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Sample records for integrin lymphocyte function-associated

  1. beta1 integrins are not required for the maintenance of lymphocytes within intestinal epithelia

    DEFF Research Database (Denmark)

    Marsal, Jan; Brakebusch, Cord; Bungartz, Gerd

    2005-01-01

    beta(1) integrins are thought to play a central role in maintaining lymphocytes within mucosal epithelia via their interactions with extracellular matrix proteins and subepithelial cellular components within and underlying the basement membrane. In the current study type a (CD8alphabetaTCRalphabe......beta(1) integrins are thought to play a central role in maintaining lymphocytes within mucosal epithelia via their interactions with extracellular matrix proteins and subepithelial cellular components within and underlying the basement membrane. In the current study type a (CD8alphabeta......TCRalphabeta) and type b (CD8alphaalphaTCRgammadelta and CD8alphaalphaTCRalphabeta) intraepithelial lymphocyte (IEL) subsets within the mouse small intestine were found to express functional beta(1) integrin and the beta(1) integrin alpha chain partners alpha(1), alpha(2), and alpha(4). Using inducible beta(1) integrin......-knockout bone marrow-chimeric mice we demonstrate that IEL expression of alpha(1) and alpha(2) but not alpha(4) is dependent on expression of the beta(1) chain. Importantly, deletion of the beta(1) chain in IEL did not alter the number or composition of lymphocytes within the intestinal epithelium. Thus, while...

  2. Lymphocyte integrin expression differences between SIRS and sepsis patients.

    Science.gov (United States)

    Heffernan, D S; Monaghan, S F; Ayala, Alfred

    2017-11-01

    Systemic Inflammatory Response Syndrome (SIRS) and sepsis remain leading causes of death. Despite many similarities, the two entities are very distinct clinically and immunologically. T-Lymphocytes play a key pivotal role in the pathogenesis and ultimately outcome following both SIRS and sepsis. Integrins are essential in the trafficking and migration of lymphocytes. They also serve vital roles in efficient wound healing and clearance of infections. Here, we investigate whether integrin expression, specifically β1 (CD29) and β2 (CD18), are disrupted in SIRS and sepsis, and assess differences in integrin expression between these two critically ill clinical categories. T-Lymphocytes were isolated from whole blood collected from ICU patients exhibiting SIRS or sepsis. Samples were analyzed for CD18 (β2) and CD29 (β1) on CD3 + T cells through flow cytometry. Septic patients were stratified into either exclusively abdominal or non-abdominal sources of sepsis. CD18 was almost ubiquitously expressed on CD3 + T cells irrespective of clinical condition. However, CD29 (β1 integrin) was lowest in SIRS patients (20.4% of CD3 + T cells) when compared with either septic patients (35.5%) or healthy volunteers (54.1%). Furthermore, there was evidence of compartmentalization in septic patients, where abdominal sources had a greater percentage of CD3 + CD29 + T cells (41.7%) when compared with those with non-abdominal sources (29.5%). Distinct differences in T-cell integrin expression exists between patients in SIRS versus sepsis, as well as relative to the source of sepsis. Further work is needed to understand cause and effect relative to the progression from SIRS into sepsis.

  3. Disintegrins: integrin selective ligands which activate integrin-coupled signaling and modulate leukocyte functions

    Directory of Open Access Journals (Sweden)

    Barja-Fidalgo C.

    2005-01-01

    Full Text Available Extracellular matrix proteins and cell adhesion receptors (integrins play essential roles in the regulation of cell adhesion and migration. Interactions of integrins with the extracellular matrix proteins lead to phosphorylation of several intracellular proteins such as focal adhesion kinase, activating different signaling pathways responsible for the regulation of a variety of cell functions, including cytoskeleton mobilization. Once leukocytes are guided to sites of infection, inflammation, or antigen presentation, integrins can participate in the initiation, maintenance, or termination of the immune and inflammatory responses. The modulation of neutrophil activation through integrin-mediated pathways is important in the homeostatic control of the resolution of inflammatory states. In addition, during recirculation, T lymphocyte movement through distinct microenvironments is mediated by integrins, which are critical for cell cycle, differentiation and gene expression. Disintegrins are a family of low-molecular weight, cysteine-rich peptides first identified in snake venom, usually containing an RGD (Arg-Gly-Asp motif, which confers the ability to selectively bind to integrins, inhibiting integrin-related functions in different cell systems. In this review we show that, depending on the cell type and the microenvironment, disintegrins are able to antagonize the effects of integrins or to act agonistically by activating integrin-mediated signaling. Disintegrins have proven useful as tools to improve the understanding of the molecular events regulated by integrin signaling in leukocytes and prototypes in order to design therapies able to interfere with integrin-mediated effects.

  4. Retinoids induce integrin-independent lymphocyte adhesion through RAR-α nuclear receptor activity

    International Nuclear Information System (INIS)

    Whelan, Jarrett T.; Wang, Lei; Chen, Jianming; Metts, Meagan E.; Nasser, Taj A.; McGoldrick, Liam J.; Bridges, Lance C.

    2014-01-01

    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 X 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) 2 D 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

  5. Retinoids induce integrin-independent lymphocyte adhesion through RAR-α nuclear receptor activity

    Energy Technology Data Exchange (ETDEWEB)

    Whelan, Jarrett T.; Wang, Lei; Chen, Jianming; Metts, Meagan E.; Nasser, Taj A.; McGoldrick, Liam J. [Department of Biochemistry and Molecular Biology, The Brody School of Medicine at East Carolina University, Greenville, NC 27834 (United States); Bridges, Lance C., E-mail: bridgesl@ecu.edu [Department of Biochemistry and Molecular Biology, The Brody School of Medicine at East Carolina University, Greenville, NC 27834 (United States); East Carolina Diabetes and Obesity Institute, The Brody School of Medicine at East Carolina University, Greenville, NC 27834 (United States)

    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 X 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.

  6. The adaptor molecule RIAM integrates signaling events critical for integrin-mediated control of immune function and cancer progression.

    Science.gov (United States)

    Patsoukis, Nikolaos; Bardhan, Kankana; Weaver, Jessica D; Sari, Duygu; Torres-Gomez, Alvaro; Li, Lequn; Strauss, Laura; Lafuente, Esther M; Boussiotis, Vassiliki A

    2017-08-22

    Lymphocyte activation requires adhesion to antigen-presenting cells. This is a critical event linking innate and adaptive immunity. Lymphocyte adhesion is accomplished through LFA-1, which must be activated by a process referred to as inside-out integrin signaling. Among the few signaling molecules that have been implicated in inside-out integrin activation in hematopoietic cells are the small guanosine triphosphatase (GTPase) Rap1 and its downstream effector Rap1-interacting molecule (RIAM), a multidomain protein that defined the Mig10-RIAM-lamellipodin (MRL) class of adaptor molecules. Through its various domains, RIAM is a critical node of signal integration for activation of T cells, recruits monomeric and polymerized actin to drive actin remodeling and cytoskeletal reorganization, and promotes inside-out integrin signaling in T cells. As a regulator of inside-out integrin activation, RIAM affects multiple functions of innate and adaptive immunity. The effects of RIAM on cytoskeletal reorganization and integrin activation have implications in cell migration and trafficking of cancer cells. We provide an overview of the structure and interactions of RIAM, and we discuss the implications of RIAM functions in innate and adaptive immunity and cancer. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

  7. An integrin alpha4beta7•IgG heterodimeric chimera binds to MAdCAM-1 on high endothelial venules in gut-associated lymphoid tissue.

    Science.gov (United States)

    Hoshino, Hitomi; Kobayashi, Motohiro; Mitoma, Junya; Sato, Yoshiko; Fukuda, Minoru; Nakayama, Jun

    2011-06-01

    Lymphocyte homing is regulated by a multistep process mediated by sequential adhesive interactions between circulating lymphocytes and high endothelial venules (HEVs). In gut-associated lymphoid tissue (GALT), the initial interactive step, "tethering and rolling," is partly mediated by integrin α4β7 expressed on GALT-homing lymphocytes and its ligand MAdCAM-1, which is exclusively expressed on HEVs in GALT. To probe functional MAdCAM-1 in tissue sections, we developed a soluble integrin α4β7 heterodimeric IgG chimera by joining the extracellular region of mouse integrin α4 and β7 subunits to a human IgG Fc domain. Western blot analysis revealed that co-transfection of HEK 293T cells with expression vectors encoding integrin α4•IgG and β7•IgG results in the formation of α4β7•IgG heterodimeric chimeras. This complex preferentially binds to CHO cells expressing MAdCAM-1 and, to a lesser extent, to cells expressing VCAM-1, but not to cells expressing ICAM-1. Moreover, α4β7•IgG specifically binds to HEVs in GALT in situ in a divalent cation-dependent fashion and inhibits lymphocyte binding to HEVs in GALT. These findings indicate that α4β7•IgG can be used as a probe for functional MAdCAM-1 expressed on HEVs in GALT and could potentially serve as an anti-inflammatory drug inhibiting GALT-specific lymphocyte migration.

  8. ADAM disintegrin-like domain recognition by the lymphocyte integrins α4β1 and α4β7

    Science.gov (United States)

    Bridges, Lance C.; Sheppard, Dean; Bowditch, Ron D.

    2004-01-01

    The ADAM (a disintegrin and metalloprotease) family of proteins possess both proteolytic and adhesive domains. We have established previously that the disintegrin domain of ADAM28, an ADAM expressed by human lymphocytes, is recognized by the integrin α4β1. The present study characterizes the integrin binding properties of the disintegrin-like domains of human ADAM7, ADAM28 and ADAM33 with the integrins α4β1, α4β7 and α9β1. Cell-adhesion assays demonstrated that, similar to ADAM28, the ADAM7 disintegrin domain supported α4β1-dependent Jurkat cell adhesion, whereas the ADAM33 disintegrin domain did not. The lymphocyte integrin α4β7 was also found to recognize both disintegrin domains of ADAM7 and ADAM28, but not of ADAM33. This is the first demonstration that mammalian disintegrins are capable of interacting with α4β7. All three disintegrin domains supported α9β1-dependent cell adhesion. Recognition by both α4β1 and α4β7 of ADAM7 and ADAM28 was activation-dependent, requiring either the presence of Mn2+ or an activating monoclonal antibody for cell attachment. Charge-to-alanine mutagenesis experiments revealed that the same residues within an individual ADAM disintegrin domain function in recognizing multiple integrins. However, the residues within a specific region of each ADAM disintegrin-like domain required for integrin binding were distinct. These results establish that ADAM7 and ADAM28 are recognized by the leucocyte integrins α4β1, α4β7 and α9β1. ADAM33 exclusively supported only α9β1-dependent adhesion. PMID:15504110

  9. Transmission of integrin β7 transmembrane domain topology enables gut lymphoid tissue development.

    Science.gov (United States)

    Sun, Hao; Lagarrigue, Frederic; Gingras, Alexandre R; Fan, Zhichao; Ley, Klaus; Ginsberg, Mark H

    2018-04-02

    Integrin activation regulates adhesion, extracellular matrix assembly, and cell migration, thereby playing an indispensable role in development and in many pathological processes. A proline mutation in the central integrin β3 transmembrane domain (TMD) creates a flexible kink that uncouples the topology of the inner half of the TMD from the outer half. In this study, using leukocyte integrin α4β7, which enables development of gut-associated lymphoid tissue (GALT), we examined the biological effect of such a proline mutation and report that it impairs agonist-induced talin-mediated activation of integrin α4β7, thereby inhibiting rolling lymphocyte arrest, a key step in transmigration. Furthermore, the α4β7(L721P) mutation blocks lymphocyte homing to and development of the GALT. These studies show that impairing the ability of an integrin β TMD to transmit talin-induced TMD topology inhibits agonist-induced physiological integrin activation and biological function in development. © 2018 Sun et al.

  10. ADAM disintegrin-like domain recognition by the lymphocyte integrins α4β1 and α4β7

    OpenAIRE

    Bridges, Lance C.; Sheppard, Dean; Bowditch, Ron D.

    2005-01-01

    The ADAM (a disintegrin and metalloprotease) family of proteins possess both proteolytic and adhesive domains. We have established previously that the disintegrin domain of ADAM28, an ADAM expressed by human lymphocytes, is recognized by the integrin α4β1. The present study characterizes the integrin binding properties of the disintegrin-like domains of human ADAM7, ADAM28 and ADAM33 with the integrins α4β1, α4β7 and α9β1. Cell-adhesion assays demonstrated that, similar to ADAM28, the ADAM7 d...

  11. T-cell-mediated immunity to lymphocytic choriomeningitis virus in beta2-integrin (CD18)- and ICAM-1 (CD54)-deficient mice

    DEFF Research Database (Denmark)

    Christensen, Jan Pravsgaard; Marker, O; Thomsen, Allan Randrup

    1996-01-01

    The T-cell response to lymphocytic choriomeningitis virus was studied in mice with deficient expression of beta2-integrins or ICAM-1. In such mice, the generation of virus-specific cytotoxic T lymphocytes was only slightly impaired and bystander activation was as extensive as that observed in wild-type...... mice. T-cell-mediated inflammation, assessed as primary footpad swelling and susceptibility to intracerebral infection, was slightly compromised only in beta2-integrin-deficient mice. However, adoptive immunization of mutant mice soon after local infection did reveal a reduced capacity to support...... the inflammatory reaction, indicating that under conditions of more limited immune activation both molecules do play a role in formation of the inflammatory exudate. Finally, virus control was found to be somewhat impaired in both mutant strains. In conclusion, our results indicate that although LFA-1-ICAM-1...

  12. Application of encoded library technology (ELT) to a protein-protein interaction target: discovery of a potent class of integrin lymphocyte function-associated antigen 1 (LFA-1) antagonists.

    Science.gov (United States)

    Kollmann, Christopher S; Bai, Xiaopeng; Tsai, Ching-Hsuan; Yang, Hongfang; Lind, Kenneth E; Skinner, Steven R; Zhu, Zhengrong; Israel, David I; Cuozzo, John W; Morgan, Barry A; Yuki, Koichi; Xie, Can; Springer, Timothy A; Shimaoka, Motomu; Evindar, Ghotas

    2014-04-01

    The inhibition of protein-protein interactions remains a challenge for traditional small molecule drug discovery. Here we describe the use of DNA-encoded library technology for the discovery of small molecules that are potent inhibitors of the interaction between lymphocyte function-associated antigen 1 and its ligand intercellular adhesion molecule 1. A DNA-encoded library with a potential complexity of 4.1 billion compounds was exposed to the I-domain of the target protein and the bound ligands were affinity selected, yielding an enriched small-molecule hit family. Compounds representing this family were synthesized without their DNA encoding moiety and found to inhibit the lymphocyte function-associated antigen 1/intercellular adhesion molecule-1 interaction with submicromolar potency in both ELISA and cell adhesion assays. Re-synthesized compounds conjugated to DNA or a fluorophore were demonstrated to bind to cells expressing the target protein. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Integrin α4 Enhances Metastasis and May Be Associated with Poor Prognosis in MYCN-low Neuroblastoma.

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    Shanique A Young

    Full Text Available High-risk neuroblastoma is associated with an overall survival rate of 30-50%. Neuroblastoma-expressed cell adhesion receptors of the integrin family impact cell adhesion, migration, proliferation and survival. Integrin α4 is essential for neural crest cell motility during development, is highly expressed on leukocytes, and is critical for transendothelial migration. Thus, cancer cells that express this receptor may exhibit increased metastatic potential. We show that α4 expression in human and murine neuroblastoma cell lines selectively enhances in vitro interaction with the alternatively spliced connecting segment 1 of fibronectin, as well as vascular cell adhesion molecule-1 and increases migration. Integrin α4 expression enhanced experimental metastasis in a syngeneic tumor model, reconstituting a pattern of organ involvement similar to that seen in patients. Accordingly, antagonism of integrin α4 blocked metastasis, suggesting adhesive function of the integrin is required. However, adhesive function was not sufficient, as mutants of integrin α4 that conserved the matrix-adhesive and promigratory function in vitro were compromised in their metastatic capacity in vivo. Clinically, integrin α4 is more frequently expressed in non-MYNC amplified tumors, and is selectively associated with poor prognosis in this subset of disease. These results reveal an unexpected role for integrin α4 in neuroblastoma dissemination and identify α4 as a potential prognostic indicator and therapeutic target.

  14. Functional consequences of integrin gene mutations in mice

    DEFF Research Database (Denmark)

    Bouvard, D; Brakebusch, C; Gustafsson, E

    2001-01-01

    Integrins are cell-surface receptors responsible for cell attachment to extracellular matrices and to other cells. The application of mouse genetics has significantly increased our understanding of integrin function in vivo. In this review, we summarize the phenotypes of mice carrying mutant inte...

  15. The CD11a partner in Sus scrofa lymphocyte function-associated antigen-1 (LFA-1: mRNA cloning, structure analysis and comparison with mammalian homologues

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    Thomas Anne VT

    2005-10-01

    Full Text Available Abstract Background Lymphocyte function-associated antigen-1 (LFA-1, CD11a/CD18, alphaLbeta2, the most abundant and widely expressed beta2-integrin, is required for many cellular adhesive interactions during the immune response. Many studies have shown that LFA-1 is centrally involved in the pathogenesis of several diseases caused by Repeats-in-toxin (RTX -producing bacteria. Results The porcine-LFA-1 CD11a (alpha subunit coding sequence was cloned, sequenced and compared with the available mammalian homologues in this study. Despite some focal differences, it shares all the main characteristics of these latter. Interestingly, as in sheep and humans, an allelic variant with a triplet insertion resulting in an additional Gln-744 was consistently identified, which suggests an allelic polymorphism that might be biologically relevant. Conclusion Together with the pig CD18-encoding cDNA, which has been available for a long time, the sequence data provided here will allow the successful expression of porcine CD11a, thus giving the first opportunity to express the Sus scrofa beta2-integrin LFA-1 in vitro as a tool to examine the specificities of inflammation in the porcine species.

  16. Blockade of αEβ7 integrin suppresses accumulation of CD8+ and Th9 lymphocytes from patients with IBD in the inflamed gut in vivo.

    Science.gov (United States)

    Zundler, Sebastian; Schillinger, Daniela; Fischer, Anika; Atreya, Raja; López-Posadas, Rocío; Watson, Alastair; Neufert, Clemens; Atreya, Imke; Neurath, Markus F

    2017-11-01

    Therapeutically targeting lymphocyte adhesion is of increasing relevance in IBD. Yet, central aspects of the action of antiadhesion compounds are incompletely understood. We investigated the role of αEβ7 and α4β7 integrins and their blockade by vedolizumab and etrolizumab for trafficking of IBD T lymphocytes in an in vivo model of homing to and retention in the inflamed gut. We explored integrin expression in patients with IBD by flow cytometry and immunohistochemistry, while regulation of integrins was studied in T cell cultures. The functional relevance of integrins was assessed by adhesion assays and a recently established humanised mouse model in dextran sodium sulfate-treated immunodeficient mice. High expression of αEβ7 was noted on CD8 + and CD4 + Th9 cells, while α4β7 was expressed on CD8 + , Th2 and Th17 cells. T cell receptor stimulation and transforming growth factor β were key inducers of αEβ7 on human T cells, while butyric acid suppressed αEβ7. In comparison to α4β7 blockade via vedolizumab, blockade of β7 via etrolizumab surrogate antibody superiorly reduced colonic numbers of CD8 + and Th9 cells in vivo after 3 hours, while no difference was noted after 0.5 hours. AEβ7 expression was higher on CD8 + T cells from patients with IBD under vedolizumab therapy. AEβ7 is of key relevance for gut trafficking of IBD CD8 + T cells and CD4 + Th9 cells in vivo and mainly retention might account for this effect. These findings indicate that blockade of αEβ7 in addition to α4β7 may be particularly effective in intestinal disorders with expansion of CD8 + and Th9 cells such as IBD. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  17. Laminin-binding integrins and their tetraspanin partners as potential antimetastatic targets

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    Stipp, Christopher S.

    2010-01-01

    Within the integrin family of cell adhesion receptors, integrins α3β1, α6β1, α6β4 and α7β1 make up a laminin-binding subfamily. The literature is divided on the role of these laminin-binding integrins in metastasis, with different studies indicating either pro- or antimetastatic functions. The opposing roles of the laminin-binding integrins in different settings might derive in part from their unusually robust associations with tetraspanin proteins. Tetraspanins organise integrins into multiprotein complexes within discrete plasma membrane domains termed tetraspanin-enriched microdomains (TEMs). TEM association is crucial to the strikingly rapid cell migration mediated by some of the laminin-binding integrins. However, emerging data suggest that laminin-binding integrins also promote the stability of E-cadherin-based cell–cell junctions, and that tetraspanins are essential for this function as well. Thus, TEM association endows the laminin-binding integrins with both pro-invasive functions (rapid migration) and anti-invasive functions (stable cell junctions), and the composition of TEMs in different cell types might help determine the balance between these opposing activities. Unravelling the tetraspanin control mechanisms that regulate laminin-binding integrins will help to define the settings where inhibiting the function of these integrins would be helpful rather than harmful, and may create opportunities to modulate integrin activity in more sophisticated ways than simple functional blockade. PMID:20078909

  18. Expression and functional importance of collagen-binding integrins, alpha 1 beta 1 and alpha 2 beta 1, on virus-activated T cells

    DEFF Research Database (Denmark)

    Andreasen, Susanne Ø; Thomsen, Allan R; Koteliansky, Victor E

    2003-01-01

    decreased responses were seen upon transfer of alpha(1)-deficient activated/memory T cells. Thus, expression of alpha(1)beta(1) and alpha(2)beta(1) integrins on activated T cells is directly functionally important for generation of inflammatory responses within tissues. Finally, the inhibitory effect......Adhesive interactions are crucial to cell migration into inflammatory sites. Using murine lymphocytic choriomeningitis virus as an Ag model system, we have investigated expression and function of collagen-binding integrins, alpha(1)beta(1) and alpha(2)beta(1), on activated and memory T cells. Using...... this system and MHC tetramers to define Ag-specific T cells, we demonstrate that contrary to being VLAs, expression of alpha(1)beta(1) and alpha(2)beta(1) can be rapidly induced on acutely activated T cells, that expression of alpha(1)beta(1) remains elevated on memory T cells, and that expression of alpha(1...

  19. Activated integrin VLA-4 localizes to the lamellipodia and mediates T cell migration on VCAM-11

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    Hyun, Young-Min; Chung, Hung-Li; McGrath, James L.; Waugh, Richard E.; Kim, Minsoo

    2009-01-01

    Lymphocyte migration from blood into lymphoid tissues or to sites of inflammation occurs through interactions between cell surface integrins and their ligands expressed on the vascular endothelium and the extracellular matrix. Very Late Antigen-4 (VLA-4, α4β1) is a key integrin in the effective trafficking of lymphocytes. Although it has been well established that integrins undergo functionally significant conformational changes to mediate cell adhesion, there is no mechanistic information that explains how these are dynamically and spatially regulated during lymphocyte polarization and migration. Using dynamic fluorescence resonance energy transfer (FRET) analysis of a novel VLA-4 FRET sensor under total internal reflection fluorescence (TIRF) microscopy, we show that VLA-4 activation localizes to the lamellipodium in living cells. During T cell migration on VCAM-1, VLA-4 activation concurs with spatial redistribution of chemokine receptor and active Rap1 at the leading edge. Selective inhibition of the activated VLA-4 at leading edge with a small molecule inhibitor is sufficient to block T cell migration. These data suggest that a subpopulation of activated VLA-4 is mainly localized to the leading edge of polarized human T cells, and is critical for T cell migration on VCAM-1. PMID:19542447

  20. Cre-loxP–mediated Inactivation of the α6A Integrin Splice Variant In Vivo: Evidence for a Specific Functional Role of α6A in Lymphocyte Migration but Not in Heart Development

    Science.gov (United States)

    Gimond, Clotilde; Baudoin, Christian; van der Neut, Ronald; Kramer, Duco; Calafat, Jero; Sonnenberg, Arnoud

    1998-01-01

    Two splice variants of the α6 integrin subunit, α6A and α6B, with different cytoplasmic domains, have previously been described. While α6B is expressed throughout the development of the mouse, the expression of α6A begins at 8.5 days post coitum and is initially restricted to the myocardium. Later in ontogeny, α6A is found in various epithelia and in certain cells of the immune system. In this study, we have investigated the function of α6A in vivo by generating knockout mice deficient for this splice variant. The Cre- loxP system of the bacteriophage P1 was used to specifically remove the exon encoding the cytoplasmic domain of α6A in embryonic stem cells, and the deletion resulted in the expression of α6B in all tissues that normally express α6A. We show that α6A−/− mice develop normally and are fertile. The substitution of α6A by α6B does not impair the development and function of the heart, hemidesmosome formation in the epidermis, or keratinocyte migration. Furthermore, T cells differentiated normally in α6A−/− mice. However, the substitution of α6A by α6B leads to a decrease in the migration of lymphocytes through laminin-coated Transwell filters and to a reduction of the number of T cells isolated from the peripheral and mesenteric lymph nodes. Lymphocyte homing to the lymph nodes, which involves various types of integrin–ligand interactions, was not affected in the α6A knockout mice, indicating that the reduced number of lymph node cells could not be directly attributed to defects in lymphocyte trafficking. Nevertheless, the expression of α6A might be necessary for optimal lymphocyte migration on laminin in certain pathological conditions. PMID:9763436

  1. Beta1 integrin is not essential for hematopoiesis but is necessary for the T cell-dependent IgM antibody response

    DEFF Research Database (Denmark)

    Brakebusch, Cord; Fillatreau, Simon; Potocnik, Alexandre J

    2002-01-01

    Several experimental evidences suggested that beta1 integrin-mediated adhesion of hematopoietic stem cells (HSC) is important for their function in the bone marrow (BM). Using induced deletion of the beta1 integrin gene restricted to the hematopoietic system, we show that beta1 integrin...... is not essential for HSC retention in the BM, hematopoiesis, and trafficking of lymphocytes. However, immunization with a T cell-dependent antigen resulted in virtually no IgM production and an increased secretion of IgG in mutant mice, while the response to a T cell-independent type 2 antigen showed decreases...

  2. Vesicle-associated membrane protein 2 mediates trafficking of α5β1 integrin to the plasma membrane

    International Nuclear Information System (INIS)

    Hasan, Nazarul; Hu, Chuan

    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 α5β1 integrin. VAMP2 was present on vesicles containing endocytosed β1 integrin. Small interfering RNA (siRNA) silencing of VAMP2 markedly reduced cell surface α5β1 and inhibited cell adhesion and chemotactic migration to fibronectin, the ECM ligand of α5β1, without altering cell surface expression of α2β1 integrin or α3β1 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 α5β1 integrin to the plasma membrane and VAMP2-dependent integrin trafficking is critical in cell adhesion, migration and survival.

  3. The Gain-of-Function Integrin β3 Pro33 Variant Alters the Serotonin System in the Mouse Brain.

    Science.gov (United States)

    Dohn, Michael R; Kooker, Christopher G; Bastarache, Lisa; Jessen, Tammy; Rinaldi, Capria; Varney, Seth; Mazalouskas, Matthew D; Pan, Hope; Oliver, Kendra H; Velez Edwards, Digna R; Sutcliffe, James S; Denny, Joshua C; Carneiro, Ana M D

    2017-11-15

    Engagement of integrins by the extracellular matrix initiates signaling cascades that drive a variety of cellular functions, including neuronal migration and axonal pathfinding in the brain. Multiple lines of evidence link the ITGB3 gene encoding the integrin β3 subunit with the serotonin (5-HT) system, likely via its modulation of the 5-HT transporter (SERT). The ITGB3 coding polymorphism Leu33Pro (rs5918, Pl A2 ) produces hyperactive αvβ3 receptors that influence whole-blood 5-HT levels and may influence the risk for autism spectrum disorder (ASD). Using a phenome-wide scan of psychiatric diagnoses, we found significant, male-specific associations between the Pro33 allele and attention-deficit hyperactivity disorder and ASDs. Here, we used knock-in (KI) mice expressing an Itgb3 variant that phenocopies the human Pro33 variant to elucidate the consequences of constitutively enhanced αvβ3 signaling to the 5-HT system in the brain. KI mice displayed deficits in multiple behaviors, including anxiety, repetitive, and social behaviors. Anatomical studies revealed a significant decrease in 5-HT synapses in the midbrain, accompanied by decreases in SERT activity and reduced localization of SERTs to integrin adhesion complexes in synapses of KI mice. Inhibition of focal adhesion kinase (FAK) rescued SERT function in synapses of KI mice, demonstrating that constitutive active FAK signaling downstream of the Pro32Pro33 integrin αvβ3 suppresses SERT activity. Our studies identify a complex regulation of 5-HT homeostasis and behaviors by integrin αvβ3, revealing an important role for integrins in modulating risk for neuropsychiatric disorders. SIGNIFICANCE STATEMENT The integrin β3 Leu33Pro coding polymorphism has been associated with autism spectrum disorders (ASDs) within a subgroup of patients with elevated blood 5-HT levels, linking integrin β3, 5-HT, and ASD risk. We capitalized on these interactions to demonstrate that the Pro33 coding variation in the murine

  4. A transmembrane polar interaction is involved in the functional regulation of integrin alpha L beta 2.

    Science.gov (United States)

    Vararattanavech, Ardcharaporn; Chng, Choon-Peng; Parthasarathy, Krupakar; Tang, Xiao-Yan; Torres, Jaume; Tan, Suet-Mien

    2010-05-14

    Integrins are heterodimeric transmembrane (TM) receptors formed by noncovalent associations of alpha and beta subunits. Each subunit contains a single alpha-helical TM domain. Inside-out activation of an integrin involves the separation of its cytoplasmic tails, leading to disruption of alphabeta TM packing. The leukocyte integrin alpha L beta 2 is required for leukocyte adhesion, migration, proliferation, cytotoxic function, and antigen presentation. In this study, we show by mutagenesis experiments that the packing of alpha L beta 2 TMs is consistent with that of the integrin alpha IIb beta 3 TMs. However, molecular dynamics simulations of alpha L beta 2 TMs in lipids predicted a polar interaction involving the side chains of alpha L Ser1071 and beta2 Thr686 in the outer-membrane association clasp (OMC). This is supported by carbonyl vibrational shifts observed in isotope-labeled alpha L beta 2 TM peptides that were incorporated into lipid bilayers. Molecular dynamics studies simulating the separation of alpha L beta 2 tails showed the presence of polar interaction during the initial perturbation of the inner-membrane association clasp. When the TMs underwent further separation, the polar interaction was disrupted. OMC polar interaction is important in regulating the functions of beta2 integrins because mutations that disrupt the OMC polar interaction generated constitutively activated alpha L beta 2, alpha M beta 2, and alpha X beta 2 in 293T transfectants. We also show that the expression of mutant beta2 Thr686Gly in beta2-deficient T cells rescued cell adhesion to intercellular adhesion molecule 1, but the cells showed overt elongated morphologies in response to chemokine stromal-cell-derived factor 1 alpha treatment as compared to wild-type beta2-expressing cells. These two TM polar residues are totally conserved in other members of the beta2 integrins in humans and across different species. Our results provide an example of the stabilizing effect of polar

  5. Antagonizing the alpha(4)beta(1) Integrin, but Not alpha(4)beta(7), Inhibits Leukocytic Infiltration of the Central Nervous System in Rhesus Monkey Experimental Autoimmune Encephalomyelitis

    NARCIS (Netherlands)

    Haanstra, Krista G.; Hofman, Sam O.; Estevao, Dave M. Lopes; Blezer, Erwin L. A.; Bauer, Jan; Yang, Li-Li; Wyant, Tim; Csizmadia, Vilmos; 't Hart, Bert A.; Fedyk, Eric R.

    2013-01-01

    The immune system is characterized by the preferential migration of lymphocytes through specific tissues (i.e., tissue tropism). Tissue tropism is mediated, in part, by the alpha(4) integrins expressed by T lymphocytes. The alpha(4)beta(1) integrin mediates migration of memory T lymphocytes into the

  6. 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.

    Science.gov (United States)

    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.

  7. Simulated Microgravity Alters Actin Cytoskeleton and Integrin-Mediated Focal Adhesions of Cultured Human Mesenchymal Stromal Cells

    Science.gov (United States)

    Gershovich, P. M.; Gershovic, J. G.; Buravkova, L. B.

    2008-06-01

    Cytoskeletal alterations occur in several cell types including lymphocytes, glial cells, and osteoblasts, during spaceflight and under simulated microgravity (SMG) (3, 4). One potential mechanism for cytoskeletal gravisensitivity is disruption of extracellular matrix (ECM) and integrin interactions. Focal adhesions are specialized sites of cell-matrix interaction composed of integrins and the diversity of focal adhesion-associated cytoplasmic proteins including vinculin, talin, α-actinin, and actin filaments (4, 5). Integrins produce signals essential for proper cellular function, survival and differentiation. Therefore, we investigated the effects of SMG on F-actin cytoskeleton structure, vinculin focal adhesions, expression of some integrin subtypes and cellular adhesion molecules (CAMs) in mesenchymal stem cells derived from human bone marrow (hMSCs). Simulated microgravity was produced by 3D-clinostat (Dutch Space, Netherlands). Staining of actin fibers with TRITC-phalloidin showed reorganization even after 30 minutes of simulated microgravity. The increasing of cells number with abnormal F-actin was observed after subsequent terms of 3D-clinorotation (6, 24, 48, 120 hours). Randomization of gravity vector altered dimensional structure of stress fibers and resulted in remodeling of actin fibers inside the cells. In addition, we observed vinculin redistribution inside the cells after 6 hours and prolonged terms of clinorotation. Tubulin fibers in a contrast with F-actin and vinculin didn't show any reorganization even after long 3Dclinorotation (120 hours). The expression of integrin α2 increased 1,5-6-fold in clinorotated hMSCs. Also we observed decrease in number of VCAM-1-positive cells and changes in expression of ICAM-1. Taken together, our findings indicate that SMG leads to microfilament and adhesion alterations of hMSCs most probably associated with involvement of some integrin subtypes.

  8. Salt bridge interactions within the β2 integrin α7 helix mediate force-induced binding and shear resistance ability.

    Science.gov (United States)

    Zhang, Xiao; Li, Linda; Li, Ning; Shu, Xinyu; Zhou, Lüwen; Lü, Shouqin; Chen, Shenbao; Mao, Debin; Long, Mian

    2018-01-01

    The functional performance of the αI domain α 7 helix in β 2 integrin activation depends on the allostery of the α 7 helix, which axially slides down; therefore, it is critical to elucidate what factors regulate the allostery. In this study, we determined that there were two conservative salt bridge interaction pairs that constrain both the upper and bottom ends of the α 7 helix. Molecular dynamics (MD) simulations for three β 2 integrin members, lymphocyte function-associated antigen-1 (LFA-1; α L β 2 ), macrophage-1 antigen (Mac-1; α M β 2 ) and α x β 2 , indicated that the magnitude of the salt bridge interaction is related to the stability of the αI domain and the strength of the corresponding force-induced allostery. The disruption of the salt bridge interaction, especially with double mutations in both salt bridges, significantly reduced the force-induced allostery time for all three members. The effects of salt bridge interactions of the αI domain α 7 helix on β 2 integrin conformational stability and allostery were experimentally validated using Mac-1 constructs. The results demonstrated that salt bridge mutations did not alter the conformational state of Mac-1, but they did increase the force-induced ligand binding and shear resistance ability, which was consistent with MD simulations. This study offers new insight into the importance of salt bridge interaction constraints of the αI domain α 7 helix and external force for β 2 integrin function. © 2017 Federation of European Biochemical Societies.

  9. Dual antagonists of integrins.

    Science.gov (United States)

    Nadrah, K; Dolenc, M Sollner

    2005-01-01

    The roles of integrins in pathologies have been studied intensively and only partially explained. This has resulted in the development of several nanomolar antagonists to certain integrins. In most cases, the aim was to produce compounds which are highly selective towards specific integrins. This paradigm has recently shifted a little. Targeting two or more integrins with one compound has become a very attractive concept, especially since it has become clear that several severe disorders, such as pathological angiogenesis, cannot be treated just with highly specific integrin antagonists. This review is aimed to elucidate some aspects regarding the design of drugs with dual activity towards integrins. Integrin structure and tissue distribution will first be described, in order to provide the basis for their functions in various pathologies which will follow. Inhibitors of several pairs of integrins will be described.

  10. Medium-chain, triglyceride-containing lipid emulsions increase human neutrophil beta2 integrin expression, adhesion, and degranulation.

    Science.gov (United States)

    Wanten, G J; Geijtenbeek, T B; Raymakers, R A; van Kooyk, Y; Roos, D; Jansen, J B; Naber, A H

    2000-01-01

    To test the hypothesis that lipid emulsions with different triglyceride structures have distinct immunomodulatory properties, we analyzed human neutrophil adhesion and degranulation after lipid incubation. Neutrophils, isolated from the blood of 10 healthy volunteers, were incubated in medium or physiologic (2.5 mmol/L) emulsions containing long-chain (LCT), medium-chain (MCT), mixed LCT/MCT, or structured (SL) triglycerides. Expression of adhesion molecules and degranulation markers was evaluated by flow cytometry. Also, functional adhesion was investigated by means of a flow cytometric assay using fluorescent beads coated with the integrin ligand intercellular adhesion molecule (ICAM)-1. Although LCT and SL had no effect, LCT/MCT significantly increased expression of the beta2 integrins lymphocyte-function-associated antigen 1 (+18%), macrophage antigen 1 (+387%), p150,95 (+82%), and (alphaDbeta2 (+230%). Degranulation marker expression for azurophilic (CD63, +210%) and specific granules (CD66b, +370%) also significantly increased, whereas L-selectin (CD62L, -70%) decreased. The effects of LCT/MCT were mimicked by the MCT emulsion. ICAM-1 adhesion (% beads bound) was increased by LCT/MCT (34% +/- 4%), whereas LCT (19% +/-3%) and SL (20% +/- 2%) had no effect compared with medium (17% +/- 3%). LCT/MCT and MCT, contrary to LCT and SL emulsions, increased neutrophil beta2 integrin expression, adhesion, and degranulation. Apart from other emulsion constituents, triglyceride chain length might therefore be a key feature in the interaction of lipid emulsions and the phagocyte immune system.

  11. Functions of Tenascin-C and Integrin alpha9beta1 in Mediating Prostate Cancer Bone Metastasis

    Science.gov (United States)

    2017-10-01

    AWARD  NUMBER:          W81XWH-16-1-0523 TITLE:  Functions of Tenascin- C and Integrin alpha9beta1 in Mediating Prostate Cancer Bone Metastasis...Prostat Prostate Cancer  Bone Metastasis   5a.  CONTRACT  NUMBER   Functions of Tenascin- C and Integrin alpha9beta1 in Mediating Prostate Cancer...SUPPLEMENTARY  NOTES 14. ABSTRACT The purpose of this work is to dissect mechanisms responsible for interactions between integrin a9b1 and tenascin- C that are

  12. The newcomer in the integrin family: Integrin α9 in biology and cancer

    DEFF Research Database (Denmark)

    Høye, Anette Melissa; Couchman, John Robert; Wewer, Ulla M.

    2012-01-01

    Integrins are heterodimeric transmembrane receptors regulating cell-cell and cell-extracellular matrix interactions. Of the 24 integrin heterodimers identified in humans, a9ß1 integrin is one of the least studied. a9, together with a4, comprise a more recent evolutionary sub-family of integrins...... of cell types, interacts with many ligands for example fibronectin, tenascin-C and ADAM12, and has been shown to have important functions in processes such as cell adhesion and migration, lung development, lymphatic and venous valve development, and in wound healing. This has sparked an interest...

  13. Glia maturation factor gamma regulates the migration and adherence of human T lymphocytes

    Directory of Open Access Journals (Sweden)

    Lippert Dustin ND

    2012-04-01

    Full Text Available Abstract Background Lymphocyte migration and chemotaxis are essential for effective immune surveillance. A critical aspect of migration is cell polarization and the extension of pseudopodia in the direction of movement. However, our knowledge of the underlying molecular mechanisms responsible for these events is incomplete. Proteomic analysis of the isolated leading edges of CXCL12 stimulated human T cell lines was used to identify glia maturation factor gamma (GMFG as a component of the pseudopodia. This protein is predominantly expressed in hematopoietic cells and it has been shown to regulate cytoskeletal branching. The present studies were undertaken to examine the role of GMFG in lymphocyte migration. Results Microscopic analysis of migrating T-cells demonstrated that GMFG was distributed along the axis of movement with enrichment in the leading edge and behind the nucleus of these cells. Inhibition of GMFG expression in T cell lines and IL-2 dependent human peripheral blood T cells with shRNAmir reduced cellular basal and chemokine induced migration responses. The failure of the cells with reduced GMFG to migrate was associated with an apparent inability to detach from the substrates that they were moving on. It was also noted that these cells had an increased adherence to extracellular matrix proteins such as fibronectin. These changes in adherence were associated with altered patterns of β1 integrin expression and increased levels of activated integrins as detected with the activation specific antibody HUTS4. GMFG loss was also shown to increase the expression of the β2 integrin LFA-1 and to increase the adhesion of these cells to ICAM-1. Conclusions The present studies demonstrate that GMFG is a component of human T cell pseudopodia required for migration. The reduction in migration and increased adherence properties associated with inhibition of GMFG expression suggest that GMFG activity influences the regulation of integrin mediated

  14. Integrins and extracellular matrix in mechanotransduction

    Directory of Open Access Journals (Sweden)

    Ramage L

    2011-12-01

    Full Text Available Lindsay RamageQueen’s Medical Research Institute, University of Edinburgh, Edinburgh, UKAbstract: Integrins are a family of cell surface receptors which mediate cell–matrix and cell–cell adhesions. Among other functions they provide an important mechanical link between the cells external and intracellular environments while the adhesions that they form also have critical roles in cellular signal-transduction. Cell–matrix contacts occur at zones in the cell surface where adhesion receptors cluster and when activated the receptors bind to ligands in the extracellular matrix. The extracellular matrix surrounds the cells of tissues and forms the structural support of tissue which is particularly important in connective tissues. Cells attach to the extracellular matrix through specific cell-surface receptors and molecules including integrins and transmembrane proteoglycans. Integrins work alongside other proteins such as cadherins, immunoglobulin superfamily cell adhesion molecules, selectins, and syndecans to mediate cell–cell and cell–matrix interactions and communication. Activation of adhesion receptors triggers the formation of matrix contacts in which bound matrix components, adhesion receptors, and associated intracellular cytoskeletal and signaling molecules form large functional, localized multiprotein complexes. Cell–matrix contacts are important in a variety of different cell and tissue properties including embryonic development, inflammatory responses, wound healing, and adult tissue homeostasis. This review summarizes the roles and functions of integrins and extracellular matrix proteins in mechanotransduction.Keywords: ligand binding, α subunit, ß subunit, focal adhesion, cell differentiation, mechanical loading, cell–matrix interaction

  15. Separation of integrin-dependent adhesion from morphological changes based on differential PLC specificities.

    Science.gov (United States)

    Wooten, D K; Teague, T K; McIntyre, B W

    1999-01-01

    In normal lymphocytes an inside-out signal up-regulating integrin adhesion is followed by a ligand-mediated outside-in cell spreading signal. Protein kinase C (PKC) inhibition blocks lymphocyte adherence to and spreading on fibronectin. In contrast, putative PLC inhibitors yield distinct differences with respect to adhesion and morphology. The phosphatidylinositol-specific phospholipase C (PLC) inhibitor neomycin blocked spreading of CD3/CD28-activated T cells on fibronectin by disrupting adhesion. Furthermore, when an additional inside-out signal for fibronectin adhesion is unnecessary such as with HPB-ALL T leukemic or phorbol-myristate-acetate-treated normal T cells, neomycin treatment does not alter adhesion or morphology. However, the phosphatidylcholine-specific PLC inhibitor D609 abrogates cell spreading without affecting adhesion to fibronectin in these cells as well as the CD3/CD28-activated T cells. These results strongly suggest that inside-out signaling for the integrin alpha4beta1 in lymphocytes proceeds through phosphatidylinositol-specific PLC and PKC, whereas the outside-in signal utilizes phosphatidylcholine-specific PLC and PKC.

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

    Science.gov (United States)

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

    2002-01-01

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

  17. Leukocyte integrins and their ligand interactions

    Science.gov (United States)

    Hyun, Young-Min; Lefort, Craig T.; Kim, Minsoo

    2010-01-01

    Although critical for cell adhesion and migration during normal immune-mediated reactions, leukocyte integrins are also involved in the pathogenesis of diverse clinical conditions including autoimmune diseases and chronic inflammation. Leukocyte integrins therefore have been targets for anti-adhesive therapies to treat the inflammatory disorders. Recently, the therapeutic potential of integrin antagonists has been demonstrated in psoriasis and multiple sclerosis. However, current therapeutics broadly affect integrin functions and, thus, yield unfavorable side effects. This review discusses the major leukocyte integrins and the anti-adhesion strategies for treating immune diseases. PMID:19184539

  18. Peripheral myelin protein-22 (PMP22 modulates alpha 6 integrin expression in the human endometrium

    Directory of Open Access Journals (Sweden)

    Braun Jonathan

    2011-04-01

    Full Text Available Abstract Background PMP22, a member of the GAS3 family of tetraspan proteins, is associated with a variety of neurological diseases. Previous studies have shown that PMP22 is expressed in proliferative endometrium, but its function within this tissue is poorly understood. In this study, we first characterized the expression of PMP22 in the human menstrual cycle and began to characterize its function in the endometrium. Methods Using a combination of immunohistochemistry and quantitative PCR, we characterized the expression of PMP22 in both proliferative and secretory endometrium. Differences in PMP22 expression between proliferative and secretory endometrium were determined using a Mann-Whitney U test. In order to investigate the influence of PMP22 on α6 integrin expression, cells were created that ectopically overexpressed PMP22 or expressed a siRNA to inhibit its expression. These cells were analyzed for changes in integrins and binding to extracellular matrices. Results In this study, we show that PMP22 expression is higher in proliferative phase than secretory phase. Functionally, we have begun to characterize the functional significance of this expression. Previous studies have suggested a link between PMP22 and α6 integrin, and therefore we asked whether PMP22 could associate or potentially modulate the expression of α6 integrin. Expression of both PMP22 and α6 integrin were detectable in endometrial epithelial and stromal cells, and we show that both proteins can associate and colocalize with each other. To understand if PMP22 directly altered the expression of a6 integrin, we examined cell lines with modulated levels of the protein. Overexpression of PMP22 was sufficient to increase α6 integrin surface expression with a concominant increase in binding to the extracellular matrix laminin, while a reduction in PMP22 suppressed α6 integrin surface expression. Conclusion These findings suggest a physiologic role for PMP22 on the

  19. Peripheral myelin protein-22 (PMP22) modulates alpha 6 integrin expression in the human endometrium.

    Science.gov (United States)

    Rao, Rajiv G; Sudhakar, Deepthi; Hogue, Claire P; Amici, Stephanie; Gordon, Lynn K; Braun, Jonathan; Notterpek, Lucia; Goodglick, Lee; Wadehra, Madhuri

    2011-04-25

    PMP22, a member of the GAS3 family of tetraspan proteins, is associated with a variety of neurological diseases. Previous studies have shown that PMP22 is expressed in proliferative endometrium, but its function within this tissue is poorly understood. In this study, we first characterized the expression of PMP22 in the human menstrual cycle and began to characterize its function in the endometrium. Using a combination of immunohistochemistry and quantitative PCR, we characterized the expression of PMP22 in both proliferative and secretory endometrium. Differences in PMP22 expression between proliferative and secretory endometrium were determined using a Mann-Whitney U test. In order to investigate the influence of PMP22 on α6 integrin expression, cells were created that ectopically overexpressed PMP22 or expressed a siRNA to inhibit its expression. These cells were analyzed for changes in integrins and binding to extracellular matrices. In this study, we show that PMP22 expression is higher in proliferative phase than secretory phase. Functionally, we have begun to characterize the functional significance of this expression. Previous studies have suggested a link between PMP22 and α6 integrin, and therefore we asked whether PMP22 could associate or potentially modulate the expression of α6 integrin. Expression of both PMP22 and α6 integrin were detectable in endometrial epithelial and stromal cells, and we show that both proteins can associate and colocalize with each other. To understand if PMP22 directly altered the expression of a6 integrin, we examined cell lines with modulated levels of the protein. Overexpression of PMP22 was sufficient to increase α6 integrin surface expression with a concominant increase in binding to the extracellular matrix laminin, while a reduction in PMP22 suppressed α6 integrin surface expression. These findings suggest a physiologic role for PMP22 on the expression of α6 integrin. We predict that this may be important for the

  20. Autoimmune hepatitis in association with lymphocytic colitis.

    LENUS (Irish Health Repository)

    Cronin, Edmond M

    2012-02-03

    Autoimmune hepatitis is a rare, chronic inflammatory disorder which has been associated with a number of other auto-immune conditions. However, there are no reports in the medical literature of an association with microscopic (lymphocytic) colitis. We report the case of a 53-year-old woman with several autoimmune conditions, including lymphocytic colitis, who presented with an acute hepatitis. On the basis of the clinical features, serology, and histopathology, we diagnosed autoimmune hepatitis. To our knowledge, this is the first report of autoimmune hepatitis in association with lymphocytic colitis, and lends support to the theory of an autoimmune etiology for lymphocytic colitis.

  1. Endothelial adhesion molecules and leukocyte integrins in preeclamptic patients.

    Science.gov (United States)

    Haller, H; Ziegler, E M; Homuth, V; Drab, M; Eichhorn, J; Nagy, Z; Busjahn, A; Vetter, K; Luft, F C

    1997-01-01

    Endothelial cell activation is important in the pathogenesis of preeclampsia; however, the nature of the activation is unknown. We investigated 22 patients with preeclampsia. 29 normotensive pregnancies, and 18 nonpregnant women to test the hypothesis that serum from preeclamptic patients induces expression of intercellular adhesion molecule-1 (ICAM-1) and vascular adhesion molecule-1 (VCAM-1) and stimulates intracellular free calcium concentrations [Ca2+]i in cultured endothelial cells. We then asked whether the corresponding integrin adhesive counter receptors lymphocyte function-associated antigen-1 (CD11a/CD18), macrophage-1 antigen (CD11b/CD18), p150,95 (CD11c/CD18), and very late activation antigen-4 (CD49/CD29) are increased in patients with preeclampsia. In the pregnant women, the measurements were conducted both before and after delivery. Integrin expression was measured by fluorescent antibody cell sorting analysis using monoclonal antibodies. ICAM-1 and VCAM-1 were analyzed on endothelial cells by enzyme-linked immunosorbent assay. [Ca2+]i was measured with fura 2. Serum from preeclamptic patients increased endothelial cell ICAM-1 expression but not VCAM-1 expression. Preeclamptic patients' serum also increased [Ca2+]i in endothelial cells compared with serum from normal nonpregnant or normal pregnant women. Endothelial cell [Ca2+]i concentrations were correlated with the ICAM-1 expression in preeclamptic patients (r = .80, P preclampsia and normal pregnancy compared with the nonpregnant state. The expression decreased significantly after delivery in both groups. Our results demonstrate that serum from preeclamptic women induces increased ICAM-1 surface expression on endothelial cells, while the expression of the integrin counterreceptors was not different. The effect on endothelial cells may be related to an increase in [Ca2+]i. The effect on cultured endothelial cells and the rapid decrease after delivery suggests the presence of a circulating serum

  2. Beyond the Matrix: The Many Non-ECM Ligands for Integrins

    Directory of Open Access Journals (Sweden)

    Bryce LaFoya

    2018-02-01

    Full Text Available The traditional view of integrins portrays these highly conserved cell surface receptors as mediators of cellular attachment to the extracellular matrix (ECM, and to a lesser degree, as coordinators of leukocyte adhesion to the endothelium. These canonical activities are indispensable; however, there is also a wide variety of integrin functions mediated by non-ECM ligands that transcend the traditional roles of integrins. Some of these unorthodox roles involve cell-cell interactions and are engaged to support immune functions such as leukocyte transmigration, recognition of opsonization factors, and stimulation of neutrophil extracellular traps. Other cell-cell interactions mediated by integrins include hematopoietic stem cell and tumor cell homing to target tissues. Integrins also serve as cell-surface receptors for various growth factors, hormones, and small molecules. Interestingly, integrins have also been exploited by a wide variety of organisms including viruses and bacteria to support infectious activities such as cellular adhesion and/or cellular internalization. Additionally, the disruption of integrin function through the use of soluble integrin ligands is a common strategy adopted by several parasites in order to inhibit blood clotting during hematophagy, or by venomous snakes to kill prey. In this review, we strive to go beyond the matrix and summarize non-ECM ligands that interact with integrins in order to highlight these non-traditional functions of integrins.

  3. Interaction with glycosaminoglycans is required for cyclophilin B to trigger integrin-mediated adhesion of peripheral blood T lymphocytes to extracellular matrix.

    Science.gov (United States)

    Allain, Fabrice; Vanpouille, Christophe; Carpentier, Mathieu; Slomianny, Marie-Christine; Durieux, Sandrine; Spik, Geneviève

    2002-03-05

    Cyclophilins A and B (CyPA and CyPB) are cyclosporin A-binding proteins that are involved in inflammatory events. We have reported that CyPB interacts with two types of cell-surface-binding sites. The first site corresponds to a functional receptor and requires interaction with the central core of CyPB. This region is highly conserved in cyclophilins, suggesting that CyPA and CyPB might share biological activities mediated by interaction with this receptor. The second site is identified with glycosaminoglycans (GAGs), the binding region located in the N terminus of CyPB. The difference in the N-terminal extensions of CyPA and CyPB suggests that a unique interaction with GAGs might account for selective activity of CyPB. To explore this hypothesis, we analyzed the lymphocyte responses triggered by CyPA, CyPB, and CyPB(KKK-), a mutant unable to interact with GAGs. The three ligands seemed capable enough to elicit calcium signal and chemotaxis by binding to the same signaling receptor. In contrast, only CyPB enhanced firm adhesion of T cells to the extracellular matrix. This activity depended on the interactions with GAGs and signaling receptor. CyPB-mediated adhesion required CD147 presumably because it was a costimulatory molecule and was related to an activation of alpha4beta1 and alpha4beta7 integrins. Finally, we showed that CyPB was capable mainly to enhance T cell adhesion of the CD4+CD45RO+ subset. The present data indicate that CyPB rather than CyPA is a proinflammatory factor for T lymphocytes and highlight the crucial role of CyPB-GAG interaction in the chemokine-like activity of this protein.

  4. [Occurrence of associated tumours in chronic lymphocytic leukemia].

    Science.gov (United States)

    Szerafin, László; Jakó, János; Varju, Lóránt

    2016-10-01

    Chronic lymphocytic leukemia is one of the most common hematologic malignancy. The aim of the authors was to investigate the characteristics of malignancies associated with chronic lymphocytic leukemia in patients diagnozed between 2000 and 2015. Data of patients with chronic lymphocytic leukemia who had other associated tumours were analysed using the Leukemia/Lymphoma Registry of the Szabolcs-Szatmár-Bereg County, Hungary and patient records. Between January 1, 2000 and December 31, 2015, 526 patients with chronic lymphocytic leukemia were diagnosed. 95 patients of the 526 patients (18.06%) were diagnosed as having associated other tumours. In 48/95 patients (50.5%) the first diagnosed tumour was chronic lymphocytic leukemia, in 23/95 patients (24.2%) the first recognized malignancy was the associated tumour, whereas in 24/95 patients (25.3%) synchron tumours were diagnosed. The number of patients with more than one associated tumour was 10/95 (10.5%). The total number of tumours was 107. The incidence of chronic lymphoid leukemia increased in the period between 2000 and 2015 as compared to the period between 1983 and 1999 (3.19 vs 5.65/100 000 person/year). The occurrence of associated malignancies increased as well (8.06% vs 18.06%). In addition to the most common tumours (colorectal, breast, lung, prostate), skin squamous cell carcinoma (17/95 patients; 17.9%) and melanoma (6/95 patients; 6.3%) also frequently occurred. The second malignancies were most frequently discovered after the diagnosis of chronic lymphocytic leukemia and synchron tumours accounting for 78.5% (84/107) of all associated tumours. The incidence of second malignancies decreased 10 years after the diagnosis of chronic lymphocytic leukemia. The possible reasons for the high frequency of other tumours associated with chronic lymphocytic leukemia are elderly age of patients, immunsuppressed state and, presumably, chemotherapy of patients with chronic lymphocytic leukemia. During the follow up

  5. Direct Thy-1/alphaVbeta3 integrin interaction mediates neuron to astrocyte communication.

    Science.gov (United States)

    Hermosilla, Tamara; Muñoz, Daniel; Herrera-Molina, Rodrigo; Valdivia, Alejandra; Muñoz, Nicolás; Nham, Sang-Uk; Schneider, Pascal; Burridge, Keith; Quest, Andrew F G; Leyton, Lisette

    2008-06-01

    Thy-1 is an abundant neuronal glycoprotein of poorly defined function. We recently provided evidence indicating that Thy-1 clusters a beta3-containing integrin in astrocytes to induce tyrosine phosphorylation, RhoA activation and the formation of focal adhesions and stress fibers. To date, the alpha subunit partner of beta3 integrin in DI TNC1 astrocytes is unknown. Similarly, the ability of neuronal, membrane-bound Thy-1 to trigger astrocyte signaling via integrin engagement remains speculation. Here, evidence that alphav forms an alphavbeta3 heterodimer in DI TNC1 astrocytes was obtained. In neuron-astrocyte association assays, the presence of either anti-alphav or anti-beta3 integrin antibodies reduced cell-cell interaction demonstrating the requirement of both integrin subunits for this association. Moreover, anti-Thy-1 antibodies blocked stimulation of astrocytes by neurons but not the binding of these two cell types. Thus, neuron-astrocyte association involved binding between molecular components in addition to the Thy-1-integrin; however, the signaling events leading to focal adhesion formation in astrocytes depended exclusively on the latter interaction. Additionally, wild-type (RLD) but not mutated (RLE) Thy-1 was shown to directly interact with alphavbeta3 integrin by Surface Plasmon Resonance analysis. This interaction was promoted by divalent cations and was species-independent. Together, these results demonstrate that the alphavbeta3 integrin heterodimer interacts directly with Thy-1 present on neuronal cells to stimulate astrocytes.

  6. Tensin stabilizes integrin adhesive contacts in Drosophila.

    Science.gov (United States)

    Torgler, Catherine N; Narasimha, Maithreyi; Knox, Andrea L; Zervas, Christos G; Vernon, Matthew C; Brown, Nicholas H

    2004-03-01

    We report the functional characterization of the Drosophila ortholog of tensin, a protein implicated in linking integrins to the cytoskeleton and signaling pathways. A tensin null was generated and is viable with wing blisters, a phenotype characteristic of loss of integrin adhesion. In tensin mutants, mechanical abrasion is required during wing expansion to cause wing blisters, suggesting that tensin strengthens integrin adhesion. The localization of tensin requires integrins, talin, and integrin-linked kinase. The N-terminal domain and C-terminal PTB domain of tensin provide essential recruitment signals. The intervening SH2 domain is not localized on its own. We suggest a model where tensin is recruited to sites of integrin adhesion via its PTB and N-terminal domains, localizing the SH2 domain so that it can interact with phosphotyrosine-containing proteins, which stabilize the integrin link to the cytoskeleton.

  7. Integrin-directed modulation of macrophage responses to biomaterials.

    Science.gov (United States)

    Zaveri, Toral D; Lewis, Jamal S; Dolgova, Natalia V; Clare-Salzler, Michael J; Keselowsky, Benjamin G

    2014-04-01

    Macrophages are the primary mediator of chronic inflammatory responses to implanted biomaterials, in cases when the material is either in particulate or bulk form. Chronic inflammation limits the performance and functional life of numerous implanted medical devices, and modulating macrophage interactions with biomaterials to mitigate this response would be beneficial. The integrin family of cell surface receptors mediates cell adhesion through binding to adhesive proteins nonspecifically adsorbed onto biomaterial surfaces. In this work, the roles of integrin Mac-1 (αMβ2) and RGD-binding integrins were investigated using model systems for both particulate and bulk biomaterials. Specifically, the macrophage functions of phagocytosis and inflammatory cytokine secretion in response to a model particulate material, polystyrene microparticles were investigated. Opsonizing proteins modulated microparticle uptake, and integrin Mac-1 and RGD-binding integrins were found to control microparticle uptake in an opsonin-dependent manner. The presence of adsorbed endotoxin did not affect microparticle uptake levels, but was required for the production of inflammatory cytokines in response to microparticles. Furthermore, it was demonstrated that integrin Mac-1 and RGD-binding integrins influence the in vivo foreign body response to a bulk biomaterial, subcutaneously implanted polyethylene terephthalate. A thinner foreign body capsule was formed when integrin Mac-1 was absent (~30% thinner) or when RGD-binding integrins were blocked by controlled release of a blocking peptide (~45% thinner). These findings indicate integrin Mac-1 and RGD-binding integrins are involved and may serve as therapeutic targets to mitigate macrophage inflammatory responses to both particulate and bulk biomaterials. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Diacylglycerol kinase zeta negatively regulates CXCR4-stimulated T lymphocyte firm arrest to ICAM-1 under shear flow.

    Science.gov (United States)

    Lee, Dooyoung; Kim, Jiyeon; Beste, Michael T; Koretzky, Gary A; Hammer, Daniel A

    2012-06-01

    T lymphocyte arrest within microvasculature is an essential process in immune surveillance and the adaptive immune response. Integrins and chemokines coordinately regulate when and where T cells stop under flow via chemokine-triggered inside-out activation of integrins. Diacylglycerol kinases (DGKs) regulate the levels of diacylglycerol (DAG) which in turn determine the activation of guanine nucleotide exchange factors (GEFs) and Ras proximity 1 (Rap1) molecules crucial to the activation of integrin lymphocyte function-associated antigen 1 (LFA-1). However, how the level of DGK regulates chemokine-stimulated LFA-1-mediated T cell arrest under flow is unknown. Using a combination of experiment and computational modeling, we demonstrate that DGKζ is a crucial regulator of CXCL12-triggered T cell arrest on surfaces presenting inter-cellular adhesion molecule 1 (ICAM-1). Using flow chamber assays, we found that the deficiency of DGKζ in T cells significantly increased firm arrest to ICAM-1-coated substrates and shortened the time to stop without altering the rolling velocity. These results suggest that DGKζ levels affect LFA-1-mediated T cell firm arrest, but not P-selectin-mediated rolling during CXCL12 stimulation. We accurately simulated the role of DGKζ in firm arrest of T cells computationally using an Integrated-Signaling Adhesive Dynamics (ISAD). In the absence of DGK catalytic reaction, the model cells rolled for a significantly shorter time before arrest, compared to when DGK molecules were present. Predictions of our model for T cell arrest quantitatively match experimental results. Overall these results demonstrate that DGKζ is a negative regulator of CXCL12-triggered inside-out activation of LFA-1 and firm adhesion of T cells under shear flow.

  9. Epitopes in α8β1 and other RGD-binding integrins delineate classes of integrin-blocking antibodies and major binding loops in α subunits

    OpenAIRE

    Norihisa Nishimichi; Nagako Kawashima; Yasuyuki Yokosaki

    2015-01-01

    Identification of epitopes for integrin-blocking monoclonal antibodies (mAbs) has aided our understanding of structure-function relationship of integrins. We mapped epitopes of chicken anti-integrin-α8-subunit-blocking mAbs by mutational analyses, examining regions that harboured all mapped epitopes recognized by mAbs against other α-subunits in the RGD-binding-integrin subfamily. Six mAbs exhibited blocking function, and these mAbs recognized residues on the same W2:41-loop on the top-face o...

  10. Professional memory CD4+ T lymphocytes preferentially reside and rest in the bone marrow.

    Science.gov (United States)

    Tokoyoda, Koji; Zehentmeier, Sandra; Hegazy, Ahmed N; Albrecht, Inka; Grün, Joachim R; Löhning, Max; Radbruch, Andreas

    2009-05-01

    CD4(+) T lymphocytes are key to immunological memory. Here we show that in the memory phase of specific immune responses, most of the memory CD4(+) T lymphocytes had relocated into the bone marrow (BM) within 3-8 weeks after their generation-a process involving integrin alpha2. Antigen-specific memory CD4(+) T lymphocytes highly expressed Ly-6C, unlike most splenic CD44(hi)CD62L(-) CD4(+) T lymphocytes. In adult mice, more than 80% of Ly-6C(hi)CD44(hi)CD62L(-) memory CD4(+) T lymphocytes were in the BM. In the BM, they associated to IL-7-expressing VCAM-1(+) stroma cells. Gene expression and proliferation were downregulated, indicating a resting state. Upon challenge with antigen, they rapidly expressed cytokines and CD154 and efficiently induced the production of high-affinity antibodies by B lymphocytes. Thus, in the memory phase of immunity, memory helper T cells are maintained in BM as resting but highly reactive cells in survival niches defined by IL-7-expressing stroma cells.

  11. Variation in one residue associated with the metal ion-dependent adhesion site regulates αIIbβ3 integrin ligand binding affinity.

    Directory of Open Access Journals (Sweden)

    Joel Raborn

    Full Text Available The Asp of the RGD motif of the ligand coordinates with the β I domain metal ion dependent adhesion site (MIDAS divalent cation, emphasizing the importance of the MIDAS in ligand binding. There appears to be two distinct groups of integrins that differ in their ligand binding affinity and adhesion ability. These differences may be due to a specific residue associated with the MIDAS, particularly the β3 residue Ala(252 and corresponding Ala in the β1 integrin compared to the analogous Asp residue in the β2 and β7 integrins. Interestingly, mutations in the adjacent to MIDAS (ADMIDAS of integrins α4β7 and αLβ2 increased the binding and adhesion abilities compared to the wild-type, while the same mutations in the α2β1, α5β1, αVβ3, and αIIbβ3 integrins demonstrated decreased ligand binding and adhesion. We introduced a mutation in the αIIbβ3 to convert this MIDAS associated Ala(252 to Asp. By combination of this mutant with mutations of one or two ADMIDAS residues, we studied the effects of this residue on ligand binding and adhesion. Then, we performed molecular dynamics simulations on the wild-type and mutant αIIbβ3 integrin β I domains, and investigated the dynamics of metal ion binding sites in different integrin-RGD complexes. We found that the tendency of calculated binding free energies was in excellent agreement with the experimental results, suggesting that the variation in this MIDAS associated residue accounts for the differences in ligand binding and adhesion among different integrins, and it accounts for the conflicting results of ADMIDAS mutations within different integrins. This study sheds more light on the role of the MIDAS associated residue pertaining to ligand binding and adhesion and suggests that this residue may play a pivotal role in integrin-mediated cell rolling and firm adhesion.

  12. Functional single-walled carbon nanotubes based on an integrin αvβ3 monoclonal antibody for highly efficient cancer cell targeting

    International Nuclear Information System (INIS)

    Ou Zhongmin; Wu Baoyan; Xing Da; Zhou Feifan; Wang Huiying; Tang Yonghong

    2009-01-01

    The application of single-walled carbon nanotubes (SWNTs) in the field of biomedicine is becoming an entirely new and exciting topic. In this study, a novel functional SWNT based on an integrin α v β 3 monoclonal antibody was developed and was used for cancer cell targeting in vitro. SWNTs were first modified by phospholipid-bearing polyethylene glycol (PL-PEG). The PL-PEG functionalized SWNTs were then conjugated with protein A. A SWNT-integrin α v β 3 monoclonal antibody system (SWNT-PEG-mAb) was thus constructed by conjugating protein A with the fluorescein labeled integrin α v β 3 monoclonal antibody. In vitro study revealed that SWNT-PEG-mAb presented a high targeting efficiency on integrin α v β 3 -positive U87MG cells with low cellular toxicity, while for integrin α v β 3 -negative MCF-7 cells, the system had a low targeting efficiency, indicating that the high targeting to U87MG cells was due to the specific integrin targeting of the monoclonal antibody. In conclusion, SWNT-PEG-mAb developed in this research is a potential candidate for cancer imaging and drug delivery in cancer targeting therapy.

  13. Molecular dynamics and docking simulation of a natural variant of Activated Protein C with impaired protease activity: implications for integrin-mediated antiseptic function.

    Science.gov (United States)

    D'Ursi, Pasqualina; Orro, Alessandro; Morra, Giulia; Moscatelli, Marco; Trombetti, Gabriele; Milanesi, Luciano; Rovida, Ermanna

    2015-01-01

    Activated Protein C (APC) is a multifunctional serine protease, primarily known for its anticoagulant function in the coagulation system. Several studies have already elucidated its role in counteracting apoptosis and inflammation in cells, while significant effort is still ongoing for defining its involvement in sepsis. Earlier literature has shown that the antiseptic function of APC is mediated by its binding to leukocyte integrins, which is due to the presence of the integrin binding motif Arg-Gly-Asp at the N-terminus of the APC catalytic chain. Many natural mutants have been identified in patients with Protein C deficiency diagnosis including a variant of specificity pocket (Gly216Asp). In this work, we present a molecular model of the complex of APC with αVβ3 integrin obtained by protein-protein docking approach. A computational analysis of this variant is hereby presented, based on molecular dynamics and docking simulations, aiming at investigating the effects of the Gly216Asp mutation on the protein conformation and inferring its functional implications. Our study shows that such mutation is likely to impair the protease activity while preserving the overall protein fold. Moreover, superposition of the integrin binding motifs in wild-type and mutant forms suggests that the interaction with integrin can still occur and thus the mutant is likely to retain its antiseptic function related to the neutrophyl integrin binding. Therapeutic applications could result in this APC mutant which retains antiseptic function without anticoagulant side effects.

  14. Tumour exosome integrins determine organotropic metastasis.

    Science.gov (United States)

    Hoshino, Ayuko; Costa-Silva, Bruno; Shen, Tang-Long; Rodrigues, Goncalo; Hashimoto, Ayako; Tesic Mark, Milica; Molina, Henrik; Kohsaka, Shinji; Di Giannatale, Angela; Ceder, Sophia; Singh, Swarnima; Williams, Caitlin; Soplop, Nadine; Uryu, Kunihiro; Pharmer, Lindsay; King, Tari; Bojmar, Linda; Davies, Alexander E; Ararso, Yonathan; Zhang, Tuo; Zhang, Haiying; Hernandez, Jonathan; Weiss, Joshua M; Dumont-Cole, Vanessa D; Kramer, Kimberly; Wexler, Leonard H; Narendran, Aru; Schwartz, Gary K; Healey, John H; Sandstrom, Per; Labori, Knut Jørgen; Kure, Elin H; Grandgenett, Paul M; Hollingsworth, Michael A; de Sousa, Maria; Kaur, Sukhwinder; Jain, Maneesh; Mallya, Kavita; Batra, Surinder K; Jarnagin, William R; Brady, Mary S; Fodstad, Oystein; Muller, Volkmar; Pantel, Klaus; Minn, Andy J; Bissell, Mina J; Garcia, Benjamin A; Kang, Yibin; Rajasekhar, Vinagolu K; Ghajar, Cyrus M; Matei, Irina; Peinado, Hector; Bromberg, Jacqueline; Lyden, David

    2015-11-19

    Ever since Stephen Paget's 1889 hypothesis, metastatic organotropism has remained one of cancer's greatest mysteries. Here we demonstrate that exosomes from mouse and human lung-, liver- and brain-tropic tumour cells fuse preferentially with resident cells at their predicted destination, namely lung fibroblasts and epithelial cells, liver Kupffer cells and brain endothelial cells. We show that tumour-derived exosomes uptaken by organ-specific cells prepare the pre-metastatic niche. Treatment with exosomes from lung-tropic models redirected the metastasis of bone-tropic tumour cells. Exosome proteomics revealed distinct integrin expression patterns, in which the exosomal integrins α6β4 and α6β1 were associated with lung metastasis, while exosomal integrin αvβ5 was linked to liver metastasis. Targeting the integrins α6β4 and αvβ5 decreased exosome uptake, as well as lung and liver metastasis, respectively. We demonstrate that exosome integrin uptake by resident cells activates Src phosphorylation and pro-inflammatory S100 gene expression. Finally, our clinical data indicate that exosomal integrins could be used to predict organ-specific metastasis.

  15. Integrin cytoplasmic domain-associated protein-1 (ICAP-1) interacts with the ROCK-I kinase at the plasma membrane

    NARCIS (Netherlands)

    Stroeken, Peter J. M.; Alvarez, Belén; van Rheenen, Jacco; Wijnands, Yvonne M.; Geerts, Dirk; Jalink, Kees; Roos, Ed

    2006-01-01

    The integrin cytoplasmic domain-associated protein-1 (ICAP-1) binds via its C-terminal PTB (phosphotyrosine-binding) domain to the cytoplasmic tails of beta1 but not other integrins. Using the yeast two-hybrid assay, we found that ICAP-1 binds the ROCK-I kinase, an effector of the RhoA GTPase. By

  16. Tumor suppressor KAI1 affects integrin αvβ3-mediated ovarian cancer cell adhesion, motility, and proliferation

    International Nuclear Information System (INIS)

    Ruseva, Zlatna; Geiger, Pamina Xenia Charlotte; Hutzler, Peter; Kotzsch, Matthias; Luber, Birgit; Schmitt, Manfred; Gross, Eva; Reuning, Ute

    2009-01-01

    The tetraspanin KAI1 had been described as a metastasis suppressor in many different cancer types, a function for which associations of KAI1 with adhesion and signaling receptors of the integrin superfamily likely play a role. In ovarian cancer, integrin αvβ3 correlates with tumor progression and its elevation in vitro provoked enhanced cell adhesion accompanied by significant increases in cell motility and proliferation in the presence of its major ligand vitronectin. In the present study, we characterized integrin αvβ3-mediated tumor biological effects as a function of cellular KAI1 restoration and proved for the first time that KAI1, besides its already known physical crosstalk with β1-integrins, also colocalizes with integrin αvβ3. Functionally, elevated KAI1 levels drastically increased integrin αvβ3/vitronectin-dependent ovarian cancer cell adhesion. Since an intermediate level of cell adhesive strength is required for optimal cell migration, we next studied ovarian cancer cell motility as a function of KAI1 restoration. By time lapse video microscopy, we found impaired integrin αvβ3/vitronectin-mediated cell migration most probably due to strongly enhanced cellular immobilization onto the adhesion-supporting matrix. Moreover, KAI1 reexpression significantly diminished cell proliferation. These data strongly indicate that KAI1 may suppress ovarian cancer progression by inhibiting integrin αvβ3/vitronectin-provoked tumor cell motility and proliferation as important hallmarks of the oncogenic process.

  17. Expression of FLNa in human melanoma cells regulates the function of integrin α1β1 and phosphorylation and localisation of PKB/AKT/ERK1/2 kinases.

    Science.gov (United States)

    Krebs, Kristi; Ruusmann, Anu; Simonlatser, Grethel; Velling, Teet

    2015-12-01

    FLNa is a ubiquitous cytoskeletal protein that links transmembrane receptors, including integrins, to F-actin and functions as a signalling intermediate. We investigated FLNa's role in the function of integrin-type collagen receptors, EGF-EGFR signalling and regulation of PKB/Akt and ERK1/2. Using FLNa-deficient M2 human melanoma cells, and same cells expressing EGFP-FLNa (M2F) or its Ig-like repeats 1-8+24, 8-15+24 and 16-24, we found that in M2F and M2 8-15+24 cells, EGF induced the increased phosphorylation of PKB/Akt and ERK1/2. In M2F cells EGF induced the localisation of these kinases to cell nucleus and lamellipodia, respectively, and the ERK1/2 phosphorylation-dependent co-immunoprecipitation of FLNa with ERK1/2. Only M2F and M2 8-15+24 cells adhered to and spread on type I collagen whereas on fibronectin all cells behaved similarly. α1β1 and α2β1 were the integrin-type collagen receptors expressed on these cells with primarily α1β1 localising to focal contacts and affecting cell adhesion and migration in a manner dependent on FLNa or its Ig-like repeats 8-15. Our results suggest a role for FLNa repeats 8-15 in the α1-subunit-dependent regulation of integrin α1β1 function, EGF-EGFR signalling to PKB/Akt and ERK1/2, identify ERK1/2 in EGF-induced FLNa-associated protein complexes, and show that the function of different integrins is subjected to differential regulation by FLNa. Copyright © 2015. Published by Elsevier GmbH.

  18. A region in urokinase plasminogen receptor domain III controlling a functional association with alpha5beta1 integrin and tumor growth

    DEFF Research Database (Denmark)

    Chaurasia, Pratima; Aguirre-Ghiso, Julio; Liang, Olin D

    2006-01-01

    PAR(wt) or the uPAR(S245A) mutant. Transfecting uPAR(wt) into cells with low endogenous levels of uPAR, inactive integrin, low ERK activity, and a dormant phenotype in vivo restores these functions and reinstates growth in vivo. In contrast, transfection of the same cells with uPAR(S245A) elicits only very small...... and tumor growth implicates it as a possible specific target for cancer therapy....

  19. Conservation of the human integrin-type beta-propeller domain in bacteria.

    Directory of Open Access Journals (Sweden)

    Bhanupratap Chouhan

    Full Text Available Integrins are heterodimeric cell-surface receptors with key functions in cell-cell and cell-matrix adhesion. Integrin α and β subunits are present throughout the metazoans, but it is unclear whether the subunits predate the origin of multicellular organisms. Several component domains have been detected in bacteria, one of which, a specific 7-bladed β-propeller domain, is a unique feature of the integrin α subunits. Here, we describe a structure-derived motif, which incorporates key features of each blade from the X-ray structures of human αIIbβ3 and αVβ3, includes elements of the FG-GAP/Cage and Ca(2+-binding motifs, and is specific only for the metazoan integrin domains. Separately, we searched for the metazoan integrin type β-propeller domains among all available sequences from bacteria and unicellular eukaryotic organisms, which must incorporate seven repeats, corresponding to the seven blades of the β-propeller domain, and so that the newly found structure-derived motif would exist in every repeat. As the result, among 47 available genomes of unicellular eukaryotes we could not find a single instance of seven repeats with the motif. Several sequences contained three repeats, a predicted transmembrane segment, and a short cytoplasmic motif associated with some integrins, but otherwise differ from the metazoan integrin α subunits. Among the available bacterial sequences, we found five examples containing seven sequential metazoan integrin-specific motifs within the seven repeats. The motifs differ in having one Ca(2+-binding site per repeat, whereas metazoan integrins have three or four sites. The bacterial sequences are more conserved in terms of motif conservation and loop length, suggesting that the structure is more regular and compact than those example structures from human integrins. Although the bacterial examples are not full-length integrins, the full-length metazoan-type 7-bladed β-propeller domains are present, and

  20. Use of integrin-linked kinase to extend function of encapsulated pancreatic tissue

    International Nuclear Information System (INIS)

    Blanchette, James O; Langer, Steven J; Leinwand, Leslie L; Sahai, Suchit; Topiwala, Pritesh S; Anseth, Kristi S

    2010-01-01

    We have studied the impact of overexpression of an intracellular signaling protein, integrin-linked kinase (ILK), on the survival and function of encapsulated islet tissue used for the treatment of type 1 diabetes. The dimensions of the encapsulated tissue can impact the stresses placed on the tissue and ILK overexpression shows the ability to extend function of dissociated cells as well as intact islets. These results suggest that lost cell-extracellular matrix interactions in cell encapsulation systems can lead to decreased insulin secretion and ILK signaling is a target to overcome this phenomenon. (communication)

  1. Use of integrin-linked kinase to extend function of encapsulated pancreatic tissue

    Energy Technology Data Exchange (ETDEWEB)

    Blanchette, James O [Department of Chemical Engineering, University of South Carolina, Columbia, SC (United States); Langer, Steven J; Leinwand, Leslie L [Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, CO (United States); Sahai, Suchit; Topiwala, Pritesh S [Biomedical Engineering Program, University of South Carolina, Columbia, SC (United States); Anseth, Kristi S, E-mail: blanchej@cec.sc.ed [Howard Hughes Medical Institute, Boulder, CO (United States)

    2010-12-15

    We have studied the impact of overexpression of an intracellular signaling protein, integrin-linked kinase (ILK), on the survival and function of encapsulated islet tissue used for the treatment of type 1 diabetes. The dimensions of the encapsulated tissue can impact the stresses placed on the tissue and ILK overexpression shows the ability to extend function of dissociated cells as well as intact islets. These results suggest that lost cell-extracellular matrix interactions in cell encapsulation systems can lead to decreased insulin secretion and ILK signaling is a target to overcome this phenomenon. (communication)

  2. Psoriasiform skin disease in transgenic pigs with high-copy ectopic expression of human integrins α2 and β1

    Science.gov (United States)

    Staunstrup, Nicklas Heine; Stenderup, Karin; Mortensen, Sidsel; Primo, Maria Nascimento; Steiniche, Torben; Liu, Ying; Li, Rong; Schmidt, Mette; Purup, Stig; Dagnæs-Hansen, Frederik; Schrøder, Lisbeth Dahl; Svensson, Lars; Petersen, Thomas Kongstad; Callesen, Henrik; Bolund, Lars

    2017-01-01

    ABSTRACT Psoriasis is a complex human-specific disease characterized by perturbed keratinocyte proliferation and a pro-inflammatory environment in the skin. Porcine skin architecture and immunity are very similar to that in humans, rendering the pig a suitable animal model for studying the biology and treatment of psoriasis. Expression of integrins, which is normally confined to the basal layer of the epidermis, is maintained in suprabasal keratinocytes in psoriatic skin, modulating proliferation and differentiation as well as leukocyte infiltration. Here, we generated minipigs co-expressing integrins α2 and β1 in suprabasal epidermal layers. Integrin-transgenic minipigs born into the project displayed skin phenotypes that correlated with the number of inserted transgenes. Molecular analyses were in good concordance with histological observations of psoriatic hallmarks, including hypogranulosis and T-lymphocyte infiltration. These findings mark the first creation of minipigs with a psoriasiform phenotype resembling human psoriasis and demonstrate that integrin signaling plays a key role in psoriasis pathology. PMID:28679670

  3. Exosomes derived from human macrophages suppress endothelial cell migration by controlling integrin trafficking.

    Science.gov (United States)

    Lee, Hee Doo; Kim, Yeon Hyang; Kim, Doo-Sik

    2014-04-01

    Integrin trafficking, including internalization, recycling, and lysosomal degradation, is crucial for the regulation of cellular functions. Exosomes, nano-sized extracellular vesicles, are believed to play important roles in intercellular communications. This study demonstrates that exosomes released from human macrophages negatively regulate endothelial cell migration through control of integrin trafficking. Macrophage-derived exosomes promote internalization of integrin β1 in primary HUVECs. The internalized integrin β1 persistently accumulates in the perinuclear region and is not recycled back to the plasma membrane. Experimental results indicate that macrophage-derived exosomes stimulate trafficking of internalized integrin β1 to lysosomal compartments with a corresponding decrease in the integrin destined for recycling endosomes, resulting in proteolytic degradation of the integrin. Moreover, ubiquitination of HUVEC integrin β1 is enhanced by the exosomes, and exosome-mediated integrin degradation is blocked by bafilomycin A, a lysosomal degradation inhibitor. Macrophage-derived exosomes were also shown to effectively suppress collagen-induced activation of the mitogen-activated protein kinase/extracellular signal-regulated kinase signaling pathway and HUVEC migration, which are both dependent on integrin β1. These observations provide new insight into the functional significance of exosomes in the regulation of integrin trafficking. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Diverse roles of integrin receptors in articular cartilage.

    Science.gov (United States)

    Shakibaei, M; Csaki, C; Mobasheri, A

    2008-01-01

    Integrins are heterodimeric integral membrane proteins made up of alpha and beta subunits. At least eighteen alpha and eight beta subunit genes have been described in mammals. Integrin family members are plasma membrane receptors involved in cell adhesion and active as intra- and extracellular signalling molecules in a variety of processes including embryogenesis, hemostasis, tissue repair, immune response and metastatic spread of tumour cells. Integrin beta 1 (beta1-integrin), the protein encoded by the ITGB1 gene (also known as CD29 and VLAB), is a multi-functional protein involved in cell-matrix adhesion, cell signalling, cellular defense, cell adhesion, protein binding, protein heterodimerisation and receptor-mediated activity. It is highly expressed in the human body (17.4 times higher than the average gene in the last updated revision of the human genome). The extracellular matrix (ECM) of articular cartilage is a unique environment. Interactions between chondrocytes and the ECM regulate many biological processes important to homeostasis and repair of articular cartilage, including cell attachment, growth, differentiation and survival. The beta1-integrin family of cell surface receptors appears to play a major role in mediating cell-matrix interactions that are important in regulating these fundamental processes. Chondrocyte mechanoreceptors have been proposed to incorporate beta1-integrins and mechanosensitive ion channels which link with key ECM, cytoskeletal and signalling proteins to maintain the chondrocyte phenotype, prevent chondrocyte apoptosis and regulate chondrocyte-specific gene expression. This review focuses on the expression and function of beta1-integrins in articular chondrocytes, its role in the unique biology of these cells and its distribution in cartilage.

  5. Differential gene expression by integrin β7+ and β7- memory T helper cells

    Directory of Open Access Journals (Sweden)

    Yang Yee

    2004-07-01

    Full Text Available Abstract Background The cell adhesion molecule integrin α4β7 helps direct the migration of blood lymphocytes to the intestine and associated lymphoid tissues. We hypothesized that β7+ and β7- blood memory T helper cells differ in their expression of genes that play a role in the adhesion or migration of T cells. Results RNA was prepared from β7+ and β7- CD4+ CD45RA- blood T cells from nine normal human subjects and analyzed using oligonucleotide microarrays. Of 21357 genes represented on the arrays, 16 were more highly expressed in β7+ cells and 18 were more highly expressed in β7- cells (≥1.5 fold difference and adjusted P + memory/effector T cells than on β7- cells. Conclusions Memory/effector T cells that express integrin β7 have a distinct pattern of expression of a set of gene transcripts. Several of these molecules can affect cell adhesion or chemotaxis and are therefore likely to modulate the complex multistep process that regulates trafficking of CD4+ memory T cell subsets with different homing behaviors.

  6. Spleen lymphocyte function modulated by a cocoa-enriched diet.

    Science.gov (United States)

    Ramiro-Puig, E; Pérez-Cano, F J; Ramírez-Santana, C; Castellote, C; Izquierdo-Pulido, M; Permanyer, J; Franch, A; Castell, M

    2007-09-01

    Previous studies have shown the down-regulating in vitro effect of cocoa flavonoids on lymphocyte and macrophage activation. In the present paper, we report the capacity of a long-term rich cocoa diet to modulate macrophage cytokine secretion and lymphocyte function in young rats. Weaned rats received natural cocoa (4% or 10% food intake), containing 32 mg flavonoids/g, for 3 weeks. Spleen immune function was then evaluated through the analysis of lymphocyte composition, their proliferative response and their ability to secrete cytokines and Ig. In addition, the status of activated peritoneal macrophages was established through tumour necrosis factor (TNF)-alpha secretion. The richest cocoa diet (10%) caused a reduction of TNF-alpha secretion by peritoneal macrophages showing anti-inflammatory activity. Similarly, although a 10% cocoa diet increased lymphocyte proliferation rate, it down-regulated T helper 2 (Th2)-related cytokines and decreased Ig secretion. These changes were accompanied by an increase in spleen B cell proportion and a decrease in Th cell percentage. In summary, these results demonstrate the functional activity of a cocoa-high dosage in down-regulating the immune response that might be beneficial in hypersensitivity and autoimmunity.

  7. Integrin β1, osmosensing, and chemoresistance in mouse ehrlich carcinoma cells

    DEFF Research Database (Denmark)

    Sørensen, Belinda Halling; Rasmussen, Line Jee Hartmann; Broberg, Bjørn Sindballe

    2015-01-01

    BACKGROUND/AIMS: Altered expression of the integrin family of cell adhesion receptors has been associated with initiation, progression, and metastasis of solid tumors as well as in the development of chemoresistance. Here, we investigated the role of integrins, in particular integrin β1, in cell ...

  8. Characterization of Laminin Binding Integrin Internalization in Prostate Cancer Cells†

    Science.gov (United States)

    Das, Lipsa; Anderson, Todd A.; Gard, Jaime M.C.; Sroka, Isis C.; Strautman, Stephanie R.; Nagle, Raymond B.; Morrissey, Colm; Knudsen, Beatrice S.; Cress, Anne E.

    2017-01-01

    Laminin binding integrins α6 (CD49f) and α3 (CD49c) are persistently but differentially expressed in prostate cancer (PCa). Integrin internalization is an important determinant of their cell surface expression and function. Using flow cytometry, and first order kinetic modelling, we quantitated the intrinsic internalization rates of integrin subunits in a single cycle of internalization. In PCa cell line DU145, α6 integrin internalized with a rate constant (kactual) of 3.25min−1, 3-fold faster than α3 integrin (1.0 min−1), 1.5-fold faster than the vitronectin binding αv integrin (CD51) (2.2 min−1), and significantly slower than the unrelated transferrin receptor (CD71) (15 min−1). Silencing of α3 integrin protein expression in DU145, PC3 and PC3B1 cells resulted in up to a 1.71-fold increase in kactual for α6 integrin. The internalized α6 integrin was targeted to early endosomes but not to lamp1 vesicles. Depletion of α3 integrin expression resulted in redistribution of α6β4 integrin to an observed cell-cell staining pattern that is consistent with a suprabasal distribution observed in epidermis and early PIN lesions in PCa. Depletion of α3 integrin increased cell migration by 1.8 fold, which was dependent on α6β1 integrin. Silencing of α6 integrin expression however, had no significant effect on the kactual of α3 integrin or its distribution in early endosomes. These results indicate that α3 and α6 integrins have significantly different internalization kinetics and that coordination exists between them for internalization. This article is protected by copyright. All rights reserved PMID:27509031

  9. Characterization of Laminin Binding Integrin Internalization in Prostate Cancer Cells.

    Science.gov (United States)

    Das, Lipsa; Anderson, Todd A; Gard, Jaime M C; Sroka, Isis C; Strautman, Stephanie R; Nagle, Raymond B; Morrissey, Colm; Knudsen, Beatrice S; Cress, Anne E

    2017-05-01

    Laminin binding integrins α6 (CD49f) and α3 (CD49c) are persistently but differentially expressed in prostate cancer (PCa). Integrin internalization is an important determinant of their cell surface expression and function. Using flow cytometry, and first order kinetic modeling, we quantitated the intrinsic internalization rates of integrin subunits in a single cycle of internalization. In PCa cell line DU145, α6 integrin internalized with a rate constant (k actual ) of 3.25 min -1 , threefold faster than α3 integrin (1.0 min -1 ), 1.5-fold faster than the vitronectin binding αv integrin (CD51) (2.2 min -1 ), and significantly slower than the unrelated transferrin receptor (CD71) (15 min -1 ). Silencing of α3 integrin protein expression in DU145, PC3, and PC3B1 cells resulted in up to a 1.71-fold increase in k actual for α6 integrin. The internalized α6 integrin was targeted to early endosomes but not to lamp1 vesicles. Depletion of α3 integrin expression resulted in redistribution of α6β4 integrin to an observed cell-cell staining pattern that is consistent with a suprabasal distribution observed in epidermis and early PIN lesions in PCa. Depletion of α3 integrin increased cell migration by 1.8-fold, which was dependent on α6β1 integrin. Silencing of α6 integrin expression however, had no significant effect on the k actual of α3 integrin or its distribution in early endosomes. These results indicate that α3 and α6 integrins have significantly different internalization kinetics and that coordination exists between them for internalization. J. Cell. Biochem. 118: 1038-1049, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  10. Oscillatory fluid flow elicits changes in morphology, cytoskeleton and integrin-associated molecules in MLO-Y4 cells, but not in MC3T3-E1 cells

    Directory of Open Access Journals (Sweden)

    Huiyun Xu

    2012-01-01

    Full Text Available Interstitial fluid flow stress is one of the most important mechanical stimulations of bone cells under physiological conditions. Osteocytes and osteoblasts act as primary mechanosensors within bones, and in vitro are able to respond to fluid shear stress, both morphologically and functionally. However, there is little information about the response of integrin-associated molecules using both osteoblasts and osteocytes. In this study, we investigated the changes in response to 2 hours of oscillatory fluid flow stress in the MLO-Y4 osteocyte-like cell line and the MC3T3-E1 osteoblast-like cell line. MLO-Y4 cells exhibited a significant increase in the expression of integrin-associated molecules, including OPN, CD44, vinculin and integrin avp3. However, there was no or limited increase observed in MC3T3-E1 osteoblast-like cells. Cell area and fiber stress formation were also markedly promoted by fluid flow only in MLO-Y4 cells. But the numbers of processes per cell remain unaffected in both cell lines.

  11. Age-specific function of α5β1 integrin in microglial migration during early colonization of the developing mouse cortex.

    Science.gov (United States)

    Smolders, Sophie Marie-Thérèse; Swinnen, Nina; Kessels, Sofie; Arnauts, Kaline; Smolders, Silke; Le Bras, Barbara; Rigo, Jean-Michel; Legendre, Pascal; Brône, Bert

    2017-07-01

    Microglia, the immune cells of the central nervous system, take part in brain development and homeostasis. They derive from primitive myeloid progenitors that originate in the yolk sac and colonize the brain mainly through intensive migration. During development, microglial migration speed declines which suggests that their interaction with the microenvironment changes. However, the matrix-cell interactions allowing dispersion within the parenchyma are unknown. Therefore, we aimed to better characterize the migration behavior and to assess the role of matrix-integrin interactions during microglial migration in the embryonic brain ex vivo. We focused on microglia-fibronectin interactions mediated through the fibronectin receptor α5β1 integrin because in vitro work indirectly suggested a role for this ligand-receptor pair. Using 2-photon time-lapse microscopy on acute ex vivo embryonic brain slices, we found that migration occurs in a saltatory pattern and is developmentally regulated. Most importantly, there is an age-specific function of the α5β1 integrin during microglial cortex colonization. At embryonic day (E) 13.5, α5β1 facilitates migration while from E15.5, it inhibits migration. These results indicate a developmentally regulated function of α5β1 integrin in microglial migration during colonization of the embryonic brain. © 2017 Wiley Periodicals, Inc.

  12. AID protein expression in chronic lymphocytic leukemia/small lymphocytic lymphoma is associated with poor prognosis and complex genetic alterations.

    Science.gov (United States)

    Leuenberger, Mona; Frigerio, Simona; Wild, Peter J; Noetzli, Franziska; Korol, Dimitri; Zimmermann, Dieter R; Gengler, Carole; Probst-Hensch, Nicole M; Moch, Holger; Tinguely, Marianne

    2010-02-01

    The biological behavior of chronic lymphocytic leukemia and small lymphocytic lymphoma is unpredictable. Nonetheless, non-mutated IgV(H) gene rearrangement, ATM (11q22-23) and p53 (17p13) deletion are recognized as unfavorable prognosticators in chronic lymphocytic leukemia. The mRNA expression of activation-induced cytidine deaminase (AID), an enzyme indispensable for somatic hypermutation processes, was claimed to be predictive of non-mutated chronic lymphocytic leukemia cells in blood. Here, we evaluated AID protein expression compared with known molecular and immunohistochemical prognostic indicators in 71 chronic lymphocytic leukemia/small lymphocytic lymphoma patients using a tissue microarray approach. We found AID heterogeneously expressed in tumor cells as shown by colocalization analysis for CD5 and CD23. Ki-67 positive paraimmunoblasts of the proliferation centers displayed the highest expression. This observation is reflected by a significant association of AID positivity with a high proliferation rate (P=0.012). ATM deletion was detected in 10% (6/63) of patients and p53 deletion in 19% (13/67) of patients. Moreover, both ATM (P=0.002) and p53 deletion (P=0.004) were significantly associated with AID. IgV(H) gene mutation was seen in 45% (27/60) of patients. Twenty-five percent (17/69) of patients with AID-positive chronic lymphocytic leukemia/small lymphocytic lymphoma displayed a shorter survival than AID-negative chronic lymphocytic leukemia/small lymphocytic lymphoma patients (61 vs 130 months, P=0.001). Although there was a trend, we could not show an association with the IgV(H) gene mutation status. Taken together, our study shows that AID expression is an indicator of an unfavorable prognosis in chronic lymphocytic leukemia/small lymphocytic lymphoma patients, although it is not a surrogate marker for the IgV(H) status. Furthermore, the microenvironment of proliferation centers seems to influence AID regulation and might be an initiating factor

  13. Cardiac integrins the ties that bind.

    Science.gov (United States)

    Simpson, D G; Reaves, T A; Shih, D T; Burgess, W; Borg, T K; Terracio, L

    1998-01-01

    An elaborate series of morphogenetic events must be precisely coordinated during development to promote the formation of the elaborate three-dimensional structure of the normal heart. In this study we focus on discussing how interconnections between the cardiac myocyte and its surrounding environment regulate cardiac form and function. In vitro experiments from our laboratories provide direct evidence that cardiac cell shape is regulated by a dynamic interaction between constituents of the extracellular matrix (ECM) and by specific members of the integrin family of matrix receptors. Our data indicates that phenotypic information is stored in the tertiary structure and chemical identity of the ECM. This information appears to be actively communicated and transduced by the α1β1 integrin molecule into an intracellular signal that regulates cardiac cell shape and myofibrillar organization. In this study we have assessed the phenotypic consequences of suppressing the expression and accumulation of the α1 integrin molecule in aligned cultures of cardiac myocytes. In related experiments we have examined how the overexpression of α2 and α5 integrin, integrins normally not present or present at very low copy number on the cell surface of neonatal cardiac myocytes, affect cardiac protein metabolism. We also consider how biochemical signals and the mechanical signals mediated by the integrins may converge on common intracellular signaling pathways in the heart. Experiments with the whole embryo culture system indicate that angiotensin II, a peptide that carries information concerning cardiac load, plays a role in controling cardiac looping and the proliferation of myofibrils during development.

  14. Effects of atomic bomb radiation on differentiation of B lymphocytes and on the function of concanavalin A-induced suppressor T lymphocytes

    International Nuclear Information System (INIS)

    Yamada, Y.; Neriishi, S.; Ishimaru, T.; Shimba, N.; Hamilton, H.B.; Ohgushi, Y.; Koyanagi, M.; Ichimaru, M.

    1985-01-01

    The differentiation of peripheral blood B lymphocytes into immunoglobulin-producing cells (Ig-PC) by pokeweed mitogen (PWM) and the function of concanavalin A (Con A)-induced suppressor T lymphocytes were examined to elucidate the late effects of atomic bomb radiation. A total of 140 individuals, 70 with an exposure dose of 100 rad or more and an equal number with an exposure dose of 0 rad matched by sex and age, were selected from the Nagasaki Adult Health Study (AHS) sample. Both the differentiation of peripheral blood B lymphocytes into Ig-PC by PWM and the function of Con A-induced suppressor T lymphocytes tended to be more depressed in the exposed group than in the control group, but a statistically significant difference could not be observed between the two groups. The function of Con A-induced suppressor T lymphocytes tended to decrease with age, but a statistical significance was detected only for percentage suppression against IgM-PC

  15. Epitopes in α8β1 and other RGD-binding integrins delineate classes of integrin-blocking antibodies and major binding loops in α subunits.

    Science.gov (United States)

    Nishimichi, Norihisa; Kawashima, Nagako; Yokosaki, Yasuyuki

    2015-09-09

    Identification of epitopes for integrin-blocking monoclonal antibodies (mAbs) has aided our understanding of structure-function relationship of integrins. We mapped epitopes of chicken anti-integrin-α8-subunit-blocking mAbs by mutational analyses, examining regions that harboured all mapped epitopes recognized by mAbs against other α-subunits in the RGD-binding-integrin subfamily. Six mAbs exhibited blocking function, and these mAbs recognized residues on the same W2:41-loop on the top-face of the β-propeller. Loop-tips sufficiently close to W2:41 (face was identified as an additional component of the epitope of one antibody, clone YZ5. Binding sequences on the two loops were conserved in virtually all mammals, and that on W3:34 was also conserved in chickens. These indicate 1) YZ5 binds both top and bottom loops, and the binding to W3:34 is by interactions to conserved residues between immunogen and host species, 2) five other blocking mAbs solely bind to W2:41 and 3) the α8 mAbs would cross-react with most mammals. Comparing with the mAbs against the other α-subunits of RGD-integrins, two classes were delineated; those binding to "W3:34 and an top-loop", and "solely W2:41", accounting for 82% of published RGD-integrin-mAbs.

  16. ADAM2 interactions with mouse eggs and cell lines expressing α4/α9 (ITGA4/ITGA9 integrins: implications for integrin-based adhesion and fertilization.

    Directory of Open Access Journals (Sweden)

    Ulyana V Desiderio

    2010-10-01

    Full Text Available Integrins are heterodimeric cell adhesion molecules, with 18 α (ITGA and eight β (ITGB subunits forming 24 heterodimers classified into five families. Certain integrins, especially the α(4/α(9 (ITGA4/ITGA9 family, interact with members of the ADAM (a disintegrin and metalloprotease family. ADAM2 is among the better characterized and also of interest because of its role in sperm function. Having shown that ITGA9 on mouse eggs participates in mouse sperm-egg interactions, we sought to characterize ITGA4/ITGA9-ADAM2 interactions.An anti-β(1/ITGB1 function-blocking antibody that reduces sperm-egg binding significantly inhibited ADAM2 binding to mouse eggs. Analysis of integrin subunit expression indicates that mouse eggs could express at least ten different integrins, five in the RGD-binding family, two in the laminin-binding family, two in the collagen-binding family, and ITGA9-ITGB1. Adhesion assays to characterize ADAM2 interactions with ITGA4/ITGA9 family members produced the surprising result that RPMI 8866 cell adhesion to ADAM2 was inhibited by an anti-ITGA9 antibody, noteworthy because ITGA9 has only been reported to dimerize with ITGB1, and RPMI 8866 cells lack detectable ITGB1. Antibody and siRNA studies demonstrate that ITGB7 is the β subunit contributing to RPMI 8866 adhesion to ADAM2.These data indicate that a novel integrin α-β combination, ITGA9-ITGB7 (α(9β(7, in RPMI 8866 cells functions as a binding partner for ADAM2. ITGA9 had previously only been reported to dimerize with ITGB1. Although ITGA9-ITGB7 is unlikely to be a widely expressed integrin and appears to be the result of "compensatory dimerization" occurring in the context of little/no ITGB1 expression, the data indicate that ITGA9-ITGB7 functions as an ADAM binding partner in certain cellular contexts, with implications for mammalian fertilization and integrin function.

  17. Cross-talk between integrins α1β1 and α2β1 in renal epithelial cells

    International Nuclear Information System (INIS)

    Abair, Tristin D.; Sundaramoorthy, Munirathinam; Chen, Dong; Heino, Jyrki; Ivaska, Johanna; Hudson, Billy G.; Sanders, Charles R.; Pozzi, Ambra; Zent, Roy

    2008-01-01

    The collagen-binding integrins α1β1 and α2β1 have profoundly different functions, yet they are often co-expressed in epithelial cells. When both integrins are expressed in the same cell, it has been suggested that α1β1 negatively regulates integrin α2β1-dependent functions. In this study we utilized murine ureteric bud (UB) epithelial cells, which express no functionally detectable levels of endogenous integrins α1β1 and α2β1, to determine the mechanism whereby this regulation occurs. We demonstrate that UB cells expressing integrin α2β1, but not α1β1 adhere, migrate and proliferate on collagen I as well as form cellular cords in 3D collagen I gels. Substitution of the transmembrane domain of the integrin α2 subunit with that of α1 results in decreased cell adhesion, migration and cord formation. In contrast, substitution of the integrin α2 cytoplasmic tail with that of α1, decreases cell migration and cord formation, but increases proliferation. When integrin α1 and α2 subunits are co-expressed in UB cells, the α1 subunit negatively regulates integrin α2β1-dependent cord formation, adhesion and migration and this inhibition requires expression of both α1 and α2 tails. Thus, we provide evidence that the transmembrane and cytoplasmic domains of the α2 integrin subunit, as well as the α1 integrin subunit, regulate integrin α2β1 cell function

  18. Higher plasma CD4 lymphocyte count correlates with better cognitive function in human immunodeficiency virus-acquired immunodeficiency syndrome (HIV-AIDS) patients

    Science.gov (United States)

    Fitri, F. I.; Rambe, A. S.; Fitri, A.

    2018-03-01

    Neurocognitive disorders in HIV-AIDS are still prevalent despite the use of antiretroviral therapy and seem to be under-recognized. Plasma lymphocyte CD4 count is a marker for general immunology status, but its association with cognitive function remains unclear. The aim of this study was to determine the correlation between plasma CD4 lymphocyte and cognitive function in HIV-AIDS patients.This was a cross-sectional study involving 48 HIV-AIDS patients. All subjects underwent physical, neurologic examination and Montreal Cognitive Assessment-Indonesian Version (MoCA-INA) to assess cognitive function and measurement of lymphocyte CD4 counts.This study included 48 subjects consisted of 29 males (60.4%) and 19 females (39.6%). The mean age was 39.17±11.21 years old. There was a significant correlation between CD4 lymphocyte counts and MoCA-INA score (r=0.347, p=0.016).Higher plasma CD4 lymphocyte count is correlated with better cognitive function in HIV-AIDS patients.

  19. Integrin specificity and enhanced cellular activities associated with surfaces presenting a recombinant fibronectin fragment compared to RGD supports.

    Science.gov (United States)

    Petrie, Timothy A; Capadona, Jeffrey R; Reyes, Catherine D; García, Andrés J

    2006-11-01

    Biomimetic strategies focusing on presenting short bioadhesive oligopeptides, including the arginine-glycine-aspartic acid (RGD) motif present in numerous adhesive proteins, on a non-fouling support have emerged as promising approaches to improve cellular activities and healing responses. Nevertheless, these bio-inspired strategies are limited by low activity of the oligopeptides compared to the native ligand due to the absence of complementary or modulatory domains. In the present analysis, we generated well-defined biointerfaces presenting RGD-based ligands of increasing complexity to directly compare their biological activities in terms of cell adhesion strength, integrin binding and signaling. Mixed self-assembled monolayers of alkanethiols on gold were optimized to engineer robust supports that present anchoring groups for ligand tethering within a non-fouling, protein adsorption-resistant background. Controlled bioadhesive interfaces were generated by tethering adhesive ligands via standard peptide chemistry. On a molar basis, biointerfaces functionalized with the FNIII7-10 recombinant fragment presenting the RGD and PHSRN adhesive motifs in the correct structural context exhibited significantly higher adhesion strength, FAK activation, and cell proliferation rate than supports presenting RGD ligand or RGD-PHSRN, an oligopeptide presenting these two sites separated by a polyglycine linker. Moreover, FNIII7-10-functionalized surfaces displayed specificity for alpha5beta1 integrin, while cell adhesion to supports presenting RGD or RGD-PHSRN was primarily mediated by alphavbeta3 integrin. These results are significant to the rational engineering of bioactive materials that convey integrin binding specificity for directed cellular and tissue responses in biomedical and biotechnological applications.

  20. Genetic analysis of beta1 integrin "activation motifs" in mice

    DEFF Research Database (Denmark)

    Czuchra, Aleksandra; Meyer, Hannelore; Legate, Kyle R

    2006-01-01

    -null phenotype in vivo. Surprisingly, neither the substitution of the tyrosines with phenylalanine nor the aspartic acid with alanine resulted in an obvious defect. These data suggest that the NPXY motifs of the beta1 integrin tail are essential for beta1 integrin function, whereas tyrosine phosphorylation...

  1. Migratory and adhesive cues controlling innate-like lymphocyte surveillance of the pathogen-exposed surface of the lymph node.

    Science.gov (United States)

    Zhang, Yang; Roth, Theodore L; Gray, Elizabeth E; Chen, Hsin; Rodda, Lauren B; Liang, Yin; Ventura, Patrick; Villeda, Saul; Crocker, Paul R; Cyster, Jason G

    2016-08-03

    Lymph nodes (LNs) contain innate-like lymphocytes that survey the subcapsular sinus (SCS) and associated macrophages for pathogen entry. The factors promoting this surveillance behavior have not been defined. Here, we report that IL7R(hi)Ccr6(+) lymphocytes in mouse LNs rapidly produce IL17 upon bacterial and fungal challenge. We show that these innate-like lymphocytes are mostly LN resident. Ccr6 is required for their accumulation near the SCS and for efficient IL17 induction. Migration into the SCS intrinsically requires S1pr1, whereas movement from the sinus into the parenchyma involves the integrin LFA1 and its ligand ICAM1. CD169, a sialic acid-binding lectin, helps retain the cells within the sinus, preventing their loss in lymph flow. These findings establish a role for Ccr6 in augmenting innate-like lymphocyte responses to lymph-borne pathogens, and they define requirements for cell movement between parenchyma and SCS in what we speculate is a program of immune surveillance that helps achieve LN barrier immunity.

  2. Functional and clinical relevance of VLA-4 (CD49d/CD29) in ibrutinib-treated chronic lymphocytic leukemia

    Science.gov (United States)

    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

  3. Elucidating the role of select cytoplasmic proteins in altering diffusion of integrin receptors.

    Science.gov (United States)

    Sander, Suzanne; Arora, Neha; Smith, Emily A

    2012-06-01

    Cytoplasmic proteins that affect integrin diffusion in the cell membrane are identified using a combination of fluorescence recovery after photobleaching (FRAP) and RNA interference. Integrin receptors are essential for many cellular events, and alterations in lateral diffusion are one mechanism for modulating their function. In cells expressing native cytoplasmic protein concentrations and spread on a slide containing integrin extracellular ligand, 45 ± 2% of the integrin is mobile with a time-dependent 5.2 ± 0.9 × 10(-9) cm(2)/s diffusion coefficient at 1 s. The time exponent is 0.90 ± 0.07, indicating integrin diffusion moderately slows at longer times. The role of a specific cytoplasmic protein in altering integrin diffusion is revealed through changes in the FRAP curve after reducing the cytoplasmic protein's expression. Decreased expression of cytoplasmic proteins rhea, focal adhesion kinase (FAK), or steamer duck decreases the integrin mobile fraction. For rhea and FAK, there is a concomitant shift to Brownian (i.e., time-independent) diffusion at reduced concentrations of these proteins. In contrast, when the expression of actin 42A, dreadlocks, paxillin, integrin-linked kinase (ILK), or vinculin is reduced, integrin diffusion generally becomes more constrained with an increase in the integrin mobile fraction. This same change in integrin diffusion is measured in the absence of integrin extracellular ligand. The results indicate breaking the extracellular ligand-integrin-cytoskeletal linkage alters integrin diffusion properties, and, in most cases, there is no correlation between integrin and lipid diffusion properties.

  4. Expression of alpha V integrin is modulated by Epstein-Barr virus nuclear antigen 3C and the metastasis suppressor Nm23-H1 through interaction with the GATA-1 and Sp1 transcription factors

    International Nuclear Information System (INIS)

    Choudhuri, Tathagata; Verma, Subhash C.; Lan, Ke; Robertson, Erle S.

    2006-01-01

    Epstein-Barr virus (EBV) is a lymphotrophic herpesvirus infecting most of the world's population. It is associated with a number of human lymphoid and epithelial tumors and lymphoproliferative diseases in immunocompromised patients. A subset of latent EBV antigens is required for immortalization of primary B-lymphocytes. The metastatic suppressor Nm23-H1 which is downregulated in human invasive breast carcinoma reduces the migration and metastatic activity of breast carcinoma cells when expressed from a heterologous promoter. Interestingly, the EBV nuclear antigen 3C (EBNA3C) reverses these activities of Nm23-H1. The alpha V integrins recognize a variety of ligands for signaling and are involved in cell migration and proliferation and also serve as major receptors for extracellular-matrix-mediated cell adhesion and migration. The goal of this study was to determine if Nm23-H1 and EBNA3C can modulate alpha V integrin expression and downstream activities. The results of our studies indicate that Nm23-H1 downregulates alpha V intregrin expression in a dose responsive manner. In contrast, EBNA3C can upregulate alpha V integrin expression. Furthermore, the study showed that the association of the Sp1 and GATA transcription factors with Nm23-H1 is required for modulation of the alpha V integrin activity. Thus, these results suggest a direct correlation between the alpha V integrin expression and the interaction of Nm23-H1 with EBNA3C

  5. High αv Integrin Level of Cancer Cells Is Associated with Development of Brain Metastasis in Athymic Rats.

    Science.gov (United States)

    Wu, Yingjen Jeffrey; Pagel, Michael A; Muldoon, Leslie L; Fu, Rongwei; Neuwelt, Edward A

    2017-08-01

    Brain metastases commonly occur in patients with malignant skin, lung and breast cancers resulting in high morbidity and poor prognosis. Integrins containing an αv subunit are cell adhesion proteins that contribute to cancer cell migration and cancer progression. We hypothesized that high expression of αv integrin cell adhesion protein promoted metastatic phenotypes in cancer cells. Cancer cells from different origins were used and studied regarding their metastatic ability and intetumumab, anti-αv integrin mAb, sensitivity using in vitro cell migration assay and in vivo brain metastases animal models. The number of brain metastases and the rate of occurrence were positively correlated with cancer cell αv integrin levels. High αv integrin-expressing cancer cells showed significantly faster cell migration rate in vitro than low αv integrin-expressing cells. Intetumumab significantly inhibited cancer cell migration in vitro regardless of αv integrin expression level. Overexpression of αv integrin in cancer cells with low αv integrin level accelerated cell migration in vitro and increased the occurrence of brain metastases in vivo. αv integrin promotes brain metastases in cancer cells and may mediate early steps in the metastatic cascade, such as adhesion to brain vasculature. Targeting αv integrin with intetumumab could provide clinical benefit in treating cancer patients who develop metastases. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  6. Gfi1b controls integrin signaling-dependent cytoskeleton dynamics and organization in megakaryocytes.

    Science.gov (United States)

    Beauchemin, Hugues; Shooshtarizadeh, Peiman; Vadnais, Charles; Vassen, Lothar; Pastore, Yves D; Möröy, Tarik

    2017-03-01

    Mutations in GFI1B are associated with inherited bleeding disorders called GFI1B -related thrombocytopenias. We show here that mice with a megakaryocyte-specific Gfi1b deletion exhibit a macrothrombocytopenic phenotype along a megakaryocytic dysplasia reminiscent of GFI1B -related thrombocytopenia. GFI1B deficiency increases megakaryocyte proliferation and affects their ploidy, but also abrogates their responsiveness towards integrin signaling and their ability to spread and reorganize their cytoskeleton. Gfi1b -null megakaryocytes are also unable to form proplatelets, a process independent of integrin signaling. GFI1B-deficient megakaryocytes exhibit aberrant expression of several components of both the actin and microtubule cytoskeleton, with a dramatic reduction of α-tubulin. Inhibition of FAK or ROCK, both important for actin cytoskeleton organization and integrin signaling, only partially restored their response to integrin ligands, but the inhibition of PAK, a regulator of the actin cytoskeleton, completely rescued the responsiveness of Gfi1b -null megakaryocytes to ligands, but not their ability to form proplatelets. We conclude that Gfi1b controls major functions of megakaryocytes such as integrin-dependent cytoskeleton organization, spreading and migration through the regulation of PAK activity whereas the proplatelet formation defect in GFI1B-deficient megakaryocytes is due, at least partially, to an insufficient α-tubulin content. Copyright© Ferrata Storti Foundation.

  7. Role of β1-Integrin in Colorectal Cancer: Case-Control Study

    Science.gov (United States)

    Oh, Bo-Young; Kim, Kwang Ho; Chung, Soon Sup; Hong, Kyoung Sook

    2014-01-01

    Purpose In the metastatic process, interactions between circulating tumor cells (CTCs) and the extracellular matrix or surrounding cells are required. β1-Integrin may mediate these interactions. The aim of this study was to investigate whether β1-integrin is associated with the detection of CTCs in colorectal cancer. Methods We enrolled 30 patients with colorectal cancer (experimental group) and 30 patients with benign diseases (control group). Blood samples were obtained from each group, carcinoembryonic antigen (CEA) mRNA for CTCs marker and β1-integrin mRNA levels were estimated by using reverse transcription-polymerase chain reaction, and the results were compared between the two groups. In the experimental group, preoperative results were compared with postoperative results for each marker. In addition, we analyzed the correlation between the expressions of β1-integrin and CEA. Results CEA mRNA was detected more frequently in colorectal cancer patients than in control patients (P = 0.008). CEA mRNA was significantly reduced after surgery in the colorectal cancer patients (P = 0.032). β1-Integrin mRNA was detected more in colorectal cancer patients than in the patients with benign diseases (P < 0.001). In colorectal cancer patients, expression of β1-integrin mRNA was detected more for advanced-stage cancer than for early-stage cancer (P = 0.033) and was significantly decreased after surgery (P < 0.001). In addition, expression of β1-integrin mRNA was significantly associated with that of CEA mRNA in colorectal cancer patients (P = 0.001). Conclusion In conclusion, β1-integrin is a potential factor for forming a prognosis following surgical resection in colorectal cancer patients. β1-Integrin may be a candidate for use as a marker for early detection of micrometastatic tumor cells and for monitoring the therapeutic response in colorectal cancer patients. PMID:24851215

  8. Involvement of lymphocyte function-associated antigen-1 (LFA-1) in HIV infection: inhibition by monoclonal antibody

    DEFF Research Database (Denmark)

    Hansen, J E; Nielsen, C; Mathiesen, Lars Reinhardt

    1991-01-01

    Monoclonal antibodies (MAbs) against the alpha- and beta-chain of lymphocyte-associated antigen-1 (LFA-1) were examined for inhibition of HIV-1 infection in vitro. Infection of the T cell line MT4 and the monocytic cell line U937 by isolates HTLVIIIB and SSI-002, respectively was inhibited...

  9. Mechanisms of integrin-vascular endothelial growth factor receptor cross-activation in angiogenesis.

    Science.gov (United States)

    Mahabeleshwar, Ganapati H; Feng, Weiyi; Reddy, Kumar; Plow, Edward F; Byzova, Tatiana V

    2007-09-14

    The functional responses of endothelial cells are dependent on signaling from peptide growth factors and the cellular adhesion receptors, integrins. These include cell adhesion, migration, and proliferation, which, in turn, are essential for more complex processes such as formation of the endothelial tube network during angiogenesis. This study identifies the molecular requirements for the cross-activation between beta3 integrin and tyrosine kinase receptor 2 for vascular endothelial growth factor (VEGF) receptor (VEGFR-2) on endothelium. The relationship between VEGFR-2 and beta3 integrin appears to be synergistic, because VEGFR-2 activation induces beta3 integrin tyrosine phosphorylation, which, in turn, is crucial for VEGF-induced tyrosine phosphorylation of VEGFR-2. We demonstrate here that adhesion- and growth factor-induced beta3 integrin tyrosine phosphorylation are directly mediated by c-Src. VEGF-stimulated recruitment and activation of c-Src and subsequent beta3 integrin tyrosine phosphorylation are critical for interaction between VEGFR-2 and beta3 integrin. Moreover, c-Src mediates growth factor-induced beta3 integrin activation, ligand binding, beta3 integrin-dependent cell adhesion, directional migration of endothelial cells, and initiation of angiogenic programming in endothelial cells. Thus, the present study determines the molecular mechanisms and consequences of the synergism between 2 cell surface receptor systems, growth factor receptor and integrins, and opens new avenues for the development of pro- and antiangiogenic strategies.

  10. Zebrafish integrin-linked kinase is required in skeletal muscles for strengthening the integrin-ECM adhesion complex.

    NARCIS (Netherlands)

    Postel, R.; Vakeel, P.; Topczewski, J.; Knoll, R.; Bakkers, J.

    2008-01-01

    Mechanical instability of skeletal muscle cells is the major cause of congenital muscular dystrophy. Here we show that the zebrafish lost-contact mutant, that lacks a functional integrin-linked kinase (ilk) gene, suffers from mechanical instability of skeletal muscle fibres. With genetic and

  11. Frontline Science: Functionally impaired geriatric CAR-T cells rescued by increased α5β1 integrin expression.

    Science.gov (United States)

    Guha, Prajna; Cunetta, Marissa; Somasundar, Ponnandai; Espat, N Joseph; Junghans, Richard P; Katz, Steven C

    2017-08-01

    Chimeric antigen receptor expressing T cells (CAR-T) are a promising form of immunotherapy, but the influence of age-related immune changes on CAR-T production remains poorly understood. We showed that CAR-T cells from geriatric donors (gCAR-T) are functionally impaired relative to CAR-T from younger donors (yCAR-T). Higher transduction efficiencies and improved cell expansion were observed in yCAR-T cells compared with gCAR-T. yCAR-T demonstrated significantly increased levels of proliferation and signaling activation of phosphorylated (p)Erk, pAkt, pStat3, and pStat5. Furthermore, yCAR-T contained higher proportions of CD4 and CD8 effector memory (EM) cells, which are known to have enhanced cytolytic capabilities. Accordingly, yCAR-T demonstrated higher levels of tumor antigen-specific cytotoxicity compared with gCAR-T. Enhanced tumor killing by yCAR-T correlated with increased levels of perforin and granzyme B. yCAR-T had increased α5β1 integrin expression, a known mediator of retroviral transduction. We found that treatment with M-CSF or TGF-β1 rescued the impaired transduction efficiency of the gCAR-T by increasing the α5β1 integrin expression. Neutralization of α5β1 confirmed that this integrin was indispensable for CAR expression. Our study suggests that the increase of α5β1 integrin expression levels enhances CAR expression and thereby improves tumor killing by gCAR-T. © Society for Leukocyte Biology.

  12. Electric Signals Regulate the Directional Migration of Oligodendrocyte Progenitor Cells (OPCs via β1 Integrin

    Directory of Open Access Journals (Sweden)

    Bangfu Zhu

    2016-11-01

    Full Text Available The guided migration of neural cells is essential for repair in the central nervous system (CNS. Oligodendrocyte progenitor cells (OPCs will normally migrate towards an injury site to re-sheath demyelinated axons; however the mechanisms underlying this process are not well understood. Endogenous electric fields (EFs are known to influence cell migration in vivo, and have been utilised in this study to direct the migration of OPCs isolated from neonatal Sprague-Dawley rats. The OPCs were exposed to physiological levels of electrical stimulation, and displayed a marked electrotactic response that was dependent on β1 integrin, one of the key subunits of integrin receptors. We also observed that F-actin, an important component of the cytoskeleton, was re-distributed towards the leading edge of the migrating cells, and that this asymmetric rearrangement was associated with β1 integrin function.

  13. Endothelial cell-derived matrix promotes the metabolic functional maturation of hepatocyte via integrin-Src signalling.

    Science.gov (United States)

    Guo, Xinyue; Li, Weihong; Ma, Minghui; Lu, Xin; Zhang, Haiyan

    2017-11-01

    The extracellular matrix (ECM) microenvironment is involved in the regulation of hepatocyte phenotype and function. Recently, the cell-derived extracellular matrix has been proposed to represent the bioactive and biocompatible materials of the native ECM. Here, we show that the endothelial cell-derived matrix (EC matrix) promotes the metabolic maturation of human adipose stem cell-derived hepatocyte-like cells (hASC-HLCs) through the activation of the transcription factor forkhead box protein A2 (FOXA2) and the nuclear receptors hepatocyte nuclear factor 4 alpha (HNF4α) and pregnane X receptor (PXR). Reducing the fibronectin content in the EC matrix or silencing the expression of α5 integrin in the hASC-HLCs inhibited the effect of the EC matrix on Src phosphorylation and hepatocyte maturation. The inhibition of Src phosphorylation using the inhibitor PP2 or silencing the expression of Src in hASC-HLCs also attenuated the up-regulation of the metabolic function of hASC-HLCs in a nuclear receptor-dependent manner. These data elucidate integrin-Src signalling linking the extrinsic EC matrix signals and metabolic functional maturation of hepatocyte. This study provides a model for studying the interaction between hepatocytes and non-parenchymal cell-derived matrix. © 2017 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

  14. Oncofetal Chondroitin Sulfate Glycosaminoglycans Are Key Players in Integrin Signaling and Tumor Cell Motility.

    Science.gov (United States)

    Clausen, Thomas Mandel; Pereira, Marina Ayres; Al Nakouzi, Nader; Oo, Htoo Zarni; Agerbæk, Mette Ø; Lee, Sherry; Ørum-Madsen, Maj Sofie; Kristensen, Anders Riis; El-Naggar, Amal; Grandgenett, Paul M; Grem, Jean L; Hollingsworth, Michael A; Holst, Peter J; Theander, Thor; Sorensen, Poul H; Daugaard, Mads; Salanti, Ali

    2016-12-01

    Many tumors express proteoglycans modified with oncofetal chondroitin sulfate glycosaminoglycan chains (ofCS), which are normally restricted to the placenta. However, the role of ofCS in cancer is largely unknown. The function of ofCS in cancer was analyzed using the recombinant ofCS-binding VAR2CSA protein (rVAR2) derived from the malaria parasite, Plasmodium falciparum We demonstrate that ofCS plays a key role in tumor cell motility by affecting canonical integrin signaling pathways. Binding of rVAR2 to tumor cells inhibited the interaction of cells with extracellular matrix (ECM) components, which correlated with decreased phosphorylation of Src kinase. Moreover, rVAR2 binding decreased migration, invasion, and anchorage-independent growth of tumor cells in vitro Mass spectrometry of ofCS-modified proteoglycan complexes affinity purified from tumor cell lines on rVAR2 columns revealed an overrepresentation of proteins involved in cell motility and integrin signaling, such as integrin-β1 (ITGB1) and integrin-α4 (ITGA4). Saturating concentrations of rVAR2 inhibited downstream integrin signaling, which was mimicked by knockdown of the core chondroitin sulfate synthesis enzymes β-1,3-glucuronyltransferase 1 (B3GAT1) and chondroitin sulfate N-acetylgalactosaminyltransferase 1 (CSGALNACT1). The ofCS modification was highly expressed in both human and murine metastatic lesions in situ and preincubation or early intravenous treatment of tumor cells with rVAR2 inhibited seeding and spreading of tumor cells in mice. This was associated with a significant increase in survival of the animals. These data functionally link ofCS modifications with cancer cell motility and further highlights ofCS as a novel therapeutic cancer target. The cancer-specific expression of ofCS aids in metastatic phenotypes and is a candidate target for therapy. Mol Cancer Res; 14(12); 1288-99. ©2016 AACR. ©2016 American Association for Cancer Research.

  15. Targeting of alpha-v integrins reduces malignancy of bladder carcinoma.

    Directory of Open Access Journals (Sweden)

    Geertje van der Horst

    Full Text Available Low survival rates of metastatic cancers emphasize the need for a drug that can prevent and/or treat metastatic cancer. αv integrins are involved in essential processes for tumor growth and metastasis and targeting of αv integrins has been shown to decrease angiogenesis, tumor growth and metastasis. In this study, the role of αv integrin and its potential as a drug target in bladder cancer was investigated. Treatment with an αv integrin antagonist as well as knockdown of αv integrin in the bladder carcinoma cell lines, resulted in reduced malignancy in vitro, as illustrated by decreased proliferative, migratory and clonogenic capacity. The CDH1/CDH2 ratio increased, indicating a shift towards a more epithelial phenotype. This shift appeared to be associated with downregulation of EMT-inducing transcription factors including SNAI2. The expression levels of the self-renewal genes NANOG and BMI1 decreased as well as the number of cells with high Aldehyde Dehydrogenase activity. In addition, self-renewal ability decreased as measured with the urosphere assay. In line with these observations, knockdown or treatment of αv integrins resulted in decreased metastatic growth in preclinical in vivo models as assessed by bioluminescence imaging. In conclusion, we show that αv integrins are involved in migration, EMT and maintenance of Aldehyde Dehydrogenase activity in bladder cancer cells. Targeting of αv integrins might be a promising approach for treatment and/or prevention of metastatic bladder cancer.

  16. Different Phenotypes in Human Prostate Cancer: α6 or α3 Integrin in Cell-extracellular Adhesion Sites

    Directory of Open Access Journals (Sweden)

    Monika Schmelz

    2002-01-01

    Full Text Available The distribution of α6/α3 integrin in adhesion complexes at the basal membrane in human normal and cancer prostate glands was analyzed in 135 biopsies from 61 patients. The levels of the polarized α6/α3 integrin expression at the basal membrane of prostate tumor glands were determined by quantitative immunohistochemistry. The α6/α3 integrin expression was compared with Gleason sum score, pathological stage, and preoperative serum prostate-specific antigen (PSA. The associations were assessed by statistical methods. Eighty percent of the tumors expressed the α6 or α3 integrin and 20% was integrin-negative. Gleason sum score, but not serum PSA, was associated with the integrin expression. Low Gleason sum score correlated with increased integrin expression, high Gleason sum score with low and negative integrin expression. Three prostate tumor phenotypes were distinguished based on differential integrin expression. Type I coexpressed both α6 and α3 subunits, type II exclusively expressed a6 integrin, and type III expressed α3 integrin only. Fifteen cases were further examined for the codistribution of vinculin, paxillin, and CD 151 on frozen serial sections using confocal laser scanning microscopy. The α6/α3 integrins, CD151, paxillin, and vinculin were present within normal glands. In prostate carcinoma, α6 integrin was colocalized with CD 151, but not with vinculin or paxillin. In tumor phenotype I, the α6 subunit did not colocalize with the α3 subunit indicating the existence of two different adhesion complexes. Human prostate tumors display on their cell surface the α6β1 and/or α3β1 integrins. Three tumor phenotypes associated with two different adhesion complexes were identified, suggesting a reorganization of cell adhesion structures in prostate cancer.

  17. Integrin beta3 Leu33Pro polymorphism and risk of hip fracture: 25 years follow-up of 9233 adults from the general population

    DEFF Research Database (Denmark)

    Tofteng, Charlotte L; Bach-Mortensen, Pernille; Bojesen, Stig E

    2007-01-01

    OBJECTIVE: Integrin alphavbeta3 is essential for mature osteoclast function and therefore important for the development of osteoporosis and osteoporotic fractures. Integrin alphavbeta3 antagonists have antiresorptive effects in bone. We tested the hypothesis that the Leu33Pro polymorphism...... in the integrin beta3-subunit associates with risk of hip fracture. METHODS: We included 9233 men and women selected at random to represent the Danish general population as participants in the Copenhagen City Heart Study. First-ever hip fractures (n=267) were registered during 25 years follow-up. Log...

  18. Isthmin exerts pro-survival and death-promoting effect on endothelial cells through alphavbeta5 integrin depending on its physical state.

    Science.gov (United States)

    Zhang, Y; Chen, M; Venugopal, S; Zhou, Y; Xiang, W; Li, Y-H; Lin, Q; Kini, R M; Chong, Y-S; Ge, R

    2011-05-05

    Isthmin (ISM) is a 60 kDa secreted-angiogenesis inhibitor that suppresses tumor growth in mouse and disrupts vessel patterning in zebrafish embryos. It selectively binds to alphavbeta5 (αvβ5) integrin on the surface of endothelial cells (ECs), but the mechanism of its antiangiogenic action remains unknown. In this work, we establish that soluble ISM suppresses in vitro angiogenesis and induces EC apoptosis by interacting with its cell surface receptor αvβ5 integrin through a novel 'RKD' motif localized within its adhesion-associated domain in MUC4 and other proteins domain. ISM induces EC apoptosis through integrin-mediated death (IMD) by direct recruitment and activation of caspase-8 without causing anoikis. On the other hand, immobilized ISM loses its antiangiogenic function and instead promotes EC adhesion, survival and migration through αvβ5 integrin by activating focal adhesion kinase (FAK). ISM unexpectedly has both a pro-survival and death-promoting effect on ECs depending on its physical state. This dual function of a single antiangiogenic protein may impact its antiangiogenic efficacy in vivo.

  19. Integrin-like proteins are localized to plasma membrane fractions, not plastids, in Arabidopsis

    Science.gov (United States)

    Swatzell, L. J.; Edelmann, R. E.; Makaroff, C. A.; Kiss, J. Z.

    1999-01-01

    Integrins are a large family of integral membrane proteins that function in signal transduction in animal systems. These proteins are conserved in vertebrates, invertebrates, and fungi. Evidence from previous research suggests that integrin-like proteins may be present in plants as well, and that these proteins may function in signal transduction during gravitropism. In past studies, researchers have used monoclonal and polyclonal antibodies to localize beta 1 integrin-like proteins in plants. However, there is a disparity between data collected from these studies, especially since molecular weights obtained from these investigations range from 55-120 kDa for integrin-like proteins. To date, a complete investigation which employs all three basic immunolabeling procedures, immunoblotting, immunofluorescence microscopy, and immunogold labeling, in addition to extensive fractionation and exhaustive controls, has been lacking. In this paper, we demonstrate that use of a polyclonal antibody against the cytoplasmic domain of avian beta 1-integrin can produce potential artifacts in immunolocalization studies. However, these problems can be eliminated through use of starchless mutants or proper specimen preparation prior to electrophoresis. We also show that this antibody, when applied within the described parameters and with careful controls, identifies a large (100 kDa) integrin-like protein that is localized to plasma membrane fractions in Arabidopsis.

  20. Outside-In Signal Transmission by Conformational Changes in Integrin Mac-11

    Science.gov (United States)

    Lefort, Craig T.; Hyun, Young-Min; Schultz, Joanne B.; Law, Foon-Yee; Waugh, Richard E.; Knauf, Philip A.; Kim, Minsoo

    2010-01-01

    Intracellular signals associated with or triggered by integrin ligation can control cell survival, differentiation, proliferation, and migration. Despite accumulating evidence that conformational changes regulate integrin affinity to its ligands, how integrin structure regulates signal transmission from the outside to the inside of the cell remains elusive. Using fluorescence resonance energy transfer, we addressed whether conformational changes in integrin Mac-1 are sufficient to transmit outside-in signals in human neutrophils. Mac-1 conformational activation induced by ligand occupancy or activating Ab binding, but not integrin clustering, triggered similar patterns of intracellular protein tyrosine phosphorylation, including Akt phosphorylation, and inhibited spontaneous neutrophil apoptosis, indicating that global conformational changes are critical for Mac-1-dependent outside-in signal transduction. In neutrophils and myeloid K562 cells, ligand ICAM-1 or activating Ab binding promoted switchblade-like extension of the Mac-1 extracellular domain and separation of the αM and β2 subunit cytoplasmic tails, two structural hallmarks of integrin activation. These data suggest the primacy of global conformational changes in the generation of Mac-1 outside-in signals. PMID:19864611

  1. Integrin Signalling

    OpenAIRE

    Schelfaut, Roselien

    2005-01-01

    Integrins are receptors presented on most cells. By binding ligand they can generate signalling pathways inside the cell. Those pathways are a linkage to proteins in the cytosol. It is known that tumor cells can survive and proliferate in the absence of a solid support while normal cells need to be bound to ligand. To understand why tumour cells act that way, we first have to know how ligand-binding to integrins affect the cell. This research field includes studies on activation of proteins b...

  2. EMMPRIN regulates β1 integrin-mediated adhesion through Kindlin-3 in human melanoma cells.

    Science.gov (United States)

    Delyon, Julie; Khayati, Farah; Djaafri, Ibtissem; Podgorniak, Marie-Pierre; Sadoux, Aurélie; Setterblad, Niclas; Boutalbi, Zineb; Maouche, Kamel; Maskos, Uwe; Menashi, Suzanne; Lebbé, Céleste; Mourah, Samia

    2015-06-01

    EMMPRIN is known to promote tumor invasion through extracellular matrix (ECM) degradation. Here we report that EMMPRIN can regulate melanoma cell adhesion to the ECM through an interaction with β1 integrin involving kindlin-3. In this study, EMMPRIN knockdown in the human melanoma cell line M10 using siRNA decreased cell invasion and significantly increased cell adhesion and spreading. A morphological change from a round to a spread shape was observed associated with enhanced phalloidin-labelled actin staining. In situ proximity ligation assay and co-immunoprecipitation revealed that EMMPRIN silencing increased the interaction of β1 integrin with kindlin-3, a focal adhesion protein. This was associated with an increase in β1 integrin activation and a decrease in the phosphorylation of the downstream integrin kinase FAK. Moreover, the expression at both the transcript and protein level of kindlin-3 and of β1 integrin was inversely regulated by EMMPRIN. EMMPRIN did not regulate either talin expression or its interaction with β1 integrin. These results are consistent with our in vivo demonstration that EMMPRIN inhibition increased β1 integrin activation and its interaction with kindlin-3. To conclude, these findings reveal a new role of EMMPRIN in tumor cell migration through ß1 integrin/kindlin-3-mediated adhesion pathway. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  3. Applications of snake venom components to modulate integrin activities in cell-matrix interactions

    Science.gov (United States)

    Marcinkiewicz, Cezary

    2013-01-01

    Snake venom proteins are broadly investigated in the different areas of life science. Direct interaction of these compounds with cells may involve a variety of mechanisms that result in diverse cellular responses leading to the activation or blocking of physiological functions of the cell. In this review, the snake venom components interacting with integrins will be characterized in context of their effect on cellular response. Currently, two major families of snake venom proteins are considered as integrin-binding molecules. The most attention has been devoted to the disintegrin family, which binds certain types of integrins through specific motifs recognized as a tri-peptide structurally localized on an integrin-binding loop. Other snake venom integrin-binding proteins belong to the C-type lectin family. Snake venom molecules bind to the cellular integrins resulting in a modulation of cell signaling and in consequence, the regulation of cell proliferation, migration and apoptosis. Therefore, snake venom research on the integrin-binding molecules may have significance in biomedicine and basic cell biology. PMID:23811033

  4. Genetic Variability in Platelet Integrin α2β1 Density: Possible Contributor to Plasmodium vivax–induced Severe Thrombocytopenia

    Science.gov (United States)

    Campos, Fernanda M. F.; Santos, Marina L. S.; Kano, Flora S.; Fontes, Cor J. F.; Lacerda, Marcus V. G.; Brito, Cristiana F. A.; Carvalho, Luzia H.

    2013-01-01

    Understanding the pathogenesis of Plasmodium vivax malaria is challenging. We hypothesized that susceptibility to P. vivax-induced thrombocytopenia could be associated with polymorphisms on relevant platelet membrane integrins: integrin α2 (C807T), and integrin β3 (T1565C). Although β3 polymorphism was not related with P. vivax malaria, α2 807T carriers, which show high levels of integrin α2β1, had a higher probability for severe thrombocytopenia than wild-type carriers. This evidence of the association of integrin polymorphism and P. vivax morbidity was further demonstrated by a moderate but significant correlation between clinical disease and surface levels of the integrin α2β1. PMID:23249684

  5. ADAM12 induces actin cytoskeleton and extracellular matrix reorganization during early adipocyte differentiation by regulating beta1 integrin function

    DEFF Research Database (Denmark)

    Kawaguchi, Nobuko; Sundberg, Christina; Kveiborg, Marie

    2003-01-01

    -100 from cells overexpressing ADAM12 than from control cells. Collectively, these results show that surface expression of ADAM12 impairs the function of beta1 integrins and, consequently, alters the organization of the actin cytoskeleton and extracellular matrix. These events may be necessary...

  6. Coalition of Oct4A and β1 integrins in facilitating metastasis in ovarian cancer

    International Nuclear Information System (INIS)

    Samardzija, Chantel; Luwor, Rodney B.; Quinn, Michael A.; Kannourakis, George; Findlay, Jock K.; Ahmed, Nuzhat

    2016-01-01

    Ovarian cancer is a metastatic disease and one of the leading causes of gynaecology malignancy-related deaths in women. Cancer stem cells (CSCs) are key contributors of cancer metastasis and relapse. Integrins are a family of cell surface receptors which allow interactions between cells and their surrounding microenvironment and play a fundamental role in promoting metastasis. This study investigates the molecular mechanism which associates CSCs and integrins in ovarian cancer metastasis. The expression of Oct4A in high-grade serous ovarian tumors and normal ovaries was determined by immunofluorescence analysis. The functional role of Oct4A was evaluated by generating stable knockdown (KD) of Oct4A clones in an established ovarian cancer cell line HEY using shRNA-mediated silencing. The expression of integrins in cell lines was evaluated by flow cytometry. Spheroid forming ability, adhesion and the activities of matrix metalloproteinases 9/2 (MMP-9/2) was measured by in vitro functional assays and gelatin zymography. These observations were further validated in in vivo mouse models using Balb/c nu/nu mice. We report significantly elevated expression of Oct4A in high-grade serous ovarian tumors compared to normal ovarian tissues. The expression of Oct4A in ovarian cancer cell lines correlated with their CSC-related sphere forming abilities. The suppression of Oct4A in HEY cells resulted in a significant diminution of integrin β1 expression and associated α5 and α2 subunits compared to vector control cells. This was associated with a reduced adhesive ability on collagen and fibronectin and decreased secretion of pro-MMP2 in Oct4A KD cells compared to vector control cells. In vivo, Oct4A knock down (KD) cells produced tumors which were significantly smaller in size and weight compared to tumors derived from vector control cells. Immunohistochemical analyses of Oct4A KD tumor xenografts demonstrated a significant loss of cytokeratin 7 (CK7), Glut-1 as well as CD34

  7. The Integrin Receptor in Biologically Relevant Bilayers

    DEFF Research Database (Denmark)

    Kalli, Antreas C.; Róg, Tomasz; Vattulainen, Ilpo

    2017-01-01

    /talin complex was inserted in biologically relevant bilayers that resemble the cell plasma membrane containing zwitterionic and charged phospholipids, cholesterol and sphingolipids to study the dynamics of the integrin receptor and its effect on bilayer structure and dynamics. The results of this study...... demonstrate the dynamic nature of the integrin receptor and suggest that the presence of the integrin receptor alters the lipid organization between the two leaflets of the bilayer. In particular, our results suggest elevated density of cholesterol and of phosphatidylserine lipids around the integrin....../talin complex and a slowing down of lipids in an annulus of ~30 Å around the protein due to interactions between the lipids and the integrin/talin F2–F3 complex. This may in part regulate the interactions of integrins with other related proteins or integrin clustering thus facilitating signal transduction...

  8. Angiotensin converting enzyme (ACE and ACE2 bind integrins and ACE2 regulates integrin signalling.

    Directory of Open Access Journals (Sweden)

    Nicola E Clarke

    Full Text Available The angiotensin converting enzymes (ACEs are the key catalytic components of the renin-angiotensin system, mediating precise regulation of blood pressure by counterbalancing the effects of each other. Inhibition of ACE has been shown to improve pathology in cardiovascular disease, whilst ACE2 is cardioprotective in the failing heart. However, the mechanisms by which ACE2 mediates its cardioprotective functions have yet to be fully elucidated. Here we demonstrate that both ACE and ACE2 bind integrin subunits, in an RGD-independent manner, and that they can act as cell adhesion substrates. We show that cellular expression of ACE2 enhanced cell adhesion. Furthermore, we present evidence that soluble ACE2 (sACE2 is capable of suppressing integrin signalling mediated by FAK. In addition, sACE2 increases the expression of Akt, thereby lowering the proportion of the signalling molecule phosphorylated Akt. These results suggest that ACE2 plays a role in cell-cell interactions, possibly acting to fine-tune integrin signalling. Hence the expression and cleavage of ACE2 at the plasma membrane may influence cell-extracellular matrix interactions and the signalling that mediates cell survival and proliferation. As such, ectodomain shedding of ACE2 may play a role in the process of pathological cardiac remodelling.

  9. Lumican alleviates hypertrophic scarring by suppressing integrin-FAK signaling

    International Nuclear Information System (INIS)

    Zhao, Yuqian; Li, Xueyong; Xu, Xiaoli; He, Zhi; Cui, Lei; Lv, Xiaoxing

    2016-01-01

    Hypertrophic scarring (HS) is an overcompensation of wound healing that increases the risk of cosmetic disfigurement and functional impairment. No gold standard has been established for the treatment or prevention of HS. Our study aims to elucidate the expression and function of lumican in the pathogenesis of HS as well as the underlying mechanism involved in this procedure. An animal model of HS (rabbit ear) was established, and the Ad-lumican vectors were locally injected. Primary fibroblasts isolated from patients with hypertrophic burn scars were used in vitro. Histological and molecular changes in HS pathogenesis were evaluated. The results showed that lumican is significantly reduced in HS tissues and fibroblasts from HS patients as compared to normal skin or cells. Lumican levels were further suppressed in response to TGF-β stimulation. However, lumican upregulation effectively thinned the scar area and inhibited fibroblast proliferation and the cell cycle. Meanwhile, Ad-lumican administration suppressed the deposition of extracellular matrix, such as collagen and CTGF. Ad-lumican injected animals or fibroblasts presented comparable integrin α 2 β 1 expression while greatly reduced phosphorylation of FAK compared to the negative control. Moreover, Ad-lumican administration largely enhanced the binding of lumican to integrin α 2 β 1 and may thus inhibit the signaling propagation of collagen-integrin α 2 β 1 . Overall, the restoration of lumican levels contributed to suppressing the HS progression by inhibiting collagen-integrin α 2 β 1 -FAK signaling. - Highlights: • Lumican is downregulated during hypertrophic scar formation. • Lumican inhibits fibroblast proliferation. • Lumican inhibits extracellular matrix deposition. • Lumican suppresses collagen-integrin-FAK signaling.

  10. Oncofetal Chondroitin Sulfate Glycosaminoglycans are Key Players in Integrin Signaling and Tumor Cell Motility

    Science.gov (United States)

    Clausen, Thomas Mandel; Pereira, Marina Ayres; Al Nakouzi, Nader; Oo, Htoo Zarni; Agerbæk, Mette Ø; Lee, Sherry; Ørum-Madsen, Maj Sofie; Christensen, Anders Riis; El-Naggar, Amal; Grandgenett, Paul M.; Grem, Jean L.; Hollingsworth, Michael A.; Holst, Peter J.; Theander, Thor; Sorensen, Poul H.; Daugaard, Mads; Salanti, Ali

    2016-01-01

    Many tumors express proteoglycans modified with oncofetal chondroitin sulfate glycosaminoglycan chains (ofCS), which are normally restricted to the placenta. However, the role of ofCS in cancer is largely unknown. The function of ofCS in cancer was analyzed using the recombinant ofCS-binding VAR2CSA protein (rVAR2) derived from the malaria parasite, Plasmodium falciparum. We demonstrate that ofCS plays a key role in tumor cell motility by affecting canonical integrin signaling pathways. Binding of rVAR2 to tumor cells inhibited the interaction of cells with extracellular matrix (ECM) components, which correlated with decreased phosphorylation of Src kinase. Moreover, rVAR2 binding decreased migration, invasion and anchorage-independent growth of tumor cells in vitro. Mass spectrometry of ofCS-modified proteoglycan complexes affinity purified from tumor cell lines on rVAR2 columns, revealed an overrepresentation of proteins involved in cell motility and integrin signaling, such as integrin β1 (ITGB1) and integrin α4 (ITGA4). Saturating concentrations of rVAR2 inhibited downstream integrin signaling, which was mimicked by knockdown of the core CS synthesis enzymes Beta-1,3-Glucuronyltransferase 1 (B3GAT1) and Chondroitin Sulfate N-Acetylgalactosaminyltransferase 1 (CSGALNACT1). The ofCS modification was highly expressed in both human and murine metastatic lesions in situ and pre-incubation or early intravenous treatment of tumor cells with rVAR2 inhibited seeding and spreading of tumor cells in mice. This was associated with a significant increase in survival of the animals. These data functionally link ofCS modifications with cancer cell motility and further highlights ofCS as a novel therapeutic cancer target. Implications The cancer specific expression of oncofetal chondroitin sulfate aids in metastatic phenotypes and is a candidate target for therapy. PMID:27655130

  11. Polarization of the epithelial layer and apical localization of integrins are required for engulfment of apoptotic cells in the Drosophila ovary

    Directory of Open Access Journals (Sweden)

    Tracy L. Meehan

    2015-12-01

    Full Text Available Inefficient clearance of dead cells or debris by epithelial cells can lead to or exacerbate debilitating conditions such as retinitis pigmentosa, macular degeneration, chronic obstructive pulmonary disease and asthma. Despite the importance of engulfment by epithelial cells, little is known about the molecular changes that are required within these cells. The misregulation of integrins has previously been associated with disease states, suggesting that a better understanding of the regulation of receptor trafficking could be key to treating diseases caused by defects in phagocytosis. Here, we demonstrate that the integrin heterodimer αPS3/βPS becomes apically enriched and is required for engulfment by the epithelial follicle cells of the Drosophila ovary. We found that integrin heterodimer localization and function is largely directed by the α-subunit. Moreover, proper cell polarity promotes asymmetric integrin enrichment, suggesting that αPS3/βPS trafficking occurs in a polarized fashion. We show that several genes previously known for their roles in trafficking and cell migration are also required for engulfment. Moreover, as in mammals, the same α-integrin subunit is required by professional and non-professional phagocytes and migrating cells in Drosophila. Our findings suggest that migrating and engulfing cells use common machinery, and demonstrate a crucial role for integrin function and polarized trafficking of integrin subunits during engulfment. This study also establishes the epithelial follicle cells of the Drosophila ovary as a powerful model for understanding the molecular changes required for engulfment by a polarized epithelium.

  12. Measurement of exercise-induced oxidative stress in lymphocytes.

    Science.gov (United States)

    Turner, James E; Bosch, Jos A; Aldred, Sarah

    2011-10-01

    Vigorous exercise is associated with oxidative stress, a state that involves modifications to bodily molecules due to release of pro-oxidant species. Assessment of such modifications provides non-specific measures of oxidative stress in human tissues and blood, including circulating lymphocytes. Lymphocytes are a very heterogeneous group of white blood cells, consisting of subtypes that have different functions in immunity. Importantly, exercise drastically changes the lymphocyte composition in blood by increasing the numbers of some subsets, while leaving other cells unaffected. This fact may imply that observed changes in oxidative stress markers are confounded by changes in lymphocyte composition. For example, lymphocyte subsets may differ in exposure to oxidative stress because of subset differences in cell division and the acquisition of cytotoxic effector functions. The aim of the present review is to raise awareness of interpretational issues related to the assessment of oxidative stress in lymphocytes with exercise and to address the relevance of lymphocyte subset phenotyping in these contexts.

  13. Signaling triggered by Thy-1 interaction with ß3 integrin on astrocytes is an essential step towards unraveling neuronal Thy-1 function

    Directory of Open Access Journals (Sweden)

    ANA MARIA AVALOS

    2002-01-01

    Full Text Available Thy-1 is an abundant neuronal glycoprotein in mammals. Despite such prevalence, Thy-1 function remains largely obscure in the absence of a defined ligand. Recently described evidence that Thy-1 interacts with ß3 integrin on astrocytes will be discussed. Thy-1 binding to ß3 integrin triggers tyrosine phosphorylation of focal adhesion proteins in astrocytes, thereby promoting focal adhesion formation, cell attachment and spreading. Thy-1 has been reported to modulate neurite outgrowth by triggering a cellular response in neurons. However, our data indicate that Thy-1 can also initiate signaling events that promote adhesion of adjacent astrocytes to the underlying surface. Preliminary results suggest that morphological changes observed in the actin cytoskeleton of astrocytes as a consequence of Thy-1 binding is mediated by small GTPases from the Rho family. Our findings argue that Thy-1 functions in a bimodal fashion, as a receptor on neuronal cells and as a ligand for ß3 integrin receptor on astrocytes. Since Thy-1 is implicated in the inhibition of neurite outgrowth, signaling events in astrocytes are likely to play an important role in this process

  14. 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

    Science.gov (United States)

    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

  15. Stable coordination of the inhibitory Ca2+ ion at MIDAS in integrin CD11b/CD18 by an antibody-derived ligand aspartate: Implications for integrin regulation and structure-based drug design

    Science.gov (United States)

    Mahalingam, Bhuvaneshwari; Ajroud, Kaouther; Alonso, Jose Luis; Anand, Saurabh; Adair, Brian; Horenstein, Alberto L; Malavasi, Fabio; Xiong, Jian-Ping; Arnaout, M. Amin

    2011-01-01

    A central feature of integrin interaction with physiologic ligands is the monodentate binding of a ligand carboxylate to a Mg2+ ion hexacoordinated at the metal-ion-dependent-adhesion site (MIDAS) in the integrin A-domain. This interaction stabilizes the A-domain in the high-affinity state, which is distinguished from the default low-affinity state by tertiary changes in the domain that culminate in cell adhesion. Small molecule ligand-mimetic integrin antagonists act as partial agonists, eliciting similar activating conformational changes in the A-domain, which has contributed to paradoxical adhesion and increased patient mortality in large clinical trials. As with other ligand-mimetic integrin antagonists, the function-blocking monoclonal antibody (mAb) 107 binds MIDAS of integrin CD11b/CD18 A-domain (CD11bA), but in contrast, it favors the inhibitory Ca2+ ion over Mg2+ at MIDAS. We determined the crystal structures of the Fab fragment of mAb 107 complexed to the low- and high-affinity states of CD11bA. Favored binding of Ca2+ at MIDAS is caused by the unusual symmetric bidentate ligation of a Fab-derived ligand Asp to a heptacoordinated MIDAS Ca2+. Binding of Fab 107 to CD11bA did not trigger the activating tertiary changes in the domain or in the full-length integrin. These data show that denticity of the ligand Asp/Glu can modify divalent cation selectivity at MIDAS and hence integrin function. Stabilizing the Ca2+ ion at MIDAS by bidentate ligation to a ligand Asp/Glu may provide one approach for designing pure integrin antagonists. PMID:22095715

  16. β1-integrin controls cell fate specification in early lens development

    Science.gov (United States)

    Pathania, Mallika; Wang, Yan; Simirskii, Vladimir N.; Duncan, Melinda K.

    2016-01-01

    Integrins are heterodimeric cell surface molecules that mediate cell-extracellular matrix (ECM) adhesion, ECM assembly, and regulation of both ECM and growth factor induced signaling. However, the developmental context of these diverse functions is not clear. Loss of β1-integrin from the lens vesicle (mouse E10.5) results in abnormal exit of anterior lens epithelial cells (LECs) from the cell cycle and their aberrant elongation toward the presumptive cornea by E12.5. These cells lose expression of LEC markers and initiate expression of the Maf (also known as c-Maf) and Prox1 transcription factors as well as other lens fiber cell markers, β1-integrin null LECs also upregulate the ERK, AKT and Smad1/5/8 phosphorylation indicative of BMP and FGF signaling. By E14.5, β1-integrin null lenses have undergone a complete conversion of all lens epithelial cells into fiber cells. These data suggest that shortly after lens vesicle closure, β1-integrin blocks inappropriate differentiation of the lens epithelium into fibers, potentially by inhibiting BMP and/or FGF receptor activation. Thus, β1-integrin has an important role in fine-tuning the response of the early lens to the gradient of growth factors that regulate lens fiber cell differentiation. PMID:27596755

  17. Loss of ADAM9 expression impairs β1 integrin endocytosis, focal adhesion formation and cancer cell migration

    DEFF Research Database (Denmark)

    Mygind, Kasper J; Schwarz, Jeanette; Sahgal, Pranshu

    2018-01-01

    knockdown increases β1 integrin levels through mechanisms that are independent of its protease activity. In ADAM9-silenced cells, adhesion to collagen and fibronectin is reduced, suggesting an altered function of the accumulated integrins. Mechanistically, ADAM9 co-immunoprecipitates with β1 integrin......, and both internalization and subsequent degradation of β1 integrin are significantly decreased in ADAM9-silenced cells, with no effect on β1 integrin recycling. Accordingly, the formation of focal adhesions and actin stress fibres in ADAM9-silenced cells is altered, possibly explaining the reduction...

  18. Sequence-specific interaction between the disintegrin domain of mouse ADAM 3 and murine eggs: role of beta1 integrin-associated proteins CD9, CD81, and CD98.

    Science.gov (United States)

    Takahashi, Y; Bigler, D; Ito, Y; White, J M

    2001-04-01

    ADAM 3 is a sperm surface glycoprotein that has been implicated in sperm-egg adhesion. Because little is known about the adhesive activity of ADAMs, we investigated the interaction of ADAM 3 disintegrin domains, made in bacteria and in insect cells, with murine eggs. Both recombinant proteins inhibited sperm-egg binding and fusion with potencies similar to that which we recently reported for the ADAM 2 disintegrin domain. Alanine scanning mutagenesis revealed a critical importance for the glutamine at position 7 of the disintegrin loop. Fluorescent beads coated with the ADAM 3 disintegrin domain bound to the egg surface. Bead binding was inhibited by an authentic, but not by a scrambled, peptide analog of the disintegrin loop. Bead binding was also inhibited by the function-blocking anti-alpha6 monoclonal antibody (mAb) GoH3, but not by a nonfunction blocking anti-alpha6 mAb, or by mAbs against either the alphav or beta3 integrin subunits. We also present evidence that in addition to the tetraspanin CD9, two other beta1-integrin-associated proteins, the tetraspanin CD81 as well as the single pass transmembrane protein CD98 are expressed on murine eggs. Antibodies to CD9 and CD98 inhibited in vitro fertilization and binding of the ADAM 3 disintegrin domain. Our findings are discussed in terms of the involvement of multiple sperm ADAMs and multiple egg beta1 integrin-associated proteins in sperm-egg binding and fusion. We propose that an egg surface "tetraspan web" facilitates fertilization and that it may do so by fostering ADAM-integrin interactions.

  19. Sequence-Specific Interaction between the Disintegrin Domain of Mouse ADAM 3 and Murine Eggs: Role of β1 Integrin-associated Proteins CD9, CD81, and CD98

    Science.gov (United States)

    Takahashi, Yuji; Bigler, Dora; Ito, Yasuhiko; White, Judith M.

    2001-01-01

    ADAM 3 is a sperm surface glycoprotein that has been implicated in sperm-egg adhesion. Because little is known about the adhesive activity of ADAMs, we investigated the interaction of ADAM 3 disintegrin domains, made in bacteria and in insect cells, with murine eggs. Both recombinant proteins inhibited sperm-egg binding and fusion with potencies similar to that which we recently reported for the ADAM 2 disintegrin domain. Alanine scanning mutagenesis revealed a critical importance for the glutamine at position 7 of the disintegrin loop. Fluorescent beads coated with the ADAM 3 disintegrin domain bound to the egg surface. Bead binding was inhibited by an authentic, but not by a scrambled, peptide analog of the disintegrin loop. Bead binding was also inhibited by the function-blocking anti-α6 monoclonal antibody (mAb) GoH3, but not by a nonfunction blocking anti-α6 mAb, or by mAbs against either the αv or β3 integrin subunits. We also present evidence that in addition to the tetraspanin CD9, two other β1-integrin-associated proteins, the tetraspanin CD81 as well as the single pass transmembrane protein CD98 are expressed on murine eggs. Antibodies to CD9 and CD98 inhibited in vitro fertilization and binding of the ADAM 3 disintegrin domain. Our findings are discussed in terms of the involvement of multiple sperm ADAMs and multiple egg β1 integrin-associated proteins in sperm-egg binding and fusion. We propose that an egg surface “tetraspan web” facilitates fertilization and that it may do so by fostering ADAM–integrin interactions. PMID:11294888

  20. The integrin-actin connection, an eternal love affair

    DEFF Research Database (Denmark)

    Brakebusch, Cord; Fässler, Reinhard

    2003-01-01

    Integrin receptors connect the extracellular matrix to the actin cytoskeleton. This interaction can be viewed as a cyclical liaison, which develops again and again at new adhesion sites only to cease at sites of de-adhesion. Recent work has demonstrated that multidomain proteins play crucial roles...... in the integrin-actin connection by providing a high degree of regulation adjusted to the needs of the cell. In this review we present several examples of this paradigm and with special emphasis on the ILK-PINCH-parvin complex, which amply demonstrates how structural and signalling functions are linked together....

  1. Small molecule antagonists of integrin receptors.

    Science.gov (United States)

    Perdih, A; Dolenc, M Sollner

    2010-01-01

    The complex and widespread family of integrin receptors is involved in numerous physiological processes, such as tissue remodeling, angiogenesis, development of the immune response and homeostasis. In addition, their key role has been elucidated in important pathological disorders such as cancer, cardiovascular diseases, osteoporosis, autoimmune and inflammatory diseases and in the pathogenesis of infectious diseases, making them highly important targets for modern drug design campaigns. In this review we seek to present a concise overview of the small molecule antagonists of this diverse and highly complex receptor family. Integrin antagonists are classified according to the targeted integrin receptor and are discussed in four sections. First we present the fibrinogen alpha(IIb)beta3 and the vitronectin alpha (V)beta(3) receptor antagonists. The remaining selective integrin antagonists are examined in the third section. The final section is dedicated to molecules with dual or multiple integrin activity. In addition, the use of antibodies and peptidomimetic approaches to modulate the integrin receptors are discussed, as well providing the reader with an overall appreciation of the field.

  2. Lymphocyte function following radium-223 therapy in patients with metastasized, castration-resistant prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Barsegian, Vahe; Moeckel, Daniel [Helios Kliniken, Institute of Nuclear Medicine, Schwerin (Germany); Mueller, Stefan P.; Bockisch, Andreas [University Hospital Essen, Department of Nuclear Medicine, Essen (Germany); Horn, Peter A.; Lindemann, Monika [University Hospital Essen, Institute for Transfusion Medicine, Essen (Germany)

    2017-02-15

    Therapy with the alpha-emitter radium-223 chloride ({sup 223}Ra) is an innovative therapeutic option in patients with metastasized, castration-resistant prostate cancer. However, radiotherapy can lead to hematopoietic toxicity. The aim of this study was to determine if {sup 223}Ra therapy induces an impairment of cellular antimicrobial immune responses. In 11 patients receiving {sup 223}Ra treatment, lymphocyte proliferation and the production of pro- and anti-inflammatory cytokines (interferon-γ and interleukin-10) were determined, using lymphocyte transformation testing and ELISpot, respectively. Lymphocyte function after stimulation with mitogens and microbial antigens was assessed prior to therapy and at day 1, 7 and 28 after therapy. Lymphocyte proliferation and the production of interferon-γ and interleukin-10 towards mitogens and antigens remained unchanged after therapy. Consistent with these in vitro data, we did not observe infectious complications after treatment. The results argue against an impairment of lymphocyte function after {sup 223}Ra therapy. Thus, immune responses against pathogens should remain unaffected. (orig.)

  3. Fetal and adult hematopoietic stem cells require beta1 integrin function for colonizing fetal liver, spleen, and bone marrow

    DEFF Research Database (Denmark)

    Potocnik, A J; Brakebusch, C; Fässler, R

    2000-01-01

    hematolymphoid differentiation potential in vitro and in fetal organ cultures but were unable to seed fetal and adult hematopoietic tissues. Adult beta1 integrin null HSCs isolated from mice carrying loxP-tagged beta1 integrin alleles and ablated for beta1 integrin expression by retroviral cre transduction......Homing of hematopoietic stem cells (HSCs) into hematopoietic organs is a prerequisite for the establishment of hematopoiesis during embryogenesis and after bone marrow transplantation. We show that beta1 integrin-deficient HSCs from the para-aortic splanchnopleura and the fetal blood had...

  4. Lymphocyte Glucose and Glutamine Metabolism as Targets of the Anti-Inflammatory and Immunomodulatory Effects of Exercise

    Directory of Open Access Journals (Sweden)

    Frederick Wasinski

    2014-01-01

    Full Text Available Glucose and glutamine are important energetic and biosynthetic nutrients for T and B lymphocytes. These cells consume both nutrients at high rates in a function-dependent manner. In other words, the pathways that control lymphocyte function and survival directly control the glucose and glutamine metabolic pathways. Therefore, lymphocytes in different functional states reprogram their glucose and glutamine metabolism to balance their requirement for ATP and macromolecule production. The tight association between metabolism and function in these cells was suggested to introduce the possibility of several pathologies resulting from the inability of lymphocytes to meet their nutrient demands under a given condition. In fact, disruptions in lymphocyte metabolism and function have been observed in different inflammatory, metabolic, and autoimmune pathologies. Regular physical exercise and physical activity offer protection against several chronic pathologies, and this benefit has been associated with the anti-inflammatory and immunomodulatory effects of exercise/physical activity. Chronic exercise induces changes in lymphocyte functionality and substrate metabolism. In the present review, we discuss whether the beneficial effects of exercise on lymphocyte function in health and disease are associated with modulation of the glucose and glutamine metabolic pathways.

  5. Galectin-3 induces clustering of CD147 and integrin-β1 transmembrane glycoprotein receptors on the RPE cell surface.

    Directory of Open Access Journals (Sweden)

    Claudia S Priglinger

    Full Text Available Proliferative vitreoretinopathy (PVR is a blinding disease frequently occurring after retinal detachment surgery. Adhesion, migration and matrix remodeling of dedifferentiated retinal pigment epithelial (RPE cells characterize the onset of the disease. Treatment options are still restrained and identification of factors responsible for the abnormal behavior of the RPE cells will facilitate the development of novel therapeutics. Galectin-3, a carbohydrate-binding protein, was previously found to inhibit attachment and spreading of retinal pigment epithelial cells, and thus bares the potential to counteract PVR-associated cellular events. However, the identities of the corresponding cell surface glycoprotein receptor proteins on RPE cells are not known. Here we characterize RPE-specific Gal-3 containing glycoprotein complexes using a proteomic approach. Integrin-β1, integrin-α3 and CD147/EMMPRIN, a transmembrane glycoprotein implicated in regulating matrix metalloproteinase induction, were identified as potential Gal-3 interactors on RPE cell surfaces. In reciprocal immunoprecipitation experiments we confirmed that Gal-3 associated with CD147 and integrin-β1, but not with integrin-α3. Additionally, association of Gal-3 with CD147 and integrin-β1 was observed in co-localization analyses, while integrin-α3 only partially co-localized with Gal-3. Blocking of CD147 and integrin-β1 on RPE cell surfaces inhibited binding of Gal-3, whereas blocking of integrin-α3 failed to do so, suggesting that integrin-α3 is rather an indirect interactor. Importantly, Gal-3 binding promoted pronounced clustering and co-localization of CD147 and integrin-β1, with only partial association of integrin-α3. Finally, we show that RPE derived CD147 and integrin-β1, but not integrin-α3, carry predominantly β-1,6-N-actyl-D-glucosamine-branched glycans, which are high-affinity ligands for Gal-3. We conclude from these data that extracellular Gal-3 triggers

  6. Galectin-3 Induces Clustering of CD147 and Integrin-β1 Transmembrane Glycoprotein Receptors on the RPE Cell Surface

    Science.gov (United States)

    Priglinger, Claudia S.; Szober, Christoph M.; Priglinger, Siegfried G.; Merl, Juliane; Euler, Kerstin N.; Kernt, Marcus; Gondi, Gabor; Behler, Jennifer; Geerlof, Arie; Kampik, Anselm; Ueffing, Marius; Hauck, Stefanie M.

    2013-01-01

    Proliferative vitreoretinopathy (PVR) is a blinding disease frequently occurring after retinal detachment surgery. Adhesion, migration and matrix remodeling of dedifferentiated retinal pigment epithelial (RPE) cells characterize the onset of the disease. Treatment options are still restrained and identification of factors responsible for the abnormal behavior of the RPE cells will facilitate the development of novel therapeutics. Galectin-3, a carbohydrate-binding protein, was previously found to inhibit attachment and spreading of retinal pigment epithelial cells, and thus bares the potential to counteract PVR-associated cellular events. However, the identities of the corresponding cell surface glycoprotein receptor proteins on RPE cells are not known. Here we characterize RPE-specific Gal-3 containing glycoprotein complexes using a proteomic approach. Integrin-β1, integrin-α3 and CD147/EMMPRIN, a transmembrane glycoprotein implicated in regulating matrix metalloproteinase induction, were identified as potential Gal-3 interactors on RPE cell surfaces. In reciprocal immunoprecipitation experiments we confirmed that Gal-3 associated with CD147 and integrin-β1, but not with integrin-α3. Additionally, association of Gal-3 with CD147 and integrin-β1 was observed in co-localization analyses, while integrin-α3 only partially co-localized with Gal-3. Blocking of CD147 and integrin-β1 on RPE cell surfaces inhibited binding of Gal-3, whereas blocking of integrin-α3 failed to do so, suggesting that integrin-α3 is rather an indirect interactor. Importantly, Gal-3 binding promoted pronounced clustering and co-localization of CD147 and integrin-β1, with only partial association of integrin-α3. Finally, we show that RPE derived CD147 and integrin-β1, but not integrin-α3, carry predominantly β-1,6-N-actyl-D-glucosamine-branched glycans, which are high-affinity ligands for Gal-3. We conclude from these data that extracellular Gal-3 triggers clustering of CD147 and

  7. Abnormalities of lymphocyte function and phenotypic pattern in a case of toxic epidermal necrolysis

    DEFF Research Database (Denmark)

    Hagdrup, H; Tønnesen, E; Clemmensen, O

    1992-01-01

    We examined the blood lymphocyte function and phenotypic pattern in a patient with toxic epidermal necrolysis after taking salazopyrin. We studied cell surface markers, natural killer cell activity and mitogen-induced lymphocyte transformation. Our results point to temporary immunosuppression...... as evidenced by lymphopenia with a large "null cell" population, reduced natural killer cell activity, and impaired lymphocyte response to mitogens....

  8. Fish Lymphocytes: An Evolutionary Equivalent of Mammalian Innate-Like Lymphocytes?

    Directory of Open Access Journals (Sweden)

    Giuseppe Scapigliati

    2018-05-01

    Full Text Available Lymphocytes are the responsible of adaptive responses, as they are classically described, but evidence shows that subpopulations of mammalian lymphocytes may behave as innate-like cells, engaging non-self rapidly and without antigen presentation. The innate-like lymphocytes of mammals have been mainly identified as γδT cells and B1-B cells, exert their activities principally in mucosal tissues, may be involved in human pathologies and their functions and tissue(s of origin are not fully understood. Due to similarities in the morphology and immunobiology of immune system between fish and mammals, and to the uniqueness of having free-living larval stages where the development can be precisely monitored and engineered, teleost fish are proposed as an experimental model to investigate human immunity. However, the homology between fish lymphocytes and mammalian innate-like lymphocytes is an issue poorly considered in comparative immunology. Increasing experimental evidence suggests that fish lymphocytes could have developmental, morphological, and functional features in common with innate-like lymphocytes of mammals. Despite such similarities, information on possible links between conventional fish lymphocytes and mammalian innate-like lymphocytes is missing. The aim of this review is to summarize and describe available findings about the similarities between fish lymphocytes and mammalian innate-like lymphocytes, supporting the hypothesis that mammalian γδT cells and B1-B cells could be evolutionarily related to fish lymphocytes.

  9. Ibrutinib Inhibits Platelet Integrin αIIbβ3 Outside-In Signaling and Thrombus Stability But Not Adhesion to Collagen.

    Science.gov (United States)

    Bye, Alexander P; Unsworth, Amanda J; Vaiyapuri, Sakthivel; Stainer, Alexander R; Fry, Michael J; Gibbins, Jonathan M

    2015-11-01

    Ibrutinib is an irreversible Bruton tyrosine kinase inhibitor approved for treatment of Waldenstrom macroglobulinemia, chronic lymphocytic leukemia, and mantle cell lymphoma that increases the risk of bleeding among patients. Platelets from ibrutinib-treated patients exhibit deficiencies in collagen-evoked signaling in suspension; however, the significance of this observation and how it relates to bleeding risk is unclear, as platelets encounter immobile collagen in vivo. We sought to clarify the effects of ibrutinib on platelet function to better understand the mechanism underlying bleeding risk. By comparing signaling in suspension and during adhesion to immobilized ligands, we found that the collagen signaling deficiency caused by ibrutinib is milder during adhesion to immobilized collagen. We also found that platelets in whole blood treated with ibrutinib adhered to collagen under arterial shear but formed unstable thrombi, suggesting that the collagen signaling deficiency caused by ibrutinib may not be the predominant cause of bleeding in vivo. However, clot retraction and signaling evoked by platelet adhesion to immobilized fibrinogen were also inhibited by ibrutinib, indicating that integrin αIIbβ3 outside-in signaling is also effected in addition to GPVI signaling. When ibrutinib was combined with the P2Y12 inhibitor, cangrelor, thrombus formation under arterial shear was inhibited additively. These findings suggest that (1) ibrutinib causes GPVI and integrin αIIbβ3 platelet signaling deficiencies that result in formation of unstable thrombi and may contribute toward bleeding observed in vivo and (2) combining ibrutinib with P2Y12 antagonists, which also inhibit thrombus stability, may have a detrimental effect on hemostasis. © 2015 American Heart Association, Inc.

  10. Integrin α5β1, the Fibronectin Receptor, as a Pertinent Therapeutic Target in Solid Tumors

    Energy Technology Data Exchange (ETDEWEB)

    Schaffner, Florence; Ray, Anne Marie; Dontenwill, Monique, E-mail: monique.dontenwill@unistra.fr [UMR 7213 CNRS, Laboratoire de Biophotonique et Pharmacologie, Tumoral signaling and therapeutic targets, Université de Strasbourg, Faculté de Pharmacie, 67401 Illkirch (France)

    2013-01-15

    Integrins are transmembrane heterodimeric proteins sensing the cell microenvironment and modulating numerous signalling pathways. Changes in integrin expression between normal and tumoral cells support involvement of specific integrins in tumor progression and aggressiveness. This review highlights the current knowledge about α5β1 integrin, also called the fibronectin receptor, in solid tumors. We summarize data showing that α5β1 integrin is a pertinent therapeutic target expressed by tumoral neovessels and tumoral cells. Although mainly evaluated in preclinical models, α5β1 integrin merits interest in particular in colon, breast, ovarian, lung and brain tumors where its overexpression is associated with a poor prognosis for patients. Specific α5β1 integrin antagonists will be listed that may represent new potential therapeutic agents to fight defined subpopulations of particularly aggressive tumors.

  11. Kindlins, integrin activation and the regulation of talin recruitment to αIIbβ3.

    Directory of Open Access Journals (Sweden)

    Bryan N Kahner

    Full Text Available Talins and kindlins bind to the integrin β3 cytoplasmic tail and both are required for effective activation of integrin αIIbβ3 and resulting high-affinity ligand binding in platelets. However, binding of the talin head domain alone to β3 is sufficient to activate purified integrin αIIbβ3 in vitro. Since talin is localized to the cytoplasm of unstimulated platelets, its re-localization to the plasma membrane and to the integrin is required for activation. Here we explored the mechanism whereby kindlins function as integrin co-activators. To test whether kindlins regulate talin recruitment to plasma membranes and to αIIbβ3, full-length talin and kindlin recruitment to β3 was studied using a reconstructed CHO cell model system that recapitulates agonist-induced αIIbβ3 activation. Over-expression of kindlin-2, the endogenous kindlin isoform in CHO cells, promoted PAR1-mediated and talin-dependent ligand binding. In contrast, shRNA knockdown of kindlin-2 inhibited ligand binding. However, depletion of kindlin-2 by shRNA did not affect talin recruitment to the plasma membrane, as assessed by sub-cellular fractionation, and neither over-expression of kindlins nor depletion of kindlin-2 affected talin interaction with αIIbβ3 in living cells, as monitored by bimolecular fluorescence complementation. Furthermore, talin failed to promote kindlin-2 association with αIIbβ3 in CHO cells. In addition, purified talin and kindlin-3, the kindlin isoform expressed in platelets, failed to promote each other's binding to the β3 cytoplasmic tail in vitro. Thus, kindlins do not promote initial talin recruitment to αIIbβ3, suggesting that they co-activate integrin through a mechanism independent of recruitment.

  12. Associations between lifestyles and neutrophil-lymphocyte and platelet-lymphocyte ratios in colorectal cancer.

    Science.gov (United States)

    Hong, Chuyuan; Wei, Yisheng; Jiang, Jianxin; Zhao, Chuxiong; Liang, Guojian; Wang, Guoqiang; Yang, Hui

    2014-06-01

    To explore the etiology of the neutrophil-lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR) abnormalities in colorectal cancer. In total, 230 patients with histopathologically confirmed colorectal cancer from August 2009 to August 2011 were recruited to our study. The associations between lifestyles (smoking, alcohol and pickled food consumption) and pretreatment NLR and PLR were estimated using the Kruskal-Wallis tests and linear regression model. The Kruskal-Wallis test showed a significant association between pickled food intake and pretreatment NLR but not PLR (P = 0.002, 0.057, respectively). Pairwise comparisons showed that, compared with those with a moderately frequent (2-3 times/week) and an infrequent (≤ once a week) intake of pickled food, high frequency (≥ four times/week) consumption of pickled food had a higher pretreatment NLR (P = 0.01, 0.007, respectively). Multivariate linear regression analysis showed pretreatment NLR increased significantly in high frequency (≥ four times/week) consumption of pickled food (P frequency intake of pickled food possibly contributes to higher NLR, which may reflect a systemic inflammatory response in colorectal cancer. © 2013 Wiley Publishing Asia Pty Ltd.

  13. An improved method on stimulated T-lymphocytes to functionally characterize novel and known LDLR mutations[S

    Science.gov (United States)

    Romano, Maria; Di Taranto, Maria Donata; Mirabelli, Peppino; D'Agostino, Maria Nicoletta; Iannuzzi, Arcangelo; Marotta, Gennaro; Gentile, Marco; Raia, Maddalena; Di Noto, Rosa; Del Vecchio, Luigi; Rubba, Paolo; Fortunato, Giuliana

    2011-01-01

    The main causes of familial hypercholesterolemia (FH) are mutations in LDL receptor (LDLR) gene. Functional studies are necessary to demonstrate the LDLR function impairment caused by mutations and would be useful as a diagnostic tool if they allow discrimination between FH patients and controls. In order to identify the best method to detect LDLR activity, we compared continuous Epstein-Barr virus (EBV)-transformed B-lymphocytes and mitogen stimulated T-lymphocytes. In addition, we characterized both novel and known mutations in the LDLR gene. T-lymphocytes and EBV-transformed B-lymphocytes were obtained from peripheral blood of 24 FH patients and 24 control subjects. Functional assays were performed by incubation with fluorescent LDL followed by flow cytometry analysis. Residual LDLR activity was calculated normalizing fluorescence for the mean fluorescence of controls. With stimulated T-lymphocytes we obtained a better discrimination capacity between controls and FH patients compared with EBV-transformed B-lymphocytes as demonstrated by receiver operating characteristic (ROC) curve analysis (the areas under the curve are 1.000 and 0.984 respectively; P < 0.0001 both). The characterization of LDLR activity through T-lymphocytes is more simple and faster than the use of EBV-transformed B-lymphocytes and allows a complete discrimination between controls and FH patients. Therefore the evaluation of residual LDLR activity could be helpful not only for mutation characterization but also for diagnostic purposes. PMID:21865347

  14. Genome-wide association study identifies multiple risk loci for chronic lymphocytic leukemia

    OpenAIRE

    Berndt, S.I.; Skibola, C.F.; Joseph, V.; Camp, N.J.; Nieters, A.; Wang, Z.; Cozen, W.; Monnereau, A.; Wang, S.S.; Kelly, R.S.; Lan, Q.; Teras, L.R.; Chatterjee, N.; Chung, C.C.; Yeager, M.

    2013-01-01

    Genome-wide association studies (GWAS) have previously identified 13 loci associated with risk of chronic lymphocytic leukemia or small lymphocytic lymphoma (CLL). To identify additional CLL susceptibility loci, we conducted the largest meta-analysis for CLL thus far, including four GWAS with a total of 3,100 individuals with CLL (cases) and 7,667 controls. In the meta-analysis, we identified ten independent associated SNPs in nine new loci at 10q23.31 (ACTA2 or FAS (ACTA2/FAS), P = 1.22 × 10...

  15. Stress, cortisol, and B lymphocytes: a novel approach to understanding academic stress and immune function.

    Science.gov (United States)

    McGregor, Bonnie A; Murphy, Karly M; Albano, Denise L; Ceballos, Rachel M

    2016-01-01

    Animal and human in vitro models suggest that stress-related B lymphocyte decrements are due to high levels of glucocorticoids which cause apoptosis of pre-B-cells as they emerge from the bone marrow. The present study sought to explore the relationships among distress, salivary cortisol, and human B lymphocytes in vivo. Distress (perceived stress, negative affect, depressive symptoms), lymphocyte phenotype, and salivary cortisol were assessed among first-year graduate students (n = 22) and a community control sample (n = 30) at the start of classes in the fall and the week immediately before spring preliminary exams. Compared to controls, students reported greater distress on all measures at each time point except baseline perceived stress. Hierarchical linear regression with necessary control variables was used to assess the effect of student status on the three measures of distress, the four measures of lymphocyte phenotype, and cortisol AUC and CAR over time (T1-T2). Student status was associated with a significant decrease in CD19 + B lymphocytes and flattened cortisol awakening response (CAR). Change in CAR was associated with the decrease in CD19 + B lymphocytes. Results indicated that there are significant associations among student status, flattening of CAR, and decrements in CD19 + lymphocytes.

  16. LFA-1 and Mac-1 integrins bind to the serine/threonine-rich domain of thrombomodulin

    Energy Technology Data Exchange (ETDEWEB)

    Kawamoto, Eiji [Department of Molecular Pathobiology and Cell Adhesion Biology, Mie University Graduate School of Medicine, 2-174 Edobashi, Tsu, Mie 514-8507 (Japan); Emergency and Critical Care Center, Mie University Hospital, 2-174 Edobashi, Tsu 514-8507 (Japan); Okamoto, Takayuki, E-mail: okamotot@doc.medic.mie-u.ac.jp [Department of Molecular Pathobiology and Cell Adhesion Biology, Mie University Graduate School of Medicine, 2-174 Edobashi, Tsu, Mie 514-8507 (Japan); Takagi, Yoshimi [Department of Molecular Pathobiology and Cell Adhesion Biology, Mie University Graduate School of Medicine, 2-174 Edobashi, Tsu, Mie 514-8507 (Japan); Honda, Goichi [Medical Affairs Department, Asahi Kasei Pharma Corporation, 1-105 Kanda Jinbo-cho, Chiyoda-ku, Tokyo 101-8101 (Japan); Suzuki, Koji [Faculty of Pharmaceutical Science, Suzuka University of Medical Science, 3500-3, Minamitamagaki-cho, Suzuka, Mie 513-8679 (Japan); Imai, Hiroshi [Emergency and Critical Care Center, Mie University Hospital, 2-174 Edobashi, Tsu 514-8507 (Japan); Shimaoka, Motomu, E-mail: shimaoka@doc.medic.mie-u.ac.jp [Department of Molecular Pathobiology and Cell Adhesion Biology, Mie University Graduate School of Medicine, 2-174 Edobashi, Tsu, Mie 514-8507 (Japan)

    2016-05-13

    LFA-1 (αLβ2) and Mac-1 (αMβ2) integrins regulate leukocyte trafficking in health and disease by binding primarily to IgSF ligand ICAM-1 and ICAM-2 on endothelial cells. Here we have shown that the anti-coagulant molecule thrombomodulin (TM), found on the surface of endothelial cells, functions as a potentially new ligand for leukocyte integrins. We generated a recombinant extracellular domain of human TM and Fc fusion protein (TM-domains 123-Fc), and showed that pheripheral blood mononuclear cells (PBMCs) bind to TM-domains 123-Fc dependent upon integrin activation. We then demonstrated that αL integrin-blocking mAb, αM integrin-blocking mAb, and β2 integrin-blocking mAb inhibited the binding of PBMCs to TM-domains 123-Fc. Furthermore, we show that the serine/threonine-rich domain (domain 3) of TM is required for the interaction with the LFA-1 (αLβ2) and Mac-1 (αMβ2) integrins to occur on PBMCs. These results demonstrate that the LFA-1 and Mac-1 integrins on leukocytes bind to TM, thereby establishing the molecular and structural basis underlying LFA-1 and Mac-1 integrin interaction with TM on endothelial cells. In fact, integrin-TM interactions might be involved in the dynamic regulation of leukocyte adhesion with endothelial cells. - Highlights: • LFA-1 and Mac-1 integrins bind to the anti-coagulant molecule thrombomodulin. • The serine/threonine-rich domain of thrombomodulin is essential to interact with the LFA-1 and Mac-1 integrins on PBMCs. • Integrin-TM interactions might be involved in the dynamic regulation of leukocyte adhesion with endothelial cells.

  17. Lipid raft regulates the initial spreading of melanoma A375 cells by modulating β1 integrin clustering.

    Science.gov (United States)

    Wang, Ruifei; Bi, Jiajia; Ampah, Khamal Kwesi; Zhang, Chunmei; Li, Ziyi; Jiao, Yang; Wang, Xiaoru; Ba, Xueqing; Zeng, Xianlu

    2013-08-01

    Cell adhesion and spreading require integrins-mediated cell-extracellular matrix interaction. Integrins function through binding to extracellular matrix and subsequent clustering to initiate focal adhesion formation and actin cytoskeleton rearrangement. Lipid raft, a liquid ordered plasma membrane microdomain, has been reported to play major roles in membrane motility by regulating cell surface receptor function. Here, we identified that lipid raft integrity was required for β1 integrin-mediated initial spreading of melanoma A375 cells on fibronectin. We found that lipid raft disruption with methyl-β-cyclodextrin led to the inability of focal adhesion formation and actin cytoskeleton rearrangement by preventing β1 integrin clustering. Furthermore, we explored the possible mechanism by which lipid raft regulates β1 integrin clustering and demonstrated that intact lipid raft could recruit and modify some adaptor proteins, such as talin, α-actinin, vinculin, paxillin and FAK. Lipid raft could regulate the location of these proteins in lipid raft fractions and facilitate their binding to β1 integrin, which may be crucial for β1 integrin clustering. We also showed that lipid raft disruption impaired A375 cell migration in both transwell and wound healing models. Together, these findings provide a new insight for the relationship between lipid raft and the regulation of integrins. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. The role of integrin αv in proliferation and differentiation of human dental pulp cell response to calcium silicate cement.

    Science.gov (United States)

    Hung, Chi-Jr; Hsu, Hsin-I; Lin, Chi-Chang; Huang, Tsui-Hsien; Wu, Buor-Chang; Kao, Chia-Tze; Shie, Ming-You

    2014-11-01

    It has been proved that integrin αv activity is related to cell proliferation, differentiation, migration, and organ development. However, the biological functions of integrin αv in human dental pulp cells (hDPCs) cultured on silicate-based materials have not been explored. The aim of this study was to investigate the role of integrin αv in the proliferation and odontogenic differentiation of hDPCs cultured with the effect of calcium silicate (CS) cement and β-tricalcium phosphate (TCP) cement. In this study, hDPCs were cultured on CS and TCP materials, and we evaluated fibronectin (FN) secretion and integrin αv expression during the cell attachment stage. After small interfering RNA transfection targeting integrin αv, the proliferation and odontogenesis differentiation behavior of hDPCs were analyzed. The results indicate that CS releases Si ion-increased FN secretion and adsorption, which promote cell attachment more effectively than TCP. The CS cement facilitates FN and αv subintegrin expression. However, the FN adsorption and integrin expression of TCP are similar to that observed in the control dish. Integrin αv small interfering RNA inhibited odontogenic differentiation of hDPCs with the decreased formation of mineralized nodules on CS. It also down-regulated the protein expression of multiple markers of odontogenesis and the expression of dentin sialophosphoprotein protein. These results establish composition-dependent differences in integrin binding and its effectiveness as a mechanism regulating cellular responses to biomaterial surface. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  19. Modulation of type II TGF-β receptor degradation by integrin-linked kinase.

    Science.gov (United States)

    Vi, Linda; Boo, Stellar; Sayedyahossein, Samar; Singh, Randeep K; McLean, Sarah; Di Guglielmo, Gianni M; Dagnino, Lina

    2015-03-01

    Cutaneous responses to injury, infection, and tumor formation involve the activation of resident dermal fibroblasts and subsequent transition to myofibroblasts. The key for induction of myofibroblast differentiation is the activation of transforming growth factor-β (TGF-β) receptors and stimulation of integrins and their associated proteins, including integrin-linked kinase (ILK). Cross-talk processes between TGF-β and ILK are crucial for myofibroblast formation, as ILK-deficient dermal fibroblasts exhibit impaired responses to TGF-β receptor stimulation. We now show that ILK associates with type II TGF-β receptors (TβRII) in ligand- and receptor kinase activity-independent manners. In cells with targeted Ilk gene inactivation, cellular levels of TβRII are decreased, through mechanisms that involve enhanced ubiquitination and proteasomal degradation. Partitioning of TGF-β receptors into membrane has been linked to proteasome-dependent receptor degradation. We found that interfering with membrane raft formation in ILK-deficient cells restored TβRII levels and signaling. These observations support a model whereby ILK functions in fibroblasts to direct TβRII away from degradative pathways during their differentiation into myofibroblasts.

  20. Dominant Suppression of β1 Integrin by Ectopic CD98-ICD Inhibits Hepatocellular Carcinoma Progression

    Directory of Open Access Journals (Sweden)

    Bo Wu

    2016-11-01

    Full Text Available Hepatocellular carcinoma (HCC is currently the third most common cause of cancer-related death in the Asia-Pacific region. Our previous work showed that knockdown of CD98 significantly inhibits malignant HCC cell phenotypes in vitro and in vivo. The level of CD98 in the membrane is tightly regulated to mediate complex processes associated with cell–cell communication and intracellular signaling. In addition, the intracellular domain of CD98 (CD98-ICD seems to be of vital importance for recycling CD98 to the membrane after it is endocytosed. The intracellular and transmembrane domains of CD98 associate with β-integrins (primarily β1 but also β3, and this association is essential for CD98 mediation of integrin-like signaling and complements dominant suppression of β1-integrin. We speculated that isolated CD98-ICD would similarly suppress β1-integrin activation and inhibit the malignant behaviors of cancer cells. In particular, the exact role of CD98-ICD has not been studied independently in HCC. In this study, we found that ectopic expression of CD98-ICD inhibited the malignant phenotypes of HCC cells, and the mechanism possibly involves β1-integrin suppression. Moreover, the expression levels of CD98, β1-integrin-A (the activated form of β1-integrin and Ki-67 were significantly increased in HCC tissues relative to those of normal liver tissues. Therefore, our preliminary study indicates that ectopic CD98-ICD has an inhibitory role in the malignant development of HCC, and shows that CD98-ICD acts as a dominant negative mutant of CD98 that attenuates β1-integrin activation. CD98-ICD may emerge as a promising candidate for antitumor treatment.

  1. The involvement of Gab1 and PI 3-kinase in β1 integrin signaling in keratinocytes

    International Nuclear Information System (INIS)

    Kuwano, Yoshihiro; Fujimoto, Manabu; Watanabe, Rei; Ishiura, Nobuko; Nakashima, Hiroko; Komine, Mayumi; Hamazaki, Tatsuo S.; Tamaki, Kunihiko; Okochi, Hitoshi

    2007-01-01

    The control of the stem cell compartment in epidermis is closely linked to the regulation of keratinocyte proliferation and differentiation. β1 integrins are expressed 2-fold higher by stem cells than transit-amplifying cells. Signaling from these β1 integrins is critical for the regulation of the epidermal stem cell compartment. To clarify the functional relevance of this differential expression of β1 integrins, we established HaCaT cells with high β1integrin expression by repeated flow cytometric sorting of this population from the parental cell line. In these obtained cells expressing β1 integrins by 5-fold, MAPK activation was markedly increased. Regarding the upstream of MAPK, Gab1 phosphorylation was also higher with high β1 integrin expression, while Shc phosphorylation was not altered. In addition, enhanced phosphatidylinositol 3-kinase activation was also observed. These observations suggest that Gab1 and phosphatidylinositol 3-kinase play pivotal roles in the β1 integrin-mediated regulation of the epidermal stem cell compartment

  2. Lymphocyte function following radium-223 therapy in patients with metastasized, castration-resistant prostate cancer

    International Nuclear Information System (INIS)

    Barsegian, Vahe; Moeckel, Daniel; Mueller, Stefan P.; Bockisch, Andreas; Horn, Peter A.; Lindemann, Monika

    2017-01-01

    Therapy with the alpha-emitter radium-223 chloride ("2"2"3Ra) is an innovative therapeutic option in patients with metastasized, castration-resistant prostate cancer. However, radiotherapy can lead to hematopoietic toxicity. The aim of this study was to determine if "2"2"3Ra therapy induces an impairment of cellular antimicrobial immune responses. In 11 patients receiving "2"2"3Ra treatment, lymphocyte proliferation and the production of pro- and anti-inflammatory cytokines (interferon-γ and interleukin-10) were determined, using lymphocyte transformation testing and ELISpot, respectively. Lymphocyte function after stimulation with mitogens and microbial antigens was assessed prior to therapy and at day 1, 7 and 28 after therapy. Lymphocyte proliferation and the production of interferon-γ and interleukin-10 towards mitogens and antigens remained unchanged after therapy. Consistent with these in vitro data, we did not observe infectious complications after treatment. The results argue against an impairment of lymphocyte function after "2"2"3Ra therapy. Thus, immune responses against pathogens should remain unaffected. (orig.)

  3. Expression and putative function of fibronectin and its receptor (integrin alpha(5)beta(1)) in male and female gametes during bovine fertilization in vitro.

    Science.gov (United States)

    Thys, Mirjan; Nauwynck, Hans; Maes, Dominiek; Hoogewijs, Maarten; Vercauteren, Dries; Rijsselaere, Tom; Favoreel, Herman; Van Soom, Ann

    2009-09-01

    Fibronectin (Fn) is a 440 kDa glycoprotein assumed to participate in sperm-egg interaction in human. Recently, it has been demonstrated that Fn--when present during bovine IVF--strongly inhibits sperm penetration. The present study was conducted firstly to evaluate the expression of Fn and its integrin receptor (alpha(5)beta(1)) on male and female bovine gametes using indirect immunofluorescence and secondly, to determine the function of Fn during bovine IVF. Endogenous Fn was detected underneath the zona pellucida (ZP) and integrin alpha(5) on the oolemma of cumulus-denuded oocytes. Bovine spermatozoa displayed integrin alpha(5) at their equatorial segment after acrosome reaction. We established that the main inhibitory effect of exogenously supplemented Fn was located at the sperm-oolemma binding, with a (concurrent) effect on fusion, and this can probably be attributed to the binding of Fn to spermatozoa at the equatorial segment, as shown by means of Alexa Fluor 488-conjugated Fn. Combining these results, the inhibitory effect of exogenously supplemented Fn seemed to be exerted on the male gamete by binding to the exposed integrin alpha(5)beta(1) receptor after acrosome reaction. The presence of endogenous Fn underneath the ZP together with integrin alpha(5) expression on oolemma and acrosome-reacted (AR) sperm cell surface suggests a 'velcro' interaction between the endogenous Fn ligand and corresponding receptors on both (AR) sperm cell and oolemma, initiating sperm-egg binding.

  4. Dual mechanism of integrin αIIbβ3 closure in procoagulant platelets.

    Science.gov (United States)

    Mattheij, Nadine J A; Gilio, Karen; van Kruchten, Roger; Jobe, Shawn M; Wieschhaus, Adam J; Chishti, Athar H; Collins, Peter; Heemskerk, Johan W M; Cosemans, Judith M E M

    2013-05-10

    Inactivation of integrin αIIbβ3 reverses platelet aggregate formation upon coagulation. Platelets from patient (Scott) and mouse (Capn1(-/-) and Ppif(-/-)) blood reveal a dual mechanism of αIIbβ3 inactivation: by calpain-2 cleavage of integrin-associated proteins and by cyclophilin D/TMEM16F-dependent phospholipid scrambling. These data provide novel insight into the switch mechanisms from aggregating to procoagulant platelets. Aggregation of platelets via activated integrin αIIbβ3 is a prerequisite for thrombus formation. Phosphatidylserine-exposing platelets with a key role in the coagulation process disconnect from a thrombus by integrin inactivation via an unknown mechanism. Here we show that αIIbβ3 inactivation in procoagulant platelets relies on a sustained high intracellular Ca(2+), stimulating intracellular cleavage of the β3 chain, talin, and Src kinase. Inhibition of calpain activity abolished protein cleavage, but only partly suppressed αIIbβ3 inactivation. Integrin αIIbβ3 inactivation was unchanged in platelets from Capn1(-/-) mice, suggesting a role of the calpain-2 isoform. Scott syndrome platelets, lacking the transmembrane protein TMEM16F and having low phosphatidylserine exposure, displayed reduced αIIbβ3 inactivation with the remaining activity fully dependent on calpain. In platelets from Ppif(-/-) mice, lacking mitochondrial permeability transition pore (mPTP) formation, agonist-induced phosphatidylserine exposure and αIIbβ3 inactivation were reduced. Treatment of human platelets with cyclosporin A gave a similar phenotype. Together, these data point to a dual mechanism of αIIbβ3 inactivation via calpain(-2) cleavage of integrin-associated proteins and via TMEM16F-dependent phospholipid scrambling with an assistant role of mPTP formation.

  5. Pathological lymphangiogenesis is modulated by galectin-8-dependent crosstalk between podoplanin and integrin-associated VEGFR-3.

    Science.gov (United States)

    Chen, Wei-Sheng; Cao, Zhiyi; Sugaya, Satoshi; Lopez, Maria J; Sendra, Victor G; Laver, Nora; Leffler, Hakon; Nilsson, Ulf J; Fu, Jianxin; Song, Jianhua; Xia, Lijun; Hamrah, Pedram; Panjwani, Noorjahan

    2016-04-12

    Lymphangiogenesis plays a pivotal role in diverse pathological conditions. Here, we demonstrate that a carbohydrate-binding protein, galectin-8, promotes pathological lymphangiogenesis. Galectin-8 is markedly upregulated in inflamed human and mouse corneas, and galectin-8 inhibitors reduce inflammatory lymphangiogenesis. In the mouse model of corneal allogeneic transplantation, galectin-8-induced lymphangiogenesis is associated with an increased rate of corneal graft rejection. Further, in the murine model of herpes simplex virus keratitis, corneal pathology and lymphangiogenesis are ameliorated in Lgals8(-/-) mice. Mechanistically, VEGF-C-induced lymphangiogenesis is significantly reduced in the Lgals8(-/-) and Pdpn(-/-) mice; likewise, galectin-8-induced lymphangiogenesis is reduced in Pdpn(-/-) mice. Interestingly, knockdown of VEGFR-3 does not affect galectin-8-mediated lymphatic endothelial cell (LEC) sprouting. Instead, inhibiting integrins α1β1 and α5β1 curtails both galectin-8- and VEGF-C-mediated LEC sprouting. Together, this study uncovers a unique molecular mechanism of lymphangiogenesis in which galectin-8-dependent crosstalk among VEGF-C, podoplanin and integrin pathways plays a key role.

  6. Association of High Density Lipoprotein with Platelet to Lymphocyte and Neutrophil to Lymphocyte Ratios in Coronary Artery Disease Patients

    Directory of Open Access Journals (Sweden)

    Jayesh H. Prajapati

    2014-01-01

    Full Text Available Background. We aimed to evaluate a relationship between platelet-lymphocyte ratio (PLR and neutrophil-lymphocyte ratio (NLR with high density lipoprotein (HDL cholesterol levels in coronary artery disease (CAD patients. Methods. A total of 354 patients with angiographically confirmed coronary blockages were enrolled in the study. Hematological indices and lipid profiling data of all the patients were collected. Results. We have observed significant association between HDL and PLR (P=0.008 and NLR (P=0.009; however no significant relationship was obtained with HDL and isolated platelet (P=0.488, neutrophil (P=0.407, and lymphocyte (P=0.952 counts in CAD patients. The association was subjected to gender specific variation as in males PLR (P=0.024 and NLR (P=0.03 were highly elevated in low HDL patients, whereas in females the elevation could not reach the statistically significant level. The PLR (217.47 versus 190.3; P=0.01 and NLR (6.33 versus 5.10; P=0.01 were significantly higher among the patients with acute coronary syndrome. In young patients the PLR (P=0.007 and NLR (P=0.001 were inversely associated with HDL, whereas in older population only NLR (P=0.05 had showed a significant association. Conclusion. We conclude that PLR and NLR are significantly elevated in CAD patients having low HDL levels.

  7. CCM proteins control endothelial β1 integrin dependent response to shear stress

    Directory of Open Access Journals (Sweden)

    Zuzana Macek Jilkova

    2014-11-01

    Full Text Available Hemodynamic shear stress from blood flow on the endothelium critically regulates vascular function in many physiological and pathological situations. Endothelial cells adapt to shear stress by remodeling their cytoskeletal components and subsequently by changing their shape and orientation. We demonstrate that β1 integrin activation is critically controlled during the mechanoresponse of endothelial cells to shear stress. Indeed, we show that overexpression of the CCM complex, an inhibitor of β1 integrin activation, blocks endothelial actin rearrangement and cell reorientation in response to shear stress similarly to β1 integrin silencing. Conversely, depletion of CCM2 protein leads to an elongated “shear-stress-like” phenotype even in the absence of flow. Taken together, our findings reveal the existence of a balance between positive extracellular and negative intracellular signals, i.e. shear stress and CCM complex, for the control of β1 integrin activation and subsequent adaptation of vascular endothelial cells to mechanostimulation by fluid shear stress.

  8. Endothelial-monocyte activating polypeptide II alters fibronectin based endothelial cell adhesion and matrix assembly via alpha5 beta1 integrin

    International Nuclear Information System (INIS)

    Schwarz, Margaret A.; Zheng, Hiahua; Liu, Jie; Corbett, Siobhan; Schwarz, Roderich E.

    2005-01-01

    Mature Endothelial-Monocyte Activating Polypeptide (mEMAP) II functions as a potent antiangiogenic peptide. Although the anti-tumor effect of mEMAP II has been described, little is known regarding its mechanism of action. Observations that mEMAP II induced apoptosis only in a subset of migrating and proliferating endothelial cells (EC) suggests a targeted effect on cells engaged in angiogenic activities which are known to rely upon cell adhesion and migration. Indeed, we demonstrate that mEMAP II inhibited fibronectin (FN) dependent microvascular EC (MEC) adhesion and spreading and we show that this depends upon the alpha5 beta1 integrin. Immunofluorescence analysis demonstrated that mEMAP II-dependent blockade of FN-alpha5 beta1 interactions was associated with disassembly of both actin stress fiber networks and FN matrix. These findings suggest that mEMAP II blocks MEC adhesion and spreading on fibronectin, via a direct interaction with the integrin alpha5 beta1, thus implicating that alpha5 integrin may be a mediator of mEMAP II's antiangiogenic function

  9. Long-lived, high-strength states of ICAM-1 bonds to beta2 integrin, I

    DEFF Research Database (Denmark)

    Evans, Evan; Kinoshita, Koji; Simon, Scott

    2010-01-01

    Using single-molecule force spectroscopy to probe ICAM-1 interactions with recombinant alphaLbeta2 immobilized on microspheres and beta2 integrin on neutrophils, we quantified an impressive hierarchy of long-lived, high-strength states of the integrin bond, which start from basal levels with inte......Using single-molecule force spectroscopy to probe ICAM-1 interactions with recombinant alphaLbeta2 immobilized on microspheres and beta2 integrin on neutrophils, we quantified an impressive hierarchy of long-lived, high-strength states of the integrin bond, which start from basal levels...... with integrin activation in solutions of divalent cations and shift dramatically upward to hyperactivated states with cell signaling in leukocytes. Taking advantage of very rare events, we used repeated measurements of bond lifetimes under steady ramps of force to achieve a direct assay for the off......-based assays of soluble ICAM-1 dissociation from immobilized LFA-1, i.e., approximately 10(-2)/s in Mg2+ or Mn2+ and approximately 1/s in Ca2+. At the same time, as expected for adhesive function, we find that the beta2 integrin bonds activated in Mn2+ or Mg2+ possess significant and persistent mechanical...

  10. Function of Etk in Growth Factor Receptor Signaling to Integrins in Breast Cancer

    National Research Council Canada - National Science Library

    Shimizu, Yoji

    2001-01-01

    The central hypothesis in this IDEA Award is that increased integrin-mediated adhesiveness and migration of breast cancer cells in response to stimulation by the growth factors heregulin beta (HRG beta...

  11. I-domain of lymphocyte function-associated antigen-1 mediates rolling of polystyrene particles on ICAM-1 under flow.

    Science.gov (United States)

    Eniola, A Omolola; Krasik, Ellen F; Smith, Lee A; Song, Gang; Hammer, Daniel A

    2005-11-01

    In their active state, beta(2)-integrins, such as LFA-1, mediate the firm arrest of leukocytes by binding intercellular adhesion molecules (ICAMs) expressed on endothelium. Although the primary function of LFA-1 is assumed to be the ability to mediate firm adhesion, recent work has shown that LFA-1 can contribute to cell tethering and rolling under hydrodynamic flow, a role previously largely attributed to the selectins. The inserted (I) domain of LFA-1 has recently been crystallized in the wild-type (wt) and locked-open conformations and has been shown to, respectively, support rolling and firm adhesion under flow when expressed in alpha(L)beta(2) heterodimers or as isolated domains on cells. Here, we report results from cell-free adhesion assays where wt I-domain-coated polystyrene particles were allowed to interact with ICAM-1-coated surfaces in shear flow. We show that wt I-domain can independently mediate the capture of particles from flow and support their rolling on ICAM-1 surfaces in a manner similar to how carbohydrate-selectin interactions mediate rolling. Adhesion is specific and blocked by appropriate antibodies. We also show that the rolling velocity of I-domain-coated particles depends on the wall shear stress in flow chamber, I-domain site density on microsphere surfaces, and ICAM-1 site density on substrate surfaces. Furthermore, we show that rolling is less sensitive to wall shear stress and ICAM-1 substrate density at high density of I-domain on the microsphere surface. Computer simulations using adhesive dynamics can recreate bead rolling dynamics and show that the mechanochemical properties of ICAM-1-I-domain interactions are similar to those of carbohydrate-selectin interactions. Understanding the biophysics of adhesion mediated by the I-domain of LFA-1 can elucidate the complex roles this integrin plays in leukocyte adhesion in inflammation.

  12. Immunomodulatory effects of Bacteroides products on in vitro human lymphocyte functions.

    Science.gov (United States)

    Shenker, B J; Slots, J

    1989-03-01

    Bacteroides spp. have been implicated in the pathogenesis of several diseases, including periodontal diseases. In this study sonic extracts of 6 Bacteroides spp. were examined for their abilities to alter human lymphocyte function. We found that soluble extracts from Bacteroides intermedius, Bacteroides endodontalis, Bacteroides asaccharolyticus, Bacteroides melaninogenicus, and to a lesser degree Bacteroides loescheii, caused dose-dependent inhibition of human lymphocyte responsiveness to both mitogens and antigens. Suppression involved altered DNA, RNA and protein synthesis as well as immunoglobulin production. In contrast, Bacteroides gingivalis did not suppress these responses; instead, it stimulated lymphocyte proliferation and enhanced immunoglobulin production. It has been proposed that impaired host defense may play a pivotal role in the pathogenesis of many infections. The data presented in this paper suggest that microbial mediated immunosuppression may conceivably alter the nature and consequences of host-parasite interactions in periodontal disease.

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

    NARCIS (Netherlands)

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

    2010-01-01

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

  14. Suppression of bovine lymphocyte function by treatment with physiologic concentrations of cortisone

    International Nuclear Information System (INIS)

    Ojo-Amaize, E.A.; Paape, M.J.; Guidry, A.J.; Mayer, H.K.

    1986-01-01

    The blastogenic response of peripheral blood lymphocytes (PBL) (8 cows) to capsular antigen extract of Staphylococcus aureus, PHA and LPS was measured in vitro using 5 H-thymidine pulse labelling. isolated PBL were treated in vitro for 6-8 days with 10, 25 and 45 ng/ml cortisone. These concentrations simulate serum corticosteroid levels during environmental stress, acute clinical mastitis and ACTH therapy, respectively. To determine the minimal concentration of cortisone that would induce suppression, PBL were also incubated with increasing concentrations of cortisone starting at 10 pg/ml. All concentrations of cortisone caused a significant (P<0.01) depression of lymphocyte blastogenic response to S. aureus, PHA and LPS. Macrophage depletion experiments showed no macrophage suppressor effects. Both the blastogenic response of untreated peripheral blood lymphocytes to S. aureus, PHA and LPS and the degree to which that response was suppressed by cortisone differed significantly among cows. Results indicate that cortisone levels found during physiological stress and after therapeutic administration of ACTH can suppress lymphocyte function

  15. Epithelial V-like antigen mediates efficacy of anti-alpha₄ integrin treatment in a mouse model of multiple sclerosis.

    Directory of Open Access Journals (Sweden)

    Erik Wright

    Full Text Available Natalizumab inhibits the transmigration of activated T lymphocytes into the brain and is highly efficacious in multiple sclerosis (MS. However, from a pharmacogenomic perspective, its efficacy and safety in specific patients remain unclear. Here our goal was to analyze the effects of epithelial V-like antigen (EVA on anti-alpha₄ integrin (VLA4 efficacy in a mouse model of MS, experimental autoimmune encephalomyelitis (EAE. EVA has been previously characterized in human CD4 T lymphocytes, mouse thymic development, and choroid plexus epithelial cells. Further analysis here demonstrated expression in B lymphocytes and an increase in EVA⁺ lymphocytes following immunization. Following active induction of EAE using the MOG³⁵⁻⁵⁵ active immunization model, EVA deficient mice developed more severe EAE and white matter tissue injury as compared to wild type controls. This severe EAE phenotype did not respond to anti-VLA4 treatment. In both the control antibody and anti-VLA4 conditions, these mice demonstrated persistent CNS invasion of mature B lymphocyte (CD19⁺, CD21⁺, sIgG⁺, increased serum autoantibody levels, and extensive complement and IgG deposition within lesions containing CD5⁺IgG⁺ cells. Wild type mice treated with control antibody also demonstrated the presence of CD19⁺, CD21⁺, sIgG⁺ cells within the CNS during peak EAE disease severity and detectable serum autoantibody. In contrast, wild type mice treated with anti-VLA4 demonstrated reduced serum autoantibody levels as compared to wild type controls and EVA-knockout mice. As expected, anti-VLA4 treatment in wild type mice reduced the total numbers of all CNS mononuclear cells and markedly decreased CD4 T lymphocyte invasion. Treatment also reduced the frequency of CD19⁺, CD21⁺, sIgG⁺ cells in the CNS. These results suggest that anti-VLA4 treatment may reduce B lymphocyte associated autoimmunity in some individuals and that EVA expression is necessary for an

  16. The changing integrin expression and a role for integrin β8 in the chondrogenic differentiation of mesenchymal stem cells.

    Directory of Open Access Journals (Sweden)

    Vanessa L S LaPointe

    Full Text Available Many cartilage tissue engineering approaches aim to differentiate human mesenchymal stem cells (hMSCs into chondrocytes and develop cartilage in vitro by targeting cell-matrix interactions. We sought to better inform the design of cartilage tissue engineering scaffolds by understanding how integrin expression changes during chondrogenic differentiation. In three models of in vitro chondrogenesis, we studied the temporal change of cartilage phenotype markers and integrin subunits during the differentiation of hMSCs. We found that transcript expression of most subunits was conserved across the chondrogenesis models, but was significantly affected by the time-course of differentiation. In particular, ITGB8 was up-regulated and its importance in chondrogenesis was further established by a knockdown of integrin β8, which resulted in a non-hyaline cartilage phenotype, with no COL2A1 expression detected. In conclusion, we performed a systematic study of the temporal changes of integrin expression during chondrogenic differentiation in multiple chondrogenesis models, and revealed a role for integrin β8 in chondrogenesis. This work enhances our understanding of the changing adhesion requirements of hMSCs during chondrogenic differentiation and underlines the importance of integrins in establishing a cartilage phenotype.

  17. The Changing Integrin Expression and a Role for Integrin β8 in the Chondrogenic Differentiation of Mesenchymal Stem Cells

    Science.gov (United States)

    LaPointe, Vanessa L. S.; Verpoorte, Amanda; Stevens, Molly M.

    2013-01-01

    Many cartilage tissue engineering approaches aim to differentiate human mesenchymal stem cells (hMSCs) into chondrocytes and develop cartilage in vitro by targeting cell-matrix interactions. We sought to better inform the design of cartilage tissue engineering scaffolds by understanding how integrin expression changes during chondrogenic differentiation. In three models of in vitro chondrogenesis, we studied the temporal change of cartilage phenotype markers and integrin subunits during the differentiation of hMSCs. We found that transcript expression of most subunits was conserved across the chondrogenesis models, but was significantly affected by the time-course of differentiation. In particular, ITGB8 was up-regulated and its importance in chondrogenesis was further established by a knockdown of integrin β8, which resulted in a non-hyaline cartilage phenotype, with no COL2A1 expression detected. In conclusion, we performed a systematic study of the temporal changes of integrin expression during chondrogenic differentiation in multiple chondrogenesis models, and revealed a role for integrin β8 in chondrogenesis. This work enhances our understanding of the changing adhesion requirements of hMSCs during chondrogenic differentiation and underlines the importance of integrins in establishing a cartilage phenotype. PMID:24312400

  18. Association between neutrophil/lymphocyte ratio and coronary collateral circulation

    Directory of Open Access Journals (Sweden)

    Mustafa Oylumlu

    2012-03-01

    Full Text Available Objectives: To investigate relation between neutrophil/lymphocyte ratio and coronary collateral flow.Material and methods: Eighty-two patients admittedDicle University Medical Faculty Hospital Cardiology Departmentwith diagnosis of coronary artery disease anddetected significant stenosis or occlusion at least one ofthe coronary arteries, were included to study. Age, sex,presence of diabetes mellitus and hypertension, acute/stable coronary disease, body mass index, neutrophil/lymphocyte ratio, white blood count, Rentrop scores andnumber of diseased vessel were recorded.Results: Well-developed coronary collateral circulationwas found in 33 of the patients. Forty-nine patients hadpoor coronary collateral circulation. Mean age, sex, bodymass index, presence of diabetes mellitus and hypertensionwere similar in two groups. Mean neutrophil/lymphocyteratio was lower in well-developed coronary collateralcirculation group than poor coronary collateral circulationgroup, but there was no significant differences (2.78 vs2.89, p=0.12.Conclusions: There was no association between neutron/hil lymphocyte ratio and coronary collateral circulationaccording to our data. J Clin Exp Invest 2012; 3(1:29-32

  19. Mena binds α5 integrin directly and modulates α5β1 function.

    Science.gov (United States)

    Gupton, Stephanie L; Riquelme, Daisy; Hughes-Alford, Shannon K; Tadros, Jenny; Rudina, Shireen S; Hynes, Richard O; Lauffenburger, Douglas; Gertler, Frank B

    2012-08-20

    Mena is an Ena/VASP family actin regulator with roles in cell migration, chemotaxis, cell-cell adhesion, tumor cell invasion, and metastasis. Although enriched in focal adhesions, Mena has no established function within these structures. We find that Mena forms an adhesion-regulated complex with α5β1 integrin, a fibronectin receptor involved in cell adhesion, motility, fibronectin fibrillogenesis, signaling, and growth factor receptor trafficking. Mena bound directly to the carboxy-terminal portion of the α5 cytoplasmic tail via a 91-residue region containing 13 five-residue "LERER" repeats. In fibroblasts, the Mena-α5 complex was required for "outside-in" α5β1 functions, including normal phosphorylation of FAK and paxillin and formation of fibrillar adhesions. It also supported fibrillogenesis and cell spreading and controlled cell migration speed. Thus, fibroblasts require Mena for multiple α5β1-dependent processes involving bidirectional interactions between the extracellular matrix and cytoplasmic focal adhesion proteins.

  20. Chondrocyte heterogeneity: immunohistologically defined variation of integrin expression at different sites in human fetal knees.

    Science.gov (United States)

    Salter, D M; Godolphin, J L; Gourlay, M S

    1995-04-01

    During development and at maturity different forms of cartilage vary in morphology and macromolecular content. This reflects heterogeneity of chondrocyte activity, in part involving differential interactions with the adjacent extracellular matrix via specialized cell surface receptors such as integrins. We undertook an immunohistological study on a series of human fetal knee joints to assess variation in the expression of integrins by chondrocytes and potential matrix ligands in articular, epiphyseal, growth plate, and meniscal cartilage. The results show that articular chondrocytes (beta 1+, beta 5 alpha V+, alpha 1+, alpha 2+/-, alpha 5+, weakly alpha 6+, alpha V+) differed from epiphyseal (beta 1+, beta 5 alpha V+, alpha 1+/-, alpha 2+/-, alpha 5+, alpha 6+, alpha V+) growth plate (beta 1+, beta 5 alpha V+, alpha 1-, alpha 2-, alpha 5+, alpha 6+, alpha V+), and meniscal cells (beta 1+, beta 5 alpha V+, alpha 1+, strongly alpha 2+, alpha 5+, alpha 6+, alpha V+ in expression of integrin subunits. There was no expression of beta 3, beta 4, beta 6, or alpha 3 by chondrocytes. These results differ from previous reports on the expression of integrins by adult articular cartilage, where alpha 2 and alpha 6 are not seen. Variation in distribution of matrix ligands was also seen. Fibronectin, laminin and Type VI collagen were expressed in all cartilages but there was restricted expression of tenascin, ED-A and ED-B fibronectin isoforms (articular cartilage and meniscus), and vitronectin (absent from growth plate cartilage). Regulated expression of integrins by chondrocytes, associated with changes in the pericellular matrix composition, is of potential importance in control of cartilage differentiation and function in health and disease.

  1. SHARPIN Regulates Uropod Detachment in Migrating Lymphocytes

    Directory of Open Access Journals (Sweden)

    Jeroen Pouwels

    2013-11-01

    Full Text Available SHARPIN-deficient mice display a multiorgan chronic inflammatory phenotype suggestive of altered leukocyte migration. We therefore studied the role of SHARPIN in lymphocyte adhesion, polarization, and migration. We found that SHARPIN localizes to the trailing edges (uropods of both mouse and human chemokine-activated lymphocytes migrating on intercellular adhesion molecule-1 (ICAM-1, which is one of the major endothelial ligands for migrating leukocytes. SHARPIN-deficient cells adhere better to ICAM-1 and show highly elongated tails when migrating. The increased tail lifetime in SHARPIN-deficient lymphocytes decreases the migration velocity. The adhesion, migration, and uropod defects in SHARPIN-deficient lymphocytes were rescued by reintroducing SHARPIN into the cells. Mechanistically, we show that SHARPIN interacts directly with lymphocyte-function-associated antigen-1 (LFA-1, a leukocyte counterreceptor for ICAM-1, and inhibits the expression of intermediate and high-affinity forms of LFA-1. Thus, SHARPIN controls lymphocyte migration by endogenously maintaining LFA-1 inactive to allow adjustable detachment of the uropods in polarized cells.

  2. Constitutively active ezrin increases membrane tension, slows migration, and impedes endothelial transmigration of lymphocytes in vivo in mice.

    Science.gov (United States)

    Liu, Yin; Belkina, Natalya V; Park, Chung; Nambiar, Raj; Loughhead, Scott M; Patino-Lopez, Genaro; Ben-Aissa, Khadija; Hao, Jian-Jiang; Kruhlak, Michael J; Qi, Hai; von Andrian, Ulrich H; Kehrl, John H; Tyska, Matthew J; Shaw, Stephen

    2012-01-12

    ERM (ezrin, radixin moesin) proteins in lymphocytes link cortical actin to plasma membrane, which is regulated in part by ERM protein phosphorylation. To assess whether phosphorylation of ERM proteins regulates lymphocyte migration and membrane tension, we generated transgenic mice whose T-lymphocytes express low levels of ezrin phosphomimetic protein (T567E). In these mice, T-cell number in lymph nodes was reduced by 27%. Lymphocyte migration rate in vitro and in vivo in lymph nodes decreased by 18% to 47%. Lymphocyte membrane tension increased by 71%. Investigations of other possible underlying mechanisms revealed impaired chemokine-induced shape change/lamellipod extension and increased integrin-mediated adhesion. Notably, lymphocyte homing to lymph nodes was decreased by 30%. Unlike most described homing defects, there was not impaired rolling or sticking to lymph node vascular endothelium but rather decreased migration across that endothelium. Moreover, decreased numbers of transgenic T cells in efferent lymph suggested defective egress. These studies confirm the critical role of ERM dephosphorylation in regulating lymphocyte migration and transmigration. Of particular note, they identify phospho-ERM as the first described regulator of lymphocyte membrane tension, whose increase probably contributes to the multiple defects observed in the ezrin T567E transgenic mice.

  3. Integrin-mediated signal transduction linked to Ras pathway by GRB2 binding to focal adhesion kinase.

    Science.gov (United States)

    Schlaepfer, D D; Hanks, S K; Hunter, T; van der Geer, P

    The cytoplasmic focal adhesion protein-tyrosine kinase (FAK) localizes with surface integrin receptors at sites where cells attach to the extracellular matrix. Increased FAK tyrosine phosphorylation occurs upon integrin engagement with fibronectin. Here we show that adhesion of murine NIH3T3 fibroblasts to fibronectin promotes SH2-domain-mediated association of the GRB2 adaptor protein and the c-Src protein-tyrosine kinase (PTK) with FAK in vivo, and also results in activation of mitogen-activated protein kinase (MAPK). In v-Src-transformed NIH3T3, the association of v-Src, GRB2 and Sos with FAK is independent of cell adhesion to fibronectin. The GRB2 SH2 domain binds directly to tyrosine-phosphorylated FAK. Mutation of tyrosine residue 925 of FAK (YENV motif) to phenylalanine blocks GRB2 SH2-domain binding to FAK in vitro. Our results show that fibronectin binding to integrins on NIH3T3 fibroblasts promotes c-Src and FAK association and formation of an integrin-activated signalling complex. Phosphorylation of FAK at Tyr 925 upon fibronectin stimulation creates an SH2-binding site for GRB2 which may link integrin engagement to the activation of the Ras/MAPK signal transduction pathway.

  4. CD177 modulates human neutrophil migration through activation-mediated integrin and chemoreceptor regulation.

    Science.gov (United States)

    Bai, Ming; Grieshaber-Bouyer, Ricardo; Wang, Junxia; Schmider, Angela B; Wilson, Zachary S; Zeng, Liling; Halyabar, Olha; Godin, Matthew D; Nguyen, Hung N; Levescot, Anaïs; Cunin, Pierre; Lefort, Craig T; Soberman, Roy J; Nigrovic, Peter A

    2017-11-09

    CD177 is a glycosylphosphatidylinositol (GPI)-anchored protein expressed by a variable proportion of human neutrophils that mediates surface expression of the antineutrophil cytoplasmic antibody antigen proteinase 3. CD177 associates with β2 integrins and recognizes platelet endothelial cell adhesion molecule 1 (PECAM-1), suggesting a role in neutrophil migration. However, CD177 pos neutrophils exhibit no clear migratory advantage in vivo, despite interruption of in vitro transendothelial migration by CD177 ligation. We sought to understand this paradox. Using a PECAM-1-independent transwell system, we found that CD177 pos and CD177 neg neutrophils migrated comparably. CD177 ligation selectively impaired migration of CD177 pos neutrophils, an effect mediated through immobilization and cellular spreading on the transwell membrane. Correspondingly, CD177 ligation enhanced its interaction with β2 integrins, as revealed by fluorescence lifetime imaging microscopy, leading to integrin-mediated phosphorylation of Src and extracellular signal-regulated kinase (ERK). CD177-driven cell activation enhanced surface β2 integrin expression and affinity, impaired internalization of integrin attachments, and resulted in ERK-mediated attenuation of chemokine signaling. We conclude that CD177 signals in a β2 integrin-dependent manner to orchestrate a set of activation-mediated mechanisms that impair human neutrophil migration. © 2017 by The American Society of Hematology.

  5. Mesenchymal stromal cells derived from cervical cancer produce high amounts of adenosine to suppress cytotoxic T lymphocyte functions

    Directory of Open Access Journals (Sweden)

    María de Lourdes Mora-García

    2016-10-01

    Full Text Available Abstract Background In recent years, immunomodulatory mechanisms of mesenchymal stem/stromal cells (MSCs from bone marrow and other “classic” sources have been described. However, the phenotypic and functional properties of tumor MSCs are poorly understood. The aim of this study was to analyze the immunosuppressive capacity of cervical cancer-derived MSCs (CeCa-MSCs on effector T lymphocytes through the purinergic pathway. Methods We determined the expression and functional activity of the membrane-associated ectonucleotidases CD39 and CD73 on CeCa-MSCs and normal cervical tissue-derived MSCs (NCx-MSCs. We also analyzed their immunosuppressive capacity to decrease proliferation, activation and effector cytotoxic T (CD8+ lymphocyte function through the generation of adenosine (Ado. Results We detected that CeCa-MSCs express higher levels of CD39 and CD73 ectonucleotidases in cell membranes compared to NCx-MSCs, and that this feature was associated with the ability to strongly suppress the proliferation, activation and effector functions of cytotoxic T-cells through the generation of large amounts of Ado from the hydrolysis of ATP, ADP and AMP nucleotides. Conclusions This study suggests that CeCa-MSCs play an important role in the suppression of the anti-tumor immune response in CeCa through the purinergic pathway.

  6. Mesenchymal stromal cells derived from cervical cancer produce high amounts of adenosine to suppress cytotoxic T lymphocyte functions.

    Science.gov (United States)

    de Lourdes Mora-García, María; García-Rocha, Rosario; Morales-Ramírez, Omar; Montesinos, Juan José; Weiss-Steider, Benny; Hernández-Montes, Jorge; Ávila-Ibarra, Luis Roberto; Don-López, Christian Azucena; Velasco-Velázquez, Marco Antonio; Gutiérrez-Serrano, Vianey; Monroy-García, Alberto

    2016-10-26

    In recent years, immunomodulatory mechanisms of mesenchymal stem/stromal cells (MSCs) from bone marrow and other "classic" sources have been described. However, the phenotypic and functional properties of tumor MSCs are poorly understood. The aim of this study was to analyze the immunosuppressive capacity of cervical cancer-derived MSCs (CeCa-MSCs) on effector T lymphocytes through the purinergic pathway. We determined the expression and functional activity of the membrane-associated ectonucleotidases CD39 and CD73 on CeCa-MSCs and normal cervical tissue-derived MSCs (NCx-MSCs). We also analyzed their immunosuppressive capacity to decrease proliferation, activation and effector cytotoxic T (CD8+) lymphocyte function through the generation of adenosine (Ado). We detected that CeCa-MSCs express higher levels of CD39 and CD73 ectonucleotidases in cell membranes compared to NCx-MSCs, and that this feature was associated with the ability to strongly suppress the proliferation, activation and effector functions of cytotoxic T-cells through the generation of large amounts of Ado from the hydrolysis of ATP, ADP and AMP nucleotides. This study suggests that CeCa-MSCs play an important role in the suppression of the anti-tumor immune response in CeCa through the purinergic pathway.

  7. T lymphocyte migration: an action movie starring the actin and associated actors

    Directory of Open Access Journals (Sweden)

    Loïc eDupré

    2015-11-01

    Full Text Available The actin cytoskeleton is composed of a dynamic filament meshwork that builds the architecture of the cell to sustain its fundamental properties. This physical structure is characterized by a continuous remodeling, which allows cells to accomplish complex motility steps such as directed migration, crossing of biological barriers and interaction with other cells. T lymphocytes excel in these motility steps to ensure their immune surveillance duties. In particular, actin cytoskeleton remodeling is key to facilitate the journey of T lymphocytes through distinct tissue environments and to tune their stop and go behavior during the scanning of antigen-presenting cells. The molecular mechanisms controlling actin cytoskeleton remodeling during T lymphocyte motility have been only partially unraveled, since the function of many actin regulators has not yet been assessed in these cells. Our review aims to integrate the current knowledge into a comprehensive picture of how the actin cytoskeleton drives T lymphocyte migration. We will present the molecular actors that control actin cytoskeleton remodeling, as well as their role in the different T lymphocyte motile steps. We will also highlight which challenges remain to be addressed experimentally and which approaches appear promising to tackle them.

  8. T Lymphocyte Migration: An Action Movie Starring the Actin and Associated Actors.

    Science.gov (United States)

    Dupré, Loïc; Houmadi, Raïssa; Tang, Catherine; Rey-Barroso, Javier

    2015-01-01

    The actin cytoskeleton is composed of a dynamic filament meshwork that builds the architecture of the cell to sustain its fundamental properties. This physical structure is characterized by a continuous remodeling, which allows cells to accomplish complex motility steps such as directed migration, crossing of biological barriers, and interaction with other cells. T lymphocytes excel in these motility steps to ensure their immune surveillance duties. In particular, actin cytoskeleton remodeling is a key to facilitate the journey of T lymphocytes through distinct tissue environments and to tune their stop and go behavior during the scanning of antigen-presenting cells. The molecular mechanisms controlling actin cytoskeleton remodeling during T lymphocyte motility have been only partially unraveled, since the function of many actin regulators has not yet been assessed in these cells. Our review aims to integrate the current knowledge into a comprehensive picture of how the actin cytoskeleton drives T lymphocyte migration. We will present the molecular actors that control actin cytoskeleton remodeling, as well as their role in the different T lymphocyte motile steps. We will also highlight which challenges remain to be addressed experimentally and which approaches appear promising to tackle them.

  9. Molecular imaging of alpha v beta3 integrin expression in atherosclerotic plaques with a mimetic of RGD peptide grafted to Gd-DTPA.

    Science.gov (United States)

    Burtea, Carmen; Laurent, Sophie; Murariu, Oltea; Rattat, Dirk; Toubeau, Gérard; Verbruggen, Alfons; Vansthertem, David; Vander Elst, Luce; Muller, Robert N

    2008-04-01

    The integrin alpha v beta3 is highly expressed in atherosclerotic plaques by medial and intimal smooth muscle cells and by endothelial cells of angiogenic microvessels. In this study, we have assessed non-invasive molecular magnetic resonance imaging (MRI) of plaque-associated alpha v beta3 integrin expression on transgenic ApoE-/- mice with a low molecular weight peptidomimetic of Arg-Gly-Asp (mimRGD) grafted to gadolinium diethylenetriaminepentaacetate (Gd-DTPA-g-mimRGD). The analogous compound Eu-DTPA-g-mimRGD was employed for an in vivo competition experiment and to confirm the molecular targeting. The specific interaction of mimRGD conjugated to Gd-DTPA or to 99mTc-DTPA with alpha v beta3 integrin was furthermore confirmed on Jurkat T lymphocytes. The mimRGD was synthesized and conjugated to DTPA. DTPA-g-mimRGD was complexed with GdCl3.6H2O, EuCl3.6H2O, or with [99mTc(CO)3(H2O)3]+. MRI evaluation was performed on a 4.7 T Bruker imaging system. Blood pharmacokinetics of Gd-DTPA-g-mimRGD were assessed in Wistar rats and in c57bl/6j mice. The presence of angiogenic blood vessels and the expression of alpha v beta3 integrin were confirmed in aorta specimens by immunohistochemistry. Gd-DTPA-g-mimRGD produced a strong enhancement of the external structures of the aortic wall and of the more profound layers (possibly tunica media and intima). The aortic lumen seemed to be restrained and distorted. Pre-injection of Eu-DTPA-g-mimRGD diminished the Gd-DTPA-g-mimRGD binding to atherosclerotic plaque and confirmed the specific molecular targeting. A slower blood clearance was observed for Gd-DTPA-g-mimRGD, as indicated by a prolonged elimination half-life and a diminished total clearance. The new compound is potentially useful for the diagnosis of vulnerable atherosclerotic plaques and of other pathologies characterized by alpha v beta3 integrin expression, such as cancer and inflammation. The delayed blood clearance, the significant enhancement of the signal

  10. Chronic lymphocytic leukemia: concepts and observations

    Energy Technology Data Exchange (ETDEWEB)

    Chandra, P.; Chanana, A.D.; Chikkappa, G.; Cronkite, E.P.

    1977-01-01

    Thirty-five patients with chronic lymphocytic leukemia (CLL) were studied for assessment of total body leukemic mass and abnormality in T-lymphocyte function associated with clinical stages of CLL. Total body potassium (TBK), an indicator of lean body mass, was found to correlate well with increase in the clinical stage of the disease. Use of TBK for monitoring the regression and relapse of leukemic load is suggested. No correlation was found between whole cell and nuclear volumes of lymphocytes in CLL patients and clinical stages of the disease. Blast transformation and proliferation under phytohemagglutinin (PHA) stimulation appeared to be normal in purified T cells of early stages and abnormal in the late stages of disease.

  11. Investigation of effects of a new integrin inhibitor and of its association with radiotherapy on paediatric glioma cell lines; etude des effets d'un nouvel inhibiteur d'integrines et de son association avec la radiotherapie sur des lignees de gliomes pediatriques

    Energy Technology Data Exchange (ETDEWEB)

    Le Tinier, F.; Meignan, S.; Leblond, P.; Dewitte, A.; Wattez, N.; Lartigau, E.; Lansiaux, A. [Centre Oscar-Lambret, Lille (France)

    2011-10-15

    The authors report the investigation of the effects of Cilengitide (an integrin inhibitor) alone or in association with ionizing radiation on paediatric glioma cell lines. Five grade-II to IV paediatric glioma cell lines and one high grade adult glioma cell line have been studied. It appears that Cilengitide has a direct effect on paediatric glioma cells, notably before irradiation. Short communication

  12. Endocytosis of Integrin-Binding Human Picornaviruses

    Directory of Open Access Journals (Sweden)

    Pirjo Merilahti

    2012-01-01

    Full Text Available Picornaviruses that infect humans form one of the largest virus groups with almost three hundred virus types. They include significant enteroviral pathogens such as rhino-, polio-, echo-, and coxsackieviruses and human parechoviruses that cause wide range of disease symptoms. Despite the economic importance of picornaviruses, there are no antivirals. More than ten cellular receptors are known to participate in picornavirus infection, but experimental evidence of their role in cellular infection has been shown for only about twenty picornavirus types. Three enterovirus types and one parechovirus have experimentally been shown to bind and use integrin receptors in cellular infection. These include coxsackievirus A9 (CV-A9, echovirus 9, and human parechovirus 1 that are among the most common and epidemic human picornaviruses and bind to αV-integrins via RGD motif that resides on virus capsid. In contrast, echovirus 1 (E-1 has no RGD and uses integrin α2β1 as cellular receptor. Endocytosis of CV-A9 has recently been shown to occur via a novel Arf6- and dynamin-dependent pathways, while, contrary to collagen binding, E-1 binds inactive β1 integrin and enters via macropinocytosis. In this paper, we review what is known about receptors and endocytosis of integrin-binding human picornaviruses.

  13. Integrin β1 regulates leiomyoma cytoskeletal integrity and growth

    Science.gov (United States)

    Malik, Minnie; Segars, James; Catherino, William H.

    2014-01-01

    Uterine leiomyomas are characterized by an excessive extracellular matrix, increased mechanical stress, and increased active RhoA. Previously, we observed that mechanical signaling was attenuated in leiomyoma, but the mechanisms responsible remain unclear. Integrins, especially integrin β1, are transmembrane adhesion receptors that couple extracellular matrix stresses to the intracellular cytoskeleton to influence cell proliferation and differentiation. Here we characterized integrin and laminin to signaling in leiomyoma cells. We observed a 2.25 ± 0.32 fold increased expression of integrin β1 in leiomyoma cells, compared to myometrial cells. Antibody-mediated inhibition of integrin β1 led to significant growth inhibition in leiomyoma cells and a loss of cytoskeletal integrity. Specifically, polymerization of actin filaments and formation of focal adhesions were reduced by inhibition of integrin p1. Inhibition of integrin β1 in leiomyoma cells led to 0.81 ± 0.02 fold decrease in active RhoA, and resembled levels found in serum-starved cells. Likewise, inhibition of integrin β1 was accompanied by a decrease in phospho-ERK. Compared to myometrial cells, leiomyoma cells demonstrated increased expression of integrin α6 subunit to laminin receptor (1.91 ± 0.11 fold), and increased expression of laminin 5α (1.52±0.02), laminin 5β (3.06±0.92), and laminin 5γ (1.66 ± 0.06). Of note, leiomyoma cells grown on laminin matrix appear to realign themselves. Taken together, the findings reveal that the attenuated mechanical signaling in leiomyoma cells is accompanied by an increased expression and a dependence on integrin β1 signaling in leiomyoma cells, compared to myometrial cells. PMID:23023061

  14. α6-Integrin alternative splicing: distinct cytoplasmic variants in stem cell fate specification and niche interaction.

    Science.gov (United States)

    Zhou, Zijing; Qu, Jing; He, Li; Peng, Hong; Chen, Ping; Zhou, Yong

    2018-05-02

    α6-Integrin subunit (also known as CD49f) is a stemness signature that has been found on the plasma membrane of more than 30 stem cell populations. A growing body of studies have focused on the critical role of α6-containing integrins (α6β1 and α6β4) in the regulation of stem cell properties, lineage-specific differentiation, and niche interaction. α6-Integrin subunit can be alternatively spliced at the post-transcriptional level, giving rise to divergent isoforms which differ in the cytoplasmic and/or extracellular domains. The cytoplasmic domain of integrins is an important functional part of integrin-mediated signals. Structural changes in the cytoplasmic domain of α6 provide an efficient means for the regulation of stem cell responses to biochemical stimuli and/or biophysical cues in the stem cell niche, thus impacting stem cell fate determination. In this review, we summarize the current knowledge on the structural variants of the α6-integrin subunit and spatiotemporal expression of α6 cytoplasmic variants in embryonic and adult stem/progenitor cells. We highlight the roles of α6 cytoplasmic variants in stem cell fate decision and niche interaction, and discuss the potential mechanisms involved. Understanding of the distinct functions of α6 splicing variants in stem cell biology may inform the rational design of novel stem cell-based therapies for a range of human diseases.

  15. Suppression of bovine lymphocyte function by treatment with physiologic concentrations of cortisone

    Energy Technology Data Exchange (ETDEWEB)

    Ojo-Amaize, E.A.; Paape, M.J.; Guidry, A.J.; Mayer, H.K.

    1986-03-01

    The blastogenic response of peripheral blood lymphocytes (PBL) (8 cows) to capsular antigen extract of Staphylococcus aureus, PHA and LPS was measured in vitro using /sup 5/H-thymidine pulse labelling. isolated PBL were treated in vitro for 6-8 days with 10, 25 and 45 ng/ml cortisone. These concentrations simulate serum corticosteroid levels during environmental stress, acute clinical mastitis and ACTH therapy, respectively. To determine the minimal concentration of cortisone that would induce suppression, PBL were also incubated with increasing concentrations of cortisone starting at 10 pg/ml. All concentrations of cortisone caused a significant (P<0.01) depression of lymphocyte blastogenic response to S. aureus, PHA and LPS. Macrophage depletion experiments showed no macrophage suppressor effects. Both the blastogenic response of untreated peripheral blood lymphocytes to S. aureus, PHA and LPS and the degree to which that response was suppressed by cortisone differed significantly among cows. Results indicate that cortisone levels found during physiological stress and after therapeutic administration of ACTH can suppress lymphocyte function.

  16. Defective immunoregulatory T-cell function in chronic lymphocytic leukemia

    International Nuclear Information System (INIS)

    Han, T.; Ozer, H.; Henderson, E.S.; Dadey, B.; Nussbaum-Blumenson, A.; Barcos, M.

    1981-01-01

    Chronic lymphocytic leukemia (CLL) of B-cell origin results in the malignant proliferation of small immunoglobulin-bearing lymphocytes. There is currently a controversy in the literature regarding both the ability of this leukemic population to differentiate into mature plasma cells, as well as the ability of apparently normal T cells from these patients to regulate allogeneic B-cell differentiation. In the present study we have examined the lymphocytes of CLL patients in various clinical stages of their disease and with different surface phenotypes of their leukemic B-cell population. Our results show that leukemic CLL B cells from all 20 patients (including one patient with a monoclonal IgM paraprotein and another with a monoclonal IgG paraprotein) are incapable of further differentiation even in the absence of suppressor T cells and the presence of helper T lymphocytes. This lack of capacity to differentiate is unaffected by clinical stage, by therapy, or by the phenotype of the malignant population. Since the leukemic B population did not suppress normal allogeneic B-cell differentiation, the maturation deficit is evidently intrinsic to the leukemic clone rather than a result of activity of non-T suppressor cells. T helper function was also variably depressed in the blood of some patients with CLL, and this depression did not correlate with clinical stage, with therapy, or with the degree of lymphocytosis. Dysfunction of radiosensitive T suppressor cells was found to be the most consistent regulatory deficit of CLL T cells. Each of 11 patients whose leukemic cell population was of the μdelta, μα, or μ phenotype had both helper and suppressor cell defects

  17. Oncofetal chondroitin sulfate glycosaminoglycans are key players in integrin signaling and tumor cell motility

    DEFF Research Database (Denmark)

    Clausen, Thomas Mandel; Bento Ayres Pereira, Marina Maria; Al Nakouzi, Nader

    2016-01-01

    Many tumors express proteoglycans modified with oncofetal chondroitin sulfate glycosaminoglycan chains (ofCS), which are normally restricted to the placenta. However, the role of ofCS in cancer is largely unknown. The function of ofCS in cancer was analyzed using the recombinant ofCS-binding VAR2...... revealed an overrepresentation of proteins involved in cell motility and integrin signaling, such as integrin-β1 (ITGB1) and integrin-α4 (ITGA4). Saturating concentrations of rVAR2 inhibited downstream integrin signaling, which was mimicked by knockdown of the core chondroitin sulfate synthesis enzymes β-1......,3-glucuronyltransferase 1 (B3GAT1) and chondroitin sulfate N-acetylgalactosaminyltransferase 1 (CSGALNACT1). The ofCS modification was highly expressed in both human and murine metastatic lesions in situ and preincubation or early intravenous treatment of tumor cells with rVAR2 inhibited seeding and spreading of tumor...

  18. Ligand-Occupied Integrin Internalization Links Nutrient Signaling to Invasive Migration

    Directory of Open Access Journals (Sweden)

    Elena Rainero

    2015-01-01

    Full Text Available Integrin trafficking is key to cell migration, but little is known about the spatiotemporal organization of integrin endocytosis. Here, we show that α5β1 integrin undergoes tensin-dependent centripetal movement from the cell periphery to populate adhesions located under the nucleus. From here, ligand-engaged α5β1 integrins are internalized under control of the Arf subfamily GTPase, Arf4, and are trafficked to nearby late endosomes/lysosomes. Suppression of centripetal movement or Arf4-dependent endocytosis disrupts flow of ligand-bound integrins to late endosomes/lysosomes and their degradation within this compartment. Arf4-dependent integrin internalization is required for proper lysosome positioning and for recruitment and activation of mTOR at this cellular subcompartment. Furthermore, nutrient depletion promotes subnuclear accumulation and endocytosis of ligand-engaged α5β1 integrins via inhibition of mTORC1. This two-way regulatory interaction between mTORC1 and integrin trafficking in combination with data describing a role for tensin in invasive cell migration indicate interesting links between nutrient signaling and metastasis.

  19. Laminin isoforms differentially regulate adhesion, spreading, proliferation, and ERK activation of β1 integrin-null cells

    International Nuclear Information System (INIS)

    Kikkawa, Yamato; Yu, Hao; Genersch, Elke; Sanzen, Noriko; Sekiguchi, Kiyotoshi; Faessler, Reinhard; Campbell, Kevin P.; Talts, Jan F.; Ekblom, Peter

    2004-01-01

    The presence of many laminin receptors of the β1 integrin family on most cells makes it difficult to define the biological functions of other major laminin receptors such as integrin α6β4 and dystroglycan. We therefore tested the binding of a β1 integrin-null cell line GD25 to four different laminin variants. The cells were shown to produce dystroglycan, which based on affinity chromatography bound to laminin-1, -2/4, and -10/11, but not to laminin-5. The cells also expressed the integrin α6Aβ4A variant. GD25 β1 integrin-null cells are known to bind poorly to laminin-1, but we demonstrate here that these cells bind avidly to laminin-2/4, -5, and -10/11. The initial binding at 20 min to each of these laminins could be inhibited by an integrin α6 antibody, but not by a dystroglycan antibody. Hence, integrin α6Aβ4A of GD25 cells was identified as a major receptor for initial GD25 cell adhesion to three out of four tested laminin isoforms. Remarkably, cell adhesion to laminin-5 failed to promote cell spreading, proliferation, and extracellular signal-regulated kinase (ERK) activation, whereas all these responses occurred in response to adhesion to laminin-2/4 or -10/11. The data establish GD25 cells as useful tools to define the role integrin α6Aβ4A and suggest that laminin isoforms have distinctly different capacities to promote cell adhesion and signaling via integrin α6Aβ4A

  20. Ca2+-dependent localization of integrin-linked kinase to cell junctions in differentiating keratinocytes.

    Science.gov (United States)

    Vespa, Alisa; Darmon, Alison J; Turner, Christopher E; D'Souza, Sudhir J A; Dagnino, Lina

    2003-03-28

    Integrin complexes are necessary for proper proliferation and differentiation of epidermal keratinocytes. Differentiation of these cells is accompanied by down-regulation of integrins and focal adhesions as well as formation of intercellular adherens junctions through E-cadherin homodimerization. A central component of integrin adhesion complexes is integrin-linked kinase (ILK), which can induce loss of E-cadherin expression and epithelial-mesenchymal transformation when ectopically expressed in intestinal and mammary epithelia. In cultured primary mouse keratinocytes, we find that ILK protein levels are independent of integrin expression and signaling, since they remain constant during Ca(2+)-induced differentiation. In contrast, keratinocyte differentiation is accompanied by marked reduction in kinase activity in ILK immunoprecipitates and altered ILK subcellular distribution. Specifically, ILK distributes in close apposition to actin fibers along intercellular junctions in differentiated but not in undifferentiated keratinocytes. ILK localization to cell-cell borders occurs independently of integrin signaling and requires Ca(2+) as well as an intact actin cytoskeleton. Further, and in contrast to what is observed in other epithelial cells, ILK overexpression in differentiated keratinocytes does not promote E-cadherin down-regulation and epithelial-mesenchymal transition. Thus, novel tissue-specific mechanisms control the formation of ILK complexes associated with cell-cell junctions in differentiating murine epidermal keratinocytes.

  1. Bidirectional remodeling of β1-integrin adhesions during chemotropic regulation of nerve growth

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    Carlstrom Lucas P

    2011-11-01

    Full Text Available Abstract Background Chemotropic factors in the extracellular microenvironment guide nerve growth by acting on the growth cone located at the tip of extending axons. Growth cone extension requires the coordination of cytoskeleton-dependent membrane protrusion and dynamic adhesion to the extracellular matrix, yet how chemotropic factors regulate these events remains an outstanding question. We demonstrated previously that the inhibitory factor myelin-associated glycoprotein (MAG triggers endocytic removal of the adhesion receptor β1-integrin from the growth cone surface membrane to negatively remodel substrate adhesions during chemorepulsion. Here, we tested how a neurotrophin might affect integrin adhesions. Results We report that brain-derived neurotropic factor (BDNF positively regulates the formation of substrate adhesions in axonal growth cones during stimulated outgrowth and prevents removal of β1-integrin adhesions by MAG. Treatment of Xenopus spinal neurons with BDNF rapidly triggered β1-integrin clustering and induced the dynamic formation of nascent vinculin-containing adhesion complexes in the growth cone periphery. Both the formation of nascent β1-integrin adhesions and the stimulation of axon extension by BDNF required cytoplasmic calcium ion signaling and integrin activation at the cell surface. Exposure to MAG decreased the number of β1-integrin adhesions in the growth cone during inhibition of axon extension. In contrast, the BDNF-induced adhesions were resistant to negative remodeling by MAG, correlating with the ability of BDNF pretreatment to counteract MAG-inhibition of axon extension. Pre-exposure to MAG prevented the BDNF-induced formation of β1-integrin adhesions and blocked the stimulation of axon extension by BDNF. Conclusions Altogether, these findings demonstrate the neurotrophin-dependent formation of integrin-based adhesions in the growth cone and reveal how a positive regulator of substrate adhesions can block

  2. Genetic analysis of beta1 integrin function: confirmed, new and revised roles for a crucial family of cell adhesion molecules

    DEFF Research Database (Denmark)

    Brakebusch, C; Hirsch, E; Potocnik, A

    1997-01-01

    Integrins are heterodimeric cell adhesion proteins connecting the extracellular matrix to the cytoskeleton and transmitting signals in both directions. These integrins are suggested to be involved in many different biological processes such as growth, differentiation, migration, and cell death. O...

  3. Involvement of lymphocyte function-associated antigen-1 (LFA-1) in HIV infection: inhibition by monoclonal antibody

    DEFF Research Database (Denmark)

    Hansen, J E; Nielsen, C; Mathiesen, Lars Reinhardt

    1991-01-01

    Monoclonal antibodies (MAbs) against the alpha- and beta-chain of lymphocyte-associated antigen-1 (LFA-1) were examined for inhibition of HIV-1 infection in vitro. Infection of the T cell line MT4 and the monocytic cell line U937 by isolates HTLVIIIB and SSI-002, respectively was inhibited...... in a concentration dependent manner by MAb against the beta-chain but not against the alpha-chain. No cross-reactivity was found between MAb against LFA-1 and against the CD4 receptor (MAb Leu3a). MAbs against the beta-chain and the CD4 receptor were found to act synergistically in inhibiting HIV infection...

  4. Beta1 integrins regulate chondrocyte rotation, G1 progression, and cytokinesis

    DEFF Research Database (Denmark)

    Aszodi, Attila; Hunziker, Ernst B; Brakebusch, Cord

    2003-01-01

    Beta1 integrins are highly expressed on chondrocytes, where they mediate adhesion to cartilage matrix proteins. To assess the functions of beta1 integrin during skeletogenesis, we inactivated the beta1 integrin gene in chondrocytes. We show here that these mutant mice develop a chondrodysplasia...... of various severity. beta1-deficient chondrocytes had an abnormal shape and failed to arrange into columns in the growth plate. This is caused by a lack of motility, which is in turn caused by a loss of adhesion to collagen type II, reduced binding to and impaired spreading on fibronectin, and an abnormal F......-actin organization. In addition, mutant chondrocytes show decreased proliferation caused by a defect in G1/S transition and cytokinesis. The G1/S defect is, at least partially, caused by overexpression of Fgfr3, nuclear translocation of Stat1/Stat5a, and up-regulation of the cell cycle inhibitors p16 and p21...

  5. Correlation between Lymphocyte CD4 Count, Treatment Duration, Opportunistic Infection and Cognitive Function in Human Immunodeficiency Virus-Acquired Immunodeficiency Syndrome (HIV-AIDS) Patients.

    Science.gov (United States)

    Fitri, Fasihah Irfani; Rambe, Aldy Safruddin; Fitri, Aida

    2018-04-15

    Human immunodeficiency virus (HIV) infection is an epidemic worldwide, despite the marked benefits of antiretroviral therapy (ARV) in reducing severe HIV-associated dementia. A milder form of neurocognitive disorders are still prevalent and remain a challenge. This study aimed to determine the correlation between plasma cluster of differentiation 4 (CD4) lymphocyte, duration of ARV treatment, opportunistic infections, and cognitive function in HIV-AIDS patients. A cross-sectional study involving 85 HIV-AIDS patients was conducted at Adam Malik General Hospital Medan, Indonesia. All subjects were subjected to physical, neurologic examination and Montreal Cognitive Assessment-Indonesian Version (MoCA-INA) to assess cognitive function and measurement of lymphocyte CD4 counts. Out of the 85 subjects evaluated, the proportion concerning sexes include 52 males (61.2 %) and 33 females (38.8%). The mean age was 38.53 ± 9.77 years old. There was a significant correlation between CD4 lymphocyte counts and MoCA-INA score (r = 0.271, p = 0.012), but there was no significant correlation between duration of ARV treatment and MoCA-INA score. There was also no difference in MoCA-INA score based on the presence of opportunistic infection. Lymphocyte CD4 count was independently correlated with cognitive function in HIV-AIDS patients.

  6. SPARC regulates extracellular matrix organization through its modulation of integrin-linked kinase activity.

    Science.gov (United States)

    Barker, Thomas H; Baneyx, Gretchen; Cardó-Vila, Marina; Workman, Gail A; Weaver, Matt; Menon, Priya M; Dedhar, Shoukat; Rempel, Sandra A; Arap, Wadih; Pasqualini, Renata; Vogel, Viola; Sage, E Helene

    2005-10-28

    SPARC, a 32-kDa matricellular glycoprotein, mediates interactions between cells and their extracellular matrix, and targeted deletion of Sparc results in compromised extracellular matrix in mice. Fibronectin matrix provides provisional tissue scaffolding during development and wound healing and is essential for the stabilization of mature extracellular matrix. Herein, we report that SPARC expression does not significantly affect fibronectin-induced cell spreading but enhances fibronectin-induced stress fiber formation and cell-mediated partial unfolding of fibronectin molecules, an essential process in fibronectin matrix assembly. By phage display, we identify integrin-linked kinase as a potential binding partner of SPARC and verify the interaction by co-immunoprecipitation and colocalization in vitro. Cells lacking SPARC exhibit diminished fibronectin-induced integrin-linked kinase activation and integrin-linked kinase-dependent cell-contractile signaling. Furthermore, induced expression of SPARC in SPARC-null fibroblasts restores fibronectin-induced integrin-linked kinase activation, downstream signaling, and fibronectin unfolding. These data further confirm the function of SPARC in extracellular matrix organization and identify a novel mechanism by which SPARC regulates extracellular matrix assembly.

  7. Diversity, Function and Transcriptional Regulation of Gut Innate Lymphocytes

    Directory of Open Access Journals (Sweden)

    Lucille eRankin

    2013-03-01

    Full Text Available The innate immune system plays a critical early role in host defense against viruses, bacteria and tumour cells. Until recently, natural killer (NK cells and lymphoid tissue inducer (LTi cells were the primary members of the innate lymphocyte family: NK cells form the front-line interface between the external environment and the adaptive immune system, while LTi cells are essential for secondary lymphoid tissue formation. More recently, it has become apparent that the composition of this family is much more diverse than previously appreciated and newly recognized populations play distinct and essential functions in tissue protection. Despite the importance of these cells, the developmental relationships between different innate lymphocyte populations (ILCs remain unclear. Here we review recent advances in our understanding of the development of different innate immune cell subsets, the transcriptional programs that might be involved in driving fate decisions during development, and their relationship to NK cells.

  8. Probiotic-derived polyphosphate enhances the epithelial barrier function and maintains intestinal homeostasis through integrin-p38 MAPK pathway.

    Directory of Open Access Journals (Sweden)

    Shuichi Segawa

    Full Text Available Probiotics exhibit beneficial effects on human health, particularly in the maintenance of intestinal homeostasis in a complex manner notwithstanding the diversity of an intestinal flora between individuals. Thus, it is highly probable that some common molecules secreted by probiotic and/or commensal bacteria contribute to the maintenance of intestinal homeostasis and protect the intestinal epithelium from injurious stimuli. To address this question, we aimed to isolate the cytoprotective compound from a lactobacillus strain, Lactobacillus brevis SBC8803 which possess the ability to induce cytoprotective heat shock proteins in mouse small intestine. L. brevis was incubated in MRS broth and the supernatant was passed through with a 0.2-µm filter. Caco2/bbe cells were treated with the culture supernatant, and HSP27 expression was evaluated by Western blotting. HSP27-inducible components were separated by ammonium sulfate precipitation, DEAE anion exchange chromatography, gel filtration, and HPLC. Finally, we identified that the HSP27-inducible fraction was polyphosphate (poly P, a simple repeated structure of phosphates, which is a common product of lactobacilli and other bacteria associated with intestinal microflora without any definitive physiological functions. Then, poly P was synthesized by poly P-synthesizing enzyme polyphosphate kinase. The synthesized poly P significantly induced HSP27 from Caco2/BBE cells. In addition, Poly P suppressed the oxidant-induced intestinal permeability in the mouse small intestine and pharmacological inhibitors of p38 MAPK and integrins counteract its protective effect. Daily intrarectal administration of poly P (10 µg improved the inflammation grade and survival rate in 4% sodium dextran sulfate-administered mice. This study, for the first time, demonstrated that poly P is the molecule responsible for maintaining intestinal barrier actions which are mediated through the intestinal integrin β1-p38 MAPK.

  9. A diffuse mixed histiocytic-lymphocytic lymphoma associated with immunological abnormalities.

    Science.gov (United States)

    Syrjänen, K J

    1979-01-01

    A diffuse generalized lymphoma histologically classified as mixed histiocytic-lymphocytic type and associated with profound immunologie abnormalities is reported. The patient had an autoimmune hemolytic anemia, an autoimmune thrombocytopenia, polyclonally increased IgG and IgM, polyclonal secretion of kappa and lamda chains into urine, very low serum complement C3 and antibodies against glomerulus and smooth muscle. When studied with the modern surface-marker techniques, the lesion was found to be composed of entirely lymphoid cells of the B-lymphocyte series. The proper classification of this tumor could be a primitive immunoblastic sarcoma. The relationship of the present tumor to the non-neoplastic angioimmunoblastic lymphadenopathia is discussed. The necessity of applying the surface-marker techniques in the classification of malignant lymphomas is emphasized.

  10. Fibronectin-integrin signaling is required for L-glutamine's protection against gut injury.

    Directory of Open Access Journals (Sweden)

    Stefanie Niederlechner

    Full Text Available Extracellular matrix (ECM stabilization and fibronectin (FN-Integrin signaling can mediate cellular protection. L-glutamine (GLN is known to prevent apoptosis after injury. However, it is currently unknown if ECM stabilization and FN-Integrin osmosensing pathways are related to GLN's cell protective mechanism in the intestine.IEC-6 cells were treated with GLN with or without FN siRNA, integrin inhibitor GRGDSP, control peptide GRGESP or ERK1/2 inhibitors PD98059 and UO126 under basal and stressed conditions. Cell survival measured via MTS assay. Phosphorylated and/or total levels of cleaved caspase-3, cleaved PARP, Bax, Bcl-2, heat shock proteins (HSPs, ERK1/2 and transcription factor HSF-1 assessed via Western blotting. Cell size and F-actin morphology quantified by confocal fluorescence microscopy and intracellular GLN concentration by LC-MS/MS.GLN's prevention of FN degradation after hyperthermia attenuated apoptosis. Additionally, inhibition of FN-Integrin interaction by GRGDSP and ERK1/2 kinase inhibition by PD98059 inhibited GLN's protective effect. GRGDSP attenuated GLN-mediated increases in ERK1/2 phosphorylation and HSF-1 levels. PD98059 and GRGDSP also decreased HSP levels after GLN treatment. Finally, GRGDSP attenuated GLN-mediated increases in cell area size and disrupted F-actin assembly, but had no effect on intracellular GLN concentrations.Taken together, this data suggests that prevention of FN degradation and the FN-Integrin signaling play a key role in GLN-mediated cellular protection. GLN's signaling via the FN-Integrin pathway is associated with HSP induction via ERK1/2 and HSF-1 activation leading to reduced apoptosis after gut injury.

  11. Absence of integrin alpha 7 causes a novel form of muscular dystrophy.

    Science.gov (United States)

    Mayer, U; Saher, G; Fässler, R; Bornemann, A; Echtermeyer, F; von der Mark, H; Miosge, N; Pöschl, E; von der Mark, K

    1997-11-01

    Integrin alpha 7 beta 1 is a specific cellular receptor for the basement membrane protein laminin-1 (refs 1,2), as well as for the laminin isoforms -2 and -4 (ref. 3). The alpha 7 subunit is expressed mainly in skeletal and cardiac muscle and has been suggested to be involved in differentiation and migration processes during myogenesis. Three cytoplasmic and two extracellular splice variants that have been described are developmentally regulated and expressed in different sites in the muscle. In adult muscle, the alpha 7A and alpha 7B subunits are concentrated in myotendinous junctions but can also be detected in neuromuscular junctions and along the sarcolemmal membrane. To study the potential involvement of alpha 7 integrin, during myogenesis and its role in muscle integrity and function, we generated a null allele of the alpha 7 gene (Itga7) in the germline of mice by homologous recombination in embryonic stem (ES) cells. Surprisingly, mice homozygous for the mutation are viable and fertile, indicating that the alpha 7 beta 1 integrin is not essential for myogenesis. However, histological analysis of skeletal muscle revealed typical symptoms of a progressive muscular dystrophy starting soon after birth, but with a distinct variability in different muscle types. The observed histopathological changes strongly indicate an impairment of function of the myotendinous junctions. These findings demonstrate that alpha 7 beta 1 integrin represents an indispensable linkage between the muscle fibre and the extracellular matrix that is independent of the dystrophin-dystroglycan complex-mediated interaction of the cytoskeleton with the muscle basement membrane.

  12. Human Parechovirus 1 Infection Occurs via αVβ1 Integrin.

    Directory of Open Access Journals (Sweden)

    Pirjo Merilahti

    Full Text Available Human parechovirus 1 (HPeV-1 (family Picornaviridae is a global cause of pediatric respiratory and CNS infections for which there is no treatment. Although biochemical and in vitro studies have suggested that HPeV-1 binds to αVβ1, αVβ3 and αVβ6 integrin receptor(s, the actual cellular receptors required for infectious entry of HPeV-1 remain unknown. In this paper we analyzed the expression profiles of αVβ1, αVβ3, αVβ6 and α5β1 in susceptible cell lines (A549, HeLa and SW480 to identify which integrin receptors support HPeV-1 internalization and/or replication cycle. We demonstrate by antibody blocking assay, immunofluorescence microscopy and RT-qPCR that HPeV-1 internalizes and replicates in cell lines that express αVβ1 integrin but not αVβ3 or αVβ6 integrins. To further study the role of β1 integrin, we used a mouse cell line, GE11-KO, which is deficient in β1 expression, and its derivate GE11-β1 in which human integrin β1 subunit is overexpressed. HPeV-1 (Harris strain and three clinical HPeV-1 isolates did not internalize into GE11-KO whereas GE11-β1 supported the internalization process. An integrin β1-activating antibody, TS2/16, enhanced HPeV-1 infectivity, but infection occurred in the absence of visible receptor clustering. HPeV-1 also co-localized with β1 integrin on the cell surface, and HPeV-1 and β1 integrin co-endocytosed into the cells. In conclusion, our results demonstrate that in some cell lines the cellular entry of HPeV-1 is primarily mediated by the active form of αVβ1 integrin without visible receptor clustering.

  13. Increased numbers of CD5+ B lymphocytes with a regulatory phenotype in spondylarthritis

    NARCIS (Netherlands)

    Cantaert, Tineke; Doorenspleet, Marieke E.; Francosalinas, Gabriela; Paramarta, Jaqueline E.; Klarenbeek, Paul L.; Tiersma, Yvonne; van der Loos, Chris M.; de Vries, Niek; Tak, Paul Peter; Baeten, Dominique L.

    2012-01-01

    Objective Whether and how B lymphocytes contribute to the pathogenesis of spondylarthritis (SpA), a seronegative arthritis associated with gut inflammation, remains unknown. Because innate-like CD5+ B lymphocytes with regulatory functions have been identified in colitis models, we undertook the

  14. Integrins, muscle agrin and sarcoglycans during muscular inactivity conditions: an immunohistochemical study

    Directory of Open Access Journals (Sweden)

    G Anastasi

    2009-06-01

    Full Text Available Sarcoglycans are transmembrane proteins that seem to be functionally and pathologically as important as dystrophin. Sarcoglycans cluster together to form a complex, which is localized in the cell membrane of skeletal, cardiac, and smooth muscle. It has been proposed that the dystrophin-glycoprotein complex (DGC links the actin cytoskeleton with the extracellular matrix and the proper maintenance of this connection is thought to be crucial to the mechanical stability of the sarcolemma. The integrins are a family of heterodimeric cell surface receptors which play a crucial role in cell adhesion including cell-matrix and intracellular interactions and therefore are involved in various biological phenomena, including cell migration, and differentiation tissue repair. Sarcoglycans and integrins play a mechanical and signaling role stabilizing the systems during cycles of contraction and relaxation.Several studies suggested the possibility that integrins might play a role in muscle agrin signalling. On these basis, we performed an immunohistochemical analyzing sarcoglycans, integrins and agrin, on human skeletal muscle affected by sensitive-motor polyneuropathy, in order to better define the correlation between these proteins and neurogenic atrophy due to peripheral neuropathy. Our results showed the existence of a cascade mechanism which provoke a loss of regulatory effects of muscle activity on costameres, due to loss of muscle and neural agrin.This cascade mechanism could determine a quantitative modification of transmembrane receptors and loss of ?7B could be replaced and reinforced by enhanced expression of the ?7A integrin to restore muscle fiber viability. Second, it is possible that the reduced cycles of contraction and relaxation of muscle fibers, during muscular atrophy, provoke a loss of mechanical stresses transmitted over cell surface receptors that physically couple the cytoskeleton to extracellular matrix. Consequently, these mechanical

  15. The small GTPase, Rap1, mediates CD31-induced integrin adhesion

    NARCIS (Netherlands)

    Reedquist, K. A.; Ross, E.; Koop, E. A.; Wolthuis, R. M.; Zwartkruis, F. J.; van Kooyk, Y.; Salmon, M.; Buckley, C. D.; Bos, J. L.

    2000-01-01

    Integrin-mediated leukocyte adhesion is a critical aspect of leukocyte function that is tightly regulated by diverse stimuli, including chemokines, antigen receptors, and adhesion receptors. How cellular signals from CD31 and other adhesion amplifiers are integrated with those from classical

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

    International Nuclear Information System (INIS)

    Boettiger, D; Wehrle-Haller, B

    2010-01-01

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

  17. Comparative effects of inhaled relatively insoluble forms of 90Y, 144Ce, and 90Sr on canine peripheral lymphocyte function

    International Nuclear Information System (INIS)

    Benjamin, S.A.; Jones, R.K.; Snipes, M.B.; Lustgarten, C.S.

    1976-01-01

    Dogs that have inhaled relatively insoluble forms of either alpha- or beta-emitting radionuclides manifest a peripheral lymphopenia, the development and course of which depends on both total dose and dose rate. The remaining peripheral lymphocytes in dogs exposed to longer lived beta-emitting radionuclides showed a depressed function as measured by the ability to respond to plant mitogens in vitro. This experiment was designed to evaluate the effect of dose rate on peripheral lymphocyte function by exposing dogs to aerosols of radionuclides with varied effective half-lives in the lung: 90 Y (2.6 days), 144 Ce (170 days), and 90 Sr (650 days). Three groups of four adult beagle dogs each were exposed by inhalation to 90 Y, 144 Ce, or 90 Sr in fused-clay particles. Two controls were matched with each group. Initial lung burdens and initial dose rates to the lung were 520 to 610 μCi/kg of body weight and 2200 to 2600 rads/day in the 90 Y group, 33 to 60 μCi/kg and 200 to 350 rads/day in the 144 Ce group, and 25 to 32 μCi/kg and 130 to 170 rads/day in the 90 Sr group. Hematologic parameters and lymphocyte function as measured by the ability of lymphocytes to respond to plant mitogen stimulation were evaluated on a weekly or biweekly basis for 8 weeks after exposure and on a monthly basis thereafter. The 90 Y-exposed dogs showed a marked lymphopenia within 1 week with a return to control levels by 20 weeks after exposure. The remaining peripheral lymphocytes, however, showed no functional changes in these dogs. Animals exposed to 144 Ce or 90 Sr developed a progressive and persisent lymphopenia and showed functional depression of the remaining lymphocytes as well. The relationships among dose pattern, lymphopenia, and lymphocyte-function depression are discussed

  18. IGF-IR promotes prostate cancer growth by stabilizing α5β1 integrin protein levels.

    Directory of Open Access Journals (Sweden)

    Aejaz Sayeed

    Full Text Available Dynamic crosstalk between growth factor receptors, cell adhesion molecules and extracellular matrix is essential for cancer cell migration and invasion. Integrins are transmembrane receptors that bind extracellular matrix proteins and enable cell adhesion and cytoskeletal organization. They also mediate signal transduction to regulate cell proliferation and survival. The type 1 insulin-like growth factor receptor (IGF-IR mediates tumor cell growth, adhesion and inhibition of apoptosis in several types of cancer. We have previously demonstrated that β1 integrins regulate anchorage-independent growth of prostate cancer (PrCa cells by regulating IGF-IR expression and androgen receptor-mediated transcriptional functions. Furthermore, we have recently reported that IGF-IR regulates the expression of β1 integrins in PrCa cells. We have dissected the mechanism through which IGF-IR regulates β1 integrin expression in PrCa. Here we report that IGF-IR is crucial for PrCa cell growth and that β1 integrins contribute to the regulation of proliferation by IGF-IR. We demonstrate that β1 integrin regulation by IGF-IR does not occur at the mRNA level. Exogenous expression of a CD4 - β1 integrin cytoplasmic domain chimera does not interfere with such regulation and fails to stabilize β1 integrin expression in the absence of IGF-IR. This appears to be due to the lack of interaction between the β1 cytoplasmic domain and IGF-IR. We demonstrate that IGF-IR stabilizes the β1 subunit by protecting it from proteasomal degradation. The α5 subunit, one of the binding partners of β1, is also downregulated along with β1 upon IGF-IR knockdown while no change is observed in the expression of the α2, α3, α4, α6 and α7 subunits. Our results reveal a crucial mechanistic role for the α5β1 integrin, downstream of IGF-IR, in regulating cancer growth.

  19. Indium-111 labeling of leukocytes: a detrimental effect on neutrophil and lymphocyte function and an improved method of cell labelling

    International Nuclear Information System (INIS)

    Segal, A.W.; Deteix, P.; Garcia, R.; Tooth, P.; Zanelli, G.D.; Allison, A.C.

    1978-01-01

    A technique for the labeling of cells with the gamma emitter indium-111 has recently been developed. In this study the effects of the labeling procedure on some in vitro functions of human neutrophils and lymphocytes were investigated. With the standard labeling procedure, neutrophil chemotaxis was reduced to approximately 50% of normal and lymphocytes lost surface receptors and failed to respond to stimulation with phytohemagglutinin. The 8-hydroxyquinoline that is used to chelate the indium is toxic to lymphocytes; accordingly the relationship between the quantity of oxine, the chelation of indium, and cell labeling were investigated. Optimal conditions for In-111 cell labeling were established: 100 million cells in 10 ml Hanks' balanced salt solution are mixed with 5 μg of oxine in a mixture of 50 μl of ethanol and 200 μl of saline; they are incubated at 37 0 C for 10 min and then washed. Initially, neutrophils and lymphocytes appear functionally normal, but after 24 to 48 hr lymphocyte function is impaired as a result of radiation damage. This toxicity may limit studies by external scanning on the distribution and kinetics of lymphocytes labeled with In-111

  20. The impact of quercetin on wound healing relates to changes in αV and β1 integrin expression.

    Science.gov (United States)

    Doersch, Karen M; Newell-Rogers, M Karen

    2017-08-01

    Overly fibrotic wound healing can lead to excess scar formation, causing functional impairment and undesirable cosmetic results. However, there are few successful treatments available to prevent or remediate scars. This study sought to explore the molecular mechanisms by which quercetin, a naturally-occurring antifibrotic agent, diminishes scar formation. Using both mice and fibroblast cells, we examined quercetin's impact on fibrosis and the wound healing rate, and potential molecular mechanisms underlying the quercetin-mediated reduction of fibrosis. While cultured fibroblasts demonstrated normal growth in response to quercetin, quercetin increased surface αV integrin and decreased β1 integrin. These changes in surface integrin expression may impact factors that contribute to fibrosis including cell migration, proliferation, and extracellular matrix production. In both quercetin-treated and control mice, wounds healed in about 14 days. Masson's trichrome stain revealed diminished fibrosis at the wound site in quercetin-treated animals despite the normal healing rate, indicating the potential for better cosmetic results without delaying healing. An in vitro scratch wound model using cells plated on an artificial extracellular matrix demonstrated delayed closure following quercetin treatment. The extracellular matrix also ameliorated quercetin's effect on αV integrin. Thus, αV integrin recruitment in response to quercetin treatment may promote the quercetin-mediated decrease extracellular matrix because cells require less extracellular matrix to migrate into a wound. With added extracellular matrix, β1 integrin remained diminished in response to quercetin, indicating that quercetin's effect on β1 integrin expression is independent of extracellular matrix -mediated signaling and is likely driven by inhibition of the intracellular mechanisms driving β1 expression. These findings suggest that quercetin could alter the cells' interactions with the extracellular

  1. Canine chondrodysplasia caused by a truncating mutation in collagen-binding integrin alpha subunit 10.

    Directory of Open Access Journals (Sweden)

    Kaisa Kyöstilä

    Full Text Available The skeletal dysplasias are disorders of the bone and cartilage tissues. Similarly to humans, several dog breeds have been reported to suffer from different types of genetic skeletal disorders. We have studied the molecular genetic background of an autosomal recessive chondrodysplasia that affects the Norwegian Elkhound and Karelian Bear Dog breeds. The affected dogs suffer from disproportionate short stature dwarfism of varying severity. Through a genome-wide approach, we mapped the chondrodysplasia locus to a 2-Mb region on canine chromosome 17 in nine affected and nine healthy Elkhounds (praw = 7.42×10(-6, pgenome-wide = 0.013. The associated locus contained a promising candidate gene, cartilage specific integrin alpha 10 (ITGA10, and mutation screening of its 30 exons revealed a nonsense mutation in exon 16 (c.2083C>T; p.Arg695* that segregated fully with the disease in both breeds (p = 2.5×10(-23. A 24% mutation carrier frequency was indicated in NEs and an 8% frequency in KBDs. The ITGA10 gene product, integrin receptor α10-subunit combines into a collagen-binding α10β1 integrin receptor, which is expressed in cartilage chondrocytes and mediates chondrocyte-matrix interactions during endochondral ossification. As a consequence of the nonsense mutation, the α10-protein was not detected in the affected cartilage tissue. The canine phenotype highlights the importance of the α10β1 integrin in bone growth, and the large animal model could be utilized to further delineate its specific functions. Finally, this study revealed a candidate gene for human chondrodysplasias and enabled the development of a genetic test for breeding purposes to eradicate the disease from the two dog breeds.

  2. DOCK8 is critical for the survival and function of NKT cells.

    Science.gov (United States)

    Crawford, Greg; Enders, Anselm; Gileadi, Uzi; Stankovic, Sanda; Zhang, Qian; Lambe, Teresa; Crockford, Tanya L; Lockstone, Helen E; Freeman, Alexandra; Arkwright, Peter D; Smart, Joanne M; Ma, Cindy S; Tangye, Stuart G; Goodnow, Christopher C; Cerundolo, Vincenzo; Godfrey, Dale I; Su, Helen C; Randall, Katrina L; Cornall, Richard J

    2013-09-19

    Patients with the dedicator of cytokinesis 8 (DOCK8) immunodeficiency syndrome suffer from recurrent viral and bacterial infections, hyper-immunoglobulin E levels, eczema, and greater susceptibility to cancer. Because natural killer T (NKT) cells have been implicated in these diseases, we asked if these cells were affected by DOCK8 deficiency. Using a mouse model, we found that DOCK8 deficiency resulted in impaired NKT cell development, principally affecting the formation and survival of long-lived, differentiated NKT cells. In the thymus, DOCK8-deficient mice lack a terminally differentiated subset of NK1.1(+) NKT cells expressing the integrin CD103, whereas in the liver, DOCK8-deficient NKT cells express reduced levels of the prosurvival factor B-cell lymphoma 2 and the integrin lymphocyte function-associated antigen 1. Although the initial NKT cell response to antigen is intact in the absence of DOCK8, their ongoing proliferative and cytokine responses are impaired. Importantly, a similar defect in NKT cell numbers was detected in DOCK8-deficient humans, highlighting the relevance of the mouse model. In conclusion, our data demonstrate that DOCK8 is required for the development and survival of mature NKT cells, consistent with the idea that DOCK8 mediates survival signals within a specialized niche. Accordingly, impaired NKT cell numbers and function are likely to contribute to the susceptibility of DOCK8-deficient patients to recurrent infections and malignant disease.

  3. DOCK8 is critical for the survival and function of NKT cells

    Science.gov (United States)

    Crawford, Greg; Enders, Anselm; Gileadi, Uzi; Stankovic, Sanda; Zhang, Qian; Lambe, Teresa; Crockford, Tanya L.; Lockstone, Helen E.; Freeman, Alexandra; Arkwright, Peter D.; Smart, Joanne M.; Ma, Cindy S.; Tangye, Stuart G.; Goodnow, Christopher C.; Cerundolo, Vincenzo; Godfrey, Dale I.; Su, Helen C.; Randall, Katrina L.

    2013-01-01

    Patients with the dedicator of cytokinesis 8 (DOCK8) immunodeficiency syndrome suffer from recurrent viral and bacterial infections, hyper–immunoglobulin E levels, eczema, and greater susceptibility to cancer. Because natural killer T (NKT) cells have been implicated in these diseases, we asked if these cells were affected by DOCK8 deficiency. Using a mouse model, we found that DOCK8 deficiency resulted in impaired NKT cell development, principally affecting the formation and survival of long-lived, differentiated NKT cells. In the thymus, DOCK8-deficient mice lack a terminally differentiated subset of NK1.1+ NKT cells expressing the integrin CD103, whereas in the liver, DOCK8-deficient NKT cells express reduced levels of the prosurvival factor B-cell lymphoma 2 and the integrin lymphocyte function-associated antigen 1. Although the initial NKT cell response to antigen is intact in the absence of DOCK8, their ongoing proliferative and cytokine responses are impaired. Importantly, a similar defect in NKT cell numbers was detected in DOCK8-deficient humans, highlighting the relevance of the mouse model. In conclusion, our data demonstrate that DOCK8 is required for the development and survival of mature NKT cells, consistent with the idea that DOCK8 mediates survival signals within a specialized niche. Accordingly, impaired NKT cell numbers and function are likely to contribute to the susceptibility of DOCK8-deficient patients to recurrent infections and malignant disease. PMID:23929855

  4. PRL-3 promotes the motility, invasion, and metastasis of LoVo colon cancer cells through PRL-3-integrin β1-ERK1/2 and-MMP2 signaling

    Directory of Open Access Journals (Sweden)

    Wu Jian

    2009-11-01

    Full Text Available Abstract Background Phosphatase of regenerating liver-3 (PRL-3 plays a causative role in tumor metastasis, but the underlying mechanisms are not well understood. In our previous study, we observed that PRL-3 could decrease tyrosine phosphorylation of integrin β1 and enhance activation of ERK1/2 in HEK293 cells. Herein we aim to explore the association of PRL-3 with integrin β1 signaling and its functional implications in motility, invasion, and metastasis of colon cancer cell LoVo. Methods Transwell chamber assay and nude mouse model were used to study motility and invasion, and metastsis of LoVo colon cancer cells, respectively. Knockdown of integrin β1 by siRNA or lentivirus were detected with Western blot and RT-PCR. The effect of PRL-3 on integrin β1, ERK1/2, and MMPs that mediate motility, invasion, and metastasis were measured by Western blot, immunofluorencence, co-immunoprecipitation and zymographic assays. Results We demonstrated that PRL-3 associated with integrin β1 and its expression was positively correlated with ERK1/2 phosphorylation in colon cancer tissues. Depletion of integrin β1 with siRNA, not only abrogated the activation of ERK1/2 stimulated by PRL-3, but also abolished PRL-3-induced motility and invasion of LoVo cells in vitro. Similarly, inhibition of ERK1/2 phosphorylation with U0126 or MMP activity with GM6001 also impaired PRL-3-induced invasion. In addition, PRL-3 promoted gelatinolytic activity of MMP2, and this stimulation correlated with decreased TIMP2 expression. Moreover, PRL-3-stimulated lung metastasis of LoVo cells in a nude mouse model was inhibited when integrin β1 expression was interfered with shRNA. Conclusion Our results suggest that PRL-3's roles in motility, invasion, and metastasis in colon cancer are critically controlled by the integrin β1-ERK1/2-MMP2 signaling.

  5. Alterated integrin expression in lichen planopilaris

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    Erriquez Roberta

    2007-02-01

    Full Text Available Abstract Background Lichen planopilaris (LPP is an inflammatory disease characterized by a lymphomononuclear infiltrate surrounding the isthmus and infundibulum of the hair follicle of the scalp, that evolves into atrophic/scarring alopecia. In the active phase of the disease hairs are easily plucked with anagen-like hair-roots. In this study we focused on the expression of integrins and basement membrane components of the hair follicle in active LPP lesions. Methods Scalp biopsies were taken in 10 patients with LPP and in 5 normal controls. Using monoclonal antibodies against α3β1 and α6β4 integrins we showed the expression of these integrins and of the basement membrane components of the hair follicle in active LPP lesions and in healthy scalp skin. Results In the LPP involved areas, α3β1 was distributed in a pericellular pattern, the α6 subunit was present with a basolateral distribution while the β4 subunit showed discontinuous expression at the basal pole and occasionally, basolateral staining of the hair follicle. Conclusion: An altered distribution of the integrins in active LPP lesions can explain the phenomenon of easy pulling-out of the hair with a "gelatinous" root-sheath.

  6. Integrin Activation Contributes to Lower Cisplatin Sensitivity in MV3 Melanoma Cells by Inducing the Wnt Signalling Pathway

    Directory of Open Access Journals (Sweden)

    Maria B. R. Piva

    2017-09-01

    Full Text Available Background: integrins have been associated with the development of chemotherapy resistant tumour cells, mostly those of hematopoietic origin, by mediating the binding to the extracellular matrix. The relevance for solid tumour cells and the underlying mechanisms remain elusive. Methods: using MTT assays, we detected the loss in cisplatin sensitivity of human MV3 melanoma cells upon integrin activation. Underlying cellular pathways were evaluated by flow cytometry. A crosstalk between integrin activation and the canonical wnt signalling pathway was tested by measuring β-catenin activity. Results: MV3 cells display a higher resistance against cisplatin cytotoxicity when cellular integrins were activated by manganese or collagen. Proteome profiler array showed a deregulation of the integrin expression pattern by cisplatin. Integrin activation by manganese induces the phosphorylation of PI3K/AKT. The inhibition of PI3K using BEZ235 strongly increases cell sensitivity to cisplatin, blocking manganese and collagen effects. PI3K/AKT activates wnt signalling by blocking Gsk3-β, which was confirmed by β-catenin up-regulation and nuclear localization. Integrins did not affect E-cadherin expression levels, thus endothelial to mesenchymal transition (EMT can be excluded. Conclusion: This is the first report on an integrin/wnt signalling activation axis addressing the consequences for chemotherapy sensitiveness of melanoma cells, which thus offers novel therapeutic targets for approaches to interfere with chemoresistance.

  7. Integrins as Therapeutic Targets: Successes and Cancers

    Directory of Open Access Journals (Sweden)

    Sabine Raab-Westphal

    2017-08-01

    Full Text Available Integrins are transmembrane receptors that are central to the biology of many human pathologies. Classically mediating cell-extracellular matrix and cell-cell interaction, and with an emerging role as local activators of TGFβ, they influence cancer, fibrosis, thrombosis and inflammation. Their ligand binding and some regulatory sites are extracellular and sensitive to pharmacological intervention, as proven by the clinical success of seven drugs targeting them. The six drugs on the market in 2016 generated revenues of some US$3.5 billion, mainly from inhibitors of α4-series integrins. In this review we examine the current developments in integrin therapeutics, especially in cancer, and comment on the health economic implications of these developments.

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

    Science.gov (United States)

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

    2001-01-01

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

  9. Inhibition of Focal Adhesion Kinase Signaling by Integrin α6β1 Supports Human Pluripotent Stem Cell Self-Renewal.

    Science.gov (United States)

    Villa-Diaz, Luis G; Kim, Jin Koo; Laperle, Alex; Palecek, Sean P; Krebsbach, Paul H

    2016-07-01

    Self-renewal of human embryonic stem cells and human induced pluripotent stem cells (hiPSCs)-known as pluripotent stem cells (PSC)-is influenced by culture conditions, including the substrate on which they are grown. However, details of the molecular mechanisms interconnecting the substrate and self-renewal of these cells remain unclear. We describe a signaling pathway in hPSCs linking self-renewal and expression of pluripotency transcription factors to integrin α6β1 and inactivation of focal adhesion kinase (FAK). Disruption of this pathway results in hPSC differentiation. In hPSCs, α6β1 is the dominant integrin and FAK is not phosphorylated at Y397, and thus, it is inactive. During differentiation, integrin α6 levels diminish and Y397 FAK is phosphorylated and activated. During reprogramming of fibroblasts into iPSCs, integrin α6 is upregulated and FAK is inactivated. Knockdown of integrin α6 and activation of β1 integrin lead to FAK phosphorylation and reduction of Nanog, Oct4, and Sox2, suggesting that integrin α6 functions in inactivation of integrin β1 and FAK signaling and prevention of hPSC differentiation. The N-terminal domain of FAK, where Y397 is localized, is in the nuclei of hPSCs interacting with Oct4 and Sox2, and this immunolocalization is regulated by Oct4. hPSCs remodel the extracellular microenvironment and deposit laminin α5, the primary ligand of integrin α6β1. Knockdown of laminin α5 resulted in reduction of integrin α6 expression, phosphorylation of FAK and decreased Oct4. In conclusion, hPSCs promote the expression of integrin α6β1, and nuclear localization and inactivation of FAK to supports stem cell self-renewal. Stem Cells 2016;34:1753-1764. © 2016 AlphaMed Press.

  10. Calreticulin overexpression correlates with integrin-α5 and transforming growth factor-β1 expression in the atria of patients with rheumatic valvular disease and atrial fibrillation.

    Science.gov (United States)

    Zhao, Fei; Zhang, Shijiang; Shao, Yongfeng; Wu, Yanhu; Qin, Jianwei; Chen, Yijiang; Chen, Liang; Gu, Haitao; Wang, Xiaowei; Huang, Chenjun; Zhang, Wei

    2013-10-03

    The aim of this study was to determine whether altered calreticulin expression and distribution contribute to the pathogenesis of atrial fibrillation (AF) associated with valvular heart disease (VHD). AF affects electrophysiological and structural changes that exacerbate AF. Atrial remodeling reportedly underlies AF generation, but the precise mechanism of atrial remodeling in AF remains unclear. Right and left atrial specimens were obtained from 68 patients undergoing valve replacement surgery. The patients were divided into sinus rhythm (SR; n=25), paroxysmal AF (PaAF; n=11), and persistent AF (PeAF; AF lasting >6 months; n=32) groups. Calreticulin, integrin-α5, and transforming growth factor-β1 (TGF-β1) mRNA and protein expression were measured. We also performed immunoprecipitation for calreticulin with either calcineurin B or integrin-α5. Calreticulin, integrin-α5, and TGF-β1 mRNA and protein expression were increased in the AF groups, especially in the left atrium in patients with mitral valve disease. Calreticulin interacted with both calcineurin B and integrin-α5. Integrin-α5 expression correlated with TGF-β1 expression, while calreticulin expression correlated with integrin-α5 and TGF-β1 expression. Despite similar cardiac function classifications, calreticulin expression was greater in the PeAF group than in the SR group. Calreticulin, integrin-α5, and TGF-β1 expression was increased in atrial tissue in patients with AF and was related to AF type, suggesting that calreticulin is involved in the pathogenesis of AF in VHD patients. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  11. Convulxin, a C-type lectin-like protein, inhibits HCASMCs functions via WAD-motif/integrin-αv interaction and NF-κB-independent gene suppression of GRO and IL-8

    Energy Technology Data Exchange (ETDEWEB)

    Shih, Chun-Ho; Chiang, Tin-Bin [Chang Gung University of Science and Technology, Guishan Dist., Taoyuan City, Taiwan (China); Wang, Wen-Jeng, E-mail: wjwang@mail.cgust.edu.tw [Chang Gung University of Science and Technology, Guishan Dist., Taoyuan City, Taiwan (China); Department of Neurological Surgery, Chang Gung Memorial Hospital, Guishan Dist., Taoyuan City, Taiwan (China)

    2017-03-15

    Convulxin (CVX), a C-type lectin-like protein (CLPs), is a potent platelet aggregation inducer. To evaluate its potential applications in angiogenic diseases, the multimeric CVX were further explored on its mode of actions toward human coronary artery smooth muscle cells (HCASMCs). The N-terminus of β-chain of CVX (CVX-β) contains a putative disintegrin-like domain with a conserved motif upon the sequence comparison with other CLPs. Importantly, native CVX had no cytotoxic activity as examined by electrophoretic pattern. A Trp-Ala–Asp (WAD)-containing octapeptide, MTWADAEK, was thereafter synthesized and analyzed in functional assays. In the case of specific integrin antagonists as positive controls, the anti-angiogenic effects of CVX on HCASMCs were investigated by series of functional analyses. CVX showed to exhibit multiple inhibitory activities toward HCASMCs proliferation, adhesion and invasion with a dose- and integrin αvβ3-dependent fashion. However, the WAD-octapeptide exerting a minor potency could also work as an active peptidomimetic. In addition, flow cytometric analysis demonstrated both the intact CVX and synthetic peptide can specifically interact with integrin-αv on HCASMCs and CVX was shown to have a down-regulatory effect on the gene expression of CXC-chemokines, such as growth-related oncogene and interleukin-8. According to nuclear factor-κB (NF-κB) p65 translocation assay and Western blotting analysis, the NF-κB activation was not involved in the signaling events of CVX-induced gene expression. In conclusion, CVX may act as a disintegrin-like protein via the interactions of WAD-motif in CVX-β with integrin-αv on HCASMCs and it also is a gene suppressor with the ability to diminish the expression of two CXC-chemokines in a NF-κB-independent manner. Indeed, more extensive investigations are needed and might create a new avenue for the development of a novel angiostatic agent. - Highlights: • The tetrameric convulxin (CVX) with WAD

  12. Convulxin, a C-type lectin-like protein, inhibits HCASMCs functions via WAD-motif/integrin-αv interaction and NF-κB-independent gene suppression of GRO and IL-8

    International Nuclear Information System (INIS)

    Shih, Chun-Ho; Chiang, Tin-Bin; Wang, Wen-Jeng

    2017-01-01

    Convulxin (CVX), a C-type lectin-like protein (CLPs), is a potent platelet aggregation inducer. To evaluate its potential applications in angiogenic diseases, the multimeric CVX were further explored on its mode of actions toward human coronary artery smooth muscle cells (HCASMCs). The N-terminus of β-chain of CVX (CVX-β) contains a putative disintegrin-like domain with a conserved motif upon the sequence comparison with other CLPs. Importantly, native CVX had no cytotoxic activity as examined by electrophoretic pattern. A Trp-Ala–Asp (WAD)-containing octapeptide, MTWADAEK, was thereafter synthesized and analyzed in functional assays. In the case of specific integrin antagonists as positive controls, the anti-angiogenic effects of CVX on HCASMCs were investigated by series of functional analyses. CVX showed to exhibit multiple inhibitory activities toward HCASMCs proliferation, adhesion and invasion with a dose- and integrin αvβ3-dependent fashion. However, the WAD-octapeptide exerting a minor potency could also work as an active peptidomimetic. In addition, flow cytometric analysis demonstrated both the intact CVX and synthetic peptide can specifically interact with integrin-αv on HCASMCs and CVX was shown to have a down-regulatory effect on the gene expression of CXC-chemokines, such as growth-related oncogene and interleukin-8. According to nuclear factor-κB (NF-κB) p65 translocation assay and Western blotting analysis, the NF-κB activation was not involved in the signaling events of CVX-induced gene expression. In conclusion, CVX may act as a disintegrin-like protein via the interactions of WAD-motif in CVX-β with integrin-αv on HCASMCs and it also is a gene suppressor with the ability to diminish the expression of two CXC-chemokines in a NF-κB-independent manner. Indeed, more extensive investigations are needed and might create a new avenue for the development of a novel angiostatic agent. - Highlights: • The tetrameric convulxin (CVX) with WAD

  13. RAC1 GTP-ase signals Wnt-beta-catenin pathway mediated integrin-directed metastasis-associated tumor cell phenotypes in triple negative breast cancers.

    Science.gov (United States)

    De, Pradip; Carlson, Jennifer H; Jepperson, Tyler; Willis, Scooter; Leyland-Jones, Brian; Dey, Nandini

    2017-01-10

    The acquisition of integrin-directed metastasis-associated (ID-MA) phenotypes by Triple-Negative Breast Cancer (TNBC) cells is caused by an upregulation of the Wnt-beta-catenin pathway (WP). We reported that WP is one of the salient genetic features of TNBC. RAC-GTPases, small G-proteins which transduce signals from cell surface proteins including integrins, have been implicated in tumorigenesis and metastasis by their role in essential cellular functions like motility. The collective percentage of alteration(s) in RAC1 in ER+ve BC was lower as compared to ER-ve BC (35% vs 57%) (brca/tcga/pub2015). High expression of RAC1 was associated with poor outcome for RFS with HR=1.48 [CI: 1.15-1.9] p=0.0019 in the Hungarian ER-veBC cohort. Here we examined how WP signals are transduced via RAC1 in the context of ID-MA phenotypes in TNBC. Using pharmacological agents (sulindac sulfide), genetic tools (beta-catenin siRNA), WP modulators (Wnt-C59, XAV939), RAC1 inhibitors (NSC23766, W56) and WP stimulations (LWnt3ACM, Wnt3A recombinant) in a panel of 6-7 TNBC cell lines, we studied fibronectin-directed (1) migration, (2) matrigel invasion, (3) RAC1 and Cdc42 activation, (4) actin dynamics (confocal microscopy) and (5) podia-parameters. An attenuation of WP, which (a) decreased cellular levels of beta-catenin, as well as its nuclear active-form, (b) decreased fibronectin-induced migration, (c) decreased invasion, (d) altered actin dynamics and (e) decreased podia-parameters was successful in blocking fibronectin-mediated RAC1/Cdc42 activity. Both Wnt-antagonists and RAC1 inhibitors blocked fibronectin-induced RAC1 activation and inhibited the fibronectin-induced ID-MA phenotypes following specific WP stimulation by LWnt3ACM as well as Wnt3A recombinant protein. To test a direct involvement of RAC1-activation in WP-mediated ID-MA phenotypes, we stimulated brain-metastasis specific MDA-MB231BR cells with LWnt3ACM. LWnt3ACM-stimulated fibronectin-directed migration was blocked by

  14. Epitope mapping for monoclonal antibody reveals the activation mechanism for αVβ3 integrin.

    Directory of Open Access Journals (Sweden)

    Tetsuji Kamata

    Full Text Available Epitopes for a panel of anti-αVβ3 monoclonal antibodies (mAbs were investigated to explore the activation mechanism of αVβ3 integrin. Experiments utilizing αV/αIIb domain-swapping chimeras revealed that among the nine mAbs tested, five recognized the ligand-binding β-propeller domain and four recognized the thigh domain, which is the upper leg of the αV chain. Interestingly, the four mAbs included function-blocking as well as non-functional mAbs, although they bound at a distance from the ligand-binding site. The epitopes for these four mAbs were further determined using human-to-mouse αV chimeras. Among the four, P3G8 recognized an amino acid residue, Ser-528, located on the side of the thigh domain, while AMF-7, M9, and P2W7 all recognized a common epitope, Ser-462, that was located close to the α-genu, where integrin makes a sharp bend in the crystal structure. Fibrinogen binding studies for cells expressing wild-type αVβ3 confirmed that AMF-7, M9, and P2W7 were inhibitory, while P3G8 was non-functional. However, these mAbs were all unable to block binding when αVβ3 was constrained in its extended conformation. These results suggest that AMF-7, M9, and P2W7 block ligand binding allosterically by stabilizing the angle of the bend in the bent conformation. Thus, a switchblade-like movement of the integrin leg is indispensable for the affinity regulation of αVβ3 integrin.

  15. The loss of alpha2beta1 integrin suppresses joint inflammation and cartilage destruction in mouse models of rheumatoid arthritis.

    NARCIS (Netherlands)

    Peters, M.E.W.J.; Wendholt, D.; Strietholt, S.; Frank, S.; Pundt, N.; Korb-Pap, A.; Joosten, L.A.B.; Berg, W.B. van den; Kollias, G.; Eckes, B.; Pap, T.

    2012-01-01

    OBJECTIVE: Integrin alpha2beta1 functions as a major receptor for type I collagen on different cell types, including fibroblasts and inflammatory cells. Although in vitro data suggest a role for alpha2beta1 integrin in regulating both cell attachment and expression of matrix-degrading enzymes such

  16. Alpha1 and Alpha2 Integrins Mediate Invasive Activity of Mouse Mammary Carcinoma Cells through Regulation of Stromelysin-1 Expression

    Energy Technology Data Exchange (ETDEWEB)

    Lochter, Andre; Navre, Marc; Werb, Zena; Bissell, Mina J

    1998-06-29

    Tumor cell invasion relies on cell migration and extracellular matrix proteolysis. We investigated the contribution of different integrins to the invasive activity of mouse mammary carcinoma cells. Antibodies against integrin subunits {alpha}6 and {beta}1, but not against {alpha}1 and {alpha}2, inhibited cell locomotion on a reconstituted basement membrane in two-dimensional cell migration assays, whereas antibodies against {beta}1, but not against a6 or {alpha}2, interfered with cell adhesion to basement membrane constituents. Blocking antibodies against {alpha}1 integrins impaired only cell adhesion to type IV collagen. Antibodies against {alpha}1, {alpha}2, {alpha}6, and {beta}1, but not {alpha}5, integrin subunits reduced invasion of a reconstituted basement membrane. Integrins {alpha}1 and {alpha}2, which contributed only marginally to motility and adhesion, regulated proteinase production. Antibodies against {alpha}1 and {alpha}2, but not {alpha}6 and {beta}1, integrin subunits inhibited both transcription and protein expression of the matrix metalloproteinase stromelysin-1. Inhibition of tumor cell invasion by antibodies against {alpha}1 and {alpha}2 was reversed by addition of recombinant stromelysin-1. In contrast, stromelysin-1 could not rescue invasion inhibited by anti-{alpha}6 antibodies. Our data indicate that {alpha}1 and {alpha}2 integrins confer invasive behavior by regulating stromelysin-1 expression, whereas {alpha}6 integrins regulate cell motility. These results provide new insights into the specific functions of integrins during tumor cell invasion.

  17. Phenotypic and Functional Characterization of Peripheral Blood Lymphocytes from Various Age- and Sex-Specific Groups of Owl Monkeys (Aotus nancymaae).

    Science.gov (United States)

    Nehete, Pramod N; Nehete, Bharti P; Chitta, Sriram; Williams, Lawrence E; Abee, Christian R

    2017-02-01

    Owl monkeys (Aotus nancymaae) are New World NHP that serve an important role in vaccine development and as a model for human disease conditions such as malaria. Despite the past contributions of this animal model, limited information is available about the phenotype and functional properties of peripheral blood lymphocytes in reference to sex and age. Using a panel of human antibodies and a set of standardized human immune assays, we identified and characterized various peripheral blood lymphocyte subsets, evaluated the immune functions of T cells, and analyzed cytokines relative to sex and age in healthy owl monkeys. We noted age- and sex-dependent changes in CD28+ (an essential T cell costimulatory molecule) and CD95+ (an apoptotic surface marker) T cells and various levels of cytokines in the plasma. In immune assays of freshly isolated peripheral blood mononuclear cells, IFNγ and perforin responses were significantly higher in female than in male monkeys and in young adults than in juvenile and geriatric groups, despite similar lymphocyte (particularly T cell) populations in these groups. Our current findings may be useful in exploring Aotus monkeys as a model system for the study of aging, susceptibility to infectious diseases, and age-associated differences in vaccine efficacy, and other challenges particular to pediatric and geriatric patients.

  18. Extracellular matrix (ECM)-integrin receptors predict invasive/metastatic propensities in cervical neoplasms

    International Nuclear Information System (INIS)

    Landau-Levin, Mary; Chao, Clifford K.S.

    1996-01-01

    membrane receptors were used. Immunoperoxidase staining was performed. The resulting integrin expression was evaluated by two observers in a blinded fashion. The consensus score (CS) was calculated by the following equation: SC = Σ Pi (i + 1), where i = 1, 2, 3 (indicating weak, moderate, or strong staining) and Pi is the percentage of stained epithelial cells for each intensity, varying from 0 to 100%. Multiple logistic regression was performed to evaluate the association between integrin expression and invasive/metastatic propensity in these four groups. Associations were obtained using Mantel-Hazel correlation and P values were calculated by Fisher's exact test. Results and Conclusions: We found the expression of αv domain was significantly associated with the presence of LNM (P<0.01). Expression of β4 domain decreased in those tumors invading outer third cervical stroma (P<0.02). The correlation between the integrin expression adjusting for other known confounding prognosticators in predicting the aggressiveness of human cervical cancer and the potential clinical application in selecting tumors suitable for radiation therapy will be discussed

  19. Integrin αv in the mechanical response of osteoblast lineage cells

    Energy Technology Data Exchange (ETDEWEB)

    Kaneko, Keiko [Department of Bone and Joint Disease, National Center for Geriatrics and Gerontology, Obu, Aichi 474-8511 (Japan); Ito, Masako [Medical Work-Life-Balance Center, Nagasaki University Hospital, Nagasaki 852-8501 (Japan); Naoe, Yoshinori [Department of Mechanism of Aging, National Center for Geriatrics and Gerontology, Obu, Aichi 474-8511 (Japan); Lacy-Hulbert, Adam [Department of Pediatrics, Massachusetts General Hospital, Boston, MA 02114 (United States); Ikeda, Kyoji, E-mail: kikeda@ncgg.go.jp [Department of Bone and Joint Disease, National Center for Geriatrics and Gerontology, Obu, Aichi 474-8511 (Japan)

    2014-05-02

    Highlights: • Deletion of integrin αv in osteoblast lineage results in an impaired SOST response to loading in vivo. • c-Src–p130Cas–JNK–YAP/TAZ is activated via integrin αv on osteoblasts in response to FSS. • Deletion of integrin αv in osteoblasts results in impaired responses to mechanical stimulation. • Integrin αv is a key component of the mechanosensing machinery in bone. - Abstract: Although osteoblast lineage cells, especially osteocytes, are thought to be a primary mechanosensory cell in bone, the identity of the mechano-receptor and downstream mechano-signaling pathways remain largely unknown. Here we show using osteoblastic cell model of mechanical stimulation with fluid shear stress that in the absence of integrin αv, phosphorylation of the Src substrate p130Cas and JNK was impaired, culminating in an inhibition of nuclear translocation of YAP/TAZ and subsequent transcriptional activation of target genes. Targeted deletion of the integrin αv in osteoblast lineage cells results in an attenuated response to mechanical loading in terms of Sost gene expression, indicative of a role for integrin αv in mechanoreception in vivo. Thus, integrin αv may be integral to a mechanosensing machinery in osteoblastic cells and involved in activation of a Src–JNK–YAP/TAZ pathway in response to mechanical stimulation.

  20. Integrin αv in the mechanical response of osteoblast lineage cells

    International Nuclear Information System (INIS)

    Kaneko, Keiko; Ito, Masako; Naoe, Yoshinori; Lacy-Hulbert, Adam; Ikeda, Kyoji

    2014-01-01

    Highlights: • Deletion of integrin αv in osteoblast lineage results in an impaired SOST response to loading in vivo. • c-Src–p130Cas–JNK–YAP/TAZ is activated via integrin αv on osteoblasts in response to FSS. • Deletion of integrin αv in osteoblasts results in impaired responses to mechanical stimulation. • Integrin αv is a key component of the mechanosensing machinery in bone. - Abstract: Although osteoblast lineage cells, especially osteocytes, are thought to be a primary mechanosensory cell in bone, the identity of the mechano-receptor and downstream mechano-signaling pathways remain largely unknown. Here we show using osteoblastic cell model of mechanical stimulation with fluid shear stress that in the absence of integrin αv, phosphorylation of the Src substrate p130Cas and JNK was impaired, culminating in an inhibition of nuclear translocation of YAP/TAZ and subsequent transcriptional activation of target genes. Targeted deletion of the integrin αv in osteoblast lineage cells results in an attenuated response to mechanical loading in terms of Sost gene expression, indicative of a role for integrin αv in mechanoreception in vivo. Thus, integrin αv may be integral to a mechanosensing machinery in osteoblastic cells and involved in activation of a Src–JNK–YAP/TAZ pathway in response to mechanical stimulation

  1. Integrin-Linked Kinase Is Indispensable for Keratinocyte Differentiation and Epidermal Barrier Function.

    Science.gov (United States)

    Sayedyahossein, Samar; Rudkouskaya, Alena; Leclerc, Valerie; Dagnino, Lina

    2016-02-01

    A functional permeability barrier is essential to prevent the passage of water and electrolytes, macromolecules, and pathogens through the epidermis. This is accomplished in terminally differentiated keratinocytes through formation of a cornified envelope and the assembly of tight intercellular junctions. Integrin-linked kinase (ILK) is a scaffold protein essential for hair follicle morphogenesis and epidermal attachment to the basement membrane. However, the biological functions of ILK in differentiated keratinocytes remain poorly understood. Furthermore, whether ILK is implicated in keratinocyte differentiation and intercellular junction formation has remained an unresolved issue. Here we describe a pivotal role for ILK in keratinocyte differentiation responses to increased extracellular Ca(2+), regulation of adherens and tight junction assembly, and the formation of an outside-in permeability barrier toward macromolecules. In the absence of ILK, the calcium sensing receptor, E-cadherin, and ZO-1 fail to translocate to the cell membrane, through mechanisms that involve abnormalities in microtubules and in RhoA activation. In situ, ILK-deficient epidermis exhibits reduced tight junction formation and increased outside-in permeability to a dextran tracer, indicating reduced barrier properties toward macromolecules. Therefore, ILK is an essential component of keratinocyte differentiation programs that contribute to epidermal integrity and the establishment of its barrier properties. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  2. The effect of conditional inactivation of beta 1 integrins using twist 2 Cre, Osterix Cre and osteocalcin Cre lines on skeletal phenotype.

    Science.gov (United States)

    Shekaran, Asha; Shoemaker, James T; Kavanaugh, Taylor E; Lin, Angela S; LaPlaca, Michelle C; Fan, Yuhong; Guldberg, Robert E; García, Andrés J

    2014-11-01

    Skeletal development and growth are complex processes regulated by multiple microenvironmental cues, including integrin-ECM interactions. The β1 sub-family of integrins is the largest integrin sub-family and constitutes the main integrin binding partners of collagen I, the major ECM component of bone. As complete β1 integrin knockout results in embryonic lethality, studies of β1 integrin function in vivo rely on tissue-specific gene deletions. While multiple in vitro studies indicate that β1 integrins are crucial regulators of osteogenesis and mineralization, in vivo osteoblast-specific perturbations of β1 integrins have resulted in mild and sometimes contradictory skeletal phenotypes. To further investigate the role of β1 integrins on skeletal phenotype, we used the Twist2-Cre, Osterix-Cre and osteocalcin-Cre lines to generate conditional β1 integrin deletions, where Cre is expressed primarily in mesenchymal condensation, pre-osteoblast, and mature osteoblast lineage cells respectively within these lines. Mice with Twist2-specific β1 integrin disruption were smaller, had impaired skeletal development, especially in the craniofacial and vertebral tissues at E19.5, and did not survive beyond birth. Osterix-specific β1 integrin deficiency resulted in viable mice which were normal at birth but displayed early defects in calvarial ossification, incisor eruption and growth as well as femoral bone mineral density, structure, and mechanical properties. Although these defects persisted into adulthood, they became milder with age. Finally, a lack of β1 integrins in mature osteoblasts and osteocytes resulted in minor alterations to femur structure but had no effect on mineral density, biomechanics or fracture healing. Taken together, our data indicate that β1 integrin expression in early mesenchymal condensations play an important role in skeletal ossification, while β1 integrin-ECM interactions in pre-osteoblast, odontoblast- and hypertrophic chondryocyte

  3. The influence of surface integrin binding patterns on specific biomaterial-cell interactions

    Science.gov (United States)

    Beranek, Maggi Marie

    As the future of biomaterials progresses toward bioactivity, the biomaterial surface must control non-specific protein adsorption and encourage selective protein and cell adsorption. Integrins alphavbeta3, alpha 1beta1, alpha5beta1 and alpha Mbeta2 are expressed on cells involved in endothelialization, inflammation, and intimal hyperplasia. These cellular events play a vital role in biomaterial biocompatibility, especially in the vascular environment. The overall hypothesis of these studies is that biomaterial surfaces exhibit selective integrin binding, which then specifies differential cell binding. To test this hypothesis, four specific aims were developed. The first aim was designed to determine whether metal and polymeric biomaterials exhibit selective integrin binding. The tested materials included 316L stainless steel, nitinol, gold, Elgiloy RTM, poly(D, L-lactide-co-glycolide), polycarbonate urethane and expanded polytetrafluoroethylene. Discrete integrin binding patterns were detected microscopically using integrin specific fluorescent antibodies. Stainless steel exhibited high level integrin alpha1beta 1 and low level integrin alphaMbeta2 binding pattern. This suggests that this metal surface should selectively encourage endothelial cell to inflammatory cell binding. In contrast, gold bound ten times the amount of integrin alphaMbeta2 compared to integrin alpha1beta1, which should encourage inflammatory cell adhesion. The 65/35 poly(D, L-lactide-co-glycolide) was the only polymeric biomaterial tested that had integrin binding levels comparable to metal biomaterials. Based on these observations, a combinational biomaterial with a surface pattern of 65/35 poly(D, L-lactide-co-glycolide) dots on a 316L stainless steel background was created. A pattern of high level integrin alpha1beta1 binding and low level integrin alpha Mbeta2 binding on this combinational surface indicates that this surface should selectively favor endothelial cell binding. In the second

  4. Synthesis and biological evaluation of potent alphavbeta3-integrin receptor antagonists.

    NARCIS (Netherlands)

    Dijkgraaf, I.; Kruijtzer, J.A.; Frielink, C.; Soede, A.C.; Hilbers, H.W.; Oyen, W.J.G.; Corstens, F.H.M.; Liskamp, R.M.; Boerman, O.C.

    2006-01-01

    INTRODUCTION: alpha(v)beta(3) Integrin is expressed in sprouting endothelial cells in growing tumors, whereas it is absent in quiescent blood vessels. In addition, various tumor cell types express alpha(v)beta(3) integrin. alpha(v)beta(3) Integrin, a transmembrane heterodimeric protein, binds to the

  5. Beta1 integrins activate a MAPK signalling pathway in neural stem cells that contributes to their maintenance

    DEFF Research Database (Denmark)

    Campos, Lia S; Leone, Dino P; Relvas, Joao B

    2004-01-01

    , signalling is required for neural stem cell maintenance, as assessed by neurosphere formation, and inhibition or genetic ablation of beta1 integrin using cre/lox technology reduces the level of MAPK activity. We conclude that integrins are therefore an important part of the signalling mechanisms that control......The emerging evidence that stem cells develop in specialised niches highlights the potential role of environmental factors in their regulation. Here we examine the role of beta1 integrin/extracellular matrix interactions in neural stem cells. We find high levels of beta1 integrin expression...... in the stem-cell containing regions of the embryonic CNS, with associated expression of the laminin alpha2 chain. Expression levels of laminin alpha2 are reduced in the postnatal CNS, but a population of cells expressing high levels of beta1 remains. Using neurospheres - aggregate cultures, derived from...

  6. Expression of integrin α3β1 and cyclooxygenase-2 (COX2) are positively correlated in human breast cancer

    International Nuclear Information System (INIS)

    Aggarwal, Anshu; Al-Rohil, Rami N; Batra, Anupam; Feustel, Paul J; Jones, David M; DiPersio, C Michael

    2014-01-01

    Expression of integrin α3β1 is associated with tumor progression, metastasis, and poor prognosis in several cancers, including breast cancer. Moreover, preclinical studies have revealed important pro-tumorigenic and pro-metastatic functions for this integrin, including tumor growth, survival, invasion, and paracrine induction of angiogenesis. Our previously published work in a preclinical breast cancer model showed that integrin α3β1 promotes expression of cyclooxygenase-2 (COX2/PTGS2), a known driver of breast cancer progression. However, the clinical significance of this regulation was unknown. The objective of the current study was to assess the clinical relevance of the relationship between integrin α3β1 and COX2 by testing for their correlated expression among various forms of human breast cancer. Immunohistochemistry was performed to assess co-expression of α3 and COX2 in specimens of human invasive ductal carcinoma (IDC), either on a commercial tissue microarray (n = 59 samples) or obtained from Albany Medical Center archives (n = 68 samples). Immunostaining intensity for the integrin α3 subunit or COX2 was scored, and Spearman’s rank correlation coefficient analysis was performed to assess their co-expression across and within different tumor subtypes or clinicopathologic criteria. Although expression of integrin α3 or COX2 varied among clinical IDC samples, a statistically significant, positive correlation was detected between α3 and COX2 in both tissue microarrays (r s = 0.49, p < 0.001, n = 59) and archived samples (r s = 0.59, p < 0.0001, n = 68). In both sample sets, this correlation was independent of hormone receptor status, histological grade, or disease stage. COX2 and α3 are correlated in IDC independently of hormone receptor status or other clinicopathologic features, supporting the hypothesis that integrin α3β1 is a determinant of COX2 expression in human breast cancer. These results support the clinical relevance of α3β1

  7. The effect of γ-tocopherol on proliferation, integrin expression, adhesion, and migration of human glioma cells

    International Nuclear Information System (INIS)

    Samandari, Elika; Visarius, Theresa; Zingg, Jean-Marc; Azzi, Angelo

    2006-01-01

    The effect of vitamin E on proliferation, integrin expression, adhesion, and migration in human glioma cells has been studied. γ-tocopherol at 50 μM concentration exerted more inhibitory effect than α-tocopherol at the same concentration on glioma cell proliferation. Integrin α5 and β1 protein levels were increased upon both α- and γ-tocopherol treatments. In parallel, an increase in the α5β1 heterodimer cell surface expression was observed. The tocopherols inhibited glioma cell-binding to fibronectin where γ-tocopherol treatment induced glioma cell migration. Taken together, the data reported here are consistent with the notion that the inhibition of glioma cell proliferation induced by tocopherols may be mediated, at least in part, by an increase in integrin α5 and β1 expression. Cell adhesion is also negatively affected by tocopherols, despite a small increase in the surface appearance of the α5β1 heterodimer. Cell migration is stimulated by γ-tocopherol. It is concluded that α5 and β1 integrin expression and surface appearance are not sufficient to explain all the observations and that other integrins or in general other factors may be associated with these events

  8. Distinct roles for dystroglycan, beta1 integrin and perlecan in cell surface laminin organization

    DEFF Research Database (Denmark)

    Henry, M D; Satz, J S; Brakebusch, C

    2001-01-01

    Dystroglycan (DG) is a cell surface receptor for several extracellular matrix (ECM) molecules including laminins, agrin and perlecan. Recent data indicate that DG function is required for the formation of basement membranes in early development and the organization of laminin on the cell surface...... integrin-deficient ES cells, laminin-1 binds to the cell surface, but fails to organize into more morphologically complex structures. This result indicates that beta1 integrin function is required after DG function in the cell surface-mediated laminin assembly process. In perlecan-deficient ES cells......, the formation of complex laminin-1 structures is defective, implicating perlecan in the laminin matrix assembly process. Moreover, laminin and perlecan reciprocally modulate the organization of the other on the cell surface. Taken together, the data support a model whereby DG serves as a receptor essential...

  9. The CD157-integrin partnership controls transendothelial migration and adhesion of human monocytes.

    Science.gov (United States)

    Lo Buono, Nicola; Parrotta, Rossella; Morone, Simona; Bovino, Paola; Nacci, Giulia; Ortolan, Erika; Horenstein, Alberto L; Inzhutova, Alona; Ferrero, Enza; Funaro, Ada

    2011-05-27

    CD157, a member of the CD38 gene family, is an NAD-metabolizing ectoenzyme and a signaling molecule whose role in polarization, migration, and diapedesis of human granulocytes has been documented; however, the molecular events underpinning this role remain to be elucidated. This study focused on the role exerted by CD157 in monocyte migration across the endothelial lining and adhesion to extracellular matrix proteins. The results demonstrated that anti-CD157 antibodies block monocyte transmigration and adhesion to fibronectin and fibrinogen but that CD157 cross-linking is sufficient to overcome the block, suggesting an active signaling role for the molecule. Consistent with this is the observation that CD157 is prevalently located within the detergent-resistant membrane microdomains to which, upon clustering, it promotes the recruitment of β(1) and β(2) integrin, which, in turn, leads to the formation of a multimolecular complex favoring signal transduction. This functional cross-talk with integrins allows CD157 to act as a receptor despite its intrinsic structural inability to do so on its own. Intracellular signals mediated by CD157 rely on the integrin/Src/FAK (focal adhesion kinase) pathway, resulting in increased activity of the MAPK/ERK1/2 and the PI3K/Akt downstream signaling pathways, which are crucial in the control of monocyte transendothelial migration. Collectively, these findings indicate that CD157 acts as a molecular organizer of signaling-competent membrane microdomains and that it forms part of a larger molecular machine ruled by integrins. The CD157-integrin partnership provides optimal adhesion and transmigration of human monocytes.

  10. Tumor features and correlation between lymphocyte count and biochemical parameters in patients with hepatitis B virus-associated primary liver cancer with Yin deficiency

    Directory of Open Access Journals (Sweden)

    YANG Zhiyun

    2016-03-01

    Full Text Available ObjectiveTo investigate the tumor features and the correlation between lymphocyte count and biochemical parameters in patients with hepatitis B virus-associated primary liver cancer (PLC with yin deficiency. MethodsA total of 148 PLC patients who were treated in Beijing Ditan Hospital, Capital Medical University, from July 2013 to February 2015 were enrolled and divided into yin-deficiency PLC group (52 patients and non-yin-deficiency PLC group (96 patients. The patients′ general information and laboratory markers were collected, including oncological parameters (alpha-fetoprotein, carcinoembryonic antigen (CEA, and carbohydrate antigen 199 (CA19-9, virological parameter (HBsAg, gross type (nodular type, massive type, bulky type, and diffuse type, radiological features (main portal vein diameter, portal vein tumor thrombus, and extrahepatic metastasis, biochemical parameters (Model for End-Stage Liver Disease (MELD score, white blood cell, red blood cell, platelet (PLT, alanine aminotransferase, aspartate aminotransferase, total bilirubin (TBil, gamma-glutamyl transpeptidase, alkaline phosphatase, albumin, cholinesterase, prothrombin time (PT, and prothrombin time activity (PTA, and lymphocyte count. The t-test was applied for comparison of normally distributed continuous data between groups, and the Pearson correlation analysis was applied for correlation analysis. The Mann-Whitney U test was applied for comparison of non-normally distributed continuous data between groups, and the Spearman correlation analysis was applied for correlation analysis. The chi-square test was applied for comparison of categorical data between groups. ResultsHBsAg showed a significant difference between the two groups (χ2=5.658, P=0.017. Compared with the non-yin-deficiency PLC group, the yin-deficiency PLC group had significantly increased CEA and CA19-9 (U=-2.200 and -2.194, both P<0.05, significantly increased MELD score, TBil, and PT (t=2.2, U=-2.0, U=-2

  11. Osteopontin binding to the alpha 4 integrin requires highest affinity integrin conformation, but is independent of post-translational modifications of osteopontin

    DEFF Research Database (Denmark)

    Hui, Tommy; Sørensen, Esben Skipper; Rittling, Susan R.

    2015-01-01

    Osteopontin (OPN) is a ligand for the α4 integrin, but the physiological importance of this binding is not well understood. Here, we have assessed the effect of posttranslational modifications on OPN binding to the α4 integrin on cultured human leukocyte cell lines, and compared OPN interaction...

  12. Large gradient high magnetic fields affect osteoblast ultrastructure and function by disrupting collagen I or fibronectin/αβ1 integrin.

    Directory of Open Access Journals (Sweden)

    Ai-Rong Qian

    Full Text Available The superconducting magnet generates a field and field gradient product that can levitate diamagnetic materials. In this study a specially designed superconducting magnet with a large gradient high magnetic field (LG-HMF, which can provide three apparent gravity levels (μ-g, 1-g, and 2-g, was used to simulate a space-like gravity environment. The effects of LG-HMF on the ultrastructure and function of osteoblast-like cells (MG-63 and MC3T3-E1 and the underlying mechanism were investigated by transmission electromicroscopy (TEM, MTT, and cell western (ICW assays. Under LG-HMF significant morphologic changes in osteoblast-like cells occurred, including expansion of endoplasmic reticulum and mitochondria, an increased number of lysosomes, distorted microvilli, and aggregates of actin filaments. Compared to controls, cell viability and alkaline phosphatase (ALP secretion were significantly increased, and collagen I (col I, fibronectin (FN, vinculin, integrin α3, αv, and β1 expression were changed under LG-HMF conditions. In conclusion, LG-HMF affects osteoblast ultrastructure, cell viability, and ALP secretion, and the changes caused by LG-HMF may be related to disrupting col I or FN/αβ1 integrin.

  13. Serpine2 deficiency results in lung lymphocyte accumulation and bronchus-associated lymphoid tissue formation.

    Science.gov (United States)

    Solleti, Siva Kumar; Srisuma, Sorachai; Bhattacharya, Soumyaroop; Rangel-Moreno, Javier; Bijli, Kaiser M; Randall, Troy D; Rahman, Arshad; Mariani, Thomas J

    2016-07-01

    Serine proteinase inhibitor, clade E, member 2 (SERPINE2), is a cell- and extracellular matrix-associated inhibitor of thrombin. Although SERPINE2 is a candidate susceptibility gene for chronic obstructive pulmonary disease, the physiologic role of this protease inhibitor in lung development and homeostasis is unknown. We observed spontaneous monocytic-cell infiltration in the lungs of Serpine2-deficient (SE2(-/-)) mice, beginning at or before the time of lung maturity, which resulted in lesions that resembled bronchus-associated lymphoid tissue (BALT). The initiation of lymphocyte accumulation in the lungs of SE2(-/-) mice involved the excessive expression of chemokines, cytokines, and adhesion molecules that are essential for BALT induction, organization, and maintenance. BALT-like lesion formation in the lungs of SE2(-/-) mice was also associated with a significant increase in the activation of thrombin, a recognized target of SE2, and excess stimulation of NF-κB, a major regulator of chemokine expression and inflammation. Finally, systemic delivery of thrombin rapidly stimulated lung chemokine expression in vivo These data uncover a novel mechanism whereby loss of serine protease inhibition leads to lung lymphocyte accumulation.-Solleti, S. K., Srisuma, S., Bhattacharya, S., Rangel-Moreno, J., Bijli, K. M., Randall, T. D., Rahman, A., Mariani, T. J. Serpine2 deficiency results in lung lymphocyte accumulation and bronchus-associated lymphoid tissue formation. © FASEB.

  14. Hydrogels with precisely controlled integrin activation dictate vascular patterning and permeability

    Science.gov (United States)

    Li, Shuoran; Nih, Lina R.; Bachman, Haylee; Fei, Peng; Li, Yilei; Nam, Eunwoo; Dimatteo, Robert; Carmichael, S. Thomas; Barker, Thomas H.; Segura, Tatiana

    2017-09-01

    Integrin binding to bioengineered hydrogel scaffolds is essential for tissue regrowth and regeneration, yet not all integrin binding can lead to tissue repair. Here, we show that through engineering hydrogel materials to promote α3/α5β1 integrin binding, we can promote the formation of a space-filling and mature vasculature compared with hydrogel materials that promote αvβ3 integrin binding. In vitro, α3/α5β1 scaffolds promoted endothelial cells to sprout and branch, forming organized extensive networks that eventually reached and anastomosed with neighbouring branches. In vivo, α3/α5β1 scaffolds delivering vascular endothelial growth factor (VEGF) promoted non-tortuous blood vessel formation and non-leaky blood vessels by 10 days post-stroke. In contrast, materials that promote αvβ3 integrin binding promoted endothelial sprout clumping in vitro and leaky vessels in vivo. This work shows that precisely controlled integrin activation from a biomaterial can be harnessed to direct therapeutic vessel regeneration and reduce VEGF-induced vascular permeability in vivo.

  15. Secondary reduction of alpha7B integrin in laminin alpha2 deficient congenital muscular dystrophy supports an additional transmembrane link in skeletal muscle.

    Science.gov (United States)

    Cohn, R D; Mayer, U; Saher, G; Herrmann, R; van der Flier, A; Sonnenberg, A; Sorokin, L; Voit, T

    1999-03-01

    The integrins are a large family of heterodimeric transmembrane cellular receptors which mediate the association between the extracellular matrix (ECM) and cytoskeletal proteins. The alpha7beta1 integrin is a major laminin binding integrin in skeletal and cardiac muscle and is thought to be involved in myogenic differentiation and migration processes. The main binding partners of the alpha7 integrin are laminin-1 (alpha1-beta1-gamma1), laminin-2 (alpha2-beta1-gamma1) and laminin-4 (alpha2-beta2-gamma1). Targeted deletion of the gene for the alpha7 integrin subunit (ITGA7) in mice leads to a novel form of muscular dystrophy. In the present study we have investigated the expression of two alternative splice variants, the alpha7B and beta1D integrin subunits, in normal human skeletal muscle, as well as in various forms of muscular dystrophy. In normal human skeletal muscle the expression of the alpha7 integrin subunit appeared to be developmentally regulated: it was first detected at 2 years of age. In contrast, the beta1D integrin could be detected in immature and mature muscle in the sarcolemma of normal fetal skeletal muscle at 18 weeks gestation. The expression of alpha7B integrin was significantly reduced at the sarcolemma in six patients with laminin alpha2 chain deficient congenital muscular dystrophy (CMD) (age >2 years). However, this reduction was not correlated with the amount of laminin alpha2 chain expressed. In contrast, the expression of the laminin alpha2 chain was not altered in the skeletal muscle of the alpha7 knock-out mice. These data argue in favor that there is not a tight correlation between the expression of the alpha7 integrin subunit and that of the laminin alpha2 chain in either human or murine dystrophic muscle. Interestingly, in dystrophinopathies (Duchenne and Becker muscular dystrophy; DMD/BMD) expression of alpha7B was upregulated irrespective of the level of dystrophin expression as shown by a strong sarcolemmal staining pattern even

  16. New insights into Blimp-1 in T lymphocytes: a divergent regulator of cell destiny and effector function.

    Science.gov (United States)

    Fu, Shin-Huei; Yeh, Li-Tzu; Chu, Chin-Chen; Yen, B Lin-Ju; Sytwu, Huey-Kang

    2017-07-21

    B lymphocyte-induced maturation protein-1 (Blimp-1) serves as a master regulator of the development and function of antibody-producing B cells. Given that its function in T lymphocytes has been identified within the past decade, we review recent findings with emphasis on its role in coordinated control of gene expression during the development, differentiation, and function of T cells. Expression of Blimp-1 is mainly confined to activated T cells and is essential for the production of interleukin (IL)-10 by a subset of forkhead box (Fox)p3 + regulatory T cells with an effector phenotype. Blimp-1 is also required to induce cell elimination in the thymus and critically modulates peripheral T cell activation and proliferation. In addition, Blimp-1 promotes T helper (Th) 2 lineage commitment and limits Th1, Th17 and follicular helper T cell differentiation. Furthermore, Blimp-1 coordinates with other transcription factors to regulate expression of IL-2, IL-21 and IL-10 in effector T lymphocytes. In CD8 + T cells, Blimp-1 expression is distinct in heterogeneous populations at the stages of clonal expansion, differentiation, contraction and memory formation when they encounter antigens. Moreover, Blimp-1 plays a fundamental role in coordinating cytokine receptor signaling networks and transcriptional programs to regulate diverse aspects of the formation and function of effector and memory CD8 + T cells and their exhaustion. Blimp-1 also functions as a gatekeeper of T cell activation and suppression to prevent or dampen autoimmune disease, antiviral responses and antitumor immunity. In this review, we discuss the emerging roles of Blimp-1 in the complex regulation of gene networks that regulate the destiny and effector function of T cells and provide a Blimp-1-dominated transcriptional framework for T lymphocyte homeostasis.

  17. Meta-analysis of genome-wide association studies discovers multiple loci for chronic lymphocytic leukemia

    NARCIS (Netherlands)

    Berndt, Sonja I; Camp, Nicola J; Skibola, Christine F; Vijai, Joseph; Wang, Zhaoming; Gu, Jian; Nieters, Alexandra; Kelly, Rachel S; Smedby, Karin E; Monnereau, Alain; Cozen, Wendy; Cox, Angela; Wang, Sophia S; Lan, Qing; Teras, Lauren R; Machado, Moara; Yeager, Meredith; Brooks-Wilson, Angela R; Hartge, Patricia; Purdue, Mark P; Birmann, Brenda M; Vajdic, Claire M; Cocco, Pierluigi; Zhang, Yawei; Giles, Graham G; Zeleniuch-Jacquotte, Anne; Lawrence, Charles; Montalvan, Rebecca; Burdett, Laurie; Hutchinson, Amy; Ye, Yuanqing; Call, Timothy G; Shanafelt, Tait D; Novak, Anne J; Kay, Neil E; Liebow, Mark; Cunningham, Julie M; Allmer, Cristine; Hjalgrim, Henrik; Adami, Hans-Olov; Melbye, Mads; Glimelius, Bengt; Chang, Ellen T; Glenn, Martha; Curtin, Karen; Cannon-Albright, Lisa A; Diver, W Ryan; Link, Brian K; Weiner, George J; Conde, Lucia; Bracci, Paige M; Riby, Jacques; Arnett, Donna K; Zhi, Degui; Leach, Justin M; Holly, Elizabeth A; Jackson, Rebecca D; Tinker, Lesley F; Benavente, Yolanda; Sala, Núria; Casabonne, Delphine; Becker, Nikolaus; Boffetta, Paolo; Brennan, Paul; Foretova, Lenka; Maynadie, Marc; McKay, James; Staines, Anthony; Chaffee, Kari G; Achenbach, Sara J; Vachon, Celine M; Goldin, Lynn R; Strom, Sara S; Leis, Jose F; Weinberg, J Brice; Caporaso, Neil E; Norman, Aaron D; De Roos, Anneclaire J; Morton, Lindsay M; Severson, Richard K; Riboli, Elio; Vineis, Paolo; Kaaks, Rudolph; Masala, Giovanna; Weiderpass, Elisabete; Chirlaque, María-Dolores; Vermeulen, Roel C H|info:eu-repo/dai/nl/216532620; Travis, Ruth C; Southey, Melissa C; Milne, Roger L; Albanes, Demetrius; Virtamo, Jarmo; Weinstein, Stephanie; Clavel, Jacqueline; Zheng, Tongzhang; Holford, Theodore R; Villano, Danylo J; Maria, Ann; Spinelli, John J; Gascoyne, Randy D; Connors, Joseph M; Bertrand, Kimberly A; Giovannucci, Edward; Kraft, Peter; Kricker, Anne; Turner, Jenny; Ennas, Maria Grazia; Ferri, Giovanni M; Miligi, Lucia; Liang, Liming; Ma, Baoshan; Huang, Jinyan; Crouch, Simon; Park, Ju-Hyun; Chatterjee, Nilanjan; North, Kari E; Snowden, John A; Wright, Josh; Fraumeni, Joseph F; Offit, Kenneth; Wu, Xifeng; de Sanjose, Silvia; Cerhan, James R; Chanock, Stephen J; Rothman, Nathaniel; Slager, Susan L

    2016-01-01

    Chronic lymphocytic leukemia (CLL) is a common lymphoid malignancy with strong heritability. To further understand the genetic susceptibility for CLL and identify common loci associated with risk, we conducted a meta-analysis of four genome-wide association studies (GWAS) composed of 3,100 cases and

  18. Catfish thrombocytes express an integrin-like CD41/CD61 complex.

    Science.gov (United States)

    Passer, B J; Chen, C H; Miller, N W; Cooper, M D

    1997-08-01

    A thrombocyte-specific antigen was identified in two closely related catfish, Ictalurus punctatus and Ictalurus furcatus, by monoclonal antibodies 4-20 and 7-2. The antibodies immunoprecipitate two noncovalently associated glycoprotein chains of Mr 180,000 and Mr 95,000. Under reducing conditions the Mr 180,000 chain is resolved into Mr 150,000 and 32,000 subcomponents. Analysis of N-terminal amino acid sequences indicates homology of the Mr 95,000 chain with the beta3 integrin subunit and homology of the Mr 150,000 chain with the alphaIIb integrin subunit. These antibodies induce catfish thrombocyte aggregation and alteration of cell shape. The data indicate conservation of the megakaryocyte/platelet-restricted CD41/CD61 complex in bony fish.

  19. The CD157-Integrin Partnership Controls Transendothelial Migration and Adhesion of Human Monocytes*

    Science.gov (United States)

    Lo Buono, Nicola; Parrotta, Rossella; Morone, Simona; Bovino, Paola; Nacci, Giulia; Ortolan, Erika; Horenstein, Alberto L.; Inzhutova, Alona; Ferrero, Enza; Funaro, Ada

    2011-01-01

    CD157, a member of the CD38 gene family, is an NAD-metabolizing ectoenzyme and a signaling molecule whose role in polarization, migration, and diapedesis of human granulocytes has been documented; however, the molecular events underpinning this role remain to be elucidated. This study focused on the role exerted by CD157 in monocyte migration across the endothelial lining and adhesion to extracellular matrix proteins. The results demonstrated that anti-CD157 antibodies block monocyte transmigration and adhesion to fibronectin and fibrinogen but that CD157 cross-linking is sufficient to overcome the block, suggesting an active signaling role for the molecule. Consistent with this is the observation that CD157 is prevalently located within the detergent-resistant membrane microdomains to which, upon clustering, it promotes the recruitment of β1 and β2 integrin, which, in turn, leads to the formation of a multimolecular complex favoring signal transduction. This functional cross-talk with integrins allows CD157 to act as a receptor despite its intrinsic structural inability to do so on its own. Intracellular signals mediated by CD157 rely on the integrin/Src/FAK (focal adhesion kinase) pathway, resulting in increased activity of the MAPK/ERK1/2 and the PI3K/Akt downstream signaling pathways, which are crucial in the control of monocyte transendothelial migration. Collectively, these findings indicate that CD157 acts as a molecular organizer of signaling-competent membrane microdomains and that it forms part of a larger molecular machine ruled by integrins. The CD157-integrin partnership provides optimal adhesion and transmigration of human monocytes. PMID:21478153

  20. Inhibition of human peripheral blood lymphocyte function by protoporphyrin and longwave ultraviolet light

    International Nuclear Information System (INIS)

    Barrett, K.E.; Yen, A.; Montisano, D.; Gigli, I.; Bigby, T.D.

    1994-01-01

    Modulation of immunologic effector cells by exogenous photoactive substances has been advanced as an underlying mechanism for the efficacy of various photochemotherapeutic regimens. It is also possible that endogenous photosensitizers, such as protoporphyrin, could similarly modify the function of immune cell types. The authors examined the effects of protoporphyrin plus longwave UV light on the ability of human PBL to proliferate in response to mitogens. Noncytotoxic dosages of protoporphyrin plus UV light suppressed PHA-stimulated proliferation of both PBMC and enriched T cells. CD8 + cells were more sensitive to this inhibitory effect than CD4 + cells. The inhibitory effect was also observed when proliferation was induced by the combination of a phorbol ester and ionomycin. Inhibition of PBMC proliferation was associated with inhibition of IL-2 secretion but proliferation was not restored with exogenous IL-2. Instead, the effect of protoporphyrin plus UV light may be on IL-2R. Cells treated with protoporphyrin and UV light did not display the increase in CD25 and β-chain of the IL-2R induced by PHA in control cells. In contrast to the effects of protoporphyrin and UV light on IL-2 and IL-2R α-chain protein expression, the accumulation of mRNA for these proteins induced by PHA was unaffected. None of the effects of protoporphyrin plus UV light on lymphocytes were observed in control experiments where cells were treated with either protoporphyrin or UV light alone. They conclude that biologically relevant dosages of protoporphyrin and UV light modify the function of circulating lymphocytes. 26 refs., 8 figs., 1 tab

  1. Targeted inhibition of αvβ3 integrin with an RNA aptamer impairs endothelial cell growth and survival

    International Nuclear Information System (INIS)

    Mi Jing; Zhang Xiuwu; Giangrande, Paloma H.; McNamara, James O.; Nimjee, Shahid M.; Sarraf-Yazdi, Shiva; Sullenger, Bruce A.; Clary, Bryan M.

    2005-01-01

    αvβ3 integrin is a crucial factor involved in a variety of physiological processes, such as cell growth and migration, tumor invasion and metastasis, angiogenesis, and wound healing. αvβ3 integrin exerts its effect by regulating endothelial cell (EC) migration, proliferation, and survival. Inhibiting the function of αvβ3 integrin, therefore, represents a potential anti-cancer, anti-thrombotic, and anti-inflammatory strategy. In this study, we tested an RNA aptamer, Apt-αvβ3 that binds recombinant αvβ3 integrin, for its ability to bind endogenous αvβ3 integrin on the surface of cells in culture and to subsequently affect cellular response. Our data illustrate that Apt-αvβ3 binds αvβ3 integrin expressed on the surface of live HUVECs. This interaction significantly decreases both basal and PDGF-induced cell proliferation as well as inhibition of cell adhesion. Apt-αvβ3 can also reduce PDGF-stimulated tube formation and increase HUVEC apoptosis through inhibition of FAK phosphorylation pathway. Our results demonstrate that by binding to its target, Apt-αvβ3 can efficiently inhibit human EC proliferation and survival, resulting in reduced angiogenesis. It predicts that Apt-αvβ3 could become useful in both tumor imaging and the treatment of tumor growth, atherosclerosis, thrombosis, and inflammation

  2. Down-regulation of integrin β1 and focal adhesion kinase in renal glomeruli under various hemodynamic conditions.

    Directory of Open Access Journals (Sweden)

    Xiaoli Yuan

    Full Text Available Given that integrin β1 is an important component of the connection to maintain glomerular structural integrity, by binding with multiple extracellular matrix proteins and mediating intracellular signaling. Focal adhesion kinase (FAK is the most essential intracellular integrator in the integrin β1-FAK signalling pathway. Here, we investigated the changes of the two molecules and visualized the possible interaction between them under various hemodynamic conditions in podocytes. Mice kidney tissues were prepared using in vivo cryotechnique (IVCT and then were stained and observed using light microscopy, confocal laser scanning microscopy and immunoelectron microscopy. The expression of these molecules were examined by western blot. Under the normal condition, integrin β1 stained continually and evenly at the membrane, and FAK was located in the cytoplasm and nuclei of the podocytes. There were significant colocalized plaques of two molecules. But under acute hypertensive and cardiac arrest conditions, integrin β1 decreased and stained intermittently. Similarly, FAK decreased and appeared uneven. Additionally, FAK translocated to the nuclei of the podocytes. As a result, the colocalization of integrin β1 and FAK reduced obviously under these conditions. Western blot assay showed a consistent result with the immunostaining. Collectively, the abnormal redistribution and decreased expressions of integrin β1 and FAK are important molecular events in regulating the functions of podocytes under abnormal hemodynamic conditions. IVCT could offer considerable advantages for morphological analysis when researching renal diseases.

  3. Quantitative gene-expression of the tumor angiogenesis markers vascular endothelial growth factor, integrin alphaV and integrin beta3 in human neuroendocrine tumors

    DEFF Research Database (Denmark)

    Oxboel, Jytte; Binderup, Tina; Knigge, Ulrich

    2009-01-01

    , in neuroendocrine tumors. We used quantitative real-time PCR for measuring mRNA gene-expression of vascular endothelial growth factor (VEGF), integrin alphaV, and integrin beta3, and CD34 for a group of patients with neuroendocrine tumors (n=13). Tissue from patients with colorectal cancer liver metastases (n=14...... compared to both colorectal liver metastases (p=0.10) and normal liver tissue (p=0.06). In neuroendocrine tumors, gene-expression was highly variable of VEGF (530-fold), integrin alphaV (23-fold) and integrin beta3 (106-fold). Quantitative gene-expression levels of the key angiogenesis molecules VEGF......Anti-angiogenesis treatment is a promising new therapy for cancer that recently has also been suggested for patients with neuroendocrine tumors. The aim of the present study was therefore to investigate the level of tumor angiogenesis, and thereby the molecular basis for anti-angiogenesis treatment...

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

    International Nuclear Information System (INIS)

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

    1992-01-01

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

  5. RPTP-alpha acts as a transducer of mechanical force on alphav/beta3-integrin-cytoskeleton linkages

    DEFF Research Database (Denmark)

    von Wichert, Gotz; Jiang, Guoying; Kostic, Ana

    2003-01-01

    Cell motility on ECM critically depends on the cellular response to force from the matrix. We find that force-dependent reinforcement of alphav/beta3-integrin-mediated cell-matrix connections requires the receptor-like tyrosine phosphatase alpha (RPTPalpha). RPTPalpha colocalizes with alphav...... of alphav/beta3-integrin-cytoskeleton connections during the initial phase of ECM contact. These observations indicate that Src family kinases have distinct functions during adhesion site assembly, and that RPTPalpha is an early component in force-dependent signal transduction pathways leading...

  6. Targeting ILK and β4 integrin abrogates the invasive potential of ovarian cancer

    International Nuclear Information System (INIS)

    Choi, Yoon Pyo; Kim, Baek Gil; Gao, Ming-Qing; Kang, Suki; Cho, Nam Hoon

    2012-01-01

    Highlights: ► The potential of targeting ILK and integrins for highly aggressive ovarian cancer. ► Unanticipated synergistic effect for the combination of ILK/β4 integrin. ► Combination of ILK/β4 integrin effectively inhibited the PI3K/Akt/Rac1 cascade. ► Targeting of β4 integrin/ILK had potent inhibitory effects in ovarian cancer. -- Abstract: Integrins and integrin-linked kinase (ILK) are essential to cancerous invasion because they mediate physical interactions with the extracellular matrix, and regulate oncogenic signaling pathways. The purpose of our study is to determine whether deletion of β1 and β4 integrin and ILK, alone or in combination, has antitumoral effects in ovarian cancer. Expression of β1 and β4 integrin and ILK was analyzed by immunohistochemistry in 196 ovarian cancer tissue samples. We assessed the effects of depleting these molecules with shRNAs in ovarian cancer cells by Western blot, conventional RT-PCR, cell proliferation, migration, invasion, and in vitro Rac1 activity assays, and in vivo xenograft formation assays. Overexpression of β4 integrin and ILK in human ovarian cancer specimens was found to correlate with tumor aggressiveness. Depletion of these targets efficiently suppresses ovarian cancer cell proliferation, migration, and invasion in vitro and xenograft tumor formation in vivo. We also demonstrated that single depletion of ILK or combination depletion of β4 integrin/ILK inhibits phosphorylation of downstream signaling targets, p-Ser 473 Akt and p-Thr202/Tyr204 Erk1/2, and activation of Rac1, as well as reduce expression of MMP-2 and MMP-9 and increase expression of caspase-3 in vitro. In conclusion, targeting β4 integrin combined with ILK can instigate the latent tumorigenic potential and abrogate the invasive potential in ovarian cancer.

  7. Targeting ILK and {beta}4 integrin abrogates the invasive potential of ovarian cancer

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Yoon Pyo; Kim, Baek Gil [BK21 Project for Medical Science, Yonsei University College of Medicine, Seoul (Korea, Republic of); Department of Pathology, Yonsei University College of Medicine, Seoul (Korea, Republic of); Gao, Ming-Qing; Kang, Suki [Department of Pathology, Yonsei University College of Medicine, Seoul (Korea, Republic of); Cho, Nam Hoon, E-mail: cho1988@yuhs.ac [BK21 Project for Medical Science, Yonsei University College of Medicine, Seoul (Korea, Republic of); Department of Pathology, Yonsei University College of Medicine, Seoul (Korea, Republic of)

    2012-10-26

    Highlights: Black-Right-Pointing-Pointer The potential of targeting ILK and integrins for highly aggressive ovarian cancer. Black-Right-Pointing-Pointer Unanticipated synergistic effect for the combination of ILK/{beta}4 integrin. Black-Right-Pointing-Pointer Combination of ILK/{beta}4 integrin effectively inhibited the PI3K/Akt/Rac1 cascade. Black-Right-Pointing-Pointer Targeting of {beta}4 integrin/ILK had potent inhibitory effects in ovarian cancer. -- Abstract: Integrins and integrin-linked kinase (ILK) are essential to cancerous invasion because they mediate physical interactions with the extracellular matrix, and regulate oncogenic signaling pathways. The purpose of our study is to determine whether deletion of {beta}1 and {beta}4 integrin and ILK, alone or in combination, has antitumoral effects in ovarian cancer. Expression of {beta}1 and {beta}4 integrin and ILK was analyzed by immunohistochemistry in 196 ovarian cancer tissue samples. We assessed the effects of depleting these molecules with shRNAs in ovarian cancer cells by Western blot, conventional RT-PCR, cell proliferation, migration, invasion, and in vitro Rac1 activity assays, and in vivo xenograft formation assays. Overexpression of {beta}4 integrin and ILK in human ovarian cancer specimens was found to correlate with tumor aggressiveness. Depletion of these targets efficiently suppresses ovarian cancer cell proliferation, migration, and invasion in vitro and xenograft tumor formation in vivo. We also demonstrated that single depletion of ILK or combination depletion of {beta}4 integrin/ILK inhibits phosphorylation of downstream signaling targets, p-Ser 473 Akt and p-Thr202/Tyr204 Erk1/2, and activation of Rac1, as well as reduce expression of MMP-2 and MMP-9 and increase expression of caspase-3 in vitro. In conclusion, targeting {beta}4 integrin combined with ILK can instigate the latent tumorigenic potential and abrogate the invasive potential in ovarian cancer.

  8. Whole blood microculture assay of human lymphocyte function.

    Science.gov (United States)

    Pauly, J L; Han, T

    1976-11-01

    A whole blood microculture assay is described for measuring lymphocyte reactivity to mitogenic and antigenic stimulants. This assay employs heparinized whole blood, serum-free culture medium, microtiter plates, and a Multiple Automated Sample Harvester (MASH). When this assay is compared to other leukocyte assays, its major advantages include (1) the utilization of fewer lymphocytes per microculture, thuus reducing the amount of blood required per test while increasing the number of test agents and replicate cultures which can be employed in any given experiment; (2) the conservation of mitogens, antigens, drugs, enzymes, hormones, lymphokines, and other test agents, some of which are either expensive of difficult to prepare in large quantities; (3) the elimination of lymphocyte isolation and purification procedures which may disrupt the relative proportion of T cells, B cells and antigen-processing cells; and (4) the application of an automated harvester which simplifies and expedites procedures required for processing cells for liquid scintillation counting.

  9. Depression of T lymphocyte function in chimpanzees receiving thymectomy and irradiation

    International Nuclear Information System (INIS)

    Gilbertsen, R.B.; Metzgar, R.S.

    1978-01-01

    In studies analogous to those in which the thymus dependency of immune functions in murine systems was determined, three chimpanzees were thymectomized, splenectomized, exposed to lethal doses of whole body x-irradiation with limited bone marrow shielding, and subsequently evaluated for lymphocyte markers and functions over a period of years. In the oldest animal studied (Irena, 7.2 years at surgery), the percentage of peripheral blood T cells decreased to about 60% of control values and remained at that level for approximately 1 1 / 2 years before returning to normal. In the two youngest chimpanzees T cell rosette values dropped to 15 to 40% of control values after irradiation. T cell percentages in one of these young chimpanzees returned to about 75% of the controls 2 1 / 2 years after x-irradiation. Phytohemagglutinin and concanavalin A mitogen responses were less affected in the oldest chimpanzee. However, even in the oldest animal, the responses to phytohemagglutinin and concanavalin A began to show a gradual and consistent decline 1 1 / 2 years after irradiation. Mixed leukocyte culture responsiveness was most affected by the experimental procedures, being greatly reduced in all three chimpanzees during varying time intervals. In general, the effects of the experimental procedures used to produce T cell deficiencies varied with the age of the chimpanzee at surgery, the time after irradiation when the animal was tested, and the lymphocyte marker or function studied

  10. SNARE-mediated trafficking of α5β1 integrin is required for spreading in CHO cells

    International Nuclear Information System (INIS)

    Skalski, Michael; Coppolino, Marc G.

    2005-01-01

    In this study, the role of SNARE-mediated membrane traffic in regulating integrin localization was examined and the requirement for SNARE function in cellular spreading was quantitatively assessed. Membrane traffic was inhibited with the VAMP-specific catalytic light chain from tetanus toxin (TeTx-LC), a dominant-negative form (E329Q) of N-ethylmaleimide-sensitive fusion protein (NSF), and brefeldin A (BfA). Inhibition of membrane traffic with either E329Q-NSF or TeTx-LC, but not BfA, significantly inhibited spreading of CHO cells on fibronectin. Spreading was rescued in TeTx-LC-expressing cells by co-transfection with a TeTx-resistant cellubrevin/VAMP3. E329Q-NSF, a general inhibitor of SNARE function, was a more potent inhibitor of cell spreading than TeTx-LC, suggesting that tetanus toxin-insensitive SNAREs contribute to adhesion. It was found that E329Q-NSF prevented trafficking of α 5 β 1 integrins from a central Rab11-containing compartment to sites of protrusion during cell adhesion, while TeTx-LC delayed this trafficking. These results are consistent with a model of cellular adhesion that implicates SNARE function as an important component of integrin trafficking during the process of cell spreading

  11. The role of mechanical force and ROS in integrin-dependent signals.

    Directory of Open Access Journals (Sweden)

    Kathrin S Zeller

    Full Text Available Cells are exposed to several types of integrin stimuli, which generate responses generally referred to as "integrin signals", but the specific responses to different integrin stimuli are poorly defined. In this study, signals induced by integrin ligation during cell attachment, mechanical force from intracellular contraction, or cell stretching by external force were compared. The elevated phosphorylation levels of several proteins during the early phase of cell attachment and spreading of fibroblast cell lines were not affected by inhibition of ROCK and myosin II activity, i.e. the reactions occurred independently of intracellular contractile force acting on the adhesion sites. The contraction-independent phosphorylation sites included ERK1/2 T202/Y204, AKT S473, p130CAS Y410, and cofilin S3. In contrast to cell attachment, cyclic stretching of the adherent cells induced a robust phosphorylation only of ERK1/2 and the phosphorylation levels of the other investigated proteins were not or only moderately affected by stretching. No major differences between signaling via α5β1 or αvβ3 integrins were detected. The importance of mitochondrial ROS for the integrin-induced signaling pathways was investigated using rotenone, a specific inhibitor of complex I in the respiratory chain. While rotenone only moderately reduced ATP levels and hardly affected the signals induced by cyclic cell stretching, it abolished the activation of AKT and reduced the actin polymerization rate in response to attachment in both cell lines. In contrast, scavenging of extracellular ROS with catalase or the vitamin C analog Asc-2P did not significantly influence the attachment-derived signaling, but caused a selective and pronounced enhancement of ERK1/2 phosphorylation in response to stretching. In conclusion, the results showed that "integrin signals" are composed of separate sets of reactions triggered by different types of integrin stimulation. Mitochondrial ROS and

  12. Multifaced Roles of the αvβ3 Integrin in Ehlers–Danlos and Arterial Tortuosity Syndromes’ Dermal Fibroblasts

    Directory of Open Access Journals (Sweden)

    Nicoletta Zoppi

    2018-03-01

    Full Text Available The αvβ3 integrin, an endothelial cells’ receptor-binding fibronectin (FN in the extracellular matrix (ECM of blood vessels, regulates ECM remodeling during migration, invasion, angiogenesis, wound healing and inflammation, and is also involved in the epithelial mesenchymal transition. In vitro-grown human control fibroblasts organize a fibrillar network of FN, which is preferentially bound on the entire cell surface to its canonical α5β1 integrin receptor, whereas the αvβ3 integrin is present only in rare patches in focal contacts. We report on the preferential recruitment of the αvβ3 integrin, due to the lack of FN–ECM and its canonical integrin receptor, in dermal fibroblasts from Ehlers–Danlos syndromes (EDS and arterial tortuosity syndrome (ATS, which are rare multisystem connective tissue disorders. We review our previous findings that unraveled different biological mechanisms elicited by the αvβ3 integrin in fibroblasts derived from patients affected with classical (cEDS, vascular (vEDS, hypermobile EDS (hEDS, hypermobility spectrum disorders (HSD, and ATS. In cEDS and vEDS, respectively, due to defective type V and type III collagens, αvβ3 rescues patients’ fibroblasts from anoikis through a paxillin-p60Src-mediated cross-talk with the EGF receptor. In hEDS and HSD, without a defined molecular basis, the αvβ3 integrin transduces to the ILK-Snail1-axis inducing a fibroblast-to-myofibroblast-transition. In ATS cells, the deficiency of the dehydroascorbic acid transporter GLUT10 leads to redox imbalance, ECM disarray together with the activation of a non-canonical αvβ3 integrin-TGFBRII signaling, involving p125FAK/p60Src/p38MAPK. The characterization of these different biological functions triggered by αvβ3 provides insights into the multifaced nature of this integrin, at least in cultured dermal fibroblasts, offering future perspectives for research in this field.

  13. Selective Modulation of Integrin-mediated Cell Migration by Distinct ADAM Family MembersV⃞

    Science.gov (United States)

    Huang, Jing; Bridges, Lance C.; White, Judith M.

    2005-01-01

    A disintegrin and a metalloprotease (ADAM) family members have been implicated in many biological processes. Although it is recognized that recombinant ADAM disintegrin domains can interact with integrins, little is known about ADAM-integrin interactions in cellular context. Here, we tested whether ADAMs can selectively regulate integrin-mediated cell migration. ADAMs were expressed in Chinese hamster ovary cells that express defined integrins (α4β1, α5β1, or both), and cell migration on full-length fibronectin or on its α4β1 or α5β1 binding fragments was studied. We found that ADAMs inhibit integrin-mediated cell migration in patterns dictated by the integrin binding profiles of their isolated disintegrin domains. ADAM12 inhibited cell migration mediated by the α4β1 but not the α5β1 integrin. ADAM17 had the reciprocal effect; it inhibited α5β1- but not α4β1-mediated cell migration. ADAM19 and ADAM33 inhibited migration mediated by both α4β1 and α5β1 integrins. A point mutation in the ADAM12 disintegrin loop partially reduced the inhibitory effect of ADAM12 on cell migration on the α4β1 binding fragment of fibronectin, whereas mutations that block metalloprotease activity had no effect. Our results indicate that distinct ADAMs can modulate cell migration mediated by specific integrins in a pattern dictated, at least in part, by their disintegrin domains. PMID:16079176

  14. Integrin α6Bβ4 inhibits colon cancer cell proliferation and c-Myc activity

    International Nuclear Information System (INIS)

    Dydensborg, Anders Bondo; Teller, Inga C; Groulx, Jean-François; Basora, Nuria; Paré, Fréderic; Herring, Elizabeth; Gauthier, Rémy; Jean, Dominique; Beaulieu, Jean-François

    2009-01-01

    Integrins are known to be important contributors to cancer progression. We have previously shown that the integrin β4 subunit is up-regulated in primary colon cancer. Its partner, the integrin α6 subunit, exists as two different mRNA splice variants, α6A and α6B, that differ in their cytoplasmic domains but evidence for distinct biological functions of these α6 splice variants is still lacking. In this work, we first analyzed the expression of integrin α6A and α6B at the protein and transcript levels in normal human colonic cells as well as colorectal adenocarcinoma cells from both primary tumors and established cell lines. Then, using forced expression experiments, we investigated the effect of α6A and α6B on the regulation of cell proliferation in a colon cancer cell line. Using variant-specific antibodies, we observed that α6A and α6B are differentially expressed both within the normal adult colonic epithelium and between normal and diseased colonic tissues. Proliferative cells located in the lower half of the glands were found to predominantly express α6A, while the differentiated and quiescent colonocytes in the upper half of the glands and surface epithelium expressed α6B. A relative decrease of α6B expression was also identified in primary colon tumors and adenocarcinoma cell lines suggesting that the α6A/α6B ratios may be linked to the proliferative status of colonic cells. Additional studies in colon cancer cells showed that experimentally restoring the α6A/α6B balance in favor of α6B caused a decrease in cellular S-phase entry and repressed the activity of c-Myc. The findings that the α6Bβ4 integrin is expressed in quiescent normal colonic cells and is significantly down-regulated in colon cancer cells relative to its α6Aβ4 counterpart are consistent with the anti-proliferative influence and inhibitory effect on c-Myc activity identified for this α6Bβ4 integrin. Taken together, these findings point out the importance of integrin

  15. The membrane-cytoplasm interface of integrin alpha subunits is critical for receptor latency.

    OpenAIRE

    Briesewitz, R; Kern, A; Smilenov, L B; David, F S; Marcantonio, E E

    1996-01-01

    Localization of integrin receptors to focal contact sites occurs upon ligand binding. This activity is latent, since unoccupied integrin receptors do not localize to focal contacts. Deletion analysis has revealed that the alpha cytoplasmic domains is required for the maintenance of integrin receptor latency. Our current hypothesis for the mechanism of integrin post-ligand binding events is that there is a change in relationship of alpha and beta cytoplasmic domains, which overcomes receptor l...

  16. Fas expression on peripheral blood lymphocytes in systemic lupus erythematosus (SLE) : relation to lymphocyte activation and disease activity

    NARCIS (Netherlands)

    Bijl, M; Horst, G; Limburg, PC; Kallenberg, CGM

    2001-01-01

    Levels of apoptotic lymphocytes have been found to be increased in SLE and persistence of apoptotic cells has been associated with autoantibody production, Increased lymphocyte Fas (CD95) expression due to lymphocyte activation may account for increased Susceptibility to Fas-mediated apoptosis in

  17. Expression Profile of the Integrin Receptor Subunits in the Guinea Pig Sclera.

    Science.gov (United States)

    Wang, Kevin K; Metlapally, Ravikanth; Wildsoet, Christine F

    2017-06-01

    The ocular dimensional changes in myopia reflect increased scleral remodeling, and in high myopia, loss of scleral integrity leads to biomechanical weakening and continued scleral creep. As integrins, a type of cell surface receptors, have been linked to scleral remodeling, they represent potential targets for myopia therapies. As a first step, this study aimed to characterize the integrin subunits at the messenger RNA level in the sclera of the guinea pig, a more recently added but increasingly used animal model for myopia research. Primers for α and β integrin subunits were designed using NCBI/UCSC Genome Browser and Primer3 software tools. Total RNA was extracted from normal scleral tissue and isolated cultured scleral fibroblasts, as well as liver and lung, as reference tissues, all from guinea pig. cDNA was produced by reverse transcription, PCR was used to amplify products of predetermined sizes, and products were sequenced using standard methods. Guinea pig scleral tissue expressed all known integrin alpha subunits except αD and αE. The latter integrin subunits were also not expressed by cultured guinea pig scleral fibroblasts; however, their expression was confirmed in guinea pig liver. In addition, isolated cultured fibroblasts did not express integrin subunits αL, αM, and αX. This difference between results for cultured cells and intact sclera presumably reflects the presence in the latter of additional cell types. Both guinea pig scleral tissue and isolated scleral fibroblasts expressed all known integrin beta subunits. All results were verified through sequencing. The possible contributions of integrins to scleral remodeling make them plausible targets for myopia prevention. Data from this study will help guide future ex vivo and in vitro studies directed at understanding the relationship between scleral integrins and ocular growth regulation in the guinea pig model for myopia.

  18. The therapeutic potential of I-domain integrins.

    Science.gov (United States)

    Brennan, Marian; Cox, Dermot

    2014-01-01

    Due to their role in processes central to cancer and autoimmune disease I-domain integrins are an attractive drug target. Both antibodies and small molecule antagonists have been discovered and tested in the clinic. Much of the effort has focused on αLβ2 antagonists. Maybe the most successful was the monoclonal antibody efalizumab, which was approved for the treatment of psoriasis but subsequently withdrawn from the market due to the occurrence of a serious adverse effect (progressive multifocal leukoencephalopathy). Other monoclonal antibodies were tested for the treatment of reperfusion injury, post-myocardial infarction, but failed to progress due to lack of efficacy. New potent small molecule inhibitors of αv integrins are promising reagents for treating fibrotic disease. Small molecule inhibitors targeting collagen-binding integrins have been discovered and future work will focus on identifying molecules selectively targeting each of the collagen receptors and identifying appropriate target diseases for future clinical studies.

  19. Immuno phenotype of blood lymphocytes in radiation-associated Hodgkin's disease

    International Nuclear Information System (INIS)

    Butenko, A.K.

    2000-01-01

    Immuno phenotype of peripheral blood lymphocytes has been studied in Hodgkin's disease including patients exposed to radionuclides of the characteristic Chernobyl pattern. The group of patients under study has been characterized by decreasing T- and NK-cell immunity, such a decrease being more pronounced in radiation-associated Hodgkin's lymphoma. The data obtained as well as the evidence of Epstein-Barr virus activation could explain the aggressiveness of the disease in such patients and the difficulties in their treatment

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

    OpenAIRE

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

    2012-01-01

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

  1. Alteration of Lymphocyte Phenotype and Function in Sickle Cell Anemia: Implications for Vaccine Responses

    Science.gov (United States)

    Balandya, Emmanuel; Reynolds, Teri; Obaro, Stephen; Makani, Julie

    2016-01-01

    Individuals with sickle cell anemia (SCA) have increased susceptibility to infections, secondary to impairment of immune function. Besides the described dysfunction in innate immunity, including impaired opsonization and phagocytosis of bacteria, evidence of dysfunction of T and B lymphocytes in SCA has also been reported. This includes reduction in the proportion of circulating CD4+ and CD8+ T cells, reduction of CD4+ helper : CD8+ suppressor T cell ratio, aberrant activation and dysfunction of regulatory T cells (Treg), skewing of CD4+ T cells towards Th2 response and loss of IgM-secreting CD27+IgMhighIgDlow memory B cells. These changes occur on the background of immune activation characterized by predominance of memory CD4+ T cell phenotypes, increased Th17 signaling and elevated levels of C-reactive protein and pro-inflammatory cytokines IL-6 and TNF-α, which may affect the immunogenicity and protective efficacy of vaccines available to prevent infections in SCA. Thus, in order to optimize the use of vaccines in SCA, a thorough understanding of T and B lymphocyte functions and vaccine reactivity among individuals with SCA is needed. Studies should be encouraged of different SCA populations, including sub-Saharan Africa where the burden of SCA is highest. This article summarizes our current understanding of lymphocyte biology in SCA, and highlights areas that warrant future research. PMID:27237467

  2. Visualization of integrin Mac-1 in vivo.

    Science.gov (United States)

    Lim, Kihong; Hyun, Young-Min; Lambert-Emo, Kris; Topham, David J; Kim, Minsoo

    2015-11-01

    β2 integrins play critical roles in migration of immune cells and in the interaction with other cells, pathogens, and the extracellular matrix. Among the β2 integrins, Mac-1 (Macrophage antigen-1), composed of CD11b and CD18, is mainly expressed in innate immune cells and plays a major role in cell migration and trafficking. In order to image Mac-1-expressing cells both in live cells and mouse, we generated a knock-in (KI) mouse strain expressing CD11b conjugated with monomeric yellow fluorescent protein (mYFP). Expression of CD11b-mYFP protein was confirmed by Western blot and silver staining of CD11b-immunoprecipitates and total cell lysates from the mouse splenocytes. Mac-1-mediated functions of the KI neutrophils were comparable with those in WT cells. The fluorescence intensity of CD11b-mYFP was sufficient to image CD11b expressing cells in live mice using intravital two-photon microscopy. In vitro, dynamic changes in the intracellular localization of CD11b molecules could be measured by epifluorescent microscopy. Finally, CD11b-expressing immune cells from tissue were easily detected by flow cytometry without anti-CD11b antibody staining. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Cellular Interaction of Integrin α3β1 with Laminin 5 Promotes Gap Junctional Communication

    Science.gov (United States)

    Lampe, Paul D.; Nguyen, Beth P.; Gil, Susana; Usui, Marcia; Olerud, John; Takada, Yoshikazu; Carter, William G.

    1998-01-01

    Wounding of skin activates epidermal cell migration over exposed dermal collagen and fibronectin and over laminin 5 secreted into the provisional basement membrane. Gap junctional intercellular communication (GJIC) has been proposed to integrate the individual motile cells into a synchronized colony. We found that outgrowths of human keratinocytes in wounds or epibole cultures display parallel changes in the expression of laminin 5, integrin α3β1, E-cadherin, and the gap junctional protein connexin 43. Adhesion of keratinocytes on laminin 5, collagen, and fibronectin was found to differentially regulate GJIC. When keratinocytes were adhered on laminin 5, both structural (assembly of connexin 43 in gap junctions) and functional (dye transfer) assays showed a two- to threefold increase compared with collagen and five- to eightfold over fibronectin. Based on studies with immobilized integrin antibody and integrin-transfected Chinese hamster ovary cells, the interaction of integrin α3β1 with laminin 5 was sufficient to promote GJIC. Mapping of intermediate steps in the pathway linking α3β1–laminin 5 interactions to GJIC indicated that protein trafficking and Rho signaling were both required. We suggest that adhesion of epithelial cells to laminin 5 in the basement membrane via α3β1 promotes GJIC that integrates individual cells into synchronized epiboles. PMID:9852164

  4. Scintigraphies after renal transplant: study of transplant function and of sup(99m)Tc labelled lymphocytes transit

    Energy Technology Data Exchange (ETDEWEB)

    Guey, A; Touraine, J L; Collard, M; Traeger, J [Institut National de la Sante et de la Recherche Medicale (INSERM), Hopital Edouard-Herriot, 69 - Lyon (France)

    1977-01-01

    In a first series of scintigraphic investigations in patients with a renal transplant, 'conventional' tracers, were used (sup(99m)Tc pertechnetate and sodium iodohippurate iodine-131) and they gave insight on alteration of the function of the transplanted kidney. Precisions on scintigraphic criteria of diagnosis of vascular complications and urinary fistulae were obtained but no clear cut discrimination between ischemic acute tubular necrosis and early rejection was apparent. Despite the use of a data acquisition and processing system (SCINTI-16) and despite improved functional characterization of the transplant, such methods do not appear to provide definite criteria for an early diagnosis of acute rejection. A different approach, using lymphocytes as a vector, was investigated. A method for lymphocyte labelling with sup(99m)Tc was developed. Labelled autologous lymphocytes were injected to normal volunteers and to patients, then the body distribution was determined and followed over a period of 24 hours. The activity was more precisely quantified at the site of the transplant, repeatedly for 24 hours following injection, and the resulting curves were altered in phases of preclinical rejection. The lymphocyte transit in the kidney would be slower during acute rejection crises of the transplanted kidney and this might be responsible for the different aspect of the curve, especially at 3 to 5 hours. This working hypothesis, will be analysed and documented, using more precise quantifications (close selection of the studied area), evaluating the intrarenal transit of each lymphocyte subpopulation and accurately measuring isotope release. It will then perhaps be possible to define very precise and precocious criteria of rejection.

  5. Integrins in cell migration – the actin connection

    OpenAIRE

    Vicente-Manzanares, Miguel; Choi, Colin Kiwon; Horwitz, Alan Rick

    2008-01-01

    The connection between integrins and actin is driving the field of cell migration in new directions. Integrins and actin are coupled through a physical linkage, which provides traction for migration. Recent studies show the importance of this linkage in regulating adhesion organization and development. Actin polymerization orchestrates adhesion assembly near the leading edge of a migrating cell, and the dynamic cross-linking of actin filaments promotes adhesion maturat...

  6. Breast Cancer Cells in Three-dimensional Culture Display an Enhanced Radioresponse after Coordinate Targeting of Integrin ?5?1 and Fibronectin

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Jin-Min; Onodera, Yasuhito; Bissell, Mina J; Park, Catherine C

    2010-04-07

    Tactics to selectively enhance cancer radioresponse are of great interest. Cancer cells actively elaborate and remodel their extracellular matrix (ECM) to aid in survival and progression. Previous work has shown that {beta}1-integrin inhibitory antibodies can enhance the growth-inhibitory and apoptotic responses of human breast cancer cell lines to ionizing radiation, either when cells are cultured in three-dimensional laminin-rich ECM (3D lrECM) or grown as xenografts in mice. Here, we show that a specific {alpha} heterodimer of {beta}1-integrin preferentially mediates a prosurvival signal in human breast cancer cells that can be specifically targeted for therapy. 3D lrECM culture conditions were used to compare {alpha}-integrin heterodimer expression in malignant and nonmalignant cell lines. Under these conditions, we found that expression of {alpha}5{beta}1-integrin was upregulated in malignant cells compared with nonmalignant breast cells. Similarly, we found that normal and oncofetal splice variants of fibronectin, the primary ECM ligand of {alpha}5{beta}1-integrin, were also strikingly upregulated in malignant cell lines compared with nonmalignant acini. Cell treatment with a peptide that disrupts the interactions of {alpha}5{beta}1-integrin with fibronectin promoted apoptosis in malignant cells and further heightened the apoptotic effects of radiation. In support of these results, an analysis of gene expression array data from breast cancer patients revealed an association of high levels of {alpha}5-integrin expression with decreased survival. Our findings offer preclinical validation of fibronectin and {alpha}5{beta}1-integrin as targets for breast cancer therapy.

  7. Alteration of lymphocyte functions by 8-methoxypsoralen and longwave ultraviolet radiation. I. Suppressive effects of PUVA on T-lymphocyte migration in vitro

    International Nuclear Information System (INIS)

    Okamoto, H.; Takigawa, M.; Horio, T.

    1985-01-01

    We investigated the influence of 8-methoxypsoralen (8-MOP) plus long-wave ultraviolet radiation (PUVA) on lymphocyte migration in vitro. Nylon wool-purified, mouse splenic T lymphocytes showed locomotive responses to casein, normal mouse serum (NMS), and zymosan-activated mouse serum (ZAS). Migratory responses to casein and NMS, and to ZAS were remarkably suppressed in lymphocytes exposed to 0.5 J/cm2 UVA plus 0.1 micrograms/ml 8-MOP and to 0.8 J/cm2 UVA plus 8-MOP, respectively. The PUVA treatment used in the present study had no effect on random movement and lymphocyte viability. T lymphocytes cultured in the absence of mitogenic agent for 24 h demonstrated a greater increase in their migration activity than noncultured cells, while lymphocytes cultured after 1.0 J/cm2 PUVA pretreatment remained low. These findings suggest that the therapeutic effect of PUVA on inflammatory skin disorders may be due in part to the suppression of lymphocyte migration

  8. Effects of lithium on the functions of human neutrophils and lymphocytes in vitro and in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, R.; Walters, L.; Grabow, G.; Van der Merwe, M.; Van Rensburg, C.E. (Pretoria Univ. (South Africa))

    1982-10-02

    The effects of lithium sulphate (LiSO/sub 4/) at concentrations ranging from 10/sup -7/M to 10/sup -2/M on human polymorphonuclear leucocyte (PMNL) and lymphocyte functions in vitro were investigated. The leucocyte functions assessed were PMNL motility, post-phagocytic hexose-monophosphate shunt activity, myeloperoxidase-mediated iodination of Candida albicans and lymphocyte transformation to mitogens. These same functions as well the results of serological studies were assessed in normal volunteers prior to ingestion of lithium carbonate (LiCO/sub 3/), 2 hours and 24 hours after the ingestion of a single oral dose of 480 mg LiCO/sub 3/ and on the 4th day of ingestion of 2x480 mg LiCO/sub 3/ tablets daily. Incubation of PMNL with LiSO/sub 4/ at concentrations up to 10/sup -3/M had no detectable effects on motility or post-phagocytic metabolic activity. Higher concentrations (10/sup -3/M) inhibited these functions. Likewise, at concentrations up to 1x10/sup -4/M LiSO/sub 4/ had no effects on mitogen-induced transformation of lymphocytes, although higher concentrations did inhibit this activity. These same leucocyte functions were unaffected by ingestion of LiCO/sub 3/. Levels of serum immunoglobulins and complement components, total haemolytic complement activity and salivary lgA values also remained unaltered. In vitro investigations showed that at a concentration of 10/sup -3/M LiSO/sub 4/ had no inhibitory effects on the stimulation of PMNL motility mediated by ascorbate, levamisole and thiamine.

  9. Activation of c-Raf-1 kinase signal transduction pathway in alpha(7) integrin-deficient mice.

    Science.gov (United States)

    Saher, G; Hildt, E

    1999-09-24

    Integrin alpha(7)-deficient mice develop a novel form of muscular dystrophy. Here we report that deficiency of alpha(7) integrin causes an activation of the c-Raf-1/mitogen-activated protein (MAP) 2 kinase signal transduction pathway in muscle cells. The observed activation of c-Raf-1/MAP2 kinases is a specific effect, because the alpha(7) integrin deficiency does not cause unspecific stress as determined by measurement of the Hsp72/73 level and activity of the JNK2 kinase. Because an increased level of activated FAK was found in muscle of alpha(7) integrin-deficient mice, the activation of c-Raf-1 kinase is triggered most likely by an integrin-dependent pathway. In accordance with this, in the integrin alpha(7)-deficient mice, part of the integrin beta(1D) variant in muscle is replaced by the beta(1A) variant, which permits the FAK activation. A recent report describes that integrin activity can be down-modulated by the c-Raf-1/MAP2 kinase pathway. Specific activation of the c-Raf-1/MAP2 kinases by cell-permeable peptides in skeletal muscle of rabbits causes degeneration of muscle fibers. Therefore, we conclude that in alpha(7) integrin-deficient mice, the continuous activation of c-Raf-1 kinase causes a permanent reduction of integrin activity diminishing integrin-dependent cell-matrix interactions and thereby contributing to the development of the dystrophic phenotype.

  10. Integrin αβ1, αvβ, α6β effectors p130Cas, Src and talin regulate carcinoma invasion and chemoresistance

    International Nuclear Information System (INIS)

    Sansing, Hope A.; Sarkeshik, Ali; Yates, John R.; Patel, Vyomesh; Gutkind, J. Silvio; Yamada, Kenneth M.; Berrier, Allison L.

    2011-01-01

    Research highlights: → Proteomics of clustered integrin αβ1, α v β, α 6 β receptors in oral carcinoma. → p130Cas, Dek, Src and talin regulate oral carcinoma invasion. → p130Cas, talin, Src and zyxin regulate oral carcinoma resistance to cisplatin. -- Abstract: Ligand engagement by integrins induces receptor clustering and formation of complexes at the integrin cytoplasmic face that controls cell signaling and cytoskeletal dynamics critical for adhesion-dependent processes. This study searches for a subset of integrin effectors that coordinates both tumor cell invasion and resistance to the chemotherapeutic drug cisplatin in oral carcinomas. Candidate integrin effectors were identified in a proteomics screen of proteins recruited to clustered integrin αβ1, α v β or α 6 β receptors in oral carcinomas. Proteins with diverse functions including microtubule and actin binding proteins, and factors involved in trafficking, transcription and translation were identified in oral carcinoma integrin complexes. Knockdown of effectors in the oral carcinoma HN12 cells revealed that p130Cas, Dek, Src and talin were required for invasion through Matrigel. Disruption of talin or p130Cas by RNA interference increased resistance to cisplatin, whereas targeting Dek, Src or zyxin reduced HN12 resistance to cisplatin. Analysis of the spreading of HN12 cells on collagen I and laminin I revealed that a decrease in p130Cas or talin expression inhibited spreading on both matrices. Interestingly, a reduction in zyxin expression enhanced spreading on laminin I and inhibited spreading on collagen I. Reduction of Dek, Src, talin or zyxin expression reduced HN12 proliferation by 30%. Proliferation was not affected by a reduction in p130Cas expression. We conclude that p130Cas, Src and talin function in both oral carcinoma invasion and resistance to cisplatin.

  11. Pathologic characteristics of gut-associated lymphoid tissues and lymphocyte apoptosis in mouse intestine after neutron-and γ-irradiation

    International Nuclear Information System (INIS)

    Fu Kaifei; Peng Ruiyun; Gao Yabing; Wang Dewen; Chen Haoyu; Wu Xiaohong; Yang Yi; Hu Wenhua; Ma Junjie

    2004-01-01

    Objective: To compare the pathologic characteristics of gut-associated lymphoid tissues and lymphocyte apoptosis in neutron-irradiated mouse small intestines with those in γ-irradiated ones. Methods: Altogether 350 BALB/c mice were irradiated with different doses of neutrons or γ-rays, and were sacrificed on 6 h,12 h,125 d, 7 d, 14 d, 21 d and 28 d after irradiation and their total intestines were removed. Then the pathologic changes and death mode of lymphocytes in gut-associated lymphoid tissues were studied comparatively with light microscopy, electron microscopy and in situ terminal labeling method. Results: The basic pathologic changes of gut-associated lymphoid tissues after neutron irradiation included degeneration, apoptosis and necrosis of lymphocytes. The number of lymphocytes also decreased. There was no obvious regeneration after 4.0 and 5.5 Gy neutron irradiation, while after 2.5 Gy regeneration and recovery appeared, which were, there fore, dose-dependent. In the 2.5 Gy neutron group, the numbers of lymphocytes of intramucosal and submucous lymphoid tissues decreased, and karyopyknosis and a great quantity of nuclear fragments could also be observed at 6 h-3 d after irradiation. However, on the 3rd day regeneration of crypt epithelial cells appeared. On the 5th day hyperplasia of submucous lymphocytic tissues appeared, but recovery to normal level was not achieved till 14 d after irradiation. The basic pathologic changes after γ-irradiation were similar to that of neutron irradiation. Regeneration and recovery appeared in the 5.5 Gy group while no obvious regeneration in the 12.0 Gy group. The results of in situ terminal labeling indicated that at 6 h after irradiation the number of apoptotic cells in gut-associated lymphoid tissues of each group increased obviously, while in 4.0 Gy neutron group and 12.0 Gy γ-ray group it was more abundant. Conclusion: Both 2.5-5.5 Gy neutron and 5.5-12.0 Gy γ-ray irradiation can induce obvious injuries in gut-associated

  12. BRAF inhibition is associated with increased clonality in tumor-infiltrating lymphocytes

    Science.gov (United States)

    Cooper, Zachary A; Frederick, Dennie T; Juneja, Vikram R; Sullivan, Ryan J; Lawrence, Donald P; Piris, Adriano; Sharpe, Arlene H; Fisher, David E; Flaherty, Keith T; Wargo, Jennifer A

    2013-01-01

    There have been significant advances with regard to BRAF-targeted therapies against metastatic melanoma. However, the majority of patients receiving BRAF inhibitors (BRAFi) manifest disease progression within a year. We have recently shown that melanoma patients treated with BRAFi exhibit an increase in melanoma-associated antigens and in CD8+ tumor-infiltrating lymphocytes in response to therapy. To characterize such a T-cell infiltrate, we analyzed the complementarity-determining region 3 (CDR3) of rearranged T-cell receptor (TCR) β chain-coding genes in tumor biopsies obtained before the initiation of BRAFi and 10–14 d later. We observed an increase in the clonality of tumor-infiltrating lymphocytes in 7 of 8 patients receiving BRAFi, with a statistically significant 21% aggregate increase in clonality. Over 80% of individual T-cell clones detected after initiation of BRAFi treatment were new clones. Interestingly, the comparison of tumor infiltrates with clinical responses revealed that patients who had a high proportion of pre-existing dominant clones after the administration of BRAFi responded better to therapy than patients who had a low proportion of such pre-existing dominant clones following BRAFi. These data suggest that although the inhibition of BRAF in melanoma patients results in tumor infiltration by new lymphocytes, the response to treatment appears to be related to the presence of a pre-existing population of tumor-infiltrating T-cell clones. PMID:24251082

  13. Effect on canine lymphocyte function of 144Ce inhaled in fused clay particles

    International Nuclear Information System (INIS)

    Benjamin, S.A.; Ferris, A.C.

    1974-01-01

    Beagle dogs exposed by inhalation to 144 Ce in fused clay particles develop a persistent lymphopenia and the remaining peripheral lymphocytes in these dogs show a depressed in vitro response to plant mitogens. These studies were designed to evaluate the cellular basis for this defect. The survival and growth of lymphocytes from irradiated and control dogs were evaluated through 96 hours of culture. Many irradiated lymphocytes that were viable in vivo died within 24 hours in vitro. The remaining lymphocytes appeared to grow normally indicating that the early in vitro death was responsible for at least a portion of the difference between irradiated and control lymphocyte cultures. A second experiment was designed to determine if any humoral factors in plasma of irradiated dogs were responsible for the poor response of the lymphocytes. Lymphocytes from irradiated and control dogs were grown with plasma from both types of animals. Heterologous plasma had no apparent effect on lymphocyte growth, indicating that humoral factors were not involved. (U.S.)

  14. A peptide affinity column for the identification of integrin alpha IIb-binding proteins.

    Science.gov (United States)

    Daxecker, Heide; Raab, Markus; Bernard, Elise; Devocelle, Marc; Treumann, Achim; Moran, Niamh

    2008-03-01

    To understand the regulation of integrin alpha(IIb)beta(3), a critical platelet adhesion molecule, we have developed a peptide affinity chromatography method using the known integrin regulatory motif, LAMWKVGFFKR. Using standard Fmoc chemistry, this peptide was synthesized onto a Toyopearl AF-Amino-650 M resin on a 6-aminohexanoic acid (Ahx) linker. Peptide density was controlled by acetylation of 83% of the Ahx amino groups. Four recombinant human proteins (CIB1, PP1, ICln and RN181), previously identified as binding to this integrin regulatory motif, were specifically retained by the column containing the integrin peptide but not by a column presenting an irrelevant peptide. Hemoglobin, creatine kinase, bovine serum albumin, fibrinogen and alpha-tubulin failed to bind under the chosen conditions. Immunodetection methods confirmed the binding of endogenous platelet proteins, including CIB1, PP1, ICln RN181, AUP-1 and beta3-integrin, from a detergent-free platelet lysate. Thus, we describe a reproducible method that facilitates the reliable extraction of specific integrin-binding proteins from complex biological matrices. This methodology may enable the sensitive and specific identification of proteins that interact with linear, membrane-proximal peptide motifs such as the integrin regulatory motif LAMWKVGFFKR.

  15. Force via integrins but not E-cadherin decreases Oct3/4 expression in embryonic stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Uda, Yuhei [Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States); Department of Biomedical Engineering, Graduate School of Biomedical Engineering, Tohoku University, 6-6-01, Aramaki-aoba, Aoba-ward, Sendai City (Japan); Poh, Yeh-Chuin; Chowdhury, Farhan; Wu, Douglas C. [Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States); Tanaka, Tetsuya S. [Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States); Sato, Masaaki [Department of Biomedical Engineering, Graduate School of Biomedical Engineering, Tohoku University, 6-6-01, Aramaki-aoba, Aoba-ward, Sendai City (Japan); Wang, Ning, E-mail: nwangrw@illinois.edu [Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States)

    2011-11-18

    Highlights: Black-Right-Pointing-Pointer Force via integrins or cadherins induces similar cell stiffening responses. Black-Right-Pointing-Pointer Force via integrins but not cadherins induces cell spreading. Black-Right-Pointing-Pointer Force via integrins but not cadherins induces differentiation of embryonic stem cells. -- Abstract: Increasing evidence suggests that mechanical factors play a critical role in fate decisions of stem cells. Recently we have demonstrated that a local force applied via Arg-Gly-Asp (RGD) peptides coated magnetic beads to mouse embryonic stem (ES) cells increases cell spreading and cell stiffness and decreases Oct3/4 (Pou5f1) gene expression. However, it is not clear whether the effects of the applied stress on these functions of ES cells can be extended to natural extracellular matrix proteins or cell-cell adhesion molecules. Here we show that a local cyclic shear force applied via fibronectin or laminin to integrin receptors increased cell spreading and stiffness, downregulated Oct3/4 gene expression, and decreased cell proliferation rate. In contrast, the same cyclic force applied via cell-cell adhesion molecule E-cadherin (Cdh1) had no effects on cell spreading, Oct3/4 gene expression, and the self-renewal of mouse ES cells, but induced significant cell stiffening. Our findings demonstrate that biological responses of ES cells to force applied via integrins are different from those to force via E-cadherin, suggesting that mechanical forces might play different roles in different force transduction pathways to shape early embryogenesis.

  16. Latent Lymphocytic Enterocolitis Associated with Celiac Disease Manifesting after Resection for Colon Cancer: Case Report and Review of the Literature

    Directory of Open Access Journals (Sweden)

    Vikram Tangri

    2008-01-01

    Full Text Available Lymphocytic colitis, a cause of chronic watery diarrhea, is histologically characterized by increased intraepithelial lymphocytosis. Studies have associated this disorder with celiac disease, although there are no reports of patients with both lymphocytic colitis and colon cancer. The present case report describes a patient with lymphocytic colitis, which manifested five years after he presented with a cecal adenocarcinoma, and three years following a diagnosis of celiac disease. Pathological review of his initial resection specimen demonstrated lymphocytic enterocolitis, indicating a five-year latency in the presentation of this disease.

  17. Lymphocytic Esophagitis: An Emerging Clinicopathologic Disease Associated with Dysphagia.

    Science.gov (United States)

    Pasricha, Sarina; Gupta, Amit; Reed, Craig C; Speck, Olga; Woosley, John T; Dellon, Evan S

    2016-10-01

    Lymphocytic esophagitis (LyE) is a recently described clinicopathological condition, but little is known about its features and clinical associations. The aim of this study was to characterize patients with LyE, compare them to non-LyE controls, and identify risk factors. We conducted a retrospective study of all patients ≥18 years old who underwent upper endoscopy with esophageal biopsy between January 1, 2000, and June 1, 2012. Archived pathology slides were re-reviewed, and LyE was diagnosed if there was lymphocyte-predominant esophageal inflammation with no eosinophils or granulocytes. Three non-LyE controls groups were also defined: reflux, eosinophilic esophagitis (EoE), and normal. Clinical data were extracted from electronic medical records, and LyE cases were compared to non-LyE controls. Twenty-seven adults were diagnosed with LyE, and the majority were female (63 %). The most common symptom was dysphagia (70 %). Fifty-two percentage had a prior or current diagnosis of reflux. Endoscopic findings included strictures (37 %), erosive esophagitis (33 %), rings (26 %), and hiatal hernia (26 %); 33 % of patients required dilation. After histology re-review, 78 % of LyE patients were found to have more than 20 lymphs/hpf. In comparison with the normal, reflux and EoE controls, patients with LyE tended to be nonwhite (p dysphagia due to esophageal strictures which require dilation. Smoking was associated with LyE, whereas atopy was not. LyE should be considered as a diagnostic possibility in patients with these characteristics undergoing upper endoscopy.

  18. Lymphocytic Esophagitis: An emerging clinicopathologic disease associated with dysphagia

    Science.gov (United States)

    Pasricha, Sarina; Gupta, Amit; Reed, Craig C.; Speck, Olga; Woosley, John T.; Dellon, Evan S.

    2016-01-01

    Background Lymphocytic Esophagitis (LyE) is a recently described clinicopathological condition, but little is known about its features and clinical associations. Aim To characterize patients with LyE, compare them to non-LyE controls, and identify risk factors. Methods We conducted a retrospective study of all patients ≥18 years old who underwent upper endoscopy with esophageal biopsy between January 1, 2000 and June 1, 2012. Archived pathology slides were re-reviewed and LyE was diagnosed if there was lymphocyte-predominant esophageal inflammation with no eosinophils or granulocytes. Three non-LyE controls groups were also defined: reflux, eosinophilic esophagitis (EoE), and normal. Clinical data were extracted from electronic medical records, and LyE cases were compared to non-LyE controls. Results 27 adults were diagnosed with LyE, and the majority were female (63%). The most common symptom was dysphagia (70%). 52% had a prior or current diagnosis of reflux. Endoscopic findings included strictures (37%), erosive esophagitis (33%), rings (26%), and hiatal hernia (26%); 33% of patients required dilation. After histology re-review, 78% of LyE patients were found to have more than 20 lymphs/hpf. In comparison to the normal, reflux and EoE controls, patients with LyE tended to be non-white (pdysphagia due to esophageal strictures which require dilation. Smoking was associated with LyE whereas atopy was not. LyE should be considered as a diagnostic possibility in patients with these characteristics undergoing upper endoscopy. PMID:27343035

  19. Integrins Regulate Apical Constriction via Microtubule Stabilization in the Drosophila Eye Disc Epithelium

    Directory of Open Access Journals (Sweden)

    Vilaiwan M. Fernandes

    2014-12-01

    Full Text Available During morphogenesis, extracellular signals trigger actomyosin contractility in subpopulations of cells to coordinate changes in cell shape. To illuminate the link between signaling-mediated tissue patterning and cytoskeletal remodeling, we study the progression of the morphogenetic furrow (MF, the wave of apical constriction that traverses the Drosophila eye imaginal disc preceding photoreceptor neurogenesis. Apical constriction depends on actomyosin contractility downstream of the Hedgehog (Hh and bone morphogenetic protein (BMP pathways. We identify a role for integrin adhesion receptors in MF progression. We show that Hh and BMP regulate integrin expression, the loss of which disrupts apical constriction and slows furrow progression; conversely, elevated integrins accelerate furrow progression. We present evidence that integrins regulate MF progression by promoting microtubule stabilization, since reducing microtubule stability rescues integrin-mediated furrow acceleration. Thus, integrins act as a genetic link between tissue-level signaling events and morphological change at the cellular level, leading to morphogenesis and neurogenesis in the eye.

  20. Anti-IL-5 attenuates activation and surface density of β2-integrins on circulating eosinophils after segmental antigen challenge

    Science.gov (United States)

    Johansson, Mats W.; Gunderson, Kristin A.; Kelly, Elizabeth A. B.; Denlinger, Loren C.; Jarjour, Nizar N.; Mosher, Deane F.

    2013-01-01

    minimal effects on properties of eosinophils in BAL. Dampening of β2-integrin function of eosinophils in transit to inflamed airway may contribute to the decrease in lung inflammation caused by anti-IL-5. PMID:23414537

  1. Effect of integrin α5β1 inhibition on SDF-l/CXCR4- mediated choroidal neovascularization

    Directory of Open Access Journals (Sweden)

    Yang Lyu

    2018-05-01

    Full Text Available AIM: To investigate the roles of integrins in choroidal neovascularization (CNV and their associations with the stromal cell-derived factor-1 (SDF-1/CXCR4 axis. METHODS: CNV lesions were induced in mice using laser photocoagulation. After CNV induction, all animals were randomly assigned to: control, SDF-1, SDF-1+age-related macular degeneration (AMD 3100 (CXCR4 inhibitor, and SDF-1+ATN161 (integrin α5β1 inhibitor groups; their effects on CNV progression were observed using hematoxylin eosin (HE staining, fundus fluorescein angiography (FFA grading and optical coherence tomography (OCT, and their effects on CXCR4/integrin α5 expression were evaluated using Western blot and double immunofluorescence staining. Hypoxia-exposed endothelial cells (ECs were used to simulate CNV in vitro, they were treated with SDF-1, combined with CXCR4 siRNA/AMD3100 or ATN161, and expression of integrin α5, cell migration and tube formation were analyzed. RESULTS: Integrin subunit α5 increased at 3rd and 7th day and decreased at 14th day in CNV mice, with no significant change of β1-integrin. CXCR4 expression in CNV mice had persistent increase within 14d after induction. SDF-1 treatment significantly promoted the CNV progression during 3-14d. The mean CNV length in AMD3100 and ATN161 group at day 7 was 270.13 and 264.23 μm in HE images, significantly lower than the mean length in SDF-1 (345.70 μm group. AMD3100 and ATN161 also significantly reduced thickness and leakage of CNV induced by SDF-1. Mean integrin α5 positive area in SDF-1 group reached 2.31×104 μm2, significantly higher than control (1.25×104 μm2, which decreased to 1.78×104 μm2 after AMD3100 treatment. About 61.36% of ECs in CNV lesions expressed α5 in SDF-1 group, which significantly decreased to 43.12% after AMD3100 treatment. In vitro, integrin α5 peaked by 6 folds after 6h of hypoxia exposure and CXCR4 gradually increased by up to 2.3 folds after 24h of hypoxia. Approximately 25

  2. Alterations in integrin expression modulates invasion of pancreatic cancer cells.

    LENUS (Irish Health Repository)

    Walsh, Naomi

    2009-01-01

    BACKGROUND: Factors mediating the invasion of pancreatic cancer cells through the extracellular matrix (ECM) are not fully understood. METHODS: In this study, sub-populations of the human pancreatic cancer cell line, MiaPaCa-2 were established which displayed differences in invasion, adhesion, anoikis, anchorage-independent growth and integrin expression. RESULTS: Clone #3 displayed higher invasion with less adhesion, while Clone #8 was less invasive with increased adhesion to ECM proteins compared to MiaPaCa-2. Clone #8 was more sensitive to anoikis than Clone #3 and MiaPaCa-2, and displayed low colony-forming efficiency in an anchorage-independent growth assay. Integrins beta 1, alpha 5 and alpha 6 were over-expressed in Clone #8. Using small interfering RNA (siRNA), integrin beta1 knockdown in Clone #8 cells increased invasion through matrigel and fibronectin, increased motility, decreased adhesion and anoikis. Integrin alpha 5 and alpha 6 knockdown also resulted in increased motility, invasion through matrigel and decreased adhesion. CONCLUSION: Our results suggest that altered expression of integrins interacting with different extracellular matrixes may play a significant role in suppressing the aggressive invasive phenotype. Analysis of these clonal populations of MiaPaCa-2 provides a model for investigations into the invasive properties of pancreatic carcinoma.

  3. Betal-integrins in the primary cilium of MDCK cells potentiate fibronectin-induced Ca2+ signalling

    DEFF Research Database (Denmark)

    Prætorius, Helle; Prætorius, Jeppe; Nielsen, Søren

    2004-01-01

    observed that β1-integrin, α3-integrin, and perhaps α5-integrin were localized to the primary cilium of MDCK cells by combining lectin and immunofluorescence confocal microscopy. β1-Integrin was also colocalized with tubulin to the primary cilia of the rat renal collecting ducts, as well as to the cilia...

  4. Cellular energy metabolism in T-lymphocytes.

    Science.gov (United States)

    Gaber, Timo; Strehl, Cindy; Sawitzki, Birgit; Hoff, Paula; Buttgereit, Frank

    2015-01-01

    Energy homeostasis is a hallmark of cell survival and maintenance of cell function. Here we focus on the impact of cellular energy metabolism on T-lymphocyte differentiation, activation, and function in health and disease. We describe the role of transcriptional and posttranscriptional regulation of lymphocyte metabolism on immune functions of T cells. We also summarize the current knowledge about T-lymphocyte adaptations to inflammation and hypoxia, and the impact on T-cell behavior of pathophysiological hypoxia (as found in tumor tissue, chronically inflamed joints in rheumatoid arthritis and during bone regeneration). A better understanding of the underlying mechanisms that control immune cell metabolism and immune response may provide therapeutic opportunities to alter the immune response under conditions of either immunosuppression or inflammation, potentially targeting infections, vaccine response, tumor surveillance, autoimmunity, and inflammatory disorders.

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

    LENUS (Irish Health Repository)

    Andrews, E J

    2012-02-03

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

  6. Residual activation events functional after irradiation of mouse splenic lymphocytes

    International Nuclear Information System (INIS)

    Duncan, D.D.; Lawrence, D.A.

    1991-01-01

    We have sought to identify the radiosensitivity of lymphocytes by determining the extent of activation of mitogen-stimulated lymphocytes previously exposed to growth-inhibiting doses of radiation. Mouse splenic lymphocytes were exposed to 0-15 Gy 137Cs radiation, and structural and functional damage were assayed. Although damage to cellular thiols and nonprotein thiols was modest, there was a significant loss of viability by 6 h as determined by uptake of propidium iodide (PI). Since cells did not die immediately after irradiation, the activation events which remained were evaluated. Growth-inhibiting doses of radiation left cells partially responsive to mitogen, in that cells were able to exit G0 phase, but they could progress no further into the cell cycle than G1a phase. It is important to note that assessment of viability by uptake of PI indicated substantial cell death after 15 Gy (45%, 6 h; 90%, 24 h); however, cell cycle analysis at 24 h indicated no significant decrease in progression from G0 to G1a phase. The LPS-stimulated response of B cells was more radiosensitive than the Con A-stimulated response of T cells. Further analysis of the Con A response indicated that production of interleukin-2 (IL-2) was unaffected, but expression of the IL-2 receptor was inhibited. Inhibition of poly-ADP-ribosylation and damage to lipids did not prevent the lack of mitogen responsiveness, since neither the ADP-ribose transferase inhibitor 3-aminobenzamide nor lipid radical scavengers had restorative effects on the mitogenic response. Nor was Con A-stimulated incorporation of [3H]thymidine restored with inhibitors of prostaglandin or leukotriene synthesis, suggesting that inhibition was due to direct effects on the Con A responders, and not indirect effects mediated by arachidonate metabolites

  7. Lymphocytic Esophagitis in Non-Achalasia Primary Esophageal Motility Disorders: Improved Criteria, Prevalence, Strength of Association and Natural History

    Science.gov (United States)

    Putra, Juan; Muller, Kristen E.; Hussain, Zilla H.; Parker, Siddhartha; Gabbard, Scott; Brickley, Elizabeth B.; Lacy, Brian E.; Rothstein, Richard; Lisovsky, Mikhail

    2017-01-01

    Lymphocytic esophagitis (LE) is a histologic pattern with no established clinical correlates in the majority of patients. The goal of this study was to evaluate the association between non-achalasia primary esophageal motility disorders (PMED) and LE. Sixty-nine patients with PMED and esophageal biopsies, including 22 with nutcracker esophagus, 33 with ineffective motility and 14 with diffuse spasm, constituted the study group. The control group consisted of 70 patients with severe dysmotility-negative gastroesophageal reflux disease (GERD) requiring referral for Nissen fundoplication. To improve the criteria for LE, a lymphocyte reference range at different esophageal levels was first established in 17 healthy volunteers. The cutoffs for normal intraepithelial lymphocytes (IEL), defined as lymphocyte levels not exceeding mean level + 2 standard deviations, were set at 62, 46, and 41 lymphocytes per high power field at 0 to 2 cm, 5 cm, and 10 cm above the gastroesophageal junction, respectively. Predominantly focal peripapillary LE was observed in approximately 40% of patients with nutcracker esophagus or diffuse spasm and 20% of patients with ineffective motility, in comparison to 4% of patients with dysmotility-negative GERD (P < 0.035 versus any subtype of PMED). Overall, LE was strongly associated with PMED in multivariate analysis (adjusted odds ratio, 7.93; 95% CI: 2.26, 27.9; P=0.001). LE had a chronic course in 56% of the patients with follow-up biopsies. In conclusion, LE has a strong association with PMED, suggesting utility of LE in raising the possibility of PMED. PMID:27526295

  8. The journey of integrins and partners in a complex interactions landscape studied by super-resolution microscopy and single protein tracking

    International Nuclear Information System (INIS)

    Rossier, Olivier; Giannone, Grégory

    2016-01-01

    Cells adjust their adhesive and cytoskeletal organizations according to changes in the biochemical and physical nature of their surroundings. In return, by adhering and generating forces on the extracellular matrix (ECM) cells organize their microenvironment. Integrin-dependent focal adhesions (FAs) are the converging zones integrating biochemical and biomechanical signals arising from the ECM and the actin cytoskeleton. Thus, integrin-mediated adhesion and mechanotransduction, the conversion of mechanical forces into biochemical signals, are involved in critical cellular functions such as migration, proliferation and differentiation, and their deregulation contributes to pathologies including cancer. A challenging problem is to decipher how stochastic protein movements and interactions lead to formation of dynamic architecture such as integrin-dependent adhesive structures. In this review, we will describe recent advances made possible by super-resolution microscopies and single molecule tracking approaches that provided new understanding on the organization and the dynamics of integrins and intracellular regulators at the nanoscale in living cells.

  9. The journey of integrins and partners in a complex interactions landscape studied by super-resolution microscopy and single protein tracking.

    Science.gov (United States)

    Rossier, Olivier; Giannone, Grégory

    2016-04-10

    Cells adjust their adhesive and cytoskeletal organizations according to changes in the biochemical and physical nature of their surroundings. In return, by adhering and generating forces on the extracellular matrix (ECM) cells organize their microenvironment. Integrin-dependent focal adhesions (FAs) are the converging zones integrating biochemical and biomechanical signals arising from the ECM and the actin cytoskeleton. Thus, integrin-mediated adhesion and mechanotransduction, the conversion of mechanical forces into biochemical signals, are involved in critical cellular functions such as migration, proliferation and differentiation, and their deregulation contributes to pathologies including cancer. A challenging problem is to decipher how stochastic protein movements and interactions lead to formation of dynamic architecture such as integrin-dependent adhesive structures. In this review, we will describe recent advances made possible by super-resolution microscopies and single molecule tracking approaches that provided new understanding on the organization and the dynamics of integrins and intracellular regulators at the nanoscale in living cells. Copyright © 2015. Published by Elsevier Inc.

  10. The journey of integrins and partners in a complex interactions landscape studied by super-resolution microscopy and single protein tracking

    Energy Technology Data Exchange (ETDEWEB)

    Rossier, Olivier; Giannone, Grégory [Univ. Bordeaux, Interdisciplinary Institute for Neuroscience, UMR 5297, F-33000 Bordeaux (France); CNRS, Interdisciplinary Institute for Neuroscience, UMR 5297, F-33000 Bordeaux (France)

    2016-04-10

    Cells adjust their adhesive and cytoskeletal organizations according to changes in the biochemical and physical nature of their surroundings. In return, by adhering and generating forces on the extracellular matrix (ECM) cells organize their microenvironment. Integrin-dependent focal adhesions (FAs) are the converging zones integrating biochemical and biomechanical signals arising from the ECM and the actin cytoskeleton. Thus, integrin-mediated adhesion and mechanotransduction, the conversion of mechanical forces into biochemical signals, are involved in critical cellular functions such as migration, proliferation and differentiation, and their deregulation contributes to pathologies including cancer. A challenging problem is to decipher how stochastic protein movements and interactions lead to formation of dynamic architecture such as integrin-dependent adhesive structures. In this review, we will describe recent advances made possible by super-resolution microscopies and single molecule tracking approaches that provided new understanding on the organization and the dynamics of integrins and intracellular regulators at the nanoscale in living cells.

  11. Pulmonary response to ozone: Reaction of bronchus-associated lymphoid tissue and lymph node lymphocytes in the rat

    International Nuclear Information System (INIS)

    Dziedzic, D.; Wright, E.S.; Sargent, N.E.

    1990-01-01

    The purpose of this work is to assess the effect of ozone, a reactive product of environmental photochemical oxidation, on lymphocytes of the lung. We exposed male Fischer rats to ozone at a concentration of 0.5 ppm for 20 hr/day for 1-14 days. Animals were treated with radioactive thymidine and were sacrificed at Day 1, 2, 3, 7, or 14 of exposure. Lungs and mediastinal lymph nodes were removed and prepared for histologic examination, evaluation of labeling indexes, and morphometric measurement. We examined two components of the lymphocyte response of the lung: the airway-related response, represented by the reaction of the bronchus-associated lymphoid tissue (BALT), and the deep lung-related response, represented by reaction of the mediastinal lymph node. Lymphocytes of both the BALT and the mediastinal lymph node showed elevated radioactive thymidine uptake; however, no evidence of cell death was observed at either site. The cells of the specialized epithelium covering the BALT (lymphoepithelium) showed increased vacuolization, indicating altered cellular function. The average size of BALTs was unchanged by ozone exposure. Under experimental conditions ozone can affect a variety of cells in the lung including bronchial epithelial cells, macrophages, and Type 1 cells. We have shown for the first time that in addition to these cells, the rat BALT also proliferates in response to ozone. In addition we confirm previous work in the mouse which shows that the mediastinal lymph node reacts as well. The airways can be affected by inflammation, can be targets of infection, and can respond to chemical irritants with bronchoconstrictive responses. They are an important target organ for hypersensitivity responses and are a primary site for pulmonary cancer formation. A role for lymphocytes has been implicated in each of these processes

  12. Integrins and small GTPases as modulators of phagocytosis.

    Science.gov (United States)

    Sayedyahossein, Samar; Dagnino, Lina

    2013-01-01

    Phagocytosis is the mechanism whereby cells engulf large particles. This process has long been recognized as a critical component of the innate immune response, which constitutes the organism's defense against microorganisms. In addition, phagocytic internalization of apoptotic cells or cell fragments plays important roles in tissue homeostasis and remodeling. Phagocytosis requires target interactions with receptors on the plasma membrane of the phagocytic cell. Integrins have been identified as important mediators of particle clearance, in addition to their well-established roles in cell adhesion, migration and mechanotransduction. Indeed, these ubiquitously expressed proteins impart phagocytic capacity to epithelial, endothelial and mesenchymal cell types. The importance of integrins in particle internalization is emphasized by the ability of microbial and viral pathogens to exploit their signaling pathways to invade host cells, and by the wide variety of disorders that arise from abnormalities in integrin-dependent phagocytic uptake. Copyright © 2013 Elsevier Inc. All rights reserved.

  13. Altered expression of adhesion molecules on peripheral blood leukocytes in feline infectious peritonitis.

    Science.gov (United States)

    Olyslaegers, Dominique A J; Dedeurwaerder, Annelike; Desmarets, Lowiese M B; Vermeulen, Ben L; Dewerchin, Hannah L; Nauwynck, Hans J

    2013-10-25

    Feline infectious peritonitis (FIP) is a fatal, coronavirus-induced systemic disease in domestic and wild felids. The pathology associated with FIP (multifocal granulomatous vasculitis) is considered to be elicited by exaggerated activation and subsequent extravasation of leukocytes. As changes in the expression of adhesion molecules on circulating leukocytes precede their margination and emigration, we reasoned that the expression of leukocyte adhesion molecules may be altered in FIP. In present study, the expression of principal adhesion molecules involved in leukocyte transmigration (CD15s, CD11a, CD11b, CD18, CD49d, and CD54) on peripheral blood leukocytes from cats with naturally occurring FIP (n=15) and controls (n=12) was quantified by flow cytometry using a formaldehyde-based rapid leukocyte preparation technique. T- and B-lymphocytes from FIP patients exhibit higher expression of both subunits (CD11a and CD18) composing the β2 integrin lymphocyte function-associated antigen (LFA)-1. In addition, the expression of the α4 subunit (CD49d) of the β1 integrin very late antigen (VLA)-4 was elevated on B-lymphocytes from FIP patients. The expression of CD11b and CD18, that combine to form the β2 integrin macrophage-1 antigen (Mac-1), was elevated on monocytes, whereas the density of CD49d was reduced on this population in FIP. Granulocytes of FIP cats displayed an increased expression of the α chain of Mac-1 (CD11b). These observations suggest that leukocytes from FIP patients show signs of systemic activation causing them to extravasate into surrounding tissues and ultimately contribute to pyogranuloma formation seen in FIP. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. Beta1 integrin-mediated adhesion signalling is essential for epidermal progenitor cell expansion

    DEFF Research Database (Denmark)

    Piwko-Czuchra, Aleksandra; Koegel, Heidi; Meyer, Hannelore

    2009-01-01

    BACKGROUND: There is a major discrepancy between the in vitro and in vivo results regarding the role of beta1 integrins in the maintenance of epidermal stem/progenitor cells. Studies of mice with skin-specific ablation of beta1 integrins suggested that epidermis can form and be maintained in thei...... of increased keratinocyte proliferation such as wound healing. CONCLUSIONS/SIGNIFICANCE: These data demonstrate that expression of beta1 integrins is critically important for the expansion of epidermal progenitor cells to maintain epidermal homeostasis....... that developed similar, but less severe defects than mice with beta1-deficient keratinocytes. Surprisingly we found that upon aging these abnormalities attenuated due to a rapid expansion of cells, which escaped or compensated for the down-regulation of beta1 integrin expression. A similar phenomenon...... was observed in aged mice with a complete, skin-specific ablation of the beta1 integrin gene, where cells that escaped Cre-mediated recombination repopulated the mutant skin in a very short time period. The expansion of beta1 integrin expressing keratinocytes was even further accelerated in situations...

  15. Disrupted lymphocyte homeostasis in hepatitis‐associated acquired aplastic anemia is associated with short telomeres

    Science.gov (United States)

    Babushok, Daria V.; Grignon, Anne‐Laure; Li, Yimei; Atienza, Jamie; Xie, Hongbo M.; Lam, Ho‐Sun; Hartung, Helge; Bessler, Monica

    2016-01-01

    Hepatitis‐associated aplastic anemia (HAA) is a variant of acquired aplastic anemia (AA) in which immune‐mediated bone marrow failure (BMF) develops following an acute episode of seronegative hepatitis. Dyskeratosis congenita (DC) is an inherited BMF syndrome characterized by the presence of short telomeres, mucocutaneous abnormalities, and cancer predisposition. While both conditions may cause BMF and hepatic impairment, therapeutic approaches are distinct, making it imperative to establish the correct diagnosis. In clinical practice, lymphocyte telomere lengths (TL) are used as a first‐line screen to rule out inherited telomeropathies before initiating treatment for AA. To evaluate the reliability of TL in the HAA population, we performed a retrospective analysis of TL in 10 consecutively enrolled HAA patients compared to 19 patients with idiopathic AA (IAA). HAA patients had significantly shorter telomeres than IAA patients (P = 0.009), including four patients with TL at or below the 1st percentile for age‐matched controls. HAA patients had no clinical features of DC and did not carry disease‐causing mutations in known genes associated with inherited telomere disorders. Instead, short TLs were significantly correlated with severe lymphopenia and skewed lymphocyte subsets, features characteristic of HAA. Our results indicate the importance of caution in the interpretation of TL measurements in HAA, because, in this patient population, short telomeres have limited specificity. Am. J. Hematol. 91:243–247, 2016. © 2015 The Authors. American Journal of Hematology Published by Wiley Periodicals, Inc. PMID:26615915

  16. Convulxin, a C-type lectin-like protein, inhibits HCASMCs functions via WAD-motif/integrin-αv interaction and NF-κB-independent gene suppression of GRO and IL-8.

    Science.gov (United States)

    Shih, Chun-Ho; Chiang, Tin-Bin; Wang, Wen-Jeng

    2017-03-15

    Convulxin (CVX), a C-type lectin-like protein (CLPs), is a potent platelet aggregation inducer. To evaluate its potential applications in angiogenic diseases, the multimeric CVX were further explored on its mode of actions toward human coronary artery smooth muscle cells (HCASMCs). The N-terminus of β-chain of CVX (CVX-β) contains a putative disintegrin-like domain with a conserved motif upon the sequence comparison with other CLPs. Importantly, native CVX had no cytotoxic activity as examined by electrophoretic pattern. A Trp-Ala-Asp (WAD)-containing octapeptide, MTWADAEK, was thereafter synthesized and analyzed in functional assays. In the case of specific integrin antagonists as positive controls, the anti-angiogenic effects of CVX on HCASMCs were investigated by series of functional analyses. CVX showed to exhibit multiple inhibitory activities toward HCASMCs proliferation, adhesion and invasion with a dose- and integrin αvβ3-dependent fashion. However, the WAD-octapeptide exerting a minor potency could also work as an active peptidomimetic. In addition, flow cytometric analysis demonstrated both the intact CVX and synthetic peptide can specifically interact with integrin-αv on HCASMCs and CVX was shown to have a down-regulatory effect on the gene expression of CXC-chemokines, such as growth-related oncogene and interleukin-8. According to nuclear factor-κB (NF-κB) p65 translocation assay and Western blotting analysis, the NF-κB activation was not involved in the signaling events of CVX-induced gene expression. In conclusion, CVX may act as a disintegrin-like protein via the interactions of WAD-motif in CVX-β with integrin-αv on HCASMCs and it also is a gene suppressor with the ability to diminish the expression of two CXC-chemokines in a NF-κB-independent manner. Indeed, more extensive investigations are needed and might create a new avenue for the development of a novel angiostatic agent. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Integrins beta 5, beta 3 and alpha v are apically distributed in endometrial epithelium.

    Science.gov (United States)

    Aplin, J D; Spanswick, C; Behzad, F; Kimber, S J; Vićovac, L

    1996-07-01

    Several adhesion molecules have been shown to occur at the surface of endometrial cells. One of these is the integrin alpha v subunit which associates with various beta chains including beta 5. We demonstrate the presence of integrin beta 5 polypeptide in human endometrial epithelial cells throughout the menstrual cycle using immunocytochemistry with monospecific antibodies, and at the mRNA level by thermal amplification from endometrial cDNA. Integrin beta 5 is also found in a population of bone marrow-derived cells. A notable feature of the distribution of the beta 5 subunit in the glandular and luminal epithelium is its apical localization, which may suggest an involvement in implantation. However, no evidence was found for regulated expression of epithelial beta 5. In mouse, the beta 5 subunit is found at both the apical and basal surface of epithelial cells and expression is essentially oestrous cycle-independent. Comparisons are made in both species with the distribution of the alpha v and beta 3 subunits which also localize to the apical epithelium.

  18. Phospho-Tyrosine(s) vs. Phosphatidylinositol Binding in Shc Mediated Integrin Signaling.

    Science.gov (United States)

    Lin, Xiaochen; Vinogradova, Olga

    2015-04-01

    The Shc adaptor protein, particularly its p52 isoform, has been identified as a primary signaling partner for the tyrosine(s)-phosphorylated cytoplasmic tails of activated β 3 integrins. Inspired by our recent structure of the Shc PTB domain in complex with a bi-phosphorylated peptide derived from β 3 cytoplasmic tail, we have initiated the investigation of Shc interaction with phospholipids of the membrane. We are particularly focused on PtdIns and their effects on Shc mediated integrin signaling in vitro . Here we present thermodynamic profiles and molecular details of the interactions between Shc, integrin, and PtdIns, all of which have been studied by ITC and solution NMR methods. A model of p52 Shc interaction with phosphorylated β 3 integrin cytoplasmic tail at the cytosolic face of the plasma membrane is proposed based on these data.

  19. Mechanical control of cyclic AMP signalling and gene transcription through integrins

    Science.gov (United States)

    Meyer, C. J.; Alenghat, F. J.; Rim, P.; Fong, J. H.; Fabry, B.; Ingber, D. E.

    2000-01-01

    This study was carried out to discriminate between two alternative hypotheses as to how cells sense mechanical forces and transduce them into changes in gene transcription. Do cells sense mechanical signals through generalized membrane distortion or through specific transmembrane receptors, such as integrins? Here we show that mechanical stresses applied to the cell surface alter the cyclic AMP signalling cascade and downstream gene transcription by modulating local release of signals generated by activated integrin receptors in a G-protein-dependent manner, whereas distortion of integrins in the absence of receptor occupancy has no effect.

  20. Opinion: Interactions of innate and adaptive lymphocytes

    Science.gov (United States)

    Gasteiger, Georg; Rudensky, Alexander Y.

    2015-01-01

    Innate lymphocytes, including natural killer (NK) cells and the recently discovered innate lymphoid cells (ILCs) have crucial roles during infection, tissue injury and inflammation. Innate signals regulate the activation and homeostasis of innate lymphocytes. Less well understood is the contribution of the adaptive immune system to the orchestration of innate lymphocyte responses. We review our current understanding of the interactions between adaptive and innate lymphocytes, and propose a model in which adaptive T cells function as antigen-specific sensors for the activation of innate lymphocytes to amplify and instruct local immune responses. We highlight the potential role of regulatory and helper T cells in these processes and discuss major questions in the emerging area of crosstalk between adaptive and innate lymphocytes. PMID:25132095

  1. The role of alpha3beta1 integrin in determining the supramolecular organization of laminin-5 in the extracellular matrix of keratinocytes.

    Science.gov (United States)

    deHart, Gregory W; Healy, Kevin E; Jones, Jonathan C R

    2003-02-01

    Analyses of mice with targeted deletions in the genes for alpha3 and beta1 integrin suggest that the alpha3beta1 integrin heterodimer likely determines the organization of the extracellular matrix within the basement membrane of skin. Here we tested this hypothesis using keratinocytes derived from alpha3 integrin-null mice. We have compared the organizational state of laminin-5, a ligand of alpha3beta1 integrin, in the matrix of wild-type keratinocytes with that of laminin-5 in the matrix of alpha3 integrin-null cells. Laminin-5 distributes diffusely in arc structures in the matrix of wild-type mouse keratinocytes, whereas laminin-5 is organized into linear, spike-like arrays by the alpha3 integrin-null cells. The fact that alpha3 integrin-null cells are deficient in their ability to assemble a proper laminin-5 matrix is also shown by their failure to remodel laminin-5 when plated onto surfaces coated with purified laminin-5 protein. In sharp contrast, wild-type keratinocytes organize exogenously added laminin-5 into discrete ring-like organizations. These findings led us next to assess whether differences in laminin-5 organization in the matrix of the wild-type and alpha3 integrin-null cells impact cell behavior. Our results indicate that alpha3 integrin-null cells are more motile than their wild-type counterparts and leave extensive trails of laminin-5 over the surface on which they move. Moreover, HEK 293 cells migrate significantly more on the laminin-5-rich matrix derived from the alpha3 integrin-null cells than on the wild-type keratinocyte laminin-5 matrix. In addition, alpha3 integrin-null cells show low strength of adhesion to surfaces coated with purified laminin-5 compared to wild-type cells although both the wild type and the alpha3 integrin-null keratinocytes adhere equally strongly to laminin-5 that has been organized into arrays by other epithelial cells. These data suggest: (1) that alpha3beta1 integrin plays an important role in determining the

  2. 1α,25(OH2 Vitamin D3 Modulates Avian T Lymphocyte Functions without Inducing CTL Unresponsiveness.

    Directory of Open Access Journals (Sweden)

    Nitish Boodhoo

    Full Text Available 1,25-Dihydroxyvitamin D3 (Vitamin D is a naturally synthesized fat soluble vitamin shown to have immunomodulatory, anti-inflammatory and cancer prevention properties in human and murine models. Here, we studied the effects of Vitamin D on the functional abilities of avian T lymphocytes using chicken Interferon (IFN-γ ELISPOT assay, BrdU proliferation assay, Annexin V apoptosis assay and PhosFlow for detecting phosphorylated signalling molecules. The results demonstrate that Vitamin D significantly inhibited the abilities of T lymphocytes to produce IFN-γ and proliferate in vitro (P≤0.05, but retained their ability to undergo degranulation, which is a maker for cytotoxicity of these cells. Similarly, Vitamin D did not inhibit Extracellular signal-Regulated Kinase (ERK 1/2 phosphorylation, a key mediator in T cell signalling, in the stimulated T lymphocytes population, while reduced ERK1/2 phosphorylation levels in the unstimulated cells. Our data provide evidence that Vitamin D has immuno-modulatory properties on chicken T lymphocytes without inducing unresponsiveness and by limiting immuno-pathology can promote protective immunity against infectious diseases of poultry.

  3. Hypercalcaemia associated with chronic lymphocytic leukaemia in a Giant Schnauzer.

    Science.gov (United States)

    Kleiter, M; Hirt, R; Kirtz, G; Day, M J

    2001-05-01

    A 7-year-old male Giant Schnauzer was referred with a history of severe vomiting, lethargy, weight loss, polydipsia and polyuria. Detailed investigations revealed leucocytosis with a marked lymphocytosis, mild non-regenerative anaemia, thrombocytopenia, hypercalcaemia and azotaemia. Circulating lymphocytes were small and well-differentiated, and the same lymphoid population was present in bone marrow. Chronic lymphocyctic leukaemia with associated paraneoplastic hypercalcaemia was diagnosed. Immunohistochemical staining of a bone marrow biopsy revealed a neoplastic B-cell line expressing CD79. The dog responded to therapy with prednisolone and chlorambucil for a period of 8 months.

  4. Beta1 integrin-mediated adhesion signalling is essential for epidermal progenitor cell expansion.

    Directory of Open Access Journals (Sweden)

    Aleksandra Piwko-Czuchra

    Full Text Available BACKGROUND: There is a major discrepancy between the in vitro and in vivo results regarding the role of beta1 integrins in the maintenance of epidermal stem/progenitor cells. Studies of mice with skin-specific ablation of beta1 integrins suggested that epidermis can form and be maintained in their absence, while in vitro data have shown a fundamental role for these adhesion receptors in stem/progenitor cell expansion and differentiation. METHODOLOGY/PRINCIPAL FINDINGS: To elucidate this discrepancy we generated hypomorphic mice expressing reduced beta1 integrin levels on keratinocytes that developed similar, but less severe defects than mice with beta1-deficient keratinocytes. Surprisingly we found that upon aging these abnormalities attenuated due to a rapid expansion of cells, which escaped or compensated for the down-regulation of beta1 integrin expression. A similar phenomenon was observed in aged mice with a complete, skin-specific ablation of the beta1 integrin gene, where cells that escaped Cre-mediated recombination repopulated the mutant skin in a very short time period. The expansion of beta1 integrin expressing keratinocytes was even further accelerated in situations of increased keratinocyte proliferation such as wound healing. CONCLUSIONS/SIGNIFICANCE: These data demonstrate that expression of beta1 integrins is critically important for the expansion of epidermal progenitor cells to maintain epidermal homeostasis.

  5. Mitochondrial DNA copy number and chronic lymphocytic leukemia/small lymphocytic lymphoma risk in two prospective studies

    NARCIS (Netherlands)

    Kim, Christopher; Bassig, Bryan A; Seow, Wei Jie; Hu, Wei; Purdue, Mark P; Huang, Wen-Yi; Liu, Chin-San; Cheng, Wen-Ling; Männistö, Satu; Vermeulen, Roel; Weinstein, Stephanie J; Lim, Unhee; Hosgood, H Dean; Bonner, Matthew R; Caporaso, Neil E; Albanes, Demetrius; Lan, Qing; Rothman, Nathaniel

    BACKGROUND: Mitochondrial DNA copy number (mtDNA CN) may be modified by mitochondria in response to oxidative stress. Previously, mtDNA CN was associated with non-Hodgkin lymphoma (NHL) risk, particularly chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL). We conducted a replication

  6. Ouabain interactions with the α4 isoform of the sodium pump trigger non-classical steroid hormone signaling and integrin expression in spermatogenic cells.

    Science.gov (United States)

    Upmanyu, Neha; Dietze, Raimund; Kirch, Ulrike; Scheiner-Bobis, Georgios

    2016-11-01

    In addition to the ubiquitous α1 isoform of the sodium pump, sperm cells also express a male-specific α4 isoform whose function has been associated with sperm motility, fertility, and capacitation. Here we investigate in the murine spermatogenic cell line GC-2 interactions of the α4 isoform with the cardiotonic steroid ouabain in signaling cascades involved in the non-classical action of steroid hormones. Exposure of GC-2 cells to low concentrations of ouabain stimulates the phosphorylation of Erk1/2 and of the transcription factors CREB and ATF-1. As a consequence of this signaling cascade, ouabain stimulates on the mRNA level the expression of integrins αv, β3 and α5, whose expression is also modulated by the cAMP response element. Increased expression of integrins αv and β3 is also seen in cultures of seminiferous tubules exposed to 10nM ouabain. At the protein level we observed a significant stimulation of β3 integrin expression by ouabain. Abrogation of α4 isoform expression by siRNA leads to the complete suppression of all ouabain-induced signaling mentioned above, including its stimulatory effect on the expression of β3 integrin. The results presented here demonstrate for the first time the induction of signaling cascades through the interaction of ouabain with the α4 isoform in a germ-cell derived cell line. The novel finding that these interactions lead to increased expression of integrins in GC-2 cells and the confirmation of these results in the ex vivo experiments indicate that hormone/receptor-like interactions of ouabain with the α4 isoform might be of significance for male physiology. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Acute Podocyte Vascular Endothelial Growth Factor (VEGF-A) Knockdown Disrupts alphaVbeta3 Integrin Signaling in the Glomerulus

    Science.gov (United States)

    Veron, Delma; Villegas, Guillermo; Aggarwal, Pardeep Kumar; Bertuccio, Claudia; Jimenez, Juan; Velazquez, Heino; Reidy, Kimberly; Abrahamson, Dale R.; Moeckel, Gilbert; Kashgarian, Michael; Tufro, Alda

    2012-01-01

    Podocyte or endothelial cell VEGF-A knockout causes thrombotic microangiopathy in adult mice. To study the mechanism involved in acute and local injury caused by low podocyte VEGF-A we developed an inducible, podocyte-specific VEGF-A knockdown mouse, and we generated an immortalized podocyte cell line (VEGFKD) that downregulates VEGF-A upon doxycycline exposure. Tet-O-siVEGF:podocin-rtTA mice express VEGF shRNA in podocytes in a doxycycline-regulated manner, decreasing VEGF-A mRNA and VEGF-A protein levels in isolated glomeruli to ∼20% of non-induced controls and urine VEGF-A to ∼30% of control values a week after doxycycline induction. Induced tet-O-siVEGF:podocin-rtTA mice developed acute renal failure and proteinuria, associated with mesangiolysis and microaneurisms. Glomerular ultrastructure revealed endothelial cell swelling, GBM lamination and podocyte effacement. VEGF knockdown decreased podocyte fibronectin and glomerular endothelial alphaVbeta3 integrin in vivo. VEGF receptor-2 (VEGFR2) interacts with beta3 integrin and neuropilin-1 in the kidney in vivo and in VEGFKD podocytes. Podocyte VEGF knockdown disrupts alphaVbeta3 integrin activation in glomeruli, detected by WOW1-Fab. VEGF silencing in cultured VEGFKD podocytes downregulates fibronectin and disrupts alphaVbeta3 integrin activation cell-autonomously. Collectively, these studies indicate that podocyte VEGF-A regulates alphaVbeta3 integrin signaling in the glomerulus, and that podocyte VEGF knockdown disrupts alphaVbeta3 integrin activity via decreased VEGFR2 signaling, thereby damaging the three layers of the glomerular filtration barrier, causing proteinuria and acute renal failure. PMID:22808199

  8. Adhesion- and stress-related adaptation of glioma radiochemoresistance is circumvented by β1 integrin/JNK co-targeting.

    Science.gov (United States)

    Vehlow, Anne; Klapproth, Erik; Storch, Katja; Dickreuter, Ellen; Seifert, Michael; Dietrich, Antje; Bütof, Rebecca; Temme, Achim; Cordes, Nils

    2017-07-25

    Resistance of cancer stem-like and cancer tumor bulk cells to radiochemotherapy and destructive infiltration of the brain fundamentally influence the treatment efficiency to cure of patients suffering from Glioblastoma (GBM). The interplay of adhesion and stress-related signaling and activation of bypass cascades that counteract therapeutic approaches remain to be identified in GBM cells. We here show that combined inhibition of the adhesion receptor β1 integrin and the stress-mediator c-Jun N-terminal kinase (JNK) induces radiosensitization and blocks invasion in stem-like and patient-derived GBM cultures as well as in GBM cell lines. In vivo, this treatment approach not only significantly delays tumor growth but also increases median survival of orthotopic, radiochemotherapy-treated GBM mice. Both, in vitro and in vivo, effects seen with β1 integrin/JNK co-inhibition are superior to the monotherapy. Mechanistically, the in vitro radiosensitization provoked by β1 integrin/JNK targeting is caused by defective DNA repair associated with chromatin changes, enhanced ATM phosphorylation and prolonged G2/M cell cycle arrest. Our findings identify a β1 integrin/JNK co-dependent bypass signaling for GBM therapy resistance, which might be therapeutically exploitable.

  9. Integrin {alpha}{beta}1, {alpha}{sub v}{beta}, {alpha}{sub 6}{beta} effectors p130Cas, Src and talin regulate carcinoma invasion and chemoresistance

    Energy Technology Data Exchange (ETDEWEB)

    Sansing, Hope A. [Department of Oral and Craniofacial Biology, Louisiana State University Health Sciences Center-New Orleans, School of Dentistry, New Orleans, LA (United States); Sarkeshik, Ali; Yates, John R. [Department of Chemical Physiology, Scripps Research Institute, La Jolla, CA (United States); Patel, Vyomesh; Gutkind, J. Silvio [Oral and Pharyngeal Cancer Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD (United States); Yamada, Kenneth M. [Laboratory of Cell and Developmental Biology, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD (United States); Berrier, Allison L., E-mail: allison.berrier@gmail.com [Department of Oral and Craniofacial Biology, Louisiana State University Health Sciences Center-New Orleans, School of Dentistry, New Orleans, LA (United States)

    2011-03-11

    Research highlights: {yields} Proteomics of clustered integrin {alpha}{beta}1, {alpha}{sub v}{beta}, {alpha}{sub 6}{beta} receptors in oral carcinoma. {yields} p130Cas, Dek, Src and talin regulate oral carcinoma invasion. {yields} p130Cas, talin, Src and zyxin regulate oral carcinoma resistance to cisplatin. -- Abstract: Ligand engagement by integrins induces receptor clustering and formation of complexes at the integrin cytoplasmic face that controls cell signaling and cytoskeletal dynamics critical for adhesion-dependent processes. This study searches for a subset of integrin effectors that coordinates both tumor cell invasion and resistance to the chemotherapeutic drug cisplatin in oral carcinomas. Candidate integrin effectors were identified in a proteomics screen of proteins recruited to clustered integrin {alpha}{beta}1, {alpha}{sub v}{beta} or {alpha}{sub 6}{beta} receptors in oral carcinomas. Proteins with diverse functions including microtubule and actin binding proteins, and factors involved in trafficking, transcription and translation were identified in oral carcinoma integrin complexes. Knockdown of effectors in the oral carcinoma HN12 cells revealed that p130Cas, Dek, Src and talin were required for invasion through Matrigel. Disruption of talin or p130Cas by RNA interference increased resistance to cisplatin, whereas targeting Dek, Src or zyxin reduced HN12 resistance to cisplatin. Analysis of the spreading of HN12 cells on collagen I and laminin I revealed that a decrease in p130Cas or talin expression inhibited spreading on both matrices. Interestingly, a reduction in zyxin expression enhanced spreading on laminin I and inhibited spreading on collagen I. Reduction of Dek, Src, talin or zyxin expression reduced HN12 proliferation by 30%. Proliferation was not affected by a reduction in p130Cas expression. We conclude that p130Cas, Src and talin function in both oral carcinoma invasion and resistance to cisplatin.

  10. Syndecan-4 Phosphorylation Is a Control Point for Integrin Recycling

    Science.gov (United States)

    Morgan, Mark R.; Hamidi, Hellyeh; Bass, Mark D.; Warwood, Stacey; Ballestrem, Christoph; Humphries, Martin J.

    2013-01-01

    Summary Precise spatiotemporal coordination of integrin adhesion complex dynamics is essential for efficient cell migration. For cells adherent to fibronectin, differential engagement of α5β1 and αVβ3 integrins is used to elicit changes in adhesion complex stability, mechanosensation, matrix assembly, and migration, but the mechanisms responsible for receptor regulation have remained largely obscure. We identify phosphorylation of the membrane-intercalated proteoglycan syndecan-4 as an essential switch controlling integrin recycling. Src phosphorylates syndecan-4 and, by driving syntenin binding, leads to suppression of Arf6 activity and recycling of αVβ3 to the plasma membrane at the expense of α5β1. The resultant elevation in αVβ3 engagement promotes stabilization of focal adhesions. Conversely, abrogation of syndecan-4 phosphorylation drives surface expression of α5β1, destabilizes adhesion complexes, and disrupts cell migration. These data identify the dynamic spatiotemporal regulation of Src-mediated syndecan-4 phosphorylation as an essential switch controlling integrin trafficking and adhesion dynamics to promote efficient cell migration. PMID:23453597

  11. Ibrutinib modifies the function of monocyte/macrophage population in chronic lymphocytic leukemia.

    Science.gov (United States)

    Fiorcari, Stefania; Maffei, Rossana; Audrito, Valentina; Martinelli, Silvia; Ten Hacken, Elisa; Zucchini, Patrizia; Grisendi, Giulia; Potenza, Leonardo; Luppi, Mario; Burger, Jan A; Deaglio, Silvia; Marasca, Roberto

    2016-10-04

    In lymphoid organs, nurse-like cells (NLCs) show properties of tumor-associated macrophages, playing a crucial role in chronic lymphocytic leukemia (CLL) cell survival. Ibrutinib, a potent inhibitor of Bruton's tyrosine kinase (BTK), is able to counteract pro-survival signals in CLL cells. Since the effects on CLL cells have been studied in the last years, less is known about the influence of ibrutinib on NLCs properties. We sought to determine how ibrutinib modifies NLCs functions focusing on the balance between immunosuppressive and inflammatory features. Our data show that ibrutinib targets BTK expressed by NLCs modifying their phenotype and function. Treatment with ibrutinib reduces the phagocytic ability and increases the immunosuppressive profile of NLCs exacerbating the expression of M2 markers. Accordingly, ibrutinib hampers LPS-mediated signaling, decreasing STAT1 phosphorylation, while allows IL-4-mediated STAT6 phosphorylation. In addition, NLCs treated with ibrutinib are able to protect CLL cells from drug-induced apoptosis partially through the secretion of IL-10. Results from patient samples obtained prior and after 1 month of treatment with ibrutinib show an accentuation of CD206, CD11b and Tie2 in the monocytic population in the peripheral blood. Our study provides new insights into the immunomodulatory action of ibrutinib on monocyte/macrophage population in CLL.

  12. Damage of lymphocytes by ionizing irradiation

    International Nuclear Information System (INIS)

    Rose, H.; Moldenhauer, H.; Kehrberg, G.

    1985-01-01

    After a short review, how lymphocytes of the peripheral blood are influenced by radiotherapy, the damage of lymphocytes by whole-body irradiation is pointed out in animal experiments and after in vitro irradiation. The special sensibility of B-cells and their homogeneity in fields of radiobiology are opposed to the heterogeneity of T-cells. The radiosensibility of cytotoxic lymphocytes, suppressor cells, and helper cells are discussed. It appears, that within these functional criteria, there is a different radiosensibility, too. (author)

  13. Role of β1 Integrin in Tissue Homing of Neutrophils During Sepsis

    Science.gov (United States)

    Sarangi, Pranita P.; Hyun, Young-Min; Lerman, Yelena V.; Pietropaoli, Anthony P.; Kim, Minsoo

    2012-01-01

    Aberrant activation of neutrophils during sepsis results in the widespread release of pro-inflammatory mediators, leading to multi-organ system failure and death. However, aberrant activation of neutrophils during sepsis results in the widespread release of harmful inflammatory mediators causing host tissue injuries that can lead to multi organ system failure and death. One of the pivotal components of neutrophil migration during inflammation is the expression of surface integrins. In this study, we show that administration of a cyclic analog of RGD peptide (Arg-Gly-Asp) significantly reduced the number of tissue-invading neutrophils and the degree of sepsis-induced lethality in mice as compared to control peptide. Secondly, β1 integrin (CD29) was highly up-regulated on the neutrophils isolated from both septic patients and animals. Finally, conditional genetic ablation of β1 integrin from granulocytes also improved survival and bacterial clearance in septic animals Thus, our results indicate that expression of β1 integrin is important for modulating neutrophil trafficking during sepsis, and that therapeutics designed against β1 integrins may be beneficial. PMID:22683734

  14. Arginylglycylaspartic Acid-Surface-Functionalized Doxorubicin-Loaded Lipid-Core Nanocapsules as a Strategy to Target Alpha(V) Beta(3) Integrin Expressed on Tumor Cells

    Science.gov (United States)

    Antonow, Michelli B.; Franco, Camila; Prado, Willian; Beckenkamp, Aline; Silveira, Gustavo P.; Buffon, Andréia; Guterres, Sílvia S.

    2017-01-01

    Doxorubicin (Dox) clinical use is limited by dose-related cardiomyopathy, becoming more prevalent with increasing cumulative doses. Previously, we developed Dox-loaded lipid-core nanocapsules (Dox-LNC) and, in this study, we hypothesized that self-assembling and interfacial reactions could be used to obtain arginylglycylaspartic acid (RGD)-surface-functionalized-Dox-LNC, which could target tumoral cells overexpressing αvβ3 integrin. Human breast adenocarcinoma cell line (MCF-7) and human glioblastoma astrocytoma (U87MG) expressing different levels of αvβ3 integrin were studied. RGD-functionalized Dox-LNC were prepared with Dox at 100 and 500 mg·mL−1 (RGD-MCMN (Dox100) and RGD-MCMN (Dox500)). Blank formulation (RGD-MCMN) had z-average diameter of 162 ± 6 nm, polydispersity index of 0.11 ± 0.04, zeta potential of +13.2 ± 1.9 mV and (6.2 ± 1.1) × 1011 particles mL−1, while RGD-MCMN (Dox100) and RGD-MCMN (Dox500) showed respectively 146 ± 20 and 215 ± 25 nm, 0.10 ± 0.01 and 0.09 ± 0.03, +13.8 ± 2.3 and +16.4 ± 1.5 mV and (6.9 ± 0.6) × 1011 and (6.1 ± 1.0) × 1011 particles mL−1. RGD complexation was 7.73 × 104 molecules per nanocapsule and Dox loading were 1.51 × 104 and 7.64 × 104 molecules per nanocapsule, respectively. RGD-functionalized nanocapsules had an improved uptake capacity by U87MG cells. Pareto chart showed that the cell viability was mainly affected by the Dox concentration and the period of treatment in both MCF-7 and U87MG. The influence of RGD-functionalization on cell viability was a determinant factor exclusively to U87MG. PMID:29271920

  15. Chondroitin Sulfate-E Binds to Both Osteoactivin and Integrin αVβ3 and Inhibits Osteoclast Differentiation.

    Science.gov (United States)

    Miyazaki, Tatsuya; Miyauchi, Satoshi; Anada, Takahisa; Tawada, Akira; Suzuki, Osamu

    2015-10-01

    Integrins and their ligands have been suggested to be associated with osteoclast-mediated bone resorption. The present study was designed to investigate whether chondroitin sulfate E (CS-E), which is one of the sulfated glycosaminoglycans (GAGs), is involved in osteoactivin (OA) activity, and osteoclast differentiation. The binding affinity of sulfated GAGs to integrin and its ligand was measured using biotin-labeled CS-E, and the osteoclast differentiation was evaluated by tartrate-resistant acid phosphatase staining and a pit formation assay. CS-E as well as CS-B, synthetic chondroitin polysulfate, and heparin inhibited osteoclast differentiation of bone marrow-derived macrophages. Pre-coating of OA to synthetic calcium phosphate-coated plates enhanced the osteoclastic differentiation of RAW264 cells, and addition of a neutralizing antibody to OA inhibited its differentiation. CS-E bound not only to OA, fibronectin, and vitronectin, but also to its receptor integrin αVβ3, and inhibited the direct binding of OA to integrin αVβ3. Furthermore, CS-E blocked the binding of OA to cells and inhibited OA-induced osteoclastic differentiation. On the other hand, heparinase treatment of RAW264 cells inhibited osteoclastic differentiation. Since binding of OA to the cells was inhibited by the presence of heparan sulfate or heparinase treatment of cells, heparan sulfate proteoglycan (HSPG) was also considered to be an OA receptor. Taken together, the present results suggest that CS-E is capable of inhibiting OA-induced osteoclast differentiation by blocking the interaction of OA to integrin αVβ3 and HSPG. © 2015 Wiley Periodicals, Inc.

  16. Communication between integrin receptors facilitates epicardial cell adhesion and matrix organization.

    Science.gov (United States)

    Pae, So Hyun; Dokic, Danijela; Dettman, Robert W

    2008-04-01

    Formation of the epicardium requires interactions between alpha(4)beta(1) integrin, and the extracellular matrix. We investigated the role of other integrins expressed by epicardial cells. We detected transcripts for alpha(5), alpha(8), alpha(v), beta(1), beta(3), and beta(5) integrins in the chick proepicardial organ (PE). We demonstrate that alpha(5)beta(1), alpha(8)beta(1), and alpha(v)beta(3) integrins are expressed by chick epicardial mesothelial cells (EMCs). Migration of EMCs in vitro was reduced by RGD-containing peptides. Using adenoviruses expressing an antisense to chick alpha(4) (AdGFPalpha4AS), full-length (Adhalpha4V5), and C-terminal deleted alpha(4) (Adhalpha4DeltaCV5), we found that EMCs were less able to adhere to vitronectin and fibronectin(120) indicating that alpha(4)beta(1) plays a role in regulating EMC adhesion to ligands of alpha(5)beta(1), alpha(8)beta(1), and alpha(v)beta(3). In Adhalpha4DeltaCV5-infected EMCs, alpha(5)beta(1) was diminished in fibrillar adhesions and new FN matrix assembly was abnormal. We propose that cooperation between alpha(4)beta(1) and RGD integrins is important for EMC adhesion and subepicardial matrix formation. (c) 2008 Wiley-Liss, Inc.

  17. Essential role of integrin-linked kinase in regulation of phagocytosis in keratinocytes.

    Science.gov (United States)

    Sayedyahossein, Samar; Nini, Lylia; Irvine, Timothy S; Dagnino, Lina

    2012-10-01

    Phagocytic melanosome uptake by epidermal keratinocytes is a central protective mechanism against damage induced by ultraviolet radiation. Phagocytosis requires formation of pseudopodia via actin cytoskeleton rearrangements. Integrin-linked kinase (ILK) is an important modulator of actin cytoskeletal dynamics. We have examined the role of ILK in regulation of phagocytosis, using epidermal keratinocytes isolated from mice with epidermis-restricted Ilk gene inactivation. ILK-deficient cells exhibited severely impaired capacity to engulf fluorescent microspheres in response to stimulation of the keratinocyte growth factor (KGF) receptor or the protease-activated receptor-2. KGF induced ERK phosphorylation in ILK-expressing and ILK-deficient cells, suggesting that ILK is not essential for KGF receptor signaling. In contrast, KGF promoted activation of Rac1 and formation of pseudopodia in ILK-expressing, but not in ILK-deficient cells. Rac1-deficient keratinocytes also showed substantially impaired phagocytic ability, underlining the importance of ILK-dependent Rac1 function for particle engulfment. Finally, cross-modulation of KGF receptors by integrins may be another important element, as integrin β1-deficient keratinocytes also fail to show significant phagocytosis in response to KGF. Thus, we have identified a novel signaling pathway essential for phagocytosis in keratinocytes, which involves ILK-dependent activation of Rac1 in response to KGF, resulting in the formation of pseudopodia and particle uptake.

  18. Galectin-3 modulates the polarized surface delivery of β1-integrin in epithelial cells.

    Science.gov (United States)

    Hönig, Ellena; Ringer, Karina; Dewes, Jenny; von Mach, Tobias; Kamm, Natalia; Kreitzer, Geri; Jacob, Ralf

    2018-05-10

    Epithelial cells require a precise intracellular transport and sorting machinery in order to establish and maintain their polarized architecture. This machinery includes beta-galactoside binding galectins for glycoprotein targeting to the apical membrane. Galectin-3 sorts cargo destined for the apical plasma membrane into vesicular carriers. After delivery of cargo to the apical milieu, galectin-3 recycles back into sorting organelles. We analyzed the role of galectin-3 in the polarized distribution of β1-integrin in MDCK cells. Integrins are located primarily at the basolateral domain of epithelial cells. We demonstrate that a minor pool of β1-integrin interacts with galectin-3 at the apical plasma membrane. Knockdown of galectin-3 decreases apical delivery of β1-integrin. This loss is restored by supplementation with recombinant galectin-3 and galectin-3 overexpression. Our data suggest that galectin-3 targets newly synthesized β1-integrin to the apical membrane and promotes apical delivery of β1-integrin internalized from the basolateral membrane. In parallel, galectin-3 knockout results in a reduction in cell proliferation and an impairment in proper cyst development. Our results suggest that galectin-3 modulates the surface distribution of β1-integrin and affects the morphogenesis of polarized cells. © 2018. Published by The Company of Biologists Ltd.

  19. Multiple integrin-ligand interactions synergize in shear-resistant platelet adhesion at sites of arterial injury in vivo

    DEFF Research Database (Denmark)

    Grüner, Sabine; Prostredna, Miroslava; Schulte, Valerie

    2003-01-01

    by intravital fluorescence microscopy that platelet adhesion and thrombus growth on the exposed ECM of the injured carotid artery is not significantly altered in alpha2-null mice and even in mice with a Cre/loxP-mediated loss of all beta1 integrins on their platelets. In contrast, inhibition of alphaIIbbeta3...... integrin on platelets in wild-type mice blocked aggregate formation and reduced platelet adhesion by 60.0%. Strikingly, alphaIIbbeta3 inhibition had a comparable effect in alpha2-null mice, demonstrating that other receptors mediate shear-resistant adhesion in the absence of functional alpha2beta1...... and alphaIIbbeta3. These were identified to be alpha5beta1 and/or alpha6beta1 as alphaIIbbeta3 inhibition abrogated platelet adhesion in beta1-null mice. We conclude that shear-resistant platelet adhesion on the injured vessel wall in vivo is a highly integrated process involving multiple integrin...

  20. Quantitative and functional analysis of CD69+ T regulatory lymphocytes in patients with periodontal disease.

    Science.gov (United States)

    Vitales-Noyola, Marlen; Martínez-Martínez, Rita; Loyola-Rodríguez, Juan P; Baranda, Lourdes; Niño-Moreno, Perla; González-Amaro, Roberto

    2017-08-01

    Periodontal disease is chronic inflammatory process that affects the attachment structures of the teeth and constitutes a significant cause of tooth loss in adults. Although different bacteria play an important role in the triggering of this condition, the progression and severity of the disease are strongly affected by the host immune response, which is under the control of different immune regulatory mechanisms, including T regulatory (Treg) cells. The aim of this study was to assess the frequency and function of CD69 + Treg lymphocytes in patients with chronic periodontal disease. Peripheral blood samples (n = 33) and gingival tissue (n = 9) were obtained from patients with chronic periodontal disease. Blood samples from 25 healthy individuals were also studied. Levels of CD69 + Treg lymphocytes in peripheral blood and gingival tissue were determined by six-color multiparametric flow cytometry, immunofluorescence, and immunohistochemistry. The immune regulatory function of CD69 + Treg cells was tested by an in vitro assay of inhibition of lymphocyte activation. Percentages of CD69 + Treg cells were significantly higher in the peripheral blood from patients with active periodontal disease compared to healthy controls, and these percentages inversely correlated with the periodontal attachment loss. Increased numbers of these Treg cells were detected in the gingival tissue from active PD patients compared to their peripheral blood. However, the suppressive function of CD69 + Treg cells was significantly diminished in patients with periodontal disease compared to healthy controls. Our data suggest that CD69 + Treg cells seem to be another important piece in the complex immunopathogenesis of periodontal disease. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  1. Association of nutritional status and functional capacity in gastrointestinal cancer patients.

    Science.gov (United States)

    Pérez-Cruz, Elizabeth; Camacho-Limas, Christian Patricio

    To determine the nutritional status and its association with functional capacity in patients with digestive tract cancer. We retrospectively studied all adult patients hospitalized who were diagnosed as having a cancer of the digestive tract. Nutritional status and functional capacity were assessed. Descriptive statistic and odds ratio were used to determine the association in SPSS 14.0. 57 patients were included, 96% had weight loss. Using subjective global assessment (SGA) as a method of screening, 82.5% of the patients were found malnutrition and by biochemical and immunological test 82% and 65% respectively. Functional capacity was assessed by Karnofsky index, finding that 75.5% of the patients have some activity limitation. Results show an association between malnutrition by SGA and limitation in functional capacity (c2 = 1.56; p = 0.212; OR: 2.46; 95% confidence interval [95% CI]: 0.581-10.465). In addition, we observe an association between the total lymphocyte count and limitation in functional capacity (χ2 = 6.94; p = 0.008; OR: 5.23; 95% CI: 1.441-19.025). Malnutrition in patients with digestive tract cancer was associated with limitation in functional capacity. Copyright: © 2017 SecretarÍa de Salud

  2. Histoplasma capsulatum-Induced Cytokine Secretion in Lung Epithelial Cells Is Dependent on Host Integrins, Src-Family Kinase Activation, and Membrane Raft Recruitment.

    Science.gov (United States)

    Maza, Paloma K; Suzuki, Erika

    2016-01-01

    Histoplasma capsulatum var. capsulatum is a dimorphic fungus that causes histoplasmosis, a human systemic mycosis with worldwide distribution. In the present work, we demonstrate that H. capsulatum yeasts are able to induce cytokine secretion by the human lung epithelial cell line A549 in integrin- and Src-family kinase (SFK)-dependent manners. This conclusion is supported by small interfering RNA (siRNA) directed to α3 and α5 integrins, and PP2, an inhibitor of SFK activation. siRNA and PP2 reduced IL-6 and IL-8 secretion in H. capsulatum-infected A549 cell cultures. In addition, α3 and α5 integrins from A549 cells were capable of associating with H. capsulatum yeasts, and this fungus promotes recruitment of these integrins and SFKs to A549 cell membrane rafts. Corroborating this finding, membrane raft disruption with the cholesterol-chelator methyl-β-cyclodextrin reduced the levels of integrins and SFKs in these cell membrane domains. Finally, pretreatment of A549 cells with the cholesterol-binding compound, and also a membrane raft disruptor, filipin, significantly reduced IL-6 and IL-8 levels in A549-H.capsulatum cultures. Taken together, these results indicate that H. capsulatum yeasts induce secretion of IL-6 and IL-8 in human lung epithelial cells by interacting with α3 and α5 integrins, recruiting these integrins to membrane rafts, and promoting SFK activation.

  3. Phoyunnanin E inhibits migration of non-small cell lung cancer cells via suppression of epithelial-to-mesenchymal transition and integrin αv and integrin β3.

    Science.gov (United States)

    Petpiroon, Nareerat; Sritularak, Boonchoo; Chanvorachote, Pithi

    2017-12-29

    The conversion of the epithelial phenotype of cancer cells into cells with a mesenchymal phenotype-so-called epithelial-mesenchymal transition (EMT)-has been shown to enhance the capacity of the cells to disseminate throughout the body. EMT is therefore becoming a potential target for anti-cancer drug discovery. Here, we showed that phoyunnanin E, a compound isolated from Dendrobium venustum, possesses anti-migration activity and addressed its mechanism of action. The cytotoxic and proliferative effects of phoyunnanin E on human non-small cell lung cancer-derived H460, H292, and A549 cells and human keratinocyte HaCaT cells were investigated by MTT assay. The effect of phoyunnanin E on EMT was evaluated by determining the colony formation and EMT markers. The migration and invasion of H460, H292, A549 and HaCaT cells was evaluated by wound healing assay and transwell invasion assay, respectively. EMT markers, integrins and migration-associated proteins were examined by western blot analysis. Phoyunnanin E at the concentrations of 5 and 10 μM, which are non-toxic to H460, H292, A549 and HaCaT cells showed good potential to inhibit the migratory activity of three types of human lung cancer cells. The anti-migration effect of phoyunnanin E was shown to relate to the suppressed EMT phenotypes, including growth in anchorage-independent condition, cell motility, and EMT-specific protein markers (N-cadherin, vimentin, slug, and snail). In addition to EMT suppression, we found that phoyunnanin E treatment with 5 and 10 μM could decrease the cellular level of integrin αv and integrin β3, these integrins are frequently up-regulated in highly metastatic tumor cells. We further characterized the regulatory proteins in cell migration and found that the cells treated with phoyunnanin E exhibited a significantly lower level of phosphorylated focal adhesion kinase (p-FAK) and phosphorylated ATP-dependent tyrosine kinase (p-AKT), and their downstream effectors (including

  4. Cell motility in chronic lymphocytic leukemia: defective Rap1 and alphaLbeta2 activation by chemokine.

    Science.gov (United States)

    Till, Kathleen J; Harris, Robert J; Linford, Andrea; Spiller, David G; Zuzel, Mirko; Cawley, John C

    2008-10-15

    Chemokine-induced activation of alpha4beta1 and alphaLbeta2 integrins (by conformational change and clustering) is required for lymphocyte transendothelial migration (TEM) and entry into lymph nodes. We have previously reported that chemokine-induced TEM is defective in chronic lymphocytic leukemia (CLL) and that this defect is a result of failure of the chemokine to induce polar clustering of alphaLbeta2; engagement of alpha4beta1 and autocrine vascular endothelial growth factor (VEGF) restore clustering and TEM. The aim of the present study was to characterize the nature of this defect in alphaLbeta2 activation and determine how it is corrected. We show here that the alphaLbeta2 of CLL cells is already in variably activated conformations, which are not further altered by chemokine treatment. Importantly, such treatment usually does not cause an increase in the GTP-loading of Rap1, a GTPase central to chemokine-induced activation of integrins. Furthermore, we show that this defect in Rap1 GTP-loading is at the level of the GTPase and is corrected in CLL cells cultured in the absence of exogenous stimuli, suggesting that the defect is the result of in vivo stimulation. Finally, we show that, because Rap1-induced activation of both alpha4beta1 and alphaLbeta2 is defective, autocrine VEGF and chemokine are necessary to activate alpha4beta1 for ligand binding. Subsequently, this binding and both VEGF and chemokine stimulation are all needed for alphaLbeta2 activation for motility and TEM. The present study not only clarifies the nature of the alphaLbeta2 defect of CLL cells but is the first to implicate activation of Rap1 in the pathophysiology of CLL.

  5. Interaction of VLA-5 Molecule With Rheumatoid Articular Cartilage Surface : An Electron Microscopic Evidence of Expression of VLA-5 on Pannus Invading Cells

    OpenAIRE

    Ishikawa, Hitoshi; Hirata, Souichirou; Saura, Ryuuichi; Andoh, Yoshihiro; Mizuno, Kosaku

    1998-01-01

    Pannus is made up mainly of fibroblasts, macrophages and lymphocytes. VLA-5 positive cells are present in the pannus in large numbers. It is likely that the tissue distribution of infiltrated cells derived from post-capillary venules is influenced by the ECM of the pannus and the ability of these cells to interact with the ECM through surface receptor expression. VLA-5 molecules are the predominant (31 integrins expressed by synovial pannus. Since the VLA integrins function as fibronectin rec...

  6. The immunodeficiency of bone marrow-transplanted patients. II. CD8-related suppression by patient lymphocytes of the response of donor lymphocytes to mitogens, antigens, and allogeneic cells

    DEFF Research Database (Denmark)

    Ødum, Niels; Hofmann, B; Jacobsen, N

    1987-01-01

    Lymphocytes from 21 patients sampled 1-6 months after bone marrow transplantation (BMT) were tested for functional suppressor activity against marrow-donor lymphocytes in the lymphocyte transformation test. Suppression of donor responses to allogeneic (i.e. mixed lymphocyte reaction, MLR...

  7. High circulating levels of tumor necrosis factor-alpha in centenarians are not associated with increased production in T lymphocytes

    DEFF Research Database (Denmark)

    Sandmand, Marie; Bruunsgaard, Helle; Kemp, Kåre

    2003-01-01

    BACKGROUND: Aging is characterized by increased inflammatory activity reflected by increased plasma levels of proinflammatory cytokines, concomitant with an altered cytokine profile of T lymphocytes. High plasma levels of tumor necrosis factor (TNF)-alpha are strongly associated with morbidity...... and mortality in elderly humans. However, the cellular source and mechanisms for the increased circulating TNF-alpha levels are unknown. OBJECTIVE: The aim of the present study was to investigate if high plasma levels of TNF-alpha are associated with increased production of TNF-alpha by T lymphocytes in elderly...... humans. METHODS: TNF-alpha production by CD4+ and CD8+ T lymphocytes was measured by flow cytometry following stimulation with phorbol 12-myristate 13-acetate and ionomycin in 28 young controls, 14, 81-year-olds and 25 centenarians. RESULTS: Plasma levels of TNF-alpha increased with increasing age...

  8. Structural basis and kinetics of force-induced conformational changes of an αA domain-containing integrin.

    Directory of Open Access Journals (Sweden)

    Xue Xiang

    Full Text Available Integrin α(Lβ₂ (lymphocyte function-associated antigen, LFA-1 bears force upon binding to its ligand intercellular adhesion molecule 1 (ICAM-1 when a leukocyte adheres to vascular endothelium or an antigen presenting cell (APC during immune responses. The ligand binding propensity of LFA-1 is related to its conformations, which can be regulated by force. Three conformations of the LFA-1 αA domain, determined by the position of its α₇-helix, have been suggested to correspond to three different affinity states for ligand binding.The kinetics of the force-driven transitions between these conformations has not been defined and dynamically coupled to the force-dependent dissociation from ligand. Here we show, by steered molecular dynamics (SMD simulations, that the αA domain was successively transitioned through three distinct conformations upon pulling the C-terminus of its α₇-helix. Based on these sequential transitions, we have constructed a mathematical model to describe the coupling between the αA domain conformational changes of LFA-1 and its dissociation from ICAM-1 under force. Using this model to analyze the published data on the force-induced dissociation of single LFA-1/ICAM-1 bonds, we estimated the force-dependent kinetic rates of interstate transition from the short-lived to intermediate-lived and from intermediate-lived to long-lived states. Interestingly, force increased these transition rates; hence activation of LFA-1 was accelerated by pulling it via an engaged ICAM-1.Our study defines the structural basis for mechanical regulation of the kinetics of LFA-1 αA domain conformational changes and relates these simulation results to experimental data of force-induced dissociation of single LFA-1/ICAM-1 bonds by a new mathematical model, thus provided detailed structural and kinetic characterizations for force-stabilization of LFA-1/ICAM-1 interaction.

  9. Effect of PF-00547659 on Central Nervous System Immune Surveillance and Circulating beta 7+T Cells in Crohn's Disease: Report of the TOSCA Study

    NARCIS (Netherlands)

    D'Haens, Geert; Vermeire, Séverine; Vogelsang, Harald; Allez, Matthieu; Desreumaux, Pierre; van Gossum, Andre; Sandborn, William J.; Baumgart, Daniel C.; Ransohoff, Richard M.; Comer, Gail M.; Ahmad, Alaa; Cataldi, Fabio; Cheng, John; Clare, Robert; Gorelick, Kenneth J.; Kaminski, Annamarie; Pradhan, Vivek; Rivers, Sunday; Sikpi, Matthew O.; Zhang, Yanhua; Hassan-Zahraee, Mina; Reinisch, Walter; Stuve, Olaf

    2018-01-01

    Background and Aims: Progressive multifocal leukoencephalopathy [PML], a brain infection associated with anti-integrin drugs that inhibit lymphocyte translocation from bloodstream to tissue, can be fatal. Decreased central nervous system [CNS] immune surveillance leading to this infection has been

  10. Lymphocyte-platelet crosstalk in Graves' disease.

    Science.gov (United States)

    Kuznik, Boris I; Vitkovsky, Yuri A; Gvozdeva, Olga V; Solpov, Alexey V; Magen, Eli

    2014-03-01

    Platelets can modulate lymphocytes' role in the pathophysiology of thyroid autoimmune diseases. The present study was performed to clarify the status of platelet-lymphocyte subpopulations aggregation in circulating blood in patients with Graves' disease (GD). One hundred and fifty patients with GD (GD group) and 45 hyperthyroid patients with toxic multinodular goiter (TMG group) were recruited in the study. Control group consisted 150 healthy subjects. Immunophenotyping of lymphocytes was performed by flow cytometry. Detection of lymphocyte-platelet aggregates (LPAs) was done using light microscope after Ficoll-gradient centrifugation. The group of GD patients exhibited reduced CD8 lymphocyte and higher CD19 cell counts compared with TMG group and healthy controls. A greater number of activated CD3, HLA-DR+ lymphocytes were observed in GD than in TMG group and control group. GD group was characterized by lower blood platelet count (232 ± 89 × 10 cells/µL) than TMG group (251 ± 97 × 10 cells/µL; P TMG group (116 ± 67/µL, P < 0.005) and control group (104 ± 58 /µL; P < 0.001). GD is associated with higher levels of activated lymphocytes and lymphocyte-platelet aggregates.

  11. Alterations in circulating T-cell lymphocyte populations in children with obstructive sleep apnea.

    Science.gov (United States)

    Tan, Hui-Leng; Gozal, David; Wang, Yang; Bandla, Hari P R; Bhattacharjee, Rakesh; Kulkarni, Richa; Kheirandish-Gozal, Leila

    2013-06-01

    Changes in lymphocyte phenotype and functionality have been described in adult patients with obstructive sleep apnea (OSA). We hypothesized that OSA is associated with T lymphocyte alterations in children, particularly in T regulatory lymphocytes (T regs), and aimed to characterize circulating T lymphocyte subsets in children with OSA. Cross-sectional. Kosair Children's Hospital (Louisville, KY, USA) and Comer Children's Hospital (Chicago, IL, USA). Consecutively recruited children being evaluated for habitual snoring. N/A. Overnight polysomnography (PSG) was performed and a fasting blood sample was obtained from the patients. Flow cytometry was performed on peripheral blood mononuclear cells stained for CD3, CD4, CD8, CD25, FOXP3, interleukin-4 (IL-4), interferon-γ (IFN-γ), and IL-17. Patients were divided into three groups based on their PSG: controls (apnea-hypopnea indices [AHI] hTST), moderate-severe OSA (AHI ≥ 5/h TST). The percentage of CD4+ and T reg lymphocytes differed across groups. Children with moderate-severe OSA had significantly reduced T reg than control children (median [interquartile range] 4.8 [3.8-5.7% CD4+] versus 7.8 [7.0-9.2% CD4+]; P < 0.001). There were also significant differences in the percentage of T helper 1 (Th1) lymphocytes and in Th1:Th2 ratios between groups. Children with moderate-severe OSA had increased Th1 cells (P = 0.001) and Th1:Th2 ratios (P = 0.0026) compared with children with mild OSA and control children. Associations between AHI and T reg (P = 0.0003; r = -0.46), CD4+ lymphocytes (P = 0.0047; r = -0.37), and Th1:Th2 ratios (P = 0.0009; r = 0.43) emerged. In addition, the percentage of T reg was inversely correlated with Th1:Th2 ratios (P = 0.029; r = -0.29). Pediatric OSA is associated with reduced T reg population and altered Th1:Th2 balance toward Th1 predominance, suggesting a shift to a proinflammatory state. The changes in lymphocytic phenotypes associated with OSA may contribute to the variance in systemic

  12. Divergent effects of norepinephrine, dopamine and substance P on the activation, differentiation and effector functions of human cytotoxic T lymphocytes

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    Niggemann Bernd

    2009-12-01

    Full Text Available Abstract Background Neurotransmitters are important regulators of the immune system, with very distinct and varying effects on different leukocyte subsets. So far little is known about the impact of signals mediated by neurotransmitters on the function of CD8+ T lymphocytes. Therefore, we investigated the influence of norepinephrine, dopamine and substance P on the key tasks of CD8+ T lymphocytes: activation, migration, extravasation and cytotoxicity. Results The activation of naïve CD8+ T lymphocytes by CD3/CD28 cross-linking was inhibited by norepinephrine and dopamine, which was caused by a downregulation of interleukin (IL-2 expression via Erk1/2 and NF-κB inhibition. Furthermore, all of the investigated neurotransmitters increased the spontaneous migratory activity of naïve CD8+ T lymphocytes with dopamine being the strongest inducer. In contrast, activated CD8+ T lymphocytes showed a reduced migratory activity in the presence of norepinephrine and substance P. With regard to extravasation we found norepinephrine to induce adhesion of activated CD8+ T cells: norepinephrine increased the interleukin-8 release from endothelium, which in turn had effect on the activated CXCR1+ CD8+ T cells. At last, release of cytotoxic granules from activated cells in response to CD3 cross-linking was not influenced by any of the investigated neurotransmitters, as we have analyzed by measuring the β-hexosamidase release. Conclusion Neurotransmitters are specific modulators of CD8+ T lymphocytes not by inducing any new functions, but by fine-tuning their key tasks. The effect can be either stimulatory or suppressive depending on the activation status of the cells.

  13. 2SNP heritability and effects of genetic variants for neutrophil-to-lymphocyte and platelet-to-lymphocyte ratio

    NARCIS (Netherlands)

    Lin, Bochao Danae; Carnero-Montoro, Elena; Bell, Jordana T; Boomsma, Dorret I; de Geus, Eco J; Jansen, Rick; Kluft, Cornelis; Mangino, Massimo; Penninx, Brenda; Spector, Tim D; Willemsen, Gonneke; Hottenga, Jouke-Jan

    2017-01-01

    Neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) are important biomarkers for disease development and progression. To gain insight into the genetic causes of variance in NLR and PLR in the general population, we conducted genome-wide association (GWA) analyses and

  14. Lymphocyte gene expression signatures from patients and mouse models of hereditary hemochromatosis reveal a function of HFE as a negative regulator of CD8+ T-lymphocyte activation and differentiation in vivo.

    Science.gov (United States)

    Costa, Mónica; Cruz, Eugénia; Oliveira, Susana; Benes, Vladimir; Ivacevic, Tomi; Silva, Maria João; Vieira, Inês; Dias, Francisco; Fonseca, Sónia; Gonçalves, Marta; Lima, Margarida; Leitão, Catarina; Muckenthaler, Martina U; Pinto, Jorge; Porto, Graça

    2015-01-01

    Abnormally low CD8+ T-lymphocyte numbers is characteristic of some patients with hereditary hemochromatosis (HH), a MHC-linked disorder of iron overload. Both environmental and genetic components are known to influence CD8+ T-lymphocyte homeostasis but the role of the HH associated protein HFE is still insufficiently understood. Genome-wide expression profiling was performed in peripheral blood CD8+ T lymphocytes from HH patients selected according to CD8+ T-lymphocyte numbers and from Hfe-/- mice maintained either under normal or high iron diet conditions. In addition, T-lymphocyte apoptosis and cell cycle progression were analyzed by flow cytometry in HH patients. HH patients with low CD8+ T-lymphocyte numbers show a differential expression of genes related to lymphocyte differentiation and maturation namely CCR7, LEF1, ACTN1, NAA50, P2RY8 and FOSL2, whose expression correlates with the relative proportions of naïve, central and effector memory subsets. In addition, expression levels of LEF1 and P2RY8 in memory cells as well as the proportions of CD8+ T cells in G2/M cell cycle phase are significantly different in HH patients compared to controls. Hfe-/- mice do not show alterations in CD8+ T-lymphocyte numbers but differential gene response patterns. We found an increased expression of S100a8 and S100a9 that is most pronounced in high iron diet conditions. Similarly, CD8+ T lymphocytes from HH patients display higher S100a9 expression both at the mRNA and protein level. Altogether, our results support a role for HFE as a negative regulator of CD8+ T-lymphocyte activation. While the activation markers S100a8 and S100a9 are strongly increased in CD8+ T cells from both, Hfe-/- mice and HH patients, a differential profile of genes related to differentiation/maturation of CD8+ T memory cells is evident in HH patients only. This supports the notion that HFE contributes, at least in part, to the generation of low peripheral blood CD8+ T lymphocytes in HH.

  15. Saccharomyces boulardii improves intestinal cell restitution through activation of the α2β1 integrin collagen receptor.

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    Alexandra Canonici

    Full Text Available Intestinal epithelial cell damage is frequently seen in the mucosal lesions of inflammatory bowel diseases such as ulcerative colitis or Crohn's disease. Complete remission of these diseases requires both the cessation of inflammation and the migration of enterocytes to repair the damaged epithelium. Lyophilized Saccharomyces boulardii (Sb, Biocodex is a nonpathogenic yeast widely used as a therapeutic agent for the treatment and prevention of diarrhea and other gastrointestinal disorders. In this study, we determined whether Sb could accelerate enterocyte migration. Cell migration was determined in Sb force-fed C57BL6J mice and in an in vitro wound model. The impact on α2β1 integrin activity was assessed using adhesion assays and the analysis of α2β1 mediated signaling pathways both in vitro and in vivo. We demonstrated that Sb secretes compounds that enhance the migration of enterocytes independently of cell proliferation. This enhanced migration was associated with the ability of Sb to favor cell-extracellular matrix interaction. Indeed, the yeast activates α2β1 integrin collagen receptors. This leads to an increase in tyrosine phosphorylation of cytoplasmic molecules, including focal adhesion kinase and paxillin, involved in the integrin signaling pathway. These changes are associated with the reorganization of focal adhesion structures. In conclusion Sb secretes motogenic factors that enhance cell restitution through the dynamic regulation of α2β1 integrin activity. This could be of major importance in the development of novel therapies targeting diseases characterized by severe mucosal injury, such as inflammatory and infectious bowel diseases.

  16. Multiple roles of integrin-linked kinase in epidermal development, maturation and pigmentation revealed by molecular profiling.

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    David Judah

    Full Text Available Integrin-linked kinase (ILK is an important scaffold protein that mediates a variety of cellular responses to integrin stimulation by extracellular matrix proteins. Mice with epidermis-restricted inactivation of the Ilk gene exhibit pleiotropic phenotypic defects, including impaired hair follicle morphogenesis, reduced epidermal adhesion to the basement membrane, compromised epidermal integrity, as well as wasting and failure to thrive leading to perinatal death. To better understand the underlying molecular mechanisms that cause such a broad range of alterations, we investigated the impact of Ilk gene inactivation on the epidermis transcriptome. Microarray analysis showed over 700 differentially regulated mRNAs encoding proteins involved in multiple aspects of epidermal function, including keratinocyte differentiation and barrier formation, inflammation, regeneration after injury, and fundamental epidermal developmental pathways. These studies also revealed potential effects on genes not previously implicated in ILK functions, including those important for melanocyte and melanoblast development and function, regulation of cytoskeletal dynamics, and homeobox genes. This study shows that ILK is a critical regulator of multiple aspects of epidermal function and homeostasis, and reveals the previously unreported involvement of ILK not only in epidermal differentiation and barrier formation, but also in melanocyte genesis and function.

  17. Multiple roles of integrin-linked kinase in epidermal development, maturation and pigmentation revealed by molecular profiling.

    Science.gov (United States)

    Judah, David; Rudkouskaya, Alena; Wilson, Ryan; Carter, David E; Dagnino, Lina

    2012-01-01

    Integrin-linked kinase (ILK) is an important scaffold protein that mediates a variety of cellular responses to integrin stimulation by extracellular matrix proteins. Mice with epidermis-restricted inactivation of the Ilk gene exhibit pleiotropic phenotypic defects, including impaired hair follicle morphogenesis, reduced epidermal adhesion to the basement membrane, compromised epidermal integrity, as well as wasting and failure to thrive leading to perinatal death. To better understand the underlying molecular mechanisms that cause such a broad range of alterations, we investigated the impact of Ilk gene inactivation on the epidermis transcriptome. Microarray analysis showed over 700 differentially regulated mRNAs encoding proteins involved in multiple aspects of epidermal function, including keratinocyte differentiation and barrier formation, inflammation, regeneration after injury, and fundamental epidermal developmental pathways. These studies also revealed potential effects on genes not previously implicated in ILK functions, including those important for melanocyte and melanoblast development and function, regulation of cytoskeletal dynamics, and homeobox genes. This study shows that ILK is a critical regulator of multiple aspects of epidermal function and homeostasis, and reveals the previously unreported involvement of ILK not only in epidermal differentiation and barrier formation, but also in melanocyte genesis and function.

  18. Depression of T lymphocyte function in chimpanzees receiving thymectomy and irradiation. [X Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Gilbertsen, R.B.; Metzgar, R.S.

    1978-03-01

    In studies analogous to those in which the thymus dependency of immune functions in murine systems was determined, three chimpanzees were thymectomized, splenectomized, exposed to lethal doses of whole body x-irradiation with limited bone marrow shielding, and subsequently evaluated for lymphocyte markers and functions over a period of years. In the oldest animal studied (Irena, 7.2 years at surgery), the percentage of peripheral blood T cells decreased to about 60% of control values and remained at that level for approximately 1/sup 1///sub 2/ years before returning to normal. In the two youngest chimpanzees T cell rosette values dropped to 15 to 40% of control values after irradiation. T cell percentages in one of these young chimpanzees returned to about 75% of the controls 2/sup 1///sub 2/ years after x-irradiation. Phytohemagglutinin and concanavalin A mitogen responses were less affected in the oldest chimpanzee. However, even in the oldest animal, the responses to phytohemagglutinin and concanavalin A began to show a gradual and consistent decline 1/sup 1///sub 2/ years after irradiation. Mixed leukocyte culture responsiveness was most affected by the experimental procedures, being greatly reduced in all three chimpanzees during varying time intervals. In general, the effects of the experimental procedures used to produce T cell deficiencies varied with the age of the chimpanzee at surgery, the time after irradiation when the animal was tested, and the lymphocyte marker or function studied.

  19. Chemokines, lymphocytes, and HIV

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    Farber J.M.

    1998-01-01

    Full Text Available Chemokines are members of a family of more than 30 human cytokines whose best-described activities are as chemotactic factors for leukocytes and that are presumed to be important in leukocyte recruitment and trafficking. While many chemokines can act on lymphocytes, the roles of chemokines and their receptors in lymphocyte biology are poorly understood. The recent discoveries that chemokines can suppress infection by HIV-1 and that chemokine receptors serve, along with CD4, as obligate co-receptors for HIV-1 entry have lent urgency to studies on the relationships between chemokines and lymphocytes. My laboratory has characterized Mig and Crg-2/IP-10, chemokines that are induced by IFN-g and that specifically target lymphocytes, particularly activated T cells. We have demonstrated that the genes for these chemokines are widely expressed during experimental infections in mice with protozoan and viral pathogens, but that the patterns of mig and crg-2 expression differed, suggesting non-redundant roles in vivo. Our related studies to identify new chemokine receptors from activated lymphocytes resulted in the cloning of STRL22 and STRL33. We and others have shown that STRL22 is a receptor for the CC chemokine MIP-3a, and STRL22 has been re-named CCR6. Although STRL33 remains an orphan receptor, we have shown that it can function as a co-receptor for HIV-1 envelope glycoproteins, and that it is active with a broader range of HIV-1 envelope glycoproteins than the major co-receptors described to date. The ability of STRL33 to function with a wide variety of envelope glycoproteins may become particularly important if therapies are instituted to block other specific co-receptors. We presume that investigations into the roles of chemokines and their receptors in lymphocyte biology will provide information important for understanding the pathogenesis of AIDS and for manipulating immune and inflammatory responses for clinical benefit

  20. Stress-Induced In Vivo Recruitment of Human Cytotoxic Natural Killer Cells Favors Subsets with Distinct Receptor Profiles and Associates with Increased Epinephrine Levels.

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    Marc B Bigler

    Full Text Available Acute stress drives a 'high-alert' response in the immune system. Psychoactive drugs induce distinct stress hormone profiles, offering a sought-after opportunity to dissect the in vivo immunological effects of acute stress in humans.3,4-methylenedioxymethamphetamine (MDMA, methylphenidate (MPH, or both, were administered to healthy volunteers in a randomized, double-blind, placebo-controlled crossover-study. Lymphocyte subset frequencies, natural killer (NK cell immune-phenotypes, and changes in effector function were assessed, and linked to stress hormone levels and expression of CD62L, CX3CR1, CD18, and stress hormone receptors on NK cells.MDMA/MPH > MDMA > MPH robustly induced an epinephrine-dominant stress response. Immunologically, rapid redistribution of peripheral blood lymphocyte-subsets towards phenotypically mature NK cells occurred. NK cytotoxicity was unaltered, but they expressed slightly reduced levels of the activating receptor NKG2D. Preferential circulation of mature NK cells was associated with high epinephrine receptor expression among this subset, as well as expression of integrin ligands previously linked to epinephrine-induced endothelial detachment.The acute epinephrine-induced stress response was characterized by rapid accumulation of mature and functional NK cells in the peripheral circulation. This is in line with studies using other acute stressors and supports the role of the acute stress response in rapidly mobilizing the innate immune system to counteract incoming threats.

  1. AMP-activated protein kinase regulates lymphocyte responses to metabolic stress but is largely dispensable for immune cell development and function.

    Science.gov (United States)

    Mayer, Alice; Denanglaire, Sébastien; Viollet, Benoit; Leo, Oberdan; Andris, Fabienne

    2008-04-01

    AMP-activated protein kinase (AMPK), a phylogenetically conserved serine/threonine protein kinase, represents an energy sensor able to adapt cellular metabolism in response to nutritional environmental variations. TCR stimulation activates AMPK, a regulatory event that is known to stimulate ATP-producing processes, possibly in anticipation of the increased energetic needs associated with cell division and expression of effector function. Taking advantage of the selective expression of the AMPKalpha1 catalytic subunit in lymphoid cells, we have analyzed the in vitro and in vivo capacity of lymphocytes lacking AMPK activity (AMPKalpha1-KO cells) to respond to metabolic stress and to initiate and sustain an immune response. AMPKalpha1-KO cells displayed increasing sensitivity to energetic stress in vitro, and were found unable to maintain adequate ATP levels in response to ATP synthase inhibition. These cells were, however, able to respond to antigen stimulation in vitro, as shown by optimal proliferation and cytokine production. Similarly, AMPKalpha1-KO mice were fully immunocompetent in vivo and displayed normal cell proliferation, humoral, cytotoxic and delayed-type hypersensitivity (DTH) responses following antigen injection. In conclusion, AMPK represents an important enzyme allowing lymphocytes to resist a mild energy crisis in vitro, but is largely dispensable for activation and expression of effector function in response to antigen stimulation.

  2. Effect of radiotherapy on lymphocyte cytotoxicity in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Wasserman, J; Melen, B [Central Microbiological Laboratory, Stockholm County Council (Sweden); Blomgren, H; Glas, U; Perlmann, P

    1975-11-01

    The cytotoxic functions of highly purified blood lymphocytes from patients with breast cancer were studied before and after radiotherapy. Addition of PHA or of rabbit antibodies to target cells (chicken erythrocytes) were chosen as two means of inducing lymphocyte cytotoxicity in vitro. The proportion of T and non-T lymphocytes was determined by means of E and EAC rosette tests. The antibody-induced cytotoxicity of lymphocytes decreased following radiotherapy while that mediated by PHA remained unchanged. There was some reduction in the percentage of EAC rosette-forming cells. These results, as well as earlier observations, suggest that the decrease in the peripheral blood of the proportion of lymphocytes with receptors for activated complement is responsible for changes in the antibody-mediated lymphocyte cytotoxicity.

  3. PI3-kinase γ promotes Rap1a-mediated activation of myeloid cell integrin α4β1, leading to tumor inflammation and growth.

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    Michael C Schmid

    Full Text Available Tumor inflammation, the recruitment of myeloid lineage cells into the tumor microenvironment, promotes angiogenesis, immunosuppression and metastasis. CD11b+Gr1lo monocytic lineage cells and CD11b+Gr1hi granulocytic lineage cells are recruited from the circulation by tumor-derived chemoattractants, which stimulate PI3-kinase γ (PI3Kγ-mediated integrin α4 activation and extravasation. We show here that PI3Kγ activates PLCγ, leading to RasGrp/CalDAG-GEF-I&II mediated, Rap1a-dependent activation of integrin α4β1, extravasation of monocytes and granulocytes, and inflammation-associated tumor progression. Genetic depletion of PLCγ, CalDAG-GEFI or II, Rap1a, or the Rap1 effector RIAM was sufficient to prevent integrin α4 activation by chemoattractants or activated PI3Kγ (p110γCAAX, while activated Rap (RapV12 promoted constitutive integrin activation and cell adhesion that could only be blocked by inhibition of RIAM or integrin α4β1. Similar to blockade of PI3Kγ or integrin α4β1, blockade of Rap1a suppressed both the recruitment of monocytes and granulocytes to tumors and tumor progression. These results demonstrate critical roles for a PI3Kγ-Rap1a-dependent pathway in integrin activation during tumor inflammation and suggest novel avenues for cancer therapy.

  4. T-lymphocyte dependency of B-lymphocyte blastogenic response to phytomitogens

    International Nuclear Information System (INIS)

    Han, T.; Dadey, B.

    1978-01-01

    Human peripheral blood T and B lymphocytes were separated by a method based on the stable rosette formation of T lymphocytes with neuraminidase-treated sheep erythrocytes, followed by centrifugation over a Ficoll-Hypaque gradient. Monocytes were isolated from the T-depleted B lymphocyte preparation by allowing the monocytes to ingest iron particles and by subsequent centrifugation over a Ficoll-Hypaque gradient. The T lymphocytes responded extremely well to PHA and very well to PWM, while the B lymphocytes were unresponsive to either PHA or PWM. However, when the B lymphocytes were cultured together with irradiated autologous or allogeneic T lymphocytes (1 : 1,1:2 or 1 : 4 ratio), both PHA and PWM became mitogenic to B lymphocytes. Irradiated T lymphocytes alone did not respond to either PHA or PWM, indicating that the 3 H-thymidine incorporation seen in the mixed-cell culture was due to the activation of unirradiated B lymphocytes. The B lymphocytes failed to respond to these phytomitogens in the presence of lower concentrations of irradiated T lymphocytes. The monocytes were found to be incapable of helping the B lymphocytes to respond to PHA or PWM. (author)

  5. Oxidized lipids enhance RANKL production by T lymphocytes: implications for lipid-induced bone loss.

    Science.gov (United States)

    Graham, Lucia S; Parhami, Farhad; Tintut, Yin; Kitchen, Christina M R; Demer, Linda L; Effros, Rita B

    2009-11-01

    Osteoporosis is a systemic disease that is associated with increased morbidity, mortality and health care costs. Whereas osteoclasts and osteoblasts are the main regulators of bone homeostasis, recent studies underscore a key role for the immune system, particularly via activation-induced T lymphocyte production of receptor activator of NFkappaB ligand (RANKL). Well-documented as a mediator of T lymphocyte/dendritic cell interactions, RANKL also stimulates the maturation and activation of bone-resorbing osteoclasts. Given that lipid oxidation products mediate inflammatory and metabolic disorders such as osteoporosis and atherosclerosis, and since oxidized lipids affect several T lymphocyte functions, we hypothesized that RANKL production might also be subject to modulation by oxidized lipids. Here, we show that short term exposure of both unstimulated and activated human T lymphocytes to minimally oxidized low density lipoprotein (LDL), but not native LDL, significantly enhances RANKL production and promotes expression of the lectin-like oxidized LDL receptor-1 (LOX-1). The effect, which is also observed with 8-iso-Prostaglandin E2, an inflammatory isoprostane produced by lipid peroxidation, is mediated via the NFkappaB pathway, and involves increased RANKL mRNA expression. The link between oxidized lipids and T lymphocytes is further reinforced by analysis of hyperlipidemic mice, in which bone loss is associated with increased RANKL mRNA in T lymphocytes and elevated RANKL serum levels. Our results suggest a novel pathway by which T lymphocytes contribute to bone changes, namely, via oxidized lipid enhancement of RANKL production. These findings may help elucidate clinical associations between cardiovascular disease and decreased bone mass, and may also lead to new immune-based approaches to osteoporosis.

  6. Response of human lymphocytes to low gamma ray doses

    International Nuclear Information System (INIS)

    Vega Carrillo, HR; Banuelos Valenzuela, R; Manzanares Acuna, E; Sanchez-Rodriguez, S.H

    2001-01-01

    Radiation and non-radiation workers lymphocytes were exposed to a low strength gamma-ray field to determine heat shock protein expression in function of radiation dose. Protein identification was carried out using mAb raised against Hsp25, Hsp60, Hsp70 and Hsp90; from these, only Hsp70 protein was detected before and after lymphocyte irradiation. In all cases, an increasing trend of relative amounts of Hsp70 in function to irradiation time was observed. After 70.5 mGy gamma-ray dose, radiation worker's lymphocytes expressed more Hsp70 protein, than non-radiation workers' lymphocytes, indicating a larger tolerance to gamma rays (gamma tolerance), due to an adaptation process developed by their labor condition (Au)

  7. Integrin αvβ1 Modulation Affects Subtype B Avian Metapneumovirus Fusion Protein-mediated Cell-Cell Fusion and Virus Infection.

    Science.gov (United States)

    Yun, Bing-Ling; Guan, Xiao-Lu; Liu, Yong-Zhen; Zhang, Yao; Wang, Yong-Qiang; Qi, Xiao-Le; Cui, Hong-Yu; Liu, Chang-Jun; Zhang, Yan-Ping; Gao, Hong-Lei; Gao, Li; Li, Kai; Gao, Yu-Long; Wang, Xiao-Mei

    2016-07-08

    Avian metapneumovirus (aMPV) fusion (F) protein mediates virus-cell membrane fusion to initiate viral infection, which requires F protein binding to its receptor(s) on the host cell surface. However, the receptor(s) for aMPV F protein is still not identified. All known subtype B aMPV (aMPV/B) F proteins contain a conserved Arg-Asp-Asp (RDD) motif, suggesting that the aMPV/B F protein may mediate membrane fusion via the binding of RDD to integrin. When blocked with integrin-specific peptides, aMPV/B F protein fusogenicity and viral replication were significantly reduced. Specifically we identified integrin αv and/or β1-mediated F protein fusogenicity and viral replication using antibody blocking, small interfering RNAs (siRNAs) knockdown, and overexpression. Additionally, overexpression of integrin αv and β1 in aMPV/B non-permissive cells conferred aMPV/B F protein binding and aMPV/B infection. When RDD was altered to RAE (Arg-Ala-Glu), aMPV/B F protein binding and fusogenic activity were profoundly impaired. These results suggest that integrin αvβ1 is a functional receptor for aMPV/B F protein-mediated membrane fusion and virus infection, which will provide new insights on the fusogenic mechanism and pathogenesis of aMPV. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  8. Integrin αvβ1 Modulation Affects Subtype B Avian Metapneumovirus Fusion Protein-mediated Cell-Cell Fusion and Virus Infection*

    Science.gov (United States)

    Yun, Bing-Ling; Guan, Xiao-Lu; Liu, Yong-Zhen; Zhang, Yao; Wang, Yong-Qiang; Qi, Xiao-Le; Cui, Hong-Yu; Liu, Chang-Jun; Zhang, Yan-Ping; Gao, Hong-Lei; Gao, Li; Li, Kai; Gao, Yu-Long; Wang, Xiao-Mei

    2016-01-01

    Avian metapneumovirus (aMPV) fusion (F) protein mediates virus-cell membrane fusion to initiate viral infection, which requires F protein binding to its receptor(s) on the host cell surface. However, the receptor(s) for aMPV F protein is still not identified. All known subtype B aMPV (aMPV/B) F proteins contain a conserved Arg-Asp-Asp (RDD) motif, suggesting that the aMPV/B F protein may mediate membrane fusion via the binding of RDD to integrin. When blocked with integrin-specific peptides, aMPV/B F protein fusogenicity and viral replication were significantly reduced. Specifically we identified integrin αv and/or β1-mediated F protein fusogenicity and viral replication using antibody blocking, small interfering RNAs (siRNAs) knockdown, and overexpression. Additionally, overexpression of integrin αv and β1 in aMPV/B non-permissive cells conferred aMPV/B F protein binding and aMPV/B infection. When RDD was altered to RAE (Arg-Ala-Glu), aMPV/B F protein binding and fusogenic activity were profoundly impaired. These results suggest that integrin αvβ1 is a functional receptor for aMPV/B F protein-mediated membrane fusion and virus infection, which will provide new insights on the fusogenic mechanism and pathogenesis of aMPV. PMID:27226547

  9. Chromosome aberrations in T lymphocytes carrying adult T-cell leukemia-associated antigens (ATLA) from healthy adults.

    Science.gov (United States)

    Fukuhara, S; Hinuma, Y; Gotoh, Y I; Uchino, H

    1983-01-01

    Chromosomes were studied in cultured T lymphocytes carrying adult T-cell leukemia-associated antigens (ATLA) that were obtained from five Japanese anti-ATLA seropositive healthy adults. Chromosomally abnormal cells were observed in three of the five healthy adults, and these cells were clonal in two subjects. All cells examined in one subject had rearrangements of chromosome nos. 7 and 14. Clonal cells from the second had a minute chromosome of unknown origin. A few cells in the third had nonclonal rearrangements of chromosomes. Thus, ATLA-positive T lymphocytes in some anti-ATLA seropositive healthy people have chromosome aberrations.

  10. Polyvalent integrin antagonist-decorated superparamagnetic iron oxide nanoparticles for triggering apoptosis in human leukemia cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Say, R Latin-Small-Letter-Dotless-I dvan, E-mail: rsay@anadolu.edu.tr [Anadolu Universitesi, Kimya Boeluemue, Fen Fakueltesi (Turkey); Yazar, Suzan [Sanovel Pharmaceutical Company (Turkey); Ugur, Alper; Huer, Deniz [Anadolu Universitesi, Kimya Boeluemue, Fen Fakueltesi (Turkey); Denizli, Adil [Hacettepe University, Department of Chemistry (Turkey); Ersoez, Arzu [Anadolu Universitesi, Kimya Boeluemue, Fen Fakueltesi (Turkey)

    2013-01-15

    Integrin family members are the main mediators of cell adhesion to the extracellular matrix and active as intra- and extracellular signaling molecules in a variety of processes. They bind to their ligands by interacting with short amino acid sequences, that is, RGD (arginine-glycine-aspartic acid) sequence. RGD sequences have been used to enhance cell binding to artificial surfaces, so RGD mimics have been used to block integrin binding to its ligand. Integrin-ligand interactions are dependent on divalent cations, and Mg{sup 2+} provide higher-affinity binding to ligand for many integrins. In this study, we have designed new integrin antagonists using methacryloyl amidoaspartic acid (MAASP) monomer-conjugated silanized super paramagnetic iron oxide nanoparticles (SPIONs, the size of the nanoparticles was verified with an average size of 32.6 nm) and poly(MAASP-co-EDMA) shell-decorated silanized SPIONs. Several mechanisms have been proposed to describe uptake of modified SPIONs into the cells, including receptor-mediated endocytosis. Our aim is to bind these modified SPIONs to the integrin-mediated aspartic acid ends of MAASP monomers and block integrin binding to their ligand.

  11. Sarcospan integration into laminin-binding adhesion complexes that ameliorate muscular dystrophy requires utrophin and α7 integrin

    Science.gov (United States)

    Marshall, Jamie L.; Oh, Jennifer; Chou, Eric; Lee, Joy A.; Holmberg, Johan; Burkin, Dean J.; Crosbie-Watson, Rachelle H.

    2015-01-01

    Duchenne muscular dystrophy (DMD) is caused by mutations in the dystrophin gene that result in loss of the dystrophin–glycoprotein complex, a laminin receptor that connects the myofiber to its surrounding extracellular matrix. Utrophin, a dystrophin ortholog that is normally localized to the neuromuscular junction, is naturally upregulated in DMD muscle, which partially compensates for the loss of dystrophin. Transgenic overexpression of utrophin causes broad sarcolemma localization of utrophin, restoration of laminin binding and amelioration of disease in the mdx mouse model of DMD. We previously demonstrated that overexpression of sarcospan, a dystrophin- and utrophin-binding protein, ameliorates mdx muscular dystrophy. Sarcospan boosts levels of utrophin to therapeutic levels at the sarcolemma, where attachment to laminin is restored. However, understanding the compensatory mechanism is complicated by concomitant upregulation of α7β1 integrin, which also binds laminin. Similar to the effects of utrophin, transgenic overexpression of α7 integrin prevents DMD disease in mice and is accompanied by increased abundance of utrophin around the extra-synaptic sarcolemma. In order to investigate the mechanisms underlying sarcospan ‘rescue’ of muscular dystrophy, we created double-knockout mice to test the contributions of utrophin or α7 integrin. We show that sarcospan-mediated amelioration of muscular dystrophy in DMD mice is dependent on the presence of both utrophin and α7β1 integrin, even when they are individually expressed at therapeutic levels. Furthermore, we found that association of sarcospan into laminin-binding complexes is dependent on utrophin and α7β1 integrin. PMID:25504048

  12. The integrin alphav beta3 increases cellular stiffness and cytoskeletal remodeling dynamics to facilitate cancer cell invasion

    Science.gov (United States)

    Mierke, Claudia Tanja

    2013-01-01

    The process of cancer cell invasion through the extracellular matrix (ECM) of connective tissue plays a prominent role in tumor progression and is based fundamentally on biomechanics. Cancer cell invasion usually requires cell adhesion to the ECM through the cell-matrix adhesion receptors integrins. The expression of the αvβ3 integrin is increased in several tumor types and is consistently associated with increased metastasis formation in patients. The hypothesis was that the αvβ3 integrin expression increases the invasiveness of cancer cells through increased cellular stiffness, and increased cytoskeletal remodeling dynamics. Here, the invasion of cancer cells with different αvβ3 integrin expression levels into dense three-dimensional (3D) ECMs has been studied. Using a cell sorter, two subcell lines expressing either high or low amounts of αvβ3 integrins (αvβ3high or αvβ3low cells, respectively) have been isolated from parental MDA-MB-231 breast cancer cells. αvβ3high cells showed a threefold increased cell invasion compared to αvβ3low cells. Similar results were obtained for A375 melanoma, 786-O kidney and T24 bladder carcinoma cells, and cells in which the β3 integrin subunit was knocked down using specific siRNA. To investigate whether contractile forces are essential for αvβ3 integrin-mediated increased cellular stiffness and subsequently enhanced cancer cell invasion, invasion assays were performed in the presence of myosin light chain kinase inhibitor ML-7 and Rho kinase inhibitor Y27632. Indeed, cancer cell invasiveness was reduced after addition of ML-7 and Y27632 in αvβ3high cells but not in αvβ3low cells. Moreover, after addition of the contractility enhancer calyculin A, an increase in pre-stress in αvβ3low cells was observed, which enhanced cellular invasiveness. In addition, inhibition of the Src kinase, STAT3 or Rac1 strongly reduced the invasiveness of αvβ3high cells, whereas the invasiveness of β3 specific knock

  13. The integrin alphav beta3 increases cellular stiffness and cytoskeletal remodeling dynamics to facilitate cancer cell invasion

    International Nuclear Information System (INIS)

    Mierke, Claudia Tanja

    2013-01-01

    The process of cancer cell invasion through the extracellular matrix (ECM) of connective tissue plays a prominent role in tumor progression and is based fundamentally on biomechanics. Cancer cell invasion usually requires cell adhesion to the ECM through the cell-matrix adhesion receptors integrins. The expression of the αvβ3 integrin is increased in several tumor types and is consistently associated with increased metastasis formation in patients. The hypothesis was that the αvβ3 integrin expression increases the invasiveness of cancer cells through increased cellular stiffness, and increased cytoskeletal remodeling dynamics. Here, the invasion of cancer cells with different αvβ3 integrin expression levels into dense three-dimensional (3D) ECMs has been studied. Using a cell sorter, two subcell lines expressing either high or low amounts of αvβ3 integrins (αvβ3 high or αvβ3 low cells, respectively) have been isolated from parental MDA-MB-231 breast cancer cells. αvβ3 high cells showed a threefold increased cell invasion compared to αvβ3 low cells. Similar results were obtained for A375 melanoma, 786-O kidney and T24 bladder carcinoma cells, and cells in which the β3 integrin subunit was knocked down using specific siRNA. To investigate whether contractile forces are essential for αvβ3 integrin-mediated increased cellular stiffness and subsequently enhanced cancer cell invasion, invasion assays were performed in the presence of myosin light chain kinase inhibitor ML-7 and Rho kinase inhibitor Y27632. Indeed, cancer cell invasiveness was reduced after addition of ML-7 and Y27632 in αvβ3 high cells but not in αvβ3 low cells. Moreover, after addition of the contractility enhancer calyculin A, an increase in pre-stress in αvβ3 low cells was observed, which enhanced cellular invasiveness. In addition, inhibition of the Src kinase, STAT3 or Rac1 strongly reduced the invasiveness of αvβ3 high cells, whereas the invasiveness of β3 specific knock

  14. The Interaction of CD154 with the α5β1 Integrin Inhibits Fas-Induced T Cell Death.

    Science.gov (United States)

    Bachsais, Meriem; Naddaf, Nadim; Yacoub, Daniel; Salti, Suzanne; Alaaeddine, Nada; Aoudjit, Fawzi; Hassan, Ghada S; Mourad, Walid

    2016-01-01

    CD154, a critical regulator of the immune response, is usually associated with chronic inflammatory, autoimmune diseases as well as malignant disorders. In addition to its classical receptor CD40, CD154 is capable of binding other receptors, members of the integrin family, the αIIbβ3, αMβ2 and α5β1. Given the role attributed to integrins and particularly the β1 integrins in inhibiting apoptotic events in normal as well as malignant T cells, we were highly interested in investigating the role of the CD154/α5β1 interaction in promoting survival of malignant T cells contributing as such to tumor development and/or propagation. To support our hypothesis, we first show that soluble CD154 binds to the T-cell acute lymphoblastic leukemia cell line, Jurkat E6.1 in a α5β1-dependent manner. Binding of soluble CD154 to α5β1 integrin of Jurkat cells leads to the activation of key survival proteins, including the p38 and ERK1/2 mitogen-activated protein kinases (MAPKs), phosphoinositide 3 kinase (PI-3K), and Akt. Interestingly, soluble CD154 significantly inhibits Fas-mediated apoptosis in T cell leukemia-lymphoma cell lines, Jurkat E6.1 and HUT78 cells, an important hallmark of T cell survival during malignancy progression. These anti-apoptotic effects were mainly mediated by the activation of the PI-3K/Akt pathway but also involved the p38 and the ERK1/2 MAPKs cascades. Our data also demonstrated that the CD154-triggered inhibition of the Fas-mediated cell death response was dependent on a suppression of caspase-8 cleavage, but independent of de novo protein synthesis or alterations in Fas expression on cell surface. Together, our results highlight the impact of the CD154/α5β1 interaction in T cell function/survival and identify novel targets for the treatment of malignant disorders, particularly of T cell origin.

  15. The Interaction of CD154 with the α5β1 Integrin Inhibits Fas-Induced T Cell Death.

    Directory of Open Access Journals (Sweden)

    Meriem Bachsais

    Full Text Available CD154, a critical regulator of the immune response, is usually associated with chronic inflammatory, autoimmune diseases as well as malignant disorders. In addition to its classical receptor CD40, CD154 is capable of binding other receptors, members of the integrin family, the αIIbβ3, αMβ2 and α5β1. Given the role attributed to integrins and particularly the β1 integrins in inhibiting apoptotic events in normal as well as malignant T cells, we were highly interested in investigating the role of the CD154/α5β1 interaction in promoting survival of malignant T cells contributing as such to tumor development and/or propagation. To support our hypothesis, we first show that soluble CD154 binds to the T-cell acute lymphoblastic leukemia cell line, Jurkat E6.1 in a α5β1-dependent manner. Binding of soluble CD154 to α5β1 integrin of Jurkat cells leads to the activation of key survival proteins, including the p38 and ERK1/2 mitogen-activated protein kinases (MAPKs, phosphoinositide 3 kinase (PI-3K, and Akt. Interestingly, soluble CD154 significantly inhibits Fas-mediated apoptosis in T cell leukemia-lymphoma cell lines, Jurkat E6.1 and HUT78 cells, an important hallmark of T cell survival during malignancy progression. These anti-apoptotic effects were mainly mediated by the activation of the PI-3K/Akt pathway but also involved the p38 and the ERK1/2 MAPKs cascades. Our data also demonstrated that the CD154-triggered inhibition of the Fas-mediated cell death response was dependent on a suppression of caspase-8 cleavage, but independent of de novo protein synthesis or alterations in Fas expression on cell surface. Together, our results highlight the impact of the CD154/α5β1 interaction in T cell function/survival and identify novel targets for the treatment of malignant disorders, particularly of T cell origin.

  16. In vitro X-ray irradiation of human peripheral blood T lymphocytes enhances suppressor function

    International Nuclear Information System (INIS)

    Ogawa, H.; Tsunematsu, T.

    1983-01-01

    The effect of in vitro X-ray irradiation on human peripheral blood T lymphocytes was studied with regard to their suppressor activity related to the concanavalin A (Con A)-induced suppressor system. To generate suppressor T lymphocytes, purified human T lymphocytes were incubated for 3 days in the first culture, with or without Con A. These lymphocytes were irradiated with various doses of X-ray before, mid or after the culture. After doing a second culture for 6 days, the suppressive influence of these cells on T lymphocyte proliferation rates stimulated with allogeneic mononuclear cells, and B lymphocyte proliferation rates stimulated with pokeweed mitogen was measured. Irradiation of cultures to which Con A had not been added induced much the same level of suppressor activity as seen in the cultures with Con A. The suppressor activity gradually increased with time from the irradiation to the suppressor cell assay. Suppressor T lymphocytes were resistant to X-ray irradiation and independent of DNA synthesis. However, irradiation-induced enhancement was minimal in cultures incubated with con A, regardless of the irradiation time. (author)

  17. α5β1-Integrin inhibitor (CLT-28643) effective in rabbit trabeculectomy model.

    Science.gov (United States)

    Schultheiss, Maximilian; Schnichels, Sven; Konrad, Eva-Maria; Bartz-Schmidt, Karl U; Zahn, Grit; Caldirola, Patrizia; Fsadni, Mario G; Caram-Lelham, Ninus; Spitzer, Martin S

    2017-02-01

    Glaucoma filtration surgery (GFS) fails due to fibrosis. The α5β1-integrin plays a pivotal role in fibrosis, angiogenesis and inflammation. This is the first experiment evaluating the prevention of fibrosis after GFS by a specific small molecule α5β1-integrin inhibitor (CLT-28643). Twenty-four rabbits received trabeculectomy on their right eyes. The rabbits were randomized into three groups of eight eyes each. CLT-28643 was given as a single subconjunctival injection intraoperatively to two of the right eye groups followed by postoperative vehicle eye drops (CLT+ group) or CLT-28643 eye drops 4 times daily (CLT++ group). A third group received mitomycin-C (MMC) intraoperatively (sponge application, 0.04%, 2 min) followed by vehicle eye drops postoperatively. The control-surgery group consisted of 12 left eyes having trabeculectomy with no adjunctive therapy. The remaining 12 left eyes formed the untreated group. Clinical assessment included intraocular pressure (IOP) measurement, slit-lamp examination (including bleb survival and morphology) and bleb photography. The rabbits were killed after four weeks for histology. Both CLT-28643-treated groups showed significantly prolonged bleb survival, and better bleb score compared to the control-surgery group. At end of the study, most functioning blebs were found in the MMC group (MMC group 75%; CLT+ group 12.5%, CLT++ group 25%; CLT+ group 12.5%, control-surgery group 0%). CLT-28643 was non-toxic and well tolerated. This rabbit GFS study indicates that inhibition of α5β1-integrin by the novel α5β1-integrin antagonist CLT-28643 significantly improved the outcome. The effect of a single intro-operative application of CLT-28643 seems to be inferior to 0.04% MMC. © 2016 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  18. PTP1B triggers integrin-mediated repression of myosin activity and modulates cell contractility

    Directory of Open Access Journals (Sweden)

    Ana E. González Wusener

    2016-01-01

    Full Text Available Cell contractility and migration by integrins depends on precise regulation of protein tyrosine kinase and Rho-family GTPase activities in specific spatiotemporal patterns. Here we show that protein tyrosine phosphatase PTP1B cooperates with β3 integrin to activate the Src/FAK signalling pathway which represses RhoA-myosin-dependent contractility. Using PTP1B null (KO cells and PTP1B reconstituted (WT cells, we determined that some early steps following cell adhesion to fibronectin and vitronectin occurred robustly in WT cells, including aggregation of β3 integrins and adaptor proteins, and activation of Src/FAK-dependent signalling at small puncta in a lamellipodium. However, these events were significantly impaired in KO cells. We established that cytoskeletal strain and cell contractility was highly enhanced at the periphery of KO cells compared to WT cells. Inhibition of the Src/FAK signalling pathway or expression of constitutive active RhoA in WT cells induced a KO cell phenotype. Conversely, expression of constitutive active Src or myosin inhibition in KO cells restored the WT phenotype. We propose that this novel function of PTP1B stimulates permissive conditions for adhesion and lamellipodium assembly at the protruding edge during cell spreading and migration.

  19. PTP1B triggers integrin-mediated repression of myosin activity and modulates cell contractility

    Science.gov (United States)

    González Wusener, Ana E.; González, Ángela; Nakamura, Fumihiko; Arregui, Carlos O.

    2016-01-01

    ABSTRACT Cell contractility and migration by integrins depends on precise regulation of protein tyrosine kinase and Rho-family GTPase activities in specific spatiotemporal patterns. Here we show that protein tyrosine phosphatase PTP1B cooperates with β3 integrin to activate the Src/FAK signalling pathway which represses RhoA-myosin-dependent contractility. Using PTP1B null (KO) cells and PTP1B reconstituted (WT) cells, we determined that some early steps following cell adhesion to fibronectin and vitronectin occurred robustly in WT cells, including aggregation of β3 integrins and adaptor proteins, and activation of Src/FAK-dependent signalling at small puncta in a lamellipodium. However, these events were significantly impaired in KO cells. We established that cytoskeletal strain and cell contractility was highly enhanced at the periphery of KO cells compared to WT cells. Inhibition of the Src/FAK signalling pathway or expression of constitutive active RhoA in WT cells induced a KO cell phenotype. Conversely, expression of constitutive active Src or myosin inhibition in KO cells restored the WT phenotype. We propose that this novel function of PTP1B stimulates permissive conditions for adhesion and lamellipodium assembly at the protruding edge during cell spreading and migration. PMID:26700725

  20. The association between cigarette smoking, virologic suppression, and CD4+ lymphocyte count in HIV-Infected Russian women.

    Science.gov (United States)

    Brown, Jennifer L; Winhusen, Theresa; DiClemente, Ralph J; Sales, Jessica M; Rose, Eve S; Safonova, Polina; Levina, Olga; Belyakov, Nikolay; Rassokhin, Vadim V

    2017-09-01

    Cigarette smoking among people living with HIV/AIDS is associated with significant morbidity and mortality, but findings regarding the association between cigarette smoking and HIV viral load and CD4+ lymphocyte counts have been inconsistent. This study characterized the prevalence of cigarette smoking among HIV-infected Russian women and examined the association between smoking frequency and quantity and HIV viral load and CD4+ lymphocyte counts. HIV-infected Russian women (N = 250; M age = 30.0) in St. Petersburg, Russia, completed an audio computer-assisted self-interview survey assessing cigarette use, antiretroviral medication adherence, and provided blood samples assayed for HIV viral load and CD4+ lymphocyte counts. The majority (60.4%) reported cigarette smoking in the past month; 49.0% of recent smokers were classified as moderate or heavy smokers, defined as smoking ≥10 cigarettes daily. Viral load status did not differ between infrequent smokers and regular smokers. However, moderate/heavy smokers (relative to light smokers) were more likely to have a detectable viral load (AOR = 2.3, 95% CI: 1.1, 5.1). There were no significant differences in CD4+ lymphocyte counts by smoking frequency or quantity of cigarettes smoked. Results highlight the need for additional research to examine the association between cigarette smoking and virologic suppression and markers of HIV disease progression. Adverse health consequences of cigarette smoking coupled with a potential link between heavy smoking and poor virologic suppression highlight the need for assessment of cigarette use and provision of evidence-based smoking-cessation interventions within HIV medical care.

  1. Can alterations in integrin and laminin-5 expression be used as markers of malignancy?

    DEFF Research Database (Denmark)

    Thorup, Alis Karabulut; Reibel, J.; Schjødt, Morten

    1998-01-01

    Integrins, laminin-5, cell adhesion molecules, oral, leukoplakia, premalignant, squamous cell carcinomas......Integrins, laminin-5, cell adhesion molecules, oral, leukoplakia, premalignant, squamous cell carcinomas...

  2. Functional role of CD11c+ monocytes in atherogenesis associated with hypercholesterolemia

    Science.gov (United States)

    Monocyte activation and migration into the arterial wall are key events in atherogenesis associated with hypercholesterolemia. CD11c/CD18, a beta2 integrin expressed on human monocytes and a subset of mouse monocytes, has been shown to play a distinct role in human monocyte adhesion on endothelial c...

  3. Lamellipodia nucleation by filopodia depends on integrin occupancy and downstream Rac1 signaling

    International Nuclear Information System (INIS)

    Guillou, Herve; Depraz-Depland, Adeline; Planus, Emmanuelle; Vianay, Benoit; Chaussy, Jacques; Grichine, Alexei; Albiges-Rizo, Corinne; Block, Marc R.

    2008-01-01

    Time-lapse video-microscopy unambiguously shows that fibroblast filopodia are the scaffold of lamellipodia nucleation that allows anisotropic cell spreading. This process was dissected into elementary stages by monitoring cell adhesion on micropatterned extracellular matrix arrays of various pitches. Adhesion structures are stabilized by contact with the adhesive plots and subsequently converted into lamellipodia-like extensions starting at the filopodia tips. This mechanism progressively leads to full cell spreading. Stable expression of the dominant-negative Rac1 N17 impairs this change in membrane extension mode and stops cell spreading on matrix arrays. Similar expression of the dominant-negative Cdc42 N17 impairs cell spreading on homogenous and structured substrate, suggesting that filopodia extension is a prerequisite for cell spreading in this model. The differential polarity of the nucleation of lamellipodial structures by filopodia on homogenous and structured surfaces starting from the cell body and of filopodia tip, respectively, suggested that this process is triggered by areas that are in contact with extracellular matrix proteins for longer times. Consistent with this view, wild-type cells cannot spread on microarrays made of function blocking or neutral anti-β 1 integrin antibodies. However, stable expression of a constitutively active Rac1 mutant rescues the cell ability to spread on these integrin microarrays. Thereby, lamellipodia nucleation by filopodia requires integrin occupancy by matrix substrate and downstream Rac1 signaling

  4. Arachidonic acid metabolites in normal and autoimmune mice do not influence lymphocyte-high endothelial venule interactions.

    Science.gov (United States)

    Manolios, N; Bakiera, B; Geczy, C L; Schrieber, L

    1991-02-01

    In peripheral lymphoid organs the number of lymphocytes and the proportion of functional lymphocyte subsets are regulated by multiple factors including the control of lymphocyte migration by selective lymphocyte-high endothelial venule (HEV) interactions. In this study, prostaglandin E2 (PGE2) levels from normal and autoimmune mouse lymph node cells were measured. The contribution of eicosanoids to lymphocyte-HEV interactions in normal (CBA/T6) and autoimmune (MRL/n) mice was examined. There was no association between PGE2 production in normal or autoimmune mice and the age of onset of disease activity in the latter strains. Arachidonic acid metabolites, in particular PGE2 and leukotriene B4 (LTB4), did not have any effects on lymphocyte-HEV binding. Likewise, lymphocytes treated in vivo and/or in vitro with arachidonic acid metabolite inhibitors (acetyl salicylic acid, indomethacin, BW755C) did not alter lymphocyte-HEV binding interactions in both normal and autoimmune mice. No clinical significance could be attributed to lymph node PGE2 production and the age of onset of autoimmune disease. In summary, these findings cast doubt on the role of arachidonic acid metabolites in lymphocyte-HEV binding interactions.

  5. SU9516 Increases α7β1 Integrin and Ameliorates Disease Progression in the mdx Mouse Model of Duchenne Muscular Dystrophy.

    Science.gov (United States)

    Sarathy, Apurva; Wuebbles, Ryan D; Fontelonga, Tatiana M; Tarchione, Ashley R; Mathews Griner, Lesley A; Heredia, Dante J; Nunes, Andreia M; Duan, Suzann; Brewer, Paul D; Van Ry, Tyler; Hennig, Grant W; Gould, Thomas W; Dulcey, Andrés E; Wang, Amy; Xu, Xin; Chen, Catherine Z; Hu, Xin; Zheng, Wei; Southall, Noel; Ferrer, Marc; Marugan, Juan; Burkin, Dean J

    2017-06-07

    Duchenne muscular dystrophy (DMD) is a fatal muscle disease caused by mutations in the dystrophin gene, resulting in a complete loss of the dystrophin protein. Dystrophin is a critical component of the dystrophin glycoprotein complex (DGC), which links laminin in the extracellular matrix to the actin cytoskeleton within myofibers and provides resistance to shear stresses during muscle activity. Loss of dystrophin in DMD patients results in a fragile sarcolemma prone to contraction-induced muscle damage. The α7β1 integrin is a laminin receptor protein complex in skeletal and cardiac muscle and a major modifier of disease progression in DMD. In a muscle cell-based screen for α7 integrin transcriptional enhancers, we identified a small molecule, SU9516, that promoted increased α7β1 integrin expression. Here we show that SU9516 leads to increased α7B integrin in murine C2C12 and human DMD patient myogenic cell lines. Oral administration of SU9516 in the mdx mouse model of DMD increased α7β1 integrin in skeletal muscle, ameliorated pathology, and improved muscle function. We show that these improvements are mediated through SU9516 inhibitory actions on the p65-NF-κB pro-inflammatory and Ste20-related proline alanine rich kinase (SPAK)/OSR1 signaling pathways. This study identifies a first in-class α7 integrin-enhancing small-molecule compound with potential for the treatment of DMD. Copyright © 2017 The American Society of Gene and Cell Therapy. All rights reserved.

  6. Association of inclusion body myositis with T cell large granular lymphocytic leukaemia

    DEFF Research Database (Denmark)

    Greenberg, Steven A; Pinkus, Jack L; Amato, Anthony A

    2016-01-01

    SEE HOHLFELD AND SCHULZE-KOOPS DOI101093/BRAIN/AWW053 FOR A SCIENTIFIC COMMENTARY ON THIS ARTICLE: Inclusion body myositis and T cell large granular lymphocytic leukaemia are rare diseases involving pathogenic cytotoxic CD8+ T cells. After encountering four patients with both disorders, we...... prospectively screened 38 patients with inclusion body myositis for the presence of expanded large granular lymphocyte populations by standard clinical laboratory methods (flow cytometry, examination of blood smears, and T cell receptor gene rearrangements), and performed muscle immunohistochemistry for CD8, CD......57, and TIA1. Most (22/38; 58%) patients with inclusion body myositis had aberrant populations of large granular lymphocytes in their blood meeting standard diagnostic criteria for T cell large granular lymphocytic leukaemia. These T cell populations were clonal in 20/20 patients and stably present...

  7. Targeting of beta 1 integrins impairs DNA repair for radiosensitization of head and neck cancer cells

    NARCIS (Netherlands)

    Dickreuter, E.; Eke, I.; Krause, M.; Borgmann, K.; van Vugt, M. A.; Cordes, N.

    2016-01-01

    beta 1 Integrin-mediated cell-extracellular matrix interactions allow cancer cell survival and confer therapy resistance. It was shown that inhibition of beta 1 integrins sensitizes cells to radiotherapy. Here, we examined the impact of beta 1 integrin targeting on the repair of radiation-induced

  8. Associations of Circulating Lymphocyte Subpopulations with Type 2 Diabetes: Cross-Sectional Results from the Multi-Ethnic Study of Atherosclerosis (MESA.

    Directory of Open Access Journals (Sweden)

    Nels C Olson

    Full Text Available Distinct lymphocyte subpopulations have been implicated in the regulation of glucose homeostasis and obesity-associated inflammation in mouse models of insulin resistance. Information on the relationships of lymphocyte subpopulations with type 2 diabetes remain limited in human population-based cohort studies.Circulating levels of innate (γδ T, natural killer (NK and adaptive immune (CD4+ naive, CD4+ memory, Th1, and Th2 lymphocyte subpopulations were measured by flow cytometry in the peripheral blood of 929 free-living participants of the Multi-Ethnic Study of Atherosclerosis (MESA. Cross-sectional relationships of lymphocyte subpopulations with type 2 diabetes (n = 154 and fasting glucose and insulin concentrations were evaluated by generalized linear models.Each standard deviation (SD higher CD4+ memory cells was associated with a 21% higher odds of type 2 diabetes (95% CI: 1-47% and each SD higher naive cells was associated with a 22% lower odds (95% CI: 4-36% (adjusted for age, gender, race/ethnicity, and BMI. Among participants not using diabetes medication, higher memory and lower naive CD4+ cells were associated with higher fasting glucose concentrations (p<0.05, adjusted for age, sex, and race/ethnicity. There were no associations of γδ T, NK, Th1, or Th2 cells with type 2 diabetes, glucose, or insulin.A higher degree of chronic adaptive immune activation, reflected by higher memory and lower naive CD4+ cells, was positively associated with type 2 diabetes. These results are consistent with a role of chronic immune activation and exhaustion augmenting chronic inflammatory diseases, and support the importance of prospective studies evaluating adaptive immune activation and type 2 diabetes.

  9. β1 integrins regulate chondrogenesis and rock signaling in adipose stem cells

    NARCIS (Netherlands)

    Lu, Z.F.; Doulabi, B.Z.; Huang, C.L.; Bank, R.A.; Helder, M.N.

    2008-01-01

    β1 integrins play a controversial role during chondrogenesis. Since the maturation of chondrocytes relies on a signaling switch from cell-cell to cell-matrix interactions, we hypothesized that β1 integrins play a different role at the earlier (mainly cell-cell interaction) from the later stage

  10. Influence of exogenous leptin on redox homeostasis in neutrophils and lymphocytes cultured in synovial fluid isolated from patients with rheumatoid arthritis

    Directory of Open Access Journals (Sweden)

    Michał Gajewski

    2016-07-01

    Full Text Available Objectives : Leptin is an adipose cells derived hormone that regulates energy homeostasis within the body. Energy metabolism of immune cells influences their activity within numerous pathological states, but the effect of leptin on these cells in unclear. On the one hand, it was observed that leptin induces neutrophils chemotaxis and modulates phagocytosis. On the other hand, neutrophils exposed to leptin did not display detectable Ca 2+ ions mobilization or β 2 -integrin upregulation. In this study, we investigated the effect of leptin on the redox homeostasis in lymphocytes and neutrophils. Material and methods : Neutrophils and lymphocytes were isolated by density-gradient centrifugation of blood from healthy volunteers. Cells were cultured with or without leptin (100 ng/ml for lymphocytes and 500 ng/ml for neutrophils or with or without synovial fluid (85% for 0–72 h. Culture media were not changed during incubation. Cells were homogenized and homogenate was frozen until laboratory measurements. Redox homeostasis was assessed by the reduced glutathione (GSH vs. oxidized glutathione (GSSG ratio and membrane lipid peroxidation evaluation. Results : Lymphocytes cultured with leptin and synovial fluid showed a significant increase of the GSSG level. The GSSG/GSH ratio increased by 184 ±37%. In neutrophils incubated in a similar environment, the GSSG/GSH ratio increased by just 21 ±7%, and the effect was observed irrespectively of whether they were exposed to leptin or synovial fluid or both together. Neither leptin nor synovial fluid influenced lipid peroxidation in neutrophils, but in lymphocytes leptin intensified lipid peroxidation. Conclusions : Leptin altered the lymphocytes, but not neutrophils redox state. Because firstly neutrophils are anaerobic cells and have just a few mitochondria and secondly lymphocytes have typical aerobic metabolism, the divergence of our data supports the hypothesis that leptin induces oxidative stress by

  11. N-cadherin and integrin blockade inhibit arteriolar myogenic reactivity but not pressure-induced increases in intracellular Ca2+

    Directory of Open Access Journals (Sweden)

    Teresa Y. Jackson

    2010-12-01

    Full Text Available The vascular myogenic response is characterized by arterial constriction in response to an increase in intraluminal pressure and dilatation to a decrease in pressure. This mechanism is important for the regulation of blood flow, capillary pressure and arterial pressure. The identity of the mechanosensory mechanism(s for this response is incompletely understood but has been shown to include the integrins as cell-extracellular matrix receptors. The possibility that a cell-cell adhesion receptor is involved has not been studied. Thus, we tested the hypothesis that N-cadherin, a cell-cell adhesion molecule in vascular smooth muscle cells (VSMCs, was important for myogenic responsiveness. The purpose of this study was to investigate:
    1. whether cadherin inhibition blocks myogenic responses to increases in intraluminal pressure and 2. the effect of the cadherin or integrin blockade on pressure-induced changes in [Ca2+]i. Cadherin blockade was tested in isolated rat cremaster arterioles on myogenic responses to acute pressure steps from 60 – 100 mmHg and changes in VSMC Ca2+ were measured using fura-2. In the presence of a synthetic cadherin inhibitory peptide or a function blocking antibody, myogenic responses were inhibited. In contrast, during N-cadherin blockade, pressure-induced changes in [Ca2+]i were not altered. Similarly, vessels treated with function-blocking β1- or β3-integrin antibodies maintained pressure-induced [Ca2+]i responses despite inhibition of myogenic constriction. Collectively, these data suggest that both cadherins and integrins play a fundamental role in mediating myogenic constriction but argue against their direct involvement in mediating pressure-induced [Ca2+]i increases.

  12. Indium-labelled human gut-derived T cells from healthy subjects with strong in vitro adhesion to MAdCAM-1 show no detectable homing to the gut in vivo

    DEFF Research Database (Denmark)

    Rømer, Johanne Lade

    2004-01-01

    Integrin alpha4beta 7 is the principal gut-homing receptor, and it is assumed that expression of this specific integrin directs lymphocytes to the gut in vivo. Adoptive cellular immunotherapy against inflammatory bowel disease (IBD) may depend on the expression of integrin alpha4beta 7...

  13. Inhibitory effects of various oxygenated sterols on the differentiation and function of tumor-specific cytotoxic T lymphocytes

    International Nuclear Information System (INIS)

    Spangrude, G.J.; Sherris, D.; Daynes, R.A.

    1982-01-01

    Irradiation of skin with ultraviolet light (UVL) is capable of causing many biological and biochemical changes in this complex organ. One early consequence is the oxidation of epidermal plasma membrane cholesterol, causing the induction of a wide variety of photoproducts. It is well recognized that some oxygenated sterols possess potent biological activity on mammalian cells by their ability to inhibit endogeneous mevalonate and cholesterol biosynthesis. In the few immunological systems that have been studied, there is general agreement that lymphocyte function is lacking, as both afferent and efferent blockades have been suggested. These studies were undertaken to determine the effect of various oxygenated sterols (representing a number of known cholesterol-derived photoproducts) on the generation (afferent) and function (efferent) of cytotoxic T lymphocytes (CTLs). Cell-mediated immune responses which result in the generation of both alloantigen-specific and syngeneic tumor-specific CTLs were evaluated

  14. Alpha5beta1 integrin-fibronectin interactions specify liquid to solid phase transition of 3D cellular aggregates.

    Directory of Open Access Journals (Sweden)

    Carlos E Caicedo-Carvajal

    2010-07-01

    of control between integrins and the ECM that can influence tissue cohesion and other mechanical properties, which may translate to the specification of tissue structure and function. These studies provide insights into important biological processes such as embryonic development, wound healing, and for tissue engineering applications.

  15. DMPD: Immunoreceptor-like signaling by beta 2 and beta 3 integrins. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 17913496 Immunoreceptor-like signaling by beta 2 and beta 3 integrins. Jakus Z, Fod...) Show Immunoreceptor-like signaling by beta 2 and beta 3 integrins. PubmedID 17913496 Title Immunoreceptor-...like signaling by beta 2 and beta 3 integrins. Authors Jakus Z, Fodor S, Abram CL

  16. Targeting α4β7 integrin reduces mucosal transmission of simian immunodeficiency virus and protects gut-associated lymphoid tissue from infection.

    Science.gov (United States)

    Byrareddy, Siddappa N; Kallam, Brianne; Arthos, James; Cicala, Claudia; Nawaz, Fatima; Hiatt, Joseph; Kersh, Ellen N; McNicholl, Janet M; Hanson, Debra; Reimann, Keith A; Brameier, Markus; Walter, Lutz; Rogers, Kenneth; Mayne, Ann E; Dunbar, Paul; Villinger, Tara; Little, Dawn; Parslow, Tristram G; Santangelo, Philip J; Villinger, Francois; Fauci, Anthony S; Ansari, Aftab A

    2014-12-01

    α4β7 integrin-expressing CD4(+) T cells preferentially traffic to gut-associated lymphoid tissue (GALT) and have a key role in HIV and simian immunodeficiency virus (SIV) pathogenesis. We show here that the administration of an anti-α4β7 monoclonal antibody just prior to and during acute infection protects rhesus macaques from transmission following repeated low-dose intravaginal challenges with SIVmac251. In treated animals that became infected, the GALT was significantly protected from infection and CD4(+) T cell numbers were maintained in both the blood and the GALT. Thus, targeting α4β7 reduces mucosal transmission of SIV in macaques.

  17. Muscle-specific integrins in masseter muscle fibers of chimpanzees: an immunohistochemical study.

    Directory of Open Access Journals (Sweden)

    Gianluigi Vaccarino

    2010-05-01

    Full Text Available Most notably, recent comparative genomic analyses strongly indicate that the marked differences between modern human and chimpanzees are likely due more to changes in gene regulation than to modifications of the genes. The most peculiar aspect of hominoid karyotypes is that human have 46 chromosomes whereas gorillas and chimpanzees have 48. Interestingly, human and chimpanzees do share identical inversions on chromosome 7 and 9 that are not evident in the gorilla karyotype. Thus, the general phylogeny suggests that humans and chimpanzees are sister taxa; based on this, it seems that human-chimpanzee sequence similarity is an astonishing 99%. At this purpose, of particular interest is the inactivation of the myosin heavy chain 16 (MYH16 gene, most prominently expressed in the masticatory muscle of mammals. It has been showed that the loss of this gene in humans may have resulted in smaller masticatory muscle and consequential changes to cranio-facial morphology and expansion of the human brain case. Powerful masticatory muscles are found in most primates; contrarily, in both modern and fossil member Homo, these muscles are considerably smaller. The evolving hominid masticatory apparatus shifted towards a pattern of gracilization nearly simultaneously with accelerated encephalization in early Homo. To better comprehend the real role of the MYH16 gene, we studied the primary proteins present in the muscle fibers of humans and non-humans, in order to understand if they really can be influenced by MYH16 gene. At this aim we examined the muscle-specific integrins, alpha 7B and beta 1D-integrins, and their relative fetal isoforms, alpha 7A and beta 1A-integrins, analyzing, by immunohistochemistry, muscle biopsies of two components of a chimpanzee's group in captivity, an alpha male and a non-alpha male subjects; all these integrins participate in vital biological processes such as maintenance of tissue integrity, embryonic development, cell

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

    Science.gov (United States)

    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

  19. Integrin activation dynamics between the RGD-binding site and the headpiece hinge.

    Science.gov (United States)

    Puklin-Faucher, Eileen; Vogel, Viola

    2009-12-25

    Integrins form mechanical links between the extracellular matrix and the cytoskeleton. Although integrin activation is known to be regulated by an allosteric conformational change, which can be induced from the extracellular or intracellular end of the molecule, little is known regarding the sequence of structural events by which signals propagate between distant sites. Here, we reveal with molecular dynamics simulations of the FnIII(10)-bound alpha(V)beta(3) integrin headpiece how the binding pocket and interdomain betaA/hybrid domain hinge on the distal end of the betaA domain are allosterically linked via a hydrophobic T-junction between the middle of the alpha1 helix and top of the alpha7 helix. The key results of this study are: 1) that this T-junction is induced by ligand binding and hinge opening, and thus displays bidirectionality; 2) that formation of this junction can be accelerated by ligand-mediated force; and 3) how formation of this junction is inhibited by Ca(2+) in place of Mg(2+) at the site adjacent to the metal ion-dependent adhesion site ("ADMIDAS"). Together with recent experimental evidence that integrin complexes can form catch bonds (i.e. become strengthened under force), as well as earlier evidence that Ca(2+) at the ADMIDAS results in lower binding affinity, these simulations provide a common structural model for the dynamic process by which integrins become activated.

  20. β5 Integrin Up-Regulation in Brain-Derived Neurotrophic Factor Promotes Cell Motility in Human Chondrosarcoma

    Science.gov (United States)

    Li, Te-Mao; Fong, Yi-Chin; Liu, Shan-Chi; Chen, Po-Chun; Tang, Chih-Hsin

    2013-01-01

    Chondrosarcoma is a primary malignant bone cancer, with a potent capacity to invade locally and cause distant metastasis; it has a poor prognosis and shows a predilection for metastasis to the lungs. Brain derived neurotrophic factor (BDNF) is a small-molecule protein from the neurotrophin family of growth factors that is associated with the disease status and outcomes of cancers. However, the effect of BDNF on migration activity in human chondrosarcoma cells is mostly unknown. Here, we found that human chondrosarcoma tissues showed significant expression of BDNF, which was higher than that in normal cartilage and primary chondrocytes. We also found that BDNF increased the migration and expression of β5 integrin in human chondrosarcoma cells. In addition, knockdown of BDNF expression markedly inhibited migratory activity. BDNF-mediated migration and β5 integrin up-regulation were attenuated by antibody, inhibitor, or siRNA against the TrkB receptor. Pretreatment of chondrosarcoma cells with PI3K, Akt, and NF-κB inhibitors or mutants also abolished BDNF-promoted migration and integrin expression. The PI3K, Akt, and NF-κB signaling pathway was activated after BDNF treatment. Taken together, our results indicate that BDNF enhances the migration of chondrosarcoma by increasing β5 integrin expression through a signal transduction pathway that involves the TrkB receptor, PI3K, Akt, and NF-κB. BDNF thus represents a promising new target for treating chondrosarcoma metastasis. PMID:23874483

  1. Role of integrin-linked kinase for functional capacity of endothelial progenitor cells in patients with stable coronary artery disease

    International Nuclear Information System (INIS)

    Werner, Christian; Boehm, Michael; Friedrich, Erik B.

    2008-01-01

    Number and function of endothelial progenitor cells (EPCs) are down-regulated in patients with coronary artery disease (CAD). Integrin-linked kinase (ILK) is a signal and adaptor protein that regulates survival of mature endothelial cells and vascular development. Here we show that EPC dysfunction in patients with CAD is paralleled by down-regulation of ILK while restoration of ILK expression rescues the migratory defect of CAD-EPCs. Human EPCs transduced with dominant-negative ILK (DN-ILK) display significantly reduced expression of CD34 + /VEGFR-2 + , DiI-Ac-LDL uptake, and Ulex europaeus lectin binding. Mechanistically, DN-ILK-transfected EPCs are characterized by decreased proliferation, while proliferation is increased in wild-type ILK-transfected EPCs. These effects are paralleled by changes in cyclin D1 expression, colony forming units, and cytoskeletal rearrangement. Functionally, ILK is necessary and sufficient for SDF-1-triggered migration and adhesion in EPCs. These data extend current knowledge about the role of ILK in EPC biology and implicate ILK as a therapeutic target in CAD.

  2. T gamma/delta lymphocytes in renal transplant recipients

    NARCIS (Netherlands)

    Raasveld, M. H.; Bloemena, E.; Surachno, S.; ten Berge, R. J.

    1992-01-01

    T gamma/delta lymphocytes are able to perform allospecific cytotoxicity and natural killer cytotoxicity in vitro. However, very little is known about their function in vivo. To investigate the possible involvement of T gamma/delta lymphocytes in the immune response to renal allografts, fine-needle

  3. Upregulated expression of integrin α1 in mesangial cells and integrin α3 and vimentin in podocytes of Col4a3-null (Alport mice.

    Directory of Open Access Journals (Sweden)

    Brooke M Steenhard

    Full Text Available Alport disease in humans, which usually results in proteinuria and kidney failure, is caused by mutations to the COL4A3, COL4A4, or COL4A5 genes, and absence of collagen α3α4α5(IV networks found in mature kidney glomerular basement membrane (GBM. The Alport mouse harbors a deletion of the Col4a3 gene, which also results in the lack of GBM collagen α3α4α5(IV. This animal model shares many features with human Alport patients, including the retention of collagen α1α2α1(IV in GBMs, effacement of podocyte foot processes, gradual loss of glomerular barrier properties, and progression to renal failure. To learn more about the pathogenesis of Alport disease, we undertook a discovery proteomics approach to identify proteins that were differentially expressed in glomeruli purified from Alport and wild-type mouse kidneys. Pairs of cy3- and cy5-labeled extracts from 5-week old Alport and wild-type glomeruli, respectively, underwent 2-dimensional difference gel electrophoresis. Differentially expressed proteins were digested with trypsin and prepared for mass spectrometry, peptide ion mapping/fingerprinting, and protein identification through database searching. The intermediate filament protein, vimentin, was upregulated ∼2.5 fold in Alport glomeruli compared to wild-type. Upregulation was confirmed by quantitative real time RT-PCR of isolated Alport glomeruli (5.4 fold over wild-type, and quantitative confocal immunofluorescence microscopy localized over-expressed vimentin specifically to Alport podocytes. We next hypothesized that increases in vimentin abundance might affect the basement membrane protein receptors, integrins, and screened Alport and wild-type glomeruli for expression of integrins likely to be the main receptors for GBM type IV collagen and laminin. Quantitative immunofluorescence showed an increase in integrin α1 expression in Alport mesangial cells and an increase in integrin α3 in Alport podocytes. We conclude that

  4. Beta1 integrin inhibits apoptosis induced by cyclic stretch in annulus fibrosus cells via ERK1/2 MAPK pathway.

    Science.gov (United States)

    Zhang, Kai; Ding, Wei; Sun, Wei; Sun, Xiao-jiang; Xie, You-zhuan; Zhao, Chang-qing; Zhao, Jie

    2016-01-01

    Low back pain is associated with intervertebral disc degeneration (IVDD) due to cellular loss through apoptosis. Mechanical factors play an important role in maintaining the survival of the annulus fibrosus (AF) cells and the deposition of extracellular matrix. However, the mechanisms that excessive mechanical forces lead to AF cell apoptosis are not clear. The present study was to look for how AF cells sense mechanical changes. In vivo experiments, the involvement of mechanoreceptors in apoptosis was examined by RT-PCR and/or immunoblotting in the lumbar spine of rats subjected to unbalanced dynamic and static forces. In vitro experiments, we investigated apoptotic signaling pathways in untransfected and transfected AF cells with the lentivirus vector for rat β1 integrin overexpression after cyclic stretch. Apoptosis in AF cells was assessed using flow cytometry, Hoechst 33258 nuclear staining. Western blotting was used to analyze expression of β1 integrin and caspase-3 and ERK1/2 MAPK signaling molecules. In the rat IVDD model, unbalanced dynamic and static forces induced apoptosis of disc cells, which corresponded to decreased expression of β1 integrin. Cyclic stretch-induced apoptosis in rat AF cells correlated with the activation of caspase-3 and with decreased levels of β1 integrin and the phosphorylation levels of ERK1/2 activation level. However, the overexpression of β1 integrin in AF cells ameliorated cyclic stretch-induced apoptosis and decreased caspase-3 activation. Furthermore, ERK1/2-specific inhibitor promotes apoptosis in vector β1-infected AF cells. These results suggest that the disruption of β1 integrin signaling may underlie disc cell apoptosis induced by mechanical stress. Further work is necessary to fully elucidate the pathophysiological mechanisms that underlie IVDD caused by unbalanced dynamic and static forces.

  5. Boron Affects Immune Function Through Modulation of Splenic T Lymphocyte Subsets, Cytokine Secretion, and Lymphocyte Proliferation and Apoptosis in Rats.

    Science.gov (United States)

    Jin, Erhui; Li, Shenghe; Ren, Man; Hu, Qianqian; Gu, Youfang; Li, Kui

    2017-08-01

    This study demonstrated the mechanisms of boron effects in a rat model and provided a scientific basis for the rational of boron use. These findings were achieved by investigating the effects of boron (10, 20, 40, 80, 160, 320, and 640 mg/L in drinking water or 1.5, 3, 6, 12, 24, 48, and 96 mg/kg BW) on rat serum immunoglobulins (IgGs), splenic cytokines, lymphocyte subsets, as well as on lymphocyte proliferation and apoptosis. Addition of 20 (3) and 40 (6) mg/L (mg/kg BW) of boron to drinking water significantly increased rat serum IgG concentrations, splenic IFN-γ and IL-4 expression as well as the number of splenic CD3 + , CD4 + and proliferating cell nuclear antigen (PCNA) + cells. Supplementation of drinking water with 40 mg/L (6 mg/kg BW) boron also markedly increased splenic IL-2 expression and the CD4 + /CD8 + cell ratio and reduced splenic CD8 + cell number. Supplementation with 80 mg/L (12 mg/kg BW) boron significantly increased CD3 + and PCNA + cell numbers (P boron markedly reduced the serum IgG concentrations; splenic IL-2 and IL-10 expression; the number of CD3 + , CD4 + and PCNA + cells; and increased the number of splenic CD8 + and caspase-3 + cells and promoted caspase-3 expression in CD3 + cells. In conclusion, these findings suggest that the supplementation of rat drinking water with 20(3) and 40(6) mg/L (mg/kg BW) boron can markedly enhance humoral and cellular immune functions, while boron concentrations above 320 mg/L (48 mg/kg BW) can have an inhibitory effect or even toxicity on immune functions. These results exhibit a U-shaped response characteristic of low and high doses of boron supplementation on immune function and imply that proper boron supplementation in food for humans and animals could be used as an immunity regulator.

  6. Astrocytic αVβ3 integrin inhibits neurite outgrowth and promotes retraction of neuronal processes by clustering Thy-1.

    Directory of Open Access Journals (Sweden)

    Rodrigo Herrera-Molina

    Full Text Available Thy-1 is a membrane glycoprotein suggested to stabilize or inhibit growth of neuronal processes. However, its precise function has remained obscure, because its endogenous ligand is unknown. We previously showed that Thy-1 binds directly to α(Vβ(3 integrin in trans eliciting responses in astrocytes. Nonetheless, whether α(Vβ(3 integrin might also serve as a Thy-1-ligand triggering a neuronal response has not been explored. Thus, utilizing primary neurons and a neuron-derived cell line CAD, Thy-1-mediated effects of α(Vβ(3 integrin on growth and retraction of neuronal processes were tested. In astrocyte-neuron co-cultures, endogenous α(Vβ(3 integrin restricted neurite outgrowth. Likewise, α(Vβ(3-Fc was sufficient to suppress neurite extension in Thy-1(+, but not in Thy-1(- CAD cells. In differentiating primary neurons exposed to α(Vβ(3-Fc, fewer and shorter dendrites were detected. This effect was abolished by cleavage of Thy-1 from the neuronal surface using phosphoinositide-specific phospholipase C (PI-PLC. Moreover, α(Vβ(3-Fc also induced retraction of already extended Thy-1(+-axon-like neurites in differentiated CAD cells as well as of axonal terminals in differentiated primary neurons. Axonal retraction occurred when redistribution and clustering of Thy-1 molecules in the plasma membrane was induced by α(Vβ(3 integrin. Binding of α(Vβ(3-Fc was detected in Thy-1 clusters during axon retraction of primary neurons. Moreover, α(Vβ(3-Fc-induced Thy-1 clustering correlated in time and space with redistribution and inactivation of Src kinase. Thus, our data indicates that α(Vβ(3 integrin is a ligand for Thy-1 that upon binding not only restricts the growth of neurites, but also induces retraction of already existing processes by inducing Thy-1 clustering. We propose that these events participate in bi-directional astrocyte-neuron communication relevant to axonal repair after neuronal damage.

  7. The connection between metal ion affinity and ligand affinity in integrin I domains

    DEFF Research Database (Denmark)

    Vorup-Jensen, Thomas; Waldron, TT; Astrof, N

    2007-01-01

    Integrins are cell-surface heterodimeric proteins that mediate cell-cell, cell-matrix, and cell-pathogen interactions. Half of the known integrin alpha subunits contain inserted domains (I domains) that coordinate ligand through a metal ion. Although the importance of conformational changes withi...

  8. Radiosensitivity of defined populations of lymphocytes. VI. Functional, structural, and biochemical consequences of in vitro irradiation

    International Nuclear Information System (INIS)

    Anderson, R.E.; Standefer, J.C.; Scaletti, J.V.

    1977-01-01

    Single cell suspensions of BALB/c thymocytes (T cells) and nu/nu spleen cells (B cells) were exposed to 0, 50, and 500 rads and examined for topological abnormalities and alterations in surface glycoproteins and capacity to traffic normally upon transfer to syngeneic recipients. The results show that irradiated lymphocytes from both sources undergo extensive topological alterations which become more pronounced with the passage of time and which appear to precede the loss of cell viability. Viable T and B cells irradiated in vitro also fail to recirculate normally and accumulate in abnormal proportions in the spleen at the expense of the lymph nodes and gut-associated lymphoid tissues. Similarly, after a 2-hr incubation in saline at room temperature, irradiation of both T and B cells resulted in alterations in extractable surface glycoproteins. The results are consistent with the hypothesis that alterations in the rcirculation of irradiated lymphocytes are associated with alterations in the plasma membrane

  9. Role of α and β Transmembrane Domains in Integrin Clustering

    Directory of Open Access Journals (Sweden)

    Amir Shamloo

    2015-11-01

    Full Text Available Integrins are transmembrane proteins playing a crucial role in the mechanical signal transduction from the outside to the inside of a cell, and vice versa. Nevertheless, this signal transduction could not be implemented by a single protein. Rather, in order for integrins to be able to participate in signal transduction, they need to be activated and produce clusters first. As integrins consist of α- and β-subunits that are separate in the active state, studying both subunits separately is of a great importance, for, in the active state, the distance between α- and β-subunits is long enough that they do not influence one another significantly. Thus, this study aims to investigate the tendency of transmembrane domains of integrins to form homodimers. We used both Steered and MARTINI Coarse-grained molecular dynamics method to perform our simulations, mainly because of a better resolution and computational feasibility that each of these methods could provide to us. Using the Steered molecular dynamics method for α- and β-subunits, we found that the localized lipid packing prevented them from clustering. Nonetheless, the lipid packing phenomenon was found to be an artifact after investigating this process using a coarse grained (CG model. Exploiting the coarse-grained molecular dynamics simulations, we found that α- and β-subunits tend to form a stable homo-dimer.

  10. Quantitative trait loci for CD4:CD8 lymphocyte ratio are associated with risk of type 1 diabetes and HIV-1 immune control

    NARCIS (Netherlands)

    Ferreira, Manuel A. R.; Mangino, Massimo; Brumme, Chanson J.; Zhao, Zhen Zhen; Medland, Sarah E.; Wright, Margaret J.; Nyholt, Dale R.; Gordon, Scott; Campbell, Megan; McEvoy, Brian P.; Henders, Anjali; Evans, David M.; Lanchbury, Jerry S.; Pereyra, Florencia; Walker, Bruce D.; Haas, David W.; Soranzo, Nicole; Spector, Tim D.; de Bakker, Paul I. W.; Frazer, Ian H.; Montgomery, Grant W.; Martin, Nicholas G.; Agan, Brian; Agarwal, Shanu; Allen, Brady; Altidor, Sherly; Altschuler, Eric; Ambardar, Sujata; Anastos, Kathryn; Anderson, Ben; Andrady, Ushan; Angell, Teresa; Appelbaum, Jonathan; Arnold, Kathy; Arroyo, Julio; Arthur, Ernie; Barbaro, Daniel; Barrett, Tom; Barrie, William; Barthel, Vincent; Bartlett, Mary E.; Barton, Simon; Basden, Pat; Basgoz, Nesli; Bellos, Nicholas; Berger, Judith; Bernard, Annette; Bernard, Nicole; Blair, Donald; Schuitemaker, Hanneke

    2010-01-01

    Abnormal expansion or depletion of particular lymphocyte subsets is associated with clinical manifestations such as HIV progression to AIDS and autoimmune disease. We sought to identify genetic predictors of lymphocyte levels and reasoned that these may play a role in immune-related diseases. We

  11. Polyvalent integrin antagonist-decorated superparamagnetic iron oxide nanoparticles for triggering apoptosis in human leukemia cancer cells

    International Nuclear Information System (INIS)

    Say, Rıdvan; Yazar, Suzan; Uğur, Alper; Hür, Deniz; Denizli, Adil; Ersöz, Arzu

    2013-01-01

    Integrin family members are the main mediators of cell adhesion to the extracellular matrix and active as intra- and extracellular signaling molecules in a variety of processes. They bind to their ligands by interacting with short amino acid sequences, that is, RGD (arginine-glycine-aspartic acid) sequence. RGD sequences have been used to enhance cell binding to artificial surfaces, so RGD mimics have been used to block integrin binding to its ligand. Integrin–ligand interactions are dependent on divalent cations, and Mg 2+ provide higher-affinity binding to ligand for many integrins. In this study, we have designed new integrin antagonists using methacryloyl amidoaspartic acid (MAASP) monomer-conjugated silanized super paramagnetic iron oxide nanoparticles (SPIONs, the size of the nanoparticles was verified with an average size of 32.6 nm) and poly(MAASP-co-EDMA) shell-decorated silanized SPIONs. Several mechanisms have been proposed to describe uptake of modified SPIONs into the cells, including receptor-mediated endocytosis. Our aim is to bind these modified SPIONs to the integrin-mediated aspartic acid ends of MAASP monomers and block integrin binding to their ligand.

  12. The effect of acrylamide on alpha-naphthyl acetate esterase enzyme in blood circulating lymphocytes and gut associated lymphoid tissues in rats.

    Science.gov (United States)

    Yener, Y; Sur, E; Telatar, T; Oznurlu, Y

    2013-01-01

    The aim of this study is to determine the functional effects of the acrylamide (AA) administrated by oral gavage on the peripheral blood lymphocytes (PBL) and the Gut Associated Lymphoid Tissue (GALT) in male Sprague-Dawley rats using alpha-naphthyl acetate esterase (ANAE) demonstration. For this purpose, two separate experiments were performed with Sprague Dawley rats. In Experiment-I rats were gavaged with 0, 30, 45 and 60 mg/kgb.w. AA for five consecutive days and in Experiment-II rats were gavaged with 0, 125, 150, and 175 mg/kg/b.w. AA for single oral dose. Animals were sacrificed 24 h after the last treatments in both experiments by servical dislocations under ether anaesthesia. Blood samples were collected from the heart in heparinized (10 UI heparin/ml(-1) of the blood) tubes before sacrification and lymphoid tissue samples from the ileal Peyer's patches (IPPs) were taken and processed for histochemical demonstration of ANAE following the sacrification. The lymphoid follicles of the IPPs of animals given 125, 150 and 175 mg/kgb.w. AA were markedly reduced in size. Germinal centres (GCs) markedly regressed in AA-treated animals compared with those of controls. ANAE-positive lymphocyte depletion of IPPs was very prominent in the high doses AA-treated animals. In the animals treated with 30, 45, and 60 mg/kg b.w. AA, the IPPs had similar histology to those of the controls. ANAE-positive peripheral blood lymphocyte levels significantly decreased in AA exposed groups in a dose dependent manner (pAssociated Lymphoid Tissue (GALT) in rats. Copyright © 2011 Elsevier GmbH. All rights reserved.

  13. Preoperative neutrophil-lymphocyte and platelet-lymphocyte ratios as independent predictors of cervical stromal involvement in surgically treated endometrioid adenocarcinoma

    Directory of Open Access Journals (Sweden)

    Wang D

    2013-03-01

    Full Text Available Dan Wang, Jia-Xin Yang, Dong-Yan Cao, Xi-Run Wan, Feng-Zhi Feng, Hui-Fang Huang, Keng Shen, Yang Xiang Department of Obstetrics and Gynecology, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, People's Republic of China Background: The purpose of this study was to evaluate the relationship between preoperative inflammatory markers (neutrophil-lymphocyte ratio and platelet-lymphocyte ratio and cervical stromal involvement in patients with endometrioid adenocarcinoma. Methods: We studied 318 patients with endometrioid adenocarcinoma who underwent comprehensive surgical staging. We used univariate and multivariate analyses of cervical stromal involvement and receiver-operating curves to calculate optimal cutoff values for neutrophil-lymphocyte and platelet-lymphocyte ratios to predict cervical stromal involvement. Results: The presence of cervical stromal involvement was associated with neutrophil-lymphocyte ratio and platelet-lymphocyte ratio (P = 0.009 and P = 0.031, respectively. Multivariate analysis showed that higher neutrophil-lymphocyte and platelet-lymphocyte ratios independently predicted cervical stromal involvement (odds ratio 3.10, 95% confidence interval 1.10–8.76, P = 0.032, and odds ratio 5.27, 95% confidence interval 1.94–14.35, P = 0.001, respectively. At a threshold of 2.01, the neutrophil-lymphocyte ratio was 71.0% sensitive and 63.8% specific for stromal involvement; at a 172.24 threshold, the platelet-lymphocyte ratio was 48.4% sensitive and 88.9% specific. Conclusion: Preoperative neutrophil-lymphocyte and platelet-lymphocyte ratios can help identify the risk of cervical stromal involvement in patients with endometrial cancer. Evaluating these ratios may help select patients who should be particularly watched and tested for cervical stromal involvement. Keywords: neutrophil-lymphocyte ratio, platelet-lymphocyte ratio, endometrioid adenocarcinoma

  14. Beta1 integrin promotes but is not essential for metastasis of ras-myc transformed fibroblasts

    DEFF Research Database (Denmark)

    Brakebusch, C; Wennerberg, K; Krell, H W

    1999-01-01

    To investigate the role of beta1 integrin during tumor metastasis, we established a ras-myc transformed fibroblastoid cell line with a disrupted beta1 integrin gene on both alleles (GERM 11). Stable transfection of this cell line with an expression vector encoding beta1A integrin resulted in beta1A......, tumors induced by the high expressing clones 1A10 and 2F2 were markedly smaller, suggesting an inverse correlation of tumor growth and beta1 integrin expression. The metastasis potential of all three beta1 integrin-expressing GERM 11 sublines tested was significantly higher than that of the beta1......-deficient GERM 11 cells. GERM 116 tumors led in all animals to severe metastasis in lung and liver, while GERM 11 tumors induced only a few metastatic foci in the lung. Stroma of both tumors contained nidogen and high amounts of tenascin C, but only a few very low levels of fibronectin, laminin-1...

  15. Peripheral blood lymphocyte apoptosis and its relationship with thyroid function tests in adolescents with hyperthyroidism due to Graves' disease

    Science.gov (United States)

    Grywalska, Ewelina; Surdacka, Agata; Tarach, Jerzy; Klatka, Janusz; Roliński, Jacek

    2012-01-01

    Introduction Failures in apoptotic pathways can contribute to various autoimmune diseases, including autoimmune hyperthyroidism due to Graves’ disease (GD). The aim of the present research was to assess changes in the degree of peripheral blood (PB) lymphocyte apoptosis during methimazole (MMI) treatment in the group of teenage children, and to describe its relationship with thyroid function tests. Material and methods The percentage of PB apoptotic lymphocytes, assessed by the decrease in mitochondrial transmembrane potential (CMXRos staining), was measured in 30 adolescents at the time of diagnosis and after obtaining normalization of the thyroid hormone levels. Results The percentage of apoptotic lymphocytes in previously untreated patients with GD (5.16 ±2.81%) was significantly lower (p = 0.000001) than the percentage of apoptotic cells in the same group of patients after obtaining methimazole-induced euthyroidism (10.72 ±4.66%). There was a correlation between the increase of the mean percentages of apoptotic lymphocytes and the reduction of FT4 levels (R = 0.63, p < 0.0001), as well as the reduction of TT3 levels (R = 0.95, p < 0.0001). The more signs and symptoms accompanying the diagnosis of GD, the higher was the increment of the degree of lymphocyte apoptosis observed during the MMI-treatment (R = 0.74, p < 0.0000001). The methimazole dosage correlated (R = 0.85, p < 0.0001) with the percentage of apoptotic cells. Conclusions The use of methimazole in treatment of hyperthyroidism due to GD leads to an increment of apoptotic cells in PB. Higher doses of methimazole cause a higher increase of apoptotic lymphocytes. Apoptosis induction of human PB lymphocytes seems to be one of the indicators of proper hyperthyroidism treatment. PMID:23185197

  16. Age- and dose-related alteration of in vitro mixed lymphocyte culture response of blood lymphocytes from A-bomb survivors

    International Nuclear Information System (INIS)

    Akiyama, Mitoshi; Zhou, Ou-Liang; Kusunoki, Yoichiro; Kyoizumi, Seishi; Kohno, Nobuoki; Akiba, Suminori; Delongchamp, R.R.

    1988-07-01

    The responsiveness of peripheral blood lymphocytes to allogenic antigens in mixed lymphocyte culture (MLC) was measured in 139 atomic bomb survivors. The study revealed a significant decrease in MLC with increasing dose of previous radiation exposure. This decline was remarkable in the survivors who were older than 15 at the time of the bomb (ATB). The results suggest a possible relationship between the recovery of T-cell-related function and the thymic function which processes mature T-cells for the immune system. Thus it may be that, in the advanced age ATB group, the thymus function has started to involute allowing less recovery of T-cell function compared to young survivors who have adequate processing T-cell activity. (author)

  17. High Affinity vs. Native Fibronectin in the Modulation of αvβ3 Integrin Conformational Dynamics: Insights from Computational Analyses and Implications for Molecular Design.

    Directory of Open Access Journals (Sweden)

    Antonella Paladino

    2017-01-01

    Full Text Available Understanding how binding events modulate functional motions of multidomain proteins is a major issue in chemical biology. We address several aspects of this problem by analyzing the differential dynamics of αvβ3 integrin bound to wild type (wtFN10, agonist or high affinity (hFN10, antagonist mutants of fibronectin. We compare the dynamics of complexes from large-scale domain motions to inter-residue coordinated fluctuations to characterize the distinctive traits of conformational evolution and shed light on the determinants of differential αvβ3 activation induced by different FN sequences. We propose an allosteric model for ligand-based integrin modulation: the conserved integrin binding pocket anchors the ligand, while different residues on the two FN10's act as the drivers that reorganize relevant interaction networks, guiding the shift towards inactive (hFN10-bound or active states (wtFN10-bound. We discuss the implications of results for the design of integrin inhibitors.

  18. Clinical value of Pro-GRP and T lymphocyte subpopulation for the assessment of immune functions of lung cancer patients after DC-CIK biological therapy.

    Science.gov (United States)

    He, Lijie; Wang, Jing; Chang, Dandan; Lv, Dandan; Li, Haina; Zhang, Heping

    2018-02-01

    The present study investigated the aptness of assessing the levels of progastrin-releasing peptide (Pro-GRP) in addition to the T lymphocyte subpopulation in lung cancer patients prior to and after therapy for determining immune function. A total of 45 patients with lung cancer were recruited and stratified in to a non-small cell lung cancer (NSCLC) and an SCLC group. Prior to and after treatment by combined biological therapy comprising chemotherapy or chemoradiotherapy followed by three cycles of retransformation of autologous dendritic cells-cytokine-induced killer cells (DC-CIK), the peripheral blood was assessed for populations of CD3 + , CD4 + , CD8 + and regulatory T cells (Treg) by flow cytometry, and for the levels of pro-GRP, carcinoembryonic antigen, neuron-specific enolase and Cyfra 21-1. The results revealed that in NSCLC patients, CD8 + T lymphocytes and Treg populations were decreased, and that CD3 + and CD4 + T lymphocytes as well as the CD4 + /CD8 + ratio were increased after therapy; in SCLC patients, CD3 + , CD4 + and CD8 + T lymphocytes were increased, while Treg cells were decreased after treatment compared with those at baseline. In each group, Pro-GRP was decreased compared with that prior to treatment, and in the SCLC group only, an obvious negative correlation was identified between Pro-GRP and the T lymphocyte subpopulation. Furthermore, a significant correlation between Pro-GRP and Tregs was identified in each group. In conclusion, the present study revealed that the immune function of the patients was improved after biological therapy. The results suggested a significant correlation between Pro-GRP and the T lymphocyte subpopulation in SCLC patients. Detection of Pro-GRP may assist the early clinical diagnosis of SCLC and may also be used to assess the immune regulatory function of patients along with the T lymphocyte subpopulation. Biological therapy with retransformed autologous DC-CIK was indicated to enhance the specific elimination

  19. The relationship between lymphocytes activated by pokeweed mitogen and by lipopolysaccharides and their radiosensitivity

    International Nuclear Information System (INIS)

    Su Liaoyuan; Liu Fenju; Liu Keliang; Xu Changshao; Xu Yingdong; Geng Yongzhi

    1992-07-01

    Human whole blood was incubated in vitro. Lymphocytes were activated by poke-weed mitogen (PWM) and by Lipopolysaccharides (LPS). The relationship between the two kinds of lymphocytes was investigated using radioactive compound incorporation. The study showed that PWM-activated lymphocytes were able to promote the stimulating effect of LPS on B lymphocytes. The stimulating effect of PWM-activated lymphocytes was obviously decreased after they were irradiated with 10 Gy gamma rays. When PWM-activated lymphocytes and LPS-activated lymphocytes were incubated together after one of the cell populations had been exposed 10 Gy 60 Co gamma rays, the incorporation of [ 3 H] TdR was much decreased and the synergistic function disappeared, especially when the PWM-activated lymphocytes were irradiated. In cells from patients treated with 60 Co gamma rays for carcinoma of nasopharynx, the incorporation in LPS-activated lymphocytes approached normal levels while that in PWM-activated lymphocytes was reduced significantly and the stimulating effect of PWM-activated lymphocytes on LPS-activated lymphocytes was also markedly reduced. These demonstrate that PWM-activated lymphocytes have a similar function to T-helper cells and seem to be more radiosensitive than LPS-activated lymphocytes

  20. Design, synthesis and validation of integrin α2β1-targeted probe for microPET imaging of prostate cancer

    International Nuclear Information System (INIS)

    Huang, Chiun-Wei; Li, Zibo; Cai, Hancheng; Chen, Kai; Shahinian, Tony; Conti, Peter S.

    2011-01-01

    The ability of PET to aid in the diagnosis and management of recurrent and/or disseminated metastatic prostate cancer may be enhanced by the development of novel prognostic imaging probes. Accumulating experimental evidence indicates that overexpression of integrin α 2 β 1 may correlate with progression in human prostate cancer. In this study, 64 Cu-labeled integrin α 2 β 1 -targeted PET probes were designed and evaluated for the imaging of prostate cancer. DGEA peptides conjugated with a bifunctional chelator (BFC) were developed to image integrin α 2 β 1 expression with PET in a subcutaneous PC-3 xenograft model. The microPET images were reconstructed by a two-dimensional ordered subsets expectation maximum algorithm. The average radioactivity accumulation within a tumor or an organ was quantified from the multiple region of interest volumes. The PET tracer demonstrated prominent tumor uptake in the PC-3 xenograft (integrin α 2 β 1 -positive). The receptor specificity was confirmed in a blocking experiment. Moreover, the low tracer uptake in a CWR-22 tumor model (negative control) further confirmed the receptor specificity. The sarcophagine-conjugated DGEA peptide allows noninvasive imaging of tumor-associated α 2 β 1 expression, which may be a useful PET probe for evaluating the metastatic potential of prostate cancer. (orig.)

  1. Associations between immune function and air pollution among postmenopausal women living in the Puget Sound airshed

    Science.gov (United States)

    Williams, Lori A.

    Air pollution is associated with adverse health outcomes, and changes in the immune system may be intermediate steps between exposure and a clinically relevant adverse health outcome. We analyzed the associations between three different types of measures of air pollution exposure and five biomarkers of immune function among 115 overweight and obese postmenopausal women whose immunity was assessed as part of a year-long moderate exercise intervention trial. For air pollution metrics, we assessed: (1) residential proximity to major roads (freeways, major arterials and truck routes), (2) fine particulate matter(PM2.5) at the nearest monitor to the residence averaged over three time windows (3-days, 30-days and 60-days), and (3) nitrogen dioxide (NO2) modeled based on land use characteristics. Our immune biomarkers included three measures of inflammation---C-reactive protein, serum amyloid A and interleukin-6---and two measures of cellular immunity---natural killer cell cytotoxicity and T lymphocyte proliferation. We hypothesized that living near a major road, increased exposure to PM2.5 and increased exposure to NO2 would each be independently associated with increased inflammation and decreased immune function. We observed a 21% lower average natural killer cell cytotoxicity among women living within 150 meters of a major arterial road compared to other women. For PM2.5 , we observed changes in 3 of 4 indicators of lymphocyte proliferation stimulated by anti-CD3---an antibody to the T cell receptor associated with increases in 3-day averaged PM2.5. For 30-day averaged PM 2.5 and 60-day averaged PM2.5 we did not observe any statistically significant associations. We observed an increase in lymphocyte proliferation index stimulated by the plant protein phytohemagglutinin (PHA) at 1 of 2 PHA concentrations in association with modeled NO2. For the three inflammatory markers, we observed no notable associations with any of our measures of air pollution. If confirmed, our

  2. Immunophenotypic features of tumor infiltrating lymphocytes from mammary carcinomas in female dogs associated with prognostic factors and survival rates

    International Nuclear Information System (INIS)

    Estrela-Lima, Alessandra; Araújo, Márcio SS; Costa-Neto, João M; Teixeira-Carvalho, Andréa; Barrouin-Melo, Stella M; Cardoso, Sergio V; Martins-Filho, Olindo A; Serakides, Rogéria; Cassali, Geovanni D

    2010-01-01

    The immune system plays an important role in the multifactorial biologic system during the development of neoplasias. However, the involvement of the inflammatory response in the promotion/control of malignant cells is still controversial, and the cell subsets and the mechanisms involved are poorly investigated. The goal of this study was to characterize the clinical-pathological status and the immunophenotyping profile of tumor infiltrating lymphocytes and their association with the animal survival rates in canine mammary carcinomas. Fifty-one animals with mammary carcinomas, classified as carcinomas in mixed tumors-MC-BMT = 31 and carcinomas-MC = 20 were submitted to systematic clinical-pathological analysis (tumor size; presence of lymph node and pulmonary metastasis; clinical stage; histological grade; inflammatory distribution and intensity as well as the lymphocytic infiltrate intensity) and survival rates. Twenty-four animals (MC-BMT = 16 and MC = 8) were elected to the immunophenotypic study performed by flow cytometry. Data analysis demonstrated that clinical stage II-IV and histological grade was I more frequent in MC-BMT as compared to MC. Univariate analysis demonstrated that the intensity of inflammation (moderate/intense) and the proportion of CD4 + (≥ 66.7%) or CD8 + T-cells (<33.3%) were not associated with worse survival rate. Multivariate analysis demonstrated that only lymphocytic infiltrate intensity ≥ 600 (P = 0.02) remained as independent prognostic factor. Despite the clinical manifestation, the lymphocytes represented the predominant cell type in the tumor infiltrate. The percentage of T-cells was higher in animals with MC-BMT without metastasis, while the percentage of B-lymphocytes was greater in animals with metastasized MC-BMT (P < 0.05). The relative percentage of CD4 + T-cells was significantly greater in metastasized tumors (both MC-BMT and MC), (P < 0.05) while the proportion of CD8 + T-cells was higher in MC-BMT without

  3. The group B streptococcal alpha C protein binds alpha1beta1-integrin through a novel KTD motif that promotes internalization of GBS within human epithelial cells.

    Science.gov (United States)

    Bolduc, Gilles R; Madoff, Lawrence C

    2007-12-01

    Group B Streptococcus (GBS) is the leading cause of bacterial pneumonia, sepsis and meningitis among neonates and a cause of morbidity among pregnant women and immunocompromised adults. GBS epithelial cell invasion is associated with expression of alpha C protein (ACP). Loss of ACP expression results in a decrease in GBS internalization and translocation across human cervical epithelial cells (ME180). Soluble ACP and its 170 amino acid N-terminal region (NtACP), but not the repeat protein RR', bind to ME180 cells and reduce internalization of wild-type GBS to levels obtained with an ACP-deficient isogenic mutant. In the current study, ACP colocalized with alpha(1)beta(1)-integrin, resulting in integrin clustering as determined by laser scanning confocal microscopy. NtACP contains two structural domains, D1 and D2. D1 is structurally similar to fibronectin's integrin-binding region (FnIII10). D1's (KT)D146 motif is structurally similar to the FnIII10 (RG)D1495 integrin-binding motif, suggesting that ACP binds alpha(1)beta(1)-integrin via the D1 domain. The (KT)D146A mutation within soluble NtACP reduced its ability to bind alpha(1)beta(1)-integrin and inhibit GBS internalization within ME180 cells. Thus ACP binding to human epithelial cell integrins appears to contribute to GBS internalization within epithelial cells.

  4. Integrin Activation Dynamics between the RGD-binding Site and the Headpiece Hinge*

    Science.gov (United States)

    Puklin-Faucher, Eileen; Vogel, Viola

    2009-01-01

    Integrins form mechanical links between the extracellular matrix and the cytoskeleton. Although integrin activation is known to be regulated by an allosteric conformational change, which can be induced from the extracellular or intracellular end of the molecule, little is known regarding the sequence of structural events by which signals propagate between distant sites. Here, we reveal with molecular dynamics simulations of the FnIII10-bound αVβ3 integrin headpiece how the binding pocket and interdomain βA/hybrid domain hinge on the distal end of the βA domain are allosterically linked via a hydrophobic T-junction between the middle of the α1 helix and top of the α7 helix. The key results of this study are: 1) that this T-junction is induced by ligand binding and hinge opening, and thus displays bidirectionality; 2) that formation of this junction can be accelerated by ligand-mediated force; and 3) how formation of this junction is inhibited by Ca2+ in place of Mg2+ at the site adjacent to the metal ion-dependent adhesion site (“ADMIDAS”). Together with recent experimental evidence that integrin complexes can form catch bonds (i.e. become strengthened under force), as well as earlier evidence that Ca2+ at the ADMIDAS results in lower binding affinity, these simulations provide a common structural model for the dynamic process by which integrins become activated. PMID:19762919

  5. The synthesis and biological evaluation of integrin receptor targeting molecules as potential radiopharmaceuticals

    Science.gov (United States)

    Pellegrini, Paul

    This thesis reports on the synthesis, characterisation and biological evaluation of a number of metal complexes designed to interact with the alphavbeta3 integrin receptor, an important biological target that is heavily involved in angiogenesis, and thus cancer related processes. Two approaches were used to synthesise the integrin-avid targets. The first was to attach a variety of bifunctional chelators (BFC's) for the incorporation of different metal centres to a known integrin antagonist, L-748,415, developed by Merck. The BFC's used were the hydrazinonicotinamide (HYNIC) and monoamine monoamide dithiol (MAMA) systems for coordination to Tc-99m and rhenium of which was used as a characterization surrogate for the unstable Tc core. The 1,4,7,10-tetraazacyclotridecanetetraacetic acid (TRITA) BFC was attached for the inclusion of copper and lutetium. This 'conjugate' approach was designed to yield information on how the BFC and the linker length would affect the affinity for the integrin receptor. The second approach was an 'integrated' method where the chelation moiety was integral to the biologically relevant part of the molecule, which in the case of the alphavbeta3 integrin receptor, is the arginine-glycine-aspartic acid (RGD) mimicking sequence. Two complexes were created with a modified MAMA derivative placed between a benzimidazole moiety (arginine mimick) and the aspartic acid mimicking terminal carboxylic acid to see how it would affect binding while keeping the molecular weight relatively low. The molecules were tested in vitro against purified human alphavbeta3 integrin receptor protein in a solid phase receptor binding assay to evaluate their inhibition constants against a molecule of known high affinity and selectivity in [I125]L-775,219, the I125 labelled alphavbeta3 integrin antagonist. The radiolabelled analogues were also tested in vivo against the A375 human melanoma cell line transplanted into balb/c nude mice as well as Fischer rats implanted

  6. Modulation of integrin-linked kinase nucleo-cytoplasmic shuttling by ILKAP and CRM1.

    Science.gov (United States)

    Nakrieko, Kerry-Ann; Vespa, Alisa; Mason, David; Irvine, Timothy S; D'Souza, Sudhir J A; Dagnino, Lina

    2008-07-15

    Integrin-linked kinase (ILK) plays key roles in a variety of cell functions, including cell proliferation, adhesion and migration. Within the cell, ILK localizes to multiple sites, including the cytoplasm, focal adhesion complexes that mediate cell adhesion to extracellular substrates, as well as cell-cell junctions in epidermal keratinocytes. Central to understanding ILK function is the elucidation of the mechanisms that regulate its subcellular localization. We now demonstrate that ILK is imported into the nucleus through sequences in its N-terminus, via active transport mechanisms that involve nuclear pore complexes. In addition, nuclear ILK can be rapidly exported into the cytoplasm through a CRM1-dependent pathway, and its export is enhanced by the type 2C protein phosphatase ILKAP. Nuclear localization of ILK in epidermal keratinocytes is associated with increased DNA synthesis, which is sensitive to inhibition by ILKAP. Our studies demonstrate the importance for keratinocyte proliferation of ILK regulation through changes in its subcellular localization, and establish ILKAP and CRM1 as pivotal modulators of ILK subcellular distribution and activity in these cells.

  7. Integrin β4 Regulates Migratory Behavior of Keratinocytes by Determining Laminin-332 Organization*s

    Science.gov (United States)

    Sehgal, Bernd U.; DeBiase, Phillip J.; Matzno, Sumio; Chew, Teng-Leong; Claiborne, Jessica N.; Hopkinson, Susan B.; Russell, Alan; Marinkovich, M. Peter; Jones, Jonathan C. R.

    2010-01-01

    Whether α6β4 integrin regulates migration remains controversial. β4 integrin-deficient (JEB) keratinocytes display aberrant migration in that they move in circles, a behavior that mirrors the circular arrays of laminin (LM)-332 in their matrix. In contrast, wild-type keratinocytes and JEB keratinocytes, induced to express β4 integrin, assemble laminin-332 in linear tracks over which they migrate. Moreover, laminin-332-dependent migration of JEB keratinocytes along linear tracks is restored when cells are plated on wild-type keratinocyte matrix, whereas wild-type keratinocytes show rotation over circular arrays of laminn-332 in JEB keratinocyte matrix. The activities of Rac1 and the actin cytoskeleton-severing protein cofilin are low in JEB keratinocytes compared with wild-type cells but are rescued following expression of wild-type β4 integrin in JEB cells. Additionally, in wild-type keratinocytes Rac1 is complexed with α6β4 integrin. Moreover, Rac1 or cofilin inactivation induces wild-type keratinocytes to move in circles over rings of laminin-332 in their matrix. Together these data indicate that laminin-332 matrix organization is determined by the α6β4 integrin/actin cytoskeleton via Rac1/cofilin signaling. Furthermore, our results imply that the organizational state of laminin-332 is a key determinant of the motility behavior of keratinocytes, an essential element of skin wound healing and the successful invasion of epidermal-derived tumor cells. PMID:16973601

  8. Chronic lymphocytic leukemia cells are active participants in microenvironmental cross-talk

    OpenAIRE

    van Attekum, Martijn HA; Eldering, Eric; Kater, Arnon P

    2017-01-01

    The importance of the tumor microenvironment in chronic lymphocytic leukemia is widely accepted. Nevertheless, the understanding of the complex interplay between the various types of bystander cells and chronic lymphocytic leukemia cells is incomplete. Numerous studies have indicated that bystander cells provide chronic lymphocytic leukemia-supportive functions, but it has also become clear that chronic lymphocytic leukemia cells actively engage in the formation of a supportive tumor microenv...

  9. Impaired T-lymphocyte colony formation by cord blood mononuclear cells

    International Nuclear Information System (INIS)

    Herrod, H.G.; Valenski, W.R.

    1982-01-01

    When compared to adult mononuclear cells, cord blood mononuclear cells demonstrated significantly decreased T-lymphocyte colony formation (1351 +/- 643 vs 592 +/- 862, P less than 0.01). This diminished colony-forming activity did not appear to be associated with impaired responsiveness to the stimulant phytohemagglutinin or with excessive suppressor-cell activity. Irradiation reduced the colony-forming capacity of cord blood mononuclear cells more than it did that of adult mononuclear cells. Depletion of adherent cells reduced cord blood mononuclear-cell colony-forming capacity by 40%, while similar treatment reduced adult colony formation by 10%. Lymphocyte proliferation in liquid culture of cord and adult cells was minimally affected by these procedures. The colony-forming capacity of cord blood could be enhanced by the addition of irradiated adult cells (284 +/- 72 vs 752 +/- 78, P less than 0.01). This enhancement was demonstrated to be due to a soluble factor produced by a population of irradiated adult cells depleted of the OKT8+ subpopulation of lymphocytes. These results indicate that the progenitor cells of T-lymphocyte colonies in cord blood have distinct biologic characteristics when compared to colony progenitors present in adult blood. This assay may prove to be useful in our efforts to understand the differentiation of T-cell function in man

  10. Adhesive F-actin Waves: A Novel Integrin-Mediated Adhesion Complex Coupled to Ventral Actin Polymerization

    OpenAIRE

    Case, Lindsay B.; Waterman, Clare M.

    2011-01-01

    At the leading lamellipodium of migrating cells, protrusion of an Arp2/3-nucleated actin network is coupled to formation of integrin-based adhesions, suggesting that Arp2/3-mediated actin polymerization and integrin-dependent adhesion may be mechanistically linked. Arp2/3 also mediates actin polymerization in structures distinct from the lamellipodium, in "ventral F-actin waves" that propagate as spots and wavefronts along the ventral plasma membrane. Here we show that integrins engage the ex...

  11. β3 integrin promotes chemoresistance to epirubicin in MDA-MB-231 through repression of the pro-apoptotic protein, BAD

    Energy Technology Data Exchange (ETDEWEB)

    Nair, Madhumathy G.; Desai, Krisha; Prabhu, Jyothi S.; Hari, P.S.; Remacle, Jose; Sridhar, T.S., E-mail: tssridhar@sjri.res.in

    2016-08-01

    Resistance to anthracycline based chemotherapy is a major limitation in the treatment of breast cancer, particularly of the triple negative sub-type that lacks targeted therapies. Resistance that arises from tumor-stromal interaction facilitated by integrins provides the possibility of targeted disruption. In the present study, we demonstrate that integrin β3 signaling inhibits apoptosis induced by a DNA-damaging chemotherapeutic agent, epirubicin, in MDA-MB-231 breast cancer cells. Drug efflux based mechanisms do not contribute to this effect. We show that integrin β3 employs the PI3K-Akt and the MAPK pathway for enabling cell survival and proliferation. Further, our results indicate that integrin β3 helps inhibit epirubicin induced cytotoxicity by repression of the pro-apoptotic protein BAD, thus promoting an anti-apoptotic response. Myristoylated RGT peptide and a monoclonal antibody against integrin β3 brought about a reversal of this effect and chemosensitized the cells. These results identify β3 integrin signaling via repression of BAD as an important survival pathway used by breast cancer cells to evade chemotherapy induced stress. - Highlights: • Integrin β3 signaling promotes chemoresistance to epirubicin in breast cancer cells. • Integrin β3 promotes cell survival and proliferation in drug treated cells through the PI3K and MAPK pathways. • Integrin signaling helps evade drug induced cytotoxicity by repression of pro-apoptotic molecule; BAD.

  12. Recombinant Nonstructural 3 Protein, rNS3, of Hepatitis C Virus Along With Recombinant GP96 Induce IL-12, TNFα and α5integrin Expression in Antigen Presenting Cells

    Science.gov (United States)

    Hajizadeh, Mohammad Reza; Mokarram, Pooneh; Kamali sarvestani, Eskandar; Bolhassani, Azam; Mostafavi Pour, Zohreh

    2013-01-01

    Background Hepatitis C virus (HCV) infection is the main cause of chronic liver disease and to date there has been no vaccine development to prevent this infection. Among non-structural HCV proteins, NS3 protein is an excellent goal for a therapeutic vaccine, due to its large size and less variation in conserved regions. The immunogenic properties of heat shock proteins (HSPs) for instance GP96 have prompted investigations into their function as strong adjuvant to improve innate and adaptive immunity. Objectives The aim of this study was to examine additive effects of recombinant GP96 (rGP96) fragments accompanied by rNS3 on expression levels of α5integrin and pro-inflammatory cytokines, IL-12 and TNFα, in Antigen Presenting Cells (APCs). Materials and Methods Recombinant viral proteins (rNS3 and rRGD-NS3), N-terminal and C-terminal fragments of GP96 were produced and purified from E. coli in order to treat the cells; mouse spleen Dendritic Cells (DCs) and THP-1 macrophages. Results Our results showed that rNT-GP96 alone significantly increases the expression level of IL-12, TNFα and α5integrin in THP-1 macrophages and DCs, while IL-12 and TNFα expression levels were unaffected by either rNS3 or rRGD-NS3. Interestingly, the co-addition of these recombinant proteins with rNT-GP96 increased IL-12, TNFα and α5integrin expression. Pearson Correlation showed a direct association between α5integrin with IL-12 and TNF-α expression. Conclusions we have highlighted the role of rNS3 plus rNT-GP96 mediated by α5integrin in producing IL-12 and TNFα. It can be suggested that rNT-GP96 could enhance immunity characteristic of rNS3 protein via production of pro-inflammatory cytokines. PMID:24032046

  13. Integrin Beta 3 Regulates Cellular Senescence by Activating the TGF-β Pathway

    Directory of Open Access Journals (Sweden)

    Valentina Rapisarda

    2017-03-01

    Full Text Available Cellular senescence is an important in vivo mechanism that prevents the propagation of damaged cells. However, the precise mechanisms regulating senescence are not well characterized. Here, we find that ITGB3 (integrin beta 3 or β3 is regulated by the Polycomb protein CBX7. β3 expression accelerates the onset of senescence in human primary fibroblasts by activating the transforming growth factor β (TGF-β pathway in a cell-autonomous and non-cell-autonomous manner. β3 levels are dynamically increased during oncogene-induced senescence (OIS through CBX7 Polycomb regulation, and downregulation of β3 levels overrides OIS and therapy-induced senescence (TIS, independently of its ligand-binding activity. Moreover, cilengitide, an αvβ3 antagonist, has the ability to block the senescence-associated secretory phenotype (SASP without affecting proliferation. Finally, we show an increase in β3 levels in a subset of tissues during aging. Altogether, our data show that integrin β3 subunit is a marker and regulator of senescence.

  14. Detection of adult T-cell leukemia virus (ATLV) bearing lymphocytes in concentrated red blood cells derived from ATL associated antibody (ATLA-Ab) positive donors.

    Science.gov (United States)

    Morishima, Y; Ohya, K; Ueda, R; Fukuda, T

    1986-01-01

    Adult T cell leukemia associated antibody (ATLA-Ab) positive persons were screened by indirect immunofluorescence (IF) testing. Their lymphocytes were collected from concentrated red blood cells (CRC), and cultured in vitro with and without phytohemagglutinin (PHA) for 10 days. The expression of ATL virus (ATLV) positive lymphocytes during the in vitro culture was then analyzed by IF assay using mouse monoclonal antibody ATL-19 reactive to p19 core protein of ATLV. 97% of ATLA-Ab positive CRC (36 cases) demonstrated ATLV positive lymphocytes after being cultured for more than 10 days with PHA, whereas, none of ATLA-Ab negative CRC (22 cases) demonstrated ATLV positive lymphocytes. All of the 10 ATLA-Ab positive CRC that were stored for 2, 4, and 7 days contained lymphocytes which expressed ATLV after in vitro culture, while 7 of 10 CRC stored for 14 days and only 1 of 10 CRCs stored for 20 days, expressed ATLV positive lymphocytes. This data indicates that almost all of the ATLA-Ab positive blood contained ATLV positive lymphocytes, and that the in vitro appearance of these ATLV positive lymphocytes was reduced by storing the CRC for more than 14 days.

  15. Effect of interleukin-2 and methylprednisolone on in vitro transformation of uremic lymphocytes

    DEFF Research Database (Denmark)

    Langhoff, E; Ladefoged, J; Ødum, Niels

    1986-01-01

    The functional relationship in vitro between mitogen-induced lymphocyte transformation, lymphocyte response to interleukin-2 (IL-2) and steroid, and production of IL-2 was examined in patients with chronic renal failure on hemodialysis (HD) or on continuous ambulatory peritoneal dialysis (CAPD......). The lymphocyte responses to optimal stimulation with phytohemagglutinin, concanavalin A, and pokeweed mitogen were depressed in lymphocyte cultures from HD patients, while CAPD lymphocyte cultures responded normally. However, at suboptimal phytohemagglutinin stimulation both CAPD lymphocyte and HD lymphocyte...... responses were subnormal. Uremic lymphocyte cultures were more sensitive to the immunosuppressive effect of methylprednisolone. Addition of IL-2 normalized the phytohemagglutinin responses of suboptimally stimulated CAPD lymphocyte cultures and clearly improved the mitogen responses of the HD lymphocyte...

  16. Phospho-Tyrosine(s) vs. Phosphatidylinositol Binding in Shc Mediated Integrin Signaling

    OpenAIRE

    Lin, Xiaochen; Vinogradova, Olga

    2015-01-01

    The Shc adaptor protein, particularly its p52 isoform, has been identified as a primary signaling partner for the tyrosine(s)-phosphorylated cytoplasmic tails of activated ? 3 integrins. Inspired by our recent structure of the Shc PTB domain in complex with a bi-phosphorylated peptide derived from ? 3 cytoplasmic tail, we have initiated the investigation of Shc interaction with phospholipids of the membrane. We are particularly focused on PtdIns and their effects on Shc mediated integrin sign...

  17. Orphan nuclear receptor TR3/Nur77 improves wound healing by upregulating the expression of integrin β4.

    Science.gov (United States)

    Niu, Gengming; Ye, Taiyang; Qin, Liuliang; Bourbon, Pierre M; Chang, Cheng; Zhao, Shengqiang; Li, Yan; Zhou, Lei; Cui, Pengfei; Rabinovitz, Issac; Mercurio, Arthur M; Zhao, Dezheng; Zeng, Huiyan

    2015-01-01

    Tissue repair/wound healing, in which angiogenesis plays an important role, is a critical step in many diseases including chronic wound, myocardial infarction, stroke, cancer, and inflammation. Recently, we were the first to report that orphan nuclear receptor TR3/Nur77 is a critical mediator of angiogenesis and its associated microvessel permeability. Tumor growth and angiogenesis induced by VEGF-A, histamine, and serotonin are almost completely inhibited in Nur77 knockout mice. However, it is not known whether TR3/Nur77 plays any roles in wound healing. In these studies, skin wound-healing assay was performed in 3 types of genetically modified mice having various Nur77 activities. We found that ectopic induction of Nur77 in endothelial cells of mice is sufficient to improve skin wound healing. Although skin wound healing in Nur77 knockout mice is comparable to the wild-type control mice, the process is significantly delayed in the EC-Nur77-DN mice, in which a dominant negative Nur77 mutant is inducibly and specifically expressed in mouse endothelial cells. By a loss-of-function assay, we elucidate a novel feed-forward signaling pathway, integrin β4 → PI3K → Akt → FAK, by which TR3 mediates HUVEC migration. Furthermore, TR3/Nur77 regulates the expression of integrin β4 by targeting its promoter activity. In conclusion, expression of TR3/Nur77 improves wound healing by targeting integrin β4. TR3/Nur77 is a potential candidate for proangiogenic therapy. The results further suggest that TR3/Nur77 is required for pathologic angiogenesis but not for developmental/physiologic angiogenesis and that Nur77 and its family members play a redundant role in normal skin wound healing. © FASEB.

  18. [Distribution diversity of integrins and calcium channels on major human and mouse host cells of Leptospira species].

    Science.gov (United States)

    Li, Cheng-xue; Zhao, Xin; Qian, Jing; Yan, Jie

    2012-07-01

    To determine the distribution of integrins and calcium channels on major human and mouse host cells of Leptospira species. The expression of β1, β2 and β3 integrins was detected with immunofluorescence assay on the surface of human monocyte line THP-1, mouse mononuclear-macrophage-like cell line J774A.1, human vascular endothelial cell line HUVEC, mouse vascular endothelial cell EOMA, human hepatocyte line L-02, mouse hepatocyte line Hepa1-6, human renal tubular epithelial cell line HEK-293, mouse glomerular membrane epithelial cell line SV40-MES13, mouse collagen blast line NIH/3T3, human and mouse platelets. The distribution of voltage gate control calcium channels Cav3.1, Cav3.2, Cav3.3 and Cav2.3, and receptor gate calcium channels P(2)X(1), P(2)2X(2), P(2)X(3), P(2)X(4), P(2)X(5), P(2)X(6) and P(2)X(7) were determined with Western blot assay. β1 integrin proteins were positively expressed on the membrane surface of J774A.1, THP-1, HUVEC, EOMA, L-02, Hepa1-6 and HEK-239 cells as well as human and mouse platelets. β2 integrin proteins were expressed on the membrane surface of J774A.1, THP-1, HUVEC, EOMA, and NIH/3T3 cells. β3 integrin proteins were expressed on the membrane surface of J774A.1, THP-1, HUVEC, EOMA, Hepa1-6, HEK-239 and NIH/3T3 cells as well as human and mouse platelets. P(2)X(1) receptor gate calcium channel was expressed on the membrane surface of human and mouse platelets, while P(2)X(5) receptor gate calcium channel was expressed on the membrane surface of J774A.1, THP-1, L-02, Hepa1-6, HEK-239 and HUVEC cells. However, the other calcium channels were not detected on the tested cell lines or platelets. There is a large distribution diversity of integrins and calcium channel proteins on the major human and mouse host cells of Leptospira species, which may be associated with the differences of leptospira-induced injury in different host cells.

  19. A Small Molecule, Which Competes with MAdCAM-1, Activates Integrin α4β7 and Fails to Prevent Mucosal Transmission of SHIV-SF162P3.

    Directory of Open Access Journals (Sweden)

    Géraldine Arrode-Brusés

    2016-06-01

    Full Text Available Mucosal HIV-1 transmission is inefficient. However, certain viral and host characteristics may play a role in facilitating HIV acquisition and systemic expansion. Cells expressing high levels of integrin α4β7 have been implicated in favoring the transmission process and the infusion of an anti-α4β7 mAb (RM-Act-1 prior to, and during a repeated low-dose vaginal challenge (RLDC regimen with SIVmac251 reduced SIV acquisition and protected the gut-associated lymphoid tissues (GALT in the macaques that acquired SIV. α4β7 expression is required for lymphocyte trafficking to the gut lamina propria and gut inductive sites. Several therapeutic strategies that target α4β7 have been shown to be effective in treating inflammatory conditions of the intestine, such as inflammatory bowel disease (IBD. To determine if blocking α4β7 with ELN, an orally available anti-α4 small molecule, would inhibit SHIV-SF162P3 acquisition, we tested its ability to block MAdCAM-1 (α4β7 natural ligand and HIV-gp120 binding in vitro. We studied the pharmacokinetic profile of ELN after oral and vaginal delivery in macaques. Twenty-six macaques were divided into 3 groups: 9 animals were treated with ELN orally, 9 orally and vaginally and 8 were used as controls. All animals were challenged intra-vaginally with SHIV-SF162P3 using the RLDC regimen. We found that ELN did not protect macaques from SHIV acquisition although it reduced the SHIV-induced inflammatory status during the acute phase of infection. Notably, integrins can exist in different activation states and, comparing the effect of ELN and the anti-α4β7 mAb RM-Act-1 that reduced susceptibility to SIV infection, we determined that ELN induces the active conformation of α4β7, while RM-Act-1 inhibits its activation through an allosteric mechanism. These results suggest that inhibition of α4β7 activation may be necessary to reduce susceptibility to SIV/SHIV infection and highlight the complexity of anti-integrins

  20. HPW-RX40 restores anoikis sensitivity of human breast cancer cells by inhibiting integrin/FAK signaling

    Energy Technology Data Exchange (ETDEWEB)

    Chen, I-Hua; Shih, Hsin-Chu [Graduate Institute of Natural Products, Kaohsiung Medical University, Kaohsiung, Taiwan (China); Hsieh, Pei-Wen [Graduate Institute of Natural Products, School of Traditional Chinese Medicine, and Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan (China); Chang, Fang-Rong [Graduate Institute of Natural Products, Kaohsiung Medical University, Kaohsiung, Taiwan (China); Cancer Center, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan (China); Wu, Yang-Chang, E-mail: yachwu@mail.cmu.edu [School of Pharmacy, College of Pharmacy, China Medical University, Taichung, Taiwan (China); Wu, Chin-Chung, E-mail: ccwu@kmu.edu.tw [Graduate Institute of Natural Products, Kaohsiung Medical University, Kaohsiung, Taiwan (China); Department of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung 80708, Taiwan (China); Research Center for Natural Products and Drug Development, Kaohsiung Medical University, Kaohsiung, Taiwan (China)

    2015-12-01

    Anoikis is defined as apoptosis, which is induced by inappropriate cell–matrix interactions. Cancer cells with anoikis resistance tend to undergo metastasis, and this phenomenon has been reported to be associated with integrin and FAK activity. HPW-RX40 is a derivative of 3,4-methylenedioxy-β-nitrostyrene, which is known to prevent platelet aggregation by inhibition of integrin. In the present study, we investigated the effect of HPW-RX40 on an anoikis-resistant human breast cancer cell line MDA-MB-231. HPW-RX40 inhibited cell aggregation and induced cell death in suspending MDA-MB-231 cells, but had only little effect on the monolayer growth of adherent cells. Analysis of caspase activation and poly (ADP-ribose) polymerase (PARP) cleavage confirmed anoikis in HPW-RX40-treated suspending cancer cells. HPW-RX40 also affected the Bcl-2 family proteins in detached cancer cells. Furthermore, HPW-RX40 inhibited detachment-induced activation of FAK and the downstream phosphorylation of Src and paxillin, but did not affect this pathway in adherent cancer cells. We also found that the expression and activation of β1 integrin in MDA-MB-231 cells were reduced by HPW-RX40. The combination of HPW-RX40 with an EGFR inhibitor led to enhanced anoikis and inhibition of the FAK pathway in breast cancer cells. Taken together, our results suggest that HPW-RX40 restores the anoikis sensitivity in the metastatic breast cancer cells by inhibiting integrin and subsequent FAK activation, and reveal a potential strategy for prevention of tumor metastasis. - Highlights: • The β-nitrostyrene derivative, HPW-RX40, induces anoikis in human breast cancer cells. • HPW-RX40 inhibits the integrin/FAK signaling pathway. • The combination of HPW-RX40 with an EGFR inhibitor leads to enhanced anoikis. • HPW-RX40 may have a potential to prevent the spread of metastatic breast cancer.

  1. HPW-RX40 restores anoikis sensitivity of human breast cancer cells by inhibiting integrin/FAK signaling

    International Nuclear Information System (INIS)

    Chen, I-Hua; Shih, Hsin-Chu; Hsieh, Pei-Wen; Chang, Fang-Rong; Wu, Yang-Chang; Wu, Chin-Chung

    2015-01-01

    Anoikis is defined as apoptosis, which is induced by inappropriate cell–matrix interactions. Cancer cells with anoikis resistance tend to undergo metastasis, and this phenomenon has been reported to be associated with integrin and FAK activity. HPW-RX40 is a derivative of 3,4-methylenedioxy-β-nitrostyrene, which is known to prevent platelet aggregation by inhibition of integrin. In the present study, we investigated the effect of HPW-RX40 on an anoikis-resistant human breast cancer cell line MDA-MB-231. HPW-RX40 inhibited cell aggregation and induced cell death in suspending MDA-MB-231 cells, but had only little effect on the monolayer growth of adherent cells. Analysis of caspase activation and poly (ADP-ribose) polymerase (PARP) cleavage confirmed anoikis in HPW-RX40-treated suspending cancer cells. HPW-RX40 also affected the Bcl-2 family proteins in detached cancer cells. Furthermore, HPW-RX40 inhibited detachment-induced activation of FAK and the downstream phosphorylation of Src and paxillin, but did not affect this pathway in adherent cancer cells. We also found that the expression and activation of β1 integrin in MDA-MB-231 cells were reduced by HPW-RX40. The combination of HPW-RX40 with an EGFR inhibitor led to enhanced anoikis and inhibition of the FAK pathway in breast cancer cells. Taken together, our results suggest that HPW-RX40 restores the anoikis sensitivity in the metastatic breast cancer cells by inhibiting integrin and subsequent FAK activation, and reveal a potential strategy for prevention of tumor metastasis. - Highlights: • The β-nitrostyrene derivative, HPW-RX40, induces anoikis in human breast cancer cells. • HPW-RX40 inhibits the integrin/FAK signaling pathway. • The combination of HPW-RX40 with an EGFR inhibitor leads to enhanced anoikis. • HPW-RX40 may have a potential to prevent the spread of metastatic breast cancer.

  2. The Influence of Macronutrients on Splanchnic and Hepatic Lymphocytes in Aging Mice.

    Science.gov (United States)

    Le Couteur, David G; Tay, Szun S; Solon-Biet, Samantha; Bertolino, Patrick; McMahon, Aisling C; Cogger, Victoria C; Colakoglu, Feyza; Warren, Alessandra; Holmes, Andrew J; Pichaud, Nicolas; Horan, Martin; Correa, Carolina; Melvin, Richard G; Turner, Nigel; Ballard, J William O; Ruohonen, Kari; Raubenheimer, David; Simpson, Stephen J

    2015-12-01

    There is a strong association between aging, diet, and immunity. The effects of macronutrients and energy intake on splanchnic and hepatic lymphocytes were studied in 15 month old mice. The mice were ad-libitum fed 1 of 25 diets varying in the ratios and amounts of protein, carbohydrate, and fat over their lifetime. Lymphocytes in liver, spleen, Peyers patches, mesenteric lymph nodes, and inguinal lymph nodes were evaluated using flow cytometry. Low protein intake reversed aging changes in splenic CD4 and CD8 T cells, CD4:CD8 T cell ratio, memory/effector CD4 T cells and naïve CD4 T cells. A similar influence of total caloric intake in these ad-libitum fed mice was not apparent. Protein intake also influenced hepatic NK cells and B cells, while protein to carbohydrate ratio influenced hepatic NKT cells. Hepatosteatosis was associated with increased energy and fat intake and changes in hepatic Tregs, effector/memory T, and NK cells. Hepatic NK cells were also associated with body fat, glucose tolerance, and leptin levels while hepatic Tregs were associated with hydrogen peroxide production by hepatic mitochondria. Dietary macronutrients, particularly protein, influence splanchnic lymphocytes in old age, with downstream associations with mitochondrial function, liver pathology, and obesity-related phenotype. © The Author 2014. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  3. Length of hospitalization is associated with selected biomarkers (albumin and lymphocytes) and with co-morbidities: study on 4000 patients.

    Science.gov (United States)

    Pontiroli, Antonio E; Loreggian, Lara; Rovati, Marco P L; De Patto, Elena; Folini, Laura; Raveglia, Federico; De Simone, Matilde; Baisi, Alessandro; Cioffi, Ugo

    2017-01-01

    Low albumin levels and low lymphocyte counts are intra hospital conditions that exert a negative influence on prognosis, healing and length of hospitalization. The study aimed to analyze the correlation between low blood levels of albumin, low lymphocytes, and length of stay. The secondary aim was to identify other co-morbidities associated with prolonged hospital stay. Retrospective pilot study was conducted by analyzing anamnestic and biochemical data, related to 4038 patients admitted to ten wards of Hospital San Paolo (Milan), collected from July 1 st 2012 to December 31 st 2012. A statistical analysis was carried out using the Correlation method, Multivariate Analysis and Regression. Lymphocyte count and co-morbidities were evaluated in the whole cohort, albumin levels in 1437 patients. In the whole sample, low albumin levels and low lymphocyte counts were directly correlated to longer hospitalizations. The stratification of the results by department and diagnosis suggests that there is a higher correlation in certain subpopulations, and albumin shows a greater correlation with length of stay than lymphocytes. Also advanced age, high platelets, type of diagnosis, male gender and emergency admission led to longer hospitalizations. A routine check of albumin, lymphocytes and a spectrum of significant variables can provide precious information which can eventually lead to a shorter hospital stay. Knowledge of the general health status of a patient and the possibility to estimate his/her length of hospital stay are essential information for Clinical Governance, and for the improvement of internal services of hospitals on a large scale.

  4. Long-lived, high-strength states of ICAM-1 bonds to beta2 integrin, II

    DEFF Research Database (Denmark)

    Kinoshita, Koji; Leung, Andrew; Simon, Scott

    2010-01-01

    Using single-molecule force spectroscopy to probe ICAM-1 interactions with recombinant alphaLbeta2 immobilized on microspheres and beta2 integrin on neutrophils, we quantified an impressive hierarchy of long-lived, high-strength states of the integrin bond, which start from basal levels with acti......Using single-molecule force spectroscopy to probe ICAM-1 interactions with recombinant alphaLbeta2 immobilized on microspheres and beta2 integrin on neutrophils, we quantified an impressive hierarchy of long-lived, high-strength states of the integrin bond, which start from basal levels......-out and outside-in signaling in neutrophils on the lifetimes and mechanical strengths of ICAM-1 bonds to beta2 integrin on the cell surface. Even though ICAM-1 bonds to recombinant alphaLbeta2 on microspheres in Mg2+ or Mn2+ can live for long periods of time under slow pulling, here we show that stimulation...... of neutrophils in Mg2+ plus the chemokine IL-8 (i.e., inside-out signaling) induces several-hundred-fold longer lifetimes for ICAM-1 attachments to LFA-1, creating strong bonds at very slow pulling speeds where none are perceived in Mg2+ or Mn2+ alone. Similar changes are observed with outside-in signaling, i...

  5. Integrin-linked kinase is required for TGF-β1 induction of dermal myofibroblast differentiation.

    Science.gov (United States)

    Vi, Linda; de Lasa, Cristina; DiGuglielmo, Gianni M; Dagnino, Lina

    2011-03-01

    Cutaneous repair after injury requires activation of resident dermal fibroblasts and their transition to myofibroblasts. The key stimuli for myofibroblast formation are activation of transforming growth factor-β (TGF-β) receptors and mechanotransduction mediated by integrins and associated proteins. We investigated the role of integrin-linked kinase (ILK) in TGF-β1 induction of dermal fibroblast transition to myofibroblasts. ILK-deficient fibroblasts treated with TGF-β1 exhibited attenuation of Smad 2 and 3 phosphorylation, accompanied by impaired transcriptional activation of Smad targets, such as α-smooth muscle actin. These alterations were not limited to Smad-associated TGF-β1 responses, as stimulation of noncanonical mitogen-activated protein kinase pathways by this growth factor was also diminished in the absence of ILK. ILK-deficient fibroblasts exhibited abnormalities in the actin cytoskeleton, and did not form supermature focal adhesions or contractile F-actin stress fibers, indicating a severe impairment in their capacity to differentiate into myofibroblasts. These defects extended to the inability of cells to contract extracellular matrices when embedded in collagen lattices. We conclude that ILK is necessary to transduce signals implicated in the transition of dermal fibroblasts to myofibroblasts originating from matrix substrates and TGF-β1.

  6. Levels of α7 integrin and laminin-α2 are increased following prednisone treatment in the mdx mouse and GRMD dog models of Duchenne muscular dystrophy

    Directory of Open Access Journals (Sweden)

    Ryan D. Wuebbles

    2013-09-01

    Duchenne muscular dystrophy (DMD is a fatal neuromuscular disease for which there is no cure and limited treatment options. Prednisone is currently the first line treatment option for DMD and studies have demonstrated that it improves muscle strength. Although prednisone has been used for the treatment of DMD for decades, the mechanism of action of this drug remains unclear. Recent studies have shown that the α7β1 integrin is a major modifier of disease progression in mouse models of DMD and is therefore a target for drug-based therapies. In this study we examined whether prednisone increased α7β1 integrin levels in mdx mouse and GRMD dog models and myogenic cells from humans with DMD. Our results show that prednisone promotes an increase in α7 integrin protein in cultured myogenic cells and in the muscle of mdx and GRMD animal models of DMD. The prednisone-mediated increase in α7 integrin was associated with increased laminin-α2 in prednisone-treated dystrophin-deficient muscle. Together, our results suggest that prednisone acts in part through increased merosin in the muscle basal lamina and through sarcolemmal stabilization of α7β1 integrin in dystrophin-deficient muscle. These results indicate that therapies that target an increase in muscle α7β1 integrin, its signaling pathways and/or laminin could be therapeutic in DMD.

  7. Human U87 astrocytoma cell invasion induced by interaction of βig-h3 with integrin α5β1 involves calpain-2.

    Directory of Open Access Journals (Sweden)

    Jie Ma

    Full Text Available It is known that βig-h3 is involved in the invasive process of many types of tumors, but its mechanism in glioma cells has not been fully clarified. Using immunofluorescent double-staining and confocal imaging analysis, and co-immunoprecipitation assays, we found that βig-h3 co-localized with integrin α5β1 in U87 cells. We sought to elucidate the function of this interaction by performing cell invasion assays and gelatin zymography experiments. We found that siRNA knockdowns of βig-h3 and calpain-2 impaired cell invasion and MMP secretion. Moreover, βig-h3, integrins and calpain-2 are known to be regulated by Ca(2+, and they are also involved in tumor cell invasion. Therefore, we further investigated if calpain-2 was relevant to βig-h3-integrin α5β1 interaction to affect U87 cell invasion. Our data showed that βig-h3 co-localized with integrin α5β1 to enhance the invasion of U87 cells, and that calpain-2, is involved in this process, acting as a downstream molecule.

  8. Failure of pulmonary clearance of Rhodococcus equi infection in CD4+ T-lymphocyte-deficient transgenic mice.

    OpenAIRE

    Kanaly, S T; Hines, S A; Palmer, G H

    1993-01-01

    Pulmonary clearance of Rhodococcus equi requires functional T lymphocytes. In this study, CD8+ T-lymphocyte-deficient transgenic mice cleared virulent R. equi from the lungs while infection in CD4+ T-lymphocyte-deficient transgenic mice persisted. Although both CD4+ and CD8+ T cells function early in pulmonary defense against R. equi, clearance is dependent on CD4+ T lymphocytes.

  9. Is total lymphocyte count related to nutritional markers in hospitalized older adults?

    Directory of Open Access Journals (Sweden)

    Vânia Aparecida LEANDRO-MERHI

    Full Text Available ABSTRACT BACKGROUND Older patients are commonly malnourished during hospital stay, and a high prevalence of malnutrition is found in hospitalized patients aged more than 65 years. OBJECTIVE To investigate whether total lymphocyte count is related to other nutritional markers in hospitalized older adults. METHODS Hospitalized older adults (N=131 were recruited for a cross-sectional study. Their nutritional status was assessed by the Nutritional Risk Screening (NRS, anthropometry, and total lymphocyte count. The statistical analyses included the chi-square test, Fisher's exact test, and Mann-Whitney test. Spearman's linear correlation coefficient determined whether total lymphocyte count was correlated with the nutritional markers. Multiple linear regression determined the parameters associated with lymphocyte count. The significance level was set at 5%. RESULTS According to the NRS, 41.2% of the patients were at nutritional risk, and 36% had mild or moderate depletion according to total lymphocyte count. Total lymphocyte count was weakly correlated with mid-upper arm circumference (r=0.20507; triceps skinfold thickness (r=0.29036, and length of hospital stay (r= -0.21518. Total lymphocyte count in different NRS categories differed significantly: older adults who were not at nutritional risk had higher mean and median total lymphocyte count ( P =0.0245. Multiple regression analysis showed that higher lymphocyte counts were associated with higher triceps skinfold thicknesses and no nutritional risk according to the NRS. CONCLUSION Total lymphocyte count was correlated with mid-upper arm circumference, triceps skinfold thickness, and nutritional risk according to the NRS. In multiple regression the combined factors that remained associated with lymphocyte count were NRS and triceps skinfold thickness. Therefore, total lymphocyte count may be considered a nutritional marker. Other studies should confirm these findings.

  10. A new 500 kb haplotype associated with high CD8+ T-lymphocyte numbers predicts a less severe expression of hereditary hemochromatosis

    Directory of Open Access Journals (Sweden)

    Mascarenhas Cláudia

    2008-11-01

    Full Text Available Abstract Background Hereditary Hemochromatosis(HH is a common genetic disorder of iron overload where the large majority of patients are homozygous for one ancestral mutation in the HFE gene. In spite of this remarkable genetic homogeneity, the condition is clinically heterogeneous, varying from a severe disease to an asymptomatic phenotype with only abnormal biochemical parameters. The recent recognition of the variable penetrance of the HH mutation in different large population studies demands the need to search for new modifiers of its phenotypic expression. The present study follows previous observations that MHC class-I linked genetic markers, associated with the setting of CD8+ T-lymphocyte numbers, could be clinically relevant modifiers of the phenotypic expression in HH, and aimed to find new markers that could be used as more reliable prognostic variables. Methods Haplotype analysis, including seven genetic markers within a 1 Mb region around the microsatellite D6S105 was performed in a group of 56 previously characterized C282Y homozygous Portuguese patients. Parameters analyzed in this study were total body iron stores, clinical manifestations related with HH and immunological parameters (total lymphocyte numbers, CD4+ and CD8+ T-lymphocyte numbers. An independent group of 10 C282Y homozygous patients from Vancouver, Canada, were also included in this study and analyzed for the same parameters. Results A highly conserved ancestral haplotype defined by the SNP markers PGBD1-A, ZNF193-A, ZNF165-T (designated as A-A-T was found associated with both abnormally low CD8+ T-lymphocyte numbers and the development of a severe clinical expression of HH. In a small proportion of patients, another conserved haplotype defined by the SNP markers PGBD1-G, ZNF193-G, ZNF165-G (designated as G-G-G was found associated with high CD8+ T-lymphocyte numbers and a milder clinical expression. Remarkably, the two conserved haplotypes defined in Portuguese

  11. The β3-Integrin Binding Protein β3-Endonexin Is a Novel Negative Regulator of Hypoxia-Inducible Factor-1

    Science.gov (United States)

    Kračun, Damir; Rieß, Florian; Kanchev, Ivan; Gawaz, Meinrad

    2014-01-01

    Abstract Aims: Integrins are multifunctional heterodimeric adhesion receptors that mediate the attachment between a cell and the extracellular matrix or other surrounding cells. In endothelial cells, integrins can modulate cell migration and motility. In particular, β3-integrin is expressed in angiogenic vessels. Signal transduction by β3-integrins requires the recruitment of intracellular signaling molecules. β3-endonexin is a highly spliced molecule that has been identified as a β3-integrin binding protein. β3-endonexin isoforms are expressed in endothelial cells and have been suggested to act as shuttle proteins between the membrane and the nucleus. However, their functional role in angiogenesis is unclear. In this study, we investigated whether β3-endonexin isoforms are involved in endothelial angiogenic processes under hypoxia. Results: The overexpression of β3-endonexin isoforms decreased endothelial proliferation and tube formation under hypoxia, while the depletion of β3-endonexin by RNAi promoted angiogenic responses in vitro and in vivo. In hypoxia, β3-endonexin accumulated in the nucleus, and prevention of this response by depletion of β3-endonexin increased hypoxic activation and induction of the hypoxia-inducible factor (HIF)-1 and its target genes VEGF and PAI-1. β3-endonexin diminished nuclear factor kappa B (NFκB) activation and decreased NFκB binding to the HIF-1α promoter under hypoxia, subsequently diminishing NFκB-dependent transcription of HIF-1α under hypoxia. Innovation: Our results indicate for the first time that the overexpression of β3-endonexin can decrease hypoxic induction and activation of HIF-1α and can prevent hypoxic endothelial proliferation and angiogenic responses. Conclusion: β3-endonexin can act as a novel anti-angiogenic factor specifically in the response to hypoxia due to its negative impact on the activation of HIF-1. Antioxid. Redox Signal. 20, 1964–1976. PMID:24386901

  12. Radiation effects on lymphocytes

    International Nuclear Information System (INIS)

    Roser, B.

    1976-01-01

    This review of the ontogeny of lymphocyte populations concentrates on sites of production, rates of production, and the factors governing the differentiation and longevity of the various lymphocyte pools. The physiology of the lymphocyte pools is described with particular emphasis on recirculation from blood to lymph through lymphoid tissues. The separate routes of recirculation of both thymus-derived and nonthymus-derived lymphocytes and the possible anatomical sites and mechanisms of lymphocyte cooperation are discussed. Radiation effects on lymphocyte populations are divided into two sections. First, the effects of whole-body irradiation on the total lymphocyte pools are discussed including the differential effects of irradiation on T lymphocytes, B lymphocytes, lymphoblasts, and plasma cells. The differential sensitivity of various types of immune response is correlated, where possible, with the differential sensitivity of the lymphocyte types involved. Second, experimental attempts to selectively deplete discrete subpopulations of the total lymphocyte pools, e.g., recirculating cells, are briefly discussed with particular emphasis on studies on the effects of the localization of radionuclides in lymphoid tissue

  13. The functional interactions between CD98, beta 1-integrins, and CD147 in the induction of U937 homotypic aggregation

    Czech Academy of Sciences Publication Activity Database

    Cho, J. Y.; Fox, D. A.; Hořejší, Václav; Sagawa, K.; Skubitz, K. M.; Katz, D. R.; Chain, B.

    2001-01-01

    Roč. 98, č. 2 (2001), s. 374-382 ISSN 0006-4971 R&D Projects: GA ČR GA310/99/0349 Institutional research plan: CEZ:AV0Z5052915 Keywords : integrin * CD98 * CD147 Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 9.273, year: 2001

  14. Skin-associated lymphoid tissues (SALT): origins and functions

    International Nuclear Information System (INIS)

    Streilein, J.W.

    1983-01-01

    The skin has an unusual set of immunologic requirements. It is confronted by a specialized set of pathogenic organisms and environmental chemicals that represent a distinctive spectrum of antigenic specificities. Skin is subjected to physicochemical stresses such as irradiation with ultraviolet light that alter dramatically its immunologic properties. It is proposed that nature has provided skin with a unique collection of lymphoid cells, reticular cells, and organized lymphoid organs to deal with these special demands. Evidence in favor of the existence of skin-associated lymphoid tissues (SALT) includes (1) the cutaneous microenvironment is capable on its own of accepting, processing, and presenting nominal antigen; (2) strategically located peripheral lymph nodes are able to accept immunogenic signals derived from skin; (3) subsets of T lymphocytes display differential affinity for skin and its associated peripheral nodes; and (4) acquisition of this affinity by T cells is determined at least in part by differentiation signals received in situ from resident cutaneous cells. Responsibility for the establishment and integration of SALT rests with keratinocytes, Langerhans cells, and immunocompetent lymphocytes, each of which contributes uniquely to the synthesis. Together they provide skin with immune surveillance that effectively prejudices against the development of cutaneous neoplasms and persistent infection with intracellular pathogens. In patients who have been under long-term immunosuppressive therapy, the large majority of nonlymphoid malignancies arise within the skin, rather than other types of tissues. These data suggest that immune surveillance, once thought to be an immune defense operative in all somatic tissues, is a specialized immune function dedicated to the skin and mediated by SALT

  15. Evidence for a prolonged role of alpha 4 integrin throughout active experimental allergic encephalomyelitis.

    Science.gov (United States)

    Keszthelyi, E; Karlik, S; Hyduk, S; Rice, G P; Gordon, G; Yednock, T; Horner, H

    1996-10-01

    The leukocyte integrin receptor, alpha 4 beta 1, and its endothelial cell ligand, vascular cell adhesion molecule 1, appear to be of critical importance in the leukocyte trafficking that accompanies CNS damage in experimental allergic encephalomyelitis (EAE). In this study, the persistence of the role for alpha 4 beta 1/VCAM-1 in EAE was established by observing antibody-mediated disease reversal up to 1 month following disease onset. Limited treatment with a monoclonal antibody against alpha 4 integrin, GG5/3, resulted in a significant decrease in both clinical and histopathologic signs. This was not observed in isotype control experiments. In the latter phase of progressive disease, widespread demyelination occurred in the animals that did not respond to 6 days of anti-alpha 4 treatment. These results demonstrate an essential role for alpha 4 beta 1 interactions throughout active EAE and illustrate the difference between reversible clinical deficits caused by edema and irreversible deficits associated with demyelination.

  16. α6β1- and αV-integrins are required for long-term self-renewal of murine embryonic stem cells in the absence of LIF.

    Science.gov (United States)

    Cattavarayane, Sandhanakrishnan; Palovuori, Riitta; Tanjore Ramanathan, Jayendrakishore; Manninen, Aki

    2015-02-27

    The growth properties and self-renewal capacity of embryonic stem (ES) cells are regulated by their immediate microenvironment such as the extracellular matrix (ECM). Integrins, a central family of cellular ECM receptors, have been implicated in these processes but their specific role in ES cell self-renewal remains unclear. Here we have studied the effects of different ECM substrates and integrins in mouse ES cells in the absence of Leukemia Inhibitory Factor (LIF) using short-term assays as well as long-term cultures. Removal of LIF from ES cell culture medium induced morphological differentiation of ES cells into polarized epistem cell-like cells. These cells maintained epithelial morphology and expression of key stemness markers for at least 10 passages in the absence of LIF when cultured on laminin, fibronectin or collagen IV substrates. The specific functional roles of α6-, αV- and β1-integrin subunits were dissected using stable lentivirus-mediated RNAi methodology. β1-integrins were required for ES cell survival in long-term cultures and for the maintenance of stem cell marker expression. Inhibition of α6-integrin expression compromised self-renewal on collagen while αV-integrins were required for robust ES cell adhesion on laminin. Analysis of the stemness marker expression revealed subtle differences between α6- and αV-depleted ES cells but the expression of both was required for optimal self-renewal in long-term ES cell cultures. In the absence of LIF, long-term ES cell cultures adapt an epistem cell-like epithelial phenotype and retain the expression of multiple stem cell markers. Long-term maintenance of such self-renewing cultures depends on the expression of β1-, α6- and αV-integrins.

  17. A single disulfide bond disruption in the β3 integrin subunit promotes thiol/disulfide exchange, a molecular dynamics study.

    Directory of Open Access Journals (Sweden)

    Lihie Levin

    Full Text Available The integrins are a family of membrane receptors that attach a cell to its surrounding and play a crucial function in cell signaling. The combination of internal and external stimuli alters a folded non-active state of these proteins to an extended active configuration. The β3 subunit of the platelet αIIbβ3 integrin is made of well-structured domains rich in disulfide bonds. During the activation process some of the disulfides are re-shuffled by a mechanism requiring partial reduction of some of these bonds; any disruption in this mechanism can lead to inherent blood clotting diseases. In the present study we employed Molecular Dynamics simulations for tracing the sequence of structural fluctuations initiated by a single cysteine mutation in the β3 subunit of the receptor. These simulations showed that in-silico protein mutants exhibit major conformational deformations leading to possible disulfide exchange reactions. We suggest that any mutation that prevents Cys560 from reacting with one of the Cys(567-Cys(581 bonded pair, thus disrupting its ability to participate in a disulfide exchange reaction, will damage the activation mechanism of the integrin. This suggestion is in full agreement with previously published experiments. Furthermore, we suggest that rearrangement of disulfide bonds could be a part of a natural cascade of thiol/disulfide exchange reactions in the αIIbβ3 integrin, which are essential for the native activation process.

  18. VANGL2 interacts with integrin αv to regulate matrix metalloproteinase activity and cell adhesion to the extracellular matrix.

    Science.gov (United States)

    Jessen, Tammy N; Jessen, Jason R

    2017-12-15

    Planar cell polarity (PCP) proteins are implicated in a variety of morphogenetic processes including embryonic cell migration and potentially cancer progression. During zebrafish gastrulation, the transmembrane protein Vang-like 2 (VANGL2) is required for PCP and directed cell migration. These cell behaviors occur in the context of a fibrillar extracellular matrix (ECM). While it is thought that interactions with the ECM regulate cell migration, it is unclear how PCP proteins such as VANGL2 influence these events. Using an in vitro cell culture model system, we previously showed that human VANGL2 negatively regulates membrane type-1 matrix metalloproteinase (MMP14) and activation of secreted matrix metalloproteinase 2 (MMP2). Here, we investigated the functional relationship between VANGL2, integrin αvβ3, and MMP2 activation. We provide evidence that VANGL2 regulates cell surface integrin αvβ3 expression and adhesion to fibronectin, laminin, and vitronectin. Inhibition of MMP14/MMP2 activity suppressed the cell adhesion defect in VANGL2 knockdown cells. Furthermore, our data show that MMP14 and integrin αv are required for increased proteolysis by VANGL2 knockdown cells. Lastly, we have identified integrin αvβ3 as a novel VANGL2 binding partner. Together, these findings begin to dissect the molecular underpinnings of how VANGL2 regulates MMP activity and cell adhesion to the ECM. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  19. The effects of low dose radiation (LDR) on lymphocytes

    International Nuclear Information System (INIS)

    Su Liaoyuan; Du Zeji; Tian Hailin; Zhao Yujie; Zou Huawei; Zhou Jianhua; Kong Xiangrong; Zhang Jianhua; Shen Wei

    2001-01-01

    LDR could stimulate lymphocyte transformation for adults, children and infants. The effect of LDR on lymphocytes in malnourished children was lower, but higher on lymphocytes in cord blood. The effect of LDR on CD 4 + cells in adult persons was higher than that on CD + cells. NK cells were radioresistant. The stimulative effect of LDR on NK activity in tumor patients was lower than that in normal individuals. For the mice with tumors, LDR could increase the ratio of L 3 T 4 cells in blood, spleen and the number of cytotoxic T cells in the tumors. Extracellular fluid of the lymphocytes operated by LDR could also stimulate the lymphocyte transformation. The preliminary LDR could decrease the injuries to macromolecules, membrane antigens and chromosomes in lymphocytes which were induced by high dose radiation. The LDR- induced protein might be found from mouse spleen cells, and this protein could increase immune function in human and animals

  20. Cloning and characterization of the human integrin β6 gene promoter.

    Directory of Open Access Journals (Sweden)

    Mingyan Xu

    Full Text Available The integrin β6 (ITGB6 gene, which encodes the limiting subunit of the integrin αvβ6 heterodimer, plays an important role in wound healing and carcinogenesis. The mechanism underlying ITGB6 regulation, including the identification of DNA elements and cognate transcription factors responsible for basic transcription of human ITGB6 gene, remains unknown. This report describes the cloning and characterization of the human ITGB6 promoter. Using 5'-RACE (rapid amplification of cDNA ends analysis, the transcriptional initiation site was identified. Promoter deletion analysis identified and functionally validated a TATA box located in the region -24 to -18 base pairs upstream of the ITGB6 promoter. The regulatory elements for transcription of the ITGB6 gene were predominantly located -289 to -150 from the ITGB6 promoter and contained putative binding sites for transcription factors such as STAT3 and C/EBPα. Using chromatin immunoprecipitation assays, this study has demonstrated, for the first time, that transcription factors STAT3 and C/EBPα are involved in the positive regulation of ITGB6 transcription in oral squamous cell carcinoma cells. These findings have important implications for unraveling the mechanism of abnormal ITGB6 activation in tissue remodeling and tumorigenesis.

  1. Apigenin inhibits HGF-promoted invasive growth and metastasis involving blocking PI3K/Akt pathway and β4 integrin function in MDA-MB-231 breast cancer cells

    International Nuclear Information System (INIS)

    Lee, W.-J.; Chen, W.-K.; Wang, C.-J.; Lin, W.-L.; Tseng, T.-H.

    2008-01-01

    Hepatocyte growth factor (HGF) and its receptor, Met, known to control invasive growth program have recently been shown to play crucial roles in the survival of breast cancer patients. The diet-derived flavonoids have been reported to possess anti-invasion properties; however, knowledge on the pharmacological and molecular mechanisms in suppressing HGF/Met-mediated tumor invasion and metastasis is poorly understood. In our preliminary study, we use HGF as an invasive inducer to investigate the effect of flavonoids including apigenin, naringenin, genistein and kaempferol on HGF-dependent invasive growth of MDA-MB-231 human breast cancer cells. Results show that apigenin presents the most potent anti-migration and anti-invasion properties by Boyden chamber assay. Furthermore, apigenin represses the HGF-induced cell motility and scattering and inhibits the HGF-promoted cell migration and invasion in a dose-dependent manner. The effect of apigenin on HGF-induced signaling activation involving invasive growth was evaluated by immunoblotting analysis, it shows that apigenin blocks the HGF-induced Akt phosphorylation but not Met, ERK, and JNK phosphorylation. In addition to MDA-MB-231 cells, apigenin exhibits inhibitory effect on HGF-induced Akt phosphorylation in hepatoma SK-Hep1 cells and lung carcinoma A549 cells. By indirect immunofluorescence microscopy assay, apigenin inhibits the HGF-induced clustering of β4 integrin at actin-rich adhesive site and lamellipodia through PI3K-dependent manner. Treatment of apigenin inhibited HGF-stimulated integrin β4 function including cell-matrix adhesion and cell-endothelial cells adhesion in MDA-MB-231 cells. By Akt-siRNA transfection analysis, it confirmed that apigenin inhibited HGF-promoted invasive growth involving blocking PI3K/Akt pathway. Finally, we evaluated the effect of apigenin on HGF-promoted metastasis by lung colonization of tumor cells in nude mice and organ metastasis of tumor cells in chick embryo. By

  2. Integrin inhibitor (Cilengitide) as radiosensitization strategy for malignant tumors

    International Nuclear Information System (INIS)

    Silva, Felipe Henrique de Souza

    2017-01-01

    Radiotherapy is effective in tumor control, but several tumors have molecular characteristics that lead to radioresistance and possible posttreatment recurrence. Many tumors have overexpression of integrin receptors. Integrins play a central role in growth, motility, regulation of adhesion and survival, leading to increased proliferation, invasion and metastasis of tumors, making these receptors excellent targets for the development of new therapies. Studies have shown that inhibiting the interaction of matrix proteins with integrin receptors may increase the cytotoxic effect of ionizing radiation by demonstrating the radiosensitizing potential of combination therapy in tumoral lines. Cilengitide an inhibitor of integrins receptors α Vβ3 and αVβ5 stands out for its great antitumor potential against gliomas. Thus, the combination of ionizing radiation with cilengitide is an alternative therapeutic strategy. However, the effect of this combination is little studied in Glioblastomas (U87 and T98) and not studied in melanoma (UACC). The objective of this study was to evaluate the radiosensitising potential of the RGD molecule cilengitida by means of the combined treatment with gamma radiation in different tumor lines, as well as to compare the effect of this combination therapy with cisplatin, a molecule already used in clinical practice. Our panel of tumor cell lines was composed of U87 (wild-type p53 malignant glioblastoma) T98 (malignant glioblastoma mutant p53), MCF7 (mammary carcinoma) and UACC (melanoma). The radiosensitizer effect of cilengitide was evaluated by the quantification of metabolic cell viability through the MTT assay. Inhibition of colony formation was investigated in clonogenicity assays. The flow cytometer was used to investigate cell cycle distribution and the type of cell death induced. We observed that in all cell lines examined, cilengitida promoted detachment, metabolic alterations and reduction of proliferation, as well as alteration of

  3. Progresses in optimization strategy for radiolabeled molecular probes targeting integrin αvβ3

    International Nuclear Information System (INIS)

    Chen Haojun; Wu Hua

    2012-01-01

    Tumor angiogenesis is critical in the growth, invasion and metastasis of malignant tumors. The integrins, which express on many types of tumor cells and activated vascular endothelial cells, play an important role in regulation of the tumor angiogenesis. RGD peptide, which contains Arg-Gly-Asp sequence, binds specifically to integrin α v β 3 . Therefore, the radiolabeled RGD peptides may have broad application prospects in radionuclide imaging and therapy. Major research interests include the selection of radionuclides, modification and improvement of RGD structures. In this article, we give a review on research progresses in optimization strategy for radiolabeled molecular probes targeting integrin α v β 3 . (authors)

  4. Biometric indices of recirculating lymphocytes after acute and chronic gamma-irradiation

    International Nuclear Information System (INIS)

    Kalinin, E.V.

    1978-01-01

    The karyometry method was used to study the distribution of mature lymphocytes of lymphatic organs and peripheral blood among classes of nuclear volumes. Radiation injury was accompanied by a selection of populations of short-lived lymphocytes with very big nuclei the content of which was function of cumulative radiation dose. The number of small lymphocytes dependend on the phase of the radiation reaction

  5. The Neutrophil/Lymphocyte Ratio at Diagnosis Is Significantly Associated with Survival in Metastatic Pancreatic Cancer Patients

    Directory of Open Access Journals (Sweden)

    Matteo Piciucchi

    2017-03-01

    Full Text Available Different inflammation-based scores such as the neutrophil/lymphocyte ratio (NLR, the Odonera Prognostic Nutritional Index (PNI, the Glasgow Prognostic Score, the platelet/lymphocyte ratio, and the C-reactive protein/albumin ratio have been found to be significantly associated with pancreatic cancer (PDAC prognosis. However, most studies have investigated patients undergoing surgery, and few of them have compared these scores. We aimed at evaluating the association between inflammatory-based scores and PDAC prognosis. In a single center cohort study, inflammatory-based scores were assessed at diagnosis and their prognostic relevance as well as that of clinic-pathological variables were evaluated through multiple logistic regression and survival probability analysis. In 206 patients, age, male sex, tumor size, presence of distant metastasis, access to chemotherapy, and an NLR > 5 but not other scores were associated with overall survival (OS at multivariate analysis. Patients with an NLR < 5 had a median survival of 12 months compared to 4 months in those with an NLR > 5. In the 81 patients with distant metastasis at diagnosis, an NLR > 5 resulted in the only variable significantly associated with survival. Among patients with metastatic disease who received chemotherapy, the median survival was 3 months in patients with an NLR > 5 and 7 months in those with an NLR < 5. The NLR might drive therapeutic options in PDAC patients, especially in the setting of metastatic disease.

  6. Development of T Lymphocytes in the Nasal-associated Lymphoid Tissue (NALT from Growing Wistar Rats

    Directory of Open Access Journals (Sweden)

    Gustavo A. Sosa

    2004-01-01

    Full Text Available The aim of the present report was to study the development of several T-lymphocyte subsets in the nasal-associated lymphoid tissue (NALT of growing Wistar rats. CD5+ and CD4+ lymphocytes gradually increased with age. A predominance of CD8α+ over CD4+ T cells was found from 7 to 45 days but from 45 to 60 days of age T helper cells outnumbered the cytotoxic subpopulation. The majority of CD8+ T lymphocytes expressed the heterodimeric isoform. The most relevant findings by immunohistochemistry are: (1 the predominance of TCRγδ+ and CD8α+ cells at 7 days postpartum over all the other T-cell subpopulations; and (2 that TCRγβ+ outnumbered TCRαβ+ T cells from 7 to 45 days postpartum whereas αβ T cells predominated in 45- and 60-day-old rats. Besides, cytometric studies have shown that the percentages of TCRγ+, CD8+, as well as the population coexpressing both phenotypes (TCRγδ+CD8α+, were significantly higher in rats at 7 days postpartum when compared to 60 day-old rats. In the present study, the finding of a high number of γδ+ and CD8+ T cells early in NALT development may indicate the importance of these subpopulations in the protection of the nasal mucosa in suckling and weaning Wistar rats.

  7. Role of the beta1-integrin cytoplasmic tail in mediating invasin-promoted internalization of Yersinia

    DEFF Research Database (Denmark)

    Gustavsson, Anna; Armulik, Annika; Brakebusch, Cord

    2002-01-01

    Invasin of Yersinia pseudotuberculosis binds to beta1-integrins on host cells and triggers internalization of the bacterium. To elucidate the mechanism behind the beta1-integrin-mediated internalization of Yersinia, a beta1-integrin-deficient cell line, GD25, transfected with wild-type beta1A, beta......1B or different mutants of the beta1A subunit was used. Both beta1A and beta1B bound to invasin-expressing bacteria, but only beta1A was able to mediate internalization of the bacteria. The cytoplasmic region of beta1A, differing from beta1B, contains two NPXY motifs surrounding a double threonine...... noted that cells affected in bacterial internalization exhibited reduced spreading capability when seeded onto invasin, suggesting a correlation between the internalization of invasin-expressing bacteria and invasin-induced spreading. Likewise, integrins defective in forming peripheral focal complex...

  8. Discoidin domain receptor 1 is activated independently of beta(1) integrin

    DEFF Research Database (Denmark)

    Vogel, W; Brakebusch, C; Fässler, R

    2000-01-01

    independent of the epidermal growth factor (EGF) receptor. In cells that endogenously express both DDR1 and the EGF receptor, stimulation with EGF does not induce DDR activation. Third, we detected full DDR1 activation after collagen stimulation in cells that have been treated with blocking antibodies...... for alpha(2)beta(1) integrin or in cells with a targeted deletion of the beta(1) integrin gene. Finally, we show that overexpression of dominant negative DDR1 in the myoblast cell line C2C12 blocks cellular differentiation and the formation of myofibers....

  9. Lymphocytes as a neural probe : potential for studying psychiatric disorders

    NARCIS (Netherlands)

    Gladkevich, A; Kauffman, HF; Korf, J

    There is an increasing body evidence pointing to a close integration between the central nervous system (CNS) and immunological functions with lymphocytes playing therein a central role. The authors provide arguments to consider blood lymphocytes as a convenient probe of-an albeit-limited number of

  10. Impact of lymphocytic thyroiditis on incidence of pathological incidental thyroid carcinoma.

    Science.gov (United States)

    Farrell, Eric; Heffron, Cynthia; Murphy, Matthew; O'Leary, Gerard; Sheahan, Patrick

    2017-01-01

    The purpose of this study was to investigate the impact of lymphocytic thyroiditis on incidence of incidental thyroid cancers. We conducted a retrospective review of 713 consecutive patients who underwent thyroidectomies. Incidental thyroid cancer was defined as an unexpected cancer discovered on pathological examination outside the index nodule undergoing preoperative cytology. We excluded 65 cases because of preoperative diagnosis of thyroid cancer, and 68 because of nonincidental cancer within the index nodule. Among the remaining 580 cases, there were 43 cases (7.4%) of incidental thyroid cancers. Incidental thyroid cancers were significantly associated with moderate/severe lymphocytic thyroiditis (relative risk = 2.5; p = .03). Sixteen of 56 patients with moderate/severe lymphocytic thyroiditis had Graves' disease, none of whom had incidental thyroid cancer. The risk of incidental thyroid cancer associated with moderate/severe lymphocytic thyroiditis was significantly higher in non-Graves' than patients with Graves' disease (p = .05). The risk of incidental thyroid cancer is significantly increased in patients with moderate/severe lymphocytic thyroiditis. Moderate/severe lymphocytic thyroiditis associated with Graves' disease seems to have a lower risk of incidental thyroid cancer. © 2016 Wiley Periodicals, Inc. Head Neck 39: 122-127, 2017. © 2016 Wiley Periodicals, Inc.

  11. Adenylate cyclase toxin promotes internalisation of integrins and raft components and decreases macrophage adhesion capacity.

    Directory of Open Access Journals (Sweden)

    César Martín

    Full Text Available Bordetella pertussis, the bacterium that causes whooping cough, secretes an adenylate cyclase toxin (ACT that must be post-translationally palmitoylated in the bacterium cytosol to be active. The toxin targets phagocytes expressing the CD11b/CD18 integrin receptor. It delivers a catalytic adenylate cyclase domain into the target cell cytosol producing a rapid increase of intracellular cAMP concentration that suppresses bactericidal functions of the phagocyte. ACT also induces calcium fluxes into target cells. Biochemical, biophysical and cell biology approaches have been applied here to show evidence that ACT and integrin molecules, along with other raft components, are rapidly internalized by the macrophages in a toxin-induced calcium rise-dependent process. The toxin-triggered internalisation events occur through two different routes of entry, chlorpromazine-sensitive receptor-mediated endocytosis and clathrin-independent internalisation, maybe acting in parallel. ACT locates into raft-like domains, and is internalised, also in cells devoid of receptor. Altogether our results suggest that adenylate cyclase toxin, and maybe other homologous pathogenic toxins from the RTX (Repeats in Toxin family to which ACT belongs, may be endowed with an intrinsic capacity to, directly and efficiently, insert into raft-like domains, promoting there its multiple activities. One direct consequence of the integrin removal from the cell surface of the macrophages is the hampering of their adhesion ability, a fundamental property in the immune response of the leukocytes that could be instrumental in the pathogenesis of Bordetella pertussis.

  12. Adenylate cyclase toxin promotes internalisation of integrins and raft components and decreases macrophage adhesion capacity.

    Science.gov (United States)

    Martín, César; Uribe, Kepa B; Gómez-Bilbao, Geraxane; Ostolaza, Helena

    2011-02-23

    Bordetella pertussis, the bacterium that causes whooping cough, secretes an adenylate cyclase toxin (ACT) that must be post-translationally palmitoylated in the bacterium cytosol to be active. The toxin targets phagocytes expressing the CD11b/CD18 integrin receptor. It delivers a catalytic adenylate cyclase domain into the target cell cytosol producing a rapid increase of intracellular cAMP concentration that suppresses bactericidal functions of the phagocyte. ACT also induces calcium fluxes into target cells. Biochemical, biophysical and cell biology approaches have been applied here to show evidence that ACT and integrin molecules, along with other raft components, are rapidly internalized by the macrophages in a toxin-induced calcium rise-dependent process. The toxin-triggered internalisation events occur through two different routes of entry, chlorpromazine-sensitive receptor-mediated endocytosis and clathrin-independent internalisation, maybe acting in parallel. ACT locates into raft-like domains, and is internalised, also in cells devoid of receptor. Altogether our results suggest that adenylate cyclase toxin, and maybe other homologous pathogenic toxins from the RTX (Repeats in Toxin) family to which ACT belongs, may be endowed with an intrinsic capacity to, directly and efficiently, insert into raft-like domains, promoting there its multiple activities. One direct consequence of the integrin removal from the cell surface of the macrophages is the hampering of their adhesion ability, a fundamental property in the immune response of the leukocytes that could be instrumental in the pathogenesis of Bordetella pertussis.

  13. Proliferative responses of blood mononuclear cells (BMNC) in a cohort of elderly humans: role of lymphocyte phenotype and cytokine production

    DEFF Research Database (Denmark)

    Bruunsgaard, H.; Pedersen, Agnes Nadelmann; Schroll, M.

    2000-01-01

    Age-related impaired T cell function is associated with increased mortality risk. The purpose of the present study was therefore to identify factors associated with the age-related decreased phytohaemagglutinin (PHA)-induced proliferative response of lymphocytes in a cohort of 174 81-year...

  14. Radiosensitivity of peripheral blood lymphocytes in autoimmune disease

    Energy Technology Data Exchange (ETDEWEB)

    Harris, G [Kennedy Inst. of Rheumatology, London (UK). Div. of Experimental Pathology; Cramp, W A; Edwards, J C; George, A M; Sabovljev, S A; Hart, L; Hughes, G R.V. [Hammersmith Hospital, London (UK); Denman, A M [Northwich Park Hospital, Harrow (UK); Yatvin, M B [Wisconsin Clinical Cancer Center, Madison (USA)

    1985-06-01

    The proliferation of peripheral blood lymphocytes, cultured with Con A, can be inhibited by ionizing radiation. Lymphocytes from patients with conditions associated with autoimmunity, such as rheumatoid arthritis, systemic lupus erythematosus and polymyositis, are more radiosensitive than those from healthy volunteers or patients with conditions not associated with autoimmunity. Nuclear material isolated from the lymphocytes of patients with autoimmune diseases is, on average, lighter in density than the nuclear material from most healthy controls. This difference in density is not related to increased sensitivity to ionizing radiation but the degree of post-irradiation change in density (lightening) is proportional to the initial density, i.e. more dense nuclear material always shows a greater upward shift after radiation. The recovery of pre-irradiation density of nuclear material, 1 h after radiation exposure, taken as an indication of DNA repair, correlates with the radiosensitivity of lymphocyte proliferation (Con A response); failure to return to pre-irradiation density being associated with increased sensitivity of proliferative response. These results require extension but, taken with previously reported studied of the effects of DNA methylating agents, support the idea that DNA damage and its defective repair could be important in the aetio-pathogenesis of autoimmune disease.

  15. Short-term effects of regional irradiation on lymphocytes, T lymphocytes and eosinophils

    International Nuclear Information System (INIS)

    Chazarin, C.; Roche, H.; Bugat, R.; Pris, F.

    1983-01-01

    Twenty-three cancer patients treated only by regional irradiation were studied. Radiotherapy was delivered to the pelvis in 14 patients and to the mediastinum in 9. T lymphocytes were evaluated with the Jondal technique. Before treatment, lymphocyte counts were identical in patients and control. Decreases in total lymphocytes and T lymphocytes became significant in both groups after 40 Gy. Significant rises in eosinophil counts were found only after abdominal irradiation and seemed unrelated to variations in lymphocyte counts [fr

  16. Covisualization in living onion cells of putative integrin, putative spectrin, actin, putative intermediate filaments, and other proteins at the cell membrane and in an endomembrane sheath

    Science.gov (United States)

    Reuzeau, C.; Doolittle, K. W.; McNally, J. G.; Pickard, B. G.; Evans, M. L. (Principal Investigator)

    1997-01-01

    Covisualizations with wide-field computational optical-sectioning microscopy of living epidermal cells of the onion bulb scale have evidenced two major new cellular features. First, a sheath of cytoskeletal elements clads the endomembrane system. Similar elements clad the inner faces of punctate plasmalemmal sites interpreted as plasmalemmal control centers. One component of the endomembrane sheath and plasmalemmal control center cladding is anti-genicity-recognized by two injected antibodies against animal spectrin. Immunoblots of separated epidermal protein also showed bands recognized by these antibodies. Injected phalloidin identified F-actin with the same cellular distribution pattern, as did antibodies against intermediate-filament protein and other cytoskeletal elements known from animal cells. Injection of general protein stains demonstrated the abundance of endomembrane sheath protein. Second, the endomembrane system, like the plasmalemmal puncta, contains antigen recognized by an anti-beta 1 integrin injected into the cytoplasm. Previously, immunoblots of separated epidermal protein were shown to have a major band recognized both by this antibody prepared against a peptide representing the cytosolic region of beta 1 integrin and an antibody against the matrix region of beta 1 integrin. The latter antiboby also identified puncta at the external face of protoplasts. It is proposed that integrin and associated transmembrane proteins secure the endomembrane sheath and transmit signals between it and the lumen or matrix of the endoplasmic reticulum and organellar matrices. This function is comparable to that proposed for such transmembrane linkers in the plasmalemmal control centers, which also appear to bind cytoskeleton and a host of related molecules and transmit signals between them and the wall matrix. It is at the plasmalemmal control centers that the endoplasmic reticulum, a major component of the endomembrane system, attaches to the plasma membrane.

  17. beta1 integrin maintains integrity of the embryonic neocortical stem cell niche.

    Directory of Open Access Journals (Sweden)

    Karine Loulier

    2009-08-01

    Full Text Available During embryogenesis, the neural stem cells (NSC of the developing cerebral cortex are located in the ventricular zone (VZ lining the cerebral ventricles. They exhibit apical and basal processes that contact the ventricular surface and the pial basement membrane, respectively. This unique architecture is important for VZ physical integrity and fate determination of NSC daughter cells. In addition, the shorter apical process is critical for interkinetic nuclear migration (INM, which enables VZ cell mitoses at the ventricular surface. Despite their importance, the mechanisms required for NSC adhesion to the ventricle are poorly understood. We have shown previously that one class of candidate adhesion molecules, laminins, are present in the ventricular region and that their integrin receptors are expressed by NSC. However, prior studies only demonstrate a role for their interaction in the attachment of the basal process to the overlying pial basement membrane. Here we use antibody-blocking and genetic experiments to reveal an additional and novel requirement for laminin/integrin interactions in apical process adhesion and NSC regulation. Transient abrogation of integrin binding and signalling using blocking antibodies to specifically target the ventricular region in utero results in abnormal INM and alterations in the orientation of NSC divisions. We found that these defects were also observed in laminin alpha2 deficient mice. More detailed analyses using a multidisciplinary approach to analyse stem cell behaviour by expression of fluorescent transgenes and multiphoton time-lapse imaging revealed that the transient embryonic disruption of laminin/integrin signalling at the VZ surface resulted in apical process detachment from the ventricular surface, dystrophic radial glia fibers, and substantial layering defects in the postnatal neocortex. Collectively, these data reveal novel roles for the laminin/integrin interaction in anchoring embryonic NSCs

  18. [Immunologic indexes, enzyme status of lymphocytes and functional activity of blood neutrophils in children with infectious mononucleosis caused by Epstein-Barr virus].

    Science.gov (United States)

    Kurtasova, L M; Tolstikova, A E; Savchenko, A A

    2013-01-01

    Explore the immunological parameters, levels of activity of NAD(P)-dependent dehydrogenases lymphocytes, interferon status parameters, phagocytic activity and chemiluminescence response of neutrophils in the blood of children in the acute phase of infectious mononucleosis caused by the Epstein-Barr virus. 65 children at the age of 4-6 years old with infectious mononucleosis caused by EBV in acute phase were observed. Such indexes as cell-mediated, humoral and interferon immunity, NAD(P)-depended dehydrogenases activity in blood lymphocyte, phagocytes activity, levels of spontaneous and induced chemiluminescence ofperipheral blood neutrophils were studied. Children with EVB-infection have immunophenotype spectrum changes and changes of enzymes status of blood lymphocytes against the increasing in leucocytes and the useful increasing in lymphocytes. The useful increasing in IgA, IgM, IgG contenting in serum blood were found. The decreasing of spontaneous production of IFN alpha and the decreasing of induced production of IFNalpha, IFNgamma were determined. The breach of phagocytes activity and chemiluminescent response of blood neutrophils were found. The children in the acute phase of infectious mononucleosis caused by the Epstein-Barr virus, there are changes in the immune status, changes the activity of NAD(P)-dependent dehydrogenases in blood lymphocytes, marked changes in functional and metabolic state of peripheral blood neutrophils.

  19. Metabolites related to renal function, immune activation, and carbamylation are associated with muscle composition in older adults.

    Science.gov (United States)

    Lustgarten, Michael S; Fielding, Roger A

    2017-12-15

    Reduced skeletal muscle density in older adults is associated with insulin resistance, decreased physical function, and an increased all-cause mortality risk. To elucidate mechanisms that may underlie the maintenance of skeletal muscle density, we conducted a secondary analysis of previously published muscle composition and serum metabolomic data in 73 older adults (average age, 78y). Multivariable-adjusted linear regression was used to examine associations between 321 metabolites with muscle composition, defined as the ratio between normal density (NDM) with low density (LDM) thigh muscle cross sectional area (NDM/LDM). Sixty metabolites were significantly (p≤0.05 and qMetabolites that were significantly associated with muscle composition were then tested for their association with circulating markers of renal function (blood urea nitrogen, creatinine, uric acid), and with the immune response (neutrophils/lymphocytes) and activation (kynurenine/tryptophan). 43 significant NDM/LDM metabolites (including urea) were co-associated with at least 1 marker of renal function; 23 of these metabolites have been previously identified as uremic solutes. The neutrophil/lymphocyte ratio was significantly associated with NDM/LDM (β±SE: -0.3±0.1, p=0.01, q=0.04). 35 significant NDM/LDM metabolites were co-associated with immune activation. Carbamylation (defined as homocitrulline/lysine) was identified as a pathway that may link renal function and immune activation with muscle composition, as 29 significant NDM/LDM metabolites were co-associated with homocitrulline/lysine, with at least 2 markers of renal function, and with kynurenine/tryptophan. When considering that elevated urea and uremic metabolites have been linked with an increased systemic microbial burden, that antimicrobial defense can be reduced in the presence of carbamylation, and that adipocytes can promote host defense, we propose the novel hypothesis that the age-related increase in adipogenesis within muscle

  20. Immunohistochemical study of integrin α₅β₁, fibronectin, and Bcl-2 in normal oral mucosa, inflammatory fibroepithelial hyperplasia, oral epithelial dysplasia, and oral squamous cell carcinoma.

    Science.gov (United States)

    Núñez, Manuel Antonio Gordón; de Matos, Felipe Rodrigues; Freitas, Roseana de Almeida; Galvão, Hébel Cavalcanti

    2013-07-01

    The objective of this study was to compare the immunoexpression of integrin α₅β₁, fibronectin, and the Bcl-2 protein in normal oral mucosa (NOM), inflammatory fibroepithelial hyperplasia (IFH), oral epithelial dysplasia (OED), and oral squamous cell carcinoma (OSCC). Eleven cases of NOM, 16 IFH, 20 OED, and 27 OSCC were selected for analysis of the immunoexpression of integrin α₅β₁, fibronectin, and bcl-2 protein. There was an association between the intensity and location of the integrin α₅β₁ expression, especially in the OSCC, that 48.1% of cases showed weak immunoreactivity and 40.7% in the suprabasal layer (P < 0.05). There was an association between the pattern and distribution of fibronectin expression in basement membrane, where 90% of NOM showed a pattern of linear continuous and 80% of OED exhibited focal distribution (P < 0.05). The fibronectin expression in connective tissue was predominantly intense with an association of staining pattern among the different specimens, where 37% of OSCC showed a reticular pattern (P < 0.05). There was an association of bcl-2 protein among the types of specimens, especially in IFH and OSCC, where 100% of the cases exhibited scores 1 of staining (P < 0.05). Within this context, the interaction of integrin α₅β₁ with its main ligand in the extracellular matrix, fibronectin, is suggested to influence the survival of tumor cells and to favor their proliferation by modulating apoptosis through the upregulation of antiapoptotic proteins or the suppression of apoptotic mediators.

  1. Sjogren syndrome complicated by mucosa-associated lymphoid tissue lymphoma and lymphocytic interstitial pneumonia

    Directory of Open Access Journals (Sweden)

    Fatma eAhmed

    2015-08-01

    Full Text Available Sjogren Syndrome (SS is an autoimmune disease with exocrine glands dysfunction and multiorgan involvement. It is associated with increased risk of lymphoproliferative disorders, especially B-cell marginal zone lymphoma. While the role of F-18 Flurodoxyglucose position emission tomography/CT (F-18 FDG PET/CT for evaluation of lymphoma has been established, its use in patients with a chronic history of SS to evaluate for possible lymphoproliferative disorders or multiorgan involvement is limited. We present a case of chronic SS in which F-18 FDG PET/CT demonstrated FDG avid intraparotid and cervical lymph nodes pathologically proven to be Mucosa-associated lymphoid tissue (MALT lymphoma. In addition, the patient had bibasilar cystic changes consistent with lymphocytic interstitial pneumonia (LIP.

  2. A complex of α6 integrin and E-cadherin drives liver metastasis of colorectal cancer cells through hepatic angiopoietin-like 6.

    Science.gov (United States)

    Marchiò, Serena; Soster, Marco; Cardaci, Sabrina; Muratore, Andrea; Bartolini, Alice; Barone, Vanessa; Ribero, Dario; Monti, Maria; Bovino, Paola; Sun, Jessica; Giavazzi, Raffaella; Asioli, Sofia; Cassoni, Paola; Capussotti, Lorenzo; Pucci, Piero; Bugatti, Antonella; Rusnati, Marco; Pasqualini, Renata; Arap, Wadih; Bussolino, Federico

    2012-11-01

    Homing of colorectal cancer (CRC) cells to the liver is a non-random process driven by a crosstalk between tumour cells and components of the host tissue. Here we report the isolation of a liver metastasis-specific peptide ligand (CGIYRLRSC) that binds a complex of E-cadherin and α(6) integrin on the surface of CRC cells. We identify angiopoietin-like 6 protein as a peptide-mimicked natural ligand enriched in hepatic blood vessels of CRC patients. We demonstrate that an interaction between hepatic angiopoietin-like 6 and tumoural α(6) integrin/E-cadherin drives liver homing and colonization by CRC cells, and that CGIYRLRSC inhibits liver metastasis through interference with this ligand/receptor system. Our results indicate a mechanism for metastasis whereby a soluble factor accumulated in normal vessels functions as a specific ligand for circulating cancer cells. Consistently, we show that high amounts of coexpressed α(6) integrin and E-cadherin in primary tumours represent a poor prognostic factor for patients with advanced CRC. Copyright © 2012 The Authors. Published by John Wiley and Sons, Ltd on behalf of EMBO.

  3. Neutrophil–lymphocyte ratio is associated with low high-density lipoprotein cholesterol in healthy young men

    Directory of Open Access Journals (Sweden)

    Duran Tok

    2014-04-01

    Full Text Available Objective: It has been reported that the neutrophil–lymphocyte ratio is significantly elevated in patients with low high-density lipoprotein cholesterol (<35 mg/dL. But in this study, some patients had hypertension that may have affected the neutrophil–lymphocyte ratio. This study consisted of 1274 asymptomatic healthy young men. In contrast with the previous study, we investigated the neutrophil–lymphocyte ratio in healthy young men with low high-density lipoprotein cholesterol compared with controls. Methods: We studied 1274 asymptomatic young males (military personnel screening who underwent routine health check-up. Of them, 102 subjects had low high-density lipoprotein cholesterol. Results: The neutrophil–lymphocyte ratio was significantly higher among the men with low high-density lipoprotein cholesterol than that of the control group (P < 0.001. Conclusion: We conclude that the neutrophil–lymphocyte ratio is significantly elevated in asymptomatic healthy young men with low high-density lipoprotein cholesterol compared with control participants.

  4. Distribution of cyclophilin B-binding sites in the subsets of human peripheral blood lymphocytes.

    Science.gov (United States)

    Denys, A; Allain, F; Foxwell, B; Spik, G

    1997-08-01

    Cyclophilin B (CyPB) is a cyclosporin A (CsA)-binding protein, mainly associated with the secretory pathway and released in biological fluids. We have recently demonstrated that both free CyPB and CyPB-CsA complex specifically bind to peripheral blood T lymphocytes and are internalized. These results suggest that CyPB might promote the targeting of the drug into sensitive cells. Peripheral blood lymphocytes are subdivided in several populations according to their biological functions and sensitivity to CsA. We have investigated the binding of CyPB to these different subsets using a CyPB derivatized by fluorescein through its single cysteine which retains its binding properties. We have confirmed that only T cells were involved in the interaction with CyPB. The ligand binding was found to be heterogeneously distributed on the different T-cell subsets and surface-bound CyPB was mainly associated with the CD4-positive cells. No significant difference was noted between the CD45RA and CD45RO subsets, demonstrating that CyPB-binding sites were equally distributed between native and memory T cells. CD3 stimulation of T lymphocytes led to a decrease in the CyPB-binding capacity, that may be explained by a down-regulation of the CyPB-receptor expression upon T-cell activation. Finally, we demonstrated that CyPB-receptor-positive cells, isolated on CyPB sulphydryl-coupled affinity matrices, are more sensitive to CyPB-complexed CsA than mixed peripheral blood lymphocytes, suggesting that CyPB potentiates CsA activity through the binding of the complex. Taken together, our results demonstrate that CyPB-binding sites are mainly associated with resting cells of the helper T lymphocyte, and that CyPB might modulate the distribution of CsA through the drug targeting to sensitive cells.

  5. Integrin αβ3-Targeted Imaging of Lung Cancer

    Directory of Open Access Journals (Sweden)

    Xiaoyuan Chen

    2005-03-01

    Full Text Available A series of radiolabeled cyclic arginine-glycineaspartic acid (RGD peptide ligands for cell adhesion molecule integrin αβ3-targeted tumor angiogenesis targeting are being developed in our laboratory. In this study, this effort continues by applying a positron emitter 64Cu-labeled PEGylated dimeric RGD peptide radiotracer 64Cu-DOTA-PEG-E[c(RGDyK]2 for lung cancer imaging. The PEGylated RGD peptide indicated integrin αβ3 avidity, but the PEGylation reduced the receptor binding affinity of this ligand compared to the unmodified RGD dimer. The radiotracer revealed rapid blood clearance and predominant renal clearance route. The minimum nonspecific activity accumulation in normal lung tissue and heart rendered high-quality orthotopic lung cancer tumor images, enabling clear demarcation of both the primary tumor at the upper lobe of the left lung, as well as metastases in the mediastinum, contralateral lung, diaphragm. As a comparison, fluorodeoxyglucose (FDG scans on the same mice were only able to identify the primary tumor, with the metastatic lesions masked by intense cardiac uptake and high lung background. 64Cu-DOTA-PEGE[c(RGDyK]2 is an excellent positron emission tomography (PET tracer for integrin-positive tumor imaging. Further studies to improve the receptor binding affinity of the tracer and subsequently to increase the magnitude of tumor uptake without comprising the favorable in vivo kinetics are currently in progress.

  6. Mixed Fibronectin-Derived Peptides Conjugated to a Chitosan Matrix Effectively Promotes Biological Activities through Integrins, α4β1, α5β1, αvβ3, and Syndecan

    Directory of Open Access Journals (Sweden)

    Hozumi Kentaro

    2016-11-01

    Full Text Available Mimicking the biological function of the extracellular matrix is an approach to developing cell adhesive biomaterials. The RGD peptide, derived from fibronectin (Fn, mainly binds to integrin αvβ3 and has been widely used as a cell adhesive peptide on various biomaterials. However, cell adhesion to Fn is thought to be mediated by several integrin subtypes and syndecans. In this study, we synthesized an RGD-containing peptide (FIB1 and four integrin α4β1-binding-related motif-containing peptides (LDV, IDAPS, KLDAPT, and PRARI and constructed peptide-chitosan matrices. The FIB1-chitosan matrix promoted human dermal fibroblast (HDF attachment, and the C-terminal elongated PRARI (ePRARI-C-conjugated chitosan matrix significantly promoted HDF attachment through integrin α4β1 and syndecan binding. Next, we constructed a mixed ePRARI-C- and FIB1-chitosan matrix to develop a Fn mimetic biomaterial. The mixed ePRARI-C/FIB1-chitosan matrix promoted significantly better cell attachment and neurite outgrowth compared to those of either ePRARI-C- or FIB1-chitosan matrices. HDF adhesion to the ePRARI-C/FIB1-chitosan matrix was mediated by integrin, α4β1, α5β1, and αvβ3, similar to HDF adhesion to Fn. These data suggest that an ePRARI-C/FIB1-chitosan matrix can be used as a tool to analyze the multiple functions of Fn and can serve as a Fn-mimetic biomaterial.

  7. The Adenovirus Type 3 Dodecahedron's RGD Loop Comprises an HSPG Binding Site That Influences Integrin Binding

    Directory of Open Access Journals (Sweden)

    E. Gout

    2010-01-01

    Full Text Available Human type 3 adenovirus dodecahedron (a virus like particle made of twelve penton bases features the ability to enter cells through Heparan Sulphate Proteoglycans (HSPGs and integrins interaction and is used as a versatile vector to deliver DNA or proteins. Cryo-EM reconstruction of the pseudoviral particle with Heparan Sulphate (HS oligosaccharide shows an extradensity on the RGD loop. A set of mutants was designed to study the respective roles of the RGD sequence (RGE mutant and of a basic sequence located just downstream. Results showed that the RGE mutant binding to the HS deficient CHO-2241 cells was abolished and unexpectedly, mutation of the basic sequence (KQKR to AQAS dramatically decreased integrin recognition by the viral pseudoparticle. This basic sequence is thus involved in integrin docking, showing a close interplay between HSPGs and integrin receptors.

  8. Aminopenicillin-associated exanthem: lymphocyte transformation testing revisited.

    Science.gov (United States)

    Trautmann, A; Seitz, C S; Stoevesandt, J; Kerstan, A

    2014-12-01

    The lymphocyte transformation test (LTT) has been promoted as in-vitro test for diagnosis of drug hypersensitivity. For determination of statistical LTT sensitivity, series of patients with clinically uniform reactions followed by complete drug hypersensitivity work-up are mandatory. Assessment of LTT specificity requires control patients who tolerated exposure to the drug studied. To prospectively determine the diagnostic value of the LTT in a clinically and diagnostically well-defined series of patients. Patients with exanthematous skin eruptions after ampicillin (AMP) intake were included in this study. After exclusion or confirmation of delayed-onset allergic AMP hypersensitivity by skin and provocation testing, two independent LTTs were performed: one standard LTT and a modified LTT with additional anti-CD3/anti-CD28 monoclonal antibody stimulation. By testing, delayed-onset allergic AMP hypersensitivity was diagnosed in 11 patients and definitely ruled out in 26. The standard LTT reached a diagnostic sensitivity of 54.5% while the modified LTT yielded 72.7%. However, the methodical test modification resulted in a decline of specificity from 92.3% (standard LTT) to 76.9%. In cases of AMP-associated exanthems, the diagnostic value of the LTT compared with routine allergy testing is limited. When evaluating such exanthems, provocation testing remains the gold standard. Delayed reading of intradermal skin tests remains most useful to avoid positive provocation reactions. © 2014 John Wiley & Sons Ltd.

  9. Fibronectin-bound α5β1 integrins sense load and signal to reinforce adhesion in less than a second

    Science.gov (United States)

    Strohmeyer, Nico; Bharadwaj, Mitasha; Costell, Mercedes; Fässler, Reinhard; Müller, Daniel J.

    2017-12-01

    Integrin-mediated mechanosensing of the extracellular environment allows cells to control adhesion and signalling. Whether cells sense and respond to force immediately upon ligand-binding is unknown. Here, we report that during adhesion initiation, fibroblasts respond to mechanical load by strengthening integrin-mediated adhesion to fibronectin (FN) in a biphasic manner. In the first phase, which depends on talin and kindlin as well as on the actin nucleators Arp2/3 and mDia, FN-engaged α5β1 integrins activate focal adhesion kinase (FAK) and c-Src in less than 0.5 s to steeply strengthen α5β1- and αV-class integrin-mediated adhesion. When the mechanical load exceeds a certain threshold, fibroblasts decrease adhesion and initiate the second phase, which is characterized by less steep adhesion strengthening. This unique, biphasic cellular adhesion response is mediated by α5β1 integrins, which form catch bonds with FN and signal to FN-binding integrins to reinforce cell adhesion much before visible adhesion clusters are formed.

  10. Oxycodone Self-Administration Induces Alterations in Expression of Integrin, Semaphorin and Ephrin Genes in the Mouse Striatum

    Directory of Open Access Journals (Sweden)

    Vadim Yuferov

    2018-06-01

    Full Text Available Oxycodone is one a commonly used medication for pain, and is also a widely abused prescription opioid, like other short-acting MOPr agonists. Neurochemical and structural adaptations in brain following chronic MOPr-agonist administration are thought to underlie pathogenesis and persistence of opiate addiction. Many axon guidance molecules, such as integrins, semaphorins, and ephrins may contribute to oxycodone-induced neuroadaptations through alterations in axon-target connections and synaptogenesis, that may be implicated in the behaviors associated with opiate addiction. However, little is known about this important area. The aim of this study is to investigate alterations in expression of selected integrin, semaphorin, ephrins, netrin, and slit genes in the nucleus accumbens (NAc and caudate putamen (CPu of mice following extended 14-day oxycodone self-administration (SA, using RNAseq.Methods: Total RNA from the NAc and CPu were isolated from adult male C57BL/6J mice within 1 h after the last session of oxycodone in a 14-day self-administration paradigm (4h/day, 0.25 mg/kg/infusion, FR1 or from yoked saline controls. Gene expressions were examined using RNA sequencing (RNA-Seq technology. RNA-Seq libraries were prepared using Illumina's TruSeq® Stranded Total RNA LT kit. The reads were aligned to the mouse reference genome (version mm10 using STAR. DESeq2 was applied to the counts of protein coding genes to estimate the fold change between the treatment groups. False Discovery Rate (FDR q < 0.1 were used to select genes that have a significant expression change. For selection of a subset of genes related to axon guidance pathway, REACTOME was used.Results: Among 38 known genes of the integrin, semaphorin, and ephrin gene families, RNA-seq data revealed up-regulation of six genes in the NAc: heterodimer receptor, integrins Itgal, Itgb2, and Itgam, and its ligand semaphorin Sema7a, two semaphorin receptors, plexins Plxnd1 and Plxdc1. There was

  11. Expression of adhesion and activation molecules on lymphocytes during open-heart surgery with cardiopulmonary bypass

    DEFF Research Database (Denmark)

    Toft, P; Tønnesen, Else Kirstine; Zülow, I

    1997-01-01

    Open-heart surgery with cardiopulmonary bypass (CPB) and abdominal surgery are associated with lymphocytopenia. We measured a panel of adhesion and activation molecules on lymphocytes to clarify possible association of CPB with increased expression of these molecules. Eight patients undergoing open...... open-heart and abdominal surgery. The proportion of CD11a/CD18-positive lymphocytes rose from 67.6 +/- 8% to 86.4 +/- 3% after aortic declamping (p ... was associated with increased expression of the adhesion molecule CD11a/CD18 on lymphocytes, while the expression of activation molecules on lymphocytes was unchanged....

  12. Phenotypic complexity of T regulatory subsets in patients with B-chronic lymphocytic leukemia.

    Science.gov (United States)

    Biancotto, Angélique; Dagur, Pradeep K; Fuchs, John C; Wiestner, Adrian; Bagwell, C Bruce; McCoy, J Philip

    2012-02-01

    Increased numbers of T regulatory (T(reg)) cells are found in B-chronic lymphocytic leukemia, but the nature and function of these T(regs) remains unclear. Detailed characterization of the T(regs) in chronic lymphocytic leukemia has not been performed and the degree of heterogeneity of among these cells has not been studied to date. Using 15-color flow cytometry we show that T(reg) cells, defined using CD4, CD25, and forkhead box P3 (FOXP3), can be divided into multiple complex subsets based on markers used for naïve, memory, and effector delineation as well as markers of T(reg) activation. Furthermore FOXP3(+) cells can be identified among CD4(+)CD25(-) as well as CD8(+)CD4(-) populations in increased proportions in patients with chronic lymphocytic leukemia compared with healthy donors. Significantly different frequencies of naïve and effector T(regs) populations are found in healthy donor controls compared with donors with chronic lymphocytic leukemia. A population of CCR7(+)CD39(+) T(regs) was significantly associated with chronic lymphocytic leukemia. This population demonstrated slightly reduced suppressive activity compared with total T(regs) or T(regs) of healthy donors. These data suggest that FOXP3-expressing cells, particularly in patients with chronic lymphocytic leukemia are much more complex for T(reg) sub-populations and transitions than previously reported. These findings demonstrate the complexity of regulation of T-cell responses in chronic lymphocytic leukemia and illustrate the use of high-dimensional analysis of cellular phenotypes in facilitating understanding of the intricacies of cellular immune responses and their dysregulation in cancer.

  13. 9-cis-retinoic Acid and troglitazone impacts cellular adhesion, proliferation, and integrin expression in K562 cells.

    Science.gov (United States)

    Hanson, Amanda M; Gambill, Jessica; Phomakay, Venusa; Staten, C Tyler; Kelley, Melissa D

    2014-01-01

    Retinoids are established pleiotropic regulators of both adaptive and innate immune responses. Recently, troglitazone, a PPAR gamma agonist, has been demonstrated to have anti-inflammatory effects. Separately, retinoids and troglitazone are implicated in immune related processes; however, their combinatory role in cellular adhesion and proliferation has not been well established. In this study, the effect of 9-cis-retinoic acid (9-cis-RA) and troglitazone on K562 cellular adhesion and proliferation was investigated. Troglitazone exposure decreased K562 cellular adhesion to RGD containing extracellular matrix proteins fibronectin, FN-120, and vitronectin in a concentration and time-dependent manner. In the presence of troglitazone, 9-cis-retinoic acid restores cellular adhesion to levels comparable to vehicle treatment alone on fibronectin, FN-120, and vitronectin substrates within 72 hours. Due to the prominent role of integrins in attachment to extracellular matrix proteins, we evaluated the level of integrin α5 subunit expression. Troglitazone treatment results in decrease in α5 subunit expression on the cell surface. In the presence of both agonists, cell surface α5 subunit expression was restored to levels comparable to vehicle treatment alone. Additionally, troglitazone and 9-cis-RA mediated cell adhesion was decreased in the presence of a function blocking integrin alpha 5 inhibitor. Further, through retinoid metabolic profiling and HPLC analysis, our study demonstrates that troglitazone augments retinoid availability in K562 cells. Finally, we demonstrate that troglitazone and 9-cis-retinoic acid synergistically dampen cellular proliferation in K562 cells. Our study is the first to report that the combination of troglitazone and 9-cis-retinoic acid restores cellular adhesion, alters retinoid availability, impacts integrin expression, and dampens cellular proliferation in K562 cells.

  14. Alteration of Pituitary Tumor Transforming Gene-1 Regulates Trophoblast Invasion via the Integrin/Rho-Family Signaling Pathway.

    Directory of Open Access Journals (Sweden)

    Seung Mook Lim

    Full Text Available Trophoblast invasion ability is an important factor in early implantation and placental development. Recently, pituitary tumor transforming gene 1 (PTTG1 was shown to be involved in invasion and proliferation of cancer. However, the role of PTTG1 in trophoblast invasion remains unknown. Thus, in this study we analyzed PTTG1 expression in trophoblasts and its effect on trophoblast invasion activity and determined the mechanism through which PTTG1 regulates trophoblast invasion. Trophoblast proliferation and invasion abilities, regardless of PTTG1 expression, were analyzed by quantitative real-time polymerase chain reaction, fluorescence-activated cell sorting analysis, invasion assay, western blot, and zymography after treatment with small interfering RNA against PTTG1 (siPTTG1. Additionally, integrin/Rho-family signaling in trophoblasts by PTTG1 alteration was analyzed. Furthermore, the effect of PTTG1 on trophoblast invasion was evaluated by microRNA (miRNA mimic and inhibitor treatment. Trophoblast invasion was significantly reduced through decreased matrix metalloproteinase (MMP-2 and MMP-9 expression when PTTG1 expression was inhibited by siPTTG1 (p < 0.05. Furthermore, knockdown of PTTG1 increased expression of integrin alpha 4 (ITGA4, ITGA5, and integrin beta 1 (ITGB1; otherwise, RhoA expression was significantly decreased (p < 0.05. Treatment of miRNA-186-5p mimic and inhibitor controlled trophoblast invasion ability by altering PTTG1 and MMP expression. PTTG1 can control trophoblast invasion ability via regulation of MMP expression through integrin/Rho-family signaling. In addition, PTTG1 expression and its function were regulated by miRNA-186-5p. These results help in understanding the mechanism through which PTTG1 regulates trophoblast invasion and thereby implantation and placental development.

  15. Assessing activation of hepatic stellate cells by 99mTc-3PRGD2 scintigraphy targeting integrin αvβ3: a feasibility study

    International Nuclear Information System (INIS)

    Zhang, Xin; Xin, Jun; Shi, Yu; Xu, Weina; Yu, Shupeng; Yang, Zhiguang; Liu, Changping; Cao, Li; Guo, Qiyong

    2015-01-01

    Objective: Hepatic stellate cell (HSC) activation, which is accompanied by increased expression of integrin αvβ3, is an important factor in liver fibrogenesis. Molecular imaging targeting the integrin αvβ3 could provide a non-invasive method for evaluating the expression and the function of the integrin αvβ3 on the activated HSCs (aHSCs) in the injured liver, and then provide important prognostic information. 99m Tc-3PRGD2 is such a radiotracer specific for integrin αvβ3. In this study, we aimed to compare the differences in liver uptake and retention of the 99m Tc-3PRGD2 between normal liver and injured liver to evaluate the feasibility of 99m Tc-3PRGD2 scintigraphy for this purpose. Methods: We used planar scintigraphy to assess changes in integrin αvβ3 binding of intravenously-administered 99m Tc-3PRGD2 in the livers of rats with thioacetamide (TAA)-induced liver fibrosis compared with the controls. We co-injected cold c(RGDyK) with 99m Tc-3PRGD2 to assess the specific binding of the radiotracer. We performed Sirius red staining to assess liver fibrosis, immunofluorescent colocalization to identify the location of integrin αvβ3 expressed in the fibrotic liver, and we measured protein and messenger RNA expression of integrin αvβ3 and alpha smooth muscle actin (α-SMA) in the control and fibrotic livers. Results: The fibrotic livers showed enhanced 99m Tc-3PRGD2 uptake and retention. The radiotracer was demonstrated to bind specifically with the integrin αvβ3 mainly expressed on the aHSCs. The liver-to-heart ratio at 30 min post-injection was higher in the fibrotic livers than in the control livers (TAA, 1.98 ± 0.08 vs. control, 1.50 ± 0.12, p < 0.01). The liver t 1/2 was longer than in the controls (TAA, 27.07 ± 10.69 min vs. control, 12.67 ± 4.10 min, p < 0.01). The difference of heart t 1/2 between the two groups was not statistically significant (TAA, 3.13 ± 0.63 min vs. control, 3.41 ± 0.77 min, p = 0.94). Conclusions: 99m Tc-3PRGD2

  16. Integrin-linked kinase: a Scaffold protein unique among its ilk.

    Science.gov (United States)

    Dagnino, Lina

    2011-06-01

    Integrin-linked kinase (ILK) is a scaffolding protein with central roles in tissue development and homeostasis. Much debate has focused on whether ILK is a bona fide or a pseudo- kinase. This aspect of ILK function has been complicated by the large volumes of conflicting observations obtained from a wide variety of experimental approaches, from in vitro models, to analyses in invertebrates and in mammals. Key findings in support or against the notion that ILK is catalytically active are summarized. The importance of ILK as an adaptor protein is well established, and defining its role as a signaling hub will be the next key step to understand its distinct biological roles across tissues and species.

  17. Transmembrane collagen XVII modulates integrin dependent keratinocyte migration via PI3K/Rac1 signaling.

    Directory of Open Access Journals (Sweden)

    Stefanie Löffek

    Full Text Available The hemidesmosomal transmembrane component collagen XVII (ColXVII plays an important role in the anchorage of the epidermis to the underlying basement membrane. However, this adhesion protein seems to be also involved in the regulation of keratinocyte migration, since its expression in these cells is strongly elevated during reepithelialization of acute wounds and in the invasive front of squamous cell carcinoma, while its absence in ColXVII-deficient keratinocytes leads to altered cell motility. Using a genetic model of murine Col17a1⁻/⁻ keratinocytes we elucidated ColXVII mediated signaling pathways in cell adhesion and migration. Col17a1⁻/⁻ keratinocytes exhibited increased spreading on laminin 332 and accelerated, but less directed cell motility. These effects were accompanied by increased expression of the integrin subunits β4 and β1. The migratory phenotype, as evidenced by formation of multiple unstable lamellipodia, was associated with enhanced phosphoinositide 3-kinase (PI3K activity. Dissection of the signaling pathway uncovered enhanced phosphorylation of the β4 integrin subunit and the focal adhesion kinase (FAK as activators of PI3K. This resulted in elevated Rac1 activity as a downstream consequence. These results provide mechanistic evidence that ColXVII coordinates keratinocyte adhesion and directed motility by interfering integrin dependent PI3K activation and by stabilizing lamellipodia at the leading edge of reepithelializing wounds and in invasive squamous cell carcinoma.

  18. CD4dullCD8bright double-positive T-lymphocytes have a phenotype of granzyme Bpos CD8pos memory T-lymphocytes

    NARCIS (Netherlands)

    Rentenaar, R. J.; Wever, P. C.; van Diepen, F. N.; Schellekens, P. T.; Wertheim, P. M.; ten Berge, I. J.

    1999-01-01

    BACKGROUND: T-lymphocytes that co-express CD4 and CD8 antigens may be found in small percentages in the peripheral blood of healthy individuals, and have a CD4brightCD8dull phenotype. CD4dullCD8bright T-lymphocytes have been found only in temporal association with some viral infections. METHODS:

  19. The cysteine-rich domain of human ADAM 12 supports cell adhesion through syndecans and triggers signaling events that lead to beta1 integrin-dependent cell spreading

    DEFF Research Database (Denmark)

    Iba, K; Albrechtsen, R; Gilpin, B

    2000-01-01

    The ADAMs (a disintegrin and metalloprotease) family of proteins is involved in a variety of cellular interactions, including cell adhesion and ecto- domain shedding. Here we show that ADAM 12 binds to cell surface syndecans. Three forms of recombinant ADAM 12 were used in these experiments......-dependent manner attach to ADAM 12 via members of the syndecan family. After binding to syndecans, mesenchymal cells spread and form focal adhesions and actin stress fibers. Integrin beta1 was responsible for cell spreading because function-blocking monoclonal antibodies completely inhibited cell spreading......, and chondroblasts lacking beta1 integrin attached but did not spread. These data suggest that mesenchymal cells use syndecans as the initial receptor for the ADAM 12 cysteine-rich domain-mediated cell adhesion, and then the beta1 integrin to induce cell spreading. Interestingly, carcinoma cells attached but did...

  20. Mechanism of chlorphentermine-induced lymphocyte toxicity: initial investigations

    International Nuclear Information System (INIS)

    Sauers, L.J.; Wierda, D.; Reasor, M.J.

    1986-01-01

    Chlorphentermine (CP) inhibits the blastogenic response of mouse splenic and human peripheral blood lymphocytes to the T-cell mitogens, phytohemagglutinin (PHA) and concanavalin A (Con A). The purpose of these studies was to examine in vitro the mechanism mediating this immunosuppression. If mouse or human lymphocytes are pretreated with CP for 30 minutes, then stimulated with PHA, their blastogenic response is inhibited 80% and 45%, respectively. However, if CP is not added until 10 minutes or later following PHA stimulation, the inhibitory effect of the drug is essentially eliminated. The authors also determined that CP can potentiate Con A-induced agglutination of human lymphocytes. Enhanced agglutination can result from changes in the integrity of membrane phospholipids. Because changes in membrane phospholipid biochemistry characteristically occur within 10 minutes after mitogen-induced lymphocyte activation, the authors examined whether CP altered the incorporation of choline into cellular phospholipids. They found that CP decreases overall incorporation of 14 C-choline into cellular phospholipids of mouse lymphocytes by 45% during the first 4 hours of activation. These data suggest that the immunotoxicity associated with CP may be mediated by drug-induced changes at the membrane level that appear to occur early during lymphocyte activation

  1. Cellular and substrate adhesion molecules (integrins) and their ligands in cerebral amyloid plaques in Alzheimer's disease

    NARCIS (Netherlands)

    Eikelenboom, P.; Zhan, S. S.; Kamphorst, W.; van der Valk, P.; Rozemuller, J. M.

    1994-01-01

    Integrins belonging to different subfamilies can be identified immunohistochemically in cerebral amyloid plaques. Monoclonal antibodies against the VLA family beta 1-integrins show staining of the corona of classical amyloid plaques for beta 1, alpha 3 and alpha 6. Immunostaining reveal also the

  2. The behavior of pig lymphocyte populations in vivo

    International Nuclear Information System (INIS)

    Binns, R.M.; Licence, S.T.; Pabst, R.

    1986-01-01

    Lymphocyte migration provides the means of rapidly recognizing and responding to antigen and widely disseminating the resulting immune response. The porcine lymphoid system differs from that of man in structural inversion of lymph nodes and route of lymphocyte recirculation and the existence of two Peyer's patch types, one of which differs from the conventional pattern in structure, cell content and lack of lymphocyte traffic and in its regression in old age. Recirculating T and B lymphocytes enter and leave spleen and lymph nodes by the blood but Null cells do not; lymphocytes also migrate through nonlymphoid tissues. The lung is one such important site, with a small migration in and out of alveolar space and a large traffic associated with the blood vessel wall, predominantly involving T cells. Blood lymphocytes hardly traffic into the peritoneal cavity, yet major traffic of particulate material or cells is possible in this important site of abdominal defense, so often used for immunization, and follows a distinct, well defined route. Cells migrate out of subcutaneous tissue via the draining node. Lymphocytes are produced and emigrate into blood from labelled thymus. They differ in size and surface phenotype from both thymocytes and peripheral T cells. Lymphocytes also migrate from blood into most tissues. In most nonlymphoid tissues, entry relates to blood flow but in many lymphoid tissues it is an active process which differs in tempo and extent, eg, between different nodes and between the two Peyer's patch types

  3. Pregnancy-specific glycoproteins bind integrin αIIbβ3 and inhibit the platelet-fibrinogen interaction.

    Science.gov (United States)

    Shanley, Daniel K; Kiely, Patrick A; Golla, Kalyan; Allen, Seamus; Martin, Kenneth; O'Riordan, Ronan T; Ball, Melanie; Aplin, John D; Singer, Bernhard B; Caplice, Noel; Moran, Niamh; Moore, Tom

    2013-01-01

    Pregnancy-specific glycoproteins (PSGs) are immunoglobulin superfamily members encoded by multigene families in rodents and primates. In human pregnancy, PSGs are secreted by the syncytiotrophoblast, a fetal tissue, and reach a concentration of up to 400 ug/ml in the maternal bloodstream at term. Human and mouse PSGs induce release of anti-inflammatory cytokines such as IL-10 and TGFβ1 from monocytes, macrophages, and other cell types, suggesting an immunoregulatory function. RGD tri-peptide motifs in the majority of human PSGs suggest that they may function like snake venom disintegrins, which bind integrins and inhibit interactions with ligands. We noted that human PSG1 has a KGD, rather than an RGD motif. The presence of a KGD in barbourin, a platelet integrin αIIbβ3 antagonist found in snake venom, suggested that PSG1 may be a selective αIIbβ3 ligand. Here we show that human PSG1 binds αIIbβ3 and inhibits the platelet - fibrinogen interaction. Unexpectedly, however, the KGD is not critical as multiple PSG1 domains independently bind and inhibit αIIbβ3 function. Human PSG9 and mouse Psg23 are also inhibitory suggesting conservation of this function across primate and rodent PSG families. Our results suggest that in species with haemochorial placentation, in which maternal blood is in direct contact with fetal trophoblast, the high expression level of PSGs reflects a requirement to antagonise abundant (3 mg/ml) fibrinogen in the maternal circulation, which may be necessary to prevent platelet aggregation and thrombosis in the prothrombotic maternal environment of pregnancy.

  4. Chronic lymphocytic leukemia-associated chromosomal abnormalities and miRNA deregulation

    Directory of Open Access Journals (Sweden)

    Kiefer Y

    2012-03-01

    Full Text Available Yvonne Kiefer1, Christoph Schulte2, Markus Tiemann2, Joern Bullerdiek11Center for Human Genetics, University of Bremen, Bremen, Germany; 2Hematopathology Hamburg, Hamburg, GermanyAbstract: Chronic lymphocytic leukemia is the most common leukemia in adults. By cytogenetic investigations major subgroups of the disease can be identified that reflect different routes of tumor development. Of these chromosomal deviations, trisomy 12 and deletions of parts of either the long arm of chromosome 13, the long arm of chromosome 11, or the short arm of chromosome 17 are most commonly detected. In some of these aberrations the molecular target has been identified as eg, ataxia telangiectasia mutated (ATM in case of deletions of chromosomal region 11q22~23 and the genes encoding microRNAs miR-15a/16-1 as likely targets of deletions of chromosomal band 13q14.3. Of note, these aberrations do not characterize independent subgroups but often coexist within the metaphases of one tumor. Generally, complex aberrations are associated with a worse prognosis than simple karyotypic alterations. Due to smaller sizes of the missing segment the detection of recurrent deletions is not always possible by means of classical cytogenetics but requires more advanced techniques as in particular fluorescence in situ hybridization (FISH. Nevertheless, at this time it is not recommended to replace classical cytogenetics by FISH because this would miss additional information given by complex or secondary karyotypic alterations. However, the results of cytogenetic analyses allow the stratification of prognostic and predictive groups of the disease. Of these, the group characterized by deletions involving TP53 is clinically most relevant. In the future refined methods as eg, array-based comparative genomic hybridization will supplement the existing techniques to characterize CLL. Keywords: chronic lymphocytic leukemia, chromosomal abnormality, miRNA deregulation

  5. Dwarfism in Mice Lacking Collagen-binding Integrins α2β1 and α11β1 Is Caused by Severely Diminished IGF-1 Levels*

    Science.gov (United States)

    Blumbach, Katrin; Niehoff, Anja; Belgardt, Bengt F.; Ehlen, Harald W. A.; Schmitz, Markus; Hallinger, Ralf; Schulz, Jan-Niklas; Brüning, Jens C.; Krieg, Thomas; Schubert, Markus; Gullberg, Donald; Eckes, Beate

    2012-01-01

    Mice with a combined deficiency in the α2β1 and α11β1 integrins lack the major receptors for collagen I. These mutants are born with inconspicuous differences in size but develop dwarfism within the first 4 weeks of life. Dwarfism correlates with shorter, less mineralized and functionally weaker bones that do not result from growth plate abnormalities or osteoblast dysfunction. Besides skeletal dwarfism, internal organs are correspondingly smaller, indicating proportional dwarfism and suggesting a systemic cause for the overall size reduction. In accordance with a critical role of insulin-like growth factor (IGF)-1 in growth control and bone mineralization, circulating IGF-1 levels in the sera of mice lacking either α2β1 or α11β1 or both integrins were sharply reduced by 39%, 64%, or 81% of normal levels, respectively. Low hepatic IGF-1 production resulted from diminished growth hormone-releasing hormone expression in the hypothalamus and, subsequently, reduced growth hormone expression in the pituitary glands of these mice. These findings point out a novel role of collagen-binding integrin receptors in the control of growth hormone/IGF-1-dependent biological activities. Thus, coupling hormone secretion to extracellular matrix signaling via integrins represents a novel concept in the control of endocrine homeostasis. PMID:22210772

  6. Dwarfism in mice lacking collagen-binding integrins α2β1 and α11β1 is caused by severely diminished IGF-1 levels.

    Science.gov (United States)

    Blumbach, Katrin; Niehoff, Anja; Belgardt, Bengt F; Ehlen, Harald W A; Schmitz, Markus; Hallinger, Ralf; Schulz, Jan-Niklas; Brüning, Jens C; Krieg, Thomas; Schubert, Markus; Gullberg, Donald; Eckes, Beate

    2012-02-24

    Mice with a combined deficiency in the α2β1 and α11β1 integrins lack the major receptors for collagen I. These mutants are born with inconspicuous differences in size but develop dwarfism within the first 4 weeks of life. Dwarfism correlates with shorter, less mineralized and functionally weaker bones that do not result from growth plate abnormalities or osteoblast dysfunction. Besides skeletal dwarfism, internal organs are correspondingly smaller, indicating proportional dwarfism and suggesting a systemic cause for the overall size reduction. In accordance with a critical role of insulin-like growth factor (IGF)-1 in growth control and bone mineralization, circulating IGF-1 levels in the sera of mice lacking either α2β1 or α11β1 or both integrins were sharply reduced by 39%, 64%, or 81% of normal levels, respectively. Low hepatic IGF-1 production resulted from diminished growth hormone-releasing hormone expression in the hypothalamus and, subsequently, reduced growth hormone expression in the pituitary glands of these mice. These findings point out a novel role of collagen-binding integrin receptors in the control of growth hormone/IGF-1-dependent biological activities. Thus, coupling hormone secretion to extracellular matrix signaling via integrins represents a novel concept in the control of endocrine homeostasis.

  7. Saccharomyces boulardii improves intestinal epithelial cell restitution by inhibiting αvβ5 integrin activation state.

    Directory of Open Access Journals (Sweden)

    Alexandra Canonici

    Full Text Available Intestinal epithelial cell damage is frequently seen in the mucosal lesions of infectious or inflammatory bowel diseases such as ulcerative colitis or Crohn's disease. Complete remission of these diseases requires both the disappearance of inflammation and the repair of damaged epithelium. Saccharomyces boulardii (Sb, Biocodex is a non-pathogenic yeast widely used as a preventive and therapeutic probiotic for the prevention and treatment of diarrhea and other gastrointestinal disorders. We recently showed that it enhances the repair of intestinal epithelium through activation of α2β1 integrin collagen receptors. In the present study, we demonstrated that α2β1 integrin is not the sole cell-extracellular matrix receptor involved during Sb-mediated intestinal restitution. Indeed, by using cell adhesion assays, we showed that Sb supernatant contains heat sensitive molecule(s, with a molecular weight higher than 9 kDa, which decreased αvβ5 integrin-mediated adhesion to vitronectin by competing with the integrin. Moreover, Sb-mediated changes in cell adhesion to vitronectin resulted in a reduction of the αvβ5signaling pathway. We used a monolayer wounding assay that mimics in vivo cell restitution to demonstrate that down-modulation of the αvβ5 integrin-vitronectin interaction is related to Sb-induced cell migration. We therefore postulated that Sb supernatant contains motogenic factors that enhance cell restitution through multiple pathways, including the dynamic fine regulation of αvβ5 integrin binding activity. This could be of major importance in diseases characterized by severe mucosal injury, such as inflammatory and infectious bowel diseases.

  8. Synthesis and evaluation of a radioiodinated peptide probe targeting αvβ6 integrin for the detection of pancreatic ductal adenocarcinoma

    International Nuclear Information System (INIS)

    Ueda, Masashi; Fukushima, Takahiro; Ogawa, Kei; Kimura, Hiroyuki; Ono, Masahiro; Yamaguchi, Takashi; Ikehara, Yuzuru; Saji, Hideo

    2014-01-01

    Highlights: • We developed a radioiodinated peptide probe targeting αvβ6 integrin ( 123 I-IFMDV2). • 123 I-IFMDV2 had a high affinity and selectivity for αvβ6 integrin. • 123 I-IFMDV2 showed a specific binding to αvβ6 integrin in vivo. • 123 I-IFMDV2 enabled clear visualization of the αvβ6-integrin-positive tumor. - Abstract: Introduction: Pancreatic ductal adenocarcinoma (PDAC) remains a major cause of cancer-related death. Since significant upregulation of αvβ6 integrin has been reported in PDAC, this integrin is a promising target for PDAC detection. In this study, we aimed to develop a radioiodinated probe for the imaging of αvβ6 integrin-positive PDAC with single-photon emission computed tomography (SPECT). Methods: Four peptide probes were synthesized and screened by competitive and saturation binding assays using 2 PDAC cell lines (AsPC-1, αvβ6 integrin-positive; MIA PaCa-2, αvβ6 integrin-negative). The probe showing the best affinity was used to study the biodistribution assay, an in vivo blocking study, and SPECT imaging using tumor bearing mice. Autoradiography and immunohistochemical analysis were also performed. Results: Among the 4 probes examined in this study, 125 I-IFMDV2 showed the highest affinity for αvβ6 integrin expressed in AsPC-1 cells and no affinity for MIA PaCa-2 cells. The accumulation of 125 I-IFMDV2 in the AsPC-1 xenograft was 3–5 times greater than that in the MIA PaCa-2 xenograft, consistent with the expression of αvβ6 integrin in each xenograft, and confirmed by immunohistochemistry. Pretreatment with excess amounts of A20FMDV2 significantly blocked the accumulation of 125 I-IFMDV2 in the AsPC-1 xenograft, but not in the MIA PaCa-2 xenograft. Furthermore, 123 I-IFMDV2 enabled clear visualization of the AsPC-1 xenograft. Conclusion: 123 I-IFMDV2 is a potential SPECT probe for the imaging of αvβ6 integrin in PDAC

  9. Foot-and-Mouth Disease Virus Receptors: Comparison of Bovine αV Integrin Utilization by Type A and O Viruses

    Science.gov (United States)

    Duque, Hernando; Baxt, Barry

    2003-01-01

    Three members of the αV integrin family of cellular receptors, αVβ1, αVβ3, and αVβ6, have been identified as receptors for foot-and-mouth disease virus (FMDV) in vitro. The virus interacts with these receptors via a highly conserved arginine-glycine-aspartic acid (RGD) amino acid sequence motif located within the βG-βH (G-H) loop of VP1. Other αV integrins, as well as several other integrins, recognize and bind to RGD motifs on their natural ligands and also may be candidate receptors for FMDV. To analyze the roles of the αV integrins from a susceptible species as viral receptors, we molecularly cloned the bovine β1, β5, and β6 integrin subunits. Using these subunits, along with previously cloned bovine αV and β3 subunits, in a transient expression assay system, we compared the efficiencies of infection mediated by αVβ1, αVβ3, αVβ5, and αVβ6 among three strains of FMDV serotype A and two strains of serotype O. While all the viruses could infect cells expressing these integrins, they exhibited different efficiencies of integrin utilization. All the type A viruses used αVβ3 and αVβ6 with relatively high efficiency, while only one virus utilized αVβ1 with moderate efficiency. In contrast, both type O viruses utilized αVβ6 and αVβ1 with higher efficiency than αVβ3. Only low levels of viral replication were detected in αVβ5-expressing cells infected with either serotype. Experiments in which the ligand-binding domains among the β subunits were exchanged indicated that this region of the integrin subunit appears to contribute to the differences in integrin utilizations among strains. In contrast, the G-H loops of the different viruses do not appear to be involved in this phenomenon. Thus, the ability of the virus to utilize multiple integrins in vitro may be a reflection of the use of multiple receptors during the course of infection within the susceptible host. PMID:12551988

  10. Loss of the α2β1 integrin alters human papilloma virus-induced squamous carcinoma progression in vivo and in vitro.

    Directory of Open Access Journals (Sweden)

    Thuy Tran

    Full Text Available Expression of the α2β1 integrin, a receptor for collagens and laminin, is altered during tumor progression. Recent studies have linked polymorphisms in the α2 integrin gene with oral, squamous cell carcinoma (SCC. To determine the α2β1 integrin's role in SCC progression, we crossed α2-null mice with K14-HPV16 transgenic animals. Pathological progression to invasive carcinoma was evaluated in HPV-positive, α2-null (HPV/KO and HPV-positive, wild-type (HPV/WT animals. α2β1 integrin expression stimulated progression from hyperplasia and papillomatosis to dysplasia with concomitant dermal mast cell infiltration. Moreover, lymph node metastasis was decreased by 31.3% in HPV/KO, compared to HPV/WT, animals. To evaluate the integrin-specific impact on the malignant epithelium versus the microenvironment, we developed primary tumor cell lines. Although transition from dysplasia to carcinoma was unaltered during spontaneous tumor development, isolated primary HPV/KO SCC cell lines demonstrated decreased migration and invasion, compared to HPV/WT cells. When HPV/WT and HPV/KO SCC cells were orthotopically injected into WT or KO hosts, tumor α2β1 integrin expression resulted in decreased tumor latency, regardless of host integrin status. HPV/WT SCC lines failed to demonstrate a proliferative advantage in vitro, however, the HPV/WT tumors demonstrated increased growth compared to HPV/KO SCC lines in vivo. Although contributions of the integrin to the microenvironment cannot be excluded, our studies indicate that α2β1 integrin expression by HPV-transformed keratinocytes modulates SCC growth and progression.

  11. Exosomes released by chronic lymphocytic leukemia cells induce the transition of stromal cells into cancer-associated fibroblasts

    Science.gov (United States)

    Paggetti, Jerome; Haderk, Franziska; Seiffert, Martina; Janji, Bassam; Distler, Ute; Ammerlaan, Wim; Kim, Yeoun Jin; Adam, Julien; Lichter, Peter; Solary, Eric; Berchem, Guy

    2015-01-01

    Exosomes derived from solid tumor cells are involved in immune suppression, angiogenesis, and metastasis, but the role of leukemia-derived exosomes has been less investigated. The pathogenesis of chronic lymphocytic leukemia (CLL) is stringently associated with a tumor-supportive microenvironment and a dysfunctional immune system. Here, we explore the role of CLL-derived exosomes in the cellular and molecular mechanisms by which malignant cells create this favorable surrounding. We show that CLL-derived exosomes are actively incorporated by endothelial and mesenchymal stem cells ex vivo and in vivo and that the transfer of exosomal protein and microRNA induces an inflammatory phenotype in the target cells, which resembles the phenotype of cancer-associated fibroblasts (CAFs). As a result, stromal cells show enhanced proliferation, migration, and secretion of inflammatory cytokines, contributing to a tumor-supportive microenvironment. Exosome uptake by endothelial cells increased angiogenesis ex vivo and in vivo, and coinjection of CLL-derived exosomes and CLL cells promoted tumor growth in immunodeficient mice. Finally, we detected α-smooth actin–positive stromal cells in lymph nodes of CLL patients. These findings demonstrate that CLL-derived exosomes actively promote disease progression by modulating several functions of surrounding stromal cells that acquire features of cancer-associated fibroblasts. PMID:26100252

  12. Optimization of Formaldehyde Cross-Linking for Protein Interaction Analysis of Non-Tagged Integrin β1

    Directory of Open Access Journals (Sweden)

    Cordula Klockenbusch

    2010-01-01

    Full Text Available Formaldehyde cross-linking of protein complexes combined with immunoprecipitation and mass spectrometry analysis is a promising technique for analysing protein-protein interactions, including those of transient nature. Here we used integrin β1 as a model to describe the application of formaldehyde cross-linking in detail, particularly focusing on the optimal parameters for cross-linking, the detection of formaldehyde cross-linked complexes, the utility of antibodies, and the identification of binding partners. Integrin β1 was found in a high molecular weight complex after formaldehyde cross-linking. Eight different anti-integrin β1 antibodies were used for pull-down experiments and no loss in precipitation efficiency after cross-linking was observed. However, two of the antibodies could not precipitate the complex, probably due to hidden epitopes. Formaldehyde cross-linked complexes, precipitated from Jurkat cells or human platelets and analyzed by mass spectrometry, were found to be composed of integrin β1, α4 and α6 or β1, α6, α2, and α5, respectively.

  13. Optimization of Formaldehyde Cross-Linking for Protein Interaction Analysis of Non-Tagged Integrin β1

    Science.gov (United States)

    Klockenbusch, Cordula; Kast, Juergen

    2010-01-01

    Formaldehyde cross-linking of protein complexes combined with immunoprecipitation and mass spectrometry analysis is a promising technique for analysing protein-protein interactions, including those of transient nature. Here we used integrin β1 as a model to describe the application of formaldehyde cross-linking in detail, particularly focusing on the optimal parameters for cross-linking, the detection of formaldehyde cross-linked complexes, the utility of antibodies, and the identification of binding partners. Integrin β1 was found in a high molecular weight complex after formaldehyde cross-linking. Eight different anti-integrin β1 antibodies were used for pull-down experiments and no loss in precipitation efficiency after cross-linking was observed. However, two of the antibodies could not precipitate the complex, probably due to hidden epitopes. Formaldehyde cross-linked complexes, precipitated from Jurkat cells or human platelets and analyzed by mass spectrometry, were found to be composed of integrin β1, α4 and α6 or β1, α6, α2, and α5, respectively. PMID:20634879

  14. Endotoxemia-induced lymphocyte apoptosis is augmented by a hyperinsulinemic-euglycemic clamp

    DEFF Research Database (Denmark)

    Nielsen, Jeppe Sylvest; A, Larsson; Brix-Christensen, Vibeke

    2005-01-01

    BACKGROUND: Sepsis and endotoxemia are associated with lymphocyte apoptosis. This has been regarded as harmful, contributing to further immune suppression in already immune-compromised patients. Because normalization of blood glucose improves outcome in critically ill patients, the authors...... hypothesized that one of the effects of insulin and normoglycemia would be inhibition of lymphocyte apoptosis. Therefore, in this experimental study in pigs, the authors examined the separate and combined effects of acute endotoxemia and a hyperinsulinemic-euglycemic clamp (HEC) on lymphocyte apoptosis...... sections of each sample, the apoptosis of B and T lymphocytes were analyzed using stereologic methods: The number of apoptotic B and T cells was estimated by fluorescence immunohistochemistry with anti-active caspase-3 and either anti-CD21 (B lymphocytes) or anti-CD3epsilon (T lymphocytes). The number...

  15. Integrin and GPCR Crosstalk in the Regulation of ASM Contraction Signaling in Asthma.

    Science.gov (United States)

    Teoh, Chun Ming; Tam, John Kit Chung; Tran, Thai

    2012-01-01

    Airway hyperresponsiveness (AHR) is one of the cardinal features of asthma. Contraction of airway smooth muscle (ASM) cells that line the airway wall is thought to influence aspects of AHR, resulting in excessive narrowing or occlusion of the airway. ASM contraction is primarily controlled by agonists that bind G protein-coupled receptor (GPCR), which are expressed on ASM. Integrins also play a role in regulating ASM contraction signaling. As therapies for asthma are based on symptom relief, better understanding of the crosstalk between GPCRs and integrins holds good promise for the design of more effective therapies that target the underlying cellular and molecular mechanism that governs AHR. In this paper, we will review current knowledge about integrins and GPCRs in their regulation of ASM contraction signaling and discuss the emerging concept of crosstalk between the two and the implication of this crosstalk on the development of agents that target AHR.

  16. Antigen presentation by hapten-specific B lymphocytes. II. Specificity and properties of antigen-presenting B lymphocytes, and function of immunoglobulin receptors

    International Nuclear Information System (INIS)

    Abbas, A.K.; Haber, S.; Rock, K.L.

    1985-01-01

    Studies were designed to examine the ability of hapten-binding murine B lymphocytes to present hapten-protein conjugates to protein antigen-specific, Ia-restricted T cell hybridomas. BALB/c B cells specific for TNP or FITC presented hapten-modified proteins (TNP-G1 phi, TNP-OVA, or FITC-OVA) to the relevant T cell hybridomas at concentrations below 0.1 microgram/ml. Effective presentation of the same antigens by B lymphocyte-depleted splenocytes, and of unmodified proteins by either hapten-binding B cells or Ig spleen cells, required about 10(3)-to 10(4)-fold higher concentrations of antigen. The use of two different haptens and two carrier proteins showed that this extremely efficient presentation of antigen was highly specific, with hapten specificity being a property of the B cells and carrier specificity of the responding T cells. The presentation of hapten-proteins by hapten-binding B lymphocytes was radiosensitive and was not affected by the depletion of plastic-adherent cells, suggesting that conventional APCs (macrophages or dendritic cells) are not required in this phenomenon. Antigen-pulsing and antibody-blocking experiments showed that this hapten-specific antigen presentation required initial binding of antigen to surface Ig receptors. Moreover, linked recognition of hapten and carrier determinants was required, but these recognition events could be temporally separated. Finally, an antigen-processing step was found to be necessary, and this step was disrupted by ionizing radiation. These data suggest a role for B cell surface Ig in providing a specific high-affinity receptor to allow efficient uptake or focusing of antigen for its subsequent processing and presentation to T lymphocytes

  17. A novel role for integrin-linked kinase in epithelial sheet morphogenesis.

    Science.gov (United States)

    Vespa, Alisa; D'Souza, Sudhir J A; Dagnino, Lina

    2005-09-01

    Integrin-linked kinase (ILK) is a multidomain protein involved in cell motility and cell-extracellular matrix interactions. ILK is found in integrin-containing focal adhesions in undifferentiated primary epidermal keratinocytes. Induction of keratinocyte differentiation by treatment with Ca(2+) triggers formation of cell-cell junctions, loss of focal adhesions, and ILK distribution to cell borders. We now show that Ca(2+) treatment of keratinocytes induces rapid (6 h) localization of tight junction (TJ) proteins. The kinetics of ILK movement toward the cell periphery mimics that of AJ components, suggesting that ILK plays a role in the early formation of cell-cell contacts. Whereas the N terminus in ILK mediates localization to cell borders, expression of an ILK deletion mutant incapable of localizing to the cell membrane (ILK 191-452) interferes with translocation of E-cadherin/beta-catenin to cell borders, precluding Ca(2+)-induced AJ formation. Cells expressing ILK 191-452 also fail to form TJ and sealed cell-cell borders and do not form epithelial sheets. Thus, we have uncovered a novel role for ILK in epithelial cell-cell adhesion, independent of its well-established role in integrin-mediated adhesion and migration.

  18. Effects and mechanism of integrin-β1 gene expression inhibited by shRNA in invasion of pancreatic carcinoma PANC-1 cells.

    Science.gov (United States)

    Yu, Feng; Li, Hua; Bu, Xuefeng; Zhang, Yongjun

    2012-01-01

    To investigate the effects of integrin-β1 gene expression inhibited by shRNA on invasion of pancreatic carcinoma PANC-1 cells in vitro. The eukaryotic expression plasmid of short hairpin RNA (shRNA) targeting integrin-β1 gene (integrin-β1-shRNA) was constructed and transfected into PANC-1 cells. The expressions of integrin-β1 mRNA and protein were detected by real-time quantitative polymerase chain reaction (PCR) and western blot assay, respectively. The invasive ability of PANC-1 cells was observed with a transwell cell culture chamber and the expressions of MMP-2 and MMP-9 were assayed. Compared to the untransfected group, recombinant expression plasmid integrin-β1-shRNA resulted in reduction of integrin-β1 mRNA and protein by 78.58%±7.24% and 92.88%±3.18%, respectively and the average number of invading PANC-1 cells were decreased from 52±5 to 21±4 (pPANC-1 cells in vitro significantly.

  19. A Key Role for NF-κB Transcription Factor c-Rel in T-Lymphocyte-Differentiation and Effector Functions

    Directory of Open Access Journals (Sweden)

    Alexander Visekruna

    2012-01-01

    Full Text Available The transcription factors of the Rel/NF-κB family function as key regulators of innate and adoptive immunity. Tightly and temporally controlled activation of NF-κB-signalling pathways ensures prevention of harmful immune cell dysregulation, whereas a loss of control leads to pathological conditions such as severe inflammation, autoimmune disease, and inflammation-associated oncogenesis. Five family members have been identified in mammals: RelA (p65, c-Rel, RelB, and the precursor proteins NF-κB1 (p105 and NF-κB2 (p100, that are processed into p50 and p52, respectively. While RelA-containing dimers are present in most cell types, c-Rel complexes are predominately found in cells of hematopoietic origin. In T-cell lymphocytes, certain genes essential for immune function such as Il2 and Foxp3 are directly regulated by c-Rel. Additionally, c-Rel-dependent IL-12 and IL-23 transcription by macrophages and dendritic cells is crucial for T-cell differentiation and effector functions. Accordingly, c-Rel expression in T cells and antigen-presenting cells (APCs controls a delicate balance between tolerance and immunity. This review gives a selective overview on recent progress in understanding of diverse roles of c-Rel in regulating adaptive immunity.

  20. Prognostic significance of neutrophil-to-lymphocyte ratio in biliary tract cancers: a systematic review and meta-analysis.

    Science.gov (United States)

    Tang, Haowen; Lu, Wenping; Li, Bingmin; Li, Chonghui; Xu, Yinzhe; Dong, Jiahong

    2017-05-30

    Inflammation was considered to perform crucial roles in the development and metastasis of malignancies. A heightened neutrophil-lymphocyte ratio has been described to be associated with detrimental survivals in different malignancies. Debate remains over the impact of heightened neutrophil-lymphocyte ratio on survivals in biliary tract cancer. The review evaluated the prognostic value of neutrophil-lymphocyte ratio in biliary tract cancer. MEDLINE, the Cochrane Library, EMBASE, and the Chinese SinoMed were systematically searched for relevant articles. Associations between neutrophil-lymphocyte ratio and long-term outcomes were expressed as the hazard ratios and 95% confidence intervals. The odds ratio was utilized to assess the association between neutrophil-lymphocyte ratio and clinicopathological parameters. Fourteen studies consisting of 3217 patients were analyzed: 1278 (39.73%) in the high pretreatment neutrophil-lymphocyte ratio group and 1939 (60.27%) in the low pretreatment neutrophil-lymphocyte ratio one. The results proved that heightened pretreatment neutrophil-lymphocyte ratio was significantly associated with detrimental overall survival and relapse free survival for biliary tract cancer patients. In addition, elevated neutrophil-lymphocyte ratio was positively correlated with higher carbohydrate antigen 19-9 levels, advanced TNM staging and greater lymph node involvement. This meta-analysis marked that an increased pretreatment neutrophil-lymphocyte ratio was significantly linked with detrimental long-term outcomes and clinicopathological parameters for patients with biliary tract cancer.