VE-cadherin was incomplete in cell-cell connections in group C.However it was complete and well-distributed in group D versus group C. Hydrogen-rich medium may reduce the LPS-induced release of adhesion molecules, lessen monocytic adhesion to HUVEC and regulate the expression of VE-cadherin to protect vascular permeability.

Magnolol Inhibits Human Glioblastoma Cell Migration by Regulating N-Cadherin.

PubMed

Cheng, Yu-Chen; Tsao, Min-Jen; Chiu, Chen-Yang; Kan, Po-Chieh; Chen, Ying

2018-06-01

Glioblastoma is a primary malignant brain tumor with a poor prognosis. An effective treatment for glioblastoma is needed. Magnolol is a natural compound from Magnolia officinalis suggested to have antiproliferative activity. The aim of this research was to investigate the anticancer effects of magnolol in glioma, with an emphasis on migration and the underlying mechanism. Magnolol decreased the expression of focal adhesion-related proteins and inhibited LN229 and U87MG glioma cell migration. The levels of phosphorylated myosin light chain (p-MLC), phosphorylated myosin light chain kinase and myosin phosphatase target subunit 1 were reduced in response to magnolol treatment. In addition, immunostaining and membrane fractionation showed that the distribution of N-cadherin at the glioma cell membrane was decreased by magnolol. In an orthotropic xenograft animal model, magnolol treatment not only inhibited tumor progression but also reduced p-MLC and N-cadherin protein expression. In conclusion, magnolol reduces cell migration, potentially through regulating focal adhesions and N-cadherin in glioma cells. Magnolol is a potential candidate for glioma treatment.

The effects of nanophase ceramic materials on select functions of human mesenchymal stem cells

NASA Astrophysics Data System (ADS)

Dulgar-Tulloch, Aaron Joseph

2005-11-01

Modification of the chemistry and surface topography of nanophase ceramics can provide biomaterial formulations capable of directing the functions of adherent cells. This effect relies on the type, amount, and conformation of adsorbed proteins that mediate the adhesion of mesenchymally-descended lineages. The mechanisms driving this response are not yet well-understood and have not been investigated for human mesenchymal stem cells (HMSCs), a progenitor-lineage critical to orthopaedic biomaterials. The present study addressed these needs by examining the in vitro adhesion, proliferation, and osteogenic differentiation of HMSCs as a function of substrate chemistry and grain size, with particular attention to the protein-mediated mechanisms of cell adhesion. Alumina, titania, and hydroxyapatite substrates were prepared with 1500, 200, 50, and 24 (alumina only) nm grain sizes, and characterized with respect to surface properties, porosity, composition, and phase. Adhesion of HMSCs was dependent upon both chemistry and grain size. Specifically, adhesion on alumina and hydroxyapatite was reduced on 50 and 24 (alumina only) nm surfaces, as compared to 1500 and 200 nm surfaces, while adhesion on titania substrates was independent of grain size. Investigation into the protein-mediated mechanisms of this response identified vitronectin as the dominant adhesive protein, demonstrated random protein distribution across the substrate surface without aggregation or segregation, and confirmed the importance of the type, amount, and conformation of adsorbed proteins in cell adhesion. Minimal cell proliferation was observed on 50 and 24 (alumina only) nm substrates of any chemistry. Furthermore, cell proliferation was up-regulated on 200 nm substrates after 7 days of culture. Osteogenic differentiation was not detected on 50 nm substrates throughout the 28 day culture period. In contrast, osteogenic differentiation was strongly enhanced on 200 nm substrates, occurring approximately 7 days earlier and in greater magnitude than that observed on 1500 nm substrates. In summary, the current study elucidated the chemical and topographical cues necessary to optimize the vitronectin-mediated adhesion, proliferation, and differentiation of human mesenchymal stem cells on ceramic surfaces. These results expand the understanding of surface-mediated cell functions and provide information pertinent to the design of next-generation orthopaedic and tissue engineering biomaterials.

Impacts of icodextrin on integrin-mediated wound healing of peritoneal mesothelial cells.

PubMed

Matsumoto, Mika; Tamura, Masahito; Miyamoto, Tetsu; Furuno, Yumi; Kabashima, Narutoshi; Serino, Ryota; Shibata, Tatsuya; Kanegae, Kaori; Takeuchi, Masaaki; Abe, Haruhiko; Okazaki, Masahiro; Otsuji, Yutaka

2012-06-14

Exposure to glucose and its metabolites in peritoneal dialysis fluid (PDF) results in structural alterations of the peritoneal membrane. Icodextrin-containing PDF eliminates glucose and reduces deterioration of peritoneal membrane function, but direct effects of icodextrin molecules on peritoneal mesothelial cells have yet to be elucidated. We compared the impacts of icodextrin itself with those of glucose under PDF-free conditions on wound healing processes of injured mesothelial cell monolayers, focusing on integrin-mediated cell adhesion mechanisms. Regeneration processes of the peritoneal mesothelial cell monolayer were investigated employing an in vitro wound healing assay of cultured rat peritoneal mesothelial cells treated with icodextrin powder- or glucose-dissolved culture medium without PDF, as well as icodextrin- or glucose-containing PDF. The effects of icodextrin on integrin-mediated cell adhesions were examined by immunocytochemistry and Western blotting against focal adhesion kinase (FAK). Cell migration over fibronectin was inhibited in conventional glucose-containing PDF, while icodextrin-containing PDF exerted no significant inhibitory effects. Culture medium containing 1.5% glucose without PDF also inhibited wound healing of mesothelial cells, while 7.5% icodextrin-dissolved culture medium without PDF had no inhibitory effects. Glucose suppressed cell motility by inhibiting tyrosine phosphorylation of FAK, formation of focal adhesions, and cell spreading, while icodextrin had no effects on any of these mesothelial cell functions. Our results demonstrate icodextrin to have no adverse effects on wound healing processes of peritoneal mesothelial cells. Preservation of integrin-mediated cell adhesion might be one of the molecular mechanisms accounting for the superior biocompatibility of icodextrin-containing PDF. Copyright © 2012 Elsevier Inc. All rights reserved.

High aspect ratio silicon nanowires control fibroblast adhesion and cytoskeleton organization

NASA Astrophysics Data System (ADS)

Andolfi, Laura; Murello, Anna; Cassese, Damiano; Ban, Jelena; Dal Zilio, Simone; Lazzarino, Marco

2017-04-01

Cell-cell and cell-matrix interactions are essential to the survival and proliferation of most cells, and are responsible for triggering a wide range of biochemical pathways. More recently, the biomechanical role of those interactions was highlighted, showing, for instance, that adhesion forces are essential for cytoskeleton organization. Silicon nanowires (Si NWs) with their small size, high aspect ratio and anisotropic mechanical response represent a useful model to investigate the forces involved in the adhesion processes and their role in cellular development. In this work we explored and quantified, by single cell force spectroscopy (SCFS), the interaction of mouse embryonic fibroblasts with a flexible forest of Si NWs. We observed that the cell adhesion forces are comparable to those found on collagen and bare glass coverslip, analogously the membrane tether extraction forces are similar to that on collagen but stronger than that on bare flat glass. Cell survival did not depend significantly on the substrate, although a reduced proliferation after 36 h was observed. On the contrary both cell morphology and cytoskeleton organization revealed striking differences. The cell morphology on Si-NW was characterized by a large number of filopodia and a significant decrease of the cell mobility. The cytoskeleton organization was characterized by the absence of actin fibers, which were instead dominant on collagen and flat glass support. Such findings suggest that the mechanical properties of disordered Si NWs, and in particular their strong asymmetry, play a major role in the adhesion, morphology and cytoskeleton organization processes. Indeed, while adhesion measurements by SCFS provide out-of-plane forces values consistent with those measured on conventional substrates, weaker in-plane forces hinder proper cytoskeleton organization and migration processes.

High aspect ratio silicon nanowires control fibroblast adhesion and cytoskeleton organization.

PubMed

Andolfi, Laura; Murello, Anna; Cassese, Damiano; Ban, Jelena; Dal Zilio, Simone; Lazzarino, Marco

2017-04-18

Cell-cell and cell-matrix interactions are essential to the survival and proliferation of most cells, and are responsible for triggering a wide range of biochemical pathways. More recently, the biomechanical role of those interactions was highlighted, showing, for instance, that adhesion forces are essential for cytoskeleton organization. Silicon nanowires (Si NWs) with their small size, high aspect ratio and anisotropic mechanical response represent a useful model to investigate the forces involved in the adhesion processes and their role in cellular development. In this work we explored and quantified, by single cell force spectroscopy (SCFS), the interaction of mouse embryonic fibroblasts with a flexible forest of Si NWs. We observed that the cell adhesion forces are comparable to those found on collagen and bare glass coverslip, analogously the membrane tether extraction forces are similar to that on collagen but stronger than that on bare flat glass. Cell survival did not depend significantly on the substrate, although a reduced proliferation after 36 h was observed. On the contrary both cell morphology and cytoskeleton organization revealed striking differences. The cell morphology on Si-NW was characterized by a large number of filopodia and a significant decrease of the cell mobility. The cytoskeleton organization was characterized by the absence of actin fibers, which were instead dominant on collagen and flat glass support. Such findings suggest that the mechanical properties of disordered Si NWs, and in particular their strong asymmetry, play a major role in the adhesion, morphology and cytoskeleton organization processes. Indeed, while adhesion measurements by SCFS provide out-of-plane forces values consistent with those measured on conventional substrates, weaker in-plane forces hinder proper cytoskeleton organization and migration processes.

Cytotoxic effects of resin-modified orthodontic band adhesives. Are they safe?

PubMed

Malkoc, Siddik; Corekci, Bayram; Botsali, Hayriye Esra; Yalçin, Muhammet; Sengun, Abdülkadir

2010-09-01

To evaluate the cytotoxic effects of three different resin-modified orthodontic band adhesives. Three resin-modified orthodontic band adhesives (Bisco Ortho Band Paste LC, Multi-Cure Glass Ionomer Band Cement, and Transbond Plus Light Cure Band Adhesive) were prepared and the samples were extracted in 3 mL of Basal Medium Eagle with 10% newborn calf serum for 24 hours. The L929 cells were plated (25,000 cells/mL) in wells of 96-well dishes and maintained in a humidified incubator for 24 hours at 37 degrees C, 5% CO(2), and 95% air. After 24-hour incubation of the cells, the incubation medium was replaced by the immersed medium in which the samples were stored. Then L929 cells were incubated in contact with eluates for 24 hours. The cell mitochondrial activity was evaluated by the methyltetrazolium test. Twelve wells were used for each specimen, and methyltetrazolium tests were applied two times. The data were statistically analyzed using one-way analysis of variance and Tukey Honestly Significantly Different tests. Results with L929 fibroblasts demonstrated that all freshly prepared resin-modified orthodontic band adhesive materials reduced vital cell numbers (P > .05), in comparison to the control group. Our data demonstrate that all materials showed significant cytotoxicity compared to the control group. The results indicate that all materials showed significant cytotoxicity compared to the control group, and further studies using different test methods are needed for all resin-modified orthodontic band adhesives.

Cell/surface interactions on laser micro-textured titanium-coated silicon surfaces.

PubMed

Mwenifumbo, Steven; Li, Mingwei; Chen, Jianbo; Beye, Aboubaker; Soboyejo, Wolé

2007-01-01

This paper examines the effects of nano-scale titanium coatings, and micro-groove/micro-grid patterns on cell/surface interactions on silicon surfaces. The nature of the cellular attachment and adhesion to the coated/uncoated micro-textured surfaces was elucidated by the visualization of the cells and relevant cytoskeletal & focal adhesion proteins through scanning electron microscopy and immunofluorescence staining. Increased cell spreading and proliferation rates are observed on surfaces with 50 nm thick Ti coatings. The micro-groove geometries have been shown to promote contact guidance, which leads to reduced scar tissue formation. In contrast, smooth surfaces result in random cell orientations and the increased possibility of scar tissue formation. Immunofluorescence cell staining experiments also reveal that the actin stress fibers are aligned along the groove dimensions, with discrete focal adhesions occurring along the ridges, within the grooves and at the ends of the cell extensions. The implications of the observed cell/surface interactions are discussed for possible applications of silicon in implantable biomedical systems.

Sulforaphane reduces vascular inflammation in mice and prevents TNF-α-induced monocyte adhesion to primary endothelial cells through interfering with the NF-κB pathway.

PubMed

Nallasamy, Palanisamy; Si, Hongwei; Babu, Pon Velayutham Anandh; Pan, Dengke; Fu, Yu; Brooke, Elizabeth A S; Shah, Halley; Zhen, Wei; Zhu, Hong; Liu, Dongmin; Li, Yunbo; Jia, Zhenquan

2014-08-01

Sulforaphane, a naturally occurring isothiocyanate present in cruciferous vegetables, has received wide attention for its potential to improve vascular function in vitro. However, its effect in vivo and the molecular mechanism of sulforaphane at physiological concentrations remain unclear. Here, we report that a sulforaphane concentration as low as 0.5 μM significantly inhibited tumor necrosis factor-α (TNF-α)-induced adhesion of monocytes to human umbilical vein endothelial cells, a key event in the pathogenesis of atherosclerosis both in static and under flow conditions. Such physiological concentrations of sulforaphane also significantly suppressed TNF-α-induced production of monocyte chemotactic protein-1 and adhesion molecules including soluble vascular adhesion molecule-1 and soluble E-selectin, key mediators in the regulation of enhanced endothelial cell-monocyte interaction. Furthermore, sulforaphane inhibited TNF-α-induced nuclear factor (NF)-κB transcriptional activity, Inhibitor of NF-κB alpha (IκBα) degradation and subsequent NF-κB p65 nuclear translocation in endothelial cells, suggesting that sulforaphane can inhibit inflammation by suppressing NF-κB signaling. In an animal study, sulforaphane (300 ppm) in a mouse diet significantly abolished TNF-α-increased ex vivo monocyte adhesion and circulating adhesion molecules and chemokines in C57BL/6 mice. Histology showed that sulforaphane treatment significantly prevented the eruption of endothelial lining in the intima layer of the aorta and preserved elastin fibers' delicate organization, as shown by Verhoeff-van Gieson staining. Immunohistochemistry studies showed that sulforaphane treatment also reduced vascular adhesion molecule-1 and monocyte-derived F4/80-positive macrophages in the aorta of TNF-α-treated mice. In conclusion, sulforaphane at physiological concentrations protects against TNF-α-induced vascular endothelial inflammation, in both in vitro and in vivo models. This anti-inflammatory effect of sulforaphane may be, at least in part, associated with interfering with the NF-κB pathway. Copyright © 2014 Elsevier Inc. All rights reserved.

Using RNA interference to knock down the adhesion protein TES.

PubMed

Griffith, Elen

2007-01-01

RNA interference (RNAi) is a specific and efficient method to knock down protein levels using small interfering RNAs (siRNAs), which target mRNA degradation. RNAi can be used in mammalian cell culture systems to target any protein of interest, and several studies have used this method to knock down adhesion proteins. We used siRNAs to knock down the levels of TES, a focal adhesion protein, in HeLa cells. We demonstrated knockdown of both TES mRNA and TES protein. Although total knockdown of TES was not achieved, the observed reduction in TES protein was sufficient to result in a cellular phenotype of reduced actin stress fibers.

Streptococcus pyogenes CAMP factor promotes bacterial adhesion and invasion in pharyngeal epithelial cells without serum via PI3K/Akt signaling pathway.

PubMed

Kurosawa, Mie; Oda, Masataka; Domon, Hisanori; Isono, Toshihito; Nakamura, Yuki; Saitoh, Issei; Hayasaki, Haruaki; Yamaguchi, Masaya; Kawabata, Shigetada; Terao, Yutaka

2018-01-01

Streptococcus pyogenes is a bacterium that causes systemic diseases, such as pharyngitis and toxic shock syndrome, via oral- or nasal-cavity infection. S. pyogenes produces various molecules known to function with serum components that lead to bacterial adhesion and invasion in human tissues. In this study, we identified a novel S. pyogenes adhesin/invasin. Our results revealed that CAMP factor promoted streptococcal adhesion and invasion in pharyngeal epithelial Detroit562 cells without serum. Recombinant CAMP factor initially localized on the membranes of cells and then became internalized in the cytosol following S. pyogenes infection. Additionally, CAMP factor phosphorylated phosphoinositide 3-kinase and serine-threonine kinase in the cells. ELISA results demonstrate that CAMP factor affected the amount of phosphorylated phosphoinositide 3-kinase and serine-threonine kinase in Detroit562 cells. Furthermore, CAMP factor did not reverse the effect of phosphoinositide 3-kinase knockdown by small interfering RNA in reducing the level of adhesion and invasion of S. pyogenes isogenic cfa-deficient mutant. These results suggested that S. pyogenes CAMP factor activated the phosphoinositide 3-kinase/serine-threonine kinase signaling pathway, promoting S. pyogenes invasion of Detroit562 cells without serum. Our findings suggested that CAMP factor played an important role on adhesion and invasion in pharyngeal epithelial cells. Copyright © 2017 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Osthole Suppresses the Migratory Ability of Human Glioblastoma Multiforme Cells via Inhibition of Focal Adhesion Kinase-Mediated Matrix Metalloproteinase-13 Expression

PubMed Central

Tsai, Cheng-Fang; Yeh, Wei-Lan; Chen, Jia-Hong; Lin, Chingju; Huang, Shiang-Suo; Lu, Dah-Yuu

2014-01-01

Glioblastoma multiforme (GBM) is the most common type of primary and malignant tumor occurring in the adult central nervous system. GBM often invades surrounding regions of the brain during its early stages, making successful treatment difficult. Osthole, an active constituent isolated from the dried C. monnieri fruit, has been shown to suppress tumor migration and invasion. However, the effects of osthole in human GBM are largely unknown. Focal adhesion kinase (FAK) is important for the metastasis of cancer cells. Results from this study show that osthole can not only induce cell death but also inhibit phosphorylation of FAK in human GBM cells. Results from this study show that incubating GBM cells with osthole reduces matrix metalloproteinase (MMP)-13 expression and cell motility, as assessed by cell transwell and wound healing assays. This study also provides evidence supporting the potential of osthole in reducing FAK activation, MMP-13 expression, and cell motility in human GBM cells. PMID:24599080

Redox sensor CtBP mediates hypoxia-induced tumor cell migration

PubMed Central

Zhang, Qinghong; Wang, Su-Yan; Nottke, Amanda C.; Rocheleau, Jonathan V.; Piston, David W.; Goodman, Richard H.

2006-01-01

The rapid growth and poor vascularization of solid tumors expose cancer cells to hypoxia, which promotes the metastatic phenotype by reducing intercellular adhesion and increasing cell motility and invasiveness. In this study, we found that hypoxia increased free NADH levels in cancer cells, promoting CtBP recruitment to the E-cadherin promoter. This effect was blocked by pyruvate, which prevents the NADH increase. Furthermore, hypoxia repressed E-cadherin gene expression and increased tumor cell migration, effects that were blocked by CtBP knockdown. We propose that CtBP senses levels of free NADH to control expression of cell adhesion genes, thereby promoting tumor cell migration under hypoxic stress. PMID:16740659

Focal adhesions and Ras are functionally and spatially integrated to mediate IL-1 activation of ERK

PubMed Central

Wang, Qin; Downey, Gregory P.; McCulloch, Christopher A.

2011-01-01

In connective tissue cells, IL-1-induced ERK activation leading to matrix metalloproteinase (MMP)-3 expression is dependent on cooperative interactions between focal adhesions and the endoplasmic reticulum (ER). As Ras can be activated on the ER, we investigated the role of Ras in IL-1 signaling and focal adhesion formation. We found that constitutively active H-Ras, K-Ras or N-Ras enhanced focal adhesion maturation and β1-integrin activation. IL-1 promoted the accumulation of Ras isoforms in ER and focal adhesion fractions, as shown in cells cotransfected with GFP-tagged Ras isoforms and YFP-ER protein and by analysis of subcellular fractions enriched for ER or focal adhesion proteins. Dominant-negative H-Ras or K-Ras reduced accumulation of H-Ras and K-Ras in focal adhesions induced by IL-1 and also blocked ERK activation and focal adhesion maturation. Ras-GRF was enriched constitutively in focal adhesion fractions and was required for Ras recruitment to focal adhesions. We conclude that Ras activation and IL-1 signaling are interactive processes that regulate the maturation of focal adhesions, which, in turn, is required for ERK activation.—Wang, Q., Downey, G. P., McCulloch, C. A. Focal adhesions and Ras are functionally and spatially integrated to mediate IL-1 activation of ERK. PMID:21719512

Environment-friendly adhesives for surface bonding of wood-based flooring using natural tannin to reduce formaldehyde and TVOC emission.

PubMed

Kim, Sumin

2009-01-01

The objective of this research was to develop environment-friendly adhesives for face fancy veneer bonding of engineered flooring using the natural tannin form bark in the wood. The natural wattle tannin adhesive were used to replace UF resin in the formaldehyde-based resin system in order to reduce formaldehyde and volatile organic compound (VOC) emissions from the adhesives used between plywoods and fancy veneers. PVAc was added to the natural tannin adhesive to increase viscosity of tannin adhesive for surface bonding. For tannin/PVAc hybrid adhesives, 5%, 10%, 20% and 30% of PVAc to the natural tannin adhesives were added. tannin/PVAc hybrid adhesives showed better bonding than the commercial natural tannin adhesive with a higher level of wood penetration. The initial adhesion strength was sufficient to be maintained within the optimum initial tack range. The standard formaldehyde emission test (desiccator method), field and laboratory emission cell (FLEC) and VOC analyzer were used to determine the formaldehyde and VOC emissions from engineered flooring bonded with commercial the natural tannin adhesive and tannin/PVAc hybrid adhesives. By desiccator method and FLEC, the formaldehyde emission level of each adhesive showed the similar tendency. All adhesives satisfied the E(1) grade (below 1.5 mg/L) and E(0) grade (below 0.5 mg/L) with UV coating. VOC emission results by FLEC and VOC analyzer were different with the formaldehyde emission results. TVOC emission was slightly increased as adding PVAc.

The consequence of biologic graft processing on blood interface biocompatibility and mechanics.

PubMed

Van de Walle, Aurore B; Uzarski, Joseph S; McFetridge, Peter S

2015-09-01

Processing ex vivo derived tissues to reduce immunogenicity is an effective approach to create biologically complex materials for vascular reconstruction. Due to the sensitivity of small diameter vascular grafts to occlusive events, the effect of graft processing on critical parameters for graft patency, such as peripheral cell adhesion and wall mechanics, requires detailed analysis. Isolated human umbilical vein sections were used as model allogenic vascular scaffolds that were processed with either: 1. sodium dodecyl sulfate (SDS), 2. ethanol/acetone (EtAc), or 3. glutaraldehyde (Glu). Changes in material mechanics were assessed via uniaxial tensile testing. Peripheral cell adhesion to the opaque grafting material was evaluated using an innovative flow chamber that allows direct observation of the blood-graft interface under physiological shear conditions. All treatments modified the grafts tensile strain and stiffness properties, with physiological modulus values decreasing from Glu 240±12 kPa to SDS 210±6 kPa and EtAc 140±3 kPa, P<.001. Relative to glutaraldehyde treatments, neutrophil adhesion to the decellularized grafts increased, with no statistical difference observed between SDS or EtAc treatments. Early platelet adhesion (% surface coverage) showed no statistical difference between the three treatments; however, quantification of platelet aggregates was significantly higher on SDS scaffolds compared to EtAc or Glu. Tissue processing strategies applied to the umbilical vein scaffold were shown to modify structural mechanics and cell adhesion properties, with the EtAc treatment reducing thrombotic events relative to SDS treated samples. This approach allows time and cost effective prescreening of clinically relevant grafting materials to assess initial cell reactivity.

Epithelial self-healing is recapitulated by a 3D biomimetic E-cadherin junction.

PubMed

Cohen, Daniel J; Gloerich, Martijn; Nelson, W James

2016-12-20

Epithelial monolayers undergo self-healing when wounded. During healing, cells collectively migrate into the wound site, and the converging tissue fronts collide and form a stable interface. To heal, migrating tissues must form cell-cell adhesions and reorganize from the front-rear polarity characteristic of cell migration to the apical-basal polarity of an epithelium. However, identifying the "stop signal" that induces colliding tissues to cease migrating and heal remains an open question. Epithelial cells form integrin-based adhesions to the basal extracellular matrix (ECM) and E-cadherin-mediated cell-cell adhesions on the orthogonal, lateral surfaces between cells. Current biological tools have been unable to probe this multicellular 3D interface to determine the stop signal. We addressed this problem by developing a unique biointerface that mimicked the 3D organization of epithelial cell adhesions. This "minimal tissue mimic" (MTM) comprised a basal ECM substrate and a vertical surface coated with purified extracellular domain of E-cadherin, and was designed for collision with the healing edge of an epithelial monolayer. Three-dimensional imaging showed that adhesions formed between cells, and the E-cadherin-coated MTM resembled the morphology and dynamics of native epithelial cell-cell junctions and induced the same polarity transition that occurs during epithelial self-healing. These results indicate that E-cadherin presented in the proper 3D context constitutes a minimum essential stop signal to induce self-healing. That the Ecad:Fc MTM stably integrated into an epithelial tissue and reduced migration at the interface suggests that this biointerface is a complimentary approach to existing tissue-material interfaces.

DDB2 (damaged-DNA binding 2) protein: a new modulator of nanomechanical properties and cell adhesion of breast cancer cells

NASA Astrophysics Data System (ADS)

Barbieux, Claire; Bacharouche, Jalal; Soussen, Charles; Hupont, Sébastien; Razafitianamaharavo, Angélina; Klotz, Rémi; Pannequin, Rémi; Brie, David; Bécuwe, Philippe; Francius, Grégory; Grandemange, Stéphanie

2016-02-01

DDB2, known for its role in DNA repair, was recently shown to reduce mammary tumor invasiveness by inducing the transcription of IκBα, an inhibitor of NF-κB activity. Since cellular adhesion is a key event during the epithelial to mesenchymal transition (EMT) leading to the invasive capacities of breast tumor cells, the aim of this study was to investigate the role of DDB2 in this process. Thus, using low and high DDB2-expressing MDA-MB231 and MCF7 cells, respectively, in which DDB2 expression was modulated experimentally, we showed that DDB2 overexpression was associated with a decrease of adhesion abilities on glass and plastic areas of breast cancer cells. Then, we investigated cell nanomechanical properties by atomic force microscopy (AFM). Our results revealed significant changes in the Young's Modulus value and the adhesion force in MDA-MB231 and MCF7 cells, whether DDB2 was expressed or not. The cell stiffness decrease observed in MDA-MB231 and MCF7 expressing DDB2 was correlated with a loss of the cortical actin-cytoskeleton staining. To understand how DDB2 regulates these processes, an adhesion-related gene PCR-Array was performed. Several adhesion-related genes were differentially expressed according to DDB2 expression, indicating that important changes are occurring at the molecular level. Thus, this work demonstrates that AFM technology is an important tool to follow cellular changes during tumorigenesis. Moreover, our data revealed that DDB2 is involved in early events occurring during metastatic progression of breast cancer cells and will contribute to define this protein as a new marker of metastatic progression in this type of cancer.

Blocking the Adhesion Cascade at the Premetastatic Niche for Prevention of Breast Cancer Metastasis

PubMed Central

Kang, Shin-Ae; Hasan, Nafis; Mann, Aman P; Zheng, Wei; Zhao, Lichao; Morris, Lynsie; Zhu, Weizhu; Zhao, Yan D; Suh, K Stephen; Dooley, William C; Volk, David; Gorenstein, David G; Cristofanilli, Massimo; Rui, Hallgeir; Tanaka, Takemi

2015-01-01

Shear-resistant adhesion and extravasation of disseminated cancer cells at the target organ is a crucial step in hematogenous metastasis. We found that the vascular adhesion molecule E-selectin preferentially promoted the shear-resistant adhesion and transendothelial migration of the estrogen receptor (ER)–/CD44+ hormone-independent breast cancer cells, but not of the ER+/CD44-/low hormone-dependent breast cancer cells. Coincidentally, CD44+ breast cancer cells were abundant in metastatic lung and brain lesions in ER– breast cancer, suggesting that E-selectin supports hematogenous metastasis of ER–/CD44+ breast cancer. In an attempt to prevent hematogenous metastasis through the inhibition of a shear-resistant adhesion of CD44+ cancer cells to E-selectin-expressing blood vessels on the premetastatic niche, an E-selectin targeted aptamer (ESTA) was developed. We demonstrated that a single intravenous injection of ESTA reduced metastases to a baseline level in both syngeneic and xenogeneic forced breast cancer metastasis models without relocating the site of metastasis. The effect of ESTA was absent in E-selectin knockout mice, suggesting that E-selectin is a molecular target of ESTA. Our data highlight the potential application of an E-selectin antagonist for the prevention of hematogenous metastasis of ER–/CD44+ breast cancer. PMID:25815697

Blocking the adhesion cascade at the premetastatic niche for prevention of breast cancer metastasis.

PubMed

Kang, Shin-Ae; Hasan, Nafis; Mann, Aman P; Zheng, Wei; Zhao, Lichao; Morris, Lynsie; Zhu, Weizhu; Zhao, Yan D; Suh, K Stephen; Dooley, William C; Volk, David; Gorenstein, David G; Cristofanilli, Massimo; Rui, Hallgeir; Tanaka, Takemi

2015-06-01

Shear-resistant adhesion and extravasation of disseminated cancer cells at the target organ is a crucial step in hematogenous metastasis. We found that the vascular adhesion molecule E-selectin preferentially promoted the shear-resistant adhesion and transendothelial migration of the estrogen receptor (ER)(-)/CD44(+) hormone-independent breast cancer cells, but not of the ER(+)/CD44(-/low) hormone-dependent breast cancer cells. Coincidentally, CD44(+) breast cancer cells were abundant in metastatic lung and brain lesions in ER(-) breast cancer, suggesting that E-selectin supports hematogenous metastasis of ER(-)/CD44(+) breast cancer. In an attempt to prevent hematogenous metastasis through the inhibition of a shear-resistant adhesion of CD44(+) cancer cells to E-selectin-expressing blood vessels on the premetastatic niche, an E-selectin targeted aptamer (ESTA) was developed. We demonstrated that a single intravenous injection of ESTA reduced metastases to a baseline level in both syngeneic and xenogeneic forced breast cancer metastasis models without relocating the site of metastasis. The effect of ESTA was absent in E-selectin knockout mice, suggesting that E-selectin is a molecular target of ESTA. Our data highlight the potential application of an E-selectin antagonist for the prevention of hematogenous metastasis of ER(-)/CD44(+) breast cancer.

Integrin activation by a cold atmospheric plasma jet

NASA Astrophysics Data System (ADS)

Volotskova, Olga; Stepp, Mary Ann; Keidar, Michael

2012-05-01

Current breakthrough research on cold atmospheric plasma (CAP) demonstrates that CAP has great potential in various areas, including medicine and biology, thus providing a new tool for living tissue treatment. In this paper, we explore potential mechanisms by which CAP alters cell migration and influences cell adhesion. We focus on the study of CAP interaction with fibroblasts and corneal epithelial cells. The data show that fibroblasts and corneal epithelial cells have different thresholds (treatment times) required to achieve maximum inhibition of cell migration. Both cell types reduced their migration rates by ˜30-40% after CAP compared to control cells. Also, the impact of CAP treatment on cell migration and persistence of fibroblasts after integrin activation by MnCl2, serum starvation or replating cells onto surfaces coated with integrin ligands is assessed; the results show that activation by MnCl2 or starvation attenuates cells’ responses to plasma. Studies carried out to assess the impact of CAP treatment on the activation state of β1 integrin and focal adhesion size by using immunofluorescence show that fibroblasts have more active β1 integrin on their surface and large focal adhesions after CAP treatment. Based on these data, a thermodynamic model is presented to explain how CAP leads to integrin activation and focal adhesion assembly.

N-cadherin adhesive interactions modulate matrix mechanosensing and fate commitment of mesenchymal stem cells

NASA Astrophysics Data System (ADS)

Cosgrove, Brian D.; Mui, Keeley L.; Driscoll, Tristan P.; Caliari, Steven R.; Mehta, Kush D.; Assoian, Richard K.; Burdick, Jason A.; Mauck, Robert L.

2016-12-01

During mesenchymal development, the microenvironment gradually transitions from one that is rich in cell-cell interactions to one that is dominated by cell-ECM (extracellular matrix) interactions. Because these cues cannot readily be decoupled in vitro or in vivo, how they converge to regulate mesenchymal stem cell (MSC) mechanosensing is not fully understood. Here, we show that a hyaluronic acid hydrogel system enables, across a physiological range of ECM stiffness, the independent co-presentation of the HAVDI adhesive motif from the EC1 domain of N-cadherin and the RGD adhesive motif from fibronectin. Decoupled presentation of these cues revealed that HAVDI ligation (at constant RGD ligation) reduced the contractile state and thereby nuclear YAP/TAZ localization in MSCs, resulting in altered interpretation of ECM stiffness and subsequent changes in downstream cell proliferation and differentiation. Our findings reveal that, in an evolving developmental context, HAVDI/N-cadherin interactions can alter stem cell perception of the stiffening extracellular microenvironment.

Mucin- and carbohydrate-stimulated adhesion and subproteome changes of the probiotic bacterium Lactobacillus acidophilus NCFM.

PubMed

Celebioglu, Hasan Ufuk; Olesen, Sita Vaag; Prehn, Kennie; Lahtinen, Sampo J; Brix, Susanne; Abou Hachem, Maher; Svensson, Birte

2017-06-23

Adhesion to intestinal mucosa is a crucial property for probiotic bacteria. Adhesion is thought to increase host-bacterial interactions, thus potentially enabling health benefits to the host. Molecular events connected with adhesion and surface proteome changes were investigated for the probiotic Lactobacillus acidophilus NCFM cultured with established or emerging prebiotic carbohydrates as carbon source and in the presence of mucin, the glycoprotein of the epithelial mucus layer. Variation in adhesion to HT29-cells and mucin was associated with carbon source and mucin-induced subproteome abundancy differences. Specifically, while growth on fructooligosaccharides (FOS) only stimulated adhesion to intestinal HT-29 cells, cellobiose and polydextrose in addition increased adhesion to mucin. Adhesion to HT-29 cells increased by about 2-fold for bacteria grown on mucin-supplemented glucose. Comparative 2DE-MS surface proteome analysis showed different proteins in energy metabolism appearing on the surface, suggesting they exert moonlighting functions. Mucin-supplemented bacteria had relative abundance of pyruvate kinase and fructose-bisphosphate aldolase increased by about 2-fold while six spots with 3.2-2.1 fold reduced relative abundance comprised elongation factor G, phosphoglycerate kinase, BipAEFTU family GTP-binding protein, ribonucleoside triphosphate reductase, adenylosuccinate synthetase, 30S ribosomal protein S1, and manganese-dependent inorganic pyrophosphatase. Surface proteome of cellobiose- compared to glucose-grown L. acidophilus NCFM had phosphate starvation inducible protein stress-related, thermostable pullulanase, and elongation factor G increasing 4.4-2.4 fold, while GAPDH, elongation factor Ts, and pyruvate kinase were reduced by 2.0-1.5 fold in relative abundance. Addition of recombinant L. acidophilus NCFM elongation factor G and pyruvate kinase to a coated mucin layer significantly suppressed subsequent adhesion of the bacterium. Human diet is important for intestinal health and food components, especially non-digestible carbohydrates can beneficially modify the microbiota. In the present study, effects of emerging and established prebiotic carbohydrates on the probiotic potential of Lactobacillus acidophilus NCFM were investigated by testing adhesion to a mucin layer and intestinal cells, and comparing this with changes in abundancy of surface proteins thought to be important for host interactions. Increased adhesion was observed following culturing of the bacterium with fructooligosaccharides, cellobiose or polydextrose, as well as mucin-supplemented glucose as carbon source. Enhanced adhesion ability can prolong bacterial residence in GIT yielding positive health effects. Higher relative abundance of certain surface proteins under various conditions (i.e. grown on cellobiose or mucin-supplemented glucose) suggested involvement of these proteins in adhesion, as confirmed by competition in case of two recombinantly produced moonlighting proteins. Combination of Lactobacillus acidophilus NCFM with different carbohydrates revealed potential bacterial determinants of synbiotic interactions, including stimulation of adhesion. Copyright © 2017 Elsevier B.V. All rights reserved.

Cyclophilin B induces integrin-mediated cell adhesion by a mechanism involving CD98-dependent activation of protein kinase C-delta and p44/42 mitogen-activated protein kinases.

PubMed

Melchior, Aurélie; Denys, Agnès; Deligny, Audrey; Mazurier, Joël; Allain, Fabrice

2008-02-01

Initially identified as a cyclosporin-A binding protein, cyclophilin B (CyPB) is an inflammatory mediator that induces adhesion of T lymphocytes to fibronectin, by a mechanism dependent on CD147 and alpha 4 beta 1 integrins. Recent findings have suggested that another cell membrane protein, CD98, may cooperate with CD147 to regulate beta1 integrin functions. Based on these functional relationships, we examined the contribution of CD98 in the pro-adhesive activity of CyPB, by utilizing the responsive promonocyte cell line THP-1. We demonstrated that cross-linking CD98 with CD98-AHN-18 antibody mimicked the responses induced by CyPB, i.e. homotypic aggregation, integrin-mediated adhesion to fibronectin and activation of p44/42 MAPK. Consistent with previous data, immunoprecipitation confirmed the existence of a heterocomplex wherein CD147, CD98 and beta1 integrins were associated. We then demonstrated that CyPB-induced cell adhesion and p44/42 MAPK activation were dependent on the participation of phosphoinositide 3-kinase and subsequent activation of protein kinase C-delta. Finally, silencing the expression of CD98 by RNA interference potently reduced CyPB-induced cell responses, thus confirming the role of CD98 in the pro-adhesive activity of CyPB. Altogether, our results support a model whereby CyPB induces integrin-mediated adhesion via interaction with a multimolecular unit formed by the association between CD147, CD98 and beta1 integrins.

Early Adhesion of Candida albicans onto Dental Acrylic Surfaces.

PubMed

Aguayo, S; Marshall, H; Pratten, J; Bradshaw, D; Brown, J S; Porter, S R; Spratt, D; Bozec, L

2017-07-01

Denture-associated stomatitis is a common candidal infection that may give rise to painful oral symptoms, as well as be a reservoir for infection at other sites of the body. As poly (methyl methacrylate) (PMMA) remains the main material employed in the fabrication of dentures, the aim of this research was to evaluate the adhesion of Candida albicans cells onto PMMA surfaces by employing an atomic force microscopy (AFM) single-cell force spectroscopy (SCFS) technique. For experiments, tipless AFM cantilevers were functionalized with PMMA microspheres and probed against C. albicans cells immobilized onto biopolymer-coated substrates. Both a laboratory strain and a clinical isolate of C. albicans were used for SCFS experiments. Scanning electron microscopy (SEM) and AFM imaging of C. albicans confirmed the polymorphic behavior of both strains, which was dependent on growth culture conditions. AFM force-spectroscopy results showed that the adhesion of C. albicans to PMMA is morphology dependent, as hyphal tubes had increased adhesion compared with yeast cells ( P < 0.05). C. albicans budding mother cells were found to be nonadherent, which contrasts with the increased adhesion observed in the tube region. Comparison between strains demonstrated increased adhesion forces for a clinical isolate compared with the lab strain. The clinical isolate also had increased survival in blood and reduced sensitivity to complement opsonization, providing additional evidence of strain-dependent differences in Candida-host interactions that may affect virulence. In conclusion, PMMA-modified AFM probes have shown to be a reliable technique to characterize the adhesion of C. albicans to acrylic surfaces.

Multi-functional electrospun antibacterial core-shell nanofibrous membranes for prolonged prevention of post-surgical tendon adhesion and inflammation.

PubMed

Shalumon, K T; Sheu, Chialin; Chen, Chih-Hao; Chen, Shih-Heng; Jose, Gils; Kuo, Chang-Yi; Chen, Jyh-Ping

2018-05-01

The possibility of endowing an electrospun anti-adhesive barrier membrane with multi-functionality, such as lubrication, prevention of fibroblast attachment and anti-infection and anti-inflammation properties, is highly desirable for the management of post-surgical tendon adhesion. To this end, we fabricated core-shell nanofibrous membranes (CSNMs) with embedded silver nanoparticles (Ag NPs) in the poly(ethylene glycol) (PEG)/poly(caprolactone) (PCL) shell and hyaluronic acid (HA)/ibuprofen in the core. HA imparted a lubrication effect for smooth tendon gliding and reduced fibroblast attachment, while Ag NPs and ibuprofen functioned as anti-infection and anti-inflammation agents, respectively. CSNMs with a PEG/PCL/Ag shell (PPA) and HA core containing 0% (H/PPA), 10% (HI10/PPA), 30% (HI30/PPA) and 50% (HI50/PPA) ibuprofen were fabricated through co-axial electrospinning and assessed through microscopic, spectroscopic, thermal, mechanical and drug release analyses. Considering nutrient passage through the barrier, the microporous CSNMs exerted the same barrier effect but drastically increased the mass transfer coefficients of bovine serum albumin compared with the commercial anti-adhesive membrane SurgiWrap®. Cell attachment/focal adhesion formation of fibroblasts revealed effective reduction of initial cell attachment on the CSNM surface with minimum cytotoxicity (except HI50/PPA). The anti-bacterial effect against both Gram-negative and Gram-positive bacteria was verified to be due to the Ag NPs in the membranes. In vivo studies using H/PPA and HI30/PPA CSNMs and SurgiWrap® in a rabbit flexor tendon rupture model demonstrated the improved efficacy of HI30/PPA CSNMs in reducing inflammation and tendon adhesion formation based on gross observation, histological analysis and functional assays. We conclude that HI30/PPA CSNMs can act as a multifunctional barrier membrane to prevent peritendinous adhesion after tendon surgery. A multi-functional anti-adhesion barrier membrane that could reduce fibroblasts attachment and penetration while simultaneously prevent post-surgical infection and inflammation is urgently needed. To this end, we prepared electrospun core-shell hyaluronic acid + ibuprofen/polyethylene glycol + polycaprolactone + Ag nanoparticles nanofibrous membranes by co-axial electrospinning as an ideal anti-adhesive membrane. The core-shell structure could meet the need of a desirable anti-adhesion barrier through release of ibuprofen and Ag nanoparticles to reduce infection and inflammation while hyaluronic acid can reduce fibroblasts adhesion. The superior performance of this multi-functional core-shell nanofibrous membrane in preventing peritendinous adhesion and post-surgical inflammation was demonstrated in a rabbit flexor tendon rupture model. Copyright © 2018 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Impact of O-glycosylation on the molecular and cellular adhesion properties of the Escherichia coli autotransporter protein Ag43.

PubMed

Reidl, Sebastian; Lehmann, Annika; Schiller, Roswitha; Salam Khan, A; Dobrindt, Ulrich

2009-08-01

Antigen 43 (Ag43) represents an entire family of closely related autotransporter proteins in Escherichia coli and has been described to confer aggregation and fluffing of cells, to promote biofilm formation, uptake and survival in macrophages as well as long-term persistence of uropathogenic E. coli in the murine urinary tract. Furthermore, it has been reported that glycosylation of the Ag43 passenger domain (alpha(43)) stabilizes its conformation and increases adhesion to Hep-2 cells. We characterized the role of Ag43 as an adhesin and the impact of O-glycosylation on the function of Ag43. To analyze whether structural variations in the alpha(43) domain correlate with different functional properties, we cloned 5 different agn43 alleles from different E. coli subtypes and tested them for autoaggregation, biofilm formation, adhesion to different eukaryotic cell lines as well as to purified components of the extracellular matrix. These experiments were performed with nonglycosylated and O-glycosylated Ag43 variants. We show for the first time that Ag43 mediates bacterial adhesion in a cell line-specific manner and that structural variations of the alpha(43) domain correlate with increased adhesive properties to proteins of the extracellular matrix such as collagen and laminin. Whereas O-glycosylation of many alpha(43) domains led to impaired autoaggregation and a significantly reduced adhesion to eukaryotic cell lines, their interaction with collagen was significantly increased. These data demonstrate that O-glycosylation is not a prerequisite for Ag43 function and that the different traits mediated by Ag43, i.e., biofilm formation, autoaggregation, adhesion to eukaryotic cells and extracellular matrix proteins, rely on distinct mechanisms.

Targeting In-Stent-Stenosis with RGD- and CXCL1-Coated Mini-Stents in Mice.

PubMed

Simsekyilmaz, Sakine; Liehn, Elisa A; Weinandy, Stefan; Schreiber, Fabian; Megens, Remco T A; Theelen, Wendy; Smeets, Ralf; Jockenhövel, Stefan; Gries, Thomas; Möller, Martin; Klee, Doris; Weber, Christian; Zernecke, Alma

2016-01-01

Atherosclerotic lesions that critically narrow the artery can necessitate an angioplasty and stent implantation. Long-term therapeutic effects, however, are limited by excessive arterial remodeling. We here employed a miniaturized nitinol-stent coated with star-shaped polyethylenglycole (star-PEG), and evaluated its bio-functionalization with RGD and CXCL1 for improving in-stent stenosis after implantation into carotid arteries of mice. Nitinol foils or stents (bare metal) were coated with star-PEG, and bio-functionalized with RGD, or RGD/CXCL1. Cell adhesion to star-PEG-coated nitinol foils was unaltered or reduced, whereas bio-functionalization with RGD but foremost RGD/CXCL1 increased adhesion of early angiogenic outgrowth cells (EOCs) and endothelial cells but not smooth muscle cells when compared with bare metal foils. Stimulation of cells with RGD/CXCL1 furthermore increased the proliferation of EOCs. In vivo, bio-functionalization with RGD/CXCL1 significantly reduced neointima formation and thrombus formation, and increased re-endothelialization in apoE-/- carotid arteries compared with bare-metal nitinol stents, star-PEG-coated stents, and stents bio-functionalized with RGD only. Bio-functionalization of star-PEG-coated nitinol-stents with RGD/CXCL1 reduced in-stent neointima formation. By supporting the adhesion and proliferation of endothelial progenitor cells, RGD/CXCL1 coating of stents may help to accelerate endothelial repair after stent implantation, and thus may harbor the potential to limit the complication of in-stent restenosis in clinical approaches.

Targeting In-Stent-Stenosis with RGD- and CXCL1-Coated Mini-Stents in Mice

PubMed Central

Weinandy, Stefan; Schreiber, Fabian; Megens, Remco T. A.; Theelen, Wendy; Smeets, Ralf; Jockenhövel, Stefan; Gries, Thomas; Möller, Martin; Klee, Doris; Weber, Christian; Zernecke, Alma

2016-01-01

Atherosclerotic lesions that critically narrow the artery can necessitate an angioplasty and stent implantation. Long-term therapeutic effects, however, are limited by excessive arterial remodeling. We here employed a miniaturized nitinol-stent coated with star-shaped polyethylenglycole (star-PEG), and evaluated its bio-functionalization with RGD and CXCL1 for improving in-stent stenosis after implantation into carotid arteries of mice. Nitinol foils or stents (bare metal) were coated with star-PEG, and bio-functionalized with RGD, or RGD/CXCL1. Cell adhesion to star-PEG-coated nitinol foils was unaltered or reduced, whereas bio-functionalization with RGD but foremost RGD/CXCL1 increased adhesion of early angiogenic outgrowth cells (EOCs) and endothelial cells but not smooth muscle cells when compared with bare metal foils. Stimulation of cells with RGD/CXCL1 furthermore increased the proliferation of EOCs. In vivo, bio-functionalization with RGD/CXCL1 significantly reduced neointima formation and thrombus formation, and increased re-endothelialization in apoE-/- carotid arteries compared with bare-metal nitinol stents, star-PEG-coated stents, and stents bio-functionalized with RGD only. Bio-functionalization of star-PEG-coated nitinol-stents with RGD/CXCL1 reduced in-stent neointima formation. By supporting the adhesion and proliferation of endothelial progenitor cells, RGD/CXCL1 coating of stents may help to accelerate endothelial repair after stent implantation, and thus may harbor the potential to limit the complication of in-stent restenosis in clinical approaches. PMID:27192172

Deoxycholic acid promotes development of gastroesophageal reflux disease and Barrett's oesophagus by modulating integrin-αv trafficking.

PubMed

Prichard, David O; Byrne, Anne Marie; Murphy, James O; Reynolds, John V; O'Sullivan, Jacintha; Feighery, Ronan; Doyle, Brendan; Eldin, Osama Sharaf; Finn, Stephen P; Maguire, Aoife; Duff, Deirdre; Kelleher, Dermot P; Long, Aideen

2017-12-01

The fundamental mechanisms underlying erosive oesophagitis and subsequent development of Barrett's oesophagus (BO) are poorly understood. Here, we investigated the contribution of specific components of the gastric refluxate on adhesion molecules involved in epithelial barrier maintenance. Cell line models of squamous epithelium (HET-1A) and BO (QH) were used to examine the effects of bile acids on cell adhesion to extracellular matrix proteins (Collagen, laminin, vitronectin, fibronectin) and expression of integrin ligands (α 3 , α 4, α 5 , α 6 and α ν ). Experimental findings were validated in human explant oesophageal biopsies, a rat model of gastroesophageal reflux disease (GORD) and in patient tissue microarrays. The bile acid deoxycholic acid (DCA) specifically reduced adhesion of HET-1A cells to vitronectin and reduced cell-surface expression of integrin-α ν via effects on endocytic recycling processes. Increased expression of integrin-α v was observed in ulcerated tissue in a rat model of GORD and in oesophagitis and Barrett's intestinal metaplasia patient tissue compared to normal squamous epithelium. Increased expression of integrin-α ν was observed in QH BO cells compared to HET-1A cells. QH cells were resistant to DCA-mediated loss of adhesion and reduction in cell-surface expression of integrin-α ν . We demonstrated that a specific component of the gastric refluxate, DCA, affects the epithelial barrier through modulation of integrin α ν expression, providing a novel mechanism for bile acid-mediated erosion of oesophageal squamous epithelium and promotion of BO. Strategies aimed at preventing bile acid-mediated erosion should be considered in the clinical management of patients with GORD. © 2017 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

Rho-ROCK signaling differentially regulates chondrocyte spreading on fibronectin and bone sialoprotein.

PubMed

Gill, Kamal S; Beier, Frank; Goldberg, Harvey A

2008-07-01

The mammalian growth plate is a dynamic structure rich in extracellular matrix (ECM). Interactions of growth plate chondrocytes with ECM proteins regulate cell behavior. In this study, we compared chondrocyte adhesion and spreading dynamics on fibronectin (FN) and bone sialoprotein (BSP). Chondrocyte adhesion and spreading were also compared with fibroblasts to analyze potential cell-type-specific effects. Chondrocyte adhesion to BSP is independent of posttranslational modifications but is dependent on the RGD sequence in BSP. Whereas chondrocytes and fibroblasts adhered at similar levels on FN and BSP, cells displayed more actin-dependent spread on FN despite a 16x molar excess of BSP adsorbed to plastic. To identify intracellular mediators responsible for this difference in spreading, we investigated focal adhesion kinase (FAK)-Src and Rho-Rho kinase (ROCK) signaling. Although activated FAK localized to the vertices of adhered chondrocytes, levels of FAK activation did not correlate with the extent of spreading. Furthermore, Src inhibition reduced chondrocyte spreading on both FN and BSP, suggesting that FAK-Src signaling is not responsible for less cell spreading on BSP. In contrast, inhibition of Rho and ROCK in chondrocytes increased cell spreading on BSP and membrane protrusiveness on FN but did not affect cell adhesion. In fibroblasts, Rho inhibition increased fibroblast spreading on BSP while ROCK inhibition changed membrane protrusiveness of FN and BSP. In summary, we identify a novel role for Rho-ROCK signaling in regulating chondrocyte spreading and demonstrate both cell- and matrix molecule-specific mechanisms controlling cell spreading.

Rho-ROCK signaling differentially regulates chondrocyte spreading on fibronectin and bone sialoprotein

PubMed Central

Gill, Kamal S.; Beier, Frank; Goldberg, Harvey A.

2008-01-01

The mammalian growth plate is a dynamic structure rich in extracellular matrix (ECM). Interactions of growth plate chondrocytes with ECM proteins regulate cell behavior. In this study, we compared chondrocyte adhesion and spreading dynamics on fibronectin (FN) and bone sialoprotein (BSP). Chondrocyte adhesion and spreading were also compared with fibroblasts to analyze potential cell-type-specific effects. Chondrocyte adhesion to BSP is independent of posttranslational modifications but is dependent on the RGD sequence in BSP. Whereas chondrocytes and fibroblasts adhered at similar levels on FN and BSP, cells displayed more actin-dependent spread on FN despite a 16× molar excess of BSP adsorbed to plastic. To identify intracellular mediators responsible for this difference in spreading, we investigated focal adhesion kinase (FAK)-Src and Rho-Rho kinase (ROCK) signaling. Although activated FAK localized to the vertices of adhered chondrocytes, levels of FAK activation did not correlate with the extent of spreading. Furthermore, Src inhibition reduced chondrocyte spreading on both FN and BSP, suggesting that FAK-Src signaling is not responsible for less cell spreading on BSP. In contrast, inhibition of Rho and ROCK in chondrocytes increased cell spreading on BSP and membrane protrusiveness on FN but did not affect cell adhesion. In fibroblasts, Rho inhibition increased fibroblast spreading on BSP while ROCK inhibition changed membrane protrusiveness of FN and BSP. In summary, we identify a novel role for Rho-ROCK signaling in regulating chondrocyte spreading and demonstrate both cell- and matrix molecule-specific mechanisms controlling cell spreading. PMID:18463228

Why do receptor–ligand bonds in cell adhesion cluster into discrete focal-adhesion sites?

DOE PAGES

Gao, Zhiwen; Gao, Yanfei

2016-05-14

We report that cell adhesion often exhibits the clustering of the receptor–ligand bonds into discrete focal-adhesion sites near the contact edge, thus resembling a rosette shape or a contracting membrane anchored by a small number of peripheral forces. The ligands on the extracellular matrix are immobile, and the receptors in the cell plasma membrane consist of two types: high-affinity integrins (that bond to the substrate ligands and are immobile) and low-affinity integrins (that are mobile and not bonded to the ligands). Thus the adhesion energy density is proportional to the high-affinity integrin density. This paper provides a mechanistic explanation formore » the clustering/assembling of the receptor–ligand bonds from two main points: (1) the cellular contractile force leads to the density evolution of these two types of integrins, and results into a large high-affinity integrin density near the contact edge and (2) the front of a propagating crack into a decreasing toughness field will be unstable and wavy. From this fracture mechanics perspective, the chemomechanical equilibrium is reached when a small number of patches with large receptor–ligand bond density are anticipated to form at the cell periphery, as opposed to a uniform distribution of bonds on the entire interface. Finally, cohesive fracture simulations show that the de-adhesion force can be significantly enhanced by this nonuniform bond density field, but the de-adhesion force anisotropy due to the substrate elastic anisotropy is significantly reduced.« less

Control of bacterial adhesion and growth on honeycomb-like patterned surfaces.

PubMed

Yang, Meng; Ding, Yonghui; Ge, Xiang; Leng, Yang

2015-11-01

It is a great challenge to construct a persistent bacteria-resistant surface even though it has been demonstrated that several surface features might be used to control bacterial behavior, including surface topography. In this study, we develop micro-scale honeycomb-like patterns of different sizes (0.5-10 μm) as well as a flat area as the control on a single platform to evaluate the bacterial adhesion and growth. Bacteria strains, Escherichia coli and Staphylococcus aureus with two distinct shapes (rod and sphere) are cultured on the platforms, with the patterned surface-up and surface-down in the culture medium. The results demonstrate that the 1 μm patterns remarkably reduce bacterial adhesion and growth while suppressing bacterial colonization when compared to the flat surface. The selective adhesion of the bacterial cells on the patterns reveals that the bacterial adhesion is cooperatively mediated by maximizing the cell-substrate contact area and minimizing the cell deformation, from a thermodynamic point of view. Moreover, study of bacterial behaviors on the surface-up vs. surface-down samples shows that gravity does not apparently affect the spatial distribution of the adherent cells although it indeed facilitates bacterial adhesion. Furthermore, the experimental results suggest that two major factors, i.e. the availability of energetically favorable adhesion sites and the physical confinements, contribute to the anti-bacterial nature of the honeycomb-like patterns. Copyright © 2015 Elsevier B.V. All rights reserved.

Why do receptor–ligand bonds in cell adhesion cluster into discrete focal-adhesion sites?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gao, Zhiwen; Gao, Yanfei

We report that cell adhesion often exhibits the clustering of the receptor–ligand bonds into discrete focal-adhesion sites near the contact edge, thus resembling a rosette shape or a contracting membrane anchored by a small number of peripheral forces. The ligands on the extracellular matrix are immobile, and the receptors in the cell plasma membrane consist of two types: high-affinity integrins (that bond to the substrate ligands and are immobile) and low-affinity integrins (that are mobile and not bonded to the ligands). Thus the adhesion energy density is proportional to the high-affinity integrin density. This paper provides a mechanistic explanation formore » the clustering/assembling of the receptor–ligand bonds from two main points: (1) the cellular contractile force leads to the density evolution of these two types of integrins, and results into a large high-affinity integrin density near the contact edge and (2) the front of a propagating crack into a decreasing toughness field will be unstable and wavy. From this fracture mechanics perspective, the chemomechanical equilibrium is reached when a small number of patches with large receptor–ligand bond density are anticipated to form at the cell periphery, as opposed to a uniform distribution of bonds on the entire interface. Finally, cohesive fracture simulations show that the de-adhesion force can be significantly enhanced by this nonuniform bond density field, but the de-adhesion force anisotropy due to the substrate elastic anisotropy is significantly reduced.« less

Homing of human B cells to lymphoid organs and B-cell lymphoma engraftment are controlled by cell adhesion molecule JAM-C.

PubMed

Doñate, Carmen; Ody, Christiane; McKee, Thomas; Ruault-Jungblut, Sylvie; Fischer, Nicolas; Ropraz, Patricia; Imhof, Beat A; Matthes, Thomas

2013-01-15

Junctional adhesion molecule C (JAM-C) is expressed by vascular endothelium and human but not mouse B lymphocytes. The level of JAM-C expression defines B-cell differentiation stages and allows the classification of marginal zone-derived (JAM-C-positive) and germinal center-derived (JAM-C-negative) B-cell lymphomas. In the present study, we investigated the role of JAM-C in homing of human B cells, using a xenogeneic nonobese diabetic/severe combined immunodeficient mouse model. Treatment with anti-JAM-C antibodies in short-term experiments reduced migration of normal and malignant JAM-C-expressing B cells to bone marrow, lymph nodes, and spleen. Blocking homing to the spleen is remarkable, as most other antiadhesion antibodies reduce homing of B cells only to bone marrow and lymph nodes. Long-term administration of anti-JAM-C antibodies prevented engraftment of JAM-Cpos lymphoma cells in bone marrow, spleen, and lymph nodes of mice. Plasmon resonance studies identified JAM-B as the major ligand for JAM-C, whereas homotypic JAM-C interactions remained at background levels. Accordingly, anti-JAM-C antibodies blocked adhesion of JAM-C-expressing B cells to their ligand JAM-B, and immunofluorescence analysis showed the expression of JAM-B on murine and human lymphatic endothelial cells. Targeting JAM-C could thus constitute a new therapeutic strategy to prevent lymphoma cells from reaching supportive microenvironments not only in the bone marrow and lymph nodes but also in the spleen.

Extravasation of adhering vesicles

NASA Astrophysics Data System (ADS)

Tordeux, C.; Fournier, J.-B.

2002-12-01

We study how the passage of lipid vesicles through a small pore can be induced by the difference in non-specific adhesion energy between the two sides of the substrate bearing the pore. This process is inspired from the extravasation of cells or liposomes from blood vessels, which involves adhesion binders. We study the adhesion-dominated regime and we show that the passage of a vesicle of volume V and area A is selective in terms of the reduced volume v ~ V/A3/2. Extravasation occurs for adhesion ratios of order unity. We also consider the possibility of pressure-induced extravasation in the presence of adhesion. Finally, we propose a micro-device based on adhesion-induced extravasation, which is designed to sort vesicles according to their deflatedness.

Cell wall structures leading to cultivar differences in softening rates develop early during apple (Malus x domestica) fruit growth.

PubMed

Ng, Jovyn K T; Schröder, Roswitha; Sutherland, Paul W; Hallett, Ian C; Hall, Miriam I; Prakash, Roneel; Smith, Bronwen G; Melton, Laurence D; Johnston, Jason W

2013-11-19

There is a paucity of information regarding development of fruit tissue microstructure and changes in the cell walls during fruit growth, and how these developmental processes differ between cultivars with contrasting softening behaviour. In this study we compare two apple cultivars that show different softening rates during fruit development and ripening. We investigate whether these different softening behaviours manifest themselves late during ethylene-induced softening in the ripening phase, or early during fruit expansion and maturation. 'Scifresh' (slow softening) and 'Royal Gala' (rapid softening) apples show differences in cortical microstructure and cell adhesion as early as the cell expansion phase. 'Scifresh' apples showed reduced loss of firmness and greater dry matter accumulation compared with 'Royal Gala' during early fruit development, suggesting differences in resource allocation that influence tissue structural properties. Tricellular junctions in 'Scifresh' were rich in highly-esterified pectin, contributing to stronger cell adhesion and an increased resistance to the development of large airspaces during cell expansion. Consequently, mature fruit of 'Scifresh' showed larger, more angular shaped cells than 'Royal Gala', with less airspaces and denser tissue. Stronger cell adhesion in ripe 'Scifresh' resulted in tissue fracture by cell rupture rather than by cell-to-cell-separation as seen in 'Royal Gala'. CDTA-soluble pectin differed in both cultivars during development, implicating its involvement in cell adhesion. Low pectin methylesterase activity during early stages of fruit development coupled with the lack of immuno-detectable PG was associated with increased cell adhesion in 'Scifresh'. Our results indicate that cell wall structures leading to differences in softening rates of apple fruit develop early during fruit growth and well before the induction of the ripening process.

Cell wall structures leading to cultivar differences in softening rates develop early during apple (Malus x domestica) fruit growth

PubMed Central

2013-01-01

Background There is a paucity of information regarding development of fruit tissue microstructure and changes in the cell walls during fruit growth, and how these developmental processes differ between cultivars with contrasting softening behaviour. In this study we compare two apple cultivars that show different softening rates during fruit development and ripening. We investigate whether these different softening behaviours manifest themselves late during ethylene-induced softening in the ripening phase, or early during fruit expansion and maturation. Results ‘Scifresh’ (slow softening) and ‘Royal Gala’ (rapid softening) apples show differences in cortical microstructure and cell adhesion as early as the cell expansion phase. ‘Scifresh’ apples showed reduced loss of firmness and greater dry matter accumulation compared with ‘Royal Gala’ during early fruit development, suggesting differences in resource allocation that influence tissue structural properties. Tricellular junctions in ‘Scifresh’ were rich in highly-esterified pectin, contributing to stronger cell adhesion and an increased resistance to the development of large airspaces during cell expansion. Consequently, mature fruit of ‘Scifresh’ showed larger, more angular shaped cells than ‘Royal Gala’, with less airspaces and denser tissue. Stronger cell adhesion in ripe ‘Scifresh’ resulted in tissue fracture by cell rupture rather than by cell-to-cell-separation as seen in ‘Royal Gala’. CDTA-soluble pectin differed in both cultivars during development, implicating its involvement in cell adhesion. Low pectin methylesterase activity during early stages of fruit development coupled with the lack of immuno-detectable PG was associated with increased cell adhesion in ‘Scifresh’. Conclusions Our results indicate that cell wall structures leading to differences in softening rates of apple fruit develop early during fruit growth and well before the induction of the ripening process. PMID:24252512

Hydroxyapatite promotes superior keratocyte adhesion and proliferation in comparison with current keratoprosthesis skirt materials.

PubMed

Mehta, J S; Futter, C E; Sandeman, S R; Faragher, R G A F; Hing, K A; Tanner, K E; Allan, B D S

2005-10-01

Published clinical series suggest the osteoodontokeratoprosthesis (OOKP) may have a lower extrusion rate than current synthetic keratoprostheses. The OOKP is anchored in the eye wall by autologous tooth. The authors' aim was to compare adhesion, proliferation, and morphology for telomerase transformed keratocytes seeded on calcium hydroxyapatite (the principal mineral constituent of tooth) and materials used in the anchoring elements of commercially available synthetic keratoprostheses. Test materials were hydroxyapatite, polytetrafluoroethylene (PTFE), polyhydroxyethyl methacrylate (HEMA), and glass (control). Cell adhesion and viability were quantified at 4 hours, 24 hours, and 1 week using a calcein-AM/EthD-1 viability/cytotoxicity assay. Focal contact expression and cytoskeletal organisation were studied at 24 hours by confocal microscopy with immunoflourescent labelling. Further studies of cell morphology were performed using light and scanning electron microscopy. Live cell counts were significantly greater on hydroxyapatite surfaces at each time point (p<0.04). Dead cell counts were significantly higher for PTFE at 7 days (p<0.002). ss(1) integrin expression was highest on hydroxyapatite. Adhesion structures were well expressed in flat, spread out keratocytes on both HA and glass. Keratocytes tended to be thinner and spindle shaped on PTFE. The relatively few keratocytes visible on HEMA test surfaces were rounded and poorly adherent. Keratocyte adhesion, spreading, and viability on hydroxyapatite test surfaces is superior to that seen on PTFE and HEMA. Improving the initial cell adhesion environment in the skirt element of keratoprostheses may enhance tissue integration and reduce device failure rates.

Numerical analysis of cell adhesion in capillary flow

NASA Astrophysics Data System (ADS)

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

2016-11-01

Numerical simulation of cell adhesion was performed for capillaries whose diameter is comparable to or smaller than that of the cell. Despite a lot of works about leukocyte and tumor cell rolling, cell motion in capillaries has remained unclear. The solid and fluid mechanics of a cell in flow was coupled with a slip bond model of ligand-receptor interactions. When the size of a capillary was reduced, the cell always transitioned to "bullet-like" motion, with a consequent decrease in the velocity of the cell. A state diagram is obtained for various values of capillary diameter and receptor density. According to our numerical results, bullet motion enables firm adhesion of a cell to the capillary wall even for a weak ligand-receptor binding. We also quantified effects of various parameters, including the dissociation rate constant, the spring constant, and the reactive compliance on the characteristics of cell motion. Our results suggest that even under the interaction between PSGL-1 and P-selectin, which is mainly responsible for leukocyte rolling, a cell is able to show firm adhesion in a small capillary. These findings may help in understanding such phenomena as leukocyte plugging and cancer metastasis. This research was supported by JSPS KAKENHI Grant Numbers 25000008, 26107703, 14J03967. We also acknowledge support from the Tohoku University Division for International Advanced Research and Education Organization.

Design and use of an artificial capillary in the study of metastatic cell adhesion

NASA Astrophysics Data System (ADS)

Rafi, Adam; Peramo, Antonio; Boren, Rebecca; Heim, August; Matthews, William G.

2006-03-01

To improve the quality of life of patients with cancer, treatments will need to both minimize existing tumors and reduce the metastasis of cancer cells. The effectiveness of potential treatments on existing tumors can be directly probed, but anti-metastasis treatments are difficult to quantify. Therefore, a detailed understanding of the metastatic process is required for drug design. Details of the metastatic deposition of tumor cells in the circulatory system are not well understood. We are investigating the binding of tumor cells to an artificial endothelium. The model system allows for control over molecular composition at the interface, presenting the proteoglycans (PGs) found in the glycocalyx to tumor cells under shear flow conditions. Whether rolling or static adhesion is preferred, as well as what mechanical properties of the interaction between the cells and the PGs are important is to be determined. The outcomes of these experiments will help guide the search for pharmaceuticals that can disrupt the metastatic process at the endothelial adhesion step.

Cleaved high-molecular-weight kininogen inhibits neointima formation following vascular injury.

PubMed

Daniel, Jan-Marcus; Reich, Fabian; Dutzmann, Jochen; Weisheit, Simona; Teske, Rebecca; Gündüz, Dursun; Bauersachs, Johann; Preissner, Klaus T; Sedding, Daniel G

2015-08-31

Cleaved high-molecular-weight kininogen (HKa) or its peptide domain 5 (D5) alone exert anti-adhesive properties in vitro related to impeding integrin-mediated cellular interactions. However, the anti-adhesive effects of HKa in vivo remain elusive. In this study, we investigated the effects of HKa on leukocyte recruitment and neointima formation following wire-induced injury of the femoral artery in C57BL/6 mice. Local application of HKa significantly reduced the accumulation of monocytes and also reduced neointimal lesion size 14 days after injury. Moreover, C57BL/6 mice transplanted with bone marrow from transgenic mice expressing enhanced green fluorescence protein (eGFP) showed a significantly reduced accumulation of eGFP+-cells at the arterial injury site and decreased neointimal lesion size after local application of HKa or the polypeptide D5 alone. A differentiation of accumulating eGFP+-cells into highly specific smooth muscle cells (SMC) was not detected in any group. In contrast, application of HKa significantly reduced the proliferation of locally derived neointimal cells. In vitro, HKa and D5 potently inhibited the adhesion of SMC to vitronectin, thus impairing their proliferation, migration, and survival rates. In conclusion, application of HKa or D5 decreases the inflammatory response to vascular injury and exerts direct effects on SMC by impeding the binding of integrins to extracellular matrix components. Therefore, HKa and D5 may hold promise as novel therapeutic substances to prevent neointima formation.

Estrogen and pure antiestrogen fulvestrant (ICI 182 780) augment cell–matrigel adhesion of MCF-7 breast cancer cells through a novel G protein coupled estrogen receptor (GPR30)-to-calpain signaling axis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Yan; Li, Zheng; He, Yan

2014-03-01

Fulvestrant (ICI 182 780, ICI) has been used in treating patients with hormone-sensitive breast cancer, yet initial or acquired resistance to endocrine therapies frequently arises and, in particular, cancer recurs as metastasis. We demonstrate here that both 17-beta-estradiol (E2) and ICI enhance cell adhesion to matrigel in MCF-7 breast cancer cells, with increased autolysis of calpain 1 (large subunit) and proteolysis of focal adhesion kinase (FAK), indicating calpain activation. Additionally, either E2 or ICI induced down-regulation of estrogen receptor α without affecting G protein coupled estrogen receptor 30 (GPR30) expression. Interestingly, GPR30 agonist G1 triggered calpain 1 autolysis but notmore » calpain 2, whereas ER agonist diethylstilbestrol caused no apparent calpain autolysis. Furthermore, the actions of E2 and ICI on calpain and cell adhesion were tremendously suppressed by G15, or knockdown of GPR30. E2 and ICI also induced phosphorylation of extracellular regulated protein kinases 1 and 2 (ERK1/2), and suppression of ERK1/2 phosphorylation by U0126 profoundly impeded calpain activation triggered by estrogenic and antiestrogenic stimulations indicating implication of ERK1/2 in the GPR30-mediated action. Lastly, the E2- or ICI-induced cell adhesion was dramatically impaired by calpain-specific inhibitors, ALLN or calpeptin, suggesting requirement of calpain in the GPR30-associated action. These data show that enhanced cell adhesion by E2 and ICI occurs via a novel GPR30-ERK1/2-calpain pathway. Our results indicate that targeting the GPR30 signaling may be a potential strategy to reduce metastasis and improve the efficacy of antiestrogens in treatment of advanced breast cancer. - Highlights: • Estrogen and ICI augment adhesion to matrigel with calpain activation in MCF-7 cells. • GPR30 mediates cell–matrigel adhesion and calpain activation via ERK1/2. • Calpain is required in the cell–matrigel adhesion induced by E2 and ICI.« less

Construction of a multifunctional coating consisting of phospholipids and endothelial progenitor cell-specific peptides on titanium substrates

NASA Astrophysics Data System (ADS)

Chen, Huiqing; Li, Xiaojing; Zhao, Yuancong; Li, Jingan; Chen, Jiang; Yang, Ping; Maitz, Manfred F.; Huang, Nan

2015-08-01

A phospholipid/peptide polymer (PMMDP) with phosphorylcholine groups, endothelial progenitor cell (EPC)-specific peptides and catechol groups was anchored onto a titanium (Ti) surface to fabricate a biomimetic multifunctional surface. The PMMDP coating was characterized by X-ray photoelectron spectroscopy (XPS), water contact angle measurements and atomic force microscopy (AFM), respectively. The amount of PMMDP coating on the Ti surface was quantified by using the quartz crystal microbalance with dissipation (QCM-D). Interactions between blood components and the coated and bare Ti substrates were evaluated by platelet adhesion and activation assays and fibrinogen denaturation test using platelet rich plasma (PRP). The results revealed that the PMMDP-modified surface inhibited fibrinogen denaturation and reduced platelet adhesion and activation. EPC cell culture on the PMMDP-modified surface showed increased adhesion and proliferation of EPCs when compared to the cells cultured on untreated Ti surface. The inhibition of fibrinogen denaturation and platelet adhesion and support of EPCs attachment and proliferation indicated that this coating might be beneficial for future applications in blood-contacting implants, such as vascular stents.

Selective Blockade of Cytoskeletal Actin Remodeling Reduces Experimental Choroidal Neovascularization

PubMed Central

Caballero, Sergio; Yang, Ru; Chaqour, Brahim

2011-01-01

Purpose. The efficacy of the peptide Ac-EEED on reducing cell adhesion and proliferation in vitro and choroidal neovascularization (CNV) in vivo was examined. Methods. The peptide chimera containing the Ac-EEED sequence was chemically linked to the N terminus of the XMTM delivery peptide from the Erns viral surface protein. Ac-EEED or scrambled control peptide (SCRAM) was added to cultures of vascular smooth muscle cells, pericytes, endothelial cells, and fibroblasts, and adhesion, growth, and matrix production was assessed. Ac-EEED or SCRAM was injected into the vitreous of mice undergoing laser rupture of Bruch's membrane to induce CNV and lesion volume, neovascularization and lesion fibrosis were assessed. Results. Ac-EEED–induced changes in the morphology of the actin cytoskeleton by inhibiting polymerization of G-actin and disrupting the formation of stress fibers. Pretreatment with Ac-EEED resulted in endothelial cells becoming less responsive to the mitogenic and pro-adhesive effects of VEGF. Ac-EEED treatment in fibroblasts reduced TGF-β–induced fibrosis as assessed by decreased levels of connective tissue growth factor, cysteine-rich 61, collagen I (COL1A2), and collagen III (COL3A1). CNV lesion size and fibrosis were reduced in a concentration-dependent manner by up to 60%. Conclusions. In vitro studies showed that Ac-EEED affects a broad range of mechanical properties associated with cytoskeletal actin to reduce growth factor effects. The utilization of Ac-EEED in vivo may offer a novel therapeutic strategy by both suppressed neovessel growth and curtailing fibrosis typically associated with the involutional stage of CNV. PMID:21178140

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Yoo-Shin; Lee, Tae Hoon; O'Neill, Brian E., E-mail: BEOneill@houstonmethodist.org

Non-lethal hyperthermia is used clinically as adjuvant treatment to radiation, with mixed results. Denaturation of protein during hyperthermia treatment is expected to synergize with radiation damage to cause cell cycle arrest and apoptosis. Alternatively, hyperthermia is known to cause tissue level changes in blood flow, increasing the oxygenation and radiosensitivity of often hypoxic tumors. In this study, we elucidate a third possibility, that hyperthermia alters cellular adhesion and mechanotransduction, with particular impact on the cancer stem cell population. We demonstrate that cell heating results in a robust but temporary loss of cancer cell aggressiveness and metastatic potential in mouse models.more » In vitro, this heating results in a temporary loss in cell mobility, adhesion, and proliferation. Our hypothesis is that the loss of cellular adhesion results in suppression of cancer stem cells and loss of tumor virulence and metastatic potential. Our study suggests that the metastatic potential of cancer is particularly reduced by the effects of heat on cellular adhesion and mechanotransduction. If true, this could help explain both the successes and failures of clinical hyperthermia, and suggest ways to target treatments to those who would most benefit. - Highlights: • Non-lethal hyperthermia treatment of cancer cells is shown to cause a reduction in rates of tumor initiation and metastasis. • Dynamic imaging of cells during heat treatment shows temporary changes in cell shape, cell migration, and cell proliferation. • Loss of adhesion may lead to the observed effect, which may disproportionately impact the tumor initiating cell fraction. • Loss or suppression of the tumor initiating cell fraction results in the observed loss of metastatic potential in vivo. • This result may lead to new approaches to synergizing hyperthermia with surgery, radiation, and chemotherapy.« less

Lateral adhesion drives reintegration of misplaced cells into epithelial monolayers

PubMed Central

St Johnston, Daniel

2016-01-01

Cells in simple epithelia orient their mitotic spindles in the plane of the epithelium so that both daughter cells are born within the epithelial sheet. This is assumed to be important to maintain epithelial integrity and prevent hyperplasia, because misaligned divisions give rise to cells outside the epithelium1,2. Here we test this assumption in three types of Drosophila epithelia; the cuboidal follicle epithelium, the columnar early embryonic ectoderm, and the pseudostratified neuroepithelium. Ectopic expression of Inscuteable in these tissues reorients mitotic spindles, resulting in one daughter cell being born outside of the epithelial layer. Live imaging reveals that these misplaced cells reintegrate into the tissue. Reducing the levels of the lateral homophilic adhesion molecules Neuroglian or Fasciclin 2 disrupts reintegration, giving rise to extra-epithelial cells, whereas disruption of adherens junctions has no effect. Thus, the reinsertion of misplaced cells appears to be driven by lateral adhesion, which pulls cells born outside the epithelia layer back into it. Our findings reveal a robust mechanism that protects epithelia against the consequences of misoriented divisions. PMID:26414404

Fluorescence lifetime microscopy for monitoring cell adhesion using metal induced energy transfer

NASA Astrophysics Data System (ADS)

Hwang, Wonsang; Seo, JinWon; Song, Jun ho; Kim, DongEun; Won, YoungJae; Choi, In-Hong; Yoo, Kyung-Hwa; Kim, Dug Young

2018-02-01

A precise control and a reliable monitoring tool for the adhesion properties of a cell are very important in atherosclerosis studies. If endothelial cells in contact with the intracellular membrane are not attached securely, low-density lipoprotein (LDL) particles can enter into the inner membrane. It is therefore necessary to measure conditions under which endothelial cell detachment occurs. When a cell is attached to a metal thin film, the lifetime of a fluorescence probe attached to the membrane of the cell is reduced by the metal-induced energy transfer (MIET). Fluorescence lifetime imaging microscopy (FLIM) is used to monitor the attachment condition of a cell to a metal surface using FRET. However, this requires high numerical aperture (NA) objective lens because axial confocal resolution must be smaller than the cell thickness. This requirement limits the field of view of the measurement specimen. In this study we provides a new method which can measure adhesion properties of endothelial cells even with a low NA objective lens by resolving two lifetime components in FLIM.

Matrix stiffness modulates infection of endothelial cells by Listeria monocytogenes via expression of cell surface vimentin.

PubMed

Bastounis, Effie E; Yeh, Yi-Ting; Theriot, Julie A

2018-05-02

Extracellular matrix stiffness (ECM) is one of the many mechanical forces acting on mammalian adherent cells and an important determinant of cellular function. While the effect of ECM stiffness on many aspects of cellular behavior has been previously studied, how ECM stiffness might mediate susceptibility of host cells to infection by bacterial pathogens was hitherto unexplored. To address this open question, we manufactured hydrogels of varying physiologically-relevant stiffness and seeded human microvascular endothelial cells (HMEC-1) on them. We then infected HMEC-1 with the bacterial pathogen Listeria monocytogenes (Lm), and found that adhesion of Lm onto host cells increases monotonically with increasing matrix stiffness, an effect that requires the activity of focal adhesion kinase (FAK). We identified cell surface vimentin as a candidate surface receptor mediating stiffness-dependent adhesion of Lm to HMEC-1 and found that bacterial infection of these host cells is decreased when the amount of surface vimentin is reduced. Our results provide the first evidence that ECM stiffness can mediate the susceptibility of mammalian host cells to infection by a bacterial pathogen.

[Effect of haw leaf extract and its preparation on polymorphonuclear leucocyte adhesion during HUVEC anoxia/reoxygenation injury].

PubMed

Li, Peng; Fu, Jian-hua; Li, Xin-zhi

2008-08-01

To study the effect and molecular mechanism of two haw leaf extracts, Vitexin-rhamnoside (VR) and Vitexin-glucoside (VG), and their preparation, Aoshaen injection (AI), on the polymorphonuclear leucocyte (PMN) adhesion during human umbilical vein endothelial cell (HUVEC) anoxia/reoxygenation (A/R) injury. The cell model of A/R injury duplicated by breaking off the oxygen supplying of HUVEC for 60 min followed with reoxygenating for 30 min (phase 1) or 240 min (phase 2) was taken as the experimental objective. The effects of testing drugs (VR, VG and AI) on PMN adhesion in the model cells were measured by enzyme immunoassay, and their effects on PMN superficial adhesion molecule CD11/CD18 expression were measured by flow cytometer respectively. After 60 min of anoxia, HUVEC was shrunk and deformed. The adhesion between PMN and HUVEC significantly revealed at phase 1 in the model group, but it was fewer in the normal cell group, and also lesser in the groups treated with various drugs. The condition of cell adhesion revealed at phase 2 was the similar to that at phase 1. All testing drugs, VR, VG and AI, showed inhibitory effect on the cell adhesion at either phase 1 or phase 2, showing a certain dose-effect relationship. The expression of CD11/ CD18 was also inhibited by the testing drugs, and a good dose-effect relation was shown by VG and AI. At the resting condition, there are almost no expression of CD11/CD18 molecule, but it could be enhanced by incubating PMN with supernate of A/R injured HUVEC culture, and more marked at phase 1. Adding the test drugs into the supernate could inhibit the enhancing of CD11/CD18 molecule expression and reduce the PMN-HUVEC adhesion, which may be one of the molecular mechanisms of haw leaf extracts and their preparation in protecting heart against A/R injury.

3-Hydroxyflavone inhibits human osteosarcoma U2OS and 143B cells metastasis by affecting EMT and repressing u-PA/MMP-2 via FAK-Src to MEK/ERK and RhoA/MLC2 pathways and reduces 143B tumor growth in vivo.

PubMed

Lu, Ko-Hsiu; Chen, Pei-Ni; Hsieh, Yi-Hsien; Lin, Chin-Yin; Cheng, Fu-Yuan; Chiu, Peng-Chou; Chu, Shu-Chen; Hsieh, Yih-Shou

2016-11-01

Many natural flavonoids have cytostatic and apoptotic properties; however, we little know whether the effect of synthetic 3-hydroxyflavone on metastasis and tumor growth of human osteosarcoma. Here, we tested the hypothesis that 3-hydroxyflavone suppresses human osteosarcoma cells metastasis and tumor growth. 3-hydroxyflavone, up to 50 μM without cytotoxicity, inhibited U2OS and 143B cells motility, invasiveness and migration by reducing matrix metalloproteinase (MMP)-2 and urokinase-type plasminogen activator (u-PA) and also impaired cell adhesion to gelatin. 3-hydroxyflavone significantly reduced p-focal adhesion kinase (FAK) Tyr397, p-FAK Tyr925, p-steroid receptor coactivator (Src), p-mitogen/extracellular signal-regulated kinase (MEK)1/2, p-myosin light chain (MLC)2 Ser19, epithelial cell adhesion molecule, Ras homolog gene family (Rho)A and fibronectin expressions. 3-hydroxyflavone also affected the epithelial-mesenchymal transition (EMT) by down-regulating expressions of Vimentin and α-catenin with activation of the transcription factor Slug. In nude mice xenograft model and tail vein injection model showed that 3-hydroxyflavone reduced 143B tumor growth and lung metastasis. 3-hydroxyflavone possesses the anti-metastatic activity of U2OS and 143B cells by affecting EMT and repressing u-PA/MMP-2 via FAK-Src to MEK/ERK and RhoA/MLC2 pathways and suppresses 143B tumor growth in vivo. This may lead to clinical trials of osteosarcoma chemotherapy to confirm the promising result in the future. Copyright © 2016 Elsevier Ltd. All rights reserved.

Vesicle-associated membrane protein 2 mediates trafficking of {alpha}5{beta}1 integrin to the plasma membrane

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hasan, Nazarul; Hu, Chuan, E-mail: chuan.hu@louisville.edu

2010-01-01

Integrins are major receptors for cell adhesion to the extracellular matrix (ECM). As transmembrane proteins, the levels of integrins at the plasma membrane or the cell surface are ultimately determined by the balance between two vesicle trafficking events: endocytosis of integrins at the plasma membrane and exocytosis of the vesicles that transport integrins. Here, we report that vesicle-associated membrane protein 2 (VAMP2), a SNARE protein that mediates vesicle fusion with the plasma membrane, is involved in the trafficking of {alpha}5{beta}1 integrin. VAMP2 was present on vesicles containing endocytosed {beta}1 integrin. Small interfering RNA (siRNA) silencing of VAMP2 markedly reduced cellmore » surface {alpha}5{beta}1 and inhibited cell adhesion and chemotactic migration to fibronectin, the ECM ligand of {alpha}5{beta}1, without altering cell surface expression of {alpha}2{beta}1 integrin or {alpha}3{beta}1 integrin. By contrast, silencing of VAMP8, another SNARE protein, had no effect on cell surface expression of the integrins or cell adhesion to fibronectin. In addition, VAMP2-mediated trafficking is involved in cell adhesion to collagen but not to laminin. Consistent with disruption of integrin functions in cell proliferation and survival, VAMP2 silencing diminished proliferation and triggered apoptosis. Collectively, these data indicate that VAMP2 mediates the trafficking of {alpha}5{beta}1 integrin to the plasma membrane and VAMP2-dependent integrin trafficking is critical in cell adhesion, migration and survival.« less

Epithelial self-healing is recapitulated by a 3D biomimetic E-cadherin junction

PubMed Central

Cohen, Daniel J.; Gloerich, Martijn; Nelson, W. James

2016-01-01

Epithelial monolayers undergo self-healing when wounded. During healing, cells collectively migrate into the wound site, and the converging tissue fronts collide and form a stable interface. To heal, migrating tissues must form cell–cell adhesions and reorganize from the front-rear polarity characteristic of cell migration to the apical-basal polarity of an epithelium. However, identifying the "stop signal" that induces colliding tissues to cease migrating and heal remains an open question. Epithelial cells form integrin-based adhesions to the basal extracellular matrix (ECM) and E-cadherin–mediated cell–cell adhesions on the orthogonal, lateral surfaces between cells. Current biological tools have been unable to probe this multicellular 3D interface to determine the stop signal. We addressed this problem by developing a unique biointerface that mimicked the 3D organization of epithelial cell adhesions. This "minimal tissue mimic" (MTM) comprised a basal ECM substrate and a vertical surface coated with purified extracellular domain of E-cadherin, and was designed for collision with the healing edge of an epithelial monolayer. Three-dimensional imaging showed that adhesions formed between cells, and the E-cadherin-coated MTM resembled the morphology and dynamics of native epithelial cell–cell junctions and induced the same polarity transition that occurs during epithelial self-healing. These results indicate that E-cadherin presented in the proper 3D context constitutes a minimum essential stop signal to induce self-healing. That the Ecad:Fc MTM stably integrated into an epithelial tissue and reduced migration at the interface suggests that this biointerface is a complimentary approach to existing tissue–material interfaces. PMID:27930308

Overexpression of Polygalacturonase in Transgenic Apple Trees Leads to a Range of Novel Phenotypes Involving Changes in Cell Adhesion1

PubMed Central

Atkinson, Ross G.; Schröder, Roswitha; Hallett, Ian C.; Cohen, Daniel; MacRae, Elspeth A.

2002-01-01

Polygalacturonases (PGs) cleave runs of unesterified GalUA that form homogalacturonan regions along the backbone of pectin. Homogalacturonan-rich pectin is commonly found in the middle lamella region of the wall where two adjacent cells abut and its integrity is important for cell adhesion. Transgenic apple (Malus domestica Borkh. cv Royal Gala) trees were produced that contained additional copies of a fruit-specific apple PG gene under a constitutive promoter. In contrast to previous studies in transgenic tobacco (Nicotiana tabacum) where PG overexpression had no effect on the plant (K.W. Osteryoung, K. Toenjes, B. Hall, V. Winkler, A.B. Bennett [1990] Plant Cell 2: 1239–1248), PG overexpression in transgenic apple led to a range of novel phenotypes. These phenotypes included silvery colored leaves and premature leaf shedding due to reduced cell adhesion in leaf abscission zones. Mature leaves had malformed and malfunctioning stomata that perturbed water relations and contributed to a brittle leaf phenotype. Chemical and ultrastructural analyses were used to relate the phenotypic changes to pectin changes in the leaf cell walls. The modification of apple trees by a single PG gene has offered a new and unexpected perspective on the role of pectin and cell wall adhesion in leaf morphology and stomatal development. PMID:12011344

The chemokine SDF-1 activates the integrins LFA-1, VLA-4, and VLA-5 on immature human CD34(+) cells: role in transendothelial/stromal migration and engraftment of NOD/SCID mice.

PubMed

Peled, A; Kollet, O; Ponomaryov, T; Petit, I; Franitza, S; Grabovsky, V; Slav, M M; Nagler, A; Lider, O; Alon, R; Zipori, D; Lapidot, T

2000-06-01

Hematopoietic stem cell homing and engraftment require several adhesion interactions, which are not fully understood. Engraftment of nonobese/severe combined immunodeficiency (NOD/SCID) mice by human stem cells is dependent on the major integrins very late activation antigen-4 (VLA-4); VLA-5; and to a lesser degree, lymphocyte function associated antigen-1 (LFA-1). Treatment of human CD34(+) cells with antibodies to either VLA-4 or VLA-5 prevented engraftment, and treatment with anti-LFA-1 antibodies significantly reduced the levels of engraftment. Activation of CD34(+) cells, which bear the chemokine receptor CXCR4, with stromal derived factor 1 (SDF-1) led to firm adhesion and transendothelial migration, which was dependent on LFA-1/ICAM-1 (intracellular adhesion molecule-1) and VLA-4/VCAM-1 (vascular adhesion molecule-1). Furthermore, SDF-1-induced polarization and extravasation of CD34(+)/CXCR4(+) cells through the extracellular matrix underlining the endothelium was dependent on both VLA-4 and VLA-5. Our results demonstrate that repopulating human stem cells functionally express LFA-1, VLA-4, and VLA-5. Furthermore, this study implies a novel approach to further advance clinical transplantation.

Mapping cell surface adhesion by rotation tracking and adhesion footprinting

NASA Astrophysics Data System (ADS)

Li, Isaac T. S.; Ha, Taekjip; Chemla, Yann R.

2017-03-01

Rolling adhesion, in which cells passively roll along surfaces under shear flow, is a critical process involved in inflammatory responses and cancer metastasis. Surface adhesion properties regulated by adhesion receptors and membrane tethers are critical in understanding cell rolling behavior. Locally, adhesion molecules are distributed at the tips of membrane tethers. However, how functional adhesion properties are globally distributed on the individual cell’s surface is unknown. Here, we developed a label-free technique to determine the spatial distribution of adhesive properties on rolling cell surfaces. Using dark-field imaging and particle tracking, we extract the rotational motion of individual rolling cells. The rotational information allows us to construct an adhesion map along the contact circumference of a single cell. To complement this approach, we also developed a fluorescent adhesion footprint assay to record the molecular adhesion events from cell rolling. Applying the combination of the two methods on human promyelocytic leukemia cells, our results surprisingly reveal that adhesion is non-uniformly distributed in patches on the cell surfaces. Our label-free adhesion mapping methods are applicable to the variety of cell types that undergo rolling adhesion and provide a quantitative picture of cell surface adhesion at the functional and molecular level.

Endothelial cells of extremely premature infants display impaired immune response after proinflammatory stimulation.

PubMed

Wisgrill, Lukas; Muck, Martina; Wessely, Isabelle; Berger, Angelika; Spittler, Andreas; Förster-Waldl, Elisabeth; Sadeghi, Kambis

2018-01-01

BackgroundEndothelial cells (ECs) exert immunological functions such as production of proinflammatory cytokines/chemokines as well as facilitation of extravasation of immune cells into infected tissue. Limited data are available on the functionality of ECs from extremely preterm neonates during infection. Accordingly, the aim of our study was to investigate the immune response of premature ECs after proinflammatory stimulation.MethodsCell adhesion receptors' expression and function, nuclear factor 'kappa-light-chain-enhancer' of activated B-cells (NFκB) signaling, and chemokine production were analyzed in umbilical cord ECs from extremely preterm and term neonates after proinflammatory stimulation.ResultsP-selectin and E-selectin surface expression as well as NFκB signaling were lower after lipopolysaccharide (LPS) stimulation in premature ECs. Preterm ECs exhibited lower, but significant, cell-adhesive functions after LPS stimulation compared with term ECs. CCL2/CXCL8 chemokine secretion was significantly upregulated after proinflammatory stimulation in both groups. CXCL10 production was significantly increased in term but not in preterm ECs upon stimulation with tumor necrosis factor compared with unstimulated ECs.ConclusionExtremely premature ECs showed partly reduced expression levels and function of cell adhesion molecules. Both NFκB signaling and chemokine/cytokine production were reduced in premature ECs. The diminished endothelial proinflammatory immune response might result in impaired infection control of preterm newborns rendering them prone to severe infection.

Influence de revetements bioactifs sur les cellules endotheliales: Vers des protheses vasculaires non thrombotiques

NASA Astrophysics Data System (ADS)

Fadlallah, Hicham

Developing vascular prostheses of small diameter to replace vessels closed by atherosclerosis remains a challenge because of the risk of thrombosis. Seeding of endothelial cells, which have antithrombogenic properties, is a promising solution, but we must create surfaces which promote their adhesion and retention to resist shear stresses created by the blood flow on the surface. This master's project aimed at investigating the effect of a plasma polymerized coating rich in primary amines (called LP), with or without elements of the extracellular matrix (Fibronectin (FN) or chondroitin sulphate (CS)) on the endothelial cells and hemocompatibility of polyethylene terephthalate (PET). The adhesion, growth and retention of human umbilical vein endothelial cells (HUVECs) on PET and LP, in the presence and absence of FN or CS, have been studied. In addition, platelet adhesion on different surfaces was evaluated by a perfusion test with whole blood, platelets being previously labeled with rhodamine. Finally a double fluorescent labeling (using Cellview Maroon to mark the HUVECs and CD61 antibody for platelets) was developed to study the retention of endothelial cells, under blood flow and verify their non thrombogenic character. The results obtained show that both the LP coating and the adsorbed FN, strongly increase both the cellular adhesion and growth on PET; however they have no additional effect when the two are combined. They also augment cellular retention to surface, but this remains incomplete. Moreover we observed that the plasma coating (LP) greatly increases the thrombogenicity of the surface, with strong platelet adhesion and activation. This thrombogenicity is extremely reduced when endothelial cells cover the surface, but cell loss under the effect of shear produced by the perfusion creates significant areas of platelet adhesion. The grafting of CS on LP also permits good HUVECs adhesion, growth and retention under shear stress on HUVEC, with no difference from the LP alone. In addition, the CS sharply decreases the platelet adhesion, which is found below the value observed for PET. The double cell labeling also showed that cells adhered on LP+CS has an anti-thrombotic phenotype and can resist blood flow. These studies suggest that a coating of CS is a promising strategy for vascular prosthesis given the combination of the good adhesion of endothelial cells and the low thrombogenicity of the underlying surface. Keywords: vascular prostheses, polymers, bioactive coating, thrombogenicity, HUVECs.

Cell Adhesion Modification of Streptococcus viridians in the Presence of Xylitol

NASA Astrophysics Data System (ADS)

Esmacher, Jason; Vidakovich, Blair; Giangrande, Michael; Hoffmann, Peter

2012-10-01

There is scientific documentation that those who chew gum sweetened by the sugar alcohol xylitol report a dramatically lower incident of both dental caries and otitis media compared to those who chew conventional gum sweetened by sucrose. An explanation contends that xylitol interferes with the ability of Streptococcus viridian (SV) to form biofilms which is a necessary precursor to the bacteria's ability to damage human tissues. We have used atomic force microscopy to study the cell wall/fimbria properties at the nanonewton level in both the presence and absence of xylitol. The first set of measurements used varying concentrations of xylitol incorporated within the incubation medium. The second used non-xylitol grown bacteria, the xylitol was added externally at various concentrations. Our study suggests that growing SV with xylitol reduces their ability to adhere together. Additionally, externally added xylitol showed grouping of cell adhesion to a relatively narrow nanonewton spread that is concentration dependent. Measurement of the adhesion properties of the bacterial cell wall have found that there is a dramatic increase in the cell wall's firmness which simultaneously accompanied a decrease in its ability to support adhesion, even at very low concentrations of xylitol.

Antioxidant Peptides Identified from Ovotransferrin by the ORAC Method Did Not Show Anti-Inflammatory and Antioxidant Activities in Endothelial Cells.

PubMed

Jahandideh, Forough; Chakrabarti, Subhadeep; Davidge, Sandra T; Wu, Jianping

2016-01-13

Oxygen radical absorbance capacity (ORAC) is a widely used method of measuring antioxidant capacities of various antioxidant components. Surprisingly, 16 antioxidant peptides previously identified from egg protein ovotransferrin using the ORAC method did not show any anti-inflammatory and antioxidant activities in cells. After simulated gastro-intestinal digestion (GID), several peptide digests significantly reduced the expression of tumor necrosis factor-α (TNF-α)-induced pro-inflammatory intercellular cell adhesion molecule-1 (ICAM-1) by 65.7 ± 10.4% and vascular cell adhesion molecule-1 (VCAM-1) by 53.5 ± 9.6% to 61.0 ± 14.5%, but only GWNI reduced TNF-α-activated superoxide generation by 71.0 ± 12.9% when tested with dihydroethidium (DHE) assay. Mass spectrometer analysis identified two new peptides, GWN and GW, in the GWNI digest; however, only GW reduced TNF-α-induced VCAM-1 expression (64.3 ± 20.6%) significantly compared to the TNF-α treated cells. Our study suggested that ORAC lacked biological relevance in assessing bioactive peptides.

Curcumin modulates endothelial permeability and monocyte transendothelial migration by affecting endothelial cell dynamics.

PubMed

Monfoulet, Laurent-Emmanuel; Mercier, Sylvie; Bayle, Dominique; Tamaian, Radu; Barber-Chamoux, Nicolas; Morand, Christine; Milenkovic, Dragan

2017-11-01

Curcumin is a phenolic compound that exhibits beneficial properties for cardiometabolic health. We previously showed that curcumin reduced the infiltration of immune cells into the vascular wall and prevented atherosclerosis development in mice. This study aimed to investigate the effect of curcumin on monocyte adhesion and transendothelial migration (TEM) and to decipher the underlying mechanisms of these actions. Human umbilical vein endothelial cells (HUVECs) were exposed to curcumin (0.5-1μM) for 3h prior to their activation by Tumor Necrosis Factor alpha (TNF-α). Endothelial permeability, monocyte adhesion and transendothelial migration assays were conducted under static condition and shear stress that mimics blood flow. We further investigated the impact of curcumin on signaling pathways and on the expression of genes using macroarrays. Pre-exposure of endothelial cells to curcumin reduced monocyte adhesion and their transendothelial migration in both static and shear stress conditions. Curcumin also prevented changes in both endothelial permeability and the area of HUVECs when induced by TNF-α. We showed that curcumin modulated the expression of 15 genes involved in the control of cytoskeleton and endothelial junction dynamic. Finally, we showed that curcumin inhibited NF-κB signaling likely through an antagonist interplay with several kinases as suggested by molecular docking analysis. Our findings demonstrate the ability of curcumin to reduce monocyte TEM through a multimodal regulation of the endothelial cell dynamics with a potential benefit on the vascular endothelial function barrier. Copyright © 2017 Elsevier Inc. All rights reserved.

Uncovering a role for the tail of the Dictyostelium discoideum SadA protein in cell-substrate adhesion.

PubMed

Kowal, Anthony S; Chisholm, Rex L

2011-05-01

Previous work from our laboratory showed that the Dictyostelium discoideum SadA protein plays a central role in cell-substrate adhesion. SadA null cells exhibit a loss of adhesion, a disrupted actin cytoskeleton, and a cytokinesis defect. How SadA mediates these phenotypes is unknown. This work addresses the mechanism of SadA function, demonstrating an important role for the C-terminal cytoplasmic tail in SadA function. We found that a SadA tailless mutant was unable to rescue the sadA adhesion deficiency, and overexpression of the SadA tail domain reduced adhesion in wild-type cells. We also show that SadA is closely associated with the actin cytoskeleton. Mutagenesis studies suggested that four serine residues in the tail, S924/S925 and S940/S941, may regulate association of SadA with the actin cytoskeleton. Glutathione S-transferase pull-down assays identified at least one likely interaction partner of the SadA tail, cortexillin I, a known actin bundling protein. Thus, our data demonstrate an important role for the carboxy-terminal cytoplasmic tail in SadA function and strongly suggest that a phosphorylation event in this tail regulates an interaction with cortexillin I. Based on our data, we propose a model for the function of SadA.

Electrochemical Responsive Superhydrophilic Surfaces of Polythiophene Derivatives towards Cell Capture and Release.

PubMed

Hao, Yuwei; Li, Yingying; Zhang, Feilong; Cui, Haijun; Hu, Jinsong; Meng, Jingxin; Wang, Shutao

2018-03-23

Highly efficient cell capture and release with low background are urgently required for early diagnosis of diseases such as cancer. Herein, we report an electrochemical responsive superhydrophilic surface exhibiting specific cell capture and release with high yields and extremely low nonspecific adhesion. Through electrochemical deposition, 3-substituted thiophene derivatives are deposited onto indium tin oxide (ITO) nanowire arrays with 4-n-nonylbenzeneboronic acid (BA) as dopant, fabricating the electrochemical responsive superhydrophilic surfaces. The molecular recognition between sialic acids over-expressed on the cell membrane and doped BAs endows the electrochemical responsive surfaces with the ability to capture and release targeted cancer cells. By adjusting the substituent group of thiophene derivatives, the surface wettability can be readily regulated and further utilized for reducing nonspecific cell adhesion. Significantly, the released cells still maintain a high proliferation ability, which indicates that the applied potential does not significantly harm the cells. Therefore, these results may provide a new strategy to achieve advanced functions of biomedical materials, such as low nonspecific adhesion. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Pioglitazone inhibits LOX-1 expression in human coronary artery endothelial cells by reducing intracellular superoxide radical generation.

PubMed

Mehta, Jawahar L; Hu, Bo; Chen, Jiawei; Li, Dayuan

2003-12-01

LOX-1, a novel lectin-like receptor for oxidized LDL (ox-LDL), is expressed in response to ox-LDL, angiotensin II (Ang II), tumor necrosis factor (TNF)-alpha, and other stress stimuli. It is highly expressed in atherosclerotic tissues. Peroxisome proliferator-activated receptor (PPAR)-gamma ligands, such as pioglitazone, exert antiatherosclerotic effects. This study examined the regulation of LOX-1 expression in human coronary artery endothelial cells (HCAECs) by pioglitazone. Fourth generation HCAECs were treated with ox-LDL, Ang II, or TNF-alpha with or without pioglitazone pretreatment. All 3 stimuli upregulated LOX-1 expression (mRNA and protein). Pioglitazone, in a concentration-dependent manner, reduced LOX-1 expression (P<0.01 versus ox-LDL, Ang II, or TNF-alpha alone). Ox-LDL, Ang II, and TNF-alpha each enhanced intracellular superoxide radical generation, and pioglitazone pretreatment reduced superoxide generation (P<0.01 versus ox-LDL, Ang II, or TNF-alpha). Furthermore, all 3 stimuli upregulated the expression of the transcription factors nuclear factor-kappaB and activator protein-1 (determined by electrophoretic mobility shift assay), and pioglitazone pretreatment reduced this expression (P<0.01 versus ox-LDL, Ang II, or TNF-alpha). To determine the biological significance of pioglitazone-mediated downregulation of LOX-1, we studied monocyte adhesion to ox-LDL-treated HCAECs. Pioglitazone reduced the adhesion of monocytes to activated HCAECs in a fashion similar to that produced by antisense to LOX-1 mRNA. These observations suggest that the PPAR-gamma ligand pioglitazone reduces intracellular superoxide radical generation and subsequently reduces the expression of transcription factors, expression of the LOX-1 gene, and monocyte adhesion to activated endothelium. The salutary effect of PPAR-gamma ligands in atherogenesis may involve the inhibition of LOX-1 and the adhesion of monocytes to endothelium.

The interactions between CdSe quantum dots and yeast Saccharomyces cerevisiae: adhesion of quantum dots to the cell surface and the protection effect of ZnS shell.

PubMed

Mei, Jie; Yang, Li-Yun; Lai, Lu; Xu, Zi-Qiang; Wang, Can; Zhao, Jie; Jin, Jian-Cheng; Jiang, Feng-Lei; Liu, Yi

2014-10-01

The interactions between quantum dots (QDs) and biological systems have attracted increasing attention due to concerns on possible toxicity of the nanoscale materials. The biological effects of CdSe QDs and CdSe/ZnS QDs with nearly identical hydrodynamic size on Saccharomyces cerevisiae were investigated via microcalorimetric, spectroscopic and microscopic methods, demonstrating a toxic order CdSe>CdSe/ZnS QDs. CdSe QDs damaged yeast cell wall and reduced the mitochondrial membrane potential. Noteworthy, adhesion of QDs to the yeast cell surface renders this work a good example of interaction site at cell surface, and the epitaxial coating of ZnS could greatly reduce the toxicity of Cd-containing QDs. These results will contribute to the safety evaluation of quantum dots, and provide valuable information for design of nanomaterials. Copyright © 2014 Elsevier Ltd. All rights reserved.

E-selectin ligand-1 controls circulating prostate cancer cell rolling/adhesion and metastasis

PubMed Central

Yasmin-Karim, Sayeda; King, Michael R.; Messing, Edward M.; Lee, Yi-Fen

2014-01-01

Circulating prostate cancer (PCa) cells preferentially roll and adhere on bone marrow vascular endothelial cells, where abundant E-selectin and stromal cell-derived factor 1 (SDF-1) are expressed, subsequently initiating a cascade of activation events that eventually lead to the development of metastases. To elucidate the roles of circulating PCa cells' rolling and adhesion behaviors in cancer metastases, we applied a dynamic cylindrical flow-based microchannel device that is coated with E-selectin and SDF-1, mimicking capillary endothelium. Using this device we captured a small fraction of rolling PCa cells. These rolling cells display higher static adhesion ability, more aggressive cancer phenotypes and stem-like properties. Importantly, mice received rolling PCa cells, but not floating PCa cells, developed cancer metastases. Genes coding for E-selectin ligands and genes associated with cancer stem cells and metastasis were elevated in rolling PCa cells. Knock down of E-selectin ligand 1(ESL-1), significantly impaired PCa cells' rolling capacity and reduced cancer aggressiveness. Moreover, ESL-1 activates RAS and MAP kinase signal cascade, consequently inducing the downstream targets. In summary, circulating PCa cells' rolling capacity contributes to PCa metastasis, and that is in part controlled by ESL-1. PMID:25301730

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

PubMed Central

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

2018-01-01

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

Experimental evidence of Migfilin as a new therapeutic target of hepatocellular carcinoma metastasis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gkretsi, Vasiliki, E-mail: vasso.gkretsi@gmail.com; Bogdanos, Dimitrios P.; Department of Rheumatology, School of Medicine, University of Thessaly, University Hospital of Larissa, 41110 Larissa

Migfilin is a novel cell–matrix adhesion protein known to interact with Vasodilator Stimulated Phosphoprotein (VASP) and be localized both at cell–matrix and cell–cell adhesions. To date there is nothing known about its role in hepatocellular carcinoma (HCC). As matrix is important in metastasis, we aimed to investigate the Migfilin's role in HCC metastasis using two human HCC cell lines that differ in their metastatic potential; non-invasive Alexander cells and the highly invasive HepG2 cells. We silenced Migfilin by siRNA and studied its effect on signaling and metastasis-related cellular properties. We show that Migfilin's expression is elevated in HepG2 cells andmore » its silencing leads to upregulation of actin reorganization-related proteins, namely phosphor-VASP (Ser157 and Ser239), Fascin-1 and Rho-kinase-1, promoting actin polymerization and inhibiting cell invasion. Phosphor-Akt (Ser473) is decreased contributing to the upregulation of free and phosphor-β-catenin (Ser33/37Thr41) and inducing proliferation. Migfilin elimination upregulates Extracellular Signal–regulated kinase, which increases cell adhesion in HepG2 and reduces invasiveness. This is the first study to reveal that Migfilin inhibition can halt HCC metastasis in vitro, providing the molecular mechanism involved and presenting Migfilin as potential therapeutic target against HCC metastasis. - Highlights: • Migfilin is a cell–matrix and cell–cell adhesion protein known to interact with VASP. • Nothing is known about Migfilin's role in hepatocellular carcinoma (HCC). • We eliminated Migfilin from 2 HCC cell lines and studied in vitro metastasis. • Its silencing inhibits cell invasion and promotes adhesion in HepG2 invasive cells. • We provide molecular mechanism by which Migfilin elimination halts HCC metastasis.« less

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

PubMed

Khalili, Amelia Ahmad; Ahmad, Mohd Ridzuan

2015-08-05

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

A Review of Cell Adhesion Studies for Biomedical and Biological Applications

PubMed Central

Ahmad Khalili, Amelia; Ahmad, Mohd Ridzuan

2015-01-01

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

Vinculin tension distributions of individual stress fibers within cell–matrix adhesions

PubMed Central

Chang, Ching-Wei; Kumar, Sanjay

2013-01-01

Summary Actomyosin stress fibers (SFs) enable cells to exert traction on planar extracellular matrices (ECMs) by tensing focal adhesions (FAs) at the cell–ECM interface. Although it is widely appreciated that the spatial and temporal distribution of these tensile forces play key roles in polarity, motility, fate choice, and other defining cell behaviors, virtually nothing is known about how an individual SF quantitatively contributes to tensile loads borne by specific molecules within associated FAs. We address this key open question by using femtosecond laser ablation to sever single SFs in cells while tracking tension across vinculin using a molecular optical sensor. We show that disruption of a single SF reduces tension across vinculin in FAs located throughout the cell, with enriched vinculin tension reduction in FAs oriented parallel to the targeted SF. Remarkably, however, some subpopulations of FAs exhibit enhanced vinculin tension upon SF irradiation and undergo dramatic, unexpected transitions between tension-enhanced and tension-reduced states. These changes depend strongly on the location of the severed SF, consistent with our earlier finding that different SF pools are regulated by distinct myosin activators. We critically discuss the extent to which these measurements can be interpreted in terms of whole-FA tension and traction and propose a model that relates SF tension to adhesive loads and cell shape stability. These studies represent the most direct and high-resolution intracellular measurements of SF contributions to tension on specific FA proteins to date and offer a new paradigm for investigating regulation of adhesive complexes by cytoskeletal force. PMID:23687380

Collisions of deformable cells lead to collective migration

NASA Astrophysics Data System (ADS)

Aranson, Igor; Löber, Jakob; Ziebert, Falko

2015-03-01

Collective migration of eukaryotic cells plays a fundamental role in tissue growth, wound healing and immune response. The motion, arising spontaneously or in response to chemical and mechanical stimuli, is also important for understanding life-threatening pathologies, such as cancer and metastasis formation. We present a phase-field model to describe the movement of many self-organized, interacting cells. The model takes into account the main mechanisms of cell motility - actomyosin dynamics, as well as substrate-mediated and cell-cell adhesion. It predicts that collective cell migration emerges spontaneously as a result of inelastic collisions between neighboring cells: collisions lead to a mutual alignment of the cell velocities and to the formation of coherently-moving multi-cellular clusters. Small cell-to-cell adhesion, in turn, reduces the propensity for large-scale collective migration, while higher adhesion leads to the formation of moving bands. Our study provides valuable insight into biological processes associated with collective cell motility. J. L. acknowledges funding from the German Science Foundation (DFG) within the GRK 1558. F. Z. acknowledges funding from the German Science Foundation (DFG) via Project ZI 1232/2-1. I. S. A. was supported by the US Department of Energy (DOE), Office of.

Tumor necrosis factor α (TNF-α) receptor-II is required for TNF-α–induced leukocyte-endothelial interaction in vivo

PubMed Central

Chandrasekharan, Unni M.; Siemionow, Maria; Unsal, Murat; Yang, Lin; Poptic, Earl; Bohn, Justin; Ozer, Kagan; Zhou, Zhongmin; Howe, Philip H.; Penn, Marc

2007-01-01

Tumor necrosis factor-α (TNF-α) binds to 2 distinct cell-surface receptors: TNF-α receptor-I (TNFR-I: p55) and TNF-α receptor-II (TNFR-II: p75). TNF-α induces leukocyte adhesion molecules on endothelial cells (ECs), which mediate 3 defined steps of the inflammatory response; namely, leukocyte rolling, firm adhesion, and transmigration. In this study, we have investigated the role of p75 in TNF-α–induced leukocyte adhesion molecules using cultured ECs derived from wild-type (WT), p75-null (p75−/−), or p55-null (p55−/−) mice. We observed that p75 was essential for TNF-α–induced E-selectin, vascular cell adhesion molecule 1 (VCAM-1), and intercellular adhesion molecule 1 (ICAM-1) expression. We also investigated the putative role of p75 in inflammation in vivo using an intravital microscopic approach with a mouse cremaster muscle model. TNF-α–stimulated leukocyte rolling, firm adhesion to ECs, and transmigration were dramatically reduced in p75−/− mice. Transplanted WT cremaster in p75−/− mice showed a robust leukocyte rolling and firm adhesion upon TNF-α activation, suggesting that the impairment in EC-leukocyte interaction in p75−/− mice is due to EC dysfunction. These results demonstrate, for the first time, that endothelial p75 is essential for TNF-α–induced leukocyte–endothelial-cell interaction. Our findings may contribute to the identification of novel p75-targeted therapeutic approaches for inflammatory diseases. PMID:17068152

In vitro Flow Adhesion Assay for Analyzing Shear-resistant Adhesion of Metastatic Cancer Cells to Endothelial Cells.

PubMed

Kang, Shin-Ae; Bajana, Sandra; Tanaka, Takemi

2016-02-20

Hematogenous metastasis is a primary cause of mortality from metastatic cancer. The shear-resistant adhesion of circulating tumor cells to the vascular endothelial cell surface under blood flow is an essential step in cell extravasation and further tissue invasion. This is similar to a process exploited by leukocytes for adhesion to inflamed blood vessels (leukocyte mimicry). The shear resistant adhesion is mediated by high affinity interactions between endothelial adhesion molecules and their counter receptor ligand expressed on circulating cells. Thus, weak interaction results in a rapid detachment of circulating cells from endothelium. Despite the critical role of vascular adhesion of cancer cells in hematogenous metastasis, our knowledge regarding this process has been limited due to the difficulty of mimicking dynamic flow conditions in vitro . In order to gain better insight into the shear-resistant adhesion of cancer cells to the endothelium, we developed a protocol for measuring the shear resistant adhesion of circulating tumor cells to endothelial cells under physiologic flow conditions by adapting a well established flow adhesion assay for inflammatory cells. This technique is useful to evaluate 1) the shear resistant adhesion competency of cancer cells and 2) the endothelial adhesion molecules necessary to support cancer cell adhesion (Kang et al. , 2015).

Motility and Adhesiveness in Human Neutrophils

PubMed Central

Smith, C. Wayne; Hollers, James C.; Patrick, Richard A.; Hassett, Clare

1979-01-01

Human peripheral blood neutrophils (PMN) obtained from healthy adults were examined in vitro with techniques adapted to assess the effects of chemotactic factors (CF) on cellular configuration and adhesiveness. The results were compared with those that use certain conventional techniques for assessing chemotaxis and chemokinesis. Exposure of PMN to N-formyl-l-methionyl-l-phenylalanine (f-Met-Phe), zymosan-activated serum, bacterial chemotactic factor, or a low molecular weight chemotactic factor from activated serum (C5a) in the absence of a gradient resulted in a change in cellular shape from a spherical to a polarized configuration in a high percentage of cells. This occurred rapidly in suspension, under conditions designed to exclude a role for cell adhesiveness, and was reversible upon removal of the CF. Restimulation of cells with the CF resulted in reappearance of the polarized configuration to the same extent as on initial stimulation with one exception: f-Met-Phe pretreated cells failed to respond to f-Met-Phe, though they responded fully to the other CF. Each CF caused a significant increase in PMN attachment to protein-coated glass. This enhanced adhesiveness was not reversible upon removal of the CF when the cells were treated under conditions shown to produce chemotactic deactivation. Cells treated under these conditions also exhibited significantly reduced motility on glass and in micropore filters in the absence of a gradient of CF. Bacterial chemotactic factor, even at high concentrations, failed to produce deactivation and did not cause a sustained enhancement of adhesiveness. Images PMID:372238

Effect of tributyltin on mammalian endothelial cell integrity.

PubMed

Botelho, G; Bernardini, C; Zannoni, A; Ventrella, V; Bacci, M L; Forni, M

2015-01-01

Tributyltin (TBT), is a man-made pollutants, known to accumulate along the food chain, acting as an endocrine disruptor in marine organisms, with toxic and adverse effects in many tissues including vascular system. Based on the absence of specific studies of TBT effects on endothelial cells, we aimed to evaluate the toxicity of TBT on primary culture of porcine aortic endothelial cells (pAECs), pig being an excellent model to study human cardiovascular disease. pAECs were exposed for 24h to TBT (100, 250, 500, 750 and 1000nM) showing a dose dependent decrease in cell viability through both apoptosis and necrosis. Moreover the ability of TBT (100 and 500nM) to influence endothelial gene expression was investigated at 1, 7 and 15h of treatment. Gene expression of tight junction molecules, occludin (OCLN) and tight junction protein-1 (ZO-1) was reduced while monocyte adhesion and adhesion molecules ICAM-1 and VCAM-1 (intercellular adhesion molecule-1 and vascular cell adhesion molecule-1) levels increased significantly at 1h. IL-6 and estrogen receptors 1 and 2 (ESR-1 and ESR-2) mRNAs, after a transient decrease, reached the maximum levels after 15h of exposure. Finally, we demonstrated that TBT altered endothelial functionality greatly increasing monocyte adhesion. These findings indicate that TBT deeply alters endothelial profile, disrupting their structure and interfering with their ability to interact with molecules and other cells. Copyright © 2015 Elsevier Inc. All rights reserved.

Suppression of proatherogenic leukocyte interactions by MCS-18--Impact on advanced atherosclerosis in ApoE-deficient mice.

PubMed

Kuehn, Constanze; Tauchi, Miyuki; Stumpf, Christian; Daniel, Christoph; Bäuerle, Tobias; Schwarz, Marc; Kerek, Franz; Steinkasserer, Alexander; Zinser, Elisabeth; Achenbach, Stephan; Dietel, Barbara

2016-02-01

Atherosclerosis is associated with chronic inflammatory responses of the arterial blood vessels. The previously observed protective effect of the MCS-18 substance against the initiation of atherosclerosis in a murine model was explained by its pronounced anti-inflammatory activity. Here, we investigated its impact on murine plaque progression in advanced atherosclerosis and on proatherogenic processes. ApoE-deficient mice were fed a high-fat diet for 12 weeks to induce atherosclerosis, followed by normal chow and intraperitoneal injections of either MCS-18 (500 μg, n = 10) or saline (n = 10) twice a week for another 12 weeks. Plaque size was reduced in MCS-18 treated mice compared to controls (p = 0.001), which was associated with a reduced size of the lipid core (p = 0.01). There was a decrease in apoptotic cells (p = 0.02), endothelial ICAM-1 expression (p < 0.001), and macrophage density (p = 0.01) in the MCS-18 group. In addition, human and murine dendritic cells (DCs) and human umbilical vein endothelial cells (HUVECs) were treated with MCS-18 (50-200 μg/ml) to analyze cell migration and adhesion under flow conditions. MCS-18 reduced human (p = 0.01) and murine (p = 0.006) DC migration. Furthermore, adhesion of MCS-18-treated DCs to a HUVEC monolayer was decreased (p < 0.001). Compared to controls, CD209 (p < 0.001) and CCR7 (p = 0.003) expression was decreased in MCS-18-treated DCs, while in HUVECs lower levels of ICAM-1 (p < 0.001) and of phosphorylated NF-κB-p65 (p = 0.002) were observed. Blocking of ICAM-1 reduced DC adhesion (p < 0.001). MCS-18 exhibits interesting therapeutic effects when applied in advanced murine atherosclerosis. Its antiatherogenic impact might be associated with a suppressed adhesion to the endothelium due to down-regulation of endothelial ICAM-1 expression. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

αMβ2-integrin-intercellular adhesion molecule-1 interactions drive the flow-dependent trafficking of Guillain-Barré syndrome patient derived mononuclear leukocytes at the blood-nerve barrier in vitro

PubMed Central

Yosef, Nejla; Ubogu, Eroboghene E.

2012-01-01

The mechanisms of hematogenous leukocyte trafficking at the human blood-nerve barrier (BNB) are largely unknown. Intercellular adhesion molecule-1 (ICAM-1) has been implicated in the pathogenesis of Guillain-Barré syndrome (GBS). We developed a cytokine-activated human in vitro BNB model using primary endoneurial endothelial cells. Endothelial treatment with 10 U/mL tissue necrosis factor-α and 20 U/mL interferon-γ resulted in de novo expression of proinflammatory chemokines CCL2, CXCL9, CXCL11 and CCL20, with increased expression of CXCL2-3, CXCL8 and CXCL10 relative to basal levels. Cytokine treatment induced/ enhanced ICAM-1, E- and P-selectin, vascular cell adhesion molecule-1 and the alternatively spliced pro-adhesive fibronectin variant, fibronectin connecting segment-1 expression in a time-dependent manner, without alterations in junctional adhesion molecule-A expression. Lymphocytes and monocytes from untreated GBS patients express ICAM-1 counterligands, αM- and αL-integrin, with differential regulation of αM-integrin expression compared to healthy controls. Under flow conditions that mimic capillary hemodynamics in vivo, there was a >3-fold increase in total GBS patient and healthy control mononuclear leukocyte adhesion/ migration at the BNB following cytokine treatment relative to the untreated state. Function neutralizing monoclonal antibodies against human αM-integrin (CD11b) and ICAM-1 reduced untreated GBS patient mononuclear leukocyte trafficking at the BNB by 59% and 64.2% respectively. Monoclonal antibodies against αL-integrin (CD11a) and human intravenous immunoglobulin reduced total leukocyte adhesion/migration by 22.8% and 17.6% respectively. This study demonstrates differential regulation of αM-integrin on circulating mononuclear cells in GBS, as well as an important role for αM-integrin-ICAM-1 interactions in pathogenic GBS patient leukocyte trafficking at the human BNB in vitro. PMID:22552879

Vasostatin-2 inhibits cell proliferation and adhesion in vascular smooth muscle cells, which are associated with the progression of atherosclerosis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hou, Jianghong, E-mail: jianghonghou@163.com; Xue, Xiaolin; Li, Junnong

2016-01-22

Recently, the serum expression level of vasostatin-2 was found to be reduced and is being studied as an important indicator to assess the presence and severity of coronary artery disease; the functional properties of vasostatin-2 and its relationship with the development of atherosclerosis remains unclear. In this study, we attempted to detect the expression of vasostatin-2 and its impact on human vascular smooth muscle cells (VSMCs). Quantitative real-time PCR (qRT-PCR) and western blot were used to assess the expression level of vasostatin-2 in VSMCs between those from atherosclerosis and disease-free donors; we found that vasostatin-2 was significantly down-regulated in atherosclerosismore » patient tissues and cell lines. In addition, the over-expression of vasostatin-2 apparently inhibits cell proliferation and migration in VSMCs. Gain-of-function in vitro experiments further show that vasostatin-2 over-expression significantly inhibits inflammatory cytokines release in VSMCs. In addition, cell adhesion experimental analysis showed that soluble adhesion molecules (sICAM-1, sVCAM-1) had decreased expression when vasostatin-2 was over-expressed in VSMCs. Therefore, our results indicate that vasostatin-2 is an atherosclerosis-related factor that can inhibit cell proliferation, inflammatory response and cell adhesion in VSMCs. Taken together, our results indicate that vasostatin-2 could serve as a potential diagnostic biomarker and therapeutic option for human atherosclerosis in the near future. - Highlights: • Vasostatin-2 levels were down-regulated in atherosclerosis patient tissues and VSMCs. • Ectopic expression of vasostatin-2 directly affects cell proliferation and migration in vitro. • Ectopic expression of vasostatin-2 protein affects pro-inflammatory cytokines release in VSMCs. • Ectopic expression of vasostatin-2 protein affects cell adhesion in VSMCs.« less

FABP4 regulates eosinophil recruitment and activation in allergic airway inflammation.

PubMed

Ge, Xiao Na; Bastan, Idil; Dileepan, Mythili; Greenberg, Yana; Ha, Sung Gil; Steen, Kaylee A; Bernlohr, David A; Rao, Savita P; Sriramarao, P

2018-04-26

Fatty acid binding protein 4 (FABP4), a member of a family of lipid-binding proteins, is known to play a role in inflammation by virtue of its ability to regulate intracellular events such as lipid fluxes and signaling. Studies have indicated a pro-inflammatory role for FABP4 in allergic asthma, although its expression and function in eosinophils, the predominant inflammatory cells recruited to allergic airways, was not investigated. We examined expression of FABP4 in murine eosinophils and its role in regulating cell recruitment in vitro as well as in cockroach antigen (CRA)-induced allergic airway inflammation. CRA exposure led to airway recruitment of FABP4-expressing inflammatory cells, specifically eosinophils, in wild type (WT) mice. FABP4 expression in eosinophils was induced by TNF-α as well as IL-4 and IL-13. FABP4-deficient eosinophils exhibited markedly decreased cell spreading/formation of leading edges on vascular cell adhesion molecule-1 and significantly decreased adhesion to intercellular adhesion molecule-1 associated with reduced β2 integrin expression relative to WT cells. Further, FABP4-deficient eosinophils exhibited decreased migration, F-actin polymerization, calcium flux and ERK (1/2) phosphorylation in response to eotaxin-1. In vivo, CRA-challenged FABP4-deficient mice exhibited attenuated eosinophilia and significantly reduced airway inflammation (improved airway reactivity, lower IL-5, IL-13, TNFα and LTC4 levels, decreased airway structural changes) compared to WT mice. In conclusion, expression of FABP4 in eosinophils is induced during conditions of inflammation and plays a pro-inflammatory role in the development of allergic asthma by promoting eosinophil adhesion and migration and contributing to the development of various aspects of airway inflammation.

Annexin A8 controls leukocyte recruitment to activated endothelial cells via cell surface delivery of CD63

NASA Astrophysics Data System (ADS)

Poeter, Michaela; Brandherm, Ines; Rossaint, Jan; Rosso, Gonzalo; Shahin, Victor; Skryabin, Boris V.; Zarbock, Alexander; Gerke, Volker; Rescher, Ursula

2014-04-01

To enable leukocyte adhesion to activated endothelium, the leukocyte receptor P-selectin is released from Weibel-Palade bodies (WPB) to the endothelial cell surface where it is stabilized by CD63. Here we report that loss of annexin A8 (anxA8) in human umbilical vein endothelial cells (HUVEC) strongly decreases cell surface presentation of CD63 and P-selectin, with a concomitant reduction in leukocyte rolling and adhesion. We confirm the compromised leukocyte adhesiveness in inflammatory-activated endothelial venules of anxA8-deficient mice. We find that WPB of anxA8-deficient HUVEC contain less CD63, and that this is caused by improper transport of CD63 from late multivesicular endosomes to WPB, with CD63 being retained in intraluminal vesicles. Consequently, reduced CD63 cell surface levels are seen following WPB exocytosis, resulting in enhanced P-selectin re-internalization. Our data support a model in which anxA8 affects leukocyte recruitment to activated endothelial cells by supplying WPB with sufficient amounts of the P-selectin regulator CD63.

Pou5f1-dependent EGF expression controls E-cad endocytosis, cell adhesion, and zebrafish epiboly movements

PubMed Central

Song, Sungmin; Eckerle, Stephanie; Onichtchouk, Daria; Marrs, James A.; Nitschke, Roland; Driever, Wolfgang

2013-01-01

Summary Initiation of motile cell behavior in embryonic development occurs during late blastula stages when gastrulation begins. At this stage, the strong adhesion of blastomeres has to be modulated to enable dynamic behavior, similar to epithelial-to-mesenchymal transitions. We show that in zebrafish MZspg embryos mutant for the stem cell transcription factor Pou5f1/Oct4, which are severely delayed in the epiboly gastrulation movement, all blastomeres are defective in E-cad endosomal trafficking and E-cad accumulates at the plasma membrane. We find that Pou5f1-dependent control of EGF expression regulates endosomal E-cad trafficking. EGFR may act via modulation of p120 activity. Loss of E-cad dynamics reduces cohesion of cells in reaggregation assays. Quantitative analysis of cell behavior indicates that dynamic E-cad endosomal trafficking is required for epiboly cell movements. We hypothesize that dynamic control of E-cad trafficking is essential to effectively generate new adhesion sites when cells move relative to each other. PMID:23484854

A composite model of the human postcapillary venule for investigation of microvascular leukocyte recruitment

PubMed Central

Lauridsen, Holly M.; Pober, Jordan S.; Gonzalez, Anjelica L.

2014-01-01

Neutrophil extravasation occurs across postcapillary venules, structures composed of endothelial cells (ECs), pericytes (PCs), and basement membrane (BM). We constructed composite models of the human postcapillary venule, combining ECs with PCs or PC-deposited BM, to better study this process. Quiescent and tumor necrosis factor α (TNF-α)-activated composites demonstrated in situ-like expression of cadherins, E-selectin, intercellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1), platelet-endothelial cell adhesion molecule 1 (PECAM-1), CD99, and interleukin 8 (IL-8). After TNF-α activation, the ECs supported greater neutrophil adhesion (66.1 vs. 23.7% of input cells) and transmigration (35.1 vs. 7.20% of input cells) than did the PCs, but the composites behaved comparably (no significant difference) to ECs in both assays. TNF-α-activated EC-conditioned medium (CM) increased transmigration across the PCs, whereas TNF-α-activated PC-CM decreased transmigration across the ECs, and culturing on PC-derived BM decreased both adhesion to and transmigration across the ECs. Anti-very late antigen 4 (VLA-4; on neutrophils) inhibited adhesion to TNF-α-activated composites, but not to ECs alone. Anti-CD99 (expressed on all 3 cell types) inhibited transmigration across the composites (14.5% of control) more than across the ECs (39.0% of control), and venular shear stress reduced transmigration across the ECs (17.3% of static) more than across the composites (36.7% of static). These results provide proof of concept that our composite human EC/PC/BM venular construct can reveal new interactions in the inflammatory cascade.—Lauridsen, H. M., Pober, J. S., Gonzalez, A. L. A composite model of the human postcapillary venule for investigation of microvascular leukocyte recruitment. PMID:24297702

Soluble adhesion molecules in human cancers: sources and fates.

PubMed

van Kilsdonk, Jeroen W J; van Kempen, Léon C L T; van Muijen, Goos N P; Ruiter, Dirk J; Swart, Guido W M

2010-06-01

Adhesion molecules endow tumor cells with the necessary cell-cell contacts and cell-matrix interactions. As such, adhesion molecules are involved in cell signalling, proliferation and tumor growth. Rearrangements in the adhesion repertoire allow tumor cells to migrate, invade and form metastases. Besides these membrane-bound adhesion molecules several soluble adhesion molecules are detected in the supernatant of tumor cell lines and patient body fluids. Truncated soluble adhesion molecules can be generated by several conventional mechanisms, including alternative splicing of mRNA transcripts, chromosomal translocation, and extracellular proteolytic ectodomain shedding. Secretion of vesicles (ectosomes and exosomes) is an alternative mechanism mediating the release of full-length adhesion molecules. Soluble adhesion molecules function as modulators of cell adhesion, induce proteolytic activity and facilitate cell signalling. Additionally, adhesion molecules present on secreted vesicles might be involved in the vesicle-target cell interaction. Based on currently available data, released soluble adhesion molecules contribute to cancer progression and therefore should not be regarded as unrelated and non-functional side products of tumor progression. 2010 Elsevier GmbH. All rights reserved.

The roles of cell adhesion molecules in tumor suppression and cell migration: a new paradox.

PubMed

Moh, Mei Chung; Shen, Shali

2009-01-01

In addition to mediating cell adhesion, many cell adhesion molecules act as tumor suppressors. These proteins are capable of restricting cell growth mainly through contact inhibition. Alterations of these cell adhesion molecules are a common event in cancer. The resulting loss of cell-cell and/or cell-extracellular matrix adhesion promotes cell growth as well as tumor dissemination. Therefore, it is conventionally accepted that cell adhesion molecules that function as tumor suppressors are also involved in limiting tumor cell migration. Paradoxically, in 2005, we identified an immunoglobulin superfamily cell adhesion molecule hepaCAM that is able to suppress cancer cell growth and yet induce migration. Almost concurrently, CEACAM1 was verified to co-function as a tumor suppressor and invasion promoter. To date, the reason and mechanism responsible for this exceptional phenomenon remain unclear. Nevertheless, the emergence of these intriguing cell adhesion molecules with conflicting roles may open a new chapter to the biological significance of cell adhesion molecules.

Suppression of lysyl-tRNA synthetase, KRS, causes incomplete epithelial-mesenchymal transition and ineffective cell‑extracellular matrix adhesion for migration.

PubMed

Nam, Seo Hee; Kang, Minkyung; Ryu, Jihye; Kim, Hye-Jin; Kim, Doyeun; Kim, Dae Gyu; Kwon, Nam Hoon; Kim, Sunghoon; Lee, Jung Weon

2016-04-01

The cell-adhesion properties of cancer cells can be targeted to block cancer metastasis. Although cytosolic lysyl-tRNA synthetase (KRS) functions in protein synthesis, KRS on the plasma membrane is involved in cancer metastasis. We hypothesized that KRS is involved in cell adhesion-related signal transduction for cellular migration. To test this hypothesis, colon cancer cells with modulated KRS protein levels were analyzed for cell-cell contact and cell-substrate adhesion properties and cellular behavior. Although KRS suppression decreased expression of cell-cell adhesion molecules, cells still formed colonies without being scattered, supporting an incomplete epithelial mesenchymal transition. Noteworthy, KRS-suppressed cells still exhibited focal adhesions on laminin, with Tyr397-phopshorylated focal adhesion kinase (FAK), but they lacked laminin-adhesion-mediated extracellular signal-regulated kinase (ERK) and paxillin activation. KRS, p67LR and integrin α6β1 were found to interact, presumably to activate ERK for paxillin expression and Tyr118 phosphorylation even without involvement of FAK, so that specific inhibition of ERK or KRS in parental HCT116 cells blocked cell-cell adhesion and cell-substrate properties for focal adhesion formation and signaling activity. Together, these results indicate that KRS can promote cell-cell and cell-ECM adhesion for migration.

Cell adhesion heterogeneity reinforces tumour cell dissemination: novel insights from a mathematical model.

PubMed

Reher, David; Klink, Barbara; Deutsch, Andreas; Voss-Böhme, Anja

2017-08-11

Cancer cell invasion, dissemination, and metastasis have been linked to an epithelial-mesenchymal transition (EMT) of individual tumour cells. During EMT, adhesion molecules like E-cadherin are downregulated and the decrease of cell-cell adhesion allows tumour cells to dissociate from the primary tumour mass. This complex process depends on intracellular cues that are subject to genetic and epigenetic variability, as well as extrinsic cues from the local environment resulting in a spatial heterogeneity in the adhesive phenotype of individual tumour cells. Here, we use a novel mathematical model to study how adhesion heterogeneity, influenced by intrinsic and extrinsic factors, affects the dissemination of tumour cells from an epithelial cell population. The model is a multiscale cellular automaton that couples intracellular adhesion receptor regulation with cell-cell adhesion. Simulations of our mathematical model indicate profound effects of adhesion heterogeneity on tumour cell dissemination. In particular, we show that a large variation of intracellular adhesion receptor concentrations in a cell population reinforces cell dissemination, regardless of extrinsic cues mediated through the local cell density. However, additional control of adhesion receptor concentration through the local cell density, which can be assumed in healthy cells, weakens the effect. Furthermore, we provide evidence that adhesion heterogeneity can explain the remarkable differences in adhesion receptor concentrations of epithelial and mesenchymal phenotypes observed during EMT and might drive early dissemination of tumour cells. Our results suggest that adhesion heterogeneity may be a universal trigger to reinforce cell dissemination in epithelial cell populations. This effect can be at least partially compensated by a control of adhesion receptor regulation through neighbouring cells. Accordingly, our findings explain how both an increase in intra-tumour adhesion heterogeneity and the loss of control through the local environment can promote tumour cell dissemination. This article was reviewed by Hanspeter Herzel, Thomas Dandekar and Marek Kimmel.

GBM heterogeneity as a function of variable epidermal growth factor receptor variant III activity.

PubMed

Lindberg, Olle R; McKinney, Andrew; Engler, Jane R; Koshkakaryan, Gayane; Gong, Henry; Robinson, Aaron E; Ewald, Andrew J; Huillard, Emmanuelle; David James, C; Molinaro, Annette M; Shieh, Joseph T; Phillips, Joanna J

2016-11-29

Abnormal activation of the epidermal growth factor receptor (EGFR) due to a deletion of exons 2-7 of EGFR (EGFRvIII) is a common alteration in glioblastoma (GBM). While this alteration can drive gliomagenesis, tumors harboring EGFRvIII are heterogeneous. To investigate the role for EGFRvIII activation in tumor phenotype we used a neural progenitor cell-based murine model of GBM driven by EGFR signaling and generated tumor progenitor cells with high and low EGFRvIII activation, pEGFRHi and pEGFRLo. In vivo, ex vivo, and in vitro studies suggested a direct association between EGFRvIII activity and increased tumor cell proliferation, decreased tumor cell adhesion to the extracellular matrix, and altered progenitor cell phenotype. Time-lapse confocal imaging of tumor cells in brain slice cultures demonstrated blood vessel co-option by tumor cells and highlighted differences in invasive pattern. Inhibition of EGFR signaling in pEGFRHi promoted cell differentiation and increased cell-matrix adhesion. Conversely, increased EGFRvIII activation in pEGFRLo reduced cell-matrix adhesion. Our study using a murine model for GBM driven by a single genetic driver, suggests differences in EGFR activation contribute to tumor heterogeneity and aggressiveness.

Endogenous axon guiding chemorepulsant semaphorin-3F inhibits the growth and metastasis of colorectal carcinoma.

PubMed

Wu, Feng; Zhou, Qi; Yang, Jing; Duan, Guang-jie; Ou, Juan-juan; Zhang, Rong; Pan, Feng; Peng, Qiu-ping; Tan, Hong; Ping, Yi-fang; Cui, You-hong; Qian, Cheng; Yan, Xiao-chu; Bian, Xiu-wu

2011-05-01

To elucidate the role of Semaphorin-3F (SEMA3F), originally described as an axon guiding chemorepulsant implicated in nerve development, in the progression of colorectal carcinoma. SEMA3F and its receptor NRP2 were examined in 72 cases of human colorectal carcinoma specimens and cell lines LoVo, SW480, and SW620 with immunohistochemistry and Western blotting. SEMA3F mRNA expression in the frozen tissue specimens and cell lines was examined with quantitative reverse transcriptase-PCR. Confocal laser scanning microscopy was used for detection of cellular localization of the proteins by immunofluorescent staining. MTT assay, flow cytometry, cell adhesion and migration, and xenografts were used to evaluate biological significance of SEMA3F. SEMA3F was significantly reduced in colorectal carcinoma tissues and cell lines. Overexpression of SEMA3F resulted in reduced proliferation, adhesion to fibronectin, and migratory capability as well as reduced S-phase population and integrin αvβ3 expression of SW480 colon cancer cells. In addition, SEMA3F-overexpressing cells exhibited diminished tumorigenesis when transplanted orthotopically in nude mice and reduced liver metastases. Moreover, transfection of siRNA targeting SEMA3F in colon cancer cells increased their tumorigenicity in vivo. Endogenous SEMA3F acts as a suppressor of the growth and metastasis of human colorectal cancer cells. ©2011 AACR.

Lipid-Polymer Nanoparticles Encapsulating Curcumin for Modulating the Vascular Deposition of Breast Cancer Cells

PubMed Central

Palange, Anna L.; Di Mascolo, Daniele; Carallo, Claudio; Gnasso, Agostino; Decuzzi, Paolo

2014-01-01

Vascular adhesion and endothelial transmigration are critical steps in the establishment of distant metastasis by circulating tumor cells (CTCs). Also, vascular inflammation plays a pivotal role in steering CTCs out of the blood stream. Here, long circulating lipid-polymer nanoparticles encapsulating curcumin (NANOCurc) are proposed for modulating the vascular deposition of CTCs. Upon treatment with NANOCurc, the adhesion propensity of highly metastatic breast cancer cells (MDA-MB-231) onto TNF-α stimulated endothelial cells (HUVECs) reduces by ~ 70%, in a capillary flow. Remarkably, the CTC vascular deposition already reduces up to ~ 50% by treating solely the inflamed HUVECs. The CTC arrest is mediated by the interaction between ICAM-1 on HUVECs and MUC-1 on cancer cells, and moderate doses of curcumin down-regulate the expression of both molecules. This suggests that NANOCurc could prevent metastasis and limit the progression of the disease by modulating vascular inflammation and impairing the CTC arrest. PMID:24566270

Actin-myosin contractility is responsible for the reduced viability of dissociated human embryonic stem cells.

PubMed

Chen, Guokai; Hou, Zhonggang; Gulbranson, Daniel R; Thomson, James A

2010-08-06

Human ESCs are the pluripotent precursor of the three embryonic germ layers. Human ESCs exhibit basal-apical polarity, junctional complexes, integrin-dependent matrix adhesion, and E-cadherin-dependent cell-cell adhesion, all characteristics shared by the epiblast epithelium of the intact mammalian embryo. After disruption of epithelial structures, programmed cell death is commonly observed. If individualized human ESCs are prevented from reattaching and forming colonies, their viability is significantly reduced. Here, we show that actin-myosin contraction is a critical effector of the cell death response to human ESC dissociation. Inhibition of myosin heavy chain ATPase, downregulation of myosin heavy chain, and downregulation of myosin light chain all increase survival and cloning efficiency of individualized human ESCs. ROCK inhibition decreases phosphorylation of myosin light chain, suggesting that inhibition of actin-myosin contraction is also the mechanism through which ROCK inhibitors increase cloning efficiency of human ESCs. Copyright 2010 Elsevier Inc. All rights reserved.

[Expression of Id1 and Id3 in endometrial carcinoma and their roles in regulating biological behaviors of endometrial carcinoma cells in vitro].

PubMed

Sun, Lili; Li, Xuenong; Liu, Guobing

2013-06-01

To investigate the expression of inhibitor of DNA differentiation/DNA binding 1 (Id1) and Id3 in endometrial carcinoma and explore their roles in regulating the proliferation, invasion, migration and adhesion of endometrial carcinoma cells in vitro. Id1 and Id3 expression in 4 fresh endometrial cancer tissue specimens and matched adjacent tissues were detected using Western blotting. Two endometrial cancer cell lines, HEC-1-B and RL-952, were both divided into 4 groups, namely the untreated group, blank virus group, promoter group and Id1/Id3 double-knockdown group, and their expressions of MMP2, CXCR4 and P21 were detected by qRT-PCR and Western blotting. The proliferation, invasion, migration and adhesion of the cells were evaluated with MTT, Transwell, wound-healing, and adhesion assays. Endometrial carcinoma tissues showed significantly higher Id1 and Id3 expression than the adjacent tissues (P<0.05). In the two endometrial carcinoma cell lines, Id1/Id3 double-knockdown significantly decreased MMP2 and CXCR4 expression and increased P21 expression at both mRNA and protein levels (P<0.05), and resulted in suppressed cell proliferation, invasion, migration and adhesion. Id1 and Id3 expressions are up-regulated in endometrial carcinoma to promote the proliferation, invasion, migration and adhesion of the tumor cells by increasing MMP2 and CXCR4 expression and reducing P21 expression. Therapies targeting Id1/Id3 can be a novel strategy for treatment of endometrial carcinoma.

Complement C3 participation in monocyte adhesion to different surfaces.

PubMed Central

McNally, A K; Anderson, J M

1994-01-01

As part of an ongoing investigation into the role of the monocyte/macrophage in biocompatibility, a major goal is to identify the adhesion mechanisms that initiate and promote the observed in vivo morphologic progression of monocyte-to-macrophage-to-foreign body giant cell on biomaterials. We have exploited differently modified polystyrenes, specific component-depleted sera, and monoclonal antibodies (mAbs) to leukocyte integrins to ask what adhesion mechanisms mediate human blood monocyte adhesion to different surfaces in vitro. Preliminary findings are that monocyte interactions with fluorinated, siliconized, nitrogenated, and oxygenated surfaces are reduced by 50-100% when complement component C3-depleted serum is used for adsorption; reductions vary with material surface properties. Adhesion is restored on all surfaces when C3-depleted serum is replenished with purified C3. Monocyte adhesion to serum-adsorbed surfaces is inhibited by mAbs to the leukocyte integrin beta subunit, CD18 (mAbs 60.3 and MHM23), and partially inhibited by a mAb to the alpha subunit, CD11b (mAb 60.1), suggesting adhesive interactions between adsorbed C3bi (the hemolytically inactive form of the C3b fragment) and the leukocyte integrin CD11b/CD18. However, adsorbed fibrinogen reduces the effectiveness of these mAbs, indicating that alternative adhesion mechanisms may operate depending on the propensities of critical adhesion-mediating components to be adsorbed onto different surfaces. Images PMID:7937848

The effect of denture adhesives on Candida albicans growth in vitro.

PubMed

Sampaio-Maia, Benedita; Figueiral, Maria Helena; Sousa-Rodrigues, Patricia; Fernandes, Maria Helena; Scully, Crispian

2012-06-01

Denture-wearing favours the growth of Candida. In view of the fact that many denture wearers regularly use adhesives to enhance denture retention, stability and function, the aim of this work was to study the effect of denture adhesives on Candida albicans growth in vitro. The denture adhesives tested were Corega(®) cream, Kukident(®) cream, Novafix(®) cream, Polident(®) cream, Protefix(®) cream, Steradent(®) cream, Aderyn(®) powder, Corega(®) ultra powder, Protefix(®) powder and Corega(®) strip. C. albicans growth curves were obtained in the presence or absence of a 1% solution of the denture adhesive diluted in Sabouraud broth. Macro- and microscopic morphological changes in C. albicans were analysed, as was microbial contamination of the denture adhesive. Most of the denture adhesives studied induced morphological changes in C. albicans cells and colonies, but only two had any significant inhibitory effect on yeast growth. Kukident(®) cream markedly inhibited C. albicans growth in a concentration-dependent way, reducing the growth rate by 95%, whereas Corega(®) cream also inhibited C. albicans growth but in a non-concentration-dependent way, reducing the growth rate by 37%. In addition, denture adhesives available as powders had detectable microbial contamination. Some commercially available denture adhesives showed microbial contamination and some had significant inhibitory effect on C. albicans growth. © 2011 The Gerodontology Society and John Wiley & Sons A/S.

Actin-Based Adhesion Modules Mediate Cell Interactions with the Extracellular Matrix and Neighboring Cells.

PubMed

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

2017-07-05

Cell adhesions link cells to the extracellular matrix (ECM) and to each other and depend on interactions with the actin cytoskeleton. Both cell-ECM and cell-cell adhesion sites contain discrete, yet overlapping, functional modules. These modules establish physical associations with the actin cytoskeleton, locally modulate actin organization and dynamics, and trigger intracellular signaling pathways. Interplay between these modules generates distinct actin architectures that underlie different stages, types, and functions of cell-ECM and cell-cell adhesions. Actomyosin contractility is required to generate mature, stable adhesions, as well as to sense and translate the mechanical properties of the cellular environment into changes in cell organization and behavior. Here, we review the organization and function of different adhesion modules and how they interact with the actin cytoskeleton. We highlight the molecular mechanisms of mechanotransduction in adhesions and how adhesion molecules mediate cross talk between cell-ECM and cell-cell adhesion sites. Copyright © 2017 Cold Spring Harbor Laboratory Press; all rights reserved.

Milk Fat Globules Hamper Adhesion of Enterohemorrhagic Escherichia coli to Enterocytes: In Vitro and in Vivo Evidence

PubMed Central

Douëllou, Thomas; Galia, Wessam; Kerangart, Stéphane; Marchal, Thierry; Milhau, Nadège; Bastien, Renaud; Bouvier, Marion; Buff, Samuel; Montel, Marie-Christine; Sergentet-Thevenot, Delphine

2018-01-01

Enterohemorrhagic Escherichia coli (EHEC; E. coli) are food-borne agents associated with gastroenteritis, enterocolitis, bloody diarrhea and the hemolytic-uremic syndrome (HUS). Bovine milk glycans have been shown to contain oligosaccharides which are similar to host epithelial cell receptors and can therefore prevent bacterial adhesion. This study aimed to describe interactions between EHEC O157:H7 EDL933 and O26:H11 21765 and milk fat globules (MFGs) in raw milk and raw milk cheese, and the impact of MFGs on EHEC strains adhesion to the intestinal tract in vitro and in vivo. Both EHEC serotypes clearly associated with native bovine MFGs and significantly limited their adhesion to a co-culture of intestinal cells. The presence of MFGs in raw milk cheese had two effects on the adhesion of both EHEC serotypes to the intestinal tracts of streptomycin-treated mice. First, it delayed and reduced EHEC excretion in mouse feces for both strains. Second, the prime implantation site for both EHEC strains was 6 cm more proximal in the intestinal tracts of mice fed with contaminated cheese containing less than 5% of fat than in those fed with contaminated cheese containing 40% of fat. Feeding mice with 40% fat cheese reduced the intestinal surface contaminated with EHEC and may therefore decrease severity of illness. PMID:29867855

The Epithelial Cell Adhesion Molecule EpCAM Is Required for Epithelial Morphogenesis and Integrity during Zebrafish Epiboly and Skin Development

PubMed Central

Slanchev, Krasimir; Carney, Thomas J.; Stemmler, Marc P.; Koschorz, Birgit; Amsterdam, Adam; Schwarz, Heinz; Hammerschmidt, Matthias

2009-01-01

The aberrant expression of the transmembrane protein EpCAM is associated with tumor progression, affecting different cellular processes such as cell–cell adhesion, migration, proliferation, differentiation, signaling, and invasion. However, the in vivo function of EpCAM still remains elusive due to the lack of genetic loss-of-function studies. Here, we describe epcam (tacstd) null mutants in zebrafish. Maternal-zygotic mutants display compromised basal protrusive activity and epithelial morphogenesis in cells of the enveloping layer (EVL) during epiboly. In partial redundancy with E-cadherin (Ecad), EpCAM made by EVL cells is further required for cell–cell adhesion within the EVL and, possibly, for proper attachment of underlying deep cells to the inner surface of the EVL, thereby also affecting deep cell epiboly movements. During later development, EpCAM per se becomes indispensable for epithelial integrity within the periderm of the skin, secondarily leading to disrupted morphology of the underlying basal epidermis and moderate hyper-proliferation of skin cells. On the molecular level, EVL cells of epcam mutant embryos display reduced levels of membranous Ecad, accompanied by an enrichment of tight junction proteins and a basal extension of apical junction complexes (AJCs). Our data suggest that EpCAM acts as a partner of E-cadherin to control adhesiveness and integrity as well as plasticity and morphogenesis within simple epithelia. In addition, EpCAM is required for the interaction of the epithelia with underlying cell layers. PMID:19609345

Endothelial microparticles reduce ICAM-1 expression in a microRNA-222-dependent mechanism

PubMed Central

Jansen, Felix; Yang, Xiaoyan; Baumann, Katharina; Przybilla, David; Schmitz, Theresa; Flender, Anna; Paul, Kathrin; Alhusseiny, Adil; Nickenig, Georg; Werner, Nikos

2015-01-01

Endothelial microparticles (EMP) are released from activated or apoptotic endothelial cells (ECs) and can be taken up by adjacent ECs, but their effect on vascular inflammation after engulfment is largely unknown. We sought to determine the role of EMP in EC inflammation. In vitro, EMP treatment significantly reduced tumour necrosis factor-α-induced endothelial intercellular adhesion molecule (ICAM)-1 expression on mRNA and protein level, whereas there was no effect on vascular cell adhesion molecule-1 expression. Reduced ICAM-1 expression after EMP treatment resulted in diminished monocyte adhesion in vitro. In vivo, systemic treatment of ApoE−/− mice with EMP significantly reduced murine endothelial ICAM-1 expression. To explore the underlying mechanisms, Taqman microRNA array was performed and microRNA (miR)-222 was identified as the strongest regulated miR between EMP and ECs. Following experiments demonstrated that miR-222 was transported into recipient ECs by EMP and functionally regulated expression of its target protein ICAM-1 in vitro and in vivo. After simulating diabetic conditions, EMP derived from glucose-treated ECs contained significantly lower amounts of miR-222 and showed reduced anti-inflammatory capacity in vitro and in vivo. Finally, circulating miR-222 level was diminished in patients with coronary artery disease (CAD) compared to patients without CAD. EMPs promote anti-inflammatory effects in vitro and in vivo by reducing endothelial ICAM-1 expression via the transfer of functional miR-222 into recipient cells. In pathological hyperglycaemic conditions, EMP-mediated miR-222-dependent anti-inflammatory effects are reduced. PMID:26081516

Endothelial microparticles reduce ICAM-1 expression in a microRNA-222-dependent mechanism.

PubMed

Jansen, Felix; Yang, Xiaoyan; Baumann, Katharina; Przybilla, David; Schmitz, Theresa; Flender, Anna; Paul, Kathrin; Alhusseiny, Adil; Nickenig, Georg; Werner, Nikos

2015-09-01

Endothelial microparticles (EMP) are released from activated or apoptotic endothelial cells (ECs) and can be taken up by adjacent ECs, but their effect on vascular inflammation after engulfment is largely unknown. We sought to determine the role of EMP in EC inflammation. In vitro, EMP treatment significantly reduced tumour necrosis factor-α-induced endothelial intercellular adhesion molecule (ICAM)-1 expression on mRNA and protein level, whereas there was no effect on vascular cell adhesion molecule-1 expression. Reduced ICAM-1 expression after EMP treatment resulted in diminished monocyte adhesion in vitro. In vivo, systemic treatment of ApoE-/- mice with EMP significantly reduced murine endothelial ICAM-1 expression. To explore the underlying mechanisms, Taqman microRNA array was performed and microRNA (miR)-222 was identified as the strongest regulated miR between EMP and ECs. Following experiments demonstrated that miR-222 was transported into recipient ECs by EMP and functionally regulated expression of its target protein ICAM-1 in vitro and in vivo. After simulating diabetic conditions, EMP derived from glucose-treated ECs contained significantly lower amounts of miR-222 and showed reduced anti-inflammatory capacity in vitro and in vivo. Finally, circulating miR-222 level was diminished in patients with coronary artery disease (CAD) compared to patients without CAD. EMPs promote anti-inflammatory effects in vitro and in vivo by reducing endothelial ICAM-1 expression via the transfer of functional miR-222 into recipient cells. In pathological hyperglycaemic conditions, EMP-mediated miR-222-dependent anti-inflammatory effects are reduced. © 2015 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

Development of functional biointerfaces by surface modification of polydimethylsiloxane with bioactive chlorogenic acid.

PubMed

Wu, Ming; He, Jia; Ren, Xiao; Cai, Wen-Sheng; Fang, Yong-Chun; Feng, Xi-Zeng

2014-04-01

The effect of physicochemical surface properties and chemical structure on the attachment and viability of bacteria and mammalian cells has been extensively studied for the development of biologically relevant applications. In this study, we report a new approach that uses chlorogenic acid (CA) to modify the surface wettability, anti-bacterial activity and cell adhesion properties of polydimethylsiloxane (PDMS). The chemical structure of the surface was obtained by X-ray photoelectron spectroscopy (XPS), the roughness was measured by atomic force microscopy (AFM), and the water contact angle was evaluated for PDMS substrates both before and after CA modification. Molecular modelling showed that the modification was predominately driven by van der Waals and electrostatic interactions. The exposed quinic-acid moiety improved the hydrophilicity of CA-modified PDMS substrates. The adhesion and viability of E. coli and HeLa cells were investigated using fluorescence and phase contrast microscopy. Few viable bacterial cells were found on CA-coated PDMS surfaces compared with unmodified PDMS surfaces. Moreover, HeLa cells exhibited enhanced adhesion and increased spreading on the modified PDMS surface. Thus, CA-coated PDMS surfaces reduced the ratio of viable bacterial cells and increased the adhesion of HeLa cells. These results contribute to the purposeful design of anti-bacterial surfaces for medical device use. Copyright © 2013 Elsevier B.V. All rights reserved.

Investigation of surface endothelialization on biomedical nitinol (NiTi) alloy: Effects of surface micropatterning combined with plasma nanocoatings.

PubMed

Shen, Yang; Wang, Guixue; Chen, Liang; Li, Hao; Yu, Ping; Bai, Mengjun; Zhang, Qin; Lee, James; Yu, Qingsong

2009-11-01

Plasma nanocoated films with trimethylsilane-oxygen monomers showed outstanding biocompatibility in our previous studies. In this study, endothelialization on biomedical nitinol alloy surfaces was systematically investigated. Our study focuses on elucidating the effects of surface micropatternings with micropores and microgrooves combined with plasma nanocoating. Plasma nanocoatings with controlled thickness between 40 and 50 nm were deposited onto micropatterned nitinol surface in a direct current plasma reactor. Bovine aortic endothelial cells were cultured in vitro on these nitinol samples for 1, 3 and 5 days. It was found that rougher surfaces could enhance cell adhesion compared with the smoother surfaces; the surfaces patterned with micropores showed much more endothelialization than microgrooved surface after a 3 days culture. The cell culture results also showed that plasma nanocoatings significantly further increased cell proliferation and cell adhesion on the micropatterned nitinol surfaces, as compared with non-plasma nanocoated surface of nitinol samples. The surface micropatternings combined with plasma nanocoatings could improve the cell adhesion and accelerate surface endothelialization after implantation of intravascular stents, which is expected to reduce in-stent restenosis.

Autophagy promotes degradation of internalized collagen and regulates distribution of focal adhesions to suppress cell adhesion

PubMed Central

Kawano, Shinichi; Esaki, Motohiro; Torisu, Kumiko; Matsuno, Yuichi; Kitazono, Takanari

2017-01-01

ABSTRACT Adhesion of cells to the extracellular matrix (ECM) via focal adhesions (FAs) is crucial for cell survival, migration, and differentiation. Although the regulation of FAs, including by integrins and the ECM, is important to cell behavior, how FAs are regulated is not well known. Autophagy is induced by both cell adhesion and cell detachment. Here, we showed that autophagosomes are located close to internalized collagen and paxillin, which is a well-known marker of FAs. Autophagy-deficient cells showed increased levels of internalized collagen compared with control cells. Moreover, paxillin exhibited a more peripheral distribution and the area of paxillin was increased, and adhesion-induced focal adhesion kinase signaling was impaired and adhesion was enhanced, in autophagy-deficient cells. These results suggest that autophagy suppressed cell adhesion by regulating internalized ECM and FAs. PMID:28970230

E-cadherin and cell adhesion: a role in architecture and function in the pancreatic islet.

PubMed

Rogers, Gareth J; Hodgkin, Matthew N; Squires, Paul E

2007-01-01

The efficient secretion of insulin from beta-cells requires extensive intra-islet communication. The cell surface adhesion protein epithelial (E)-cadherin (ECAD) establishes and maintains epithelial tissues such as the islets of Langerhans. In this study, the role of ECAD in regulating insulin secretion from pseudoislets was investigated. The effect of an immuno-neutralising ECAD on gross morphology, cytosolic calcium signalling, direct cell-to-cell communication and insulin secretion was assessed by fura-2 microfluorimetry, Lucifer Yellow dye injection and insulin ELISA in an insulin-secreting model system. Antibody blockade of ECAD reduces glucose-evoked changes in [Ca(2+)](i) and insulin secretion. Neutralisation of ECAD causes a breakdown in the glucose-stimulated synchronicity of calcium oscillations between discrete regions within the pseudoislet, and the transfer of dye from an individual cell within a cell cluster is attenuated in the absence of ECAD ligation, demonstrating that gap junction communication is disrupted. The functional consequence of neutralising ECAD is a significant reduction in insulin secretion. Cell adhesion via ECAD has distinct roles in the regulation of intercellular communication between beta-cells within islets, with potential repercussions for insulin secretion.

ARQ 092, an orally-available, selective AKT inhibitor, attenuates neutrophil-platelet interactions in sickle cell disease

PubMed Central

Kim, Kyungho; Li, Jing; Barazia, Andrew; Tseng, Alan; Youn, Seock-Won; Abbadessa, Giovanni; Yu, Yi; Schwartz, Brian; Andrews, Robert K.; Gordeuk, Victor R.; Cho, Jaehyung

2017-01-01

Previous studies identified the Ser/Thr protein kinase, AKT, as a therapeutic target in thrombo-inflammatory diseases. Here we report that specific inhibition of AKT with ARQ 092, an orally-available AKT inhibitor currently in phase Ib clinical trials as an anti-cancer drug, attenuates the adhesive function of neutrophils and platelets from sickle cell disease patients in vitro and cell-cell interactions in a mouse model of sickle cell disease. Studies using neutrophils and platelets isolated from sickle cell disease patients revealed that treatment with 50–500 nM ARQ 092 significantly blocks αMβ2 integrin function in neutrophils and reduces P-selectin exposure and glycoprotein Ib/IX/V-mediated agglutination in platelets. Treatment of isolated platelets and neutrophils with ARQ 092 inhibited heterotypic cell-cell aggregation under shear conditions. Intravital microscopic studies demonstrated that short-term oral administration of ARQ 092 or hydroxyurea, a major therapy for sickle cell disease, diminishes heterotypic cell-cell interactions in venules of sickle cell disease mice challenged with tumor necrosis factor-α. Co-administration of hydroxyurea and ARQ 092 further reduced the adhesive function of neutrophils in venules and neutrophil transmigration into alveoli, inhibited expression of E-selectin and intercellular adhesion molecule-1 in cremaster vessels, and improved survival in these mice. Ex vivo studies in sickle cell disease mice suggested that co-administration of hydroxyurea and ARQ 092 efficiently blocks neutrophil and platelet activation and that the beneficial effect of hydroxyurea results from nitric oxide production. Our results provide important evidence that ARQ 092 could be a novel drug for the prevention and treatment of acute vaso-occlusive complications in patients with sickle cell disease. PMID:27758820

Regulation of RAW 264.7 macrophages behavior on anodic TiO2 nanotubular arrays

NASA Astrophysics Data System (ADS)

Yao, Shenglian; Feng, Xujia; Li, Wenhao; Wang, Lu-Ning; Wang, Xiumei

2017-12-01

Titanium (Ti) implants with TiO2 nanotubular arrays on the surface could regulate cells adhesion, proliferation and differentiation to determine the bone integration. Additionally, the regulation of immune cells could improve osteogenesis or lead in appropriate immune reaction. Thus, we evaluate the behavior of RAW264.7 macrophages on TiO2 nanotubular arrays with a wide range diameter (from 20 to 120 nm) fabricated by an electrochemical anodization process. In this work, the proliferation, cell viability and cytokine/chemokine secretion were evaluated by CCK-8, live/dead staining and ELISA, respectively. SEM and confocal microscopy were used to observe the adhesion morphology. Results showed that the small size nanotube surface was benefit for the macrophages adhesion and proliferation, while larger size surface could reduce the inflammatory response. These findings contribute to the design of immune-regulating Ti implants surface that supports successful implantation.

Heterogeneous Cadherin Expression and Multicellular Aggregate Dynamics in Ovarian Cancer Dissemination.

PubMed

Klymenko, Yuliya; Johnson, Jeffrey; Bos, Brandi; Lombard, Rachel; Campbell, Leigh; Loughran, Elizabeth; Stack, M Sharon

2017-07-01

Epithelial ovarian carcinoma spreads via shedding of cells and multicellular aggregates (MCAs) from the primary tumor into peritoneal cavity, with subsequent intraperitoneal tumor cell:mesothelial cell adhesion as a key early event in metastatic seeding. Evaluation of human tumor extracts and tissues confirms that well-differentiated ovarian tumors express abundant E-cadherin (Ecad), whereas advanced lesions exhibit upregulated N-cadherin (Ncad). Two expression patterns are observed: "mixed cadherin," in which distinct cells within the same tumor express either E- or Ncad, and "hybrid cadherin," wherein single tumor cell(s) simultaneously expresses both cadherins. We demonstrate striking cadherin-dependent differences in cell-cell interactions, MCA formation, and aggregate ultrastructure. Mesenchymal-type Ncad+ cells formed stable, highly cohesive solid spheroids, whereas Ecad+ epithelial-type cells generated loosely adhesive cell clusters covered by uniform microvilli. Generation of "mixed cadherin" MCAs using fluorescently tagged cell populations revealed preferential sorting into cadherin-dependent clusters, whereas mixing of cell lines with common cadherin profiles generated homogeneous aggregates. Recapitulation of the "hybrid cadherin" Ecad+/Ncad+ phenotype, via insertion of the CDH2 gene into Ecad+ cells, resulted in the ability to form heterogeneous clusters with Ncad+ cells, significantly enhanced adhesion to organotypic mesomimetic cultures and peritoneal explants, and increased both migration and matrix invasion. Alternatively, insertion of CDH1 gene into Ncad+ cells greatly reduced cell-to-collagen, cell-to-mesothelium, and cell-to-peritoneum adhesion. Acquisition of the hybrid cadherin phenotype resulted in altered MCA surface morphology with increased surface projections and increased cell proliferation. Overall, these findings support the hypothesis that MCA cadherin composition impacts intraperitoneal cell and MCA dynamics and thereby affects ultimate metastatic success. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Antiatherosclerotic effects of Artemisia princeps Pampanini cv. Sajabal in LDL receptor deficient mice.

PubMed

Han, Jong-Min; Kim, Min-Jung; Baek, Seung-Hwa; An, Sojin; Jin, Yue-Yan; Chung, Hae-Gon; Baek, Nam-In; Choi, Myung-Sook; Lee, Kyung-Tae; Jeong, Tae-Sook

2009-02-25

Antiatherosclerotic effects of ethanolic extracts of Artemisia princeps Pampanini cv. Sajabal (ESJ) were investigated in low-density lipoprotein receptor deficient (LDLR(-/-)) mice. The Western diet-induced high levels of total cholesterol and triglyceride were similar in the ESJ and control groups. However, circulating oxidized LDL was significantly decreased in the ESJ group (p < 0.05). ESJ also markedly decreased aortic expression levels of intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), tumor necrosis factor-alpha (TNF-alpha), and interleukin-1 beta (IL-1 beta), and reduced the aortic lesion formation and macrophage accumulation by 36.7% (p < 0.05) and 43% (p < 0.01) in the control group, respectively. Additionally, ESJ inhibited atherogenic properties with cytokine-induced surface expression of cell adhesion molecules, chemokines, and monocyte adhesion to the human umbilical vein endothelial cells (HUVECs), and simultaneously suppressed nuclear factor-kappaB (NF-kappaB) activation. These results suggest that ethanolic extracts of Artemisia princeps Pampanini cv. Sajabal contributes to the antiatherosclerotic and anti-inflammatory activities in LDLR(-/-) mice.

Alpinia katsumadai Extracts Inhibit Adhesion and Invasion of Campylobacter jejuni in Animal and Human Foetal Small Intestine Cell Lines.

PubMed

Pogačar, Maja Šikić; Klančnik, Anja; Bucar, Franz; Langerholc, Tomaž; Možina, Sonja Smole

2015-10-01

Alpinia katsumadai is used in traditional Chinese medicine for abdominal distention, pain, and diarrhoea. Campylobacter jejuni is the most common cause of bacterial food-borne diarrhoeal illnesses worldwide. Adhesion to gut epithelium is a prerequisite in its pathogenesis. The antimicrobial, cytotoxic, and anti-adhesive activities of a chemically characterised extract (SEE) and its residual material of hydrodistillation (hdSEE-R) from A. katsumadai seeds were evaluated against C. jejuni. Minimal inhibitory concentrations for SEE and hdSEE-R were 0.5 mg/mL and 0.25 mg/mL, respectively, and there was no cytotoxic influence in the anti-adhesion tests, as these were performed at much lower concentrations of these tested plant extracts. Adhesion of C. jejuni to pig (PSI) and human foetal (H4) small-intestine cell lines was significantly decreased at lower concentrations (0.2 to 50 µg/mL). In the same concentration range, the invasiveness of C. jejuni in PSI cells was reduced by 45% to 65% when they were treated with SEE or hdSEE-R. The hdSEE-R represents a bioactive waste with a high phenolic content and an anti-adhesive activity against C. jejuni and thus has the potential for use in pharmaceutical and food products. Copyright © 2015 John Wiley & Sons, Ltd.

Memory T cells in organ transplantation: progress and challenges

PubMed Central

Espinosa, Jaclyn R.; Samy, Kannan P.; Kirk, Allan D.

2017-01-01

Antigen-experienced T cells, also known as memory T cells, are functionally and phenotypically distinct from naive T cells. Their enhanced expression of adhesion molecules and reduced requirement for co-stimulation enables them to mount potent and rapid recall responses to subsequent antigen encounters. Memory T cells generated in response to prior antigen exposures can cross-react with other nonidentical, but similar, antigens. This heterologous cross-reactivity not only enhances protective immune responses, but also engenders de novo alloimmunity. This latter characteristic is increasingly recognized as a potential barrier to allograft acceptance that is worthy of immunotherapeutic intervention, and several approaches have been investigated. Calcineurin inhibition effectively controls memory T-cell responses to allografts, but this benefit comes at the expense of increased infectious morbidity. Lymphocyte depletion eliminates allospecific T cells but spares memory T cells to some extent, such that patients do not completely lose protective immunity. Co-stimulation blockade is associated with reduced adverse-effect profiles and improved graft function relative to calcineurin inhibition, but lacks efficacy in controlling memory T-cell responses. Targeting the adhesion molecules that are upregulated on memory T cells might offer additional means to control co-stimulation-blockade-resistant memory T-cell responses. PMID:26923209

A Nasal Epithelial Receptor for Staphylococcus aureus WTA Governs Adhesion to Epithelial Cells and Modulates Nasal Colonization

PubMed Central

Faulstich, Manuela; Grau, Timo; Severin, Yannik; Unger, Clemens; Hoffmann, Wolfgang H.; Rudel, Thomas; Autenrieth, Ingo B.; Weidenmaier, Christopher

2014-01-01

Nasal colonization is a major risk factor for S. aureus infections. The mechanisms responsible for colonization are still not well understood and involve several factors on the host and the bacterial side. One key factor is the cell wall teichoic acid (WTA) of S. aureus, which governs direct interactions with nasal epithelial surfaces. We report here the first receptor for the cell wall glycopolymer WTA on nasal epithelial cells. In several assay systems this type F-scavenger receptor, termed SREC-I, bound WTA in a charge dependent manner and mediated adhesion to nasal epithelial cells in vitro. The impact of WTA and SREC-I interaction on epithelial adhesion was especially pronounced under shear stress, which resembles the conditions found in the nasal cavity. Most importantly, we demonstrate here a key role of the WTA-receptor interaction in a cotton rat model of nasal colonization. When we inhibited WTA mediated adhesion with a SREC-I antibody, nasal colonization in the animal model was strongly reduced at the early onset of colonization. More importantly, colonization stayed low over an extended period of 6 days. Therefore we propose targeting of this glycopolymer-receptor interaction as a novel strategy to prevent or control S. aureus nasal colonization. PMID:24788600

MEK1/2 inhibitors reverse acute vascular occlusion in mouse models of sickle cell disease.

PubMed

Zhao, Yulin; Schwartz, Evan A; Palmer, Gregory M; Zennadi, Rahima

2016-03-01

In sickle cell disease (SCD), treatment of recurrent vasoocclusive episodes, leading to pain crises and organ damage, is still a therapeutic challenge. Vasoocclusion is caused primarily by adherence of homozygous for hemoglobin S (SS) red blood cells (SSRBCs) and leukocytes to the endothelium. We tested the therapeutic benefits of MEK1/2 inhibitors in reversing vasoocclusion in nude and humanized SCD mouse models of acute vasoocclusive episodes using intravital microscopy. Administration of 0.2, 0.3, 1, or 2 mg/kg MEK1/2 inhibitor to TNF-α-pretreated nude mice before human SSRBC infusion inhibited SSRBC adhesion in inflamed vessels, prevented the progression of vasoocclusion, and reduced SSRBC organ sequestration. By use of a more clinically relevant protocol, 0.3 or 1 mg/kg MEK1/2 inhibitor given to TNF-α-pretreated nude mice after human SSRBC infusion and onset of vasoocclusion reversed SSRBC adhesion and vasoocclusion and restored blood flow. In SCD mice, 0.025, 0.05, or 0.1 mg/kg MEK1/2 inhibitor also reversed leukocyte and erythrocyte adhesion after the inflammatory trigger of vasoocclusion and improved microcirculatory blood flow. Cell adhesion was reversed by shedding of endothelial E-selectin, P-selectin, and αvβ3 integrin, and leukocyte CD44 and β2 integrin. Thus, MEK1/2 inhibitors, by targeting the adhesive function of SSRBCs and leukocytes, could represent a valuable therapeutic intervention for acute sickle cell vasoocclusive crises. © FASEB.

Uncovering a Role for the Tail of the Dictyostelium discoideum SadA Protein in Cell-Substrate Adhesion ▿ †

PubMed Central

Kowal, Anthony S.; Chisholm, Rex L.

2011-01-01

Previous work from our laboratory showed that the Dictyostelium discoideum SadA protein plays a central role in cell-substrate adhesion. SadA null cells exhibit a loss of adhesion, a disrupted actin cytoskeleton, and a cytokinesis defect. How SadA mediates these phenotypes is unknown. This work addresses the mechanism of SadA function, demonstrating an important role for the C-terminal cytoplasmic tail in SadA function. We found that a SadA tailless mutant was unable to rescue the sadA adhesion deficiency, and overexpression of the SadA tail domain reduced adhesion in wild-type cells. We also show that SadA is closely associated with the actin cytoskeleton. Mutagenesis studies suggested that four serine residues in the tail, S924/S925 and S940/S941, may regulate association of SadA with the actin cytoskeleton. Glutathione S-transferase pull-down assays identified at least one likely interaction partner of the SadA tail, cortexillin I, a known actin bundling protein. Thus, our data demonstrate an important role for the carboxy-terminal cytoplasmic tail in SadA function and strongly suggest that a phosphorylation event in this tail regulates an interaction with cortexillin I. Based on our data, we propose a model for the function of SadA. PMID:21441344

Suppression of complement regulatory protein C1 inhibitor in vascular endothelial activation by inhibiting vascular cell adhesion molecule-1 action

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Haimou; Qin, Gangjian; Liang, Gang

Increased expression of adhesion molecules by activated endothelium is a critical feature of vascular inflammation associated with the several diseases such as endotoxin shock and sepsis/septic shock. Our data demonstrated complement regulatory protein C1 inhibitor (C1INH) prevents endothelial cell injury. We hypothesized that C1INH has the ability of an anti-endothelial activation associated with suppression of expression of adhesion molecule(s). C1INH blocked leukocyte adhesion to endothelial cell monolayer in both static assay and flow conditions. In inflammatory condition, C1INH reduced vascular cell adhesion molecule (VCAM-1) expression associated with its cytoplasmic mRNA destabilization and nuclear transcription level. Studies exploring the underlying mechanismmore » of C1INH-mediated suppression in VCAM-1 expression were related to reduction of NF-{kappa}B activation and nuclear translocation in an I{kappa}B{alpha}-dependent manner. The inhibitory effects were associated with reduction of inhibitor I{kappa}B kinase activity and stabilization of the NF-{kappa}B inhibitor I{kappa}B. These findings indicate a novel role for C1INH in inhibition of vascular endothelial activation. These observations could provide the basis for new therapeutic application of C1INH to target inflammatory processes in different pathologic situations.« less

Abscisic acid ameliorates experimental IBD by downregulating cellular adhesion molecule expression and suppressing immune cell infiltration.

PubMed

Guri, Amir J; Hontecillas, Raquel; Bassaganya-Riera, Josep

2010-12-01

Abscisic acid (ABA) has shown effectiveness in ameliorating inflammation in obesity, diabetes and cardiovascular disease models. The objective of this study was to determine whether ABA prevents or ameliorates experimental inflammatory bowel disease (IBD). C57BL/6J mice were fed diets with or without ABA (100mg/kg) for 35 days prior to challenge with 2.5% dextran sodium sulfate (DSS). The severity of clinical disease was assessed daily. Colonic mucosal lesions were evaluated by histopathology, and cellular adhesion molecular and inflammatory markers were assayed by real-time quantitative PCR. Flow cytometry was used to quantify leukocyte populations in the blood, spleen, and mesenteric lymph nodes (MLN). The effect of ABA on cytotoxic T-lymphocyte antigen 4 (CTLA-4) expression in splenocytes was also investigated. ABA significantly ameliorated disease activity, colitis and reduced colonic leukocyte infiltration and inflammation. These improvements were associated with downregulation in vascular cell adhesion marker-1 (VCAM-1), E-selectin, and mucosal addressin adhesion marker-1 (MAdCAM-1) expression. ABA also increased CD4(+) and CD8(+) T-lymphocytes in blood and MLN and regulatory T cells in blood. In vitro, ABA increased CTLA-4 expression through a PPAR γ-dependent mechanism. We conclude that ABA ameliorates gut inflammation by modulating T cell distribution and adhesion molecule expression. Copyright © 2010 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

Abscisic acid ameliorates experimental IBD by downregulating cellular adhesion molecule expression and suppressing immune cell infiltration

PubMed Central

Guri, Amir J; Hontecillas, Raquel; Bassaganya-Riera, Josep

2010-01-01

Background & Aims Abscisic acid (ABA) has shown effectiveness in ameliorating inflammation in obesity, diabetes and cardiovascular disease models. The objective of this study was to determine whether ABA prevents or ameliorates experimental inflammatory bowel disease (IBD). Methods C57BL/6J mice were fed diets with or without ABA (100 mg/kg) for 35 days prior to challenge with 2.5% dextran sodium sulfate (DSS). The severity of clinical disease was assessed daily. Colonic mucosal lesions were evaluated by histopathology, and cellular adhesion molecular and inflammatory markers were assayed by real-time quantitative PCR. Flow cytometry was used to quantify leukocyte populations in the blood, spleen, and mesenteric lymph nodes (MLN). The effect of ABA on cytotoxic T-lymphocyte antigen 4 (CTLA-4) expression in splenocytes was also investigated. Results ABA significantly ameliorated disease activity, colitis and reduced colonic leukocyte infiltration and inflammation. These improvements were associated with down-regulation in vascular cell adhesion marker-1 (VCAM-1), E-selectin, and mucosal addressin adhesion marker-1 (MAdCAM-1) expression. ABA also increased CD4+ and CD8+ T-lymphocytes in blood and MLN and regulatory T-cells in blood. In vitro, ABA increased CTLA-4 expression through a PPAR γ-dependent mechanism. Conclusions We conclude that ABA ameliorates gut inflammation by modulating T cell distribution and adhesion molecule expression. PMID:20236740

Plasma functionalization of polycarbonaturethane to improve endothelialization--Effect of shear stress as a critical factor for biocompatibility control.

PubMed

Lukas, Karin; Thomas, Ulrich; Gessner, André; Wehner, Daniel; Schmid, Thomas; Schmid, Christof; Lehle, Karla

2016-04-01

Medical devices made of polycarbonaturethane (PCU) combine excellent mechanical properties and little biological degradation, but restricted hemocompatibility. Modifications of PCU might reduce platelet adhesion and promote stable endothelialization. PCU was modified using gas plasma treatment, binding of hydrogels, and coupling of cell-active molecules (modified heparin, anti-thrombin III (ATIII), argatroban, fibronectin, laminin-nonapeptide, peptides with integrin-binding arginine-glycine-aspartic acid (RGD) motif). Biocompatibility was verified with static and dynamic cell culture techniques. Blinded analysis focused on improvement in endothelial cell (EC) adhesion/proliferation, anti-thrombogenicity, reproducible manufacturing process, and shear stress tolerance of ECs. EC adhesion and antithrombogenicity were achieved with 9/35 modifications. Additionally, 6/9 stimulated EC proliferation and 3/6 modification processes were highly reproducible for endothelialization. The latter modifications comprised immobilization of ATIII (A), polyethyleneglycole-diamine-hydrogel (E) and polyethylenimine-hydrogel connected with modified heparin (IH). Under sheer stress, only the IH modification improved EC adhesion within the graft. However, ECs did not arrange in flow direction and cell anchorage was restricted. Despite large variation in surface modification chemistry and improved EC adhesion under static culture conditions, additional introduction of shear stress foiled promising preliminary data. Therefore, biocompatibility testing required not only static tests but also usage of physiological conditions such as shear stress in the case of vascular grafts. © The Author(s) 2016.

Epithelial Microvilli Establish an Electrostatic Barrier to Microbial Adhesion

PubMed Central

Bennett, Kaila M.; Walker, Sharon L.

2014-01-01

Microvilli are membrane extensions on the apical surface of polarized epithelia, such as intestinal enterocytes and tubule and duct epithelia. One notable exception in mucosal epithelia is M cells, which are specialized for capturing luminal microbial particles; M cells display a unique apical membrane lacking microvilli. Based on studies of M cell uptake under different ionic conditions, we hypothesized that microvilli may augment the mucosal barrier by providing an increased surface charge density from the increased membrane surface and associated glycoproteins. Thus, electrostatic charges may repel microbes from epithelial cells bearing microvilli, while M cells are more susceptible to microbial adhesion. To test the role of microvilli in bacterial adhesion and uptake, we developed polarized intestinal epithelial cells with reduced microvilli (“microvillus-minus,” or MVM) but retaining normal tight junctions. When tested for interactions with microbial particles in suspension, MVM cells showed greatly enhanced adhesion and uptake of particles compared to microvillus-positive cells. This preference showed a linear relationship to bacterial surface charge, suggesting that microvilli resist binding of microbes by using electrostatic repulsion. Moreover, this predicts that pathogen modification of electrostatic forces may contribute directly to virulence. Accordingly, the effacement effector protein Tir from enterohemorrhagic Escherichia coli O157:H7 expressed in epithelial cells induced a loss of microvilli with consequent enhanced microbial binding. These results provide a new context for microvillus function in the host-pathogen relationship, based on electrostatic interactions. PMID:24778113

Amygdalin blocks the in vitro adhesion and invasion of renal cell carcinoma cells by an integrin-dependent mechanism.

PubMed

Juengel, Eva; Afschar, Masud; Makarević, Jasmina; Rutz, Jochen; Tsaur, Igor; Mani, Jens; Nelson, Karen; Haferkamp, Axel; Blaheta, Roman A

2016-03-01

Information about the natural compound amygdalin, which is employed as an antitumor agent, is sparse and thus its efficacy remains controversial. In this study, to determine whether amygdalin exerts antitumor effects on renal cell carcinoma (RCC) cells, its impact on RCC metastatic activity was investigated. The RCC cell lines, Caki-1, KTC-26 and A498, were exposed to amygdalin from apricot kernels, and adhesion to human vascular endothelium, immobilized collagen or fibronectin was investigated. The influence of amygdalin on chemotactic and invasive activity was also determined, as was the influence of amygdalin on surface and total cellular α and β integrin expression, which are involved in metastasis. We noted that amygdalin caused significant reductions in chemotactic activity, invasion and adhesion to endothelium, collagen and fibronectin. Using FACScan analysis, we noted that amygdalin also induced reductions, particularly in integrins α5 and α6, in all three cell lines. Functional blocking of α5 resulted in significantly diminished adhesion of KTC-26 and A498 to collagen and also in decreased chemotactic behavior in all three cell lines. Blocking α6 integrin significantly reduced chemotactic activity in all three cell lines. Thus, we suggest that exposing RCC cells to amygdalin inhibits metastatic spread and is associated with downregulation of α5 and α6 integrins. Therefore, we posit that amygdalin exerts antitumor activity in vitro, and this may be linked to integrin regulation.

P-glycoprotein Mediates Postoperative Peritoneal Adhesion Formation by Enhancing Phosphorylation of the Chloride Channel-3

PubMed Central

Deng, Lulu; Li, Qin; Lin, Guixian; Huang, Dan; Zeng, Xuxin; Wang, Xinwei; Li, Ping; Jin, Xiaobao; Zhang, Haifeng; Li, Chunmei; Chen, Lixin; Wang, Liwei; Huang, Shulin; Shao, Hongwei; Xu, Bin; Mao, Jianwen

2016-01-01

P-glycoprotein (P-gp) is encoded by the multidrug resistance (MDR1) gene and is well studied as a multi-drug resistance transporter. Peritoneal adhesion formation following abdominal surgery remains an important clinical problem. Here, we found that P-gp was highly expressed in human adhesion fibroblasts and promoted peritoneal adhesion formation in a rodent model. Knockdown of P-gp expression by intraperitoneal injection of MDR1-targeted siRNA significantly reduced both the peritoneal adhesion development rate and adhesion grades. Additionally, we found that operative injury up-regulated P-gp expression in peritoneal fibroblasts through the TGF-β1/Smad signaling pathway and histone H3 acetylation. The overexpression of P-gp accelerated migration and proliferation of fibroblasts via volume-activated Cl- current and cell volume regulation by enhancing phosphorylation of the chloride channel-3. Therefore, P-gp plays a critical role in postoperative peritoneal adhesion formation and may be a valuable therapeutic target for preventing the formation of peritoneal adhesions. PMID:26877779

Suppression of the PI3K subunit p85α delays embryoid body development and inhibits cell adhesion.

PubMed

Gurney, Susan M R; Forster, Peter; Just, Ursula; Schwanbeck, Ralf

2011-12-01

Phosphatidylinositol-3-kinases (PI3Ks) exert a variety of signaling functions in eukaryotes. We suppressed the PI3K regulatory subunit p85α using a small interfering RNA (Pik3r1 siRNA) and examined the effects on embryoid body (EB) development in hanging drop culture. We observed a 150% increase in the volume of the treated EBs within 24 h, compared to the negative controls. Fluorescence Activated Cell Sorting (FACS) assays showed that this increase in volume is not due to increased cellular proliferation. Instead, the increase in volume appears to be due to reduced cellular aggregation and adherence. This is further shown by our observation that 40% of treated EBs form twin instead of single EBs, and that they have a significantly reduced ability to adhere to culture dishes when plated. A time course over the first 96 h reveals that the impaired adherence is transient and explained by an initial 12-hour delay in EB development. Quantitative PCR expression analysis suggests that the adhesion molecule integrin-β1 (ITGB1) is transiently downregulated by the p85α suppression. In conclusion we found that suppressing p85α leads to a delay in forming compact EBs, accompanied by a transient inability of the EBs to undergo normal cell-cell and cell-substrate adhesion. Copyright © 2011 Wiley Periodicals, Inc.

Integrin expression and integrin-mediated adhesion in vitro of human multipotent stromal cells (MSCs) to endothelial cells from various blood vessels.

PubMed

Semon, Julie A; Nagy, Lauren H; Llamas, Claire B; Tucker, H Alan; Lee, Ryang Hwa; Prockop, Darwin J

2010-07-01

Multipotent mesenchymal stromal cells (MSCs) home to damaged tissue by processes partly regulated by integrins. Integrin subunits expressed by MSCs were identified by flow cytometry (FC), immunocytochemistry (IC), and a panel of integrin-binding antibodies. In subconfluent cultures, over 80% of MSCs expressed integrin subunits beta1, beta2, and alpha3, 20%-55% expressed alpha1, alpha2, alpha4, alpha5, alpha6, and alphaV, and about 10% expressed beta3 when assayed by FC. None of the cells expressed significant levels of 13 other integrins as assayed by FC, but seven of the 13 integrins were detected by IC: beta5, alpha7, alpha8, alpha9, alpha11, alphaX, and alphaD. Expression of some integrins changed with MSC confluency: integrins beta3, alpha1, alpha3, alpha5, and alphaV increased, and alpha6 decreased. Furthermore, alpha4 was the only integrin to vary among preparations of MSCs from different donors. The results resolved some discrepancies in the literature concerning integrin expression by MSCs. We also investigated the role of specific integrins in MSC adhesion to endothelial cells (ECs) from the pulmonary artery (HPAEC), cardiac-derived microvasculature (HMVEC-C), and umbilical veins (HUVEC). In experiments with blocking antibodies to beta integrins, anti-beta5 reduced MSC adhesion to all types of ECs, anti-beta1 to both HUVEC and HPAEC, anti-beta3 to HUVEC, and anti-beta2 to HMVEC-C. With blocking antibodies to alpha integrins, anti-alphaX reduced adhesion to HPAEC and HMVEC-C, anti-alphaV to HPAEC, and both anti-alpha7 and anti-alphaD to HMVEC-C. Thus, MSCs use diverse integrins to adhere to EC from various blood vessels in vitro.

Mycoplasma bovis NADH oxidase functions as both a NADH oxidizing and O2 reducing enzyme and an adhesin.

PubMed

Zhao, Gang; Zhang, Hui; Chen, Xi; Zhu, Xifang; Guo, Yusi; He, Chenfei; Anwar Khan, Farhan; Chen, Yingyu; Hu, Changmin; Chen, Huanchun; Guo, Aizhen

2017-03-03

Mycoplasma bovis causes considerable economic losses in the cattle industry worldwide. In mycoplasmal infections, adhesion to the host cell is of the utmost importance. In this study, the amino acid sequence of NOX was predicted to have enzymatic domains. The nox gene was then cloned and expressed in Escherichia coli. The enzymatic activity of recombinant NOX (rNOX) was confirmed based on its capacity to oxidize NADH to NAD + and reduce O 2 to H 2 O 2 . The adherence of rNOX to embryonic bovine lung (EBL) cells was confirmed with confocal laser scanning microscopy, enzyme-linked immunosorbent assay, and flow cytometry. Both preblocking EBL cells with purified rNOX and preneutralizing M. bovis with polyclonal antiserum to rNOX significantly reduced the adherence of M. bovis to EBL cells. Mycoplasma bovis NOX- expressed a truncated NOX protein at a level 10-fold less than that of the wild type. The capacities of M. bovis NOX- for cell adhesion and H 2 O 2 production were also significantly reduced. The rNOX was further used to pan phage displaying lung cDNA library and fibronectin was determined to be potential ligand. In conclusion, M. bovis NOX functions as both an active NADH oxidase and adhesin, and is therefore a potential virulence factor.

Changes in E-cadherin rigidity sensing regulate cell adhesion.

PubMed

Collins, Caitlin; Denisin, Aleksandra K; Pruitt, Beth L; Nelson, W James

2017-07-18

Mechanical cues are sensed and transduced by cell adhesion complexes to regulate diverse cell behaviors. Extracellular matrix (ECM) rigidity sensing by integrin adhesions has been well studied, but rigidity sensing by cadherins during cell adhesion is largely unexplored. Using mechanically tunable polyacrylamide (PA) gels functionalized with the extracellular domain of E-cadherin (Ecad-Fc), we showed that E-cadherin-dependent epithelial cell adhesion was sensitive to changes in PA gel elastic modulus that produced striking differences in cell morphology, actin organization, and membrane dynamics. Traction force microscopy (TFM) revealed that cells produced the greatest tractions at the cell periphery, where distinct types of actin-based membrane protrusions formed. Cells responded to substrate rigidity by reorganizing the distribution and size of high-traction-stress regions at the cell periphery. Differences in adhesion and protrusion dynamics were mediated by balancing the activities of specific signaling molecules. Cell adhesion to a 30-kPa Ecad-Fc PA gel required Cdc42- and formin-dependent filopodia formation, whereas adhesion to a 60-kPa Ecad-Fc PA gel induced Arp2/3-dependent lamellipodial protrusions. A quantitative 3D cell-cell adhesion assay and live cell imaging of cell-cell contact formation revealed that inhibition of Cdc42, formin, and Arp2/3 activities blocked the initiation, but not the maintenance of established cell-cell adhesions. These results indicate that the same signaling molecules activated by E-cadherin rigidity sensing on PA gels contribute to actin organization and membrane dynamics during cell-cell adhesion. We hypothesize that a transition in the stiffness of E-cadherin homotypic interactions regulates actin and membrane dynamics during initial stages of cell-cell adhesion.

Biophysical Effects of a Polymeric Biosurfactant in Candida krusei and Candida albicans Cells.

PubMed

Ferreira, Gabriella Freitas; Dos Santos Pinto, Bruna Lorrana; Souza, Eliene Batista; Viana, José Lima; Zagmignan, Adrielle; Dos Santos, Julliana Ribeiro Alves; Santos, Áquila Rodrigues Costa; Tavares, Priscila Batista; Denadai, Ângelo Márcio Leite; Monteiro, Andrea Souza

2016-12-01

This study evaluated the effects of a polymeric biosurfactant produced by Trichosporon montevideense CLOA72 in the adhesion of Candida albicans and Candida krusei cells to human buccal epithelial cells and its interference in biofilm formation by these strains. The biofilm inhibition by biosurfactant (25 mg/mL) in C. krusei and C. albicans in polystyrene was reduced up to 79.5 and 85 %, respectively. In addition, the zeta potential and hydrodynamic diameter of the yeasts altered as a function of the biosurfactant concentration added to the cell suspension. The changes in the cell surface characteristics and the interface modification can contribute to the inhibition of the initial adherence of yeasts cells to the surface. In addition, the analyses of the biofilm matrix and planktonic cell surfaces demonstrated differences in carbohydrate and protein concentrations for the two studied strains, which may contribute to the modulation of cell adhesion or consolidation of biofilms, especially in C. krusei. This study suggests a possible application of the of CLOA72 biosurfactant in inhibiting the adhesion and formation of biofilms on biological surfaces by yeasts of the Candida genus.

Oligosaccharide receptor mimics inhibit Legionella pneumophila attachment to human respiratory epithelial cells.

PubMed

Thomas, Richard J; Brooks, Tim J

2004-02-01

Legionnaire's disease is caused by the intracellular pathogen Legionella pneumophila, presenting as an acute pneumonia. Attachment is the key step during infection, often relying on an interaction between host cell oligosaccharides and bacterial adhesins. Inhibition of this interaction by receptor mimics offers possible novel therapeutic treatments. L. pneumophila attachment to the A549 cell line was significantly reduced by treatment with tunicamycin (73.6%) and sodium metaperiodate (63.7%). This indicates the importance of cell surface oligosaccharide chains in adhesion. A number of putative anti-adhesion compounds inhibited attachment to the A549 and U937 cell lines. The most inhibitory compounds were polymeric saccharides, GalNAcbeta1-4Gal, Galbeta1-4GlcNAc and para-nitrophenol. These compounds inhibited adhesion to a range of human respiratory cell lines, including nasal epithelial, bronchial epithelial and alveolar epithelial cell lines and the human monocytic cell line, U937. Some eukaryotic receptors for L. pneumophila were determined to be the glycolipids, asialo-GM1 and asialo-GM2 that contain the inhibitory saccharide moiety, GalNAcbeta1-4Gal. The identified compounds have the potential to be used as novel treatments for Legionnaire's disease.

Regulation of human cerebro-microvascular endothelial baso-lateral adhesion and barrier function by S1P through dual involvement of S1P1 and S1P2 receptors.

PubMed

Wiltshire, Rachael; Nelson, Vicky; Kho, Dan Ting; Angel, Catherine E; O'Carroll, Simon J; Graham, E Scott

2016-01-27

Herein we show that S1P rapidly and acutely reduces the focal adhesion strength and barrier tightness of brain endothelial cells. xCELLigence biosensor technology was used to measure focal adhesion, which was reduced by S1P acutely and this response was mediated through both S1P1 and S1P2 receptors. S1P increased secretion of several pro-inflammatory mediators from brain endothelial cells. However, the magnitude of this response was small in comparison to that mediated by TNFα or IL-1β. Furthermore, S1P did not significantly increase cell-surface expression of any key cell adhesion molecules involved in leukocyte recruitment, included ICAM-1 and VCAM-1. Finally, we reveal that S1P acutely and dynamically regulates microvascular endothelial barrier tightness in a manner consistent with regulated rapid opening followed by closing and strengthening of the barrier. We hypothesise that the role of the S1P receptors in this process is not to cause barrier dysfunction, but is related to controlled opening of the endothelial junctions. This was revealed using real-time measurement of barrier integrity using ECIS ZΘ TEER technology and endothelial viability using xCELLigence technology. Finally, we show that these responses do not occur simply though the pharmacology of a single S1P receptor but involves coordinated action of S1P1 and S1P2 receptors.

Influence of airway wall compliance on epithelial cell injury and adhesion during interfacial flows

PubMed Central

Higuita-Castro, Natalia; Mihai, Cosmin; Hansford, Derek J.

2014-01-01

Interfacial flows during cyclic airway reopening are an important source of ventilator-induced lung injury. However, it is not known how changes in airway wall compliance influence cell injury during airway reopening. We used an in vitro model of airway reopening in a compliant microchannel to investigate how airway wall stiffness influences epithelial cell injury. Epithelial cells were grown on gel substrates with different rigidities, and cellular responses to substrate stiffness were evaluated in terms of metabolic activity, mechanics, morphology, and adhesion. Repeated microbubble propagations were used to simulate cyclic airway reopening, and cell injury and detachment were quantified via live/dead staining. Although cells cultured on softer gels exhibited a reduced elastic modulus, these cells experienced less plasma membrane rupture/necrosis. Cells on rigid gels exhibited a minor, but statistically significant, increase in the power law exponent and also exhibited a significantly larger height-to-length aspect ratio. Previous studies indicate that this change in morphology amplifies interfacial stresses and, therefore, correlates with the increased necrosis observed during airway reopening. Although cells cultured on stiff substrates exhibited more plasma membrane rupture, these cells experienced significantly less detachment and monolayer disruption during airway reopening. Western blotting and immunofluorescence indicate that this protection from detachment and monolayer disruption correlates with increased focal adhesion kinase and phosphorylated paxillin expression. Therefore, changes in cell morphology and focal adhesion structure may govern injury responses during compliant airway reopening. In addition, these results indicate that changes in airway compliance, as occurs during fibrosis or emphysema, may significantly influence cell injury during mechanical ventilation. PMID:25213636

Potential-Induced Degradation-Delamination Mode in Crystalline Silicon Modules: Preprint

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hacke, Peter L; Kempe, Michael D; Wohlgemuth, John

A test sequence producing potential-induced degradation-delamination (PID-d) in crystalline silicon modules has been tested and found comparable under visual inspection to cell/encapsulant delamination seen in some fielded modules. Four commercial modules were put through this sequence, 85 degrees C, 85%, 1000 h damp heat, followed by an intensive PID stress sequence of 72 degrees C, 95% RH, and -1000 V, with the module face grounded using a metal foil. The 60 cell c-Si modules exhibiting the highest current transfer (4.4 center dot 10-4 A) exhibited PID-d at the first inspection after 156 h of PID stress. Effects promoting PID-d aremore » reduced adhesion caused by damp heat, sodium migration further reducing adhesion to the cells, and gaseous products of electrochemical reactions driven by the applied system voltage. A new work item proposal for an IEC test standard to evaluate for PID-d is anticipated.« less

PDGF Suppresses the Sulfation of CD44v and Potentiates CD44v-Mediated Binding of Colon Carcinoma Cells to Fibrin under Flow

PubMed Central

Alves, Christina S.; Konstantopoulos, Konstantinos

2012-01-01

Fibrin(ogen) mediates sustained tumor cell adhesion and survival in the pulmonary vasculature, thereby facilitating the metastatic dissemination of tumor cells. CD44 is the major functional fibrin receptor on colon carcinoma cells. Growth factors, such as platelet-derived growth factor (PDGF), induce post-translational protein modifications, which modulate ligand binding activity. In view of the roles of PDGF, fibrin(ogen) and CD44 in cancer metastasis, we aimed to delineate the effect of PDGF on CD44-fibrin recognition. By immunoprecipitating CD44 from PDGF-treated and untreated LS174T colon carcinoma cells, which express primarily CD44v, we demonstrate that PDGF enhances the adhesion of CD44v-coated beads to immobilized fibrin. Enzymatic inhibition studies coupled with flow-based adhesion assays and autoradiography reveal that PDGF augments the binding of CD44v to fibrin by significantly attenuating the extent of CD44 sulfation primarily on chondroitin and dermatan sulfate chains. Surface plasmon resonance assays confirm that PDGF enhances the affinity of CD44v-fibrin binding by markedly reducing its dissociation rate while modestly increasing the association rate. PDGF mildly reduces the affinity of CD44v-hyaluronan binding without affecting selectin-CD44v recognition. The latter is attributed to the fact that CD44v binds to selectins via sialofucosylated O-linked residues independent of heparan, dermatan and chondroitin sulfates. Interestingly, PDGF moderately reduces the sulfation of CD44s and CD44s-fibrin recognition. Collectively, these data offer a novel perspective into the mechanism by which PGDF regulates CD44-dependent binding of metastatic colon carcinoma cells to fibrin(ogen). PMID:23056168

There are four dynamically and functionally distinct populations of E-cadherin in cell junctions

PubMed Central

Erami, Zahra; Timpson, Paul; Yao, Wu; Zaidel-Bar, Ronen; Anderson, Kurt I.

2015-01-01

ABSTRACT E-cadherin is a trans-membrane tumor suppressor responsible for epithelial cell adhesion. E-cadherin forms adhesive clusters through combined extra-cellular cis- and trans-interactions and intracellular interaction with the actin cytoskeleton. Here we identify four populations of E-cadherin within cell junctions based on the molecular interactions which determine their mobility and adhesive properties. Adhesive and non-adhesive populations of E-cadherin each consist of mobile and immobile fractions. Up to half of the E-cadherin immobilized in cell junctions is non-adhesive. Incorporation of E-cadherin into functional adhesions require all three adhesive interactions, with deletion of any one resulting in loss of effective cell-cell adhesion. Interestingly, the only interaction which could independently slow the diffusion of E-cadherin was the tail-mediated intra-cellular interaction. The adhesive and non-adhesive mobile fractions of E-cadherin can be distinguished by their sensitivity to chemical cross-linking with adhesive clusters. Our data define the size, mobility, and adhesive properties of four distinct populations of E-cadherin within cell junctions, and support association with the actin cytoskeleton as the first step in adhesion formation. PMID:26471767

Heterofunctional nanosheet controlling cell adhesion properties by collagen coating.

PubMed

Niwa, Daisuke; Fujie, Toshinori; Lang, Thorsten; Goda, Nobuhito; Takeoka, Shinji

2012-08-01

Recently, biomaterials have been widely used in a variety of medical applications. We previously reported that a poly-l-lactic acid (PLLA) nanosheet shows anti-adhesive properties and constitutes a useful biomaterial for preventing unwanted wound adhesion in surgical operations. In this article, we examine whether the PLLA nanosheet can be specifically modified with biomacromolecules on one surface only. Such an approach would endow each side of the nanosheet with discrete functions, that is anti-adhesive and pro-healing properties. We fabricated two distinct PLLA nanosheets: (i) collagen cast on the surface of a PLLA nanosheet (Col-Cast-PLLA) and (ii) collagen spin-coated on the nanosheet (Col-Spin-PLLA). In the Col-Spin-PLLA nanosheet, the collagen layer had a thickness of 5-10 nm on the PLLA surface and displayed increased hydrophilicity compared to both PLLA and Col-Cast-PLLA nanosheets. In addition, atomic force microscopy showed disorganized collagen fibril formation on the PLLA layer when covered using the spin-coating method, while apparent bundle formations of collagen were formed in the Col-Cast-PLLA nanosheet. The Col-Spin-PLLA nanosheet provided a microenvironment for cells to adhere and spread. By contrast, the Col-Cast-PLLA nanosheet displayed reduced cell adhesion compared to the Col-Spin-PLLA nanosheet. Consistent with these findings, immunocytochemical analysis clearly showed fine networks of actin filaments in cells cultured on the Col-Spin-PLLA, but not the Col-Cast-PLLA nanosheet. Therefore, the Col-Spin-PLLA nanosheet was shown to be more suitable for acting as a scaffold. In conclusion, we have succeeded in developing a heterofunctional nanosheet comprising a collagen modified side, which has the ability to rapidly adhere cells, and an unmodified side, which acts as an adhesion barrier, by using a spin-coating technique.

Resistance to protein adsorption and adhesion of fibroblasts on nanocrystalline diamond films: the role of topography and boron doping.

PubMed

Alcaide, María; Papaioannou, Stavros; Taylor, Andrew; Fekete, Ladislav; Gurevich, Leonid; Zachar, Vladimir; Pennisi, Cristian Pablo

2016-05-01

Boron-doped nanocrystalline diamond (BNCD) films exhibit outstanding electrochemical properties that make them very attractive for the fabrication of electrodes for novel neural interfaces and prosthetics. In these devices, the physicochemical properties of the electrode materials are critical to ensure an efficient long-term performance. The aim of this study was to investigate the relative contribution of topography and doping to the biological performance of BNCD films. For this purpose, undoped and boron-doped NCD films were deposited on low roughness (LR) and high roughness (HR) substrates, which were studied in vitro by means of protein adsorption and fibroblast growth assays. Our results show that BNCD films significantly reduce the adsorption of serum proteins, mostly on the LR substrates. As compared to fibroblasts cultured on LR BNCD films, cells grown on the HR BNCD films showed significantly reduced adhesion and lower growth rates. The mean length of fibronectin fibrils deposited by the cells was significantly increased in the BNCD coated substrates, mainly in the LR surfaces. Overall, the largest influence on protein adsorption, cell adhesion, proliferation, and fibronectin deposition was due to the underlying sub-micron topography, with little or no influence of boron doping. In perspective, BNCD films displaying surface roughness in the submicron range may be used as a strategy to reduce the fibroblast growth on the surface of neural electrodes.

ICAM-1 is necessary for epithelial recruitment of gammadelta T cells and efficient corneal wound healing.

USDA-ARS?s Scientific Manuscript database

Wound healing and inflammation are both significantly reduced in mice that lack gammadelta T cells. Here, the role of epithelial intercellular adhesion molecule-1 (ICAM-1) in gammadelta T cell migration in corneal wound healing was assessed. Wild-type mice had an approximate fivefold increase in epi...

Soft Lithography and Minimally Human Invasive Technique for Rapid Screening of Oral Biofilm Formation on New Microfabricated Dental Material Surfaces

PubMed Central

Alvarez-Escobar, Marta; Hansford, Derek; Monteiro, Fernando J.

2018-01-01

Introduction Microfabrication offers opportunities to study surface concepts focused to reduce bacterial adhesion on implants using human minimally invasive rapid screening (hMIRS). Wide information is available about cell/biomaterial interactions using eukaryotic and prokaryotic cells on surfaces of dental materials with different topographies, but studies using human being are still limited. Objective To evaluate a synergy of microfabrication and hMIRS to study the bacterial adhesion on micropatterned surfaces for dental materials. Materials and Methods Micropatterned and flat surfaces on biomedical PDMS disks were produced by soft lithography. The hMIRS approach was used to evaluate the total oral bacterial adhesion on PDMS surfaces placed in the oral cavity of five volunteers (the study was approved by the University Ethical Committee). After 24 h, the disks were analyzed using MTT assay and light microscopy. Results In the present pilot study, microwell structures were microfabricated on the PDMS surface via soft lithography with a spacing of 5 µm. Overall, bacterial adhesion did not significantly differ between the flat and micropatterned surfaces. However, individual analysis of two subjects showed greater bacterial adhesion on the micropatterned surfaces than on the flat surfaces. Significance Microfabrication and hMIRS might be implemented to study the cell/biomaterial interactions for dental materials. PMID:29593793

ADAM12 induction by Twist1 promotes tumor invasion and metastasis via regulation of invadopodia and focal adhesions

PubMed Central

Eckert, Mark A.; Santiago-Medina, Miguel; Lwin, Thinzar M.; Kim, Jihoon; Courtneidge, Sara A.

2017-01-01

ABSTRACT The Twist1 transcription factor promotes tumor invasion and metastasis by inducing epithelial–mesenchymal transition (EMT) and invadopodia-mediated extracellular matrix (ECM) degradation. The critical transcription targets of Twist1 for mediating these events remain to be uncovered. Here, we report that Twist1 strongly induces expression of a disintegrin and metalloproteinase 12 (ADAM12). We observed that the expression levels of Twist1 mRNA and ADAM12 mRNA are tightly correlated in human breast tumors. Knocking down ADAM12 blocked cell invasion in a 3D mammary organoid culture. Suppression of ADAM12 also inhibited Twist1-induced tumor invasion and metastasis in human breast tumor xenografts, without affecting primary tumor formation. Mechanistically, knockdown of ADAM12 in breast cancer cells significantly reduced invadopodia formation and matrix degradation, and simultaneously increased overall cell adhesion to the ECM. Live-imaging analysis showed that knockdown of ADAM12 significantly inhibited focal adhesion turnover. Mechanistically, both the disintegrin and metalloproteinase domains of ADAM12 are required for its function at invadopodia, whereas the metalloproteinase domain is dispensable for its function at focal adhesions. Taken together, these data suggest that ADAM12 plays a crucial role in tumor invasion and metastasis by regulating both invadopodia and focal adhesions. PMID:28468988

Neuron-like differentiation of mesenchymal stem cells on silicon nanowires

NASA Astrophysics Data System (ADS)

Kim, Hyunju; Kim, Ilsoo; Choi, Heon-Jin; Kim, So Yeon; Yang, Eun Gyeong

2015-10-01

The behavior of mammalian cells on vertical nanowire (NW) arrays, including cell spreading and the dynamic distribution of focal adhesions and cytoskeletal proteins, has been intensively studied to extend the implications for cellular manipulations in vitro. Prompted by the result that cells on silicon (Si) NWs showed morphological changes and reduced migration rates, we have explored the transition of mesenchymal stem cells into a neuronal lineage by using SiNWs with varying lengths. When human mesenchymal stem cells (hMSCs) were cultured on the longest SiNWs for 3 days, most of the cells exhibited elongated shapes with neurite-like extensions and dot-like focal adhesions that were prominently observed along with actin filaments. Under these circumstances, the cell motility analyzed by live cell imaging was found to decrease due to the presence of SiNWs. In addition, the slowed growth rate, as well as the reduced population of S phase cells, suggested that the cell cycle was likely arrested in response to the differentiation process. Furthermore, we measured the mRNA levels of several lineage-specific markers to confirm that the SiNWs actually induced neuron-like differentiation of the hMSCs while hampering their osteogenic differentiation. Taken together, our results implied that SiNWs were capable of inducing active reorganization of cellular behaviors, collectively guiding the fate of hMSCs into the neural lineage even in the absence of any inducing reagent.The behavior of mammalian cells on vertical nanowire (NW) arrays, including cell spreading and the dynamic distribution of focal adhesions and cytoskeletal proteins, has been intensively studied to extend the implications for cellular manipulations in vitro. Prompted by the result that cells on silicon (Si) NWs showed morphological changes and reduced migration rates, we have explored the transition of mesenchymal stem cells into a neuronal lineage by using SiNWs with varying lengths. When human mesenchymal stem cells (hMSCs) were cultured on the longest SiNWs for 3 days, most of the cells exhibited elongated shapes with neurite-like extensions and dot-like focal adhesions that were prominently observed along with actin filaments. Under these circumstances, the cell motility analyzed by live cell imaging was found to decrease due to the presence of SiNWs. In addition, the slowed growth rate, as well as the reduced population of S phase cells, suggested that the cell cycle was likely arrested in response to the differentiation process. Furthermore, we measured the mRNA levels of several lineage-specific markers to confirm that the SiNWs actually induced neuron-like differentiation of the hMSCs while hampering their osteogenic differentiation. Taken together, our results implied that SiNWs were capable of inducing active reorganization of cellular behaviors, collectively guiding the fate of hMSCs into the neural lineage even in the absence of any inducing reagent. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr05787f

The FAK–Arp2/3 interaction promotes leading edge advance and haptosensing by coupling nascent adhesions to lamellipodia actin

PubMed Central

Swaminathan, Vinay; Fischer, R. S.; Waterman, Clare M.

2016-01-01

Cell migration is initiated in response to biochemical or physical cues in the environment that promote actin-mediated lamellipodial protrusion followed by the formation of nascent integrin adhesions (NAs) within the protrusion to drive leading edge advance. Although FAK is known to be required for cell migration through effects on focal adhesions, its role in NA formation and lamellipodial dynamics is unclear. Live-cell microscopy of FAK−/− cells with expression of phosphorylation deficient or a FERM-domain mutant deficient in Arp2/3 binding revealed a requirement for FAK in promoting the dense formation, transient stabilization, and timely turnover of NA within lamellipodia to couple actin-driven protrusion to adhesion and advance of the leading edge. Phosphorylation on Y397 of FAK promotes dense NA formation but is dispensable for transient NA stabilization and leading edge advance. In contrast, transient NA stabilization and advance of the cell edge requires FAK–Arp2/3 interaction, which promotes Arp2/3 localization to NA and reduces FAK activity. Haptosensing of extracellular matrix (ECM) concentration during migration requires the interaction between FAK and Arp2/3, whereas FAK phosphorylation modulates mechanosensing of ECM stiffness during spreading. Taken together, our results show that mechanistically separable functions of FAK in NA are required for cells to distinguish distinct properties of their environment during migration. PMID:26842895

Mesenchymal stem cell interaction with ultra smooth nanostructured diamond for wear resistant orthopaedic implants

PubMed Central

Clem, William C.; Chowdhury, Shafiul; Catledge, Shane A.; Weimer, Jeffrey J.; Shaikh, Faheem M.; Hennessy, Kristin M.; Konovalov, Valery V.; Hill, Michael R.; Waterfeld, Alfred; Bellis, Susan L.; Vohra, Yogesh K.

2008-01-01

Ultra smooth nanostructured diamond (USND) can be applied to greatly increase the wear resistance of orthopaedic implants over conventional designs. Herein we describe surface modification techniques and cytocompatibility studies performed on this new material. We report that hydrogen (H) -terminated USND surfaces supported robust mesenchymal stem cell (MSC) adhesion and survival, while oxygen (O) and fluorine (F) -terminated surfaces resisted cell adhesion, indicating that USND can be modified to either promote or prevent cell/biomaterial interactions. Given the favorable cell response to H-terminated USND, this material was further compared with two commonly-used biocompatible metals, titanium alloy (Ti-6Al-4V) and cobalt chrome (CoCrMo). MSC adhesion and proliferation were significantly improved on USND compared with CoCrMo, although cell adhesion was greatest on Ti-6Al-4V. Comparable amounts of the proadhesive protein, fibronectin, were deposited from serum on the three substrates. Finally, MSCs were induced to undergo osteoblastic differentiation on the three materials, and deposition of a mineralized matrix was quantified. Similar amounts of mineral were deposited onto USND and CoCrMo, whereas mineral deposition was slightly higher on Ti-6Al-4V. When coupled with recently published wear studies, these in vitro results suggest that USND has the potential to reduce debris particle release from orthopaedic implants without compromising osseointegration. PMID:18490051

Downregulation of endothelial adhesion molecules by dimethylfumarate, but not monomethylfumarate, and impairment of dynamic lymphocyte-endothelial cell interactions.

PubMed

Wallbrecht, Katrin; Drick, Nora; Hund, Anna-Carina; Schön, Michael P

2011-12-01

Although fumaric acid esters (FAE) have a decade-long firm place in the therapeutic armamentarium for psoriasis, their pleiotropic mode of action is not yet fully understood. While most previous studies have focused on the effects of FAE on leucocytes, we have addressed their activity on macro- and microvascular endothelial cells. As detected both on mRNA and protein levels, dimethylfumarate effected a profound reduction of TNFα-induced expression of E-selectin (CD62E), ICAM-1 (CD54) and VCAM-1 (CD106) on two different endothelial cell populations in a concentration-dependent manner. This reduction of several endothelial adhesion molecules was accompanied by a dramatic diminution of both rolling and firm adhesive interactions between endothelial cells and lymphocytes in a dynamic flow chamber system. Dimethylfumarate, at a concentration of 50 μm, reduced lymphocyte rolling on endothelial cells by 85.9% (P<0.001 compared to untreated controls), and it diminished the number of adherent cells by 88% (P<0.001). In contrast, monomethylfumarate (MMF) influenced neither surface expression of adhesion molecules nor interactions between endothelial cells and lymphocytes. These observations demonstrate that endothelial cells, in addition to the known effects on leucocytes, undergo profound functional changes in response to dimethylfumarate. These changes are accompanied by severely impaired dynamic interactions with lymphocytes, which constitute the critical initial step of leucocyte recruitment to inflamed tissues in psoriasis and other TNF-related inflammatory disorders. © 2011 John Wiley & Sons A/S.

Glycosylation-dependent binding of galectin-8 to activated leukocyte cell adhesion molecule (ALCAM/CD166) promotes its surface segregation on breast cancer cells.

PubMed

Fernández, Marisa M; Ferragut, Fátima; Cárdenas Delgado, Víctor M; Bracalente, Candelaria; Bravo, Alicia I; Cagnoni, Alejandro J; Nuñez, Myriam; Morosi, Luciano G; Quinta, Héctor R; Espelt, María V; Troncoso, María F; Wolfenstein-Todel, Carlota; Mariño, Karina V; Malchiodi, Emilio L; Rabinovich, Gabriel A; Elola, María T

2016-10-01

We previously demonstrated that the activated leukocyte cell adhesion molecule (ALCAM/CD166) can interact with galectin-8 (Gal-8) in endothelial cells. ALCAM is a member of the immunoglobulin superfamily that promotes homophilic and heterophilic cell-cell interactions. Gal-8 is a "tandem-repeat"-type galectin, known as a matricellular protein involved in cell adhesion. Here, we analyzed the physical interaction between both molecules in breast cancer cells and the functional relevance of this phenomenon. We performed binding assays by surface plasmon resonance to study the interaction between Gal-8 and the recombinant glycosylated ALCAM ectodomain or endogenous ALCAM from MDA-MB-231 breast cancer cells. We also analyzed the binding of ALCAM-silenced or control breast cancer cells to immobilized Gal-8 by SPR. In internalization assays, we evaluated the influence of Gal-8 on ALCAM surface localization. We showed that recombinant glycosylated ALCAM and endogenous ALCAM from breast carcinoma cells physically interacted with Gal-8 in a glycosylation-dependent fashion displaying a differential behavior compared to non-glycosylated ALCAM. Moreover, ALCAM-silenced breast cancer cells exhibited reduced binding to Gal-8 relative to control cells. Importantly, exogenously added Gal-8 provoked ALCAM segregation, probably trapping this adhesion molecule at the surface of breast cancer cells. Our data indicate that Gal-8 interacts with ALCAM at the surface of breast cancer cells through glycosylation-dependent mechanisms. A novel heterophilic interaction between ALCAM and Gal-8 is demonstrated here, suggesting its physiologic relevance in the biology of breast cancer cells. Copyright © 2016 Elsevier B.V. All rights reserved.

N-glycosylation at the SynCAM (synaptic cell adhesion molecule) immunoglobulin interface modulates synaptic adhesion.

PubMed

Fogel, Adam I; Li, Yue; Giza, Joanna; Wang, Qing; Lam, Tukiet T; Modis, Yorgo; Biederer, Thomas

2010-11-05

Select adhesion molecules connect pre- and postsynaptic membranes and organize developing synapses. The regulation of these trans-synaptic interactions is an important neurobiological question. We have previously shown that the synaptic cell adhesion molecules (SynCAMs) 1 and 2 engage in homo- and heterophilic interactions and bridge the synaptic cleft to induce presynaptic terminals. Here, we demonstrate that site-specific N-glycosylation impacts the structure and function of adhesive SynCAM interactions. Through crystallographic analysis of SynCAM 2, we identified within the adhesive interface of its Ig1 domain an N-glycan on residue Asn(60). Structural modeling of the corresponding SynCAM 1 Ig1 domain indicates that its glycosylation sites Asn(70)/Asn(104) flank the binding interface of this domain. Mass spectrometric and mutational studies confirm and characterize the modification of these three sites. These site-specific N-glycans affect SynCAM adhesion yet act in a differential manner. Although glycosylation of SynCAM 2 at Asn(60) reduces adhesion, N-glycans at Asn(70)/Asn(104) of SynCAM 1 increase its interactions. The modification of SynCAM 1 with sialic acids contributes to the glycan-dependent strengthening of its binding. Functionally, N-glycosylation promotes the trans-synaptic interactions of SynCAM 1 and is required for synapse induction. These results demonstrate that N-glycosylation of SynCAM proteins differentially affects their binding interface and implicate post-translational modification as a mechanism to regulate trans-synaptic adhesion.

N-Glycosylation at the SynCAM (Synaptic Cell Adhesion Molecule) Immunoglobulin Interface Modulates Synaptic Adhesion*

PubMed Central

Fogel, Adam I.; Li, Yue; Giza, Joanna; Wang, Qing; Lam, TuKiet T.; Modis, Yorgo; Biederer, Thomas

2010-01-01

Select adhesion molecules connect pre- and postsynaptic membranes and organize developing synapses. The regulation of these trans-synaptic interactions is an important neurobiological question. We have previously shown that the synaptic cell adhesion molecules (SynCAMs) 1 and 2 engage in homo- and heterophilic interactions and bridge the synaptic cleft to induce presynaptic terminals. Here, we demonstrate that site-specific N-glycosylation impacts the structure and function of adhesive SynCAM interactions. Through crystallographic analysis of SynCAM 2, we identified within the adhesive interface of its Ig1 domain an N-glycan on residue Asn60. Structural modeling of the corresponding SynCAM 1 Ig1 domain indicates that its glycosylation sites Asn70/Asn104 flank the binding interface of this domain. Mass spectrometric and mutational studies confirm and characterize the modification of these three sites. These site-specific N-glycans affect SynCAM adhesion yet act in a differential manner. Although glycosylation of SynCAM 2 at Asn60 reduces adhesion, N-glycans at Asn70/Asn104 of SynCAM 1 increase its interactions. The modification of SynCAM 1 with sialic acids contributes to the glycan-dependent strengthening of its binding. Functionally, N-glycosylation promotes the trans-synaptic interactions of SynCAM 1 and is required for synapse induction. These results demonstrate that N-glycosylation of SynCAM proteins differentially affects their binding interface and implicate post-translational modification as a mechanism to regulate trans-synaptic adhesion. PMID:20739279

Integrins are required for tissue organization and restriction of neurogenesis in regenerating planarians

PubMed Central

Seebeck, Florian; März, Martin; Meyer, Anna-Wiebke; Reuter, Hanna; Vogg, Matthias C.; Stehling, Martin; Mildner, Karina; Zeuschner, Dagmar; Rabert, Franziska

2017-01-01

Tissue regeneration depends on proliferative cells and on cues that regulate cell division, differentiation, patterning and the restriction of these processes once regeneration is complete. In planarians, flatworms with high regenerative potential, muscle cells express some of these instructive cues. Here, we show that members of the integrin family of adhesion molecules are required for the integrity of regenerating tissues, including the musculature. Remarkably, in regenerating β1-integrin RNAi planarians, we detected increased numbers of mitotic cells and progenitor cell types, as well as a reduced ability of stem cells and lineage-restricted progenitor cells to accumulate at wound sites. These animals also formed ectopic spheroid structures of neural identity in regenerating heads. Interestingly, those polarized assemblies comprised a variety of neural cells and underwent continuous growth. Our study indicates that integrin-mediated cell adhesion is required for the regenerative formation of organized tissues and for restricting neurogenesis during planarian regeneration. PMID:28137894

Antitumor effects of the flavone chalcone: inhibition of invasion and migration through the FAK/JNK signaling pathway in human gastric adenocarcinoma AGS cells.

PubMed

Lin, Su-Hsuan; Shih, Yuan-Wei

2014-06-01

Chalcones (benzylideneacetophenone) are cancer-preventive food components found in a human diet rich in fruits and vegetables. In this study, we first report the chemopreventive effect of chalcone in human gastric adenocarcinoma cell lines: AGS. The results showed that chalcone could inhibit the abilities of the adhesion, invasion, and migration by cell-matrix adhesion assay, Boyden chamber invasion/migration assay, and wound-healing assay. Molecular data showed that the effect of chalcone in AGS cells might be mediated via sustained inactivation of the phosphorylation of focal adhesion kinase (FAK) and c-Jun N-terminal kinase 1 and 2 (JNK1/2) signal involved in the downregulation of the expressions of matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9). Next, chalcone-treated AGS cells showed tremendous decrease in the phosphorylation and degradation of inhibitor of kappaBα (IκBα), the nuclear level of NF-κB, and the binding ability of NF-κB to NF-κB response element. Furthermore, treating FAK small interfering RNA (FAK siRNA) and specific inhibitor for JNK (SP600125) to AGS cells could reduce the phosphorylation of JNK1/2 and the activity of MMP-2 and MMP-9. Our results revealed that chalcone significantly inhibited the metastatic ability of AGS cells by reducing MMP-2 and MMP-9 expressions concomitantly with a marked reduction on cell invasion and migration through suppressing and JNK signaling pathways. We suggest that chalcone may offer the application in clinical medicine.

Heterogeneity of Focal Adhesions and Focal Contacts in Motile Fibroblasts.

PubMed

Gladkikh, Aleena; Kovaleva, Anastasia; Tvorogova, Anna; Vorobjev, Ivan A

2018-01-01

Cell-extracellular matrix (ECM) adhesion is an important property of virtually all cells in multicellular organisms. Cell-ECM adhesion studies, therefore, are very significant both for biology and medicine. Over the last three decades, biomedical studies resulted in a tremendous advance in our understanding of the molecular basis and functions of cell-ECM adhesion. Based on morphological and molecular criteria, several different types of model cell-ECM adhesion structures including focal adhesions, focal complexes, fibrillar adhesions, podosomes, and three-dimensional matrix adhesions have been described. All the subcellular structures that mediate cell-ECM adhesion are quite heterogeneous, often varying in size, shape, distribution, dynamics, and, to a certain extent, molecular constituents. The morphological "plasticity" of cell-ECM adhesion perhaps reflects the needs of cells to sense, adapt, and respond to a variety of extracellular environments. In addition, cell type (e.g., differentiation status, oncogenic transformation, etc.) often exerts marked influence on the structure of cell-ECM adhesions. Although molecular, genetic, biochemical, and structural studies provide important maps or "snapshots" of cell-ECM adhesions, the area of research that is equally valuable is to study the heterogeneity of FA subpopulations within cells. Recently time-lapse observations on the FA dynamics become feasible, and behavior of individual FA gives additional information on cell-ECM interactions. Here we describe a robust method of labeling of FA using plasmids with fluorescent markers for paxillin and vinculin and quantifying the morphological and dynamical parameters of FA.

Activated Leukocyte Cell Adhesion Molecule Expression and Shedding in Thyroid Tumors

PubMed Central

Miccichè, Francesca; Da Riva, Luca; Fabbi, Marina; Pilotti, Silvana; Mondellini, Piera; Ferrini, Silvano; Canevari, Silvana; Pierotti, Marco A.; Bongarzone, Italia

2011-01-01

Activated leukocyte cell adhesion molecule (ALCAM, CD166) is expressed in various tissues, cancers, and cancer-initiating cells. Alterations in expression of ALCAM have been reported in several human tumors, and cell adhesion functions have been proposed to explain its association with cancer. Here we documented high levels of ALCAM expression in human thyroid tumors and cell lines. Through proteomic characterization of ALCAM expression in the human papillary thyroid carcinoma cell line TPC-1, we identified the presence of a full-length membrane-associated isoform in cell lysate and of soluble ALCAM isoforms in conditioned medium. This finding is consistent with proteolytically shed ALCAM ectodomains. Nonspecific agents, such as phorbol myristate acetate (PMA) or ionomycin, provoked increased ectodomain shedding. Epidermal growth factor receptor stimulation also enhanced ALCAM secretion through an ADAM17/TACE-dependent pathway. ADAM17/TACE was expressed in the TPC-1 cell line, and ADAM17/TACE silencing by specific small interfering RNAs reduced ALCAM shedding. In addition, the CGS27023A inhibitor of ADAM17/TACE function reduced ALCAM release in a dose-dependent manner and inhibited cell migration in a wound-healing assay. We also provide evidence for the existence of novel O-glycosylated forms and of a novel 60-kDa soluble form of ALCAM, which is particularly abundant following cell stimulation by PMA. ALCAM expression in papillary and medullary thyroid cancer specimens and in the surrounding non-tumoral component was studied by western blot and immunohistochemistry, with results demonstrating that tumor cells overexpress ALCAM. These findings strongly suggest the possibility that ALCAM may have an important role in thyroid tumor biology. PMID:21364949

Estrogen and pure antiestrogen fulvestrant (ICI 182 780) augment cell-matrigel adhesion of MCF-7 breast cancer cells through a novel G protein coupled estrogen receptor (GPR30)-to-calpain signaling axis.

PubMed

Chen, Yan; Li, Zheng; He, Yan; Shang, Dandan; Pan, Jigang; Wang, Hongmei; Chen, Huamei; Zhu, Zhuxia; Wan, Lei; Wang, Xudong

2014-03-01

Fulvestrant (ICI 182 780, ICI) has been used in treating patients with hormone-sensitive breast cancer, yet initial or acquired resistance to endocrine therapies frequently arises and, in particular, cancer recurs as metastasis. We demonstrate here that both 17-beta-estradiol (E2) and ICI enhance cell adhesion to matrigel in MCF-7 breast cancer cells, with increased autolysis of calpain 1 (large subunit) and proteolysis of focal adhesion kinase (FAK), indicating calpain activation. Additionally, either E2 or ICI induced down-regulation of estrogen receptor α without affecting G protein coupled estrogen receptor 30 (GPR30) expression. Interestingly, GPR30 agonist G1 triggered calpain 1 autolysis but not calpain 2, whereas ER agonist diethylstilbestrol caused no apparent calpain autolysis. Furthermore, the actions of E2 and ICI on calpain and cell adhesion were tremendously suppressed by G15, or knockdown of GPR30. E2 and ICI also induced phosphorylation of extracellular regulated protein kinases 1 and 2 (ERK1/2), and suppression of ERK1/2 phosphorylation by U0126 profoundly impeded calpain activation triggered by estrogenic and antiestrogenic stimulations indicating implication of ERK1/2 in the GPR30-mediated action. Lastly, the E2- or ICI-induced cell adhesion was dramatically impaired by calpain-specific inhibitors, ALLN or calpeptin, suggesting requirement of calpain in the GPR30-associated action. These data show that enhanced cell adhesion by E2 and ICI occurs via a novel GPR30-ERK1/2-calpain pathway. Our results indicate that targeting the GPR30 signaling may be a potential strategy to reduce metastasis and improve the efficacy of antiestrogens in treatment of advanced breast cancer. Copyright © 2014 Elsevier Inc. All rights reserved.

Biocompatibility study of lithium disilicate and zirconium oxide ceramics for esthetic dental abutments

PubMed Central

2016-01-01

Purpose The increasing demand for esthetically pleasing results has contributed to the use of ceramics for dental implant abutments. The aim of this study was to compare the biological response of epithelial tissue cultivated on lithium disilicate (LS2) and zirconium oxide (ZrO2) ceramics. Understanding the relevant physicochemical and mechanical properties of these ceramics will help identify the optimal material for facilitating gingival wound closure. Methods Both biomaterials were prepared with 2 different surface treatments: raw and polished. Their physicochemical characteristics were analyzed by contact angle measurements, scanning white-light interferometry, and scanning electron microscopy. An organotypic culture was then performed using a chicken epithelium model to simulate peri-implant soft tissue. We measured the contact angle, hydrophobicity, and roughness of the materials as well as the tissue behavior at their surfaces (cell migration and cell adhesion). Results The best cell migration was observed on ZrO2 ceramic. Cell adhesion was also drastically lower on the polished ZrO2 ceramic than on both the raw and polished LS2. Evaluating various surface topographies of LS2 showed that increasing surface roughness improved cell adhesion, leading to an increase of up to 13%. Conclusions Our results demonstrate that a biomaterial, here LS2, can be modified using simple surface changes in order to finely modulate soft tissue adhesion. Strong adhesion at the abutment associated with weak migration assists in gingival wound healing. On the same material, polishing can reduce cell adhesion without drastically modifying cell migration. A comparison of LS2 and ZrO2 ceramic showed that LS2 was more conducive to creating varying tissue reactions. Our results can help dental surgeons to choose, especially for esthetic implant abutments, the most appropriate biomaterial as well as the most appropriate surface treatment to use in accordance with specific clinical dental applications. PMID:28050314

A recombinant tail-less integrin beta 4 subunit disrupts hemidesmosomes, but does not suppress alpha 6 beta 4-mediated cell adhesion to laminins

PubMed Central

1995-01-01

To examine the function of the alpha 6 beta 4 integrin we have determined its ligand-binding ability and overexpressed two potentially dominant negative mutant beta 4 subunits, lacking either the cytoplasmic or extracellular domain, in bladder epithelial 804G cells. The results of cell adhesion and radioligand-binding assays showed that alpha 6 beta 4 is a receptor for several laminin isoforms, including laminin 1, 2, 4, and 5. Overexpression of the tail-less or head-less mutant beta 4 subunit did not suppress alpha 6 beta 4-mediated adhesion to laminins, as both types of transfectants adhered to these ligands in the presence of blocking anti-beta 1 antibodies as well as the controls. However, immunofluorescence experiments indicated that the endogenous alpha 6 beta 4 integrin and other hemidesmosomal markers were not concentrated in hemidesmosomes in cells overexpressing tail- less beta 4, while the distribution of these molecules was not altered in cells overexpressing the head-less subunit. Electron microscopic studies confirmed that cells overexpressing tail-less beta 4 had a drastically reduced number of hemidesmosomes, while cells expressing the head-less subunit had a normal number of these structures. Thus, expression of a tail-less, but not a head-less mutant beta 4 subunit leads to a dominant negative effect on hemidesmosome assembly without suppressing initial adhesion to laminins. We conclude that the alpha 6 beta 4 integrin binds to several laminins and plays an essential role in the assembly and/or stability of hemidesmosomes, that alpha 6 beta 4- mediated adhesion and hemidesmosome assembly have distinct requirements, and that it is possible to use a dominant negative approach to selectively interfere with a specific function of an integrin. PMID:7721947

Rac-WAVE-mediated actin reorganization is required for organization and maintenance of cell-cell adhesion.

PubMed

Yamazaki, Daisuke; Oikawa, Tsukasa; Takenawa, Tadaomi

2007-01-01

During cadherin-dependent cell-cell adhesion, the actin cytoskeleton undergoes dynamic reorganization in epithelial cells. Rho-family small GTPases, which regulate actin dynamics, play pivotal roles in cadherin-dependent cell-cell adhesion; however, the precise molecular mechanisms that underlie cell-cell adhesion formation remain unclear. Here we show that Wiskott-Aldrich syndrome protein family verprolin-homologous protein (WAVE)-mediated reorganization of actin, downstream of Rac plays an important role in normal development of cadherin-dependent cell-cell adhesions in MDCK cells. Rac-induced development of cadherin-dependent adhesions required WAVE2-dependent actin reorganization. The process of cell-cell adhesion is divided into three steps: formation of new cell-cell contacts, stabilization of these new contacts and junction maturation. WAVE1 and WAVE2 were expressed in MDCK cells. The functions of WAVE1 and WAVE2 were redundant in this system but WAVE2 appeared to play a more significant role. During the first step, WAVE2-dependent lamellipodial protrusions facilitated formation of cell-cell contacts. During the second step, WAVE2 recruited actin filaments to new cell-cell contacts and stabilized newly formed cadherin clusters. During the third step, WAVE2-dependent actin reorganization was required for organization and maintenance of mature cell-cell adhesions. Thus, Rac-WAVE-dependent actin reorganization is not only involved in formation of cell-cell adhesions but is also required for their maintenance.

Overexpression of Activin Receptor-like Kinase 7 in Breast Cancer Cells Is Associated with Decreased Cell Growth and Adhesion.

PubMed

Hu, Tingting; Su, Fengxi; Jiang, Wenguo; Dart, D Alwyn

2017-07-01

To examine the expression and function of activin receptor-like kinase 7 (ALK7) in breast cancer, its association with disease prognosis, and its impact on breast cancer cell function. A cohort of patients with breast cancer were examined for ALK7 expression in association with pathological and clinical aspects. In vitro cell assays of ALK7 were investigated using an expression plasmid. Overall higher levels of ALK7 transcripts were seen in the breast cancer samples vs. normal tissue. However, within the cancer cohort, lower levels of ALK7 transcript were associated with poor prognosis. Patients with lower expression of ALK7 also had shorter survival. Overexpression of ALK7 reduced proliferation and adhesion of breast cancer cells in vitro. We found that overexpressed ALK7 had complex effects on the MCF-7 cell sensitivity to chemotherapy drugs. Decreased expression of ALK7 in breast cancer is correlated with poor prognosis. ALK7 is a negative regulator of adhesion and proliferation of breast cancer cells. This suggests that ALK7 is a potential tumor suppressor in breast cancer. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

Effect of streptavidin-biotin on endothelial vasoregulation and leukocyte adhesion.

PubMed

Chan, Bernard P; Reichert, William M; Truskey, George A

2004-08-01

The current study examines whether the adhesion promoting arginine-glycine-aspartate-streptavidin mutant (RGD-SA) also affects two important endothelial cell (EC) functions in vitro: vasoregulation and leukocyte adhesion. EC adherent to surfaces via fibronectin (Fn) or Fn plus RGD-SA were subjected to laminar shear flow and media samples were collected over a period of 4h to measure the concentration of nitric oxide (NO), prostacyclin (PGI(2)), and endothelin-1 (ET-1). Western blot analysis was used to quantify the levels of endothelial-derived nitric oxide synthase (eNOS) and cyclooxygenase II (COX II). In a separate set of experiments, fluorescent polymorphonuclear leukocyte (PMN) adhesion to EC was quantified for EC with and without exposure to flow preconditioning. When cell adhesion was supplemented with the SA-biotin system, flow-induced production of NO and PGI(2) increased significantly relative to cells adherent on Fn alone. Previous exposure of EC to shear flow also significantly decreased PMN attachment to SA-biotin supplemented EC, but only after 2h of exposure to shear flow. The observed decrease in PMN-EC adhesion was negated by NG-nitro-L-arginine methyl ester (L-NAME), an antagonist of NO synthesis, but not by indomethacin, an inhibitor to PGI(2) synthesis, indicating the induced effect of PMN-EC interaction is primarily NO-dependent. Results from this study suggest that the use of SA-biotin to supplement EC adhesion encourages vasodilation and PMN adhesion in vitro under physiological shear-stress conditions. We postulate that the presence of SA-biotin more efficiently transmits the shear-stress signal and amplifies the downstream events including the NO and PGI(2) release and leukocyte-EC inhibition. These results may have ramifications for reducing thrombus-induced vascular graft failure.

Changes in E-cadherin rigidity sensing regulate cell adhesion

PubMed Central

Collins, Caitlin; Pruitt, Beth L.; Nelson, W. James

2017-01-01

Mechanical cues are sensed and transduced by cell adhesion complexes to regulate diverse cell behaviors. Extracellular matrix (ECM) rigidity sensing by integrin adhesions has been well studied, but rigidity sensing by cadherins during cell adhesion is largely unexplored. Using mechanically tunable polyacrylamide (PA) gels functionalized with the extracellular domain of E-cadherin (Ecad-Fc), we showed that E-cadherin–dependent epithelial cell adhesion was sensitive to changes in PA gel elastic modulus that produced striking differences in cell morphology, actin organization, and membrane dynamics. Traction force microscopy (TFM) revealed that cells produced the greatest tractions at the cell periphery, where distinct types of actin-based membrane protrusions formed. Cells responded to substrate rigidity by reorganizing the distribution and size of high-traction-stress regions at the cell periphery. Differences in adhesion and protrusion dynamics were mediated by balancing the activities of specific signaling molecules. Cell adhesion to a 30-kPa Ecad-Fc PA gel required Cdc42- and formin-dependent filopodia formation, whereas adhesion to a 60-kPa Ecad-Fc PA gel induced Arp2/3-dependent lamellipodial protrusions. A quantitative 3D cell–cell adhesion assay and live cell imaging of cell–cell contact formation revealed that inhibition of Cdc42, formin, and Arp2/3 activities blocked the initiation, but not the maintenance of established cell–cell adhesions. These results indicate that the same signaling molecules activated by E-cadherin rigidity sensing on PA gels contribute to actin organization and membrane dynamics during cell–cell adhesion. We hypothesize that a transition in the stiffness of E-cadherin homotypic interactions regulates actin and membrane dynamics during initial stages of cell–cell adhesion. PMID:28674019

Increasing levels of estradiol are deleterious to embryonic implantation because they directly affect the embryo.

PubMed

Valbuena, D; Martin, J; de Pablo, J L; Remohí, J; Pellicer, A; Simón, C

2001-11-01

To investigate whether the deleterious effect of E(2) on embryonic implantation is due to a direct effect on the endometrium, on the embryo, or both. Prospective, controlled in vitro study. Tertiary infertility center. Fertile patients in the luteal phase with histologically normal endometrium who were attending the infertility clinic as oocyte donors (n = 14). E(2) dose-response (0, 10(-8), 10(-7), 10(-6), 10(-5), and 10(-4) M) and time course (day 2 vs. day 5) experiments were performed in an in vitro embryo adhesion assay composed of human polarized endometrial epithelial cells obtained from fertile patients and mouse embryos. Blastocyst formation rate and embryo adhesion rate. Monolayers of polarized endometrial epithelial cells expressed ERalpha at the mRNA level. The E(2) dose response of blastocysts with polarized endometrial epithelial cells (n = 235) demonstrated a progressive reduction in embryonic adhesion that was statistically significant at 10(-6) M. When polarized endometrial epithelial cells were treated alone with increasing doses of E(2) for 3 days and E(2) was then removed and blastocysts added (n = 410), embryonic adhesion was not significantly reduced, except at 10(-4) M. When 2-day mouse embryos (n = 609) were treated with increasing E(2) concentrations until day 5, the rate of blastocyst formation significantly decreased at a concentration >or= 10(-6) M, and embryonic adhesion decreased when blastocysts (n = 400) were obtained at a concentration >or= 10(-7) M. Time course experiments of embryos cultured for 2 days with polarized endometrial epithelial cells (n = 426) showed that the adhesion rate was higher at E(2) levels of 10(-7), 10(-6) and 10(-5) M compared with embryos cultured for 5 days (n = 495). High E(2) levels are deleterious to embryo adhesion in vitro, mainly because they have a direct toxic effect on the embryo that may occur at the cleavage stage.

Multifunctional effect of epigallocatechin-3-gallate (EGCG) in downregulation of gelatinase-A (MMP-2) in human breast cancer cell line MCF-7.

PubMed

Sen, Triparna; Moulik, Shuvojit; Dutta, Anindita; Choudhury, Paromita Roy; Banerji, Aniruddha; Das, Shamik; Roy, Madhumita; Chatterjee, Amitava

2009-02-13

The tumor inhibiting property of green tea polyphenol epigallocatechin-3-gallate (EGCG) is well documented. Studies reveal that matrix-metalloproteinases (MMPs) play pivotal roles in tumor invasion through degradation of basement membranes and extracellular matrix (ECM). We studied the effect of EGCG on matrixmetalloproteinases-2 (MMP-2), the factors involved in activation, secretion and signaling molecules that might be involved in the regulation of MMP-2 in human breast cancer cell line, MCF-7. MCF-7 was treated with EGCG (20 muM, 24 h), the effect of EGCG on MMP-2 expression, activity and its regulatory molecules were studied by gelatin zymography, Western blot, quantitative and semi-quantitative real time RT-PCR, immunoflourescence and cell adhesion assay. EGCG treatment reduced the activity, protein expression and mRNA expression level of MMP-2. EGCG treatment reduced the expression of focal adhesion kinase (FAK), membrane type-1-matrix metalloproteinase (MT1-MMP), nuclear factor-kappa B (NF-kB), vascular endothelial growth factor (VEGF) and reduced the adhesion of MCF-7 cells to ECM, fibronectin and vitronectin. Real time RT-PCR revealed a reduced expression of integrin receptors alpha5, beta1, alphav and beta3 due to EGCG treatment. Down regulation of expression of MT1-MMP, NF-kB, VEGF and disruption of functional status of integrin receptors may indicate decreased MMP-2 activation; low levels of FAK expression might indicate disruption in FAK-induced MMP-2 secretion and decrease in activation of phosphatidyl-inositol-3-kinase (PI-3K), extracellular regulated kinase (ERK) indicates probable hindrance in MMP-2 regulation and induction. We propose EGCG as potential inhibitor of expression and activity of pro-MMP-2 by a process involving multiple regulatory molecules in MCF-7.

Reduced endothelial activation after exercise is associated with improved HbA1c in patients with type 2 diabetes and coronary artery disease.

PubMed

Byrkjeland, Rune; Njerve, Ida U; Arnesen, Harald; Seljeflot, Ingebjørg; Solheim, Svein

2017-03-01

We have previously reported insignificant changes in HbA 1c after exercise in patients with both type 2 diabetes and coronary artery disease. In this study, we investigated the effect of exercise on endothelial function and possible associations between changes in endothelial function and HbA 1c . Patients with type 2 diabetes and coronary artery disease ( n = 137) were randomised to 12 months exercise or standard follow-up. Endothelial function was assessed by circulating biomarkers (E-selectin, intercellular adhesion molecule-1, vascular cell adhesion molecule-1, von Willebrand factor, tissue plasminogen activator antigen, asymmetric dimethylarginine and L-arginine/asymmetric dimethylarginine ratio). Differences between the randomised groups were analysed by analysis of covariance and correlations by Spearman's rho or Pearson's correlation. No effect of exercise on endothelial function was demonstrated. The changes in HbA 1c in the exercise group correlated with changes in E-selectin ( r = 0.56, p < 0.001), intercellular adhesion molecule-1 ( r = 0.27, p = 0.052), vascular cell adhesion molecule-1 ( r = 0.32, p = 0.022) and tissue plasminogen activator antigen ( r = 0.35, p =  0.011). HbA 1c decreased significantly more in patients with versus without a concomitant reduction in E-selectin ( p =  0.002), intercellular adhesion molecule-1 ( p =  0.011), vascular cell adhesion molecule-1 ( p =  0.028) and tissue plasminogen activator antigen ( p =  0.009). Exercise did not affect biomarkers of endothelial function in patients with both type 2 diabetes and coronary artery disease. However, changes in biomarkers of endothelial activation correlated with changes in HbA 1c , and reduced endothelial activation was associated with improved HbA 1c after exercise.

Quantitative comparison of cancer and normal cell adhesion using organosilane monolayer templates: an experimental study on the anti-adhesion effect of green-tea catechins.

PubMed

Sakamoto, Rumi; Kakinuma, Eisuke; Masuda, Kentaro; Takeuchi, Yuko; Ito, Kosaku; Iketaki, Kentaro; Matsuzaki, Takahisa; Nakabayashi, Seiichiro; Yoshikawa, Hiroshi Y; Yamamoto, Hideaki; Sato, Yuko; Tanii, Takashi

2016-09-01

The main constituent of green tea, (-)-Epigallocatechin-3-O-gallate (EGCG), is known to have cancer-specific chemopreventive effects. In the present work, we investigated how EGCG suppresses cell adhesion by comparing the adhesion of human pancreatic cancer cells (AsPC-1 and BxPC-3) and their counterpart, normal human embryonic pancreas-derived cells (1C3D3), in catechin-containing media using organosilane monolayer templates (OMTs). The purpose of this work is (1) to evaluate the quantitativeness in the measurement of cell adhesion with the OMT and (2) to show how green-tea catechins suppress cell adhesion in a cancer-specific manner. For the first purpose, the adhesion of cancer and normal cells was compared using the OMT. The cell adhesion in different type of catechins such as EGCG, (-)-Epicatechin-3-O-gallate (ECG) and (-)-Epicatechin (EC) was also evaluated. The measurements revealed that the anti-adhesion effect of green-tea catechins is cancer-specific, and the order is EGCG≫ECG>EC. The results agree well with the data reported to date, showing the quantitativeness of the new method. For the second purpose, the contact area of cells on the OMT was measured by reflection interference contrast microscopy. The cell-OMT contact area of cancer cells decreases with increasing EGCG concentration, whereas that of normal cells remains constant. The results reveal a twofold action of EGCG on cancer cell adhesion-suppressing cell attachment to a candidate adhesion site and decreasing the contact area of the cells-and validates the use of OMT as a tool for screening cancer cell adhesion.

Sulforaphane reduces vascular inflammation in mice and prevents TNF-α-induced monocyte adhesion to primary endothelial cells through interfering with the NF-κB pathway

PubMed Central

Nallasamy, Palanisamy; Si, Hongwei; Babu, Pon Velayutham Anandh; Pan, Dengke; Fu, Yu; Brooke, Elizabeth A.S.; Shah, Halley; Zhen, Wei; Zhu, Hong; Liu, Dongmin; Li, Yunbo; Jia, Zhenquan

2014-01-01

Sulforaphane, a naturally-occurring isothiocyanate present in cruciferous vegetables, has received wide attention for its potential to improve vascular function in vitro. However, its effect in vivo and the molecular mechanism of sulforaphane at physiological concentrations remain unclear. Here, we report that a sulforaphane concentration as low as 0.5 μM significantly inhibited TNF-α-induced adhesion of monocytes to human umbilical vein endothelial cells (HUVECs), a key event in the pathogenesis of atherosclerosis both in static and under flow conditions. Such physiological concentrations of sulforaphane also significantly suppressed TNF-α-induced production of monocyte chemotactic protein-1 (MCP-1), adhesion molecule sVCAM-1 and sE-Selectin, key mediators in the regulation of enhanced endothelial cell-monocyte interaction. Furthermore, sulforaphane inhibited TNF-α-induced NF-κB transcriptional activity, IκBα degradation and subsequent NF-κB p65 nuclear translocation in endothelial cells, suggesting that sulforaphane can inhibit inflammation by suppressing NF-κB signaling. In an animal study, sulforaphane (300 ppm) in a mouse diet significantly abolished TNF-α-increased ex vivo monocyte adhesion and circulating adhesion molecules and chemokines in C57BL/6 mice. Histology showed that sulforaphane treatment significantly prevented the eruption of endothelial lining in the intima layer of the aorta and preserved elastin fibers’ delicate organization as shown by Verhoeff-van Gieson staining. Immunohistochemistry studies showed that sulforaphane treatment also reduced VCAM-1 and monocytes-derived F4/80-positive macrophages in the aorta of TNF-α-treated mice. In conclusion, sulforaphane at physiological concentrations protects against TNF-α-induced vascular endothelial inflammation, in both in vitro and in vivo models. This anti-inflammatory effect of sulforaphane may be, at least in part, associated with interfering with the NF-κB pathway. PMID:24880493

Anti-adhesion activity of thyme (Thymus vulgaris L.) extract, thyme post-distillation waste, and olive (Olea europea L.) leaf extract against Campylobacter jejuni on polystyrene and intestine epithelial cells.

PubMed

Šikić Pogačar, Maja; Klančnik, Anja; Bucar, Franz; Langerholc, Tomaž; Smole Možina, Sonja

2016-06-01

In order to survive in food-processing environments and cause disease, Campylobacter jejuni requires specific survival mechanisms, such as biofilms, which contribute to its transmission through the food chain to the human host and present a critical form of resistance to a wide variety of antimicrobials. Phytochemical analysis of thyme ethanolic extract (TE), thyme post-hydrodistillation residue (TE-R), and olive leaf extract (OE) using high-performance liquid chromatography with photodiode array indicates that the major compounds in TE and TE-R are flavone glucuronides and rosmarinic acid derivatives, and in OE verbascoside, luteolin 7-O-glucoside and oleuroside. TE and TE-R reduced C. jejuni adhesion to abiotic surfaces by up to 30% at 0.2-12.5 µg mL(-1) , with TE-R showing a greater effect. OE from 3.125 to 200 µg mL(-1) reduced C. jejuni adhesion to polystyrene by 10-23%. On the other hand, C. jejuni adhesion to PSI cl1 cells was inhibited by almost 30% over a large concentration range of these extracts. Our findings suggest that TE, the agro-food waste material TE-R, and the by-product OE represent sources of bioactive phytochemicals that are effective at low concentrations and can be used as therapeutic agents to prevent bacterial adhesion. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

Leonurine protects against tumor necrosis factor-α-mediated inflammation in human umbilical vein endothelial cells.

PubMed

Liu, Xinhua; Pan, Lilong; Wang, Xianli; Gong, Qihai; Zhu, Yi Zhun

2012-05-01

Leonurine, a bioactive alkaloid compound in Herba leonuri, has various pharmacological activities, including antioxidant and anti-apoptotic capacities. This study was conducted to test the hypothesis that leonurine was able to attenuate tumor necrosis factor (TNF)-α-induced human umbilical vein endothelial cells (HUVEC) activation and the underlying molecular mechanisms. Mitogen-activated protein kinases (MAPK) activation, nuclear factor-κB (NF-κB) activation, and inflammatory mediators expression were detected by Western blot or enzyme-liked immunosorbent assay, intracellular reactive oxygen species (ROS) and NF-κB p65 translocation were measured by immunofluorescence, endothelial cell-monocyte interaction was detected by microscope. Leonurine inhibited U937 cells adhesion to TNF-α-activated HUVEC in a concentration dependent manner. Treatment with leonurine blocked TNF-α-induced mRNA and protein expression of adhesion molecules (intercellular adhesion molecule-1 and vascular cell adhesion molecule-1), cyclooxygenase-2, and monocyte chemoattractant protein-1 in endothelial cells. In addition, leonurine attenuated TNF-α-induced intracellular ROS production in HUVEC. Furthermore, leonurine also suppressed the TNF-α-activated p38 phosphorylation and IκBα degradation. Subsequently, reduced NF-κB p65 phosphorylation, nuclear translocation, and DNA-binding activity were also observed. Our results demonstrated for the first time that the anti-inflammatory properties of leonurine in endothelial cells, at least in part, through suppression of NF-κB activation, which may have a potential therapeutic use for inflammatory vascular diseases. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Modulating macrophage response to biomaterials

NASA Astrophysics Data System (ADS)

Zaveri, Toral

Macrophages recruited to the site of biomaterial implantation are the primary mediators of the chronic foreign body response to implanted materials. Since foreign body response limits performance and functional life of numerous implanted biomaterials/medical devices, various approaches have been investigated to modulate macrophage interactions with biomaterial surfaces to mitigate this response. In this work we have explored two independent approaches to modulate the macrophage inflammatory response to biomaterials. The first approach targets surface integrins, cell surface receptors that mediate cell adhesion to biomaterials through adhesive proteins spontaneously adsorbed on biomaterial surfaces. The second approach involves surface modification of biomaterials using nanotopographic features since nanotopography has been reported to modulate cell adhesion and viability in a cell type-dependent manner. More specifically, Zinc Oxide (ZnO) nanorod surface was investigated for its role in modulating macrophage adhesion and survival in vitro and foreign body response in vivo. For the first approach, we have investigated the role of integrin Mac-1 and RGD-binding integrins in the in-vivo osteolysis response and macrophage inflammatory processes of phagocytosis as well as inflammatory cytokine secretion in response to particulate biomaterials. We have also investigated the in vivo foreign body response (FBR) to subcutaneously implanted biomaterials by evaluating the thickness of fibrous capsule formed around the implants after 2 weeks of implantation. The role of Mac-1 integrin was isolated using a Mac-1 KO mouse and comparing it to a WT control. The role of RGD binding integrins in FBR was investigated by coating the implanted biomaterial with ELVAX(TM) polymer loaded with Echistatin which contains the RGD sequence. For the in-vivo osteolysis study and to study the in-vitro macrophage response to particulate biomaterials, we used the RGD peptide encapsulated in ELVAX(TM) and dissolved in macrophage media respectively. By studying the phagocytosis, inflammatory and FBR of macrophages from integrin knockout mice, as well as using various integrin blocking techniques we aim to identify the role of various integrins in macrophage inflammatory response. These integrins can serve as therapeutic targets for mitigating this inflammatory response and improve functional life of implanted biomaterials. Zinc oxide (ZnO) has been investigated in a number of biomedical applications and surfaces presenting well-controlled nanorod structures of ZnO have recently been developed. In order to investigate the influence of nanotopography on macrophage adhesive response, we evaluated macrophage adhesion and viability on ZnO nanorods, compared to a relatively flat sputtered ZnO controls and using glass substrates for reference. We found that although macrophages are capable of initially adhering to and spreading on ZnO nanorod substrates, the number of adherent macrophages on ZnO nanorods was reduced compared to ZnO flat substrate and glass. While these data suggest nanotopography may modulate macrophage adhesion, reduced cell viability on both sputtered and nanorod ZnO substrate indicates appreciable toxicity associated with ZnO. In order to determine long-term physiological responses, ZnO nanorodcoated and sputtered ZnO-coated polyethylene terephthalate (PET) discs were implanted subcutaneously in mice for 14 days. Upon implantation, both ZnO-coated discs resulted in a discontinuous cellular fibrous capsule indicative of unresolved inflammation, in contrast to uncoated PET discs, which resulted in typical foreign body capsule formation. Hence although ZnO substrates presenting nanorod topography have previously been shown to modulate cellular adhesion in a topography-dependent fashion for specific cell types, this work demonstrates that for primary murine macrophages, cell adhesion and viability correlate to both nanotopography and toxicity of dissolved Zn, parameters which are likely interdependent. Considering the toxicity of ZnO nanorod surface towards macrophages, their role as an antibacterial surface was explored. Antibacterial coating approaches are being investigated to modify implants to reduce bacterial adhesion and viability in order to reduce implant-associated infection. To assess the efficacy of ZnO nanorod surfaces as an anti-bacterial coating, we evaluated bacterial adhesion and viability, compared to sputtered ZnO and glass substrates. Common implant-associated pathogens, Pseudomonas aeruginosa and Staphylococcus epidermidis were investigated. ZnO nanorod surface and sputtered ZnO demonstrated a significant bactericidal effect, killing respectively 2.5x and 1.7x times the number of bacteria dead on glass. A similar bactericidal effect of ZnO substrates on S. epidermidis was also evident, with sputtered ZnO and ZnO nanorod substrates killing respectively 22x and 32x times bacteria dead on glass. These data support the further investigation of ZnO nanorod coatings for bacterial adhesion resistance and bactericidal properties.

GPR55 promotes migration and adhesion of colon cancer cells indicating a role in metastasis

PubMed Central

Andersen, L; Hasenöhrl, C; Feuersinger, D; Stančić, A; Fauland, A; Magnes, C; El‐Heliebi, A; Lax, S; Uranitsch, S; Haybaeck, J; Heinemann, A

2015-01-01

Background and Purpose Tumour cell migration and adhesion constitute essential features of metastasis. G‐protein coupled receptor 55 (GPR55), a lysophospholipid receptor, has been shown to play an important role in carcinogenesis. Here, we investigated the involvement of GPR55 in migration and metastasis of colon cancer cells. Experimental Approach Adhesion and migration assays using the highly metastatic colon cancer cell line HCT116 and an in vivo assay of liver metastasis were performed. The GPR55 antagonist CID16020046, cannabidiol, a putative GPR55 antagonist and GPR55 siRNA were used to block GPR55 activity in HCT116 colon cancer cells. Key Results HCT116 cells showed a significant decrease in adhesion to endothelial cells and in migration after blockade with CID16020046 or cannabidiol. The inhibitory effects of CID16020046 or cannabidiol were averted by GPR55 siRNA knock down in cancer cells. The integrity of endothelial cell monolayers was increased after pretreatment of HCT116 cells with the antagonists or after GPR55 siRNA knockdown while pretreatment with lysophosphatidylinositol (LPI), the endogenous ligand of GPR55, decreased integrity of the monolayers. LPI also induced migration in GPR55 overexpressing HCT116 cells that was blocked by GPR55 antagonists. In a mouse model of metastasis, the arrest of HCT116 cancer cells in the liver was reduced after treatment with CID16020046 or cannabidiol. Increased levels of LPI (18:0) were found in colon cancer patients when compared with healthy individuals. Conclusions and Implications GPR55 is involved in the migratory behaviour of colon carcinoma cells and may serve as a pharmacological target for the prevention of metastasis. © 2015 The British Pharmacological Society PMID:26436760

Effects of phytoestrogens derived from soy bean on expression of adhesion molecules on HUVEC.

PubMed

Andrade, C M de; Sá, M F Silva de; Toloi, M R Torqueti

2012-04-01

The risks of hormone replacement therapy have led to a search for new alternatives such as phytoestrogens, plant compounds with estrogen-like biological activity. Isoflavones are the phytoestrogens most extensively studied and can be found in soybean, red clover and other plants. Due to this estrogen-like activity, phytoestrogens can have some effect on atherosclerosis. Human umbilical vein endothelial cells (HUVEC) have been extensively used to study the biology and pathobiology of human endothelial cells and most of the knowledge acquired is due to experiments with cultures of these cells. To evaluate the effects of the phytoestrogen extracts from Glycine max soy bean, genistein, formononetin, biochanin A and daidzein, as well as a mixture of these extracts (Mix), on expression of adhesion molecules, VCAM-1, ICAM-1 and E-selectin, by endothelial cell HUVEC, stimulated with lipopolysaccharide. HUVEC were cultured in medium EBM(2), pretreated with isoflavones for 24 and 48 h and then stimulated with lipopolysaccharide; in addition, isoflavones were added, after stimulation by lipopolysaccharide, to HUVEC. We evaluated the production of VCAM-1, ICAM-1 and E-selectin on cell surface, by cell-based enzyme immunoassay, and of sVCAM-1, sICAM-1 and sE-selectin in culture supernatant, by ELISA. Genistein, formononetin, biochanin A and daidzein, as well as the Mix were able to reduce VCAM-1, ICAM-1 and E-selectin on cell surface and in culture supernatant. Conclusion Isoflavones extracted from Glycine max soy bean, in vitro, presented antiatherogenic effects, reducing the expression of adhesion molecules and acting as preventive agents as well as therapeutic agents.

An Elmo–Dock complex locally controls Rho GTPases and actin remodeling during cadherin-mediated adhesion

PubMed Central

Collins, Caitlin

2014-01-01

Cell–cell contact formation is a dynamic process requiring the coordination of cadherin-based cell–cell adhesion and integrin-based cell migration. A genome-wide RNA interference screen for proteins required specifically for cadherin-dependent cell–cell adhesion identified an Elmo–Dock complex. This was unexpected as Elmo–Dock complexes act downstream of integrin signaling as Rac guanine-nucleotide exchange factors. In this paper, we show that Elmo2 recruits Dock1 to initial cell–cell contacts in Madin–Darby canine kidney cells. At cell–cell contacts, both Elmo2 and Dock1 are essential for the rapid recruitment and spreading of E-cadherin, actin reorganization, localized Rac and Rho GTPase activities, and the development of strong cell–cell adhesion. Upon completion of cell–cell adhesion, Elmo2 and Dock1 no longer localize to cell–cell contacts and are not required subsequently for the maintenance of cell–cell adhesion. These studies show that Elmo–Dock complexes are involved in both integrin- and cadherin-based adhesions, which may help to coordinate the transition of cells from migration to strong cell–cell adhesion. PMID:25452388

Inhibition of cell surface expression of endothelial adhesion molecules by ursolic acid prevents intimal hyperplasia of venous bypass grafts in rats

PubMed Central

Zeller, Iris; Wiedemann, Dominik; Schwaiger, Stefan; Stelzmüller, Marlies; Kreutmayer, Simone; Leberfing, Oliver; Stuppner, Hermann; Bernhard, David

2012-01-01

OBJECTIVES Despite rapid progress in surgical techniques, there is still a significant lack of surgery-supportive pharmacological treatments. The aim of this study was to test the hypothesis that ursolic acid (UA) may prevent intimal hyperplasia of venous bypass grafts. METHODS The hypothesis was tested by means of primary cell isolation and culture followed by real-time polymerase chain reaction, western blotting, fluorescence microscopy and fluorescence-activated cell sorting analyses, as well as an in vivo rat model for intimal hyperplasia of venous bypass grafts and immunohistochemistry and histochemistry. RESULTS The local application of UA significantly inhibited intimal hyperplasia in vivo (intimal thickness control: 25 μm, UA group: 18 μM–8 weeks after surgery). The UA treatment of grafts significantly resulted in reduced endothelial vascular cell adhesion molecule-1 (VCAM-1) expression, reduced infiltration of the grafts vessel wall by CD45-positive cells and increased smooth muscle cell (SMC) death. In in vitro condition, it could be shown that UA inhibits VCAM-1 expression downstream of NFκB and is likely to interfere with VCAM-1 protein synthesis in endothelial cells. Quantification of cell death in vascular smooth muscle cells treated with UA indicated that UA is a potent inducer of SMC apoptosis. CONCLUSIONS Our results suggest that UA-mediated inhibition of endothelial VCAM-1 expression reduces the infiltration of venous bypass grafts by CD45-positive cells and inhibits intimal hyperplasia. Apoptosis induction in SMCs may be another method in which UA reduces intimal thickening. UA may constitute a surgery-supportive pharmacon that reduces intimal hyperplasia of vein grafts. PMID:22551965

The Role of Titanium Surface Microtopography on Adhesion, Proliferation, Transformation, and Matrix Deposition of Corneal Cells.

PubMed

Zhou, Chengxin; Lei, Fengyang; Chodosh, James; Paschalis, Eleftherios I

2016-04-01

Titanium (Ti) is an excellent implantable biomaterial that can be further enhanced by surface topography optimization. Despite numerous data from orthopedics and dentistry, the effect of Ti surface topography on ocular cells is still poorly understood. In light of the recent adaptation of Ti in the Boston Keratoprosthesis artificial cornea, we attempted to perform an extended evaluation of the effect of Ti surface topography on corneal cell adhesion, proliferation, cytotoxicity, transformation, and matrix deposition. Different surface topographies were generated on medical grade Ti-6Al-4V-ELI (extra-low interstitial), with linearly increased roughness (polished to grit blasted). Biological response was evaluated in vitro using human corneal limbal epithelial (HCLE) cells, stromal fibroblasts (HCF), and endothelial cells (HCEnC). None of the Ti surface topographies caused cytotoxicity to any of the three corneal cell types. However, rough Ti surface inhibited HCLE and HCF cell adhesion and proliferation, while HCEnC proliferation was unaffected. Long-term experiments with HCF revealed that rough Ti surface with R(a) (the arithmetic average of the profile height from the mean line) ≥ 1.15 μm suppressed HCF focal adhesion kinase phosphorylation, changed fibroblast morphology, and caused less aligned and reduced deposition of collagen matrix as compared to smooth Ti (R(a) ≤ 0.08 μm). In the presence of transforming growth factor β1 (TGFβ1) stimulation, rough Ti inhibited alpha-smooth muscle actin (α-SMA) expression and collagen deposition, leading to decreased myofibroblast transformation and disorganization of the collagen fibrils as compared to smooth Ti. This study suggests that Ti surface topography regulates corneal cell behavior in a tissue-dependent manner that varies across the corneal strata. Contrary to the accepted paradigm, smooth surface topography can enhance cell adhesion and proliferation and increase matrix deposition by corneal cells.

The influence of surface carbohydrates during in vitro infection of mammalian cells by the dermatophyte Trichophyton rubrum.

PubMed

Esquenazi, Daniele; Alviano, Celuta S; de Souza, Wanderley; Rozental, Sonia

2004-04-01

In order to better understand the role played by surface glycoconjugates during host cell adhesion and endocytosis of Trichophyton rubrum, we looked for the presence of carbohydrate-binding adhesins on the microconidia surface and their role on cellular interaction with epithelial and macrophages cells. The interaction of T. rubrum with chinese hamster ovary epithelial cells and their glycosylation-deficient mutants demonstrated a higher adhesion index in Lec1 and Lec2 mutants, that express mannose and galactose, respectively. Endocytosed fungi were shown preferentially in Lec2 cells. Addition of the carbohydrates to the interaction medium, pretreatment with lectins and with sodium periodate decreased the adhesion and endocytic index for all mutants. The ability of the fungus to penetrate into mammalian cells was confirmed in experiments using macrophages treated with cytochalasin D. Flow cytometric analysis showed that this fungus recognizes mannose and galactose. The binding was inhibited by the addition of methyl alpha-D-mannopyranoside and methyl alpha-D-galactopyranoside, and showed higher fluorescence intensity at 37 than at 28 degrees C. Trypsin treatment and heating of the cells reduced the binding, suggesting a (glyco) protein nature for the microconidia adhesins. The presence of lectin-like molecules in fungus cell could be observed by scanning electron microscopy of the fungus incubated with colloidal-gold labeled neoglycoproteins. Our results suggest that T. rubrum has the ability to invade mammalian cells and expresses carbohydrate-specific adhesins on microconidia surface that recognize mannose and galactose. These adhesins may play an important role on the adhesion and invasion of the fungus during the infectious process of dermatophytosis.

Bronchial biopsy evidence for leukocyte infiltration and upregulation of leukocyte-endothelial cell adhesion molecules 6 hours after local allergen challenge of sensitized asthmatic airways.

PubMed Central

Montefort, S; Gratziou, C; Goulding, D; Polosa, R; Haskard, D O; Howarth, P H; Holgate, S T; Carroll, M P

1994-01-01

We have examined the mucosal changes occurring in bronchial biopsies from six atopic asthmatics 5-6 h after local endobronchial allergen challenge and compared them with biopsies from saline-challenged segments from the same subjects at the same time point. All the subjects developed localized bronchoconstriction in the allergen-challenged segment and had a decrease in forced expiratory volume in 1 s (FEV1) (P < 0.01) and a decrease in their methacholine provocative concentration of agonist required to reduce FEV1 from baseline by 20% (P < 0.05) 24 h postchallenge. At 6 h we observed an increase in neutrophils (P = 0.03), eosinophils (P = 0.025), mast cells (P = 0.03), and CD3+ lymphocytes (P = 0.025), but not in CD4+ or CD8+ lymphocyte counts. We also detected an increase in endothelial intercellular adhesion molecule type 1 (P < 0.05) and E-selectin (P < 0.005), but not vascular cell adhesion molecule type 1 expression with a correlative increase in submucosal and epithelial LFA+ leucocytes (P < 0.01). Thus, in sensitized asthmatics, local endobronchial allergen instillation leads to an increased inflammatory cell infiltrate of the airway mucosa that involves upregulation of specific adhesion molecules expressed on the microvasculature. Images PMID:7512980

Soluble L1CAM promotes breast cancer cell adhesion and migration in vitro, but not invasion.

PubMed

Li, Yupei; Galileo, Deni S

2010-09-15

Neural recognition molecule L1CAM, which is a key protein involved in early nervous system development, is known to be abnormally expressed and shed in several types of cancers where it participates in metastasis and progression. The distinction of L1CAM presence in cancerous vs. normal tissues has suggested it to be a new target for cancer treatment. Our current study focused on the potential role of soluble L1CAM in breast cancer cell adhesion to extracellular matrix proteins, migration, and invasion. We found L1 expression levels were correlated with breast cancer stage of progression in established data sets of clinical samples, and also were high in more metastatic breast cancer cell lines MDA-MB-231 and MDA-MB-435, but low in less migratory MDA-MB-468 cells. Proteolysis of L1 into its soluble form (sL1) was detected in cell culture medium from all three above cell lines, and can be induced by PMA activation. Over-expression of the L1 ectodomain in MDA-MB-468 cells by using a lentiviral vector greatly increased the amount of sL1 released by those cells. Concomitantly, cell adhesion to extracellular matrix and cell transmigration ability were significantly promoted, while cell invasion ability through Matrigel™ remained unaffected. On the other hand, attenuating L1 expression in MDA-MB-231 cells by using a shRNA lentiviral vector resulted in reduced cell-matrix adhesion and transmigration. Similar effects were also shown by monoclonal antibody blocking of the L1 extracellular region. Moreover, sL1 in conditioned cell culture medium induced a directional migration of MDA-MB-468 cells, which could be neutralized by antibody treatment. Our data provides new evidence for the function of L1CAM and its soluble form in promoting cancer cell adhesion to ECM and cell migration. Thus, L1CAM is validated further to be a potential early diagnostic marker in breast cancer progression and a target for breast cancer therapy.

Soluble L1CAM promotes breast cancer cell adhesion and migration in vitro, but not invasion

PubMed Central

2010-01-01

Background Neural recognition molecule L1CAM, which is a key protein involved in early nervous system development, is known to be abnormally expressed and shed in several types of cancers where it participates in metastasis and progression. The distinction of L1CAM presence in cancerous vs. normal tissues has suggested it to be a new target for cancer treatment. Our current study focused on the potential role of soluble L1CAM in breast cancer cell adhesion to extracellular matrix proteins, migration, and invasion. Results We found L1 expression levels were correlated with breast cancer stage of progression in established data sets of clinical samples, and also were high in more metastatic breast cancer cell lines MDA-MB-231 and MDA-MB-435, but low in less migratory MDA-MB-468 cells. Proteolysis of L1 into its soluble form (sL1) was detected in cell culture medium from all three above cell lines, and can be induced by PMA activation. Over-expression of the L1 ectodomain in MDA-MB-468 cells by using a lentiviral vector greatly increased the amount of sL1 released by those cells. Concomitantly, cell adhesion to extracellular matrix and cell transmigration ability were significantly promoted, while cell invasion ability through Matrigel™ remained unaffected. On the other hand, attenuating L1 expression in MDA-MB-231 cells by using a shRNA lentiviral vector resulted in reduced cell-matrix adhesion and transmigration. Similar effects were also shown by monoclonal antibody blocking of the L1 extracellular region. Moreover, sL1 in conditioned cell culture medium induced a directional migration of MDA-MB-468 cells, which could be neutralized by antibody treatment. Conclusions Our data provides new evidence for the function of L1CAM and its soluble form in promoting cancer cell adhesion to ECM and cell migration. Thus, L1CAM is validated further to be a potential early diagnostic marker in breast cancer progression and a target for breast cancer therapy. PMID:20840789

Nanowell-Trapped Charged Ligand-Bearing Nanoparticle Surfaces – A Novel Method of Enhancing Flow-Resistant Cell Adhesion

PubMed Central

Tran, Phat L.; Gamboa, Jessica R.; McCracken, Katherine E.; Riley, Mark R.

2014-01-01

Assuring cell adhesion to an underlying biomaterial surface is vital in implant device design and tissue engineering, particularly under circumstances where cells are subjected to potential detachment from overriding fluid flow. Cell-substrate adhesion is a highly regulated process involving the interplay of mechanical properties, surface topographic features, electrostatic charge, and biochemical mechanisms. At the nanoscale level the physical properties of the underlying substrate are of particular importance in cell adhesion. Conventionally, natural, pro-adhesive, and often thrombogenic, protein biomaterials are frequently utilized to facilitate adhesion. In the present study nanofabrication techniques are utilized to enhance the biological functionality of a synthetic polymer surface, polymethymethacrylate, with respect to cell adhesion. Specifically we examine the effect on cell adhesion of combining: 1. optimized surface texturing, 2. electrostatic charge and 3. cell adhesive ligands, uniquely assembled on the substrata surface, as an ensemble of nanoparticles trapped in nanowells. Our results reveal that the ensemble strategy leads to enhanced, more than simply additive, endothelial cell adhesion under both static and flow conditions. This strategy may be of particular utility for enhancing flow-resistant endothelialization of blood-contacting surfaces of cardiovascular devices subjected to flow-mediated shear. PMID:23225491

Protecting the BBB Endothelium against Cigarette Smoke-Induced Oxidative Stress Using Popular Antioxidants: Are they really beneficial?

PubMed Central

Kaisar, Mohammad Abul; Prasad, Shikha; Cucullo, Luca

2015-01-01

Blood Brain Barrier (BBB) exposed to realistic concentrations (comparable to a chronic heavy smoker) of Cigarette Smoke Extract (CSE) triggers a strong endothelial inflammatory which can lead to the onset of neurological disorders. The involvement of Reactive Oxygen Species (ROS) in this inflammatory cascade is evident from the up-regulation of nuclear factor erythroid 2 related factor 2 (Nrf-2), a transcription factor involved in anti-oxidant response signaling in CSE exposed endothelial cells. We have shown that pre-treatment with α-tocopherol and/or ascorbic acid is highly protective for the BBB, thus suggesting that, prophylactic administration of antioxidants can reduce CSE and/or inflammatory-dependent BBB damage. We have assessed and ranked the protective effects of 5 popular OTC antioxidants (Coenzyme Q10, Melatonin, Glutathione, Lipoic acid and Resveratrol) against CSE-induced BBB endothelial damage using hCMEC/D3 cells. The analysis of pro-inflammatory cytokines release by ELISA revealed that, resveratrol, lipoic acid melatonin and Co-Q10 inhibited the BBB endothelial release of pro-inflammatory cytokines IL-6 & IL-8, reduced (not Co-Q10) CSE-induced up-regulation of Platelet Endothelial Cell Adhesion Molecule -1 (PECAM-1), Vascular Endothelial Cell Adhesion Molecule-1 (VCAM-1) & E-selectin and inhibited monocytes-endothelial cell adhesion. The anti-inflammatory effects correlated with the anti-oxidative protection endowed by these compounds as evidenced by upregulation of NADPH: Quinone Oxidoreductase 1 (NQO1) and reduced cellular oxidative stress. CSE-induced release of Vascular Endothelial Growth Factor (VEGF) was inhibited by all tested compounds although the effect was not strictly dose-dependent. Further in vivo studies are required to validate our results and expand our current study to include combinatorial treatments. PMID:26410779

The effects of titanium nitride-coating on the topographic and biological features of TPS implant surfaces.

PubMed

Annunziata, Marco; Oliva, Adriana; Basile, Maria Assunta; Giordano, Michele; Mazzola, Nello; Rizzo, Antonietta; Lanza, Alessandro; Guida, Luigi

2011-11-01

Titanium nitride (TiN) coating has been proposed as an adjunctive surface treatment aimed to increase the physico-mechanical and aesthetic properties of dental implants. In this study we investigated the surface characteristics of TiN-coated titanium plasma sprayed (TiN-TPS) and uncoated titanium plasma sprayed (TPS) surfaces and their biological features towards both primary human bone marrow mesenchymal stem cells (BM-MSC) and bacterial cultures. 15 mm×1 mm TPS and TiN-TPS disks (P.H.I. s.r.l., San Vittore Olona, Milano, Italy) were topographically analysed by confocal optical profilometry. Primary human BM-MSC were obtained from healthy donors, isolated and expanded. Cells were seeded on the titanium disks and cell adhesion, proliferation, protein synthesis and osteoblastic differentiation in terms of alkaline phosphatase activity, osteocalcin synthesis and extracellular mineralization, were evaluated. Furthermore, adhesion and proliferation of Streptococcus pyogenes and Streptococcus sanguinis on both surfaces were also analysed. TiN-TPS disks showed a decreased roughness (about 50%, p < 0.05) and a decreased bacterial adhesion and proliferation compared to TPS ones. No difference (p > 0.05) in terms of BM-MSC adhesion, proliferation and osteoblastic differentiation between TPS and TiN-TPS surfaces was found. TiN coating showed to modify the topographical characteristics of TPS titanium surfaces and to significantly reduce bacterial adhesion and proliferation, although maintaining their biological affinity towards bone cell precursors. Copyright © 2011 Elsevier Ltd. All rights reserved.

Flagellar Cap Protein FliD Mediates Adherence of Atypical Enteropathogenic Escherichia coli to Enterocyte Microvilli

PubMed Central

Sampaio, Suely C. F.; Luiz, Wilson B.; Vieira, Mônica A. M.; Ferreira, Rita C. C.; Garcia, Bruna G.; Sinigaglia-Coimbra, Rita; Sampaio, Jorge L. M.; Ferreira, Luís C. S.

2016-01-01

The expression of flagella correlates with different aspects of bacterial pathogenicity, ranging from adherence to host cells to activation of inflammatory responses by the innate immune system. In the present study, we investigated the role of flagella in the adherence of an atypical enteropathogenic Escherichia coli (aEPEC) strain (serotype O51:H40) to human enterocytes. Accordingly, isogenic mutants deficient in flagellin (FliC), the flagellar structural subunit; the flagellar cap protein (FliD); or the MotAB proteins, involved in the control of flagellar motion, were generated and tested for binding to differentiated Caco-2 cells. Binding of the aEPEC strain to enterocytes was significantly impaired in strains with the fliC and fliD genes deleted, both of which could not form flagella on the bacterial surface. A nonmotile but flagellated MotAB mutant also showed impaired adhesion to Caco-2 cells. In accordance with these observations, adhesion of aEPEC strain 1711-4 to Caco-2 cells was drastically reduced after the treatment of Caco-2 cells with purified FliD. In addition, incubation of aEPEC bacteria with specific anti-FliD serum impaired binding to Caco-2 cells. Finally, incubation of Caco-2 cells with purified FliD, followed by immunolabeling, showed that the protein was specifically bound to the microvillus tips of differentiated Caco-2 cells. The aEPEC FliD or anti-FliD serum also reduced the adherence of prototype typical enteropathogenic, enterohemorrhagic, and enterotoxigenic E. coli strains to Caco-2 cells. In conclusion, our findings further strengthened the role of flagella in the adherence of aEPEC to human enterocytes and disclosed the relevant structural and functional involvement of FliD in the adhesion process. PMID:26831466

Protective effects of hydrogen-rich medium on lipopolysaccharide-induced monocytic adhesion and vascular endothelial permeability through regulation of vascular endothelial cadherin.

PubMed

Yu, Y; Wang, W N; Han, H Z; Xie, K L; Wang, G L; Yu, Y H

2015-06-11

We observed the effect of hydrogen-rich medium on lipopolysaccharide (LPS)-induced human umbilical vein endothelial cells (HUVECs), hyaline leukocyte conglutination, and permeability of the endothelium. Endotheliocytes were inoculated on 6-well plates and randomly divided into 4 groups: control, H2, LPS, LPS+H2, H2, and LPS+H2 in saturated hydrogen-rich medium. We applied Wright's stain-ing to observe conglutination of hyaline leukocytes and HUVECs, flow cytometry to determine the content of vascular cell adhesion protein 1 (VCAM-1) and intercellular adhesion molecule 1 (ICAM-1), enzyme-linked immunosorbent assay to measure the E-selectin concentration in the cell liquor, the transendothelial electrical resistance (TEER) to test the permeability of endothelial cells, and Western blot and immunofluorescence to test the expression and distribution of vascular endothelial (VE)-cadherin. Compared with control cells, there was an increase in endothelium-hyaline leukocyte conglutination, a reduction in VCAM-1, ICAM-1, and E-selectin, and the TEER value increased obviously. Compared with LPS, there was an obvious reduction in the conglutination of LPS+H2 cells, a reduction in VCAM-1, ICAM-1, and E-selectin levels, and a reduction in the TEER-resistance value, while the expression of VE-cadherin increased. Fluorescence results showed that, compared with control cells, the VE-cadherin in LPS cells was in-complete at the cell joints. Compared with LPS cells, the VE-cadherin in LPS+H2 cells was even and complete at the cell joints. Liquid rich in hydrogen could reduce LPS-induced production of adhesion molecules and endothelium-hyaline leukocyte conglutination, and influence the expression and distribution of VE-cadherin to regulate the permeability of the endothelium.

Blocking hepatic metastases of colon cancer cells using an shRNA against Rac1 delivered by activatable cell-penetrating peptide.

PubMed

Bao, Ying; Guo, Huihui; Lu, Yongliang; Feng, Wenming; Sun, Xinrong; Tang, Chengwu; Wang, Xiang; Shen, Mo

2016-11-22

Hepatic metastasis is one of the critical progressions of colon cancer. Blocking this process is key to prolonging survival time in cancer patients. Studies on activatable cell-penetrating peptides (dtACPPs) have demonstrated their potential as gene carriers. It showed high tumor cell-targeting specificity and transfection efficiency and low cytotoxicity in the in vitro settings of drug delivery. However, using this system to silence target genes to inhibit metastasis in colorectal cancer cells has not been widely reported and requires further investigation. In this study, we observed that expression of Rac1, a key molecule for cytoskeletal reorganization, was higher in hepatic metastatic tumor tissue compared with prime colon cancer tissue and that patients with high Rac1-expressing colon cancer showed shorter survival time. Base on these findings, we created dtACPP-PEG-DGL (dtACPPD)/shRac1 nanoparticles and demonstrated that they downregulated Rac1 expression in colon cancer cells. Moreover, we observed inhibitory effects on migration, invasion and adhesion in HCT116 colorectal cancer cells in vitro, and our results showed that Rac1 regulated colon cancer cell matrix adhesion through the regulation of cytofilament dynamics. Moreover, mechanically, repression of Rac1 inhibiting cells migration and invasion by enhancing cell to cell adhesion and reducing cell to extracellular matrix adhesion. Furthermore, when atCDPPD/shRac1 nanoparticles were administered intravenously to a HCT116 xenograft model, significant tumor metastasis to the liver was inhibited. Our results suggest that atCDPP/shRac1 nanoparticles may enable the blockade of hepatic metastasis in colon cancer.

Electrostatic-Force-Assisted Dispensing Printing to Construct High-Aspect-Ratio of 0.79 Electrodes on a Textured Surface with Improved Adhesion and Contact Resistivity

PubMed Central

Shin, Dong-Youn; Yoo, Sung-Soo; Song, Hee-eun; Tak, Hyowon; Byun, Doyoung

2015-01-01

As a novel route to construct fine and abnormally high-aspect-ratio electrodes with excellent adhesion and reduced contact resistivity on a textured surface, an electrostatic-force-assisted dispensing printing technique is reported and compared with conventional dispensing and electrohydrodynamic jet printing techniques. The electrostatic force applied between a silver paste and the textured surface of a crystalline silicon solar cell wafer significantly improves the physical adhesion of the electrodes, whereas those fabricated using a conventional dispensing printing technique peel off with a silver paste containing 2 wt% of a fluorosurfactant. Moreover, the contact resistivity and dimensionless deviation of total resistance are significantly reduced from 2.19 ± 1.53 mΩ·cm2 to 0.98 ± 0.92 mΩ·cm2 and from 0.10 to 0.03, respectively. By utilizing electrodes with an abnormally high-aspect-ratio of 0.79 (the measured thickness and width are 30.4 μm and 38.3 μm, respectively), the cell efficiency is 17.2% on a polycrystalline silicon solar cell with an emitter sheet resistance of 60 Ω/sq. This cell efficiency is considerably higher than previously reported values obtained using a conventional electrohydrodynamic jet printing technique, by +0.48–3.5%p. PMID:26576857

Inhibitory Effect of a French Maritime Pine Bark Extract-Based Nutritional Supplement on TNF-α-Induced Inflammation and Oxidative Stress in Human Coronary Artery Endothelial Cells

PubMed Central

McGrath, Kristine C. Y.; Li, Xiao-Hong; McRobb, Lucinda S.; Heather, Alison K.

2015-01-01

Oxidative stress and inflammation, leading to endothelial dysfunction, contribute to the pathogenesis of atherosclerosis. The popularity of natural product supplements has increased in recent years, especially those with purported anti-inflammatory and/or antioxidant effects. The efficacy and mechanism of many of these products are not yet well understood. In this study, we tested the antioxidant and anti-inflammatory effects of a supplement, HIPER Health Supplement (HIPER), on cytokine-induced inflammation and oxidative stress in human coronary artery endothelial cells (HCAECs). HIPER is a mixture of French maritime pine bark extract (PBE), honey, aloe vera, and papaya extract. Treatment for 24 hours with HIPER reduced TNF-α-induced reactive oxygen species (ROS) generation that was associated with decreased NADPH oxidase 4 and increased superoxide dismutase-1 expression. HIPER inhibited TNF-α induced monocyte adhesion to HCAECs that was in keeping with decreased expression of vascular cell adhesion molecule-1 and intercellular cell adhesion molecule-1 and decreased nuclear factor-kappa B (NF-κB) activation. Further investigation of mechanism showed HIPER reduced TNF-α induced IκBα and p38 and MEK1/2 MAP kinases phosphorylation. Our findings show that HIPER has potent inhibitory effects on HCAECs inflammatory and oxidative stress responses that may protect against endothelial dysfunction that underlies early atherosclerotic lesion formation. PMID:26664450

Protein SUMOylation is Involved in Cell-cycle Progression and Cell Morphology in Giardia lamblia.

PubMed

Di Genova, Bruno M; da Silva, Richard C; da Cunha, Júlia P C; Gargantini, Pablo R; Mortara, Renato A; Tonelli, Renata R

2017-07-01

The unicellular protozoa Giardia lamblia is a food- and waterborne parasite that causes giardiasis. This illness is manifested as acute and self-limited diarrhea and can evolve to long-term complications. Successful establishment of infection by Giardia trophozoites requires adhesion to host cells and colonization of the small intestine, where parasites multiply by mitotic division. The tight binding of trophozoites to host cells occurs by means of the ventral adhesive disc, a spiral array of microtubules and associated proteins such as giardins. In this work we show that knock down of the Small Ubiquitin-like MOdifier (SUMO) results in less adhesive trophzoites, decreased cell proliferation and deep morphological alterations, including at the ventral disc. Consistent with the reduced proliferation, SUMO knocked-down trophozoites were arrested in G1 and in S phases of the cell cycle. Mass spectrometry analysis of anti-SUMO immunoprecipitates was performed to identify SUMO substrates possibly involved in these events. Among the identified SUMOylation targets, α-tubulin was further validated by Western blot and confirmed to be a SUMO target in Giardia trophozoites. © 2016 The Author(s) Journal of Eukaryotic Microbiology © 2016 International Society of Protistologists.

“Do-it-yourself in vitro vasculature that recapitulates in vivo geometries for investigating endothelial-blood cell interactions”

PubMed Central

Mannino, Robert G.; Myers, David R.; Ahn, Byungwook; Wang, Yichen; Margo Rollins; Gole, Hope; Lin, Angela S.; Guldberg, Robert E.; Giddens, Don P.; Timmins, Lucas H.; Lam, Wilbur A.

2015-01-01

Investigating biophysical cellular interactions in the circulation currently requires choosing between in vivo models, which are difficult to interpret due in part to the hemodynamic and geometric complexities of the vasculature; or in vitro systems, which suffer from non-physiologic assumptions and/or require specialized microfabrication facilities and expertise. To bridge that gap, we developed an in vitro “do-it-yourself” perfusable vasculature model that recapitulates in vivo geometries, such as aneurysms, stenoses, and bifurcations, and supports endothelial cell culture. These inexpensive, disposable devices can be created rapidly (<2 hours) with high precision and repeatability, using standard off-the-shelf laboratory supplies. Using these “endothelialized” systems, we demonstrate that spatial variation in vascular cell adhesion molecule (VCAM-1) expression correlates with the wall shear stress patterns of vascular geometries. We further observe that the presence of endothelial cells in stenoses reduces platelet adhesion but increases sickle cell disease (SCD) red blood cell (RBC) adhesion in bifurcations. Overall, our method enables researchers from all disciplines to study cellular interactions in physiologically relevant, yet simple-to-make, in vitro vasculature models. PMID:26202603

PO-12 - The key role of talin-1 in cancer cell extravasation dissected through human vascularized 3D microfluidic model.

PubMed

Gilardi, M; Bersini, S; Calleja, A Boussomier; Kamm, R D; Vanoni, M; Moretti, M

2016-04-01

Metastases are responsible for more than 90% of cancer related mortality. The hematogenous metastatic invasion is a complex process in which the endothelium plays a key role. Extravasation is a dynamic process involving remodeling and change in cell shape and in cytoskeleton whereby a series of strongly dependent interactions between CTCs and endothelium occurs [1]. Talins are proteins regulating focal adhesions and cytoskeleton remodeling. Talin-1 seems to be involved in the aggressiveness, motility, survival and invadopodia formation of cancer cells throughout the entire metastatic cascade [2], being up-regulated in breast cancer cells and mutated in sarcomas. Understand the implication of talin-1 in extravasation could facilitate the design of new therapies and finally fight cancer. We hypothesized that Talin-1 could be specifically involved in extravasation driving each of its steps. We developed a human 3D microfluidic model that enables the study of human cancer cell extravasation within a perfusable human microvascularized organ specific environment[3]. For the study of extravasation we applied microfluidic approach through the development of a microfluidic device in which endothelial cells and fibroblasts generated a 3D human functional vascular networks. Microvessel characterization was performed with immunofluorescence and permeability assays. We knocked-down talin-1 in triple negative breast cancer cell line MDA-MB231 and metastatic fibro-sarcoma cell line HT1080 with SiRNA and verified by Western-blot. Cancer cells were then perfused in the vessels and extravasation monitored through confocal imaging. We developed a human vascularized 3D microfluidic device with human perfusable capillary-like structures embedded in fibrin matrix, characterized by mature endothelium markers and physiological permeability (1.5±0.76)×10(-6) cm/s. We focused on the role of Talin-1 in adhesion to endothelium, trans-endothelial migration (TEM) and early invasion. Adhesion to the endothelium, TEM and migration within the ECM were monitored through confocal analyses. We demonstrated that Talin-1 KD significantly reduced the adhesion efficiency and TEM in both cell lines. Early invasion was also strongly and statistically reduced by the SiRNA treatment in both cell lines. We proved Talin-1 function in driving the extravasation mechanism in a human 3D vascularized environment. We demonstrated that Talin-1 is involved in each part of extravasation significantly affecting adhesion, TEM and the invasion stages. Targeting this protein could thus be an effective strategy to block metastasis. © 2016 Elsevier Ltd. All rights reserved.

Single- and double-walled carbon nanotubes enhance atherosclerogenesis by promoting monocyte adhesion to endothelial cells and endothelial progenitor cell dysfunction.

PubMed

Suzuki, Yuka; Tada-Oikawa, Saeko; Hayashi, Yasuhiko; Izuoka, Kiyora; Kataoka, Misa; Ichikawa, Shunsuke; Wu, Wenting; Zong, Cai; Ichihara, Gaku; Ichihara, Sahoko

2016-10-13

The use of carbon nanotubes has increased lately. However, the cardiovascular effect of exposure to carbon nanotubes remains elusive. The present study investigated the effects of pulmonary exposure to single-walled carbon nanotubes (SWCNTs) and double-walled carbon nanotubes (DWCNTs) on atherosclerogenesis using normal human aortic endothelial cells (HAECs) and apolipoprotein E-deficient (ApoE -/- ) mice, a model of human atherosclerosis. HAECs were cultured and exposed to SWCNTs or DWCNTs for 16 h. ApoE -/- mice were exposed to SWCNTs or DWCNTs (10 or 40 μg/mouse) once every other week for 10 weeks by pharyngeal aspiration. Exposure to CNTs increased the expression level of adhesion molecule (ICAM-1) and enhanced THP-1 monocyte adhesion to HAECs. ApoE -/- mice exposed to CNTs showed increased plaque area in the aorta by oil red O staining and up-regulation of ICAM-1 expression in the aorta, compared with vehicle-treated ApoE -/- mice. Endothelial progenitor cells (EPCs) are mobilized from the bone marrow into the circulation and subsequently migrate to the site of endothelial damage and repair. Exposure of ApoE -/- mice to high-dose SWCNTs or DWCNTs reduced the colony-forming units of EPCs in the bone marrow and diminished their migration function. The results suggested that SWCNTs and DWCNTs enhanced atherosclerogenesis by promoting monocyte adhesion to endothelial cells and inducing EPC dysfunction.

Propionyl-L-Carnitine is Efficacious in Ulcerative Colitis Through its Action on the Immune Function and Microvasculature.

PubMed

Scioli, Maria Giovanna; Stasi, Maria Antonietta; Passeri, Daniela; Doldo, Elena; Costanza, Gaetana; Camerini, Roberto; Fociani, Paolo; Arcuri, Gaetano; Lombardo, Katia; Pace, Silvia; Borsini, Franco; Orlandi, Augusto

2014-03-20

Microvascular endothelial dysfunction characterizes ulcerative colitis (UC), the most widespread form of inflammatory bowel disease. Intestinal mucosal microvessels in UC display aberrant expression of cell adhesion molecules (CAMs) and increased inflammatory cell recruitment. Propionyl-L-carnitine (PLC), an ester of L-carnitine required for the mitochondrial transport of fatty acids, ameliorates propionyl-CoA bioavailability and reduces oxidative stress in ischemic tissues. The present study aimed to document the efficacy of anti-oxidative stress properties of PLC in counteracting intestinal microvascular endothelial dysfunction and inflammation. To evaluate the efficacy in vivo, we analyzed the effects in intestinal biopsies of patients with mild-to-moderate UC receiving oral PLC co-treatment and in rat TNBS-induced colitis; in addition, we investigated antioxidant PLC action in TNF-α-stimulated human intestinal microvascular endothelial cells (HIMECs) in vitro. Four-week PLC co-treatment reduced intestinal mucosal polymorph infiltration and CD4(+) lymphocytes, ICAM-1(+) and iNOS(+) microvessels compared with placebo-treated patients with UC. Oral and intrarectal administration of PLC but not L-carnitine or propionate reduced intestinal damage and microvascular dysfunction in rat TNBS-induced acute and reactivated colitis. In cultured TNF-α-stimulated HIMECs, PLC restored β-oxidation and counteracted NADPH oxidase 4-generated oxidative stress-induced CAM expression and leukocyte adhesion. Inhibition of β-oxidation by L-aminocarnitine increased reactive oxygen species production and PLC beneficial effects on endothelial dysfunction and leukocyte adhesion. Finally, PLC reduced iNOS activity and nitric oxide accumulation in rat TNBS-induced colitis and in HIMEC cultures. Our results show that the beneficial antioxidant effect of PLC targeting intestinal microvasculature restores endothelial β-oxidation and function, and reduces mucosal inflammation in UC patients.

Propionyl-L-Carnitine is Efficacious in Ulcerative Colitis Through its Action on the Immune Function and Microvasculature

PubMed Central

Scioli, Maria Giovanna; Stasi, Maria Antonietta; Passeri, Daniela; Doldo, Elena; Costanza, Gaetana; Camerini, Roberto; Fociani, Paolo; Arcuri, Gaetano; Lombardo, Katia; Pace, Silvia; Borsini, Franco; Orlandi, Augusto

2014-01-01

Objectives: Microvascular endothelial dysfunction characterizes ulcerative colitis (UC), the most widespread form of inflammatory bowel disease. Intestinal mucosal microvessels in UC display aberrant expression of cell adhesion molecules (CAMs) and increased inflammatory cell recruitment. Propionyl-L-carnitine (PLC), an ester of L-carnitine required for the mitochondrial transport of fatty acids, ameliorates propionyl-CoA bioavailability and reduces oxidative stress in ischemic tissues. The present study aimed to document the efficacy of anti-oxidative stress properties of PLC in counteracting intestinal microvascular endothelial dysfunction and inflammation. Methods: To evaluate the efficacy in vivo, we analyzed the effects in intestinal biopsies of patients with mild-to-moderate UC receiving oral PLC co-treatment and in rat TNBS-induced colitis; in addition, we investigated antioxidant PLC action in TNF-α-stimulated human intestinal microvascular endothelial cells (HIMECs) in vitro. Results: Four-week PLC co-treatment reduced intestinal mucosal polymorph infiltration and CD4+ lymphocytes, ICAM-1+ and iNOS+ microvessels compared with placebo-treated patients with UC. Oral and intrarectal administration of PLC but not L-carnitine or propionate reduced intestinal damage and microvascular dysfunction in rat TNBS-induced acute and reactivated colitis. In cultured TNF-α-stimulated HIMECs, PLC restored β-oxidation and counteracted NADPH oxidase 4-generated oxidative stress-induced CAM expression and leukocyte adhesion. Inhibition of β-oxidation by L-aminocarnitine increased reactive oxygen species production and PLC beneficial effects on endothelial dysfunction and leukocyte adhesion. Finally, PLC reduced iNOS activity and nitric oxide accumulation in rat TNBS-induced colitis and in HIMEC cultures. Conclusions: Our results show that the beneficial antioxidant effect of PLC targeting intestinal microvasculature restores endothelial β-oxidation and function, and reduces mucosal inflammation in UC patients. PMID:24646507

Reduced Expression of Adipose Triglyceride Lipase Enhances Tumor Necrosis Factor α-induced Intercellular Adhesion Molecule-1 Expression in Human Aortic Endothelial Cells via Protein Kinase C-dependent Activation of Nuclear Factor-κB*

PubMed Central

Inoue, Tomoaki; Kobayashi, Kunihisa; Inoguchi, Toyoshi; Sonoda, Noriyuki; Fujii, Masakazu; Maeda, Yasutaka; Fujimura, Yoshinori; Miura, Daisuke; Hirano, Ken-ichi; Takayanagi, Ryoichi

2011-01-01

We examined the effects of adipose triglyceride lipase (ATGL) on the initiation of atherosclerosis. ATGL was recently identified as a rate-limiting triglyceride (TG) lipase. Mutations in the human ATGL gene are associated with neutral lipid storage disease with myopathy, a rare genetic disease characterized by excessive accumulation of TG in multiple tissues. The cardiac phenotype, known as triglyceride deposit cardiomyovasculopathy, shows massive TG accumulation in both coronary atherosclerotic lesions and the myocardium. Recent reports show that myocardial triglyceride content is significantly higher in patients with prediabetes or diabetes and that ATGL expression is decreased in the obese insulin-resistant state. Therefore, we investigated the effect of decreased ATGL activity on the development of atherosclerosis using human aortic endothelial cells. We found that ATGL knockdown enhanced monocyte adhesion via increased expression of TNFα-induced intercellular adhesion molecule-1 (ICAM-1). Next, we determined the pathways (MAPK, PKC, or NFκB) involved in ICAM-1 up-regulation induced by ATGL knockdown. Both phosphorylation of PKC and degradation of IκBα were increased in ATGL knockdown human aortic endothelial cells. In addition, intracellular diacylglycerol levels and free fatty acid uptake via CD36 were significantly increased in these cells. Inhibition of the PKC pathway using calphostin C and GF109203X suppressed TNFα-induced ICAM-1 expression. In conclusion, we showed that ATGL knockdown increased monocyte adhesion to the endothelium through enhanced TNFα-induced ICAM-1 expression via activation of NFκB and PKC. These results suggest that reduced ATGL expression may influence the atherogenic process in neutral lipid storage diseases and in the insulin-resistant state. PMID:21828047

Human Endometrial CD98 Is Essential for Blastocyst Adhesion

PubMed Central

Domínguez, Francisco; Simón, Carlos; Quiñonero, Alicia; Ramírez, Miguel Ángel; González-Muñoz, Elena; Burghardt, Hans; Cervero, Ana; Martínez, Sebastián; Pellicer, Antonio; Palacín, Manuel; Sánchez-Madrid, Francisco; Yáñez-Mó, María

2010-01-01

Background Understanding the molecular basis of embryonic implantation is of great clinical and biological relevance. Little is currently known about the adhesion receptors that determine endometrial receptivity for embryonic implantation in humans. Methods and Principal Findings Using two human endometrial cell lines characterized by low and high receptivity, we identified the membrane receptor CD98 as a novel molecule selectively and significantly associated with the receptive phenotype. In human endometrial samples, CD98 was the only molecule studied whose expression was restricted to the implantation window in human endometrial tissue. CD98 expression was restricted to the apical surface and included in tetraspanin-enriched microdomains of primary endometrial epithelial cells, as demonstrated by the biochemical association between CD98 and tetraspanin CD9. CD98 expression was induced in vitro by treatment of primary endometrial epithelial cells with human chorionic gonadotropin, 17-β-estradiol, LIF or EGF. Endometrial overexpression of CD98 or tetraspanin CD9 greatly enhanced mouse blastocyst adhesion, while their siRNA-mediated depletion reduced the blastocyst adhesion rate. Conclusions These results indicate that CD98, a component of tetraspanin-enriched microdomains, appears to be an important determinant of human endometrial receptivity during the implantation window. PMID:20976164

An Inducible Endothelial Cell Surface Glycoprotein Mediates Melanoma Adhesion

NASA Astrophysics Data System (ADS)

Rice, G. Edgar; Bevilacqua, Michael P.

1989-12-01

Hematogenous metastasis requires the arrest and extravasation of blood-borne tumor cells, possibly involving direct adhesive interactions with vascular endothelium. Cytokine activation of cultured human endothelium increases adhesion of melanoma and carcinoma cell lines. An inducible 110-kD endothelial cell surface glycoprotein, designated INCAM-110, appears to mediate adhesion of melanoma cells. In addition, an inducible endothelial receptor for neutrophils, ELAM-1, supports the adhesion of a human colon carcinoma cell line. Thus, activation of vascular endothelium in vivo that results in increased expression of INCAM-110 and ELAM-1 may promote tumor cell adhesion and affect the incidence and distribution of metastases.

9-cis-Retinoic Acid Promotes Cell Adhesion Through Integrin Dependent and Independent Mechanisms Across Immune Lineages

PubMed Central

Whelan, Jarrett T.; Chen, Jianming; Miller, Jabin; Morrow, Rebekah L.; Lingo, Joshuah D.; Merrell, Kaitlin; Shaikh, Saame Raza; Bridges, Lance C.

2012-01-01

Retinoids are essential in the proper establishment and maintenance of immunity. Although retinoids are implicated in immune related processes, their role in immune cell adhesion has not been well established. In this study, the effect of 9-cis-retinoic acid (9-cis-RA) on human hematopoietic cell adhesion was investigated. 9-cis-RA treatment specifically induced cell adhesion of the human immune cell lines HuT-78, NB4, RPMI 8866, and U937. Due to the prominent role of integrin receptors in mediating immune cell adhesion, we sought to evaluate if cell adhesion was integrin-dependent. By employing a variety of integrin antagonist including function-blocking antibodies and EDTA, we establish that 9-cis-RA prompts immune cell adhesion through established integrin receptors in addition to a novel integrin-independent process. The novel integrin-independent adhesion required the presence of retinoid and was attenuated by treatment with synthetic corticosteroids. Finally, we demonstrate that 9-cis-RA treatment of primary murine B-cells induces ex vivo adhesion that persists in the absence of integrin function. Our study is the first to demonstrate that 9-cis-retinoic acid influences immune cell adhesion through at least two functionally distinct mechanisms. PMID:22925918

Role of cellular adhesions in tissue dynamics spectroscopy

NASA Astrophysics Data System (ADS)

Merrill, Daniel A.; An, Ran; Turek, John; Nolte, David

2014-02-01

Cellular adhesions play a critical role in cell behavior, and modified expression of cellular adhesion compounds has been linked to various cancers. We tested the role of cellular adhesions in drug response by studying three cellular culture models: three-dimensional tumor spheroids with well-developed cellular adhesions and extracellular matrix (ECM), dense three-dimensional cell pellets with moderate numbers of adhesions, and dilute three-dimensional cell suspensions in agarose having few adhesions. Our technique for measuring the drug response for the spheroids and cell pellets was biodynamic imaging (BDI), and for the suspensions was quasi-elastic light scattering (QELS). We tested several cytoskeletal chemotherapeutic drugs (nocodazole, cytochalasin-D, paclitaxel, and colchicine) on three cancer cell lines chosen from human colorectal adenocarcinoma (HT-29), human pancreatic carcinoma (MIA PaCa-2), and rat osteosarcoma (UMR-106) to exhibit differences in adhesion strength. Comparing tumor spheroid behavior to that of cell suspensions showed shifts in the spectral motion of the cancer tissues that match predictions based on different degrees of cell-cell contacts. The HT-29 cell line, which has the strongest adhesions in the spheroid model, exhibits anomalous behavior in some cases. These results highlight the importance of using three-dimensional tissue models in drug screening with cellular adhesions being a contributory factor in phenotypic differences between the drug responses of tissue and cells.

Platelet adhesion via glycoprotein IIb integrin is critical for atheroprogression and focal cerebral ischemia: an in vivo study in mice lacking glycoprotein IIb.

PubMed

Massberg, Steffen; Schürzinger, Katrin; Lorenz, Michael; Konrad, Ildiko; Schulz, Christian; Plesnila, Nikolaus; Kennerknecht, Elisabeth; Rudelius, Martina; Sauer, Susanne; Braun, Siegmund; Kremmer, Elisabeth; Emambokus, Nikla R; Frampton, Jon; Gawaz, Meinrad

2005-08-23

The platelet glycoprotein (GP) IIb/IIIa integrin binds to fibrinogen and thereby mediates platelet aggregation. Here, we addressed the role of GP IIb for platelet adhesion and determined the relevance of platelet GP IIb for the processes of atherosclerosis and cerebral ischemia-reperfusion (I/R) injury. GP IIb(-/-) mice were generated and bred with ApoE(-/-) animals to create GP IIb(-/-)ApoE(-/-) mice. Platelet adhesion to the mechanically injured or atherosclerotic vessel wall was monitored by in vivo video fluorescence microscopy. In the presence of GP IIb, vascular injury and early atherosclerosis induced platelet adhesion in the carotid artery (CA). In contrast, platelet adhesion was significantly reduced in the absence of GP IIb integrin (P<0.05). To address the contribution of platelet GP IIb to atheroprogression, we determined atherosclerotic lesion formation in the CA and aortic arch (AA) of GP IIb(+/+)ApoE(-/-) or GP IIb(-/-)ApoE(-/-) mice. Interestingly, the absence of GP IIb attenuated lesion formation in CA and AA, indicating that platelets, via GP IIb, contribute substantially to atherosclerosis. Next, we assessed the implication of GP IIb for cerebral I/R injury. We observed that after occlusion of the middle cerebral artery, the cerebral infarct size was drastically reduced in mice lacking GP IIb compared with wild-types. These findings show for the first time in vivo that GP IIb not only mediates platelet aggregation but also triggers platelet adhesion to exposed extracellular matrices and dysfunctional endothelial cells. In a process strictly involving GP IIb, platelets, which are among the first blood cells to arrive at the scene of endothelial dysfunction, contribute essentially to atherosclerosis and cerebral I/R injury.

Cortactin deficiency is associated with reduced neutrophil recruitment but increased vascular permeability in vivo.

PubMed

Schnoor, Michael; Lai, Frank P L; Zarbock, Alexander; Kläver, Ruth; Polaschegg, Christian; Schulte, Dörte; Weich, Herbert A; Oelkers, J Margit; Rottner, Klemens; Vestweber, Dietmar

2011-08-01

Neutrophil extravasation and the regulation of vascular permeability require dynamic actin rearrangements in the endothelium. In this study, we analyzed in vivo whether these processes require the function of the actin nucleation-promoting factor cortactin. Basal vascular permeability for high molecular weight substances was enhanced in cortactin-deficient mice. Despite this leakiness, neutrophil extravasation in the tumor necrosis factor-stimulated cremaster was inhibited by the loss of cortactin. The permeability defect was caused by reduced levels of activated Rap1 (Ras-related protein 1) in endothelial cells and could be rescued by activating Rap1 via the guanosine triphosphatase (GTPase) exchange factor EPAC (exchange protein directly activated by cAMP). The defect in neutrophil extravasation was caused by enhanced rolling velocity and reduced adhesion in postcapillary venules. Impaired rolling interactions were linked to contributions of β(2)-integrin ligands, and firm adhesion was compromised by reduced ICAM-1 (intercellular adhesion molecule 1) clustering around neutrophils. A signaling process known to be critical for the formation of ICAM-1-enriched contact areas and for transendothelial migration, the ICAM-1-mediated activation of the GTPase RhoG was blocked in cortactin-deficient endothelial cells. Our results represent the first physiological evidence that cortactin is crucial for orchestrating the molecular events leading to proper endothelial barrier function and leukocyte recruitment in vivo.

The role of protein disulfide isomerase in the post-ligation phase of β3 integrin-dependent cell adhesion.

PubMed

Leader, Avi; Mor-Cohen, Ronit; Ram, Ron; Sheptovitsky, Vera; Seligsohn, Uri; Rosenberg, Nurit; Lahav, Judith

2015-12-01

Protein disulfide isomerase (PDI) catalyzes disulfide bond exchange. It is crucial for integrin-mediated platelet adhesion and aggregation and disulfide bond exchange is necessary for αIIbβ3 and αvβ3 activation. However, the role of disulfide bond exchange and PDI in the post-ligation phase of αIIbβ3 and αvβ3 mediated cell adhesion has yet to be determined. To investigate a possible such role, we expressed wild type (WT) human αIIb and either WT human β3, or β3 harboring single or double cysteine to serine substitutions disrupting Cys473-Cys503 or Cys523-Cys544 bonds, in baby hamster kidney (BHK) cells, leading to expression of both human αIIbβ3 and a chimeric hamster/human αvβ3. Adhesion to fibrinogen-coated wells was studied in the presence or absence of bacitracin, a PDI inhibitor, with and without an αvβ3 blocker. Flow cytometry showed WT and mutant αIIbβ3 expression in BHK cells and indicated that mutated αIIbβ3 receptors were constitutively active while WT αIIbβ3 was inactive. Both αIIbβ3 and αvβ3 integrins, WT and mutants, mediated adhesion to fibrinogen as shown by reduced but still substantial adhesion following treatment with the αvβ3 blocker. Mutated αIIbβ3 integrins disrupted in the Cys523-Cys544 bond still depended on PDI for adhesion as shown by the inhibitory effect of bacitracin in the presence of the αvβ3 blocker. Mutated integrins disrupted in the Cys473-Cys503 bond showed a similar trend. PDI-mediated disulfide bond exchange plays a pivotal role in the post-ligation phase of αIIbβ3-mediated adhesion to fibrinogen, while this step in αvβ3-mediated adhesion is independent of disulfide exchange. Copyright © 2015 Elsevier Ltd. All rights reserved.

In vitro analysis of verapamil-induced immunosuppression: potent inhibition of T cell motility and lymphocytic transmigration through allogeneic endothelial cells.

PubMed

Blaheta, R A; Hailer, N P; Brude, N; Wittig, B; Leckel, K; Oppermann, E; Bachmann, M; Harder, S; Cinatl, J; Scholz, M; Bereiter-Hahn, J; Weber, S; Encke, A; Markus, B H

2000-02-27

Cyclosporine A (CsA) and tacrolimus prevent proliferation but not transendothelial migration of alloreactive lymphocytes into donor organs. As a result, serious adverse effects, such as nephrotoxicity and neurotoxicity, have been observed under CsA/tacrolimus therapy. The incorporation of new drugs with infiltration blocking properties might enhance the efficacy of the current immunosuppressive protocol, allowing lower CsA/tacrolimus dosage. Because Ca2+ plays a critical role in cell-cell interaction, the Ca2+-channel blocker verapamil might be a good cany. didate for supporting CsA/tacrolimus-based therapy. A T-cell endothelial cell coculture model or immobilized immunoglobulin G globulin chimeras were employed to investigate how S- and R- verapamil interfere with the lymphocytic infiltration process. The expression and arrangement of membranous adhesion receptors and cytoskeletal F-actin filaments were analyzed by fluorometric method in the presence of. verapamil. Both verapamil enantiomers strongly inhibited lymphocyte infiltration. CD4+ and CD8+ T-cells were influenced to a similar extent with regard to horizontal locomotion (CD4+=CD8+), but to a different extent with regard to adhesion and penetration (CD4+ > CD8+). Moreover, penetration was blocked to a higher extent than was adhesion. ID50-values were 31 microM (CD4+-adhesion) and 11 microM (CD4+-penetration). Verapamil reduced P-selectin expression on endothelial cells and effectively down-regulated binding of T-cells to immobilized P-selectin immunoglobulin G globulins (ID50=4.4 microM; CD4+). A verapamil-induced reduction of intracellular F-actin in T-lymphocytes was proven to be mainly responsible for diminished cell locomotion. The prevention of CD4+ T-cell penetration by verapamil might argue for its use as an adjunct to CsA/tacrolimus-based immunosuppressive therapy.

Platelet-derived chemokines CXC chemokine ligand (CXCL)7, connective tissue-activating peptide III, and CXCL4 differentially affect and cross-regulate neutrophil adhesion and transendothelial migration.

PubMed

Schenk, Birgit I; Petersen, Frank; Flad, Hans-Dieter; Brandt, Ernst

2002-09-01

In this study, we have examined the major platelet-derived CXC chemokines connective tissue-activating peptide III (CTAP-III), its truncation product neutrophil-activating peptide 2 (CXC chemokine ligand 7 (CXCL7)), as well as the structurally related platelet factor 4 (CXCL4) for their impact on neutrophil adhesion to and transmigration through unstimulated vascular endothelium. Using monolayers of cultured HUVEC, we found all three chemokines to promote neutrophil adhesion, while only CXCL7 induced transmigration. Induction of cell adhesion following exposure to CTAP-III, a molecule to date described to lack neutrophil-stimulating capacity, depended on proteolytical conversion of the inactive chemokine into CXCL7 by neutrophils. This was evident from experiments in which inhibition of the CTAP-III-processing protease and simultaneous blockade of the CXCL7 high affinity receptor CXCR-2 led to complete abrogation of CTAP-III-mediated neutrophil adhesion. CXCL4 at substimulatory dosages modulated CTAP-III- as well as CXCL7-induced adhesion. Although cell adhesion following exposure to CTAP-III was drastically reduced, CXCL7-mediated adhesion underwent significant enhancement. Transendothelial migration of neutrophils in response to CXCL7 or IL-8 (CXCL8) was subject to modulation by CTAP-III, but not CXCL4, as seen by drastic desensitization of the migratory response of neutrophils pre-exposed to CTAP-III, which was paralleled by selective down-modulation of CXCR-2. Altogether our results demonstrate that there exist multiple interactions between platelet-derived chemokines in the regulation of neutrophil adhesion and transendothelial migration.

O-sulfated bacterial polysaccharides with low anticoagulant activity inhibit metastasis.

PubMed

Borgenström, Marjut; Wärri, Anni; Hiilesvuo, Katri; Käkönen, Rami; Käkönen, Sanna; Nissinen, Liisa; Pihlavisto, Marjo; Marjamäki, Anne; Vlodavsky, Israel; Naggi, Annamaria; Torri, Giangiacomo; Casu, Benito; Veromaa, Timo; Salmivirta, Markku; Elenius, Klaus

2007-07-01

Heparin-like polysaccharides possess the capacity to inhibit cancer cell proliferation, angiogenesis, heparanase-mediated cancer cell invasion, and cancer cell adhesion to vascular endothelia via adhesion receptors, such as selectins. The clinical applicability of the antitumor effect of such polysaccharides, however, is compromised by their anticoagulant activity. We have compared the potential of chemically O-sulfated and N,O-sulfated bacterial polysaccharide (capsular polysaccharide from E. COLI K5 [K5PS]) species to inhibit metastasis of mouse B16-BL6 melanoma cells and human MDA-MB-231 breast cancer cells in two in vivo models. We demonstrate that in both settings, O-sulfated K5PS was a potent inhibitor of metastasis. Reducing the molecular weight of the polysaccharide, however, resulted in lower antimetastatic capacity. Furthermore, we show that O-sulfated K5PS efficiently inhibited the invasion of B16-BL6 cells through Matrigel and also inhibited the in vitro activity of heparanase. Moreover, treatment with O-sulfated K5PS lowered the ability of B16-BL6 cells to adhere to endothelial cells, intercellular adhesion molecule-1, and P-selectin, but not to E-selectin. Importantly, O-sulfated K5PSs were largely devoid of anticoagulant activity. These findings indicate that O-sulfated K5PS polysaccharide should be considered as a potential antimetastatic agent.

Association of Cell Adhesion Molecules Contactin-6 and Latrophilin-1 Regulates Neuronal Apoptosis

PubMed Central

Zuko, Amila; Oguro-Ando, Asami; Post, Harm; Taggenbrock, Renske L. R. E.; van Dijk, Roland E.; Altelaar, A. F. Maarten; Heck, Albert J. R.; Petrenko, Alexander G.; van der Zwaag, Bert; Shimoda, Yasushi; Pasterkamp, R. Jeroen; Burbach, J. Peter H.

2016-01-01

In view of important neurobiological functions of the cell adhesion molecule contactin-6 (Cntn6) that have emerged from studies on null-mutant mice and autism spectrum disorders patients, we set out to examine pathways underlying functions of Cntn6 using a proteomics approach. We identified the cell adhesion GPCR latrophilin-1 (Lphn1, a.k.a. CIRL1/CL, ADGRL1) as a binding partner for Cntn6 forming together a heteromeric cis-complex. Lphn1 expression in cultured neurons caused reduction in neurite outgrowth and increase in apoptosis, which was rescued by coexpression of Cntn6. In cultured neurons derived from Cntn6-/- mice, Lphn1 knockdown reduced apoptosis, suggesting that the observed apoptosis was Lphn1-dependent. In line with these data, the number of apoptotic cells was increased in the cortex of Cntn6-/- mice compared to wild-type littermate controls. These results show that Cntn6 can modulate the activity of Lphn1 by direct binding and suggests that Cntn6 may prevent apoptosis thereby impinging on neurodevelopment. PMID:28018171

Effect of vacuum thermal annealing on a molybdenum bilayer back contact deposited by radio-frequency magnetron sputtering for chalcogenide- and kesterite-based solar cells

NASA Astrophysics Data System (ADS)

Liu, Xiaolei; Cui, Hongtao; Hao, Xiaojing; Huang, Shujuan; Conibeer, Gavin

2017-12-01

Molybdenum (Mo) thin films are still a dominant choice for the back contact layer of Cu(In,Ga)Se2 (CIGS) and Cu2ZnSnS4 (CZTS) solar cells. This paper presents a review of Mo back contacts for CIGS and CZTS solar cells, including the requirements for a good back contact, the reason for the choice of Mo, and post-treatment. Additionally, a Mo bilayer back contact was fabricated by varying the argon (Ar) pressure during sputtering to provide both low resistivity and good adhesion to the soda-lime glass substrate. The effects of vacuum thermal annealing on the electrical, morphological and structural properties of the Mo bilayer were also investigated. Vacuum thermal annealing was seen to densify the Mo bilayer, reduce the sheet resistance, and improve the bilayer's adhesion to the soda-lime glass. The Mo bilayer back contact with a low sheet resistance of 0.132 Ω/□ and strong adhesion was made for chalcogenide- and kesterite-based solar cells.

Biological adhesion of the flatworm Macrostomum lignano relies on a duo-gland system and is mediated by a cell type-specific intermediate filament protein.

PubMed

Lengerer, Birgit; Pjeta, Robert; Wunderer, Julia; Rodrigues, Marcelo; Arbore, Roberto; Schärer, Lukas; Berezikov, Eugene; Hess, Michael W; Pfaller, Kristian; Egger, Bernhard; Obwegeser, Sabrina; Salvenmoser, Willi; Ladurner, Peter

2014-02-12

Free-living flatworms, in both marine and freshwater environments, are able to adhere to and release from a substrate several times within a second. This reversible adhesion relies on adhesive organs comprised of three cell types: an adhesive gland cell, a releasing gland cell, and an anchor cell, which is a modified epidermal cell responsible for structural support. However, nothing is currently known about the molecules that are involved in this adhesion process. In this study we present the detailed morphology of the adhesive organs of the free-living marine flatworm Macrostomum lignano. About 130 adhesive organs are located in a horse-shoe-shaped arc along the ventral side of the tail plate. Each organ consists of exactly three cells, an adhesive gland cell, a releasing gland cell, and an anchor cell. The necks of the two gland cells penetrate the anchor cell through a common pore. Modified microvilli of the anchor cell form a collar surrounding the necks of the adhesive- and releasing glands, jointly forming the papilla, the outer visible part of the adhesive organs. Next, we identified an intermediate filament (IF) gene, macif1, which is expressed in the anchor cells. RNA interference mediated knock-down resulted in the first experimentally induced non-adhesion phenotype in any marine animal. Specifically, the absence of intermediate filaments in the anchor cells led to papillae with open tips, a reduction of the cytoskeleton network, a decline in hemidesmosomal connections, and to shortened microvilli containing less actin. Our findings reveal an elaborate biological adhesion system in a free-living flatworm, which permits impressively rapid temporary adhesion-release performance in the marine environment. We demonstrate that the structural integrity of the supportive cell, the anchor cell, is essential for this adhesion process: the knock-down of the anchor cell-specific intermediate filament gene resulted in the inability of the animals to adhere. The RNAi mediated changes of the anchor cell morphology are comparable to situations observed in human gut epithelia. Therefore, our current findings and future investigations using this powerful flatworm model system might contribute to a better understanding of the function of intermediate filaments and their associated human diseases.

FES-related tyrosine kinase activates the insulin-like growth factor-1 receptor at sites of cell adhesion.

PubMed

Stanicka, Joanna; Rieger, Leonie; O'Shea, Sandra; Cox, Orla; Coleman, Michael; O'Flanagan, Ciara; Addario, Barbara; McCabe, Nuala; Kennedy, Richard; O'Connor, Rosemary

2018-06-01

IGF-1 receptor (IGF-1R) and integrin cooperative signaling promotes cancer cell survival, proliferation, and motility, but whether this influences cancer progression and therapy responses is largely unknown. Here we investigated the non-receptor tyrosine adhesion kinase FES-related (FER), following its identification as a potential mediator of sensitivity to IGF-1R kinase inhibition in a functional siRNA screen. We found that FER and the IGF-1R co-locate in cells and can be co-immunoprecipitated. Ectopic FER expression strongly enhanced IGF-1R expression and phosphorylation on tyrosines 950 and 1131. FER phosphorylated these sites in an IGF-1R kinase-independent manner and also enhanced IGF-1-mediated phosphorylation of SHC, and activation of either AKT or MAPK-signaling pathways in different cells. The IGF-1R, β1 Integrin, FER, and its substrate cortactin were all observed to co-locate in cell adhesion complexes, the disruption of which reduced IGF-1R expression and activity. High FER expression correlates with phosphorylation of SHC in breast cancer cell lines and with a poor prognosis in patient cohorts. FER and SHC phosphorylation and IGF-1R expression could be suppressed with a known anaplastic lymphoma kinase inhibitor (AP26113) that shows high specificity for FER kinase. Overall, we conclude that FER enhances IGF-1R expression, phosphorylation, and signaling to promote cooperative growth and adhesion signaling that may facilitate cancer progression.

[Expression of cell adhesion molecules in acute leukemia cell].

PubMed

Ju, Xiaoping; Peng, Min; Xu, Xiaoping; Lu, Shuqing; Li, Yao; Ying, Kang; Xie, Yi; Mao, Yumin; Xia, Fang

2002-11-01

To investigate the role of cell adhesion molecule in the development and extramedullary infiltration (EI) of acute leukemia. The expressions of neural cell adhesion molecule (NCAM) gene, intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule (VCAM-1) genes in 25 acute leukemia patients bone marrow cells were detected by microarray and reverse transcriptase-polymerase chain reaction (RT-PCR). The expressions of NCAM, ICAM-1 and VCAM-1 gene were significantly higher in acute leukemia cells and leukemia cells with EI than in normal tissues and leukemia cells without EI, respectively, both by cDNA microarray and by RT-PCR. The cDNA microarray is a powerful technique in analysis of acute leukemia cells associated genes. High expressions of cell adhesion molecule genes might be correlated with leukemia pathogenesis and infiltration of acute leukemia cell.

Adhesion and splash dispersal of Salmonella enterica Typhimurium on tomato leaflets: effects of rdar morphotype and trichome density.

PubMed

Cevallos-Cevallos, Juan M; Gu, Ganyu; Danyluk, Michelle D; van Bruggen, Ariena H C

2012-11-01

Salmonella enterica strains with rdar (red dry and rough) and saw (smooth and white) morphotypes have previously been associated with tomato outbreaks but the dispersal mechanisms of these morphotypes are still poorly understood. In this study, Salmonella adhesion was distinguished from attachment by comparing different contact periods. Initial adhesion of rdar and saw morphotypes of Salmonella was compared in relation to tomato plants with different leaf trichome densities. Trichome densities were increased or reduced by treatment with jasmonic or salicylic acid, respectively. The overall effect of Salmonella morphotype and trichome density on splash dispersal was assessed in a rain simulator and correlated to cell hydrophobicity and initial adhesion. The presence of the rdar morphotype increased initial adhesion at high trichome densities but not at low trichome densities. Attachment of the rdar strain occurred after 30s contact time regardless of trichome density. Splash dispersal was slightly further for the saw morphotype than the rdar morphotype of S. enterica at all trichome densities. Salmonella cells of both morphotypes survived significantly better on the surface of high trichome density leaflets. Copyright © 2012 Elsevier B.V. All rights reserved.

Theory and simulations of adhesion receptor dimerization on membrane surfaces.

PubMed

Wu, Yinghao; Honig, Barry; Ben-Shaul, Avinoam

2013-03-19

The equilibrium constants of trans and cis dimerization of membrane bound (2D) and freely moving (3D) adhesion receptors are expressed and compared using elementary statistical-thermodynamics. Both processes are mediated by the binding of extracellular subdomains whose range of motion in the 2D environment is reduced upon dimerization, defining a thin reaction shell where dimer formation and dissociation take place. We show that the ratio between the 2D and 3D equilibrium constants can be expressed as a product of individual factors describing, respectively, the spatial ranges of motions of the adhesive domains, and their rotational freedom within the reaction shell. The results predicted by the theory are compared to those obtained from a novel, to our knowledge, dynamical simulations methodology, whereby pairs of receptors perform realistic translational, internal, and rotational motions in 2D and 3D. We use cadherins as our model system. The theory and simulations explain how the strength of cis and trans interactions of adhesive receptors are affected both by their presence in the constrained intermembrane space and by the 2D environment of membrane surfaces. Our work provides fundamental insights as to the mechanism of lateral clustering of adhesion receptors after cell-cell contact and, more generally, to the formation of lateral microclusters of proteins on cell surfaces. Copyright © 2013 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Low-calorie cranberry juice supplementation reduces plasma oxidized LDL and cell adhesion molecule concentrations in men.

PubMed

Ruel, Guillaume; Pomerleau, Sonia; Couture, Patrick; Lemieux, Simone; Lamarche, Benoît; Couillard, Charles

2008-02-01

Elevated circulating concentrations of oxidized LDL (OxLDL) and cell adhesion molecules are considered to be relevant markers of oxidative stress and endothelial activation which are implicated in the development of CVD. On the other hand, it has been suggested that dietary flavonoid consumption may be cardioprotective through possible favourable impacts on LDL particle oxidation and endothelial activation. The present study was undertaken to determine the effect of the daily consumption of low-calorie cranberry juice cocktail on plasma OxLDL, intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and E-selectin concentrations in men. Thirty men (mean age 51 (sd 10) years) were recruited and asked to consume increasing daily doses of cranberry juice cocktail (125, 250 and 500 ml/d) over three successive periods of 4 weeks. Plasma OxLDL and adhesion molecule concentrations were measured by ELISA before and after each phase. We noted a significant decrease in plasma OxLDL concentrations following the intervention (P < 0.0001). We also found that plasma ICAM-1 (P < 0.0001) and VCAM-1 (P < 0.05) concentrations decreased significantly during the course of the study. In summary, the present results show that daily cranberry juice cocktail consumption is associated with decreases in plasma OxLDL, ICAM-1 and VCAM-1 concentrations in men.

Morphing hybrid honeycomb (MOHYCOMB) with in situ Poisson’s ratio modulation

NASA Astrophysics Data System (ADS)

Heath, Callum J. C.; Neville, Robin M.; Scarpa, Fabrizio; Bond, Ian P.; Potter, Kevin D.

2016-08-01

Electrostatic adhesion can be used as a means of reversible attachment. Through application of high voltage (~2 kV) across closely spaced parallel plate electrodes, significant shear stresses (11 kPa) can be generated. The highest levels of electrostatic holding force can be achieved through close contact of connection surfaces; this is facilitated by flexible electrodes which can conform to reduce air gaps. Cellular structures are comprised of thin walled elements, making them ideal host structures for electrostatic adhesive elements. The reversible adhesion provides control of the internal connectivity of the cellular structure, and determines the effective cell geometry. This would offer variable stiffness and control of the effective Poisson’s ratio of the global cellular array. Using copper-polyimide thin film laminates and PVDF thin film dielectrics, double lap shear electrostatic adhesive elements have been introduced to a cellular geometry. By activating different groups of reversible adhesive interfaces, the cellular array can assume four different cell configurations. A maximum stiffness modulation of 450% between the ‘All off’ and ‘All on’ cell morphologies has been demonstrated. This structure is also capable of in situ effective Poisson’s ratio variations, with the ability to switch between values of -0.45 and 0.54. Such a structure offers the potential for tuneable vibration absorption (due to its variable stiffness properties), or as a smart honeycomb with controllable curvature and is termed morphing hybrid honeycomb.

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

PubMed

Dickreuter, Ellen; Cordes, Nils

2017-06-27

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

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

PubMed

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

2014-12-18

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

Loss of membranous Ep-CAM in budding colorectal carcinoma cells.

PubMed

Gosens, Marleen J E M; van Kempen, Léon C L; van de Velde, Cornelis J H; van Krieken, J Han J M; Nagtegaal, Iris D

2007-02-01

Tumor budding is a histological feature that reflects loss of adhesion of tumor cells and is associated with locoregional metastasis of colorectal carcinoma. Although nuclear localization of beta-catenin is associated with tumor budding, the molecular mechanism remains largely elusive. In this study, we hypothesize that the epithelial cell adhesion molecule (Ep-CAM) is involved in tumor budding. In order to address this question, we performed immunohistochemistry on Ep-CAM using three different antibodies (monoclonal antibodies Ber-ep4 and 311-1K1 and a polyclonal antibody) and a double staining on beta-catenin and Ep-CAM. In addition, Ep-CAM mRNA was monitored with mRNA in situ hybridization. Subsequently, we determined the effect of Ep-CAM staining patterns on tumor spread in rectal cancer. In contrast to the tumor mass, budding cells of colorectal carcinoma displayed lack of membranous but highly increased cytoplasmic Ep-CAM staining and nuclear translocation of beta-catenin. mRNA in situ hybridization suggested no differences in Ep-CAM expression between the invasive front and the tumor mass. Importantly, reduced Ep-CAM staining at the invasive margin of rectal tumor specimens (n=133) correlated significantly with tumor budding, tumor grade and an increased risk of local recurrence (P=0.001, P=0.04 and P=0.03, respectively). These data demonstrate abnormal processing of Ep-CAM at the invasive margin of colorectal carcinomas. Our observations indicate that loss of membranous Ep-CAM is associated with nuclear beta-catenin localization and suggest that this contributes to reduced cell-cell adhesions, increased migratory potential and tumor budding.

Mechanisms of peripheral immune-cell-mediated analgesia in inflammation: clinical and therapeutic implications.

PubMed

Hua, Susan; Cabot, Peter J

2010-09-01

Peripheral mechanisms of endogenous pain control are significant. In peripheral inflamed tissue, an interaction between immune-cell-derived opioids and opioid receptors localized on sensory nerve terminals results in potent, clinically measurable analgesia. Opioid peptides and the mRNA encoding their precursor proteins are present in immune cells. These cells 'home' preferentially to injured tissue, where they secrete opioids to reduce pain. Investigation of the mechanisms underlying the migration of opioid-containing immune cells to inflamed tissue is an active area of research, with recent data demonstrating the importance of cell adhesion molecules in leukocyte adhesion to both the endothelium in vascular transmigration and to neurons within peripheral inflamed tissue. This review summarizes the physiological mechanisms and clinical significance of this unique endogenous peripheral analgesic pathway and discusses therapeutic implications for the development of novel targeted peripheral analgesics. Copyright 2010 Elsevier Ltd. All rights reserved.

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

PubMed Central

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

2002-01-01

The extra-enzymic function of cell-surface adenosine deaminase (ADA), an enzyme mainly localized in the cytosol but also found on the cell surface of monocytes, B cells and T cells, has lately been the subject of numerous studies. Cell-surface ADA is able to transduce co-stimulatory signals in T cells via its interaction with CD26, an integral membrane protein that acts as ADA-binding protein. The aim of the present study was to explore whether ADA-CD26 interaction plays a role in the adhesion of lymphocyte cells to human epithelial cells. To meet this aim, different lymphocyte cell lines (Jurkat and CEM T) expressing endogenous, or overexpressing human, CD26 protein were tested in adhesion assays to monolayers of colon adenocarcinoma human epithelial cells, Caco-2, which express high levels of cell-surface ADA. Interestingly, the adhesion of Jurkat and CEM T cells to a monolayer of Caco-2 cells was greatly dependent on CD26. An increase by 50% in the cell-to-cell adhesion was found in cells containing higher levels of CD26. Incubation with an anti-CD26 antibody raised against the ADA-binding site or with exogenous ADA resulted in a significant reduction (50-70%) of T-cell adhesion to monolayers of epithelial cells. The role of ADA-CD26 interaction in the lymphocyte-epithelial cell adhesion appears to be mediated by CD26 molecules that are not interacting with endogenous ADA (ADA-free CD26), since SKW6.4 (B cells) that express more cell-surface ADA showed lower adhesion than T cells. Adhesion stimulated by CD26 and ADA is mediated by T cell lymphocyte function-associated antigen. A role for ADA-CD26 interaction in cell-to-cell adhesion was confirmed further in integrin activation assays. FACS analysis revealed a higher expression of activated integrins on T cell lines in the presence of increasing amounts of exogenous ADA. Taken together, these results suggest that the ADA-CD26 interaction on the cell surface has a role in lymphocyte-epithelial cell adhesion. PMID:11772392

Assay for adhesion and agar invasion in S. cerevisiae.

PubMed

Guldal, Cemile G; Broach, James

2006-11-08

Yeasts are found in natural biofilms, where many microorganisms colonize surfaces. In artificial environments, such as surfaces of man-made objects, biofilms can reduce industrial productivity, destroy structures, and threaten human life. 1-3 On the other hand, harnessing the power of biofilms can help clean the environment and generate sustainable energy. 4-8 The ability of S. cerevisiae to colonize surfaces and participate in complex biofilms was mostly ignored until the rediscovery of the differentiation programs triggered by various signaling pathways and environmental cues in this organism. 9, 10 The continuing interest in using S. cerevisiae as a model organism to understand the interaction and convergence of signaling pathways, such as the Ras-PKA, Kss1 MAPK, and Hog1 osmolarity pathways, quickly placed S. cerevisiae in the junction of biofilm biology and signal transduction research. 11-20 To this end, differentiation of yeast cells into long, adhesive, pseudohyphal filaments became a convenient readout for the activation of signal transduction pathways upon various environmental changes. However, filamentation is a complex collection of phenotypes, which makes assaying for it as if it were a simple phenotype misleading. In the past decade, several assays were successfully adopted from bacterial biofilm studies to yeast research, such as MAT formation assays to measure colony spread on soft agar and crystal violet staining to quantitatively measure cell-surface adherence. 12, 21 However, there has been some confusion in assays developed to qualitatively assess the adhesive and invasive phenotypes of yeast in agar. Here, we present a simple and reliable method for assessing the adhesive and invasive quality of yeast strains with easy-to-understand steps to isolate the adhesion assessment from invasion assessment. Our method, adopted from previous studies, 10, 16 involves growing cells in liquid media and plating on differential nutrient conditions for growth of large spots, which we then wash with water to assess adhesion and rub cells completely off the agar surface to assess invasion into the agar. We eliminate the need for streaking cells onto agar, which affects the invasion of cells into the agar. In general, we observed that haploid strains that invade agar are always adhesive, yet not all adhesive strains can invade agar medium. Our approach can be used in conjunction with other assays to carefully dissect the differentiation steps and requirements of yeast signal transduction, differentiation, quorum sensing, and biofilm formation.

Assay for Adhesion and Agar Invasion in S. cerevisiae

PubMed Central

Guldal, Cemile G; Broach, James

2006-01-01

Yeasts are found in natural biofilms, where many microorganisms colonize surfaces. In artificial environments, such as surfaces of man-made objects, biofilms can reduce industrial productivity, destroy structures, and threaten human life. 1-3 On the other hand, harnessing the power of biofilms can help clean the environment and generate sustainable energy. 4-8 The ability of S. cerevisiae to colonize surfaces and participate in complex biofilms was mostly ignored until the rediscovery of the differentiation programs triggered by various signaling pathways and environmental cues in this organism. 9, 10 The continuing interest in using S. cerevisiae as a model organism to understand the interaction and convergence of signaling pathways, such as the Ras-PKA, Kss1 MAPK, and Hog1 osmolarity pathways, quickly placed S. cerevisiae in the junction of biofilm biology and signal transduction research. 11-20 To this end, differentiation of yeast cells into long, adhesive, pseudohyphal filaments became a convenient readout for the activation of signal transduction pathways upon various environmental changes. However, filamentation is a complex collection of phenotypes, which makes assaying for it as if it were a simple phenotype misleading. In the past decade, several assays were successfully adopted from bacterial biofilm studies to yeast research, such as MAT formation assays to measure colony spread on soft agar and crystal violet staining to quantitatively measure cell-surface adherence. 12, 21 However, there has been some confusion in assays developed to qualitatively assess the adhesive and invasive phenotypes of yeast in agar. Here, we present a simple and reliable method for assessing the adhesive and invasive quality of yeast strains with easy-to-understand steps to isolate the adhesion assessment from invasion assessment. Our method, adopted from previous studies, 10, 16 involves growing cells in liquid media and plating on differential nutrient conditions for growth of large spots, which we then wash with water to assess adhesion and rub cells completely off the agar surface to assess invasion into the agar. We eliminate the need for streaking cells onto agar, which affects the invasion of cells into the agar. In general, we observed that haploid strains that invade agar are always adhesive, yet not all adhesive strains can invade agar medium. Our approach can be used in conjunction with other assays to carefully dissect the differentiation steps and requirements of yeast signal transduction, differentiation, quorum sensing, and biofilm formation. PMID:18704175

Morphological Observations of Mesenchymal Stem Cell Adhesion to a Nanoperiodic-Structured Titanium Surface Patterned Using Femtosecond Laser Processing

NASA Astrophysics Data System (ADS)

Oya, Kei; Aoki, Shun; Shimomura, Kazunori; Sugita, Norihiko; Suzuki, Kenji; Nakamura, Norimasa; Fujie, Hiromichi

2012-12-01

It is known that the adhesive and anisotropic properties of cell-derived biomaterials are affected by micro- or nanoscale structures processed on culture surfaces. In the present study, the femtosecond laser processing technique was used to scan a laser beam at an intensity of approximately the ablation threshold level on a titanium surface for nanoscale processing. Microscopy observation revealed that the processed titanium exhibited a periodic-patterned groove structure at the surface; the width and depth of the groove were 292 ±50 and 99 ±31 nm, respectively, and the periodic pitch of the groove was 501 ±100 nm. Human synovium-derived mesenchymal stem cells were cultured on the surface at a cell density of 3.0×103 cells/cm2 after 4 cell passages. For comparison, the cells were also cultured on a nonprocessed titanium surface under the condition identical to that of the processed surface. Results revealed that the duration for cell attachment to the surface was markedly reduced on the processed titanium as compared with the nonprocessed titanium. Moreover, on the processed titanium, cell extension area significantly increased while cell orientation was aligned along the direction of the periodic grooves. These results suggest that the femtosecond laser processing improves the adhesive and anisotropic properties of cells by producing the nanoperiodic structure on titanium culture surfaces.

Disruption of Annexin II /p11 Interaction Suppresses Leukemia Cell Binding, Homing and Engraftment, and Sensitizes the Leukemia Cells to Chemotherapy.

PubMed

Gopalakrishnapillai, Anilkumar; Kolb, E Anders; Dhanan, Priyanka; Mason, Robert W; Napper, Andrew; Barwe, Sonali P

2015-01-01

The bone marrow microenvironment plays an important role in acute lymphoblastic leukemia (ALL) cell proliferation, maintenance, and resistance to chemotherapy. Annexin II (ANX2) is abundantly expressed on bone marrow cells and complexes with p11 to form ANX2/p11-hetero-tetramer (ANX2T). We present evidence that p11 is upregulated in refractory ALL cell lines and patient samples. A small molecule inhibitor that disrupts ANX2/p11 interaction (ANX2T inhibitor), an anti-ANX2 antibody, and knockdown of p11, abrogated ALL cell adhesion to osteoblasts, indicating that ANX2/p11 interaction facilitates binding and retention of ALL cells in the bone marrow. Furthermore, ANX2T inhibitor increased the sensitivity of primary ALL cells co-cultured with osteoblasts to dexamethasone and vincristine induced cell death. Finally, in an orthotopic leukemia xenograft mouse model, the number of ALL cells homing to the bone marrow was reduced by 40-50% in mice injected with anti-ANX2 antibody, anti-p11 antibody or ANX2T inhibitor compared to respective controls. In a long-term engraftment assay, the percentage of ALL cells in mouse blood, bone marrow and spleen was reduced in mice treated with agents that disrupt ANX2/p11 interaction. These data show that disruption of ANX2/p11 interaction results in reduced ALL cell adhesion to osteoblasts, increased ALL cell sensitization to chemotherapy, and suppression of ALL cell homing and engraftment.

Low-expression of E-cadherin in leukaemia cells causes loss of homophilic adhesion and promotes cell growth.

PubMed

Rao, Qing; Wang, Ji-Ying; Meng, Jihong; Tang, Kejing; Wang, Yanzhong; Wang, Min; Xing, Haiyan; Tian, Zheng; Wang, Jianxiang

2011-09-01

E-cadherin (epithelial cadherin) belongs to the calcium-dependent adhesion molecule superfamily and is implicated in the interactions of haematopoietic progenitors and bone marrow stromal cells. Adhesion capacity to bone marrow stroma was impaired for leukaemia cells, suggesting that a breakdown of adhesive mechanisms governed by an adhesion molecule may exist in leukaemic microenvironment. We previously found that E-cadherin was low expressed in primary acute leukaemia cells compared with normal bone marrow mononuclear cells. In this study, we investigate the functional importance of low E-cadherin expression in leukaemia cell behaviours and investigate its effects in the abnormal interaction of leukaemic cells with stromal cells. After expression of E-cadherin was restored by a demethylating agent in leukaemia cells, E-cadherin-specific adhesion was enhanced. Additionally, siRNA (small interfering RNA)-mediated silencing of E-cadherin in Raji cells resulted in a reduction of cell homophilic adhesion and enhancement of cell proliferation and colony formation. These results suggest that low expression of E-cadherin contributes to the vigorous growth and transforming ability of leukaemic cells.

Diffusion and intermembrane distance: case study of avidin and E-cadherin mediated adhesion.

PubMed

Fenz, Susanne F; Merkel, Rudolf; Sengupta, Kheya

2009-01-20

We present a biomimetic model system for cell-cell adhesion consisting of a giant unilamellar vesicle (GUV) adhering via specific ligand-receptor interactions to a supported lipid bilayer (SLB). The modification of in-plane diffusion of tracer lipids and receptors in the SLB membrane due to adhesion to the GUV is reported. Adhesion was mediated by either biotin-neutravidin (an avidin analogue) or the extracellular domains of the cell adhesion molecule E-cadherin (Ecad). In the strong interaction (biotin-avidin) case, binding of soluble receptors to the SLB alone led to reduced diffusion of tracer lipids. From theoretical considerations, this could be attributed partially to introduction of obstacles and partially to viscous effects. Further specific binding of a GUV membrane caused additional slowing down of tracers (up to 15%) and immobilization of receptors, and led to accumulation of receptors in the adhesion zone until full coverage was achieved. The intermembrane distance was measured to be 7 nm from microinterferometry (RICM). We show that a crowding effect due to the accumulated receptors alone is not sufficient to account for the slowing downan additional friction from the membrane also plays a role. In the weak binding case (Ecad), the intermembrane distance was about 50 nm, corresponding to partial overlap of the Ecad domains. No significant change in diffusion of tracer lipids was observed upon either protein binding or subsequent vesicle binding. The former was probably due to very small effective size of the obstacles introduced into the bilayer by Ecad binding, whereas the latter was due to the fact that, with such high intermembrane distance, the resulting friction is negligible. We conclude that the effect of intermembrane adhesion on diffusion depends strongly on the choice of the receptors.

Heat shock proteins HSP70 and MRJ cooperatively regulate cell adhesion and migration through urokinase receptor.

PubMed

Lin, Yuli; Peng, Nana; Zhuang, Hongqin; Zhang, Di; Wang, Yao; Hua, Zi-Chun

2014-08-30

The urokinase-type plasminogen activator receptor (uPAR) is an important regulator of ECM proteolysis, cell-ECM interactions and cell signaling. uPAR and heat shock proteins HSP70 and MRJ (DNAJB6) have been implicated in tumor growth and metastasis. We have reported recently that MRJ (DNAJB6, a heat shock protein) can interact with uPAR and enhance cell adhesion. Here, we identified another heat shock protein HSP70 as a novel uPAR-interacting protein. We performed co-immunoprecipitation in human embryonic kidney (HEK) 293 and colon cancer HCT116 cells as well as immunofluorence assays in HEK293 cells stably transfected with uPAR to investigate the association of suPAR with HSP70/MRJ. To understand the biological functions of the triple complex of suPAR/HSP70/MRJ, we determined whether HSP70 and/or MRJ regulated uPAR-mediated cell invasion, migration, adhesion to vitronectin and MAPK pathway in two pair of human tumor cells (uPAR negative HEK293 cells vs HEK293 cells stably transfected with uPAR and HCT116 cells stably transfected with antisense-uPAR vs HCT116 mock cells transfected with vector only) using transwell assay, wound healing assay, quantitative RT-PCR analyzing mmp2 and mmp9 transcription levels, cell adhesion assay and Western blotting assay. HSP70 and MRJ formed a triple complex with uPAR and over-expression of MRJ enhanced the interaction between HSP70 and uPAR, while knockdown of MRJ decreased soluble uPAR in HCT116 cells (P < 0.05) and reduced the formation of the triple complex, suggesting that MRJ may act as an uPAR-specific adaptor protein to link uPAR to HSP70. Further experiments showed that knockdown of HSP70 and/or MRJ by siRNA inhibited uPAR-mediated cell adhesion to vitronectin as well as suppressed cell invasion and migration. Knockdown of HSP70 and/or MRJ inhibited expression of invasion related genes mmp2 and mmp9. Finally, HSP70 and/or MRJ up-regulated phosphorylation levels of ERK1/2 and FAK suggesting MAPK pathway was involved. All the biological function experiments in cell level showed an additive effect when HSP70 and MRJ were regulated simultaneously indicating their collaborated regulation effects on uPAR. These findings may offer a novel insight into the interactions between uPAR and HSP70/MRJ and their functions in cell adhesion and migration may provide more understanding of the roles in regulating cancer metastasis.

Cellular level robotic surgery: Nanodissection of intermediate filaments in live keratinocytes.

PubMed

Yang, Ruiguo; Song, Bo; Sun, Zhiyong; Lai, King Wai Chiu; Fung, Carmen Kar Man; Patterson, Kevin C; Seiffert-Sinha, Kristina; Sinha, Animesh A; Xi, Ning

2015-01-01

We present the nanosurgery on the cytoskeleton of live cells using AFM based nanorobotics to achieve adhesiolysis and mimic the effect of pathophysiological modulation of intercellular adhesion. Nanosurgery successfully severs the intermediate filament bundles and disrupts cell-cell adhesion similar to the desmosomal protein disassembly in autoimmune disease, or the cationic modulation of desmosome formation. Our nanomechanical analysis revealed that adhesion loss results in a decrease in cellular stiffness in both cases of biochemical modulation of the desmosome junctions and mechanical disruption of intercellular adhesion, supporting the notion that intercellular adhesion through intermediate filaments anchors the cell structure as focal adhesion does and that intermediate filaments are integral components in cell mechanical integrity. The surgical process could potentially help reveal the mechanism of autoimmune pathology-induced cell-cell adhesion loss as well as its related pathways that lead to cell apoptosis. Copyright © 2015 Elsevier Inc. All rights reserved.

Endothelial NOS is required for SDF-1alpha/CXCR4-mediated peripheral endothelial adhesion of c-kit+ bone marrow stem cells.

PubMed

Kaminski, Alexander; Ma, Nan; Donndorf, Peter; Lindenblatt, Nicole; Feldmeier, Gregor; Ong, Lee-Lee; Furlani, Dario; Skrabal, Christian A; Liebold, Andreas; Vollmar, Brigitte; Steinhoff, Gustav

2008-01-01

In the era of intravascular approaches for regenerative cell therapy, the underlying mechanisms of stem cell migration to non-marrow tissue have not been clarified. We hypothesized that next to a local inflammatory response implying adhesion molecule expression, endothelial nitric oxide synthase (eNOS)-dependent signaling is required for stromal- cell-derived factor-1 alpha (SDF-1alpha)-induced adhesion of c-kit+ cells to the vascular endothelium. SDF-1alpha/tumor necrosis factor-alpha (TNF-alpha)-induced c-kit+-cell shape change and migration capacity was studied in vitro using immunohistochemistry and Boyden chamber assays. In vivo interaction of c-kit+ cells from bone marrow with the endothelium in response to SDF-1alpha/TNF-alpha stimulation was visualized in the cremaster muscle microcirculation of wild-type (WT) and eNOS (-/-) mice using intravital fluorescence microscopy. In addition, NOS activity was inhibited with N-nitro-L-arginine-methylester-hydrochloride in WT mice. To reveal c-kit+-specific adhesion behavior, endogenous leukocytes (EL) and c-kit+ cells from peripheral blood served as control. Moreover, intercellular adhesion molecule-1 (ICAM-1) and CXCR4 were blocked systemically to determine their role in inflammation-related c-kit+-cell adhesion. In vitro, SDF-1alpha enhanced c-kit+-cell migration. In vivo, SDF-1alpha alone triggered endothelial rolling-not firm adherence-of c-kit+ cells in WT mice. While TNF-alpha alone had little effect on adhesion of c-kit+ cells, it induced maximum endothelial EL adherence. However, after combined treatment with SDF-1alpha+TNF-alpha, endothelial adhesion of c-kit+ cells increased independent of their origin, while EL adhesion was not further incremented. Systemic treatment with anti-ICAM-1 and anti-CXCR4-monoclonal antibody completely abolished endothelial c-kit+-cell adhesion. In N-nitro-L-arginine-methylester-hydrochloride-treated WT mice as well as in eNOS (-/-) mice, firm endothelial adhesion of c-kit+ cells was entirely abrogated, while EL adhesion was significantly increased. The chemokine SDF-1alpha mediates firm adhesion c-kit+ cells only in the presence of TNF-alpha stimulation via an ICAM-1- and CXCR4-dependent mechanism. The presence of eNOS appears to be a crucial and specific factor for firm c-kit+-cell adhesion to the vascular endothelium.

Adhesion to brown trout skin mucus, antagonism against cyst adhesion and pathogenicity to rainbow trout of some inhibitory bacteria against Saprolegnia parasitica .

PubMed

Carbajal-González, M T; Fregeneda-Grandes, J M; González-Palacios, C; Aller-Gancedo, J M

2013-04-29

Biological control of saprolegniosis with bacteria might be an alternative to the use of chemical compounds. Among criteria for the selection of such bacteria are their absence of pathogenicity to fish and their ability to prevent adhesion of the pathogen to the skin mucus. The pathogenicity to rainbow trout of 21 bacterial isolates with in vitro inhibitory activity against Saprolegnia parasitica was studied. Fifteen of the isolates, identified as Aeromonas sobria, Pantoea agglomerans, Pseudomonas fluorescens, Serratia fonticola, Xanthomonas retroflexus and Yersinia kristensenii, were non-pathogenic when injected into rainbow trout. Their capacity to adhere to the skin mucus of male and female brown trout and to reduce the adhesion of S. parasitica cysts under exclusion, competition and displacement conditions was tested. The 15 bacterial isolates showed a low adhesion rate, ranging between 1.7% (for an A. sobria isolate) and 15.3% (a P. fluorescens isolate). This adhesion was greater in the case of mucus from male brown trout than from females. Similarities in the adhesion to male mucus and other substrates and correlation to that observed to polystyrene suggest that adhesion to skin mucus does not depend on the substrate. A high percentage (88.9%) of the S. parasitica cysts adhered to the skin mucus of male brown trout. Almost all of the bacteria reduced this adhesion ratio significantly under exclusion and competition conditions. However, only half of the isolates displaced cysts from skin mucus, and more bacterial cells were necessary for this effect. A novel method to study the adhesion of S. parasitica cysts to skin mucus of trout and their interactions with inhibitory bacteria is described.

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

PubMed

Sergé, Arnauld

2016-01-01

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

Biofouling in photobioreactors for marine microalgae.

PubMed

Zeriouh, Ouassim; Reinoso-Moreno, José Vicente; López-Rosales, Lorenzo; Cerón-García, María Del Carmen; Sánchez-Mirón, Asterio; García-Camacho, Francisco; Molina-Grima, Emilio

2017-12-01

The economic and/or energetic feasibility of processes based on using microalgae biomass requires an efficient cultivation system. In photobioreactors (PBRs), the adhesion of microalgae to the transparent PBR surfaces leads to biofouling and reduces the solar radiation penetrating the PBR. Light reduction within the PBR decreases biomass productivity and, therefore, the photosynthetic efficiency of the cultivation system. Additionally, PBR biofouling leads to a series of further undesirable events including changes in cell pigmentation, culture degradation, and contamination by invasive microorganisms; all of which can result in the cultivation process having to be stopped. Designing PBR surfaces with proper materials, functional groups or surface coatings, to prevent microalgal adhesion is essential for solving the biofouling problem. Such a significant advance in microalgal biotechnology would enable extended operational periods at high productivity and reduce maintenance costs. In this paper, we review the few systematic studies performed so far and applied the existing thermodynamic and colloidal theories for microbial biofouling formation in order to understand microalgal adhesion on PBR surfaces and the microalgae-microalgae cell interactions. Their relationship to the physicochemical properties of the solid PBR surface, the microalgae cell surfaces, and the ionic strength of the culture medium is discussed. The suitability and the applicability of such theories are reviewed. To this end, an example of biofouling formation on a commercial glass surface is presented for the marine microalgae Nannochloropsis gaditana. It highlights the adhesion dynamics and the inaccuracies of the process and the need for further refinement of previous theories so as to apply them to flowing systems, such as is the case for PBRs used to culture microalgae.

A new role of the Rac-GAP β2-chimaerin in cell adhesion reveals opposite functions in breast cancer initiation and tumor progression

PubMed Central

Casado-Medrano, Victoria; Barrio-Real, Laura; García-Rostán, Ginesa; Baumann, Matti; Rocks, Oliver; Caloca, María J.

2016-01-01

β2-chimaerin is a Rac1-specific negative regulator and a candidate tumor suppressor in breast cancer but its precise function in mammary tumorigenesis in vivo is unknown. Here, we study for the first time the role of β2-chimaerin in breast cancer using a mouse model and describe an unforeseen role for this protein in epithelial cell-cell adhesion. We demonstrate that expression of β2-chimaerin in breast cancer epithelial cells reduces E-cadherin protein levels, thus loosening cell-cell contacts. In vivo, genetic ablation of β2-chimaerin in the MMTV-Neu/ErbB2 mice accelerates tumor onset, but delays tumor progression. Finally, analysis of clinical databases revealed an inverse correlation between β2-chimaerin and E-cadherin gene expressions in Her2+ breast tumors. Furthermore, breast cancer patients with low β2-chimaerin expression have reduced relapse free survival but develop metastasis at similar times. Overall, our data redefine the role of β2-chimaerin as tumor suppressor and provide the first in vivo evidence of a dual function in breast cancer, suppressing tumor initiation but favoring tumor progression. PMID:27058424

In vitro effects of Salvia officinalis L. essential oil on Candida albicans

PubMed Central

Sookto, Tularat; Srithavaj, Theerathavaj; Thaweboon, Sroisiri; Thaweboon, Boonyanit; Shrestha, Binit

2013-01-01

Objective To determine the anticandidal activities of Salvia officinalis L. (S. officinalis) essential oil against Candida albicans (C. albicans) and the inhibitory effects on the adhesion of C. albicans to polymethyl methacrylate (PMMA) resin surface. Methods Disc diffusion method was first used to test the anticandidal activities of the S. officinalis L. essential oil against the reference strain (ATCC 90028) and 2 clinical strains of C. albicans. Then the minimal inhibitory concentration (MIC) and minimal lethal concentration (MLC) were determined by modified membrane method. The adhesion of C. albicans to PMMA resin surface was assessed after immersion with S. officinalis L. essential oil at various concentrations of 1×MIC, 0.5×MIC and 0.25×MIC at room temperature for 30 min. One-way ANOVA was used to compare the Candida cell adhesion with the pretreatment agents and Tukey's test was used for multiple comparisons. Results S. officinalis L. essential oil exhibited anticandidal activity against all strains of C. albicans with inhibition zone ranging from 40.5 mm to 19.5 mm. The MIC and MLC of the oil were determined as 2.780 g/L against all test strains. According to the effects on C. albicans adhesion to PMMA resin surface, it was found that immersion in the essential oil at concentrations of 1×MIC (2.780 g/L), 0.5×MIC (1.390 g/L) and 0.25×MIC (0.695 g/L) for 30 min significantly reduced the adhesion of all 3 test strains to PMMA resin surface in a dose dependent manner (P<0.05). Conclusions S. officinalis L. essential oil exhibited anticandidal activities against C. albicans and had inhibitory effects on the adhesion of the cells to PMMA resin surface. With further testing and development, S. officinalis essential oil may be used as an antifungal denture cleanser to prevent candidal adhesion and thus reduce the risk of candida-associated denture stomatitis. PMID:23646301

RAFTK, a novel member of the focal adhesion kinase family, is phosphorylated and associates with signaling molecules upon activation of mature T lymphocytes.

PubMed

Ganju, R K; Hatch, W C; Avraham, H; Ona, M A; Druker, B; Avraham, S; Groopman, J E

1997-03-17

The related adhesion focal tyrosine kinase (RAFTK), a recently discovered member of the focal adhesion kinase family, has previously been reported to participate in signal transduction in neuronal cells, megakaryocytes, and B lymphocytes. We have found that RAFTK is constitutively expressed in human T cells and is rapidly phosphorylated upon the activation of the T cell receptor (TCR). This activation also results in an increase in the autophosphorylation and kinase activity of RAFTK. After its stimulation, there was an increase in the association of the src cytoplasmic tyrosine kinase Fyn and the adapter protein Grb2. This association was mediated through the SH2 domains of Fyn and Grb2. RAFTK also co-immunoprecipitates with the SH2 domain of Lck and with the cytoskeletal protein paxillin through its COOH-terminal proline-rich domain. The tyrosine phosphorylation of RAFTK after T cell receptor-mediated stimulation was reduced by the pretreatment of cells with cytochalasin D, suggesting the role of the cytoskeleton in this process. These observations indicate that RAFTK participates in T cell receptor signaling and may act to link signals from the cell surface to the cytoskeleton and thereby affect the host immune response.

Comparison of Six Different Silicones In Vitro for Application as Glaucoma Drainage Device

PubMed Central

Windhövel, Claudia; Harder, Lisa; Bach, Jan-Peter; Teske, Michael; Grabow, Niels; Eickner, Thomas; Chichkov, Boris; Nolte, Ingo

2018-01-01

Silicones are widely used in medical applications. In ophthalmology, glaucoma drainage devices are utilized if conservative therapies are not applicable or have failed. Long-term success of these devices is limited by failure to control intraocular pressure due to fibrous encapsulation. Therefore, different medical approved silicones were tested in vitro for cell adhesion, cell proliferation and viability of human Sclera (hSF) and human Tenon fibroblasts (hTF). The silicones were analysed also depending on the sample preparation according to the manufacturer’s instructions. The surface quality was characterized with environmental scanning electron microscope (ESEM) and water contact angle measurements. All silicones showed homogeneous smooth and hydrophobic surfaces. Cell adhesion was significantly reduced on all silicones compared to the negative control. Proliferation index and cell viability were not influenced much. For development of a new glaucoma drainage device, the silicones Silbione LSR 4330 and Silbione LSR 4350, in this study, with low cell counts for hTF and low proliferation indices for hSF, and silicone Silastic MDX4-4210, with low cell counts for hSF and low proliferation indices for hTF, have shown the best results in vitro. Due to the high cell adhesion shown on Silicone LSR 40, 40,026, this material is unsuitable. PMID:29495462

Effect and possible mechanism of monocyte-derived VEGF on monocyte-endothelial cellular adhesion after electrical burns.

PubMed

Ruan, Qiongfang; Zhao, Chaoli; Ye, Ziqing; Ruan, Jingjing; Xie, Qionghui; Xie, Weiguo

2015-06-01

One of the major obstacles in the treatment of severe electrical burns is properly handling the resulting uncontrolled inflammation. Such inflammation often causes secondary injury and necrosis, thus complicating patient outcomes. Vascular endothelial grow factor (VEGF) has emerged as an important mediator for the recruitment of monocytes to the site inflammation. This study was designed to explore the effects and possible mechanism of VEGF on monocyte-endothelial cellular adhesion. To do so, we used a cultured human monocytic cell line (THP-1) that was stimulated with serum derived from rats that had received electrical burns. Serum was obtained from rats that had received electrical burns. Both the VEGF and soluble flt-1 (sflt-1) concentrations of the serum were determined by double-antibody sandwich ELISA. The concentrations of VEGF, sflt-1, and TNF-α obtained from the cell-free cultured supernatant of THP-1 cells that had been exposed to the serum were then determined by double-antibody sandwich ELISA. Serum-stimulated THP-1 cells were added to wells with a monolayer of endothelial cells to detect the level of monocyte-endothelial cells adhesion. Finally, the state of phosphorylation of AKT was determined by Western blotting. Both in vivo and in vitro studies showed that compared to controls, the levels of VEGF were significantly increased after electrical burns. This increased was accompanied by a reduction of sflt-1 levels. Furthermore, the serum of rats that had received electrical burns was able to both activate monocytes to secrete TNF-α and enhance monocyte-endothelial cell adhesion. Treatment with the serum also resulted in an up-regulation of the phosphorylation of AKT, but had no effect on the total levels of AKT. Phosphatidylinositide 3-kinases (PI3K) inhibition decreased the number of THP-1 cells that were adhered to endothelial cells. Finally, sequestering VEGF with sflt-1 was able to reduce the effect on monocyte-endothelial cells adhesion by blocking the PI3K signaling pathway. Our results indicate that VEGF is implicated in the pathogenesis of inflammation after electrical burns. Inhibition of VEGF activity could attenuate monocyte-endothelial cells adhesion by suppressing the state of phosphorylation of AKT, which is downstream of the PI3K signaling pathway. Copyright © 2014 Elsevier Ltd and ISBI. All rights reserved.

Multiple myeloma-related deregulation of bone marrow-derived CD34(+) hematopoietic stem and progenitor cells.

PubMed

Bruns, Ingmar; Cadeddu, Ron-Patrick; Brueckmann, Ines; Fröbel, Julia; Geyh, Stefanie; Büst, Sebastian; Fischer, Johannes C; Roels, Frederik; Wilk, Christian Matthias; Schildberg, Frank A; Hünerlitürkoglu, Ali-Nuri; Zilkens, Christoph; Jäger, Marcus; Steidl, Ulrich; Zohren, Fabian; Fenk, Roland; Kobbe, Guido; Brors, Benedict; Czibere, Akos; Schroeder, Thomas; Trumpp, Andreas; Haas, Rainer

2012-09-27

Multiple myeloma (MM) is a clonal plasma cell disorder frequently accompanied by hematopoietic impairment. We show that hematopoietic stem and progenitor cells (HSPCs), in particular megakaryocyte-erythrocyte progenitors, are diminished in the BM of MM patients. Genomic profiling of HSPC subsets revealed deregulations of signaling cascades, most notably TGFβ signaling, and pathways involved in cytoskeletal organization, migration, adhesion, and cell-cycle regulation in the patients. Functionally, proliferation, colony formation, and long-term self-renewal were impaired as a consequence of activated TGFβ signaling. In accordance, TGFβ levels in the BM extracellular fluid were elevated and mesenchymal stromal cells (MSCs) had a reduced capacity to support long-term hematopoiesis of HSPCs that completely recovered on blockade of TGFβ signaling. Furthermore, we found defective actin assembly and down-regulation of the adhesion receptor CD44 in MM HSPCs functionally reflected by impaired migration and adhesion. Still, transplantation into myeloma-free NOG mice revealed even enhanced engraftment and normal differentiation capacities of MM HSPCs, which underlines that functional impairment of HSPCs depends on MM-related microenvironmental cues and is reversible. Taken together, these data implicate that hematopoietic suppression in MM emerges from the HSPCs as a result of MM-related microenvironmental alterations.

The effect of Piper betle and Psidium guajava extracts on the cell-surface hydrophobicity of selected early settlers of dental plaque.

PubMed

Razak, Fathilah Abdul; Othman, Rofina Yasmin; Rahim, Zubaidah Haji Abd

2006-06-01

The adhesion of early settlers of dental plaque to the tooth surface has a role in the initiation of the development of dental plaque. The hydrophobic surface properties of the bacteria cell wall are indirectly responsible for the adhesion of the bacteria cell to the acquired pellicle on the tooth surfaces. In this study, the effect of aqueous extract of two plants (Psidium guajava and Piper betle) on the cell-surface hydro-phobicity of early settlers of dental plaque was determined in vitro. Hexadecane, a hydrocarbon was used to represent the hydrophobic surface of the teeth in the oral cavity. It was found that treatment of the early plaque settlers with 1 mg/ml extract of Psidium guajava reduced the cell-surface hydrophobicity of Strep. sanguinis, Strep. mitis and Actinomyces sp. by 54.1%, 49.9% and 40.6%, respectively. Treatment of these bacteria with the same concentration of Piper betle however, showed a comparatively lesser effect (< 10%). It was also observed that the anti-adhesive effect of the two extracts on the binding of the early plaque settlers to hexadecane is concentration dependent.

Adhesion mechanisms in embryogenesis and in cancer invasion and metastasis.

PubMed

Thiery, J P; Boyer, B; Tucker, G; Gavrilovic, J; Valles, A M

1988-01-01

Cell-substratum and cell-cell adhesion mechanisms contribute to the development of animal form. The adhesive status of embryonic cells has been analysed during epithelial-mesenchymal cell interconversion and in cell migrations. Clear-cut examples of the modulation of cell adhesion molecules (CAMs) have been described at critical periods of morphogenesis. In chick embryos the three primary CAMs (N-CAM. L-CAM and N-cadherin) present early in embryogenesis are expressed later in a defined pattern during morphogenesis and histogenesis. The axial mesoderm derived from gastrulating cells expresses increasing amounts of N-cadherin and N-CAM. During metamerization these two adhesion molecules become abundant at somitic cell surfaces. Both CAMs are functional in an in vitro aggregation assay; however, the calcium-dependent adhesion molecule N-cadherin is more sensitive to perturbation by specific antibodies. Neural crest cells which separate from the neural epithelium lose their primary CAMs in a defined time-sequence. Adhesion to fibronectins via specific surface receptors becomes a predominant interaction during the migratory process, while some primary and secondary CAMs are expressed de novo during the ontogeny of the peripheral nervous system. In vitro, different fibronectin functional domains have been identified in the attachment, spreading and migration of neural crest cells. The fibronectin receptors which transduce the adhesive signals play a key role in the control of cell movement. All these results have prompted us to examine whether similar mechanisms operate in carcinoma cell invasion and metastasis. In vitro, rat bladder transitional carcinoma cells convert reversibly into invasive mesenchymal cells. A rapid modulation of adhesive properties is found during the epithelial-mesenchymal carcinoma cell interconversion. The different model systems analysed demonstrate that a limited repertoire of adhesion molecules, expressed in a well-defined spatiotemporal pattern, is involved in tissue formation and in key processes of tumour spread.

Mechanical, In Vitro Antimicrobial and Biological Properties of Plasma Sprayed Silver-Doped Hydroxyapatite Coating

PubMed Central

Roy, Mangal; Fielding, Gary A.; Beyenal, Haluk; Bandyopadhyay, Amit; Bose, Susmita

2012-01-01

Implant related infection is one of the key concerns in total joint hip arthroplasties. In order to reduce bacterial adhesion, silver (Ag) / silver oxide (Ag2O) doping was used in plasma sprayed hydroxyapatite (HA) coating on titanium substrate. HA powder was doped with 2.0, 4.0 and 6.0 wt% Ag, heat treated at 800 °C and used for plasma spray coating using a 30 kW plasma spray system, equipped with supersonic nozzle. Application of supersonic plasma nozzle significantly reduced phase decomposition and amorphous phase formation in the HA coatings as evident by X-ray diffraction (XRD) study and Fourier transformed infrared spectroscopic (FTIR) analysis. Adhesive bond strength of more than 15 MPa ensured the mechanical integrity of the coatings. Resistance against bacterial adhesion of the coatings was determined by challenging them against Pseudomonas Aeruginosa (PAO1). Live/Dead staining of the adherent bacteria on the coating surfaces indicated a significant reduction in bacterial adhesion due to the presence of Ag. In vitro cell-material interactions and alkaline phosphatase (ALP) protein expressions were evaluated by culturing human fetal osteoblast cells (hFOB). Present results suggest that the plasma sprayed HA coatings doped with an optimum amount of Ag can have excellent antimicrobial property without altering mechanical property of the Ag doped HA coatings. PMID:22313742

Mechanical, in vitro antimicrobial, and biological properties of plasma-sprayed silver-doped hydroxyapatite coating.

PubMed

Roy, Mangal; Fielding, Gary A; Beyenal, Haluk; Bandyopadhyay, Amit; Bose, Susmita

2012-03-01

Implant-related infection is one of the key concerns in total joint hip arthroplasties. To reduce bacterial adhesion, we used silver (Ag)/silver oxide (Ag(2)O) doping in plasma sprayed hydroxyapatite (HA) coating on titanium substrate. HA powder was doped with 2.0, 4.0, and 6.0 wt % Ag, heat-treated at 800 °C and used for plasma spray coating using a 30 kW plasma spray system, equipped with supersonic nozzle. Application of supersonic plasma nozzle significantly reduced phase decomposition and amorphous phase formation in the HA coatings as evident by X-ray diffraction (XRD) study and Fourier transformed infrared spectroscopic (FTIR) analysis. Adhesive bond strength of more than 15 MPa ensured the mechanical integrity of the coatings. Resistance against bacterial adhesion of the coatings was determined by challenging them against Pseudomonas aeruginosa (PAO1). Live/dead staining of the adherent bacteria on the coating surfaces indicated a significant reduction in bacterial adhesion due to the presence of Ag. In vitro cell-material interactions and alkaline phosphatase (ALP) protein expressions were evaluated by culturing human fetal osteoblast cells (hFOB). Our results suggest that the plasma-sprayed HA coatings doped with an optimum amount of Ag can have excellent antimicrobial property without altering mechanical property of the Ag-doped HA coatings. © 2012 American Chemical Society

In vitro adhesion of fibroblastic cells to titanium alloy discs treated with sodium hydroxide.

PubMed

Al Mustafa, Maisa; Agis, Hermann; Müller, Heinz-Dieter; Watzek, Georg; Gruber, Reinhard

2015-01-01

Adhesion of osteogenic cells on titanium surfaces is a prerequisite for osseointegration. Alkali treatment can increase the hydrophilicity of titanium implant surfaces, thereby supporting the adhesion of blood components. However, it is unclear if alkali treatment also supports the adhesion of cells with a fibroblastic morphology to titanium. Here, we have used a titanium alloy (Ti-6AL-4V) processed by alkali treatment to demonstrate the impact of hydrophilicity on the adhesion of primary human gingival fibroblast and bone cells. Also included were the osteosarcoma and fibroblastoma cell lines, MG63 and L929, respectively. Cell adhesion was determined by scanning electron microscopy. We also measured viability, proliferation, and protein synthesis of the adherent cells. Alkali treatment increased the adhesion of gingival fibroblasts, bone cells, and the two cell lines when seeded onto the titanium alloy surface for 1 h. At 3 h, no significant changes in cell adhesion were observed. Cells grown for 1 day on the titanium alloy surfaces processed by alkali treatment behave similarly to untreated controls with regard to viability, proliferation, and protein synthesis. Based on these preliminary In vitro findings, we conclude that alkali treatment can support the early adhesion of cells with fibroblastic characteristics to a titanium alloy surface. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

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

The design of superhydrophobic stainless steel surfaces by controlling nanostructures: A key parameter to reduce the implantation of pathogenic bacteria.

PubMed

Bruzaud, Jérôme; Tarrade, Jeanne; Celia, Elena; Darmanin, Thierry; Taffin de Givenchy, Elisabeth; Guittard, Frédéric; Herry, Jean-Marie; Guilbaud, Morgan; Bellon-Fontaine, Marie-Noëlle

2017-04-01

Reducing bacterial adhesion on substrates is fundamental for various industries. In this work, new superhydrophobic surfaces are created by electrodeposition of hydrophobic polymers (PEDOT-F 4 or PEDOT-H 8 ) on stainless steel with controlled topographical features, especially at a nano-scale. Results show that anti-bioadhesive and anti-biofilm properties require the control of the surface topographical features, and should be associated with a low adhesion of water onto the surface (Cassie-Baxter state) with limited crevice features at the scale of bacterial cells (nano-scale structures). Copyright © 2016. Published by Elsevier B.V.

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

PubMed

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

2006-07-01

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

RGD Surface Functionalization of the Hydrophilic Acrylic Intraocular Lens Material to Control Posterior Capsular Opacification

PubMed Central

Huang, Yi-Shiang; Bertrand, Virginie; Bozukova, Dimitriya; Pagnoulle, Christophe; Labrugère, Christine; De Pauw, Edwin; De Pauw-Gillet, Marie-Claire; Durrieu, Marie-Christine

2014-01-01

Posterior Capsular Opacification (PCO) is the capsule fibrosis developed on implanted IntraOcular Lens (IOL) by the de-differentiation of Lens Epithelial Cells (LECs) undergoing Epithelial Mesenchymal Transition (EMT). Literature has shown that the incidence of PCO is multifactorial including the patient's age or disease, surgical technique, and IOL design and material. Reports comparing hydrophilic and hydrophobic acrylic IOLs have shown that the former has more severe PCO. On the other hand, we have previously demonstrated that the adhesion of LECs is favored on hydrophobic compared to hydrophilic materials. By combining these two facts and contemporary knowledge in PCO development via the EMT pathway, we propose a biomimetically inspired strategy to promote LEC adhesion without de-differentiation to reduce the risk of PCO development. By surface grafting of a cell adhesion molecule (RGD peptide) onto the conventional hydrophilic acrylic IOL material, the surface-functionalized IOL can be used to reconstitute a capsule-LEC-IOL sandwich structure, which has been considered to prevent PCO formation in literature. Our results show that the innovative biomaterial improves LEC adhesion, while also exhibiting similar optical (light transmittance, optical bench) and mechanical (haptic compression force, IOL injection force) properties compared to the starting material. In addition, compared to the hydrophobic IOL material, our bioactive biomaterial exhibits similar abilities in LEC adhesion, morphology maintenance, and EMT biomarker expression, which is the crucial pathway to induce PCO. The in vitro assays suggest that this biomaterial has the potential to reduce the risk factor of PCO development. PMID:25501012

RGD surface functionalization of the hydrophilic acrylic intraocular lens material to control posterior capsular opacification.

PubMed

Huang, Yi-Shiang; Bertrand, Virginie; Bozukova, Dimitriya; Pagnoulle, Christophe; Labrugère, Christine; De Pauw, Edwin; De Pauw-Gillet, Marie-Claire; Durrieu, Marie-Christine

2014-01-01

Posterior Capsular Opacification (PCO) is the capsule fibrosis developed on implanted IntraOcular Lens (IOL) by the de-differentiation of Lens Epithelial Cells (LECs) undergoing Epithelial Mesenchymal Transition (EMT). Literature has shown that the incidence of PCO is multifactorial including the patient's age or disease, surgical technique, and IOL design and material. Reports comparing hydrophilic and hydrophobic acrylic IOLs have shown that the former has more severe PCO. On the other hand, we have previously demonstrated that the adhesion of LECs is favored on hydrophobic compared to hydrophilic materials. By combining these two facts and contemporary knowledge in PCO development via the EMT pathway, we propose a biomimetically inspired strategy to promote LEC adhesion without de-differentiation to reduce the risk of PCO development. By surface grafting of a cell adhesion molecule (RGD peptide) onto the conventional hydrophilic acrylic IOL material, the surface-functionalized IOL can be used to reconstitute a capsule-LEC-IOL sandwich structure, which has been considered to prevent PCO formation in literature. Our results show that the innovative biomaterial improves LEC adhesion, while also exhibiting similar optical (light transmittance, optical bench) and mechanical (haptic compression force, IOL injection force) properties compared to the starting material. In addition, compared to the hydrophobic IOL material, our bioactive biomaterial exhibits similar abilities in LEC adhesion, morphology maintenance, and EMT biomarker expression, which is the crucial pathway to induce PCO. The in vitro assays suggest that this biomaterial has the potential to reduce the risk factor of PCO development.

Down-regulation of CD19 expression inhibits proliferation, adhesion, migration and invasion and promotes apoptosis and the efficacy of chemotherapeutic agents and imatinib in SUP-B15 cells.

PubMed

Wu, Junqing; Liang, Bin; Qian, Yan; Tang, Liyuan; Xing, Chongyun; Zhuang, Qiang; Shen, Zhijian; Jiang, Songfu; Yu, Kang; Feng, Jianhua

2018-05-29

The survival rate of childhood acute lymphoblastic leukemia (ALL) has increased while that of Philadelphia-positive (Ph+) ALL remains low. CD19 is a B-cell specific molecule related to the survival and proliferation of normal B cells. However, there is little information available on the effects of CD19 on the biological behavior of Ph+ ALL cells. In this study, we explored a lentiviral vector-mediated short hairpin RNA (shRNA) expression vector to stably reduce CD19 expression in Ph+ ALL cell line SUP-B15 cells and investigated the effects of CD19 downregulation on cell proliferation, apoptosis, drug sensitivity, cell adhesion, cell migration and cell invasion in vitro. CD19 mRNA and protein expression levels were inhibited significantly by CD19 shRNA. Down-regulation of CD19 could inhibit cell proliferation, adhesion, migration and invasion, and increase cell apoptosis and the efficacy of chemotherapeutic agents and imatinib in SUP-B15 cells. Moreover, we found that down-regulation of CD19 expression inhibits cell proliferation and induces apoptosis in SUP-B15 cells in a p53-dependent manner. Taken together, our results suggest that lentiviral vector-mediated RNA interference of CD19 gene may be a promising strategy in the treatment of Ph+ ALL. This article is protected by copyright. All rights reserved.

Synergistic effect of two cell recognition systems: glycosphingolipid-glycosphingolipid interaction and integrin receptor interaction with pericellular matrix protein.

PubMed

Kojima, N; Hakomori, S

1991-12-01

GM3-expressing cells adhere, spread and migrate on plastic plates coated with Gg3, LacCer and Gb4, but not with other glycosphingolipids (GSLs). Thus, cell adhesion, spreading and migration through GSL-GSL interaction occur in an analogous fashion to the interaction of cells with adhesive matrix proteins [AP, e.g. fibronectin (FN), laminin (LN)] through their integrin receptors. In this study, the adhesion of two GM3-expressing cell lines (B16 melanoma and HEL299 fibroblast) on plastic plates co-coated with GSL plus AP is compared with adhesion on plates coated with GSL (Gg3 or LacCer) alone, or coated with AP alone. Results show that: (i) cell adhesion on GSL-coated plates takes place earlier in the incubation period than that on AP-coated plates; (ii) cell adhesion, as well as spreading, was greatly enhanced (in terms of strength and rapidity) on plates co-coated with GSL plus AP; (iii) repulsion (negative adhesion) of cells was observed on plates co-coated with AP plus N-acetyl-GM3 (NAcGM3) and was presumably based on repulsive NAcGM3-NAcGM3 interaction; (iv) GM3-dependent cell adhesion on GSL-coated plates, as well as synergistic promotion of cell adhesion (based on the GSL-GSL and AP-integrin systems), was suppressed by incubation of cells with anti-GM3 monoclonal antibody DH2 or sialidase. Synergistic adhesion of cells on GSL/AP co-coated plates was less inhibited by incubation with peptide sequences RGDS or YIGSR than was adhesion on plates coated with AP alone.(ABSTRACT TRUNCATED AT 250 WORDS)

In vivo studies of sickle red blood cells.

PubMed

Kaul, Dhananjay K; Fabry, Mary E

2004-03-01

The defining clinical feature of sickle cell anemia is periodic occurrence of painful vasoocclusive crisis. Factors that promote trapping and sickling of red cells in the microcirculation are likely to trigger vasoocclusion. The marked red cell heterogeneity in sickle blood and abnormal adhesion of sickle red cells to vascular endothelium would be major disruptive influences. Using ex vivo and in vivo models, the authors show how to dissect the relative contribution of heterogeneous sickle red cell classes to adhesive and obstructive events. These studies revealed that (1) both rheological abnormalities and adhesion of sickle red cells contribute to their abnormal hemodynamic behavior, (2) venules are the sites of sickle cell adhesion, and (3) sickle red cell deformability plays an important role in adhesive and obstructive events. Preferential adhesion of deformable sickle red cells in postcapillary venules followed by selective trapping of dense sickle red cells could result in vasoocclusion. An updated version of this 2-step model is presented. The multifactorial nature of sickle red cell adhesion needs to be considered in designing antiadhesive therapy in vivo.

The dipeptidyl peptidase-4 inhibitor Saxagliptin improves function of circulating pro-angiogenic cells from type 2 diabetic patients

PubMed Central

2014-01-01

Background Type 2 diabetes (T2D) is associated with reduction and dysfunction of circulating pro-angiogenic cells (PACs). DPP-4 inhibitors, a class of oral agents for T2D, might possess pleiotropic vasculoprotective activities. Herein, we tested whether DPP-4 inhibition with Saxagliptin affects the function of circulating PACs from T2D and healthy subjects. Methods PACs were isolated from T2D (n = 20) and healthy (n = 20) subjects. Gene expression, clonogenesis, proliferation, adhesion, migration and tubulisation were assessed in vitro by incubating PACs with or without Saxagliptin and SDF-1α. Stimulation of angiogenesis by circulating cells from T2D patients treated with Saxagliptin or other non-incretinergic drugs was assessed in vivo using animal models. Results Soluble DPP-4 activity was predominant over cellular activity and was successfully inhibited by Saxagliptin. At baseline, T2D compared to healthy PACs contained less acLDL+Lectin+ cells, and showed altered expression of genes related to adhesion and cell cycle regulation. This was reflected by impaired adhesion and clonogenesis/proliferative response of T2D PACs. Saxagliptin + SDF-1α improved adhesion and tube sustaining capacity of PACs from T2D patients. CD14+ PACs were more responsive to Saxagliptin than CD14- PACs. While Saxagliptin modestly reduced angiogenesis by mature endothelial cells, circulating PACs-progeny cells from T2D patients on Saxagliptin treatment displayed higher growth factor-inducible in vivo angiogenetic activity, compared to cells from T2D patients on non-incretinergic regimen. Conclusions Saxagliptin reverses PACs dysfunction associated with T2D in vitro and improves inducible angiogenesis by circulating cells in vivo. These data add knowledge to the potential pleiotropic cardiovascular effects of DPP-4 inhibition. PMID:24886621

The dipeptidyl peptidase-4 inhibitor saxagliptin improves function of circulating pro-angiogenic cells from type 2 diabetic patients.

PubMed

Poncina, Nicol; Albiero, Mattia; Menegazzo, Lisa; Cappellari, Roberta; Avogaro, Angelo; Fadini, Gian Paolo

2014-05-14

Type 2 diabetes (T2D) is associated with reduction and dysfunction of circulating pro-angiogenic cells (PACs). DPP-4 inhibitors, a class of oral agents for T2D, might possess pleiotropic vasculoprotective activities. Herein, we tested whether DPP-4 inhibition with Saxagliptin affects the function of circulating PACs from T2D and healthy subjects. PACs were isolated from T2D (n = 20) and healthy (n = 20) subjects. Gene expression, clonogenesis, proliferation, adhesion, migration and tubulisation were assessed in vitro by incubating PACs with or without Saxagliptin and SDF-1α. Stimulation of angiogenesis by circulating cells from T2D patients treated with Saxagliptin or other non-incretinergic drugs was assessed in vivo using animal models. Soluble DPP-4 activity was predominant over cellular activity and was successfully inhibited by Saxagliptin. At baseline, T2D compared to healthy PACs contained less acLDL(+)Lectin(+) cells, and showed altered expression of genes related to adhesion and cell cycle regulation. This was reflected by impaired adhesion and clonogenesis/proliferative response of T2D PACs. Saxagliptin + SDF-1α improved adhesion and tube sustaining capacity of PACs from T2D patients. CD14+ PACs were more responsive to Saxagliptin than CD14- PACs. While Saxagliptin modestly reduced angiogenesis by mature endothelial cells, circulating PACs-progeny cells from T2D patients on Saxagliptin treatment displayed higher growth factor-inducible in vivo angiogenetic activity, compared to cells from T2D patients on non-incretinergic regimen. Saxagliptin reverses PACs dysfunction associated with T2D in vitro and improves inducible angiogenesis by circulating cells in vivo. These data add knowledge to the potential pleiotropic cardiovascular effects of DPP-4 inhibition.

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

PubMed

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

2016-09-15

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

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.

Mastic Oil Inhibits the Metastatic Phenotype of Mouse Lung Adenocarcinoma Cells

PubMed Central

Loutrari, Heleni; Magkouta, Sophia; Papapetropoulos, Andreas; Roussos, Charis

2011-01-01

Mastic oil from Pistacia lentiscus variation chia, a natural combination of bioactive terpenes, has been shown to exert anti-tumor growth effects against a broad spectrum of cancers including mouse Lewis lung adenocarcinomas (LLC). However, no studies have addressed its anti-metastatic actions. In this study, we showed that treatment of LLC cells with mastic oil within a range of non-toxic concentrations (0.01–0.04% v/v): (a) abrogated their Matrigel invasion and migration capabilities in transwell assays; (b) reduced the levels of secreted MMP-2; (c) restricted phorbol ester-induced actin remodeling and (d) limited the length of neo-vessel networks in tumor microenvironment in the model of chick embryo chorioallantoic membrane. Moreover, exposure of LLC and endothelial cells to mastic oil impaired their adhesive interactions in a co-culture assay and reduced the expression of key adhesion molecules by endothelial cells upon their stimulation with tumor necrosis factor-alpha. Overall, this study provides novel evidence supporting a multipotent role for mastic oil in prevention of crucial processes related to cancer metastasis. PMID:24212641

Effects of magnolol and honokiol on adhesion, yeast-hyphal transition, and formation of biofilm by Candida albicans.

PubMed

Sun, Lingmei; Liao, Kai; Wang, Dayong

2015-01-01

The first step in infection by Candida albicans is adhesion to host cells or implanted medical devices and this followed by hyphal growth and biofilm formation. Yeast-to-hyphal transition has long been identified as a key factor in fungal virulence. Following biofilm formation, C. albicans is usually less sensitive or insensitive to antifungals. Therefore, development of new antifungals with inhibitory action on adhesion, yeast-hyphal transition and biofilm formation by C. albicans is very necessary. The effects of magnolol and honokiol on hypha growth were investigated using different induction media. Their inhibitory effects were determined using the 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5- carboxanilide assay, and biofilm thickness and viability were observed by a confocal scanning laser microscope. Mammalian cells were used in adhesion assays. Genes related to hyphae development and cell adhesions were analyzed by real-time reverse transcription-polymerase chain reaction. The exogenous cyclic adenosine monophosphate was used to determine the mechanisms of action of magnolol and honokiol. Caenorhabditis elegans was used as an in vivo model to estimate the antifungal activities of magnolol and honokiol. Magnolol and honokiol inhibited adhesion, the transition from yeast to hypha, and biofilm formation by C. albicans through the Ras1-cAMP-Efg1 pathway. Moreover, magnolol and honokiol prolonged the survival of nematodes infected by C. albicans. Magnolol and honokiol have potential inhibitory effects against biofilm formation by C. albicans. This study provides useful information towards the development of new strategies to reduce the incidence of C. albicans biofilm-associated infection.

Redistribution of Adhesive Forces through Src/FAK Drives Contact Inhibition of Locomotion in Neural Crest.

PubMed

Roycroft, Alice; Szabó, András; Bahm, Isabel; Daly, Liam; Charras, Guillaume; Parsons, Maddy; Mayor, Roberto

2018-06-04

Contact inhibition of locomotion is defined as the behavior of cells to cease migrating in their former direction after colliding with another cell. It has been implicated in multiple developmental processes and its absence has been linked to cancer invasion. Cellular forces are thought to govern this process; however, the exact role of traction through cell-matrix adhesions and tension through cell-cell adhesions during contact inhibition of locomotion remains unknown. Here we use neural crest cells to address this and show that cell-matrix adhesions are rapidly disassembled at the contact between two cells upon collision. This disassembly is dependent upon the formation of N-cadherin-based cell-cell adhesions and driven by Src and FAK activity. We demonstrate that the loss of cell-matrix adhesions near the contact leads to a buildup of tension across the cell-cell contact, a step that is essential to drive cell-cell separation after collision. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Octasaccharide is the minimal length unit required for efficient binding of cyclophilin B to heparin and cell surface heparan sulphate.

PubMed

Vanpouille, Christophe; Denys, Agnès; Carpentier, Mathieu; Pakula, Rachel; Mazurier, Joël; Allain, Fabrice

2004-09-01

Cyclophilin B (CyPB) is a heparin-binding protein first identified as a receptor for cyclosporin A. In previous studies, we reported that CyPB triggers chemotaxis and integrin-mediated adhesion of T-lymphocytes by way of interaction with two types of binding sites. The first site corresponds to a signalling receptor; the second site has been identified as heparan sulphate (HS) and appears crucial to induce cell adhesion. Characterization of the HS-binding unit is critical to understand the requirement of HS in pro-adhesive activity of CyPB. By using a strategy based on gel mobility shift assays with fluorophore-labelled oligosaccharides, we demonstrated that the minimal heparin unit required for efficient binding of CyPB is an octasaccharide. The mutants CyPB(KKK-) [where KKK- refers to the substitutions K3A(Lys3-->Ala)/K4A/K5A] and CyPB(DeltaYFD) (where Tyr14-Phe-Asp16 has been deleted) failed to interact with octasaccharides, confirming that the Y14FD16 and K3KK5 clusters are required for CyPB binding. Molecular modelling revealed that both clusters are spatially arranged so that they may act synergistically to form a binding site for the octasaccharide. We then demonstrated that heparin-derived octasaccharides and higher degree of polymerization oligosaccharides inhibited the interaction between CyPB and fluorophore-labelled HS chains purified from T-lymphocytes, and strongly reduced the HS-dependent pro-adhesive activity of CyPB. However, oligosaccharides or heparin were unable to restore adhesion of heparinase-treated T-lymphocytes, indicating that HS has to be present on the cell membrane to support the pro-adhesive activity of CyPB. Altogether, these results demonstrate that the octasaccharide is likely to be the minimal length unit required for efficient binding of CyPB to cell surface HS and consequent HS-dependent cell responses.

Octasaccharide is the minimal length unit required for efficient binding of cyclophilin B to heparin and cell surface heparan sulphate

PubMed Central

2004-01-01

Cyclophilin B (CyPB) is a heparin-binding protein first identified as a receptor for cyclosporin A. In previous studies, we reported that CyPB triggers chemotaxis and integrin-mediated adhesion of T-lymphocytes by way of interaction with two types of binding sites. The first site corresponds to a signalling receptor; the second site has been identified as heparan sulphate (HS) and appears crucial to induce cell adhesion. Characterization of the HS-binding unit is critical to understand the requirement of HS in pro-adhesive activity of CyPB. By using a strategy based on gel mobility shift assays with fluorophore-labelled oligosaccharides, we demonstrated that the minimal heparin unit required for efficient binding of CyPB is an octasaccharide. The mutants CyPBKKK− [where KKK− refers to the substitutions K3A(Lys3→Ala)/K4A/K5A] and CyPBΔYFD (where Tyr14-Phe-Asp16 has been deleted) failed to interact with octasaccharides, confirming that the Y14FD16 and K3KK5 clusters are required for CyPB binding. Molecular modelling revealed that both clusters are spatially arranged so that they may act synergistically to form a binding site for the octasaccharide. We then demonstrated that heparin-derived octasaccharides and higher degree of polymerization oligosaccharides inhibited the interaction between CyPB and fluorophore-labelled HS chains purified from T-lymphocytes, and strongly reduced the HS-dependent pro-adhesive activity of CyPB. However, oligosaccharides or heparin were unable to restore adhesion of heparinase-treated T-lymphocytes, indicating that HS has to be present on the cell membrane to support the pro-adhesive activity of CyPB. Altogether, these results demonstrate that the octasaccharide is likely to be the minimal length unit required for efficient binding of CyPB to cell surface HS and consequent HS-dependent cell responses. PMID:15109301

Tuning cell adhesive properties via layer-by-layer assembly of chitosan and alginate

PubMed Central

Silva, Joana M.; García, José R.; Reis, Rui L.; García, Andrés J.; Mano, João F.

2017-01-01

Understanding the mechanisms controlling cell-multilayer film interactions is crucial to the successful engineering of these coatings for biotechnological and biomedical applications. Herein, we present a strategy to tune the cell adhesive properties of multilayers based on marine polysaccharides with and without cross-linking and/or coating with extracellular matrix proteins. Chemical cross-linking of multilayers improved mechanical properties of the coatings but also elicited changes in surface chemistry that alter the adhesion of human umbilical vein endothelial cells. We evaluated a strategy to decouple the mechanical and chemical properties of these films, enabling the transition from cell-adhesive to cell-resistant multilayers. Addition of chitosan/alginate multilayers on top of cross-linked films decreased endothelial cell adhesion, spreading, and proliferation to similar levels as uncross-linked films. Our findings highlight the key role of surface chemistry in cell-multilayer film interactions, and these engineered nanocoatings represent a tunable model of cell adhesive and non-adhesive multilayered films. PMID:28126597

Molecular analysis of antigen-independent adhesion forces between T and B lymphocytes.

PubMed Central

Amblard, F; Auffray, C; Sekaly, R; Fischer, A

1994-01-01

The low-affinity interactions underlying antigen recognition by T-cell receptors (TCRs) are thought to involve antigen-independent adhesion mechanisms. Using a hydrodynamic approach, we found that antigen-independent adhesion occurred between human B cells and resting T cells in a transient and temperature-dependent fashion. The mean cell-cell adhesion force was 0.32 x 10(-9) N and was generated by similar contributions (0.16 x 10(-9) N) of the LFA-1- and CD2-dependent adhesion pathways. After T-cell stimulation with a phorbol ester, the force contributed by LFA-1 was drastically increased, while that of CD2 was unaffected. We propose that weak receptor-mediated adhesion initiates antigen-independent intercellular contacts required for antigen recognition by the TCR and is upregulated following TCR engagement. The method used permits adhesion forces between living cells to be resolved at the molecular level and should prove valuable for the rapid assessment of interaction forces between various types of cells and cell-sized particles. Images PMID:7909604

Cell-cell adhesion in the cnidaria: insights into the evolution of tissue morphogenesis.

PubMed

Magie, Craig R; Martindale, Mark Q

2008-06-01

Cell adhesion is a major aspect of cell biology and one of the fundamental processes involved in the development of a multicellular animal. Adhesive mechanisms, both cell-cell and between cell and extracellular matrix, are intimately involved in assembling cells into the three-dimensional structures of tissues and organs. The modulation of adhesive complexes could therefore be seen as a central component in the molecular control of morphogenesis, translating information encoded within the genome into organismal form. The availability of whole genomes from early-branching metazoa such as cnidarians is providing important insights into the evolution of adhesive processes by allowing for the easy identification of the genes involved in adhesion in these organisms. Discovery of the molecular nature of cell adhesion in the early-branching groups, coupled with comparisons across the metazoa, is revealing the ways evolution has tinkered with this vital cellular process in the generation of the myriad forms seen across the animal kingdom.

Flaxseed and cardiovascular health.

PubMed

Prasad, Kailash

2009-11-01

Flaxseed and its components may improve cardiovascular health because of their numerous attributes. Flaxseed contains 35% of its mass as oil, of which 55% is alpha-linolenic acid (ALA). Flax meal, which is devoid of oil, contains the lignan secoisolariciresinol diglucoside (SDG). Flaxseed, flaxseed with very low ALA, flaxseed oil, flax lignan complex (FLC), and SDG reduce the development of hypercholesterolemic atherosclerosis by 46%, 69%, 0%, 73%, and 34%, respectively, in the rabbit model. FLC and SDG slow the progression of atherosclerosis but have no effect in regression of atherosclerosis. Suppression of atherosclerosis by flaxseed is the result of its lignan content and not the result of ALA content. Suppression of atherosclerosis is associated with lowering of serum lipids and antioxidant activity. Effects of flaxseed on serum lipids in experimental animals are variable from no change to slight reduction. Flaxseed oil does not affect serum lipids, except for a slight reduction in serum triglycerides. Lignan in general reduces serum total cholesterol and low-density lipoprotein cholesterol and raises serum high-density lipoprotein cholesterol. SDG and its metabolites have antioxidant activity. Flaxseed and flaxseed oil do not have antioxidant activity except they suppress oxygen radical production by white blood cells. Flaxseed oil/ALA has variable effects on inflammatory mediators/markers (interleukin [IL]-1beta, IL-2, IL-4, IL-6, IL-10, tumor necrosis factor-alpha, interferon-gamma, C-reactive protein, and serum amyloid A). Doses of ALA less than 14 g/d do not affect inflammatory mediators/markers, but 14 g/d or greater reduce inflammatory mediators/markers. Flaxseed oil decreases soluble vascular cell adhesion molecule-1 but has no effect on soluble intracellular adhesion molecule-1, soluble E-selectin, and monocyte colony-stimulating factor. Flaxseed has variable effects on IL-6, high-sensitivity C-reactive protein, and soluble vascular cell adhesion molecule-1. FLC reduces plasma levels of C-reactive protein but has no effects on IL-6, tumor necrosis factor-alpha, soluble intracellular adhesion molecule-1, soluble vascular cell adhesion molecule-1, or monocyte chemoattractant protein. Flaxseed has a very small hypotensive effect, but flaxseed oil does not lower blood pressure. However, SDG is a very potent hypotensive agent. Flaxseed oil decreases platelet aggregation and increases platelet activating inhibitor-1 and bleeding time. Flaxseed and FLC have no effect on the hemopoietic system. SDG is a potent angiogenic and antiapoptotic agent that may have a role in cardioprotection in ischemic heart disease. In conclusion, flaxseed, FLC, and SDG, but not flaxseed oil, suppress atherosclerosis, and FLC and SDG slow progression of atherosclerosis but have no effect on regression. Flaxseed oil suppresses oxygen radical production by white blood cells, prolongs bleeding time, and in higher doses suppresses serum levels of inflammatory mediators and does not lower serum lipids.

Identification of a Monocyte Receptor on Herpesvirus-Infected Endothelial Cells

NASA Astrophysics Data System (ADS)

Etingin, Orli R.; Silverstein, Roy L.; Hajjar, David P.

1991-08-01

The adhesion of circulating blood cells to vascular endothelium may be an initial step in atherosclerosis, inflammation, and wound healing. One mechanism for promoting cell-cell adhesion involves the expression of adhesion molecules on the surface of the target cell. Herpes simplex virus infection of endothelium induces arterial injury and has been implicated in the development of human atherosclerosis. We now demonstrate that HSV-infected endothelial cells express the adhesion molecule GMP140 and that this requires cell surface expression of HSV glycoprotein C and local thrombin generation. Monocyte adhesion to HSV-infected endothelial cells was completely inhibited by anti-GMP140 antibodies but not by antibodies to other adhesion molecules such as VCAM and ELAM-1. The induction of GMP140 expression on HSV-infected endothelium may be an important pathophysiological mechanism in virus-induced cell injury and inflammation.

Cadherin-23 Mediates Heterotypic Cell-Cell Adhesion between Breast Cancer Epithelial Cells and Fibroblasts

PubMed Central

Apostolopoulou, Maria; Ligon, Lee

2012-01-01

In the early stages of breast cancer metastasis, epithelial cells penetrate the basement membrane and invade the surrounding stroma, where they encounter fibroblasts. Paracrine signaling between fibroblasts and epithelial tumor cells contributes to the metastatic cascade, but little is known about the role of adhesive contacts between these two cell types in metastasis. Here we show that MCF-7 breast cancer epithelial cells and normal breast fibroblasts form heterotypic adhesions when grown together in co-culture, as evidenced by adhesion assays. PCR and immunoblotting show that both cell types express multiple members of the cadherin superfamily, including the atypical cadherin, cadherin-23, when grown in isolation and in co-culture. Immunocytochemistry experiments show that cadherin-23 localizes to homotypic adhesions between MCF-7 cells and also to heterotypic adhesions between the epithelial cells and fibroblasts, and antibody inhibition and RNAi experiments show that cadherin-23 plays a role in mediating these adhesive interactions. Finally, we show that cadherin-23 is upregulated in breast cancer tissue samples, and we hypothesize that heterotypic adhesions mediated by this atypical cadherin may play a role in the early stages of metastasis. PMID:22413011

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

PubMed

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

2012-01-01

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

Cell adhesion molecules, the extracellular matrix and oral squamous carcinoma.

PubMed

Lyons, A J; Jones, J

2007-08-01

Carcinomas are characterized by invasion of malignant cells into the underlying connective tissue and migration of malignant cells to form metastases at distant sites. These processes require alterations in cell-cell and cell-extracellular matrix interactions. As cell adhesion molecules play a role in cell-cell and cell-extracellular matrix adhesion and interactions they are involved in the process of tumour invasion and metastases. In epithelial tissues, receptors of the integrin family mediate adhesion to the adjacent matrix whereas cadherins largely mediate intercellular adhesion. These and other cell adhesion molecules such as intercellular adhesion molecule-1, CD44, dystroglycans and selectins, are involved and undergo changes in carcinomas, which provide possible targets for anti-cancer drug treatments. In the extracellular matrix that is associated with tumours, laminin 5, oncofetal fibronectin and tenascin C appear. The degree of expression of some of these moieties indicates prognosis in oral cancer and offer targets for antibody-directed radiotherapy. Metalloproteases which degrade the extracellular matrix are increased in carcinomas, and their activity is necessary for tumour angiogenesis and consequent invasion and metastases. Metalloprotease inhibitors have begun to produce decreases in mortality in clinical trials. This report provides a brief overview of our current understanding of cell adhesion molecules, the extracellular matrix, tumour invasion and metastasis.

Characterization of the gene encoding pinin/DRS/memA and evidence for its potential tumor suppressor function.

PubMed

Shi, Y; Ouyang, P; Sugrue, S P

2000-01-13

Several cell adhesion-related proteins have been shown to act as tumor-suppressors (TS) in the neoplastic progression of epithelial-derived tumors. Pinin/DRS/memA was first identified in our laboratory and it was shown to be a cell adhesion-related molecule. Our previous study demonstrated that restoration of pinin expression in transformed cells not only positively influenced cellular adhesive properties but also reversed the transformed phenotype to more epithelial-like. Here, we show by FISH analysis that the gene locus for pinin is within 14q13. The alignment of the pinin gene with STS markers localized the gene to the previously identified TS locus D14S75-D14S288. Northern analyses revealed diminished pinin mRNA in renal cell carcinomas (RCC) and certain cancer cell lines. Immunohistochemical examination of tumor samples demonstrated absent or greatly reduced pinin in transitional cell carcinoma (TCC) and RCC tumors. TCC-derived J82 cells as well as EcR-293 cells transfected with full-length pinin cDNA demonstrated inhibition of anchorage-independent growth of cells in soft agar. Furthermore, methylation analyses revealed that aberrant methylation of pinin CpG islands was correlated with decreased/absent pinin expression in a subset of tumor tissues. These data lend significant support to the hypothesis that pinin/DRS/memA may act as a tumor suppressor in certain types of cancers.

Laminin-411 Is a Vascular Ligand for MCAM and Facilitates TH17 Cell Entry into the CNS

PubMed Central

Flanagan, Ken; Fitzgerald, Kent; Baker, Jeanne; Regnstrom, Karin; Gardai, Shyra; Bard, Frederique; Mocci, Simonetta; Seto, Pui; You, Monica; Larochelle, Catherine; Prat, Alexandre; Chow, Samuel; Li, Lauri; Vandevert, Chris; Zago, Wagner; Lorenzana, Carlos; Nishioka, Christopher; Hoffman, Jennifer; Botelho, Raquel; Willits, Christopher; Tanaka, Kevin; Johnston, Jennifer; Yednock, Ted

2012-01-01

TH17 cells enter tissues to facilitate pathogenic autoimmune responses, including multiple sclerosis (MS). However, the adhesion molecules involved in the unique migratory capacity of TH17 cells, into both inflamed and uninflamed tissues remain unclear. Herein, we characterize MCAM (CD146) as an adhesion molecule that defines human TH17 cells in the circulation; following in vitro restimulation of human memory T cells, nearly all of the capacity to secrete IL-17 is contained within the population of cells expressing MCAM. Furthermore, we identify the MCAM ligand as laminin 411, an isoform of laminin expressed within the vascular endothelial basement membranes under inflammatory as well as homeotstatic conditions. Purified MCAM-Fc binds to laminin 411 with an affinity of 27 nM, and recognizes vascular basement membranes in mouse and human tissue. MCAM-Fc binding was undetectable in tissue from mice with targeted deletion of laminin 411, indicating that laminin 411 is a major tissue ligand for MCAM. An anti-MCAM monoclonal antibody, selected for inhibition of laminin binding, as well as soluble MCAM-Fc, inhibited T cell adhesion to laminin 411 in vitro. When administered in vivo, the antibody reduced TH17 cell infiltration into the CNS and ameliorated disease in an animal model of MS. Our data suggest that MCAM and laminin 411 interact to facilitate TH17 cell entry into tissues and promote inflammation. PMID:22792325

Application of Organosilane Monolayer Template to Quantitative Evaluation of Cancer Cell Adhesive Ability

NASA Astrophysics Data System (ADS)

Tanii, Takashi; Sasaki, Kosuke; Ichisawa, Kota; Demura, Takanori; Beppu, Yuichi; Vu, Hoan Anh; Thanh Chi, Hoan; Yamamoto, Hideaki; Sato, Yuko

2011-06-01

The adhesive ability of two human pancreatic cancer cell lines was evaluated using organosilane monolayer templates (OMTs). Using the OMT, the spreading area of adhered cells can be limited, and this enables us to focus on the initial attachment process of adhesion. Moreover, it becomes possible to arrange the cells in an array and to quantitatively evaluate the number of attached cells. The adhesive ability of the cancer cells cultured on the OMT was controlled by adding (-)-epigallocatechin-3-gallate (EGCG), which blocks a receptor that mediates cell adhesion and is overexpressed in cancer cells. Measurement of the relative ability of the cancer cells to attach to the OMT revealed that the ability for attachment decreased with increasing EGCG concentration. The results agreed well with the western blot analysis, indicating that the OMT can potentially be employed to evaluate the adhesive ability of various cancer cells.

Modeling keratinocyte wound healing dynamics: Cell-cell adhesion promotes sustained collective migration.

PubMed

Nardini, John T; Chapnick, Douglas A; Liu, Xuedong; Bortz, David M

2016-07-07

The in vitro migration of keratinocyte cell sheets displays behavioral and biochemical similarities to the in vivo wound healing response of keratinocytes in animal model systems. In both cases, ligand-dependent Epidermal Growth Factor Receptor (EGFR) activation is sufficient to elicit collective cell migration into the wound. Previous mathematical modeling studies of in vitro wound healing assays assume that physical connections between cells have a hindering effect on cell migration, but biological literature suggests a more complicated story. By combining mathematical modeling and experimental observations of collectively migrating sheets of keratinocytes, we investigate the role of cell-cell adhesion during in vitro keratinocyte wound healing assays. We develop and compare two nonlinear diffusion models of the wound healing process in which cell-cell adhesion either hinders or promotes migration. Both models can accurately fit the leading edge propagation of cell sheets during wound healing when using a time-dependent rate of cell-cell adhesion strength. The model that assumes a positive role of cell-cell adhesion on migration, however, is robust to changes in the leading edge definition and yields a qualitatively accurate density profile. Using RNAi for the critical adherens junction protein, α-catenin, we demonstrate that cell sheets with wild type cell-cell adhesion expression maintain migration into the wound longer than cell sheets with decreased cell-cell adhesion expression, which fails to exhibit collective migration. Our modeling and experimental data thus suggest that cell-cell adhesion promotes sustained migration as cells pull neighboring cells into the wound during wound healing. Copyright © 2016 Elsevier Ltd. All rights reserved.

Suppressive Effect of Hydroquinone, a Benzene Metabolite, on In Vitro Inflammatory Responses Mediated by Macrophages, Monocytes, and Lymphocytes

PubMed Central

Cho, Jae Youl

2008-01-01

We investigated the inhibitory effects of hydroquinone on cytokine release, phagocytosis, NO production, ROS generation, cell-cell/cell fibronectin adhesion, and lymphocyte proliferation. We found that hydroquinone suppressed the production of proinflammatory cytokines [tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6], secretion of toxic molecules [nitric oxide (NO) and reactive oxygen species (ROS)], phagocytic uptake of FITC-labeled dextran, upregulation of costimulatory molecules, U937 cell-cell adhesion induced by CD18 and CD29, and the proliferation of lymphocytes from the bone marrow and spleen. Considering that (1) environmental chemical stressors reduce the immune response of chronic cigarette smokers and children against bacterial and viral infections and that (2) workers in petroleum factories are at higher risk for cancer, our data suggest that hydroquinone might pathologically inhibit inflammatory responses mediated by monocytes, macrophages, and lymphocytes. PMID:19148301

HMC05, Herbal Formula, Inhibits TNF-α-Induced Inflammatory Response in Human Umbilical Vein Endothelial Cells

PubMed Central

Lee, Jong Suk; Park, Su-Young; Thapa, Dinesh; Kim, Ah Ra; Shin, Heung-Mook; Kim, Jung-Ae

2011-01-01

Vascular inflammation has been implicated in the progression of cardiovascular diseases such as atherosclerosis. In the present study, we found that HMC05, an extract from eight different herbal mixtures, dose-dependently inhibited tumor necrosis factor-α (TNF-α)-induced adhesion of monocytes to endothelial cells. Such inhibitory effect of HMC05 correlated with suppressed expression of monocyte chemoattractant protein-1, CC chemokine receptor 2, vascular cell adhesion molecule-1 and intercellular cell adhesion molecule-1. In addition, HMC05 significantly inhibited production of reactive oxygen species (ROS) and nuclear factor (NF)-κB activation by TNF-α. Those inhibitory effects of HMC05 (1–10 μg mL−1) on the TNF-α-induced inflammatory event was similar to those of berberine (1–10 μM), which is a major component of HMC05 and one of herbal compounds known to have vasorelaxing and lipid-lowering activities. However, berberine significantly reduced the viability of HUVECs in a time- and concentration-dependent manner. In contrast, HMC05 (1–10 μg ml−1) did not affect the cell viability for up to 48 h treatment. In conclusion, we propose that HMC05 may be a safe and potent herbal formula against vascular inflammation, and its action may be attributable to the inhibition of ROS- and NF-κB-dependent expression of adhesion molecules and chemokines. PMID:19736220

Overexpression of stress-inducible OsBURP16, the β subunit of polygalacturonase 1, decreases pectin content and cell adhesion and increases abiotic stress sensitivity in rice

PubMed Central

Liu, Huanhuan; Ma, Yan; Chen, Na; Guo, Siyi; Liu, Huili; Guo, Xiaoyu; Chong, Kang; Xu, Yunyuan

2014-01-01

Polygalacturonase (PG), one of the hydrolases responsible for cell wall pectin degradation, is involved in organ consenescence and biotic stress in plants. PG1 is composed of a catalytic subunit, PG2, and a non-catalytic PG1β subunit. OsBURP16 belongs to the PG1β-like subfamily of BURP-family genes and encodes one putative PG1β subunit precursor in rice (Oryza sativa L.). Transcription of OsBURP16 is induced by cold, salinity and drought stresses, as well as by abscisic acid (ABA) treatment. Analysis of plant survival rates, relative ion leakage rates, accumulation levels of H2O2 and water loss rates of leaves showed that overexpression of OsBURP16 enhanced sensitivity to cold, salinity and drought stresses compared with controls. Young leaves of Ubi::OsBURP16 transgenic plants showed reduced cell adhesion and increased cuticular transpiration rate. Mechanical strength measurement of Ubi::OsBURP16 plants showed that reduced force was required to break leaves as compared with wild type. Transgenic rice showed enhanced PG activity and reduced pectin content. All these results suggested that overexpression of OsBURP16 caused pectin degradation and affected cell wall integrity as well as transpiration rate, which decreased tolerance to abiotic stresses. The cell wall is a barrier against biotic and abiotic stresses. Overexpression of stress-inducible OsBURP16, the beta-subunit of polygalacturonase 1, decreases pectin contents and cell adhesion in rice. Analyses of plant survival, ion leakage, H2O2 levels, and leaf water loss showed that these effects of overexpression were accompanied by enhanced sensitivity to cold, salinity and drought compared to the wild-type. Our data therefore provide new information on links between polygalacturonase activity and abiotic stress resistance in rice. PMID:24237159

In vitro dentin barrier cytotoxicity testing of some dental restorative materials.

PubMed

Jiang, R D; Lin, H; Zheng, G; Zhang, X M; Du, Q; Yang, M

2017-03-01

To investigate the cytotoxicity of four dental restorative materials in three-dimensional (3D) L929 cell cultures using a dentin barrier test. The cytotoxicities of light-cured glass ionomer cement (Vitrebond), total-etching adhesive (GLUMA Bond5), and two self-etching adhesives (GLUMA Self Etch and Single Bond Universal) were evaluated. The permeabilities of human dentin disks with thicknesses of 300, 500, and 1000μm were standardized using a hydraulic device. Test materials and controls were applied to the occlusal side of human dentin disks. The 3D-cell scaffolds were placed beneath the dentin disks. After a 24-h contact with the dentin barrier test device, cell viabilities were measured by performing MTT assays. Statistical analysis was performed using the Mann-Whitney U test. The mean (SD) permeabilities of the 300-μm, 500-μm, and 1000-μm dentin disks were 0.626 (0.214), 0.219 (0.0387) and 0.089 (0.028) μlmin -1 cm -2 cm H 2 O -1 . Vitrebond was severely cytotoxic, reducing the cell viability to 10% (300-μm disk), 17% (500μm), and 18% (1000μm). GLUMA Bond5 reduced the cell viability to 40% (300μm), 83% (500μm), and 86% (1000μm), showing moderate cytotoxicity (300-μm) and non-cytotoxicity (500-μm and 1000-μm). Single Bond Universal and GLUMA Self Etch did not significantly reduce cell viability, regardless of the dentin thicknesses, which characterized them as non-cytotoxic. Cytotoxicity varied with the materials tested and the thicknesses of the dentin disks. The tested cytotoxicity of materials applied on 300-, 500-, and 1000-μm dentin disks indicates that the clinical use of the test materials (excepting self-etching adhesives) in deep cavities poses a potential risk of damage to the pulp tissues to an extent, depending on the thickness of the remaining dentin. Copyright © 2017 Elsevier Ltd. All rights reserved.

Glucocorticoids Suppress Renal Cell Carcinoma Progression by Enhancing Na,K-ATPase Beta-1 Subunit Expression

PubMed Central

Huynh, Thu P.; Barwe, Sonali P.; Lee, Seung J.; McSpadden, Ryan; Franco, Omar E.; Hayward, Simon W.; Damoiseaux, Robert; Grubbs, Stephen S.; Petrelli, Nicholas J.; Rajasekaran, Ayyappan K.

2015-01-01

Glucocorticoids are commonly used as palliative or chemotherapeutic clinical agents for treatment of a variety of cancers. Although steroid treatment is beneficial, the mechanisms by which steroids improve outcome in cancer patients are not well understood. Na,K-ATPase beta-subunit isoform 1 (NaK-β1) is a cell-cell adhesion molecule, and its expression is down-regulated in cancer cells undergoing epithelial-to mesenchymal-transition (EMT), a key event associated with cancer progression to metastatic disease. In this study, we performed high-throughput screening to identify small molecules that could up-regulate NaK-β1 expression in cancer cells. Compounds related to the glucocorticoids were identified as drug candidates enhancing NaK-β1 expression. Of these compounds, triamcinolone, dexamethasone, and fluorometholone were validated to increase NaK-β1 expression at the cell surface, enhance cell-cell adhesion, attenuate motility and invasiveness and induce mesenchymal to epithelial like transition of renal cell carcinoma (RCC) cells in vitro. Treatment of NaK-β1 knockdown cells with these drug candidates confirmed that these compounds mediate their effects through up-regulating NaK-β1. Furthermore, we demonstrated that these compounds attenuate tumor growth in subcutaneous RCC xenografts and reduce local invasiveness in orthotopically-implanted tumors. Our results strongly indicate that the addition of glucocorticoids in the treatment of RCC may improve outcome for RCC patients by augmenting NaK-β1 cell-cell adhesion function. PMID:25836370

Sulforaphane inhibits restenosis by suppressing inflammation and the proliferation of vascular smooth muscle cells.

PubMed

Kwon, Jin-Sook; Joung, Hosouk; Kim, Yong Sook; Shim, Young-Sun; Ahn, Youngkeun; Jeong, Myung Ho; Kee, Hae Jin

2012-11-01

Sulforaphane, a naturally occurring organosulfur compound in broccoli, has chemopreventive properties in cancer. However, the effects of sulforaphane in vascular diseases have not been examined. We therefore aimed to investigate the effects of sulforaphane on vascular smooth muscle cell (VSMC) proliferation and neointimal formation and the related mechanisms. The expression of vascular cell adhesion molecule 1 (VCAM-1) and intercellular adhesion molecule 1 (ICAM-1) was examined in VSMCs. The nuclear translocation of nuclear factor-κB (NF-κB) and GATA6 expression was examined in VSMCs and in a carotid artery injury model by Western blot and immunohistochemistry. We also investigated whether local delivery of sulforaphane affected neointimal formation. Sulforaphane inhibited the mRNA and protein expression of VCAM-1 induced by tumor necrosis factor (TNF)-α in VSMCs. Treatment of VSMCs with sulforaphane blocked TNF-α-induced IκBα degradation and NF-κB p65 and GATA6 expression. Furthermore, NF-κB p65 and GATA6 expression were reduced in sulforaphane-treated carotid injury sections. Notably, binding of GATA6 to the VCAM-1 promoter was dramatically reduced by sulforaphane. The MTT, BrdU incorporation, and in vitro scratch assays revealed that the proliferation and migration of VSMCs were reduced by sulforaphane. Furthermore, local administration of sulforaphane significantly reduced neointima formation 14 days after vascular injury in rats. Our results indicate that sulforaphane inhibits neointima formation via targeting of adhesion molecules through the suppression of NF-κB/GATA6. Furthermore, sulforaphane regulates migration and proliferation in VSMCs. Sulforaphane may be a potential therapeutic agent for preventing restenosis after vascular injury. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Retinoids induce integrin-independent lymphocyte adhesion through RAR-α nuclear receptor activity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Whelan, Jarrett T.; Wang, Lei; Chen, Jianming

2014-11-28

Highlights: • Transcription and translation are required for retinoid-induced lymphocyte adhesion. • RAR activation is sufficient to induced lymphocyte cell adhesion. • Vitamin D derivatives inhibit RAR-prompted lymphocyte adhesion. • Adhesion occurs through a novel binding site within ADAM disintegrin domains. • RARα is a key nuclear receptor for retinoid-dependent lymphocyte cell adhesion. - Abstract: Oxidative metabolites of vitamin A, in particular all-trans-retinoic acid (atRA), have emerged as key factors in immunity by specifying the localization of immune cells to the gut. Although it is appreciated that isomers of retinoic acid activate the retinoic acid receptor (RAR) and retinoid Xmore » receptor (RXR) family of nuclear receptors to elicit cellular changes, the molecular details of retinoic acid action remain poorly defined in immune processes. Here we employ a battery of agonists and antagonists to delineate the specific nuclear receptors utilized by retinoids to evoke lymphocyte cell adhesion to ADAM (adisintegrin and metalloprotease) protein family members. We report that RAR agonism is sufficient to promote immune cell adhesion in both immortal and primary immune cells. Interestingly, adhesion occurs independent of integrin function, and mutant studies demonstrate that atRA-induced adhesion to ADAM members required a distinct binding interface(s) as compared to integrin recognition. Anti-inflammatory corticosteroids as well as 1,25-(OH){sub 2}D{sub 3}, a vitamin D metabolite that prompts immune cell trafficking to the skin, potently inhibited the observed adhesion. Finally, our data establish that induced adhesion was specifically attributable to the RAR-α receptor isotype. The current study provides novel molecular resolution as to which nuclear receptors transduce retinoid exposure into immune cell adhesion.« less

Molecules mediating adhesion of T and B cells, monocytes and granulocytes to vascular endothelial cells.

PubMed Central

Prieto, J; Beatty, P G; Clark, E A; Patarroyo, M

1988-01-01

Leucocytes interact with vascular endothelial cells (EC), and adhesion between these two cell types in vitro is modulated by phorbol ester. Monocytes were found to display the highest basal adhesion to EC, followed by Epstein-Barr virus-immortalized normal B cells (EBV-B), T cells and granulocytes. Phorbol ester treatment increased the adhesion of all types of leucocytes, except monocytes. In the presence of this compound, monoclonal antibody 60.3 to GP90 (CD18, a leucocyte-adhesion protein which is non-covalently associated to either GP160, GP155, or GP130) was found to inhibit the adhesion of the four types of leucocytes to a considerable extent, while anti-lymphocyte function-associated antigen-1 (LFA-1) antibody to GP160 (CD11a) inhibited the adhesion of T and B cells only. Antibody 60.1 to GP155 (CD11b) had a major inhibitory activity exclusively on granulocytes, while antibody LB-2, which recognizes a distinct adhesion molecule (GP84) and, in contrast to the previous antibodies, reacts with EC, mainly inhibited adhesion of EBV-B and did not increase the inhibition obtained with antibody 60.3 alone. Fab fragments of antibody 60.3 inhibited leucocyte adhesion more efficiently, in either the absence or presence of phorbol ester, than the intact antibody molecule. It is concluded the GP90, either alone or associated to the larger glycoproteins, mediates the adhesion in all types of leucocytes, while GP84 mediates the adhesion of the activated B cells. Images Figure 2 PMID:3259203

Circulating vascular cell adhesion molecule-1 in pre-eclampsia, gestational hypertension, and normal pregnancy: evidence of selective dysregulation of vascular cell adhesion molecule-1 homeostasis in pre-eclampsia.

PubMed

Higgins, J R; Papayianni, A; Brady, H R; Darling, M R; Walshe, J J

1998-08-01

Our purpose was to investigate circulating levels of vascular cell adhesion molecule-1 in the peripheral and uteroplacental circulations during normotensive and hypertensive pregnancies. This prospective observational study involved 2 patient groups. Group 1 consisted of 22 women with pre-eclampsia and 30 normotensive women followed up longitudinally through pregnancy and post partum. There were an additional 13 women with established gestational hypertension. Group 2 consisted of 20 women with established pre-eclampsia and 19 normotensive control subjects undergoing cesarean delivery. Plasma levels of vascular cell adhesion molecule-1 were measured in blood drawn from the antecubital vein (group 1) and from both the antecubital and uterine veins (group 2). Data were analyzed by analysis of variance. In group 1 vascular cell adhesion molecule-1 levels did not change significantly throughout normal pregnancy and post partum. Women with established pre-eclampsia had increased vascular cell adhesion molecule-1 levels compared with the normotensive pregnancy group (P = .01). Vascular cell adhesion molecule-1 levels were not elevated in women with established gestational hypertension. In group 2 significantly higher levels of vascular cell adhesion molecule-1 were detected in the uteroplacental (P < .0001) and peripheral (P < .0001) circulations of pre-eclamptic women by comparison with normotensive women. In the pre-eclamptic group there was a tendency toward higher vascular cell adhesion molecule-1 levels in the peripheral circulation than in the uteroplacental circulation (P = .06). In contrast to vascular cell adhesion molecule-1, circulating levels of E-selectin and intercellular adhesion molecule-1, other major leukocyte adhesion molecules expressed by the endothelium, were not different in pre-eclamptic and normotensive pregnancies. Established pre-eclampsia is characterized by selective dysregulation of vascular cell adhesion molecule-1 homeostasis. This event is not an early preclinical feature of pre-eclampsia, does not persist post partum, is not a feature of nonproteinuric gestational hypertension, and is not observed with other major leukocyte adhesion molecules. Induction of vascular cell adhesion molecule-1 expression in pre-eclampsia may contribute to leukocyte-mediated tissue injury in this condition or may reflect perturbation of other, previously unrecognized, functions of this molecule in pregnancy.

The CD44-initiated pathway of T-cell extravasation uses VLA-4 but not LFA-1 for firm adhesion

PubMed Central

Siegelman, Mark H.; Stanescu, Diana; Estess, Pila

2000-01-01

Leukocytes extravasate from the blood in response to physiologic or pathologic demands by means of complementary ligand interactions between leukocytes and endothelial cells. The multistep model of leukocyte extravasation involves an initial transient interaction (“rolling” adhesion), followed by secondary (firm) adhesion. We recently showed that binding of CD44 on activated T lymphocytes to endothelial hyaluronan (HA) mediates a primary adhesive interaction under shear stress, permitting extravasation at sites of inflammation. The mechanism for subsequent firm adhesion has not been elucidated. Here we demonstrate that the integrin VLA-4 is used in secondary adhesion after CD44-mediated primary adhesion of human and mouse T cells in vitro, and by mouse T cells in an in vivo model. We show that clonal cell lines and polyclonally activated normal T cells roll under physiologic shear forces on hyaluronate and require VCAM-1, but not ICAM-1, as ligand for subsequent firm adhesion. This firm adhesion is also VLA-4 dependent, as shown by antibody inhibition. Moreover, in vivo short-term homing experiments in a model dependent on CD44 and HA demonstrate that superantigen-activated T cells require VLA-4, but not LFA-1, for entry into an inflamed peritoneal site. Thus, extravasation of activated T cells initiated by CD44 binding to HA depends upon VLA-4–mediated firm adhesion, which may explain the frequent association of these adhesion receptors with diverse chronic inflammatory processes. PMID:10712440

Sickle red cell-endothelium interactions.

PubMed

Kaul, Dhananjay K; Finnegan, Eileen; Barabino, Gilda A

2009-01-01

Periodic recurrence of painful vaso-occlusive crisis is the defining feature of sickle cell disease. Among multiple pathologies associated with this disease, sickle red cell-endothelium interaction has been implicated as a potential initiating mechanism in vaso-occlusive events. This review focuses on various interrelated mechanisms involved in human sickle red cell adhesion. We discuss in vitro and microcirculatory findings on sickle red cell adhesion, its potential role in vaso-occlusion, and the current understanding of receptor-ligand interactions involved in this pathological phenomenon. In addition, we discuss the contribution of other cellular interactions (leukocytes recruitment and leukocyte-red cell interaction) to vaso-occlusion, as observed in transgenic sickle mouse models. Emphasis is given to recently discovered adhesion molecules that play a predominant role in mediating human sickle red cell adhesion. Finally, we analyze various therapeutic approaches for inhibiting sickle red cell adhesion by targeting adhesion molecules and also consider therapeutic strategies that target stimuli involved in endothelial activation and initiation of adhesion.

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

NASA Astrophysics Data System (ADS)

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

1995-08-01

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

Centrifugation assay for measuring adhesion of serially passaged bovine chondrocytes to polystyrene surfaces.

PubMed

Kaplan, David S; Hitchins, Victoria M; Vegella, Thomas J; Malinauskas, Richard A; Ferlin, Kimberly M; Fisher, John P; Frondoza, Carmelita G

2012-07-01

A major obstacle in chondrocyte-based therapy for cartilage repair is the limited availability of cells that maintain their original phenotype. Propagation of chondrocytes as monolayer cultures on polystyrene surfaces is used extensively for amplifying cell numbers. However, chondrocytes undergo a phenotypic shift when propagated in this manner and display characteristics of more adherent fibroblastic cells. Little information is available about the effect of this phenotypic shift on cellular adhesion properties. We evaluated changes in adhesion property as bovine chondrocytes were serially propagated up to five passages in monolayer culture using a centrifugation cell adhesion assay, which was based on counting of cells before and after being exposed to centrifugal dislodgement forces of 120 and 350 g. Chondrocytes proliferated well in a monolayer culture with doubling times of 2-3 days, but they appeared more fibroblastic and exhibited elongated cell morphology with continued passage. The centrifugation cell adhesion assay showed that chondrocytes became more adhesive with passage as the percentage of adherent cells after centrifugation increased and was not statistically different from the adhesion of the fibroblast cell line, L929, starting at passage 3. This increased adhesiveness correlated with a shift to a fibroblastic morphology and increased collagen I mRNA expression starting at passage 2. Our findings indicate that the centrifugation cell adhesion assay may serve as a reproducible tool to track alterations in chondrocyte phenotype during their extended propagation in culture.

Effect of Rebamipide, a Novel Antiulcer Agent, on Helicobacter pylori Adhesion to Gastric Epithelial Cells

PubMed Central

Hayashi, Shunji; Sugiyama, Toshiro; Amano, Ken-Ichi; Isogai, Hiroshi; Isogai, Emiko; Aihara, Miki; Kikuchi, Mikio; Asaka, Masahiro; Yokota, Kenji; Oguma, Keiji; Fujii, Nobuhiro; Hirai, Yoshikazu

1998-01-01

Helicobacter pylori is a major etiological agent in gastroduodenal disorders. The adhesion of H. pylori to human gastric epithelial cells is the initial step of H. pylori infection. Inhibition of H. pylori adhesion is thus a therapeutic target in the prevention of H. pylori infection. Experiments were performed to evaluate the effect of rebamipide, a novel antiulcer agent, on H. pylori adhesion to gastric epithelial cells. MKN-28 and MKN-45 cells, derived from human gastric carcinomas, were used as target cells. Ten H. pylori strains isolated from patients with chronic gastritis and gastric ulcer were used in the study. We evaluated the effect of rebamipide on H. pylori adhesion to MKN-28 and MKN-45 cells quantitatively using our previously established enzyme-linked immunosorbent assay. The adhesion of H. pylori to MKN-28 and MKN-45 cells was significantly inhibited by pretreatment of these cells with 100 μg of rebamipide per ml. However, the adhesion was not affected by the pretreatment of H. pylori with rebamipide. On the other hand, the viabilities of H. pylori, MKN-28 cells, and MKN-45 cells were not affected by rebamipide. Our studies suggest that rebamipide inhibits the adhesion of H. pylori to gastric epithelial cells. PMID:9687380

The effect of the physical properties of the substrate on the kinetics of cell adhesion and crawling studied by an axisymmetric diffusion-energy balance coupled model.

PubMed

Samadi-Dooki, Aref; Shodja, Hossein M; Malekmotiei, Leila

2015-05-14

In this paper an analytical approach to study the effect of the substrate physical properties on the kinetics of adhesion and motility behavior of cells is presented. Cell adhesion is mediated by the binding of cell wall receptors and substrate's complementary ligands, and tight adhesion is accomplished by the recruitment of the cell wall binders to the adhesion zone. The binders' movement is modeled as their axisymmetric diffusion in the fluid-like cell membrane. In order to preserve the thermodynamic consistency, the energy balance for the cell-substrate interaction is imposed on the diffusion equation. Solving the axisymmetric diffusion-energy balance coupled equations, it turns out that the physical properties of the substrate (substrate's ligand spacing and stiffness) have considerable effects on the cell adhesion and motility kinetics. For a rigid substrate with uniform distribution of immobile ligands, the maximum ligand spacing which does not interrupt adhesion growth is found to be about 57 nm. It is also found that as a consequence of the reduction in the energy dissipation in the isolated adhesion system, cell adhesion is facilitated by increasing substrate's stiffness. Moreover, the directional movement of cells on a substrate with gradients in mechanical compliance is explored with an extension of the adhesion formulation. It is shown that cells tend to move from soft to stiff regions of the substrate, but their movement is decelerated as the stiffness of the substrate increases. These findings based on the proposed theoretical model are in excellent agreement with the previous experimental observations.

Hydroxycarbamide reduces eosinophil adhesion and degranulation in sickle cell anaemia patients.

PubMed

Pallis, Flavia Rubia; Conran, Nicola; Fertrin, Kleber Yotsumoto; Olalla Saad, Sara Terezinha; Costa, Fernando Ferreira; Franco-Penteado, Carla Fernanda

2014-01-01

Inflammation, leucocyte and red cell adhesion to the endothelium contribute to the pathogenesis of sickle cell anaemia. Neutrophils appear to be important for vaso-occlusion, however, eosinophils may also participate in this phenomenon. The role of eosinophils in the pathophysiology of sickle cell anaemia (SCA) and the effect of hydroxycarbamide (HC) therapy on the functional properties of these cells are not understood. Patients with SCA and those on HC therapy (SCAHC) were included in the study. SCAHC individuals presented significantly lower absolute numbers of eosinophils than SCA. Furthermore, SCAHC eosinophils demonstrated significantly lower adhesive properties, compared to SCA eosinophils. SCA and SCAHC eosinophils presented greater spontaneous migration when compared with control eosinophils. Baseline eosinophil peroxidase and reactive oxygen species release was higher for SCA individuals than for control individuals, as were plasma levels of eosinophil derived neurotoxin. SCAHC eosinophil degranulation was lower than that of SCA eosinophil degranulation. Eotaxin-1 and RANTES levels were higher in the plasma of SCA and SCAHC individuals, when compared with controls. These data suggest that eosinophils exist in an activated state in SCA and indicate that these cells play a role in the vaso-occlusive process. The exact mechanism by which HC may alter SCA eosinophil properties is not clear. © 2013 John Wiley & Sons Ltd.

Synaptopodin couples epithelial contractility to α-actinin-4–dependent junction maturation

PubMed Central

Kannan, Nivetha

2015-01-01

The epithelial junction experiences mechanical force exerted by endogenous actomyosin activities and from interactions with neighboring cells. We hypothesize that tension generated at cell–cell adhesive contacts contributes to the maturation and assembly of the junctional complex. To test our hypothesis, we used a hydraulic apparatus that can apply mechanical force to intercellular junction in a confluent monolayer of cells. We found that mechanical force induces α-actinin-4 and actin accumulation at the cell junction in a time- and tension-dependent manner during junction development. Intercellular tension also induces α-actinin-4–dependent recruitment of vinculin to the cell junction. In addition, we have identified a tension-sensitive upstream regulator of α-actinin-4 as synaptopodin. Synaptopodin forms a complex containing α-actinin-4 and β-catenin and interacts with myosin II, indicating that it can physically link adhesion molecules to the cellular contractile apparatus. Synaptopodin depletion prevents junctional accumulation of α-actinin-4, vinculin, and actin. Knockdown of synaptopodin and α-actinin-4 decreases the strength of cell–cell adhesion, reduces the monolayer permeability barrier, and compromises cellular contractility. Our findings underscore the complexity of junction development and implicate a control process via tension-induced sequential incorporation of junctional components. PMID:26504173

Exposure to Bordetella pertussis adenylate cyclase toxin affects integrin-mediated adhesion and mechanics in alveolar epithelial cells.

PubMed

Angely, Christelle; Nguyen, Ngoc-Minh; Andre Dias, Sofia; Planus, Emmanuelle; Pelle, Gabriel; Louis, Bruno; Filoche, Marcel; Chenal, Alexandre; Ladant, Daniel; Isabey, Daniel

2017-08-01

The adenylate cyclase (CyaA) toxin is a major virulent factor of Bordetella pertussis, the causative agent of whooping cough. CyaA toxin is able to invade eukaryotic cells where it produces high levels of cyclic adenosine monophosphate (cAMP) affecting cellular physiology. Whether CyaA toxin can modulate cell matrix adhesion and mechanics of infected cells remains largely unknown. In this study, we use a recently proposed multiple bond force spectroscopy (MFS) with an atomic force microscope to assess the early phase of cell adhesion (maximal detachment and local rupture forces) and cell rigidity (Young's modulus) in alveolar epithelial cells (A549) for toxin exposure <1 h. At 30 min of exposure, CyaA toxin has a minimal effect on cell viability (>95%) at CyaA concentration of 0.5 nM, but a significant effect (≈81%) at 10 nM. MFS performed on A549 for three different concentrations (0.5, 5 and 10 nM) demonstrates that CyaA toxin significantly affects both cell adhesion (detachment forces are decreased) and cell mechanics (Young's modulus is increased). CyaA toxin (at 0.5 nM) assessed at three indentation/retraction speeds (2, 5 and 10 μm/s) significantly affects global detachment forces, local rupture events and Young modulus compared with control conditions, while an enzymatically inactive variant CyaAE5 has no effect. These results reveal the loading rate dependence of the multiple bonds newly formed between the cell and integrin-specific coated probe as well as the individual bond kinetics which are only slightly affected by the patho-physiological dose of CyaA toxin. Finally, theory of multiple bond force rupture enables us to deduce the bond number N which is reduced by a factor of 2 upon CyaA exposure (N ≈ 6 versus N ≈ 12 in control conditions). MFS measurements demonstrate that adhesion and mechanical properties of A549 are deeply affected by exposure to the CyaA toxin but not to an enzymatically inactive variant. This indicates that the alteration of cell mechanics triggered by CyaA is a consequence of the increase in intracellular cAMP in these target cells. These results suggest that mechanical and adhesion properties of the cells appear as pertinent markers of cytotoxicity of CyaA toxin. © 2017 Société Française des Microscopies and Société de Biologie Cellulaire de France. Published by John Wiley & Sons Ltd.

Doxycycline reduces the migration of tuberous sclerosis complex-2 null cells - effects on RhoA-GTPase and focal adhesion kinase

PubMed Central

Ng, Ho Yin; Oliver, Brian Gregory George; Burgess, Janette Kay; Krymskaya, Vera P; Black, Judith Lee; Moir, Lyn M

2015-01-01

Lymphangioleiomyomatosis (LAM) is associated with dysfunction of the tuberous sclerosis complex (TSC) leading to enhanced cell proliferation and migration. This study aims to examine whether doxycycline, a tetracycline antibiotic, can inhibit the enhanced migration of TSC2-deficient cells, identify signalling pathways through which doxycycline works and to assess the effectiveness of combining doxycycline with rapamycin (mammalian target of rapamycin complex 1 inhibitor) in controlling cell migration, proliferation and wound closure. TSC2-positive and TSC2-negative mouse embryonic fibroblasts (MEF), 323-TSC2-positive and 323-TSC2-null MEF and Eker rat uterine leiomyoma (ELT3) cells were treated with doxycycline or rapamycin alone, or in combination. Migration, wound closure and proliferation were assessed using a transwell migration assay, time-lapse microscopy and manual cell counts respectively. RhoA-GTPase activity, phosphorylation of p70S6 kinase (p70S6K) and focal adhesion kinase (FAK) in TSC2-negative MEF treated with doxycycline were examined using ELISA and immunoblotting techniques. The enhanced migration of TSC2-null cells was reduced by doxycycline at concentrations as low as 20 pM, while the rate of wound closure was reduced at 2–59 μM. Doxycycline decreased RhoA-GTPase activity and phosphorylation of FAK in these cells but had no effect on the phosphorylation of p70S6K, ERK1/2 or AKT. Combining doxycycline with rapamycin significantly reduced the rate of wound closure at lower concentrations than achieved with either drug alone. This study shows that doxycycline inhibits TSC2-null cell migration. Thus doxycycline has potential as an anti-migratory agent in the treatment of diseases with TSC2 dysfunction. PMID:26282580

Focal Adhesion-Independent Cell Migration.

PubMed

Paluch, Ewa K; Aspalter, Irene M; Sixt, Michael

2016-10-06

Cell migration is central to a multitude of physiological processes, including embryonic development, immune surveillance, and wound healing, and deregulated migration is key to cancer dissemination. Decades of investigations have uncovered many of the molecular and physical mechanisms underlying cell migration. Together with protrusion extension and cell body retraction, adhesion to the substrate via specific focal adhesion points has long been considered an essential step in cell migration. Although this is true for cells moving on two-dimensional substrates, recent studies have demonstrated that focal adhesions are not required for cells moving in three dimensions, in which confinement is sufficient to maintain a cell in contact with its substrate. Here, we review the investigations that have led to challenging the requirement of specific adhesions for migration, discuss the physical mechanisms proposed for cell body translocation during focal adhesion-independent migration, and highlight the remaining open questions for the future.

Regulating the migration of smooth muscle cells by a vertically distributed poly(2-hydroxyethyl methacrylate) gradient on polymer brushes covalently immobilized with RGD peptides.

PubMed

Wu, Sai; Du, Wang; Duan, Yiyuan; Zhang, Deteng; Liu, Yixiao; Wu, Bingbing; Zou, Xiaohui; Ouyang, Hongwei; Gao, Changyou

2018-05-30

The gradient localization of biological cues is of paramount importance to guide directional migration of cells. In this study, poly(2-hydroxyethyl methacrylate-co-glycidyl methacrylate)-block- poly(2-hydroxyethyl methacrylate) (P(HEMA-co-GMA)-b-PHEMA) brushes with a uniform underneath P(HEMA-co-GMA) layer and a gradient thickness of PHEMA blocks were prepared by using surface-initiated atom-transfer radical polymerization and a dynamically controlled polymerization process. The polymer chains were subsequently functionalized with the cell-adhesive arginine-glycine-aspartic acid (RGD) peptides by reaction with the glycidyl groups, and their structures and properties were characterized by X-ray photoelectron spectrometry (XPS), quartz crystal microbalance with dissipation (QCM-D) and air contact angle. Adhesion and migration processes of smooth muscle cells (SMCs) were then studied. Compared with those on the sufficiently exposed RGD surface, the cell adhesion and mobility were well maintained when the RGD peptides were localized at 18.9 nm depth, whereas the adhesion, spreading and migration rate of SMCs were significantly impaired when the RGD peptides were localized at a depth of 38.4 nm. On the RGD depth gradient surface, the SMCs exhibited preferential orientation and enhanced directional migration toward the direction of reduced thickness of the second PHEMA brushes. Half of the cells were oriented within ± 30° to the x-axis direction, and 72% of the cells moved directionally at the optimal conditions. Cell adhesion strength, arrangement of cytoskeleton, and gene and protein expression levels of adhesion-related proteins were studied to corroborate the mechanisms, demonstrating that the cell mobility is regulated by the complex and synergetic intracellular signals resulted from the difference in surface properties. Cell migration is of paramount importance for the processes of tissue repair and regeneration. So far, the gradient localization of biological cues perpendicular to the substrate, which is the usual case for the biological signaling molecules to locate in ECM in vivo, has been scarcely studied, and has not been used to guide the directional migration of cells. In this study, we prepare a depth gradient of RGD peptides along the polymer chains, which is used to guide the directional migration of SMCs after a second hydrophilic bock is prepared in a gradient manner. For the first time the directional migration of SMCs is achieved under the guidance of a depth gradient of RGD ligands. The mechanisms of different cell migration abilities are further discussed based on the results of cell adhesion, cell adhesion force, cytoskeleton alignment and expression of relative proteins and genes. This work paves a new strategy by fabricating a gradient polymer brushes with immobilized bioactive molecules to dominate the directional cell migration, and elucidates the mechanisms underlining the biased migration along RGD depth localization gradients, shedding a light for the design of novel biomaterials to control and guide cell migration and invasion. Copyright © 2018 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

ERK5/KLF2 activation is involved in the reducing effects of puerarin on monocyte adhesion to endothelial cells and atherosclerotic lesion in apolipoprotein E-deficient mice.

PubMed

Deng, Yan; Lei, Tingwen; Li, Hongmei; Mo, Xiaochuan; Wang, Zhuting; Ou, Hailong

2018-04-30

Puerarin has properties of anti-oxidation and anti-inflammation, which has been demonstrated protective effects in atherosclerosis and other cardiovascular diseases. However, the detail molecular mechanism still remains unclear. Here, we determined whether the atheroprotective effect of puerarin was by reducing monocyte adhesion and explored the underlying mechanism. The results showed that puerarin dose- and time-dependently reduced oxLDL-induced monocyte THP-1 adhesion to HUVECs and the expression of adhesion-related genes such as VCAM-1, ICAM-1, MCP-1 and IL-8 in HUVECs. Puerarin activated ERK5 phosphorylation and up-regulated expressions of downstream KLF2 and its targeted genes endothelial nitric oxide synthase and thrombomodulin. However, the protective effects were reversed by ERK5/KLF2 pathway inhibitor XDM8-92, BIX02189 or KLF2 siRNA suggesting the pathway involved in the function. The ex vivo assay, in which THP-1 adhesion to endothelium isolated from apoE-/- mice received various treatment further confirmed the results from HUVECs. Finally, we found that the atherosclerotic lesions in both cross sections at aortic root and whole aorta were significantly reduced in high fat-diet (HFD) mice with puerarin treatment compared with the HFD-only mice, but were increased respectively by 76% and 71% in XMD8-92 group, and 82% and 73% in BIX02189 group. Altogether, the data revealed that puerarin inhibited the monocyte adhesion in vitro and in vivo and thus reduced atherosclerotic lesions in apoE-/- mice; the protective effects were mediated by activation of ERK5/KLF2 signaling pathway. Our findings advance the understanding of puerarin function in atherosclerosis and point out a way to prevent the disease. Copyright © 2018. Published by Elsevier B.V.

Impedimetric Analysis of the Effect of Decellularized Porcine Heart Scaffold on Human Fibrosarcoma, Endothelial, and Cardiomyocyte Cell Lines

PubMed Central

Bäcker, Henrik; Polgár, Livia; Soós, Pal; Lajkó, Eszter; Láng, Orsolya; Merkely, Bela; Szabó, Gabor; Dohmen, Pascal M.; Weymann, Alexander; Kőhidai, Laszlo

2017-01-01

Background Experiments on porcine heart scaffold represent significant assays in development of immunoneutral materials for cardiac surgery. Characterization of cell-cell and cell-scaffold interactions is essential to understand the homing process of cardiac cells into the scaffolds. Material/Methods In the present study, the highly sensitive and real-time impedimetric technique of xCELLigence SP was used to monitor cell adhesion, which is the key process of recellularization in heart scaffolds. Our objectives were: (i) to characterize the effect of decellularized porcine heart scaffold on cell adhesion of human cardiovascular cells potentially used in the recellularization process; and (ii) to investigate cell-extracellular matrix element interactions for building artificial multi-layer systems, applied as cellular models of recellularization experiments. Human fibrosarcoma, endothelial, and cardiomyocyte cells were investigated and the effect of decellularized porcine heart scaffold (HS) and fibronectin on cell adhesion was examined. Adhesion was quantified as slope of curves. Results Heart scaffold had neutral effect on cardiomyocytes as well as on endothelial cells. Adhesion of cardiomyocytes was increased by fibronectin (1.480±0.021) compared to control (0.745±0.029). The combination of fibronectin and HS induced stronger adhesion of cardiomyocytes (2.407±0.634) than fibronectin alone. Endothelial and fibrosarcoma cells showed similarly strong adhesion profiles with marked enhancer effect by fibronectin. Conclusions Decellularized porcine HS does not inhibit adhesion of human cardiovascular cells at the cell biological level, while fibronectin has strong cell adhesion-inducer effect, as well as an enhancer effect on activity of HS. Consequently, decellularized porcine hearts could be used as scaffolds for recellularization with cardiomyocytes and endothelial cells with fibronectin acting as a regulator, leading to construction of working bioartificial hearts. PMID:28493851

Interaction of tumor and host cells with adhesion and extracellular matrix molecules in the development of multiple myeloma.

PubMed

Teoh, G; Anderson, K C

1997-02-01

Adhesion molecules play an important role in the growth regulation and migration of multiple myeloma (MM) cells. They mediate homing of MM cells to the bone marrow and MM cell to bone marrow stromal cell adhesion, with resultant interleukin-6 related autocrine and paracine growth and antiapoptotic affects. Their pattern of expression on tumor cells correlates with the development of plasma cell leukemia or extramedullary disease. Clinically, expression of adhesion molecules on tumor cells or in the serum has already shown prognostic utility. Finally, since adhesion molecules are involved at multiple steps in the pathogenesis of MM, therapeutic studies may target these molecules.

Sub-Inhibitory Concentrations of Trans-Cinnamaldehyde Attenuate Virulence in Cronobacter sakazakii in Vitro

PubMed Central

Amalaradjou, Mary Anne Roshni; Kim, Kwang Sik; Venkitanarayanan, Kumar

2014-01-01

Cronobacter sakazakii is a foodborne pathogen, which causes a life-threatening form of meningitis, necrotizing colitis and meningoencephalitis in neonates and children. Epidemiological studies implicate dried infant formula as the principal source of C. sakazakii. In this study, we investigated the efficacy of sub-inhibitory concentrations (SIC) of trans-cinnamaldehyde (TC), an ingredient in cinnamon, for reducing C. sakazakii virulence in vitro using cell culture, microscopy and gene expression assays. TC significantly (p ≤ 0.05) suppressed C. sakazakii adhesion to and invasion of human and rat intestinal epithelial cells, and human brain microvascular endothelial cells. In addition, TC inhibited C. sakazakii survival and replication in human macrophages. We also observed that TC reduced the ability of C. sakazakii to cause cell death in rat intestinal cells, by inhibiting nitric oxide production. Results from gene expression studies revealed that TC significantly downregulated the virulence genes critical for motility, host tissue adhesion and invasion, macrophage survival, and LPS (Lipopolysaccharide) synthesis in C. sakazakii. The efficacy of TC in attenuating these major virulence factors in C. sakazakii underscores its potential use in the prevention and/or control of infection caused by this pathogen. PMID:24837831

Sub-inhibitory concentrations of trans-cinnamaldehyde attenuate virulence in Cronobacter sakazakii in vitro.

PubMed

Amalaradjou, Mary Anne Roshni; Kim, Kwang Sik; Venkitanarayanan, Kumar

2014-05-15

Cronobacter sakazakii is a foodborne pathogen, which causes a life-threatening form of meningitis, necrotizing colitis and meningoencephalitis in neonates and children. Epidemiological studies implicate dried infant formula as the principal source of C. sakazakii. In this study, we investigated the efficacy of sub-inhibitory concentrations (SIC) of trans-cinnamaldehyde (TC), an ingredient in cinnamon, for reducing C. sakazakii virulence in vitro using cell culture, microscopy and gene expression assays. TC significantly (p ≤ 0.05) suppressed C. sakazakii adhesion to and invasion of human and rat intestinal epithelial cells, and human brain microvascular endothelial cells. In addition, TC inhibited C. sakazakii survival and replication in human macrophages. We also observed that TC reduced the ability of C. sakazakii to cause cell death in rat intestinal cells, by inhibiting nitric oxide production. Results from gene expression studies revealed that TC significantly downregulated the virulence genes critical for motility, host tissue adhesion and invasion, macrophage survival, and LPS (Lipopolysaccharide) synthesis in C. sakazakii. The efficacy of TC in attenuating these major virulence factors in C. sakazakii underscores its potential use in the prevention and/or control of infection caused by this pathogen.

Functional and clinical relevance of VLA-4 (CD49d/CD29) in ibrutinib-treated chronic lymphocytic leukemia.

PubMed

Tissino, Erika; Benedetti, Dania; Herman, Sarah E M; Ten Hacken, Elisa; Ahn, Inhye E; Chaffee, Kari G; Rossi, Francesca Maria; Dal Bo, Michele; Bulian, Pietro; Bomben, Riccardo; Bayer, Elisabeth; Härzschel, Andrea; Gutjahr, Julia Christine; Postorino, Massimiliano; Santinelli, Enrico; Ayed, Ayed; Zaja, Francesco; Chiarenza, Annalisa; Pozzato, Gabriele; Chigaev, Alexandre; Sklar, Larry A; Burger, Jan A; Ferrajoli, Alessandra; Shanafelt, Tait D; Wiestner, Adrian; Del Poeta, Giovanni; Hartmann, Tanja Nicole; Gattei, Valter; Zucchetto, Antonella

2018-02-05

The Bruton's tyrosine kinase (BTK) inhibitor ibrutinib, which antagonizes B cell receptor (BCR) signals, demonstrates remarkable clinical activity in chronic lymphocytic leukemia (CLL). The lymphocytosis experienced by most patients under ibrutinib has previously been attributed to inhibition of BTK-dependent integrin and chemokine cues operating to retain the tumor cells in nodal compartments. Here, we show that the VLA-4 integrin, as expressed by CD49d-positive CLL, can be inside-out activated upon BCR triggering, thus reinforcing the adhesive capacities of CLL cells. In vitro and in vivo ibrutinib treatment, although reducing the constitutive VLA-4 activation and cell adhesion, can be overcome by exogenous BCR triggering in a BTK-independent manner involving PI3K. Clinically, in three independent ibrutinib-treated CLL cohorts, CD49d expression identifies cases with reduced lymphocytosis and inferior nodal response and behaves as independent predictor of shorter progression-free survival, suggesting the retention of CD49d-expressing CLL cells in tissue sites via activated VLA-4. Evaluation of CD49d expression should be incorporated in the characterization of CLL undergoing therapy with BCR inhibitors. © 2018 Tissino et al.

Functional and clinical relevance of VLA-4 (CD49d/CD29) in ibrutinib-treated chronic lymphocytic leukemia

PubMed Central

Tissino, Erika; Benedetti, Dania; Herman, Sarah E.M.; ten Hacken, Elisa; Rossi, Francesca Maria; Dal Bo, Michele; Bulian, Pietro; Bomben, Riccardo; Bayer, Elisabeth; Härzschel, Andrea; Gutjahr, Julia Christine; Postorino, Massimiliano; Santinelli, Enrico; Zaja, Francesco; Pozzato, Gabriele; Chigaev, Alexandre; Sklar, Larry A.; Burger, Jan A.; Ferrajoli, Alessandra; Shanafelt, Tait D.; Wiestner, Adrian; Del Poeta, Giovanni; Hartmann, Tanja Nicole

2018-01-01

The Bruton’s tyrosine kinase (BTK) inhibitor ibrutinib, which antagonizes B cell receptor (BCR) signals, demonstrates remarkable clinical activity in chronic lymphocytic leukemia (CLL). The lymphocytosis experienced by most patients under ibrutinib has previously been attributed to inhibition of BTK-dependent integrin and chemokine cues operating to retain the tumor cells in nodal compartments. Here, we show that the VLA-4 integrin, as expressed by CD49d-positive CLL, can be inside-out activated upon BCR triggering, thus reinforcing the adhesive capacities of CLL cells. In vitro and in vivo ibrutinib treatment, although reducing the constitutive VLA-4 activation and cell adhesion, can be overcome by exogenous BCR triggering in a BTK-independent manner involving PI3K. Clinically, in three independent ibrutinib-treated CLL cohorts, CD49d expression identifies cases with reduced lymphocytosis and inferior nodal response and behaves as independent predictor of shorter progression-free survival, suggesting the retention of CD49d-expressing CLL cells in tissue sites via activated VLA-4. Evaluation of CD49d expression should be incorporated in the characterization of CLL undergoing therapy with BCR inhibitors. PMID:29301866

Mechanisms Underlying the Anti-Tumoral Effects of Citrus bergamia Juice

PubMed Central

Delle Monache, Simona; Sanità, Patrizia; Trapasso, Elena; Ursino, Maria Rita; Dugo, Paola; Russo, Marina; Ferlazzo, Nadia; Calapai, Gioacchino; Angelucci, Adriano; Navarra, Michele

2013-01-01

Based on the growing deal of data concerning the biological activity of flavonoid-rich natural products, the aim of the present study was to explore in vitro the potential anti-tumoral activity of Citrus Bergamia (bergamot) juice (BJ), determining its molecular interaction with cancer cells. Here we show that BJ reduced growth rate of different cancer cell lines, with the maximal growth inhibition observed in neuroblastoma cells (SH-SY5Y) after 72 hs of exposure to 5% BJ. The SH-SY5Y antiproliferative effect elicited by BJ was not due to a cytotoxic action and it did not induce apoptosis. Instead, BJ stimulated the arrest in the G1 phase of cell cycle and determined a modification in cellular morphology, causing a marked increase of detached cells. The inhibition of adhesive capacity on different physiologic substrates and on endothelial cells monolayer were correlated with an impairment of actin filaments, a reduction in the expression of the active form of focal adhesion kinase (FAK) that in turn caused inhibition of cell migration. In parallel, BJ seemed to hinder the association between the neural cell adhesion molecule (NCAM) and FAK. Our data suggest a mechanisms through which BJ can inhibit important molecular pathways related to cancer-associated aggressive phenotype and offer new suggestions for further studies on the role of BJ in cancer treatment. PMID:23613861

Leupaxin stimulates adhesion and migration of prostate cancer cells through modulation of the phosphorylation status of the actin-binding protein caldesmon

PubMed Central

Schmidt, Thomas; Bremmer, Felix; Burfeind, Peter; Kaulfuß, Silke

2015-01-01

The focal adhesion protein leupaxin (LPXN) is overexpressed in a subset of prostate cancers (PCa) and is involved in the progression of PCa. In the present study, we analyzed the LPXN-mediated adhesive and cytoskeletal changes during PCa progression. We identified an interaction between the actin-binding protein caldesmon (CaD) and LPXN and this interaction is increased during PCa cell migration. Furthermore, knockdown of LPXN did not affect CaD expression but reduced CaD phosphorylation. This is known to destabilize the affinity of CaD to F-actin, leading to dynamic cell structures that enable cell motility. Thus, downregulation of CaD increased migration and invasion of PCa cells. To identify the kinase responsible for the LPXN-mediated phosphorylation of CaD, we used data from an antibody array, which showed decreased expression of TGF-beta-activated kinase 1 (TAK1) after LPXN knockdown in PC-3 PCa cells. Subsequent analyses of the downstream kinases revealed the extracellular signal-regulated kinase (ERK) as an interaction partner of LPXN that facilitates CaD phosphorylation during LPXN-mediated PCa cell migration. In conclusion, we demonstrate that LPXN directly influences cytoskeletal dynamics via interaction with the actin-binding protein CaD and regulates CaD phosphorylation by recruiting ERK to highly dynamic structures within PCa cells. PMID:26079947

The molecular mechanism of mediation of adsorbed serum proteins to endothelial cells adhesion and growth on biomaterials.

PubMed

Yang, Dayun; Lü, Xiaoying; Hong, Ying; Xi, Tingfei; Zhang, Deyuan

2013-07-01

To explore molecular mechanism of mediation of adsorbed proteins to cell adhesion and growth on biomaterials, this study examined endothelial cell adhesion, morphology and viability on bare and titanium nitride (TiN) coated nickel titanium (NiTi) alloys and chitosan film firstly, and then identified the type and amount of serum proteins adsorbed on the three surfaces by proteomic technology. Subsequently, the mediation role of the identified proteins to cell adhesion and growth was investigated with bioinformatics analyses, and further confirmed by a series of cellular and molecular biological experiments. Results showed that the type and amount of adsorbed serum proteins associated with cell adhesion and growth was obviously higher on the alloys than on the chitosan film, and these proteins mediated endothelial cell adhesion and growth on the alloys via four ways. First, proteins such as adiponectin in the adsorbed protein layer bound with cell surface receptors to generate signal transduction, which activated cell surface integrins through increasing intracellular calcium level. Another way, thrombospondin 1 in the adsorbed protein layer promoted TGF-β signaling pathway activation and enhanced integrins expression. The third, RGD sequence containing proteins such as fibronectin 1, vitronectin and thrombospondin 1 in the adsorbed protein layer bound with activated integrins to activate focal adhesion pathway, increased focal adhesion formation and actin cytoskeleton organization and mediated cell adhesion and spreading. In addition, the activated focal adhesion pathway promoted the expression of cell growth related genes and resulted in cell proliferation. The fourth route, coagulation factor II (F2) and fibronectin 1 in the adsorbed protein layer bound with cell surface F2 receptor and integrin, activated regulation of actin cytoskeleton pathway and regulated actin cytoskeleton organization. Copyright © 2013 Elsevier Ltd. All rights reserved.

Design rules for biomolecular adhesion: lessons from force measurements.

PubMed

Leckband, Deborah

2010-01-01

Cell adhesion to matrix, other cells, or pathogens plays a pivotal role in many processes in biomolecular engineering. Early macroscopic methods of quantifying adhesion led to the development of quantitative models of cell adhesion and migration. The more recent use of sensitive probes to quantify the forces that alter or manipulate adhesion proteins has revealed much greater functional diversity than was apparent from population average measurements of cell adhesion. This review highlights theoretical and experimental methods that identified force-dependent molecular properties that are central to the biological activity of adhesion proteins. Experimental and theoretical methods emphasized in this review include the surface force apparatus, atomic force microscopy, and vesicle-based probes. Specific examples given illustrate how these tools have revealed unique properties of adhesion proteins and their structural origins.

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

PubMed

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

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

Laser Surface Microstructuring of Biocompatible Materials Using a Microlens Array and the Talbot Effect: Evaluation of the Cell Adhesion.

PubMed

Aymerich, María; Nieto, Daniel; Álvarez, Ezequiel; Flores-Arias, María T

2017-02-22

A laser based technique for microstructuring titanium and tantalum substrates using the Talbot effect and an array of microlenses is presented. By using this hybrid technique; we are able to generate different patterns and geometries on the top surfaces of the biomaterials. The Talbot effect allows us to rapidly make microstructuring, solving the common problems of using microlenses for multipatterning; where the material expelled during the ablation of biomaterials damages the microlens. The Talbot effect permits us to increase the working distance and reduce the period of the patterns. We also demonstrate that the geometries and patterns act as anchor points for cells; affecting the cell adhesion to the metallic substrates and guiding how they spread over the material.

Laser Surface Microstructuring of Biocompatible Materials Using a Microlens Array and the Talbot Effect: Evaluation of the Cell Adhesion

PubMed Central

Aymerich, María; Nieto, Daniel; Álvarez, Ezequiel; Flores-Arias, María T.

2017-01-01

A laser based technique for microstructuring titanium and tantalum substrates using the Talbot effect and an array of microlenses is presented. By using this hybrid technique; we are able to generate different patterns and geometries on the top surfaces of the biomaterials. The Talbot effect allows us to rapidly make microstructuring, solving the common problems of using microlenses for multipatterning; where the material expelled during the ablation of biomaterials damages the microlens. The Talbot effect permits us to increase the working distance and reduce the period of the patterns. We also demonstrate that the geometries and patterns act as anchor points for cells; affecting the cell adhesion to the metallic substrates and guiding how they spread over the material. PMID:28772574

Atomic Force Microscopy Mechanical Mapping of Micropatterned Cells Shows Adhesion Geometry-Dependent Mechanical Response on Local and Global Scales

PubMed Central

Rigato, Annafrancesca; Rico, Felix; Eghiaian, Frédéric; Piel, Mathieu; Scheuring, Simon

2015-01-01

In multicellular organisms cell shape and organization are dictated by cell-cell or cell-extracellular matrix adhesion interactions. Adhesion complexes crosstalk with the cytoskeleton enabling cells to sense their mechanical environment. Unfortunately, most of cell biology studies, and cell mechanics studies in particular, are conducted on cultured cells adhering to a hard, homogeneous and unconstrained substrate with non-specific adhesion sites – thus far from physiological and reproducible conditions. Here, we grew cells on three different fibronectin patterns with identical overall dimensions but different geometries (▽, T and Y), and investigated their topography and mechanics by atomic force microscopy (AFM). The obtained mechanical maps were reproducible for cells grown on patterns of the same geometry, revealing pattern-specific subcellular differences. We found that local Young’s moduli variations are related to the cell adhesion geometry. Additionally, we detected local changes of cell mechanical properties induced by cytoskeletal drugs. We thus provide a method to quantitatively and systematically investigate cell mechanics and their variations, and present further evidence for a tight relation between cell adhesion and mechanics. PMID:26013956

Atomic Force Microscopy Mechanical Mapping of Micropatterned Cells Shows Adhesion Geometry-Dependent Mechanical Response on Local and Global Scales.

PubMed

Rigato, Annafrancesca; Rico, Felix; Eghiaian, Frédéric; Piel, Mathieu; Scheuring, Simon

2015-06-23

In multicellular organisms, cell shape and organization are dictated by cell-cell or cell-extracellular matrix adhesion interactions. Adhesion complexes crosstalk with the cytoskeleton enabling cells to sense their mechanical environment. Unfortunately, most of cell biology studies, and cell mechanics studies in particular, are conducted on cultured cells adhering to a hard, homogeneous, and unconstrained substrate with nonspecific adhesion sites, thus far from physiological and reproducible conditions. Here, we grew cells on three different fibronectin patterns with identical overall dimensions but different geometries (▽, T, and Y), and investigated their topography and mechanics by atomic force microscopy (AFM). The obtained mechanical maps were reproducible for cells grown on patterns of the same geometry, revealing pattern-specific subcellular differences. We found that local Young's moduli variations are related to the cell adhesion geometry. Additionally, we detected local changes of cell mechanical properties induced by cytoskeletal drugs. We thus provide a method to quantitatively and systematically investigate cell mechanics and their variations, and present further evidence for a tight relation between cell adhesion and mechanics.

Down-regulation of POLYGALACTURONASE1 alters firmness, tensile strength and water loss in apple (Malus x domestica) fruit.

PubMed

Atkinson, Ross G; Sutherland, Paul W; Johnston, Sarah L; Gunaseelan, Kularajathevan; Hallett, Ian C; Mitra, Deepali; Brummell, David A; Schröder, Roswitha; Johnston, Jason W; Schaffer, Robert J

2012-08-02

While there is now a significant body of research correlating apple (Malus x domestica) fruit softening with the cell wall hydrolase ENDO-POLYGALACTURONASE1 (PG1), there is currently little knowledge of its physiological effects in planta. This study examined the effect of down regulation of PG1 expression in 'Royal Gala' apples, a cultivar that typically has high levels of PG1, and softens during fruit ripening. PG1-suppressed 'Royal Gala' apples harvested from multiple seasons were firmer than controls after ripening, and intercellular adhesion was higher. Cell wall analyses indicated changes in yield and composition of pectin, and a higher molecular weight distribution of CDTA-soluble pectin. Structural analyses revealed more ruptured cells and free juice in pulled apart sections, suggesting improved integrity of intercellular connections and consequent cell rupture due to failure of the primary cell walls under stress. PG1-suppressed lines also had reduced expansion of cells in the hypodermis of ripe apples, resulting in more densely packed cells in this layer. This change in morphology appears to be linked with reduced transpirational water loss in the fruit. These findings confirm PG1's role in apple fruit softening and suggests that this is achieved in part by reducing cellular adhesion. This is consistent with previous studies carried out in strawberry but not with those performed in tomato. In apple PG1 also appears to influence other fruit texture characters such as juiciness and water loss.

Pyrrole-hyaluronic acid conjugates for decreasing cell binding to metals and conducting polymers

PubMed Central

Lee, Jae Young; Schmidt, Christine E.

2010-01-01

Surface modification of electrically conductive biomaterials has been studied to improve biocompatibility for a number of applications, such as implantable sensors and microelectrode arrays. In this study, we electrochemically coated electrodes with biocompatible and non-cell adhesive hyaluronic acid (HA) to reduce cellular adhesion for potential use in neural prostheses. To this end, pyrrole-conjugated hyaluronic acid (PyHA) was synthesized and employed for electrochemical coating of platinum, indium-tin-oxide, and polystyrene sulfonate-doped polypyrrole electrodes. This PyHA conjugate consists of (1) a pyrrole moiety that allows the compound to be electrochemically deposited onto a conductive substrate and (2) non-adhesive HA to minimize cell adhesion and to potentially decrease inflammatory tissue responses. Our characterization results showed the presence of a hydrophilic p(PyHA) layer on the modified electrode, and impedance measurements revealed impedance that was statistically the same as the unmodified electrode. We found that the p(PyHA)-coated electrodes minimized adhesion and migration of fibroblasts and astrocytes for a minimum of up to 3 months. Also, the coating was stable in physiological solution for 3 months and also stable against enzymatic degradation by hyaluronidase. These studies suggest that this p(PyHA)-coating has the potential to be used to mask conducting electrodes from adverse glial responses that occur upon implantation. In addition, electrochemical coating with PyHA can be potentially extended for the surface modification of other metallic and conducting substances such as stents and biosensors. PMID:20558330

Emergence of collective propulsion through cell-cell adhesion.

PubMed

Matsushita, Katsuyoshi

2018-04-01

The mechanisms driving the collective movement of cells remain poorly understood. To contribute toward resolving this mystery, a model was formulated to theoretically explore the possible functions of polarized cell-cell adhesion in collective cell migration. The model consists of an amoeba cell with polarized cell-cell adhesion, which is controlled by positive feedback with cell motion. This model cell has no persistent propulsion and therefore exhibits a simple random walk when in isolation. However, at high density, these cells acquire collective propulsion and form ordered movement. This result suggests that cell-cell adhesion has a potential function, which induces collective propulsion with persistence.

Emergence of collective propulsion through cell-cell adhesion

NASA Astrophysics Data System (ADS)

Matsushita, Katsuyoshi

2018-04-01

The mechanisms driving the collective movement of cells remain poorly understood. To contribute toward resolving this mystery, a model was formulated to theoretically explore the possible functions of polarized cell-cell adhesion in collective cell migration. The model consists of an amoeba cell with polarized cell-cell adhesion, which is controlled by positive feedback with cell motion. This model cell has no persistent propulsion and therefore exhibits a simple random walk when in isolation. However, at high density, these cells acquire collective propulsion and form ordered movement. This result suggests that cell-cell adhesion has a potential function, which induces collective propulsion with persistence.

Infection of human intestinal epithelial cells with invasive bacteria upregulates apical intercellular adhesion molecule-1 (ICAM)-1) expression and neutrophil adhesion.

PubMed Central

Huang, G T; Eckmann, L; Savidge, T C; Kagnoff, M F

1996-01-01

The acute host response to gastrointestinal infection with invasive bacteria is characterized by an accumulation of neutrophils in the lamina propria, and neutrophil transmigration to the luminal side of the crypts. Intestinal epithelial cells play an important role in the recruitment of inflammatory cells to the site of infection through the secretion of chemokines. However, little is known regarding the expression, by epithelial cells, of molecules that are involved in interactions between the epithelium and neutrophils following bacterial invasion. We report herein that expression of ICAM-1 on human colon epithelial cell lines, and on human enterocytes in an in vivo model system, is upregulated following infection with invasive bacteria. Increased ICAM-1 expression in the early period (4-9 h) after infection appeared to result mainly from a direct interaction between invaded bacteria and host epithelial cells since it co-localized to cells invaded by bacteria, and the release of soluble factors by epithelial cells played only a minor role in mediating increased ICAM-1 expression. Furthermore, ICAM-1 was expressed on the apical side of polarized intestinal epithelial cells, and increased expression was accompanied by increased neutrophil adhesion to these cells. ICAM-1 expression by intestinal epithelial cells following infection with invasive bacteria may function to maintain neutrophils that have transmigrated through the epithelium in close contact with the intestinal epithelium, thereby reducing further invasion of the mucosa by invading pathogens. PMID:8755670

Surfactant Functionalization Induces Robust, Differential Adhesion of Tumor Cells and Blood Cells to Charged Nanotube-Coated Biomaterials Under Flow

PubMed Central

Mitchell, Michael J.; Castellanos, Carlos A.; King, Michael R.

2015-01-01

The metastatic spread of cancer cells from the primary tumor to distant sites leads to a poor prognosis in cancers originating from multiple organs. Increasing evidence has linked selectin-based adhesion between circulating tumor cells (CTCs) and endothelial cells of the microvasculature to metastatic dissemination, in a manner similar to leukocyte adhesion during inflammation. Functionalized biomaterial surfaces hold promise as a diagnostic tool to separate CTCs and potentially treat metastasis, utilizing antibody and selectin-mediated interactions for cell capture under flow. However, capture at high purity levels is challenged by the fact that CTCs and leukocytes both possess selectin ligands. Here, a straightforward technique to functionalize and alter the charge of naturally occurring halloysite nanotubes using surfactants is reported to induce robust, differential adhesion of tumor cells and blood cells to nanotube-coated surfaces under flow. Negatively charged sodium dodecanoate-functionalized nanotubes simultaneously enhanced tumor cell capture while negating leukocyte adhesion, both in the presence and absence of adhesion proteins, and can be utilized to isolate circulating tumor cells regardless of biomarker expression. Conversely, diminishing nanotube charge via functionalization with decyltrimethylammonium bromide both abolished tumor cell capture while promoting leukocyte adhesion. PMID:25934290

Reinjury risk of nano-calcium oxalate monohydrate and calcium oxalate dihydrate crystals on injured renal epithelial cells: aggravation of crystal adhesion and aggregation

PubMed Central

Gan, Qiong-Zhi; Sun, Xin-Yuan; Bhadja, Poonam; Yao, Xiu-Qiong; Ouyang, Jian-Ming

2016-01-01

Background Renal epithelial cell injury facilitates crystal adhesion to cell surface and serves as a key step in renal stone formation. However, the effects of cell injury on the adhesion of nano-calcium oxalate crystals and the nano-crystal-induced reinjury risk of injured cells remain unclear. Methods African green monkey renal epithelial (Vero) cells were injured with H2O2 to establish a cell injury model. Cell viability, superoxide dismutase (SOD) activity, malonaldehyde (MDA) content, propidium iodide staining, hematoxylin–eosin staining, reactive oxygen species production, and mitochondrial membrane potential (Δψm) were determined to examine cell injury during adhesion. Changes in the surface structure of H2O2-injured cells were assessed through atomic force microscopy. The altered expression of hyaluronan during adhesion was examined through laser scanning confocal microscopy. The adhesion of nano-calcium oxalate monohydrate (COM) and calcium oxalate dihydrate (COD) crystals to Vero cells was observed through scanning electron microscopy. Nano-COM and COD binding was quantitatively determined through inductively coupled plasma emission spectrometry. Results The expression of hyaluronan on the cell surface was increased during wound healing because of Vero cell injury. The structure and function of the cell membrane were also altered by cell injury; thus, nano-crystal adhesion occurred. The ability of nano-COM to adhere to the injured Vero cells was higher than that of nano-COD crystals. The cell viability, SOD activity, and Δψm decreased when nano-crystals attached to the cell surface. By contrast, the MDA content, reactive oxygen species production, and cell death rate increased. Conclusion Cell injury contributes to crystal adhesion to Vero cell surface. The attached nano-COM and COD crystals can aggravate Vero cell injury. As a consequence, crystal adhesion and aggregation are enhanced. These findings provide further insights into kidney stone formation. PMID:27382277

Photocrosslinkable Gelatin/Tropoelastin Hydrogel Adhesives for Peripheral Nerve Repair.

PubMed

Soucy, Jonathan R; Shirzaei Sani, Ehsan; Portillo Lara, Roberto; Diaz, David; Dias, Felipe; Weiss, Anthony S; Koppes, Abigail N; Koppes, Ryan A; Annabi, Nasim

2018-05-09

Suturing peripheral nerve transections is the predominant therapeutic strategy for nerve repair. However, the use of sutures leads to scar tissue formation, hinders nerve regeneration, and prevents functional recovery. Fibrin-based adhesives have been widely used for nerve reconstruction, but their limited adhesive and mechanical strength and inability to promote nerve regeneration hamper their utility as a stand-alone intervention. To overcome these challenges, we engineered composite hydrogels that are neurosupportive and possess strong tissue adhesion. These composites were synthesized by photocrosslinking two naturally derived polymers, gelatin-methacryloyl (GelMA) and methacryloyl-substituted tropoelastin (MeTro). The engineered materials exhibited tunable mechanical properties by varying the GelMA/MeTro ratio. In addition, GelMA/MeTro hydrogels exhibited 15-fold higher adhesive strength to nerve tissue ex vivo compared to fibrin control. Furthermore, the composites were shown to support Schwann cell (SC) viability and proliferation, as well as neurite extension and glial cell participation in vitro, which are essential cellular components for nerve regeneration. Finally, subcutaneously implanted GelMA/MeTro hydrogels exhibited slower degradation in vivo compared with pure GelMA, indicating its potential to support the growth of slowly regenerating nerves. Thus, GelMA/MeTro composites may be used as clinically relevant biomaterials to regenerate nerves and reduce the need for microsurgical suturing during nerve reconstruction.

Black Currant (Ribes nigrum L.) and Bilberry (Vaccinium myrtillus L.) Fruit Juices Inhibit Adhesion of Asaia spp.

PubMed Central

2016-01-01

The aim of the study was to evaluate the activity of high-polyphenolic black currant (Ribes nigrum L.) and bilberry (Vaccinium myrtillus L.) juices against bacterial strains Asaia lannensis and Asaia bogorensis isolated as spoilage of commercial soft drinks. The composition of fruit juices was evaluated using chromatographic techniques HPLC and LC-MS. The adhesion to glass, polystyrene, and polyethylene terephthalate in two different culture media was evaluated by luminometry and the plate count method. The major anthocyanins in the V. myrtillus were petunidin-3-glucoside, malvidin-3-glucoside, cyanidin-3-glucoside, and delphinidin-3-glucoside, while in R. nigrum delphinidin-3-rutinoside and cyanidin-3-rutinoside were detected. The LC-MS analysis showed presence of anthocyanins (delphinidin, cyanidin, petunidin, and malvidin derivatives), phenolic acids (chlorogenic and neochlorogenic acids), flavonols (quercetin-3-glucoside, quercetin-3-rutinoside), and flavanols (procyanidin B2 and procyanidin type A2). Additionally, in the bilberry juice A type procyanidin trimer was detected. The adhesion of Asaia spp. cells depended on the type of medium, carbon sources, and the type of abiotic surfaces. We noted that the adhesion was significantly stronger in minimal medium containing sucrose. The addition of bilberry and black currant juices notably reduced bacterial growth as well as cell adhesion to polyethylene terephthalate surfaces. PMID:27747228