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Sample records for integrin protein levels

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

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    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.

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

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    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.

  4. 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.

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

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    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

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

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    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

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

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    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.

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

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    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.

  9. The group B streptococcal alpha C protein binds alpha1beta1-integrin through a novel KTD motif that promotes internalization of GBS within human epithelial cells.

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    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.

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

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    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.

  11. Levels of α7 integrin and laminin-α2 are increased following prednisone treatment in the mdx mouse and GRMD dog models of Duchenne muscular dystrophy

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    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.

  12. 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

  13. Integrin-mediated adhesion of human mesenchymal stem cells to extracellular matrix proteins adsorbed to polymer surfaces

    International Nuclear Information System (INIS)

    Dånmark, S; Mustafa, K; Finne-Wistrand, A; Albertsson, A-C; Patarroyo, M

    2012-01-01

    In vitro, degradable aliphatic polyesters are widely used as cell carriers for bone tissue engineering, despite their lack of biological cues. Their biological active surface is rather determined by an adsorbed layer of proteins from the surrounding media. Initial cell fate, including adhesion and proliferation, which are key properties for efficient cell carriers, is determined by the adsorbed layer of proteins. Herein we have investigated the ability of human bone marrow derived stem cells (hBMSC) to adhere to extracellular matrix (ECM) proteins, including fibronectin and vitronectin which are present in plasma and serum. hBMSC expressed integrins for collagens, laminins, fibronectin and vitronectin. Accordingly, hBMSC strongly adhered to these purified ECM proteins by using the corresponding integrins. Although purified fibronectin and vitronectin adsorbed to aliphatic polyesters to a lower extent than to cell culture polystyrene, these low levels were sufficient to mediate adhesion of hBMSC. It was found that plasma- and serum-coated polystyrene adsorbed significant levels of both fibronectin and vitronectin, and fibronectin was identified as the major adhesive component of plasma for hBMSC; however, aliphatic polyesters adsorbed minimal levels of fibronectin under similar conditions resulting in impaired cell adhesion. Altogether, the results suggest that the efficiency of aliphatic polyesters cell carriers could be improved by increasing their ability to adsorb fibronectin. (paper)

  14. 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...

  15. Integrin-linked kinase: a Scaffold protein unique among its ilk.

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    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.

  16. Tauroursodeoxycholate Protects Rat Hepatocytes from Bile Acid-Induced Apoptosis via β1-Integrin- and Protein Kinase A-Dependent Mechanisms

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    Annika Sommerfeld

    2015-05-01

    Full Text Available Background/Aims: Ursodeoxycholic acid, which in vivo is rapidly converted into its taurine conjugate, is frequently used for the treatment of cholestatic liver disease. Apart from its choleretic effects, tauroursodeoxycholate (TUDC can protect hepatocytes from bile acid-induced apoptosis, but the mechanisms underlying its anti-apoptotic effects are poorly understood. Methods: These mechanisms were investigated in perfused rat liver and isolated rat hepatocytes. Results: It was found that TUDC inhibited the glycochenodeoxycholate (GCDC-induced activation of the CD95 death receptor at the level of association between CD95 and the epidermal growth factor receptor. This was due to a rapid TUDC-induced β1-integrin-dependent cyclic AMP (cAMP signal with induction of the dual specificity mitogen-activated protein (MAP kinase phosphatase 1 (MKP-1, which prevented GCDC-induced phosphorylation of mitogen-activated protein kinase kinase 4 (MKK4 and c-jun-NH2-terminal kinase (JNK activation. Furthermore, TUDC induced a protein kinase A (PKA-mediated serine/threonine phosphorylation of the CD95, which was recently identified as an internalization signal for CD95. Furthermore, TUDC inhibited GCDC-induced CD95 targeting to the plasma membrane in a β1-integrin-and PKA-dependent manner. In line with this, the β1-integrin siRNA knockdown in sodium taurocholate cotransporting polypeptide (Ntcp-transfected HepG2 cells abolished the protective effect of TUDC against GCDC-induced apoptosis. Conclusion: TUDC exerts its anti-apoptotic effect via a β1-integrin-mediated formation of cAMP, which prevents CD95 activation by hydrophobic bile acids at the levels of JNK activation and CD95 serine/threonine phosphorylation.

  17. Xerogel Interfaced Nanofibers Stimulate Bone Regeneration Through the Activation of Integrin and Bone Morphogenetic Protein Pathways.

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    Lee, Yoo-Mi; Yun, Hyung-Mun; Lee, Hye-Young; Lim, Hyun-Chang; Lee, Hae-Hyoung; Kim, Hae-Won; Kim, Eun-Cheol

    2017-02-01

    A xerogel was interfaced onto biopolymer nanofibers though a core–shell electrospinning design for bone regeneration. The xerogel-interfaced biopolymer nanofibrous matrix was bioactive and highly hydrophilic, with a significant decrease in the water contact angle. The matrix showed excellent in vitro responses of primary osteoblasts in terms of adhesion, proliferation, and migration. Furthermore, the osteoblastic differentiation of cells, including alkaline phosphatase activity, mineralization, and gene expression, was significantly upregulated by the xerogel interface. In vivo animal tests in a critical-sized calvarial defect confirmed the new bone formation ability of the xerogel-surfaced nanofiber matrices. The underlying signaling mechanisms of the stimulation were implied to be integrin and bone morphogenetic protein (BMP) pathways, as demonstrated by the activation of integrin (α2β1) and downstream signaling molecules (FAK, paxillin, RhoA, MAPK, and NF-κB), as well as the BMPs and the downstream transcription factor Smad1/5/8. Taking these findings together, the xerogel-surfaced biopolymer nanofibers are proposed to be a promising scaffold candidate for bone regeneration.

  18. Optimization of Formaldehyde Cross-Linking for Protein Interaction Analysis of Non-Tagged Integrin β1

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    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.

  19. Optimization of Formaldehyde Cross-Linking for Protein Interaction Analysis of Non-Tagged Integrin β1

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    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

  20. 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.

  1. The β3-Integrin Binding Protein β3-Endonexin Is a Novel Negative Regulator of Hypoxia-Inducible Factor-1

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    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

  2. Recombinant Nonstructural 3 Protein, rNS3, of Hepatitis C Virus Along With Recombinant GP96 Induce IL-12, TNFα and α5integrin Expression in Antigen Presenting Cells

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    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

  3. Interactions of the integrin subunit beta1A with protein kinase B/Akt, p130Cas and paxillin contribute to regulation of radiation survival

    DEFF Research Database (Denmark)

    Seidler, Julia; Durzok, Rita; Brakebusch, Cord

    2005-01-01

    25beta1B cells, which express mutant beta1B-integrins, were compared in terms of radiation survival and beta1-integrin signaling. MATERIALS AND METHODS: Cells grown on fibronectin, collagen-III, laminin, vitronectin, anti-beta1-integrin-IgG (beta1-IgG) or poly-l-lysine were irradiated with 0-6Gy...... and phosphorylation were analyzed by Western blot technique. RESULTS: Adhesion of GD25beta1A cells to extracellular matrix proteins or beta1-IgG resulted in growth factor-independent radiation survival. In contrast, serum starved GD25beta1B cells showed a significant (Pradiation survival on all...... phosphorylation. Phosphorylated p130Cas and paxillin subsequently prevented activation of cell death-regulating JNK. CONCLUSIONS: The data show that beta1-integrin-mediated signaling through the cytoplasmic integrin domains is critical for efficient pro-survival regulation after irradiation. Profound knowledge...

  4. Synergy between an antiangiogenic integrin αv antagonist and an antibody–cytokine fusion protein eradicates spontaneous tumor metastases

    OpenAIRE

    Lode, Holger N.; Moehler, Thomas; Xiang, Rong; Jonczyk, Alfred; Gillies, Stephen D.; Cheresh, David A.; Reisfeld, Ralph A.

    1999-01-01

    The suppression and eradication of primary tumors and distant metastases is a major goal of alternative treatment strategies for cancer, such as inhibition of angiogenesis and targeted immunotherapy. We report here a synergy between two novel monotherapies directed against vascular and tumor compartments, respectively, a tumor vasculature-specific antiangiogenic integrin αv antagonist and tumor-specific antibody–interleukin 2 (IL-2) fusion proteins. Simultaneous an...

  5. 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.

  6. 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.

  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. Identification of inhibitors of α2β1 integrin, members of C-lectin type proteins, in Echis sochureki venom

    Energy Technology Data Exchange (ETDEWEB)

    Jakubowski, Piotr [Temple University, Department of Biology, Philadelphia, PA 19122 (United States); Calvete, Juan J. [Instituto de Biomedicina de Valencia, Consejo Superior de Investigaciones Cientificas, 46010 Valencia (Spain); Eble, Johannes A. [Excellence Cluster Cardio-Pulmonary System, Center for Molecular Medicine, Vascular Matrix Biology, Frankfurt University Hospital, Frankfurt am Main 60590 (Germany); Lazarovici, Philip [The Hebrew University of Jerusalem, School of Pharmacy, Institute for Drug Research, Jerusalem 91120 (Israel); Marcinkiewicz, Cezary, E-mail: cmarcink@temple.edu [Temple University, Department of Biology, Philadelphia, PA 19122 (United States)

    2013-05-15

    Snake venom antagonists of α2β1 integrin have been identified as members of a C-lectin type family of proteins (CLP). In the present study, we characterized three new CLPs isolated from Echis sochureki venom, which interact with this integrin. These proteins were purified using a combination of gel filtration, ion exchange chromatography and reverse phase HPLC. Sochicetin-A and sochicetin-B potently inhibited adhesion of cells expressing α2β1 integrin and binding of isolated α2β1 ectodomain to collagen I, as well as bound to recombinant GST-α2A domain in ELISA, whereas activity of sochicetin-C in these assays was approximately two orders of magnitude lower. Structurally, sochicetin-B and sochicetin-C are typical heterodimeric αβ CLPs, whereas sochicetin-A exhibits a trimer of its subunits (αβ){sub 3} in the quaternary structure. Immobilized sochicetins supported adhesion of glioma cell lines, LN18 and LBC3, whereas in a soluble form they partially inhibited adhesion of these cells to collagen I. Glioma cells spread very poorly on sochicetin-A, showing no cytoskeleton rearrangement typical for adhesion to collagen I or fibronectin. Adhesion on CLP does not involve focal adhesion elements, such as vinculin. Sochicetin-A also inhibited collagen-induced platelet aggregation, similar to other CLPs' action on the blood coagulation system. - Highlights: • Isolation of three novel snake venom CLPs inhibiting α2β1 integrin • Reporting hexameric CLP, sochicetin-A with anti-collagen receptor activity • CLPs antagonize the interaction of glioma cells with collagen matrix. • Sochicetin-A does not support glioma cell spreading.

  10. Identification of inhibitors of α2β1 integrin, members of C-lectin type proteins, in Echis sochureki venom

    International Nuclear Information System (INIS)

    Jakubowski, Piotr; Calvete, Juan J.; Eble, Johannes A.; Lazarovici, Philip; Marcinkiewicz, Cezary

    2013-01-01

    Snake venom antagonists of α2β1 integrin have been identified as members of a C-lectin type family of proteins (CLP). In the present study, we characterized three new CLPs isolated from Echis sochureki venom, which interact with this integrin. These proteins were purified using a combination of gel filtration, ion exchange chromatography and reverse phase HPLC. Sochicetin-A and sochicetin-B potently inhibited adhesion of cells expressing α2β1 integrin and binding of isolated α2β1 ectodomain to collagen I, as well as bound to recombinant GST-α2A domain in ELISA, whereas activity of sochicetin-C in these assays was approximately two orders of magnitude lower. Structurally, sochicetin-B and sochicetin-C are typical heterodimeric αβ CLPs, whereas sochicetin-A exhibits a trimer of its subunits (αβ) 3 in the quaternary structure. Immobilized sochicetins supported adhesion of glioma cell lines, LN18 and LBC3, whereas in a soluble form they partially inhibited adhesion of these cells to collagen I. Glioma cells spread very poorly on sochicetin-A, showing no cytoskeleton rearrangement typical for adhesion to collagen I or fibronectin. Adhesion on CLP does not involve focal adhesion elements, such as vinculin. Sochicetin-A also inhibited collagen-induced platelet aggregation, similar to other CLPs' action on the blood coagulation system. - Highlights: • Isolation of three novel snake venom CLPs inhibiting α2β1 integrin • Reporting hexameric CLP, sochicetin-A with anti-collagen receptor activity • CLPs antagonize the interaction of glioma cells with collagen matrix. • Sochicetin-A does not support glioma cell spreading

  11. 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.

  12. 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.

  13. Structural insight into the function of myelin basic protein as a ligand for integrin αMβ2

    DEFF Research Database (Denmark)

    Stapulionis, Romualdas; Oliveira, Cristiano; Gjelstrup, Mikkel Carstensen

    2008-01-01

    protein (MBP), a major autoantigen in MS, is a potent and specific ligand for the integrin αMβ2 (Mac-1, CD11b/CD18) expressed mainly on phagocytic cells. MBP undergoes a dramatic conformational change when liberated from the lipid-rich environment of the myelin sheath. The MS drug glatiramer acetate......Multiple sclerosis (MS) is an inflammatory disease where phagocytic cells infiltrate the nerve tissue and act as terminal agents in destruction of the myelin sheath. However, the mechanism that triggers the ability of these cells to recognize myelin remains obscure. We show that myelin basic...

  14. Integrin α(IIb)β₃ exists in an activated state in subjects with elevated plasma homocysteine levels.

    LENUS (Irish Health Repository)

    McGarrigle, Sarah A

    2011-01-01

    Elevated levels of plasma homocysteine (Hcy) are an independent risk factor for cardiovascular disease and thrombosis. The molecular basis for this phenomenon is not known but may relate to modification of cell surface thiols. The platelet specific integrin α(IIb)β₃ is a cysteine-rich cell adhesion molecule that plays a critical role in platelet aggregation and adhesion in haemostasis and thrombosis. In this study, we looked for evidence of a homocysteine-induced modification of α(IIb)β₃ using a fluorescently labeled PAC-1 antibody that recognizes the activated conformation of the integrin on the platelet surface. We show that exogenous Hcy (10-100 µM) and homocysteine thiolactone (HcyTL) (10-100 µM) increased PAC-1 binding to platelets in a concentration dependent manner in vitro. In parallel, we show subjects with clinical hyperhomocysteinemia exhibit a greater degree of activation of α(IIb)β₃ compared to age-matched controls. These findings demonstrate that circulating Hcy can modulate the activation state of the platelet integrin α(IIb)β₃, a key player in platelet aggregation and thrombosis.

  15. Recruitment of focal adhesion kinase and paxillin to β1 integrin promotes cancer cell migration via mitogen activated protein kinase activation

    International Nuclear Information System (INIS)

    Crowe, David L; Ohannessian, Arthur

    2004-01-01

    Integrin-extracellular matrix interactions activate signaling cascades such as mitogen activated protein kinases (MAPK). Integrin binding to extracellular matrix increases tyrosine phosphorylation of focal adhesion kinase (FAK). Inhibition of FAK activity by expression of its carboxyl terminus decreases cell motility, and cells from FAK deficient mice also show reduced migration. Paxillin is a focal adhesion protein which is also phosphorylated on tyrosine. FAK recruitment of paxillin to the cell membrane correlates with Shc phosphorylation and activation of MAPK. Decreased FAK expression inhibits papilloma formation in a mouse skin carcinogenesis model. We previously demonstrated that MAPK activation was required for growth factor induced in vitro migration and invasion by human squamous cell carcinoma (SCC) lines. Adapter protein recruitment to integrin subunits was examined by co-immunoprecipitation in SCC cells attached to type IV collagen or plastic. Stable clones overexpressing FAK or paxillin were created using the lipofection technique. Modified Boyden chambers were used for invasion assays. In the present study, we showed that FAK and paxillin but not Shc are recruited to the β1 integrin cytoplasmic domain following attachment of SCC cells to type IV collagen. Overexpression of either FAK or paxillin stimulated cancer cell migration on type IV collagen and invasion through reconstituted basement membrane which was dependent on MAPK activity. We concluded that recruitment of focal adhesion kinase and paxillin to β1 integrin promoted cancer cell migration via the mitogen activated protein kinase pathway

  16. Recruitment of focal adhesion kinase and paxillin to β1 integrin promotes cancer cell migration via mitogen activated protein kinase activation

    Directory of Open Access Journals (Sweden)

    Ohannessian Arthur

    2004-05-01

    Full Text Available Abstract Background Integrin-extracellular matrix interactions activate signaling cascades such as mitogen activated protein kinases (MAPK. Integrin binding to extracellular matrix increases tyrosine phosphorylation of focal adhesion kinase (FAK. Inhibition of FAK activity by expression of its carboxyl terminus decreases cell motility, and cells from FAK deficient mice also show reduced migration. Paxillin is a focal adhesion protein which is also phosphorylated on tyrosine. FAK recruitment of paxillin to the cell membrane correlates with Shc phosphorylation and activation of MAPK. Decreased FAK expression inhibits papilloma formation in a mouse skin carcinogenesis model. We previously demonstrated that MAPK activation was required for growth factor induced in vitro migration and invasion by human squamous cell carcinoma (SCC lines. Methods Adapter protein recruitment to integrin subunits was examined by co-immunoprecipitation in SCC cells attached to type IV collagen or plastic. Stable clones overexpressing FAK or paxillin were created using the lipofection technique. Modified Boyden chambers were used for invasion assays. Results In the present study, we showed that FAK and paxillin but not Shc are recruited to the β1 integrin cytoplasmic domain following attachment of SCC cells to type IV collagen. Overexpression of either FAK or paxillin stimulated cancer cell migration on type IV collagen and invasion through reconstituted basement membrane which was dependent on MAPK activity. Conclusions We concluded that recruitment of focal adhesion kinase and paxillin to β1 integrin promoted cancer cell migration via the mitogen activated protein kinase pathway.

  17. Integrin-mediated targeting of protein polymer nanoparticles carrying a cytostatic macrolide

    Science.gov (United States)

    Shi, Pu

    chapter illustrates how to tune the ELP sequence and architecture for either coassembly or sorting of distinct proteins into microdomains within a living cell. Passive tumor targeting utilizing enhanced permeability and retention (EPR) effect has limited efficiency in targeting non-leaky tumors such as MDA-MB-468 breast tumor; however, an RGD tri-peptide decorated micelle nanoparticle can effectively accumulate in tumor site via integrin-mediated active tumor targeting. Different from inefficient and cytotoxic chemical linkage reactions, an elastin-based multi-functional nanocarrier can be assembled by genetic protein fusion and micelle co-assembly technology. The novel drug carrier contains the cognate Rapamycin (Rapa) receptor -- FK506 binding protein (FKBP) as the high-avidity drug binding domain and an RGD peptide as the active tumor targeting domain. Here we show that by co-assembling FKBP and RGD contained protein polymers into mixed micelle nanoparticles, they not only competently targeted endothelial and tumor cells in cell assays, but specifically delivered the drug with a slow release half-life of 38h. It was demonstrated that the active tumor targeting formulation of Rapa more effectively suppressed tumor growth compared to the passive tumor targeting formulation and free drug in tumor regression studies of mouse MDA-MB-468 xenografts. We believe that the exciting results will provide a new tool for the development of next-generation "smart" multi-functional drug carriers. (Abstract shortened by UMI.).

  18. The recognition of adsorbed and denatured proteins of different topographies by β2 integrins and effects on leukocyte adhesion and activation

    DEFF Research Database (Denmark)

    Brevig, T.; Holst, B.; Ademovic, Z.

    2005-01-01

    Leukocyte beta(2) integrins Mac-1 and p150,95 are promiscuous cell-surface receptors that recognise and mediate cell adhesion to a variety of adsorbed and denatured proteins. We used albumin as a model protein to study whether leukocyte adhesion and activation depended on the nm-scale topography...

  19. 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.

  20. 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.

  1. 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...

  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. Simulated physiological stretch increases expression of extracellular matrix proteins in human bladder smooth muscle cells via integrin α4/αv-FAK-ERK1/2 signaling pathway.

    Science.gov (United States)

    Chen, Shulian; Peng, Chuandu; Wei, Xin; Luo, Deyi; Lin, Yifei; Yang, Tongxin; Jin, Xi; Gong, Lina; Li, Hong; Wang, Kunjie

    2017-08-01

    To investigate the effect of simulated physiological stretch on the expression of extracellular matrix (ECM) proteins and the role of integrin α4/αv, focal adhesion kinase (FAK), extracellular regulated protein kinases 1/2 (ERK1/2) in the stretch-induced ECM protein expression of human bladder smooth muscle cells (HBSMCs). HBSMCs were seeded onto silicone membrane and subjected to simulated physiological stretch at the range of 5, 10, and 15% elongation. Expression of primary ECM proteins in HBSMCs was analyzed by real-time polymerase chain reaction and Western blot. Specificity of the FAK and ERK1/2 was determined by Western blot with FAK inhibitor and ERK1/2 inhibitor (PD98059). Specificity of integrin α4 and integrin αv was determined with small interfering ribonucleic acid (siRNA) transfection. The expression of collagen I (Col1), collagen III (Col3), and fibronectin (Fn) was increased significantly under the simulated physiological stretch of 10 and 15%. Integrin α4 and αv, FAK, ERK1/2 were activated by 10% simulated physiological stretch compared with the static condition. Pretreatment of ERK1/2 inhibitor, FAK inhibitor, integrin α4 siRNA, or integrin αv siRNA reduced the stretch-induced expression of ECM proteins. And FAK inhibitor decreased the stretch-induced ERK1/2 activity and ECM protein expression. Integrin α4 siRNA or integrin αv siRNA inhibited the stretch-induced activity of FAK. Simulated physiological stretch increases the expression of ECM proteins in HBSMCs, and integrin α4/αv-FAK-ERK1/2 signaling pathway partly modulates the mechano-transducing process.

  4. 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.

  5. Alternagin-C, a disintegrin-like protein from the venom of Bothrops alternatus, modulates a2ß1 integrin-mediated cell adhesion, migration and proliferation

    Directory of Open Access Journals (Sweden)

    Selistre-de-Araujo H.S.

    2005-01-01

    Full Text Available The alpha2ß1 integrin is a major collagen receptor that plays an essential role in the adhesion of normal and tumor cells to the extracellular matrix. Alternagin-C (ALT-C, a disintegrin-like protein purified from the venom of the Brazilian snake Bothrops alternatus, competitively interacts with the alpha2ß1 integrin, thereby inhibiting collagen binding. When immobilized in plate wells, ALT-C supports the adhesion of fibroblasts as well as of human vein endothelial cells (HUVEC and does not detach cells previously bound to collagen I. ALT-C is a strong inducer of HUVEC proliferation in vitro. Gene expression analysis was done using an Affimetrix HU-95A probe array with probe sets of ~10,000 human genes. In human fibroblasts growing on collagen-coated plates, ALT-C up-regulates the expression of several growth factors including vascular endothelial growth factor, as well as some cell cycle control genes. Up-regulation of the vascular endothelial growth factor gene and other growth factors could explain the positive effect on HUVEC proliferation. ALT-C also strongly activates protein kinase B phosphorylation, a signaling event involved in endothelial cell survival and angiogenesis. In human neutrophils, ALT-C has a potent chemotactic effect modulated by the intracellular signaling cascade characteristic of integrin-activated pathways. Thus, ALT-C acts as a survival factor, promoting adhesion, migration and endothelial cell proliferation after binding to alpha2ß1 integrin on the cell surface. The biological activities of ALT-C may be helpful as a therapeutic strategy in tissue regeneration as well as in the design of new therapeutic agents targeting alpha2ß1 integrin.

  6. 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.

  7. 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.

  8. 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

  9. 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.

  10. 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.

  11. Protein Tyrosine Phosphatase-PEST and β8 Integrin Regulate Spatiotemporal Patterns of RhoGDI1 Activation in Migrating Cells

    Science.gov (United States)

    Lee, Hye Shin; Cheerathodi, Mujeeburahiman; Chaki, Sankar P.; Reyes, Steve B.; Zheng, Yanhua; Lu, Zhimin; Paidassi, Helena; DerMardirossian, Celine; Lacy-Hulbert, Adam; Rivera, Gonzalo M.

    2015-01-01

    Directional cell motility is essential for normal development and physiology, although how motile cells spatiotemporally activate signaling events remains largely unknown. Here, we have characterized an adhesion and signaling unit comprised of protein tyrosine phosphatase (PTP)-PEST and the extracellular matrix (ECM) adhesion receptor β8 integrin that plays essential roles in directional cell motility. β8 integrin and PTP-PEST form protein complexes at the leading edge of migrating cells and balance patterns of Rac1 and Cdc42 signaling by controlling the subcellular localization and phosphorylation status of Rho GDP dissociation inhibitor 1 (RhoGDI1). Translocation of Src-phosphorylated RhoGDI1 to the cell's leading edge promotes local activation of Rac1 and Cdc42, whereas dephosphorylation of RhoGDI1 by integrin-bound PTP-PEST promotes RhoGDI1 release from the membrane and sequestration of inactive Rac1/Cdc42 in the cytoplasm. Collectively, these data reveal a finely tuned regulatory mechanism for controlling signaling events at the leading edge of directionally migrating cells. PMID:25666508

  12. Amino acid sequences mediating vascular cell adhesion molecule 1 binding to integrin alpha 4: homologous DSP sequence found for JC polyoma VP1 coat protein

    Directory of Open Access Journals (Sweden)

    Michael Andrew Meyer

    2013-07-01

    Full Text Available The JC polyoma viral coat protein VP1 was analyzed for amino acid sequences homologies to the IDSP sequence which mediates binding of VLA-4 (integrin alpha 4 to vascular cell adhesion molecule 1. Although the full sequence was not found, a DSP sequence was located near the critical arginine residue linked to infectivity of the virus and binding to sialic acid containing molecules such as integrins (3. For the JC polyoma virus, a DSP sequence was found at residues 70, 71 and 72 with homology also noted for the mouse polyoma virus and SV40 virus. Three dimensional modeling of the VP1 molecule suggests that the DSP loop has an accessible site for interaction from the external side of the assembled viral capsid pentamer.

  13. A multi-domain protein for beta1 integrin-targeted DNA delivery.

    NARCIS (Netherlands)

    E. Fortunati (Elisabetta); E.M.E. Ehlert (Ehrich); N.D. van Loo; C. Wyman (Claire); J.A. Eble; F.G. Grosveld (Frank); B.J. Scholte (Bob)

    2000-01-01

    textabstractThe development of effective receptor-targeted nonviral vectors for use in vivo is complicated by a number of technical problems. One of these is the low efficiency of the conjugation procedures used to couple protein ligands to the DNA condensing carrier molecules. We have made and

  14. Prostate Cancer Progression and Serum Sibling (Small Integrin Binding N-Linked Glycoprotein) Levels

    Science.gov (United States)

    2008-10-01

    4302. Respondents should be aware that notwithstanding any other provision of law , no person shall be subject to any penalty for failing to comply...SIBLING proteins, bone sialoprotein, and osteopontin. Biochem Biophys Res Commun 2001;280:460–465. [PubMed: 11162539] 27. Tompa P, Szasz C, Buday L

  15. 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.

  16. Distribution of cytoskeletal proteins, integrins, leukocyte adhesion molecules and extracellular matrix proteins in plastic-embedded human and rat kidneys

    NARCIS (Netherlands)

    van Goor, H; Coers, W; van der Horst, MLC; Suurmeijer, AJH

    2001-01-01

    OBJECTIVE: To study the distribution of cytoskeletal proteins (actin, alpha -actinin, vinculin, beta -tubulin, keratin, vimentin, desmin), adhesion molecules for cell-matrix interations (very later antigens [VLA1-6], beta1, beta2 [CD18], vitronectin receptor [alphav beta3], CD 11b), leukocyte

  17. 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

  18. 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.

  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. 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. 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

  2. The translational blocking of α5 and α6 integrin subunits affects migration and invasion, and increases sensitivity to carboplatin of SKOV-3 ovarian cancer cell line

    Energy Technology Data Exchange (ETDEWEB)

    Villegas-Pineda, Julio César, E-mail: jcvillegas@cinvestav.mx; Toledo-Leyva, Alfredo, E-mail: toledo_leyva@hotmail.com; Osorio-Trujillo, Juan Carlos, E-mail: clostrujillo2@yahoo.com.mx; Hernández-Ramírez, Verónica Ivonne, E-mail: arturomvi@hotmail.com; Talamás-Rohana, Patricia, E-mail: ptr@cinvestav.mx

    2017-02-15

    Epithelial ovarian cancer is the most lethal gynecologic malignancy. Integrins, overexpressed in cancer, are involved in various processes that favor the development of the disease. This study focused on determining the degree of involvement of α5, α6 and β3 integrin subunits in the establishment/development of epithelial ovarian cancer (EOC), such as proliferation, migration, invasion, and response to carboplatin. The translation of the α5, α6 and β3 integrins was blocked using morpholines, generating morphant cells for these proteins, which were corroborated by immunofluorescence assays. WST-1 proliferation assay showed that silencing of α5, α6, and β3 integrins does not affect the survival of morphants. Wound healing and transwell chamber assays showed that blocking α5 and α6 integrins decrease, in lesser and greater level respectively, the migratory and the invasive capacity of SKOV-3 cells. Finally, blocking α5 and α6 integrins partially sensitized the cells response to carboplatin, while blocking integrin β3 generated resistance to this drug. Statistical analyses were performed with the GraphPad Prism 5.0 software employing one way and two-way ANOVA tests; data are shown as average±SD. Results suggest that α5 and α6 integrins could become good candidates for chemotherapy targets in EOC.

  3. Fps/Fes protein-tyrosine kinase regulates mast cell adhesion and migration downstream of Kit and beta1 integrin receptors.

    Science.gov (United States)

    Smith, Julie A; Samayawardhena, Lionel A; Craig, Andrew W B

    2010-03-01

    Activation of Kit receptor protein-tyrosine kinase (PTK) by its ligand Stem Cell Factor (SCF) is required for the development of mast cells, and for the regulation of mast cell proliferation, migration and modulation of inflammatory mediator release. Recent studies have implicated the non-receptor PTK Fps/Fes (hereafter referred to as Fes) in signaling downstream of oncogenic Kit, however, the potential role of Fes in regulating Kit signaling is not well defined. In this study, we show that SCF induces transient tyrosine phosphorylation of wild-type Fes as well as kinase-dead Fes in bone marrow-derived mast cells (BMMCs). The latter finding implicates an upstream kinase acting on Fes, which we identified as Fyn PTK. SCF treatment of BMMCs promoted recruitment of Fes to Kit, potentially via direct interaction of the Fes SH2 domain with phosphorylated Kit. While Fes was not required for SCF-induced signaling to Akt and Erk kinases, Fes-deficient (fes-/-) BMMCs displayed a defect in sustained p38 kinase activation, compared to control cells. SCF-treated Fes-deficient BMMCs also displayed elevated beta1 integrin-mediated cell adhesion and spreading on fibronectin, compared to control cells, and a reduction in cell polarization at later times of SCF treatment. Restoring Fes expression in fes-/- BMMCs by retroviral transduction was sufficient to rescue cell spreading and polarization defects. Interestingly, SCF-induced chemotaxis of BMMCs was also defective in Fes-deficient BMMCs, and restored in Fes-rescue BMMCs. Overall, these results implicate Fes in regulating cross-talk between Kit and beta1 integrins to promote cytoskeletal reorganization and motility of mast cells.

  4. Retinoic acid receptor gamma impacts cellular adhesion, Alpha5Beta1 integrin expression and proliferation in K562 cells.

    Science.gov (United States)

    Kelley, Melissa D; Phomakay, Raynin; Lee, Madison; Niedzwiedz, Victoria; Mayo, Rachel

    2017-01-01

    The interplay between cellular adhesion and proliferation is complex; however, integrins, particularly the α5β1 subset, play a pivotal role in orchestrating critical cellular signals that culminate in cellular adhesion and growth. Retinoids modify the expression of a variety of adhesive/proliferative signaling proteins including α5β1 integrins; however, the role of specific retinoic acid receptors involved in these processes has not been elucidated. In this study, the effect of all-trans-retinoic acid receptor (RAR) agonists on K562 cellular adhesion, proliferation, and α5β1 integrin cell surface expression was investigated. RARγ agonist exposure increased K562 cellular adhesion to RGD containing extracellular matrix proteins fibronectin and FN-120 in a time- and concentration dependent manner, while RARα or RARβ agonist treatment had no effect on cellular adhesion. Due to the novel RARγ- dependent cellular adhesion response exhibited by K562 cells, we examined α5 and β1 integrin subunit expression when K562 cells were exposed to retinoid agonists or vehicle for 24, 48, 72 or 96 hours. Our data demonstrates no differences in K562 cell surface expression of the α5 integrin subunit when cells were exposed to RARα, RARβ, or RARγ agonists for all time points tested. In contrast, RARγ agonist exposure resulted in an increase in cell surface β1 integrin subunit expression within 48 hours that was sustained at 72 and 96 hours. Finally, we demonstrate that while exposure to RARα or RARβ agonists have no effect on K562 cellular proliferation, the RARγ agonist significantly dampens K562 cellular proliferation levels in a time- and concentration- dependent manner. Our study is the first to report that treatment with a RARγ specific agonist augments cellular adhesion to α5β1 integrin substrates, increases cell surface levels of the β1 integrin subunit, and dampens cellular proliferation in a time and concentration dependent manner in a human

  5. The intermediate filament protein vimentin binds specifically to a recombinant integrin α2/β1 cytoplasmic tail complex and co-localizes with native α2/β1 in endothelial cell focal adhesions

    International Nuclear Information System (INIS)

    Kreis, Stephanie; Schoenfeld, Hans-Joachim; Melchior, Chantal; Steiner, Beat; Kieffer, Nelly

    2005-01-01

    Integrin receptors are crucial players in cell adhesion and migration. Identification and characterization of cellular proteins that interact with their short α and β cytoplasmic tails will help to elucidate the molecular mechanisms by which integrins mediate bi-directional signaling across the plasma membrane. Integrin α2β1 is a major collagen receptor but to date, only few proteins have been shown to interact with the α2 cytoplasmic tail or with the α2β1 complex. In order to identify novel binding partners of a α2β1cytoplasmic domain complex, we have generated recombinant GST-fusion proteins, incorporating the leucine zipper heterodimerization cassettes of Jun and Fos. To ascertain proper functionality of the recombinant proteins, interaction with natural binding partners was tested. GST-α2 and GST-Jun α2 bound His-tagged calreticulin while GST-β1 and GST-Fos β1 proteins bound talin. In screening assays for novel binding partners, the immobilized GST-Jun α2/GST-Fos β1 heterodimeric complex, but not the single subunits, interacted specifically with endothelial cell-derived vimentin. Vimentin, an abundant intermediate filament protein, has previously been shown to co-localize with αvβ3-positive focal contacts. Here, we provide evidence that this interaction also occurs with α2β1-enriched focal adhesions and we further show that this association is lost after prolonged adhesion of endothelial cells to collagen

  6. Mac-2 binding protein is a cell-adhesive protein of the extracellular matrix which self-assembles into ring-like structures and binds beta1 integrins, collagens and fibronectin

    DEFF Research Database (Denmark)

    Sasaki, T; Brakebusch, C; Engel, J

    1998-01-01

    Human Mac-2 binding protein (M2BP) was prepared in recombinant form from the culture medium of 293 kidney cells and consisted of a 92 kDa subunit. The protein was obtained in a native state as indicated by CD spectroscopy, demonstrating alpha-helical and beta-type structure, and by protease resis...... in the extracellular matrix of several mouse tissues....... in solid-phase assays to collagens IV, V and VI, fibronectin and nidogen, but not to fibrillar collagens I and III or other basement membrane proteins. The protein also mediated adhesion of cell lines at comparable strength with laminin. Adhesion to M2BP was inhibited by antibodies to integrin beta1...

  7. Interleukin-2 induces beta2-integrin-dependent signal transduction involving the focal adhesion kinase-related protein B (fakB)

    DEFF Research Database (Denmark)

    Brockdorff, J; Kanner, S B; Nielsen, M

    1998-01-01

    beta2 integrin molecules are involved in a multitude of cellular events, including adhesion, migration, and cellular activation. Here, we studied the influence of beta2 integrins on interleukin-2 (IL-2)-mediated signal transduction in human CD4(+) T cell lines obtained from healthy donors...

  8. 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

  9. 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.

  10. The secreted protein ANGPTL2 promotes metastasis of osteosarcoma cells through integrin α5β1, p38 MAPK, and matrix metalloproteinases.

    Science.gov (United States)

    Odagiri, Haruki; Kadomatsu, Tsuyoshi; Endo, Motoyoshi; Masuda, Tetsuro; Morioka, Masaki Suimye; Fukuhara, Shigetomo; Miyamoto, Takeshi; Kobayashi, Eisuke; Miyata, Keishi; Aoi, Jun; Horiguchi, Haruki; Nishimura, Naotaka; Terada, Kazutoyo; Yakushiji, Toshitake; Manabe, Ichiro; Mochizuki, Naoki; Mizuta, Hiroshi; Oike, Yuichi

    2014-01-21

    The tumor microenvironment can enhance the invasive capacity of tumor cells. We showed that expression of angiopoietin-like protein 2 (ANGPTL2) in osteosarcoma (OS) cell lines increased and the methylation of its promoter decreased with time when grown as xenografts in mice compared with culture. Compared with cells grown in normal culture conditions, the expression of genes encoding DNA demethylation-related enzymes increased in tumor cells implanted into mice or grown in hypoxic, serum-starved culture conditions. ANGPTL2 expression in OS cell lines correlated with increased tumor metastasis and decreased animal survival by promoting tumor cell intravasation mediated by the integrin α5β1, p38 mitogen-activated protein kinase, and matrix metalloproteinases. The tolloid-like 1 (TLL1) protease cleaved ANGPTL2 into fragments in vitro that did not enhance tumor progression when overexpressed in xenografts. Expression of TLL1 was weak in OS patient tumors, suggesting that ANGPTL2 may not be efficiently cleaved upon secretion from OS cells. These findings demonstrate that preventing ANGPTL2 signaling stimulated by the tumor microenvironment could inhibit tumor cell migration and metastasis.

  11. Expression by Streptomyces lividans of the Rat α Integrin CD11b A-Domain as a Secreted and Soluble Recombinant Protein

    Directory of Open Access Journals (Sweden)

    Dorra Zouari Ayadi

    2007-01-01

    Full Text Available We already reported the use of a long synthetic signal peptide (LSSP to secrete the Streptomyces sp. TO1 amylase by Streptomyces lividans strain. We herein report the expression and secretion of the rat CD11b A-domain using the same LSSP and S. lividans as host strain. We have used the Escherichia coli/Streptomyces shuttle vector pIJ699 for the cloning of the A-domain DNA sequence downstream of LSSP and under the control of the constitutive ermE-up promoter of Streptomyces erythraeus. Using this construct and S. lividans as a host strain, we achieved the expression of 8 mg/L of soluble secreted recombinant form of the A-domain of the rat leukocyte β2 integrin CD11/CD18 alpha M subunit (CD11b. This secreted recombinant CD11b A-domain reacted with a function blocking antibody showing that this protein is properly folded and probably functional. These data support the capability of Streptomyces to produce heterologous recombinant proteins as soluble secreted form using the “LSSP” synthetic signal peptide.

  12. 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

  13. 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.

  14. 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

  15. Hydrostatic Compress Force Enhances the Viability and Decreases the Apoptosis of Condylar Chondrocytes through Integrin-FAK-ERK/PI3K Pathway

    Science.gov (United States)

    Ma, Dandan; Kou, Xiaoxing; Jin, Jing; Xu, Taotao; Wu, Mengjie; Deng, Liquan; Fu, Lusi; Liu, Yi; Wu, Gang; Lu, Haiping

    2016-01-01

    Reduced mechanical stimuli in many pathological cases, such as hemimastication and limited masticatory movements, can significantly affect the metabolic activity of mandibular condylar chondrocytes and the growth of mandibles. However, the molecular mechanisms for these phenomena remain unclear. In this study, we hypothesized that integrin-focal adhesion kinase (FAK)-ERK (extracellular signal–regulated kinase)/PI3K (phosphatidylinositol-3-kinase) signaling pathway mediated the cellular response of condylar chondrocytes to mechanical loading. Primary condylar chondrocytes were exposed to hydrostatic compressive forces (HCFs) of different magnitudes (0, 50, 100, 150, 200, and 250 kPa) for 2 h. We measured the viability, morphology, and apoptosis of the chondrocytes with different treatments as well as the gene, protein expression, and phosphorylation of mechanosensitivity-related molecules, such as integrin α2, integrin α5, integrin β1, FAK, ERK, and PI3K. HCFs could significantly increase the viability and surface area of condylar chondrocytes and decrease their apoptosis in a dose-dependent manner. HCF of 250 kPa resulted in a 1.51 ± 0.02-fold increase of cell viability and reduced the ratio of apoptotic cells from 18.10% ± 0.56% to 7.30% ± 1.43%. HCFs could significantly enhance the mRNA and protein expression of integrin α2, integrin α5, and integrin β1 in a dose-dependent manner, but not ERK1, ERK2, or PI3K. Instead, HCF could significantly increase phosphorylation levels of FAK, ERK1/2, and PI3K in a dose-dependent manner. Cilengitide, the potent integrin inhibitor, could dose-dependently block such effects of HCFs. HCFs enhances the viability and decreases the apoptosis of condylar chondrocytes through the integrin-FAK-ERK/PI3K pathway. PMID:27827993

  16. 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.

  17. 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...

  18. rLj-RGD3, a Novel Recombinant Toxin Protein from Lampetra japonica, Protects against Cerebral Reperfusion Injury Following Middle Cerebral Artery Occlusion Involving the Integrin-PI3K/Akt Pathway in Rats.

    Directory of Open Access Journals (Sweden)

    Qian Lu

    Full Text Available The RGD-toxin protein Lj-RGD3 is a naturally occurring 118 amino acid peptide that can be obtained from the salivary gland of the Lampetra japonica fish. This unique peptide contains 3 RGD (Arg-Gly-Asp motifs in its primary structure. Lj-RGD3 is available in recombinant form (rLj-RGD3 and can be produced in large quantities using DNA recombination techniques. The pharmacology of the three RGD motif-containing peptides has not been studied. This study investigated the protective effects of rLj-RGD3, a novel polypeptide, against ischemia/reperfusion-induced damage to the brain caused by middle cerebral artery occlusion (MCAO in a rat stroke model. We also explored the mechanism by which rLj-RGD3 acts by measuring protein and mRNA expression levels, with an emphasis on the FAK and integrin-PI3K/Akt anti-apoptosis pathways.rLj-RGD3 was obtained from the buccal secretions of Lampetra japonica using gene recombination technology. Sprague Dawley (SD rats were randomly divided into the following seven groups: a sham group; a vehicle-treated (VT group; 100.0 μg·kg-1, 50.0 μg·kg-1 and 25.0 μg·kg-1 dose rLj-RGD3 groups; and two positive controls, including 1.5 mg·kg-1 Edaravone (ED and 100.0 μg·kg-1 Eptifibatide (EP. MCAO was induced using a model consisting of 2 h of ischemia and 24 h of reperfusion. Behavioral changes were observed in the normal and operation groups after focal cerebral ischemia/reperfusion was applied. In addition, behavioral scores were evaluated at 4 and 24 h after reperfusion. Brain infarct volumes were determined based on 2,3,5-triphenyltetrazolium chloride (TTC staining. Pathological changes in brain tissues were observed using hematoxylin and eosin (H&E staining. Moreover, neuronal apoptosis was detected using terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling (TUNEL assays. We determined the expression levels of focal adhesion kinase (FAK, phosphatidyl inositol 3-kinase (PI3K, protein kinase B

  19. 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

  20. 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

  1. 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

  2. Receptor protein tyrosine phosphatase alpha activates Src-family kinases and controls integrin-mediated responses in fibroblasts

    DEFF Research Database (Denmark)

    Su, J; Muranjan, M; Sap, J

    1999-01-01

    of tyrosine kinases, the activity of which is tightly controlled by inhibitory phosphorylation of a carboxyterminal tyrosine residue (Tyr527 in chicken c-Src); this phosphorylation induces the kinases to form an inactive conformation. Whereas the identity of such inhibitory Tyr527 kinases has been well...... established, no corresponding phosphatases have been identified that, under physiological conditions, function as positive regulators of c-Src and Fyn in fibroblasts. RESULTS: Receptor protein tyrosine phosphatase alpha (RPTPalpha) was inactivated by homologous recombination. Fibroblasts derived from...... these RPTPalpha-/- mice had impaired tyrosine kinase activity of both c-Src and Fyn, and this was accompanied by a concomitant increase in c-Src Tyr527 phosphorylation. RPTPalpha-/- fibroblasts also showed a reduction in the rate of spreading on fibronectin substrates, a trait that is a phenocopy of the effect...

  3. 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.

  4. 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.

  5. 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

  6. 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.

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

    Science.gov (United States)

    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

  8. 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

  9. The Plasma Membrane Sialidase NEU3 Regulates the Malignancy of Renal Carcinoma Cells by Controlling β1 Integrin Internalization and Recycling*

    Science.gov (United States)

    Tringali, Cristina; Lupo, Barbara; Silvestri, Ilaria; Papini, Nadia; Anastasia, Luigi; Tettamanti, Guido; Venerando, Bruno

    2012-01-01

    The human plasma membrane sialidase NEU3 is a key enzyme in the catabolism of membrane gangliosides, is crucial in the regulation of cell surface processes, and has been demonstrated to be significantly up-regulated in renal cell carcinomas (RCCs). In this report, we show that NEU3 regulates β1 integrin trafficking in RCC cells by controlling β1 integrin recycling to the plasma membrane and controlling activation of the epidermal growth factor receptor (EGFR) and focal adhesion kinase (FAK)/protein kinase B (AKT) signaling. NEU3 silencing in RCC cells increased the membrane ganglioside content, in particular the GD1a content, and changed the expression of key regulators of the integrin recycling pathway. In addition, NEU3 silencing up-regulated the Ras-related protein RAB25, which directs internalized integrins to lysosomes, and down-regulated the chloride intracellular channel protein 3 (CLIC3), which induces the recycling of internalized integrins to the plasma membrane. In this manner, NEU3 silencing enhanced the caveolar endocytosis of β1 integrin, blocked its recycling and reduced its levels at the plasma membrane, and, consequently, inhibited EGFR and FAK/AKT. These events had the following effects on the behavior of RCC cells: they (a) decreased drug resistance mediated by the block of autophagy and the induction of apoptosis; (b) decreased metastatic potential mediated by down-regulation of the metalloproteinases MMP1 and MMP7; and (c) decreased adhesion to collagen and fibronectin. Therefore, our data identify NEU3 as a key regulator of the β1 integrin-recycling pathway and FAK/AKT signaling and demonstrate its crucial role in RCC malignancy. PMID:23139422

  10. Quantitation of secretory protein levels by radioimmunoassay

    International Nuclear Information System (INIS)

    Klein, J.L.; Dawson, J.R.

    1978-01-01

    A radioimmunoassay was designed for the detection of secretory protein, a component of secretory immunoglobulin A, in human serum. The assay uses free secretory protein isolated from human colostrum, and antisera raised in rabbits to be purified antigen. The mean level of secretory protein in the control group was 2.34+-0.41 μg/ml (mean+-S.E.M.). The level in cord blood was slightly lower (0.74+-0.26 μg/ml), while the level in patients with ovarian carcinoma was significantly increased (12.67+-1.43 μg/ml). Pregnant women have increasingly secretory protein levels with increasing length of gestation (5.86+-2.02, 11.55+-1.30 and 17.00+-1.16 μg/ml for the first, second and third trimesters, respectively. (Auth.)

  11. The integrin α6β4 as a signaling membrane protein for a damage response to ionizing radiation in human prostate cancer cell lines

    International Nuclear Information System (INIS)

    Woo, Charles; Nagle, Ray B.; Stea, Baldassarre; Cress, Anne E.

    1996-01-01

    Purpose/Object: Integrins are cell surface receptors that exist as heterodimers. The integrin α6β4 is a receptor for laminin and is present in normal human prostate tissue. In prostate carcinoma however, there is loss of β4 expression. Prior studies demonstrated that when a low β4 expressing rectal carcinoma cell line was transfected with β4, the cells underwent apoptosis. We investigated the effects that the β4 integrin had on DNA damage responses in a human prostate carcinoma line. Materials and Methods: DU-145 human prostate carcinoma cells previously selected by us for α6β1 expression were transfected with either a full length β4 construct or vector only. Both cell lines were grown simultaneously and maintained in geneticin for selection purposes. Cells were grown on glass coverslips in 60mm tissue culture dishes under optimal growth conditions. Radiation was delivered using a Co-60 machine with a dose rate of 35 Gy/hr. The cells were given 0, 2, 5, and 10 Gy. Three different radiation damage responses were assayed and include micronuclei (MN) formation, cell cycle distribution, and cell survival. 24 hours after irradiation, the cells were fixed and stained with propidium iodide. Micronuclei formation was detected using a Zeiss LSM10 confocal microscope, and the resulting digital images were analyzed using the NIH Image program. The observed MN were detected without the use of cytochalasin B, but were noted to contain nuclear histone and DNA and were morphologically distinct from apoptotic or necrotic bodies. Results: The quantitative analysis of MN formation revealed a radiation dose dependence of MN formation in both the α6β4 and α6β1 expressing cell lines. The presence of MN 24 hours after irradiation was observed at clinically significant doses (2 Gy) with the largest effect occurring at 5 Gy. The α6β4 expressing cells consistently produced approximately two fold more MN as compared to the α6β1 expressing cells at all radiation doses. The

  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.

    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.

  13. Inhibition on Apoptosis Induced by Elevated Hydrostatic Pressure in Retinal Ganglion Cell-5 via Laminin Upregulating β1-integrin/Focal Adhesion Kinase/Protein Kinase B Signaling Pathway.

    Science.gov (United States)

    Li, Yi; Chen, Yan-Ming; Sun, Ming-Ming; Guo, Xiao-Dan; Wang, Ya-Chen; Zhang, Zhong-Zhi

    2016-04-20

    Glaucoma is a progressive optic neuropathy characterized by degeneration of neurons due to loss of retinal ganglion cells (RGCs). High intraocular pressure (HIOP), the main risk factor, causes the optic nerve damage. However, the precise mechanism of HIOP-induced RGC death is not yet completely understood. This study was conducted to determine apoptosis of RGC-5 cells induced by elevated hydrostatic pressures, explore whether laminin is associated with apoptosis under pressure, whether laminin can protect RGCs from apoptosis and affirm the mechanism that regulates the process of RGCs survival. RGC-5 cells were exposed to 0, 20, 40, and 60 mmHg in a pressurized incubator for 6, 12, and 24 h, respectively. The effect of elevated hydrostatic pressure on RGC-5 cells was measured by Annexin V-fluorescein isothiocyanate/propidium iodide staining, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, and Western blotting of cleaved caspase-3 protein. Location and expression of laminin were detected by immunofluorescence. The expression of β1-integrin, phosphorylation of focal adhesion kinase (FAK) and protein kinase B (PKB, or AKT) were investigated with real-time polymerase chain reaction and Western blotting analysis. Elevated hydrostatic pressure induced apoptosis in cultured RGC-5 cells. Pressure with 40 mmHg for 24 h induced a maximum apoptosis. Laminin was declined in RGC-5 cells after exposing to 40 mmHg for 24 h. After pretreating with laminin, RGC-5 cells survived from elevated pressure. Furthermore, β1-integrin and phosphorylation of FAK and AKT were increased compared to 40 mmHg group. The data show apoptosis tendency of RGC-5 cells with elevated hydrostatic pressure. Laminin can protect RGC-5 cells against high pressure via β1-integrin/FAK/AKT signaling pathway. These results suggest that the decreased laminin of RGC-5 cells might be responsible for apoptosis induced by elevated hydrostatic pressure, and laminin or activating β1-integrin

  14. Dwarfism in mice lacking collagen-binding integrins alpha 2 beta 1 and alpha 11 beta 1 is caused by severely diminished IGF-1 levels

    OpenAIRE

    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 suggest...

  15. 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.

  16. 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

  17. 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

  18. 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.

  19. 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...

  20. 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

  1. 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

  2. Possible involvement of integrin-mediated signalling in oocyte activation: evidence that a cyclic RGD-containing peptide can stimulate protein kinase C and cortical granule exocytosis in mouse oocytes

    Directory of Open Access Journals (Sweden)

    Carbone Maria

    2006-09-01

    Full Text Available Abstract Background Mammalian sperm-oocyte interaction at fertilization involves several combined interactions between integrins on the oocyte and integrin ligands (disintegrins on the sperm. Recent research has indicated the ability of peptides containing the RGD sequence that characterized several sperm disintegrins, to induce intracellular Ca2+ transients and to initiate parthenogenetic development in amphibian and bovine oocytes. In the present study, we investigate the hypothesis that an integrin-associated signalling may participate in oocyte activation signalling by determining the ability of a cyclic RGD-containing peptide to stimulate the activation of protein kinase C (PKC and the exocytosis of cortical granules in mouse oocytes. Methods An In-Vitro-Fertilization assay (IVF was carried in order to test the condition under which a peptide containing the RGD sequence, cyclo(Arg-Gly-Asp-D-Phe-Val, was able to inhibit sperm fusion with zona-free mouse oocytes at metaphase II stage. PKC activity was determined by means of an assay based on the ability of cell lysates to phosphorylate MARKS peptide, a specific PKC substrate. Loss of cortical granules was evaluated by measuring density in the oocyte cortex of cortical granules stained with LCA-biotin/Texas red-streptavidin. In all the experiments, effects of a control peptide containing a non RGD sequence, cyclo(Arg-Ala-Asp-D-Phe-Val, were evaluated. Results The IVF assay revealed that the fusion rate declined significantly when insemination was carried out in the presence of cyclic RGD peptide at concentrations > or = 250 microM (P Conclusion The presents results provide evidence that a cyclic RGD peptide highly effective in inhibiting sperm-oocyte interaction stimulates in mouse oocytes the activation of PKC and the exocytosis of cortical granules. These data support the view that RGD-binding receptors may function as signalling receptors giving rise integrated signalling not sufficient for

  3. 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...

  4. 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

  5. Connective tissue growth factor inhibits gastric cancer peritoneal metastasis by blocking integrin α3β1-dependent adhesion.

    Science.gov (United States)

    Chen, Chiung-Nien; Chang, Cheng-Chi; Lai, Hong-Shiee; Jeng, Yung-Ming; Chen, Chia-I; Chang, King-Jeng; Lee, Po-Huang; Lee, Hsinyu

    2015-07-01

    Connective tissue growth factor (CTGF) plays important roles in normal and pathological conditions. The aim of this study was to investigate the role of CTGF in peritoneal metastasis as well as the underlying mechanism in gastric cancer progression. CTGF expression levels for wild-type and stable overexpression clones were determined by Western blotting and quantitative polymerase chain reaction (Q-PCR). Univariate and multivariate analyses, immunohistochemistry, and survival probability analyses were performed on gastric cancer patients. The extracellular matrix components involved in CTGF-regulated adhesion were determined. Recombinant CTGF was added to cells or coinoculated with gastric cancer cells into mice to evaluate its therapeutic potential. CTGF overexpression and treatment with the recombinant protein significantly inhibited cell adhesion. In vivo peritoneal metastasis demonstrated that CTGF-stable transfectants markedly decreased the number and size of tumor nodules in the mesentery. Statistical analysis of gastric cancer patient data showed that patients expressing higher CTGF levels had earlier TNM staging and a higher survival probability after the surgery. Integrin α3β1 was the cell adhesion molecule mediating gastric cancer cell adhesion to laminin, and blocking of integrin α3β1 prevented gastric cancer cell adhesion to recombinant CTGF. Coimmunoprecipitation results indicated that CTGF binds to integrin α3. Coinoculation of recombinant CTGF and gastric cancer cell lines in mice showed effective inhibition of peritoneal dissemination. Our results suggested that gastric cancer peritoneal metastasis is mediated through integrin α3β1 binding to laminin, and CTGF effectively blocks the interaction by binding to integrin α3β1, thus demonstrating the therapeutic potential of recombinant CTGF in gastric cancer patients.

  6. Inhibition of αvβ3 integrin induces loss of cell directionality of oral squamous carcinoma cells (OSCC.

    Directory of Open Access Journals (Sweden)

    Cyntia F Montenegro

    Full Text Available The connective tissue formed by extracellular matrix (ECM rich in fibronectin and collagen consists a barrier that cancer cells have to overpass to reach blood vessels and then a metastatic site. Cell adhesion to fibronectin is mediated by αvβ3 and α5β1 integrins through an RGD motif present in this ECM protein, thus making these receptors key targets for cell migration studies. Here we investigated the effect of an RGD disintegrin, DisBa-01, on the migration of human fibroblasts (BJ and oral squamous cancer cells (OSCC, SCC25 on a fibronectin-rich environment. Time-lapse images were acquired on fibronectin-coated glass-bottomed dishes. Migration speed and directionality analysis indicated that OSCC cells, but not fibroblasts, showed significant decrease in both parameters in the presence of DisBa-01 (1μM and 2μM. Integrin expression levels of the α5, αv and β3 subunits were similar in both cell lines, while β1 subunit is present in lower levels on the cancer cells. Next, we examined whether the effects of DisBa-01 were related to changes in adhesion properties by using paxillin immunostaining and total internal reflection fluorescence TIRF microscopy. OSCCs in the presence of DisBa-01 showed increased adhesion sizes and number of maturing adhesion. The same parameters were analyzed usingβ3-GFP overexpressing cells and showed that β3 overexpression restored cell migration velocity and the number of maturing adhesion that were altered by DisBa-01. Surface plasmon resonance analysis showed that DisBa-01 has 100x higher affinity for αvβ3 integrin than forα5β1 integrin. In conclusion, our results suggest that the αvβ3 integrin is the main receptor involved in cell directionality and its blockage may be an interesting alternative against metastasis.

  7. 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....

  8. 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.

  9. Hierarchy of ADAM12 binding to integrins in tumor cells

    DEFF Research Database (Denmark)

    Thodeti, Charles Kumar; Fröhlich, Camilla; Nielsen, Christian Kamp

    2005-01-01

    ADAMs (a disintegrin and metalloprotease) comprise a family of cell surface proteins with protease and cell-binding activities. Using different forms and fragments of ADAM12 as substrates in cell adhesion and spreading assays, we demonstrated that alpha9beta1 integrin is the main receptor for ADA...

  10. 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.

  11. αν and β1 Integrins mediate Aβ-induced neurotoxicity in hippocampal neurons via the FAK signaling pathway.

    Directory of Open Access Journals (Sweden)

    Hai-Yan Han

    Full Text Available αν and β1 integrins mediate Aβ-induced neurotoxicity in primary hippocampal neurons. We treated hippocampal neurons with 2.5 µg/mL 17E6 and 5 µg/mL ab58524, which are specific αν and β1 integrin antagonists, respectively, for 42 h prior to 10 µM Aβ treatment. Next, we employed small interfering RNA (siRNA to silence focal adhesion kinase (FAK, a downstream target gene of integrins. The siRNAs were designed with a target sequence, an MOI of 10 and the addition of 5 µg/mL polybrene. Under these conditions, the neurons were transfected and the apoptosis of different cell types was detected. Moreover, we used real-time PCR and Western blotting analyses to detect the expression of FAK and ρFAK genes in different cell types and investigated the underlying mechanism and signal pathway by which αν and β1 integrins mediate Aβ-induced neurotoxicity in hippocampal neurons. An MTT assay showed that both 17E6 and ab58524 significantly increased cell viability compared with the Aβ-treated neurons (P<0.01 and P<0.05, respectively. However, this protective effect was markedly attenuated after transfection with silencing FAK (siFAK. Moreover, TUNEL immunostaining and flow cytometry indicated that both 17E6 and ab58524 significantly protected hippocampal neurons against apoptosis induced by Aβ (P<0.05 compared with the Aβ-treated cells. However, this protective effect was reversed with siFAK treatment. Both the gene and protein expression of FAK increased after Aβ treatment. Interestingly, as the gene and protein levels of FAK decreased, the ρFAK protein expression markedly increased. Furthermore, both the gene and protein expression of FAK and ρFAK were significantly diminished. Thus, we concluded that both αν and β1 integrins interfered with Aβ-induced neurotoxicity in hippocampal neurons and that this mechanism partially contributes to the activation of the Integrin-FAK signaling pathway.

  12. 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.

  13. 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.

  14. 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

  15. 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.

  16. 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.

  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. Soluble CD40 ligand stimulates CD40-dependent activation of the β2 integrin Mac-1 and protein kinase C zeda (PKCζ in neutrophils: implications for neutrophil-platelet interactions and neutrophil oxidative burst.

    Directory of Open Access Journals (Sweden)

    Rong Jin

    Full Text Available Recent work has revealed an essential involvement of soluble CD40L (sCD40L in inflammation and vascular disease. Activated platelets are the major source of sCD40L, which has been implicated in platelet and leukocyte activation, although its exact functional impact on leukocyte-platelet interactions and the underlying mechanisms remain undefined. We aimed to determine the impact and the mechanisms of sCD40L on neutrophils. We studied neutrophil interactions with activated, surface-adherent platelets as a model for leukocyte recruitment to the sites of injury. Our data show that CD40L contributes to neutrophil firm adhesion to and transmigration across activated surface-adherent platelets, possibly through two potential mechanisms. One involves the direct interaction of ligand-receptor (CD40L-CD40, i.e., platelet surface CD40L interaction with neutrophil CD40; another involves an indirect mechanism, i.e. soluble CD40L stimulates activation of the leukocyte-specific β2 integrin Mac-1 in neutrophils and thereby further promotes neutrophil adhesion and migration. Activation of the integrin Mac-1 is known to be critical for mediating neutrophil adhesion and migration. sCD40L activated Mac-1 in neutrophils and enhanced neutrophil-platelet interactions in wild-type neutrophils, but failed to elicit such responses in CD40-deficient neutrophils. Furthermore, our data show that the protein kinase C zeta (PKCζ is critically required for sCD40L-induced Mac-1 activation and neutrophil adhesive function. sCD40L strongly stimulated the focal clustering of Mac-1 (CD11b and the colocalization of Mac-1 with PKCζ in wild-type neutrophils, but had minimal effect in CD40-deficient neutrophils. Blocking PKCζ completely inhibited sCD40L-induced neutrophil firm adhesion. Moreover, sCD40L strongly stimulates neutrophil oxidative burst via CD40-dependent activation of PI3K/NF-KB, but independent of Mac-1 and PKCζ. These findings may contribute to a better

  19. 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

  20. Endotoxin/lipopolysaccharide activates NF-kappa B and enhances tumor cell adhesion and invasion through a beta 1 integrin-dependent mechanism.

    LENUS (Irish Health Repository)

    Wang, Jiang Huai

    2012-02-03

    Beta(1) integrins play a crucial role in supporting tumor cell attachment to and invasion into the extracellular matrix. Endotoxin\\/LPS introduced by surgery has been shown to enhance tumor metastasis in a murine model. Here we show the direct effect of LPS on tumor cell adhesion and invasion in extracellular matrix proteins through a beta(1) integrin-dependent pathway. The human colorectal tumor cell lines SW480 and SW620 constitutively expressed high levels of the beta(1) subunit, whereas various low levels of alpha(1), alpha(2), alpha(4), and alpha(6) expression were detected. SW480 and SW620 did not express membrane-bound CD14; however, LPS in the presence of soluble CD14 (sCD14) significantly up-regulated beta(1) integrin expression; enhanced tumor cell attachment to fibronectin, collagen I, and laminin; and strongly promoted tumor cell invasion through the Matrigel. Anti-beta(1) blocking mAbs (4B4 and 6S6) abrogated LPS- plus sCD14-induced tumor cell adhesion and invasion. Furthermore, LPS, when combined with sCD14, resulted in NF-kappaB activation in both SW480 and SW620 cells. Inhibition of the NF-kappaB pathway significantly attenuated LPS-induced up-regulation of beta(1) integrin expression and prevented tumor cell adhesion and invasion. These results provide direct evidence that although SW480 and SW620 cells do not express membrane-bound CD14, LPS in the presence of sCD14 can activate NF-kappaB, up-regulate beta(1) integrin expression, and subsequently promote tumor cell adhesion and invasion. Moreover, LPS-induced tumor cell attachment to and invasion through extracellular matrix proteins is beta(1) subunit-dependent.

  1. 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...

  2. 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.

  3. Protein C activity and antigen levels in childhood

    NARCIS (Netherlands)

    van Teunenbroek, A.; Peters, M.; Sturk, A.; Borm, J. J.; Breederveld, C.

    1990-01-01

    Hereditary protein C deficiency is an important risk factor for thrombosis. To enable its diagnosis shortly after birth, we determined reference values of protein C antigen and activity levels for the first 3 months of life. To establish an age-related range of protein C levels we also determined

  4. 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.

  5. 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...

  6. 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...

  7. 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

  8. ADAM12/syndecan-4 signaling promotes beta 1 integrin-dependent cell spreading through protein kinase Calpha and RhoA

    DEFF Research Database (Denmark)

    Thodeti, Charles Kumar; Albrechtsen, Reidar; Grauslund, Morten

    2002-01-01

    The ADAMs (a disintegrin and metalloprotease) comprise a large family of multidomain proteins with cell-binding and metalloprotease activities. The ADAM12 cysteine-rich domain (rADAM12-cys) supports cell attachment using syndecan-4 as a primary cell surface receptor that subsequently triggers beta...

  9. RACK1 Targets the Extracellular Signal-Regulated Kinase/Mitogen-Activated Protein Kinase Pathway To Link Integrin Engagement with Focal Adhesion Disassembly and Cell Motility

    Czech Academy of Sciences Publication Activity Database

    Vomastek, Tomáš; Iwanicki, M. P.; Schaeffer, J.; J.; Tarcsafalvi, A.; Parsons, J. T.; Weber, M. J.

    2007-01-01

    Roč. 27, č. 23 (2007), s. 8296-8305 ISSN 0270-7306 R&D Projects: GA AV ČR IAA500200716 Institutional research plan: CEZ:AV0Z50200510 Keywords : protein kinase * adhesion * cell Subject RIV: EE - Microbiology, Virology Impact factor: 6.420, year: 2007

  10. Molecular magnetic resonance imaging of activated hepatic stellate cells with ultrasmall superparamagnetic iron oxide targeting integrin αvβ3 for staging liver fibrosis in rat model

    Directory of Open Access Journals (Sweden)

    Zhang C

    2016-03-01

    Full Text Available Caiyuan Zhang,1,* Huanhuan Liu,1,* Yanfen Cui,1,* Xiaoming Li,1 Zhongyang Zhang,1 Yong Zhang,2 Dengbin Wang1 1Department of Radiology, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, 2MR Advanced Application and Research Center, GE Healthcare China, Shanghai, People’s Republic of China *These authors contributed equally to this work Purpose: To evaluate the expression level of integrin αvβ3 on activated hepatic stellate cells (HSCs at different stages of liver fibrosis induced by carbon tetrachloride (CCl4 in rat model and the feasibility to stage liver fibrosis by using molecular magnetic resonance imaging (MRI with arginine-glycine-aspartic acid (RGD peptide modified ultrasmall superparamagnetic iron oxide nanoparticle (USPIO specifically targeting integrin αvβ3.Materials and methods: All experiments received approval from our Institutional Animal Care and Use Committee. Thirty-six rats were randomly divided into three groups of 12 subjects each, and intraperitoneally injected with CCl4 for either 3, 6, or 9 weeks. Controls (n=10 received pure olive oil. The change in T2* relaxation rate (ΔR2* pre- and postintravenous administration of RGD-USPIO or naked USPIO was measured by 3.0T clinical MRI and compared by one-way analysis of variance or the Student’s t-test. The relationship between expression level of integrin αvβ3 and liver fibrotic degree was evaluated by Spearman’s ranked correlation.Results: Activated HSCs were confirmed to be the main cell types expressing integrin αvβ3 during liver fibrogenesis. The protein level of integrin αv and β3 subunit expressed on activated HSCs was upregulated and correlated well with the progression of liver fibrosis (r=0.954, P<0.001; r=0.931, P<0.001, respectively. After injection of RGD-USPIO, there is significant difference in ΔR2* among rats treated with 0, 3, 6, and 9 weeks of CCl4 (P<0.001. The accumulation of iron particles in fibrotic liver specimen is

  11. 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.

  12. 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.

  13. 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

  14. 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

  15. 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.

  16. Effects of increasing dietary protein levels on growth, feed utilization ...

    African Journals Online (AJOL)

    Yomi

    2012-01-05

    Jan 5, 2012 ... The effect of different dietary protein levels on growth performance and on feed utilization of catfish. (Heterobranchus ... (Legendre, 1991) because of its taste, fast growth rate ..... diet containing 40% protein had high growth with low food intake and feed ... protein rate (45%) combined with a bad utilization of.

  17. 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.

  18. 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.

  19. 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...

  20. 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.

  1. 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.

  2. Hypergravity Stimulates the Extracellular Matrix/Integrin-Signaling Axis and Proliferation in Primary Osteoblasts

    Science.gov (United States)

    Parra, M.; Vercoutere, W.; Roden, C.; Banerjee, I.; Krauser, W.; Holton, E.; Searby, N.; Globus, R.; Almeida, E.

    2003-01-01

    We set out to determine the molecular mechanisms involved in the proliferative response of primary rat osteoblasts to mechanical stimulation using cell culture centrifugation as a model for hypergravity. We hypothesized that this proliferative response is mediated by specific integrin/Extracellular Matrix (ECM) interactions. To investigate this question we developed a cell culture centrifuge and an automated system that performs cell fixation during hypergravity loading. We generated expression vectors for various focal adhesion and cytoskeletal proteins fused to GFP or dsRed and visualized these structures in transfected (or infected) osteoblasts. The actin cytoskeleton was also visualized using rhodamine-phalloidin staining and Focal Adhesion Kinase (FAK) levels were assessed biochemically. We observed that a 24 hour exposure to 50-g stimulated proliferation compared to the 1-g control when cells were plated on fibronectin, collagen Type I , and collagen Type IV, but not on uncoated tissue culture plastic surfaces. This proliferative response was greatest for osteoblasts grown on fibronectin (2-fold increase over 1-g control) and collagen Type I (1.4 fold increase over 1-g control), suggesting that specific matrices and integrins are involved in the signaling pathways required for proliferation. Exposing osteoblasts grown on different matrices to 10-g or 25-g showed that effects on proliferation depended on both matrix type and loading level. We found that osteoblasts exposed to a short pulse of hypergravity during adhesion spread further and had more GFP-FAK containing focal adhesions compared to their 1-g controls. While overall levels of FAK did not change, more FAK was in the active (phosphorylated) form under hypergravity than in the 1-g controls. Cytoskeletal F-actin organization into filaments was also more prominent after brief exposures to hypergravity during the first five minutes of adhesion. These results suggest that specific integrins sense

  3. Changes in Serum Proteins and Creatinine levels in HIV Infected ...

    African Journals Online (AJOL)

    This study examined the level of total serum proteins and globulins in HIV infected Nigerians. 64 patients with HIV infection and 10 apparently healthy subjects were recruited from 3 hospitals in Lagos Metropolis. They were examined for the presence of TB and malaria. Serum total protein, albumin and creatinine levels ...

  4. Kallikrein gene-modified EPCs induce angiogenesis in rats with ischemic hindlimb and correlate with integrin αvβ3 expression.

    Directory of Open Access Journals (Sweden)

    Shen Shen Fu

    Full Text Available BACKGROUND: Human tissue kallikrein (hTK plays an essential role in the physiological and pathological mechanisms of blood vessels. This study aimed to determine whether angiogenesis induced by endothelial progenitor cells (EPCs transduced with the adenovirus-mediated hTK gene could improve blood flow in rat hindlimb ischemia in vivo and to establish a promising mechanism in vitro. METHODS: EPCs transduced with adenovirus encoding hTK-162 (i.e., Ad/hTK-transduced EPCs or Ad/GFP-transduced EPCs were administered to Wister rats with hindlimb ischemia through therapeutic neovascularization. Muscular capillary density (MCD, blood flow (BF, and the number of myofibers were measured at days 7, 14, and 21 after treatment. Expressions of integrin αvβ3 and endothelial nitric oxide synthase (eNOS were detected on the surface of EPCs. RESULTS: MCD, BF, and the number of myofibers in rats with Ad/hTK-transduced EPCs remarkably increased at day 21 after treatment compared with rats with Ad/GFP-transduced EPCs or the control group (P<0.01. Expressions of integrin αvβ3 and eNOS protein on the surface of EPCs also increased in rats with Ad/hTK-transduced EPCs. The levels of integrin αvβ3 expression were reduced by PI3K and eNOS blockade, and the inhibitor of integrin αvβ3 abrogated the migration and adhesion of hTK-transduced EPCs (P<0.05. CONCLUSION: hTK gene delivery in vivo improves the natural angiogenic response to ischemia. The ability of hTK gene-transduced EPCs can be enhanced in vitro, in which integrin αvβ3 plays a role in the process.

  5. Albumin fibrillization induces apoptosis via integrin/FAK/Akt pathway

    Directory of Open Access Journals (Sweden)

    Liang Chi-Ming

    2009-01-01

    Full Text Available Abstract Background Numerous proteins can be converted to amyloid-like fibrils to increase cytotoxicity and induce apoptosis, but the methods generally require a high concentration of protein, vigorous shaking, or fibril seed. As well, the detailed mechanism of the cytotoxic effects is not well characterized. In this study, we have developed a novel process to convert native proteins into the fibrillar form. We used globular bovine serum albumin (BSA as a model protein to verify the properties of the fibrillar protein, investigated its cellular effects and studied the signaling cascade induced by the fibrillar protein. Results We induced BSA, a non-cytotoxic globular protein, to become fibril by a novel process involving Superdex-200 column chromatography in the presence of anionic or zwittergenic detergent(s. The column pore size was more important than column matrix composite in fibril formation. The fibrillar BSA induced apoptosis in BHK-21 cell as well as breast cancer cell line T47D. Pre-treating cells with anti-integrin antibodies blocked the apoptotic effect. Fibrillar BSA, but not globular BSA, bound to integrin, dephosphorylated focal adhesion kinase (FAK, Akt and glycogen synthase kinase-3β (GSK-3β. Conclusion We report on a novel process for converting globular proteins into fibrillar form to cause apoptosis by modulating the integrin/FAK/Akt/GSK-3β/caspase-3 signaling pathway. Our findings may be useful for understanding the pathogenesis of amyloid-like fibrils and applicable for the development of better therapeutic agents that target the underlying mechanism(s of the etiologic agents.

  6. Advancement in integrin facilitated drug delivery.

    Science.gov (United States)

    Arosio, Daniela; Casagrande, Cesare

    2016-02-01

    The research of integrin-targeted anticancer agents has recorded important advancements in ingenious design of delivery systems, based either on the prodrug approach, or on nanoparticle carriers, but for now, none of these has reached a clinical stage of development. Past work in this area has been extensively reviewed by us and others. Thus, the purpose and scope of the present review is to survey the advancement reported in the last 3years, with focus on innovative delivery systems that appear to afford openings for future developments. These systems exploit the labelling with conventional and novel integrin ligands for targeting the interface of cancer cells and of endothelial cells involved in cancer angiogenesis, with the proteins of the extracellular matrix, in the circulation, in tissues, and in tumour stroma, as the site of progression and metastatic evolution of the disease. Furthermore, these systems implement the expertise in the development of nanomedicines to the purpose of achieving preferential biodistribution and uptake in cancer tissues, internalisation in cancer cells, and release of the transported drugs at intracellular sites. The assessment of the value of controlling these factors, and their combination, for future developments requires support of biological testing in appropriate mechanistic models, but also imperatively demand confirmation in therapeutically relevant in vivo models for biodistribution, efficacy, and lack of off-target effects. Thus, among many studies, we have tried to point out the results supported by relevant in vivo studies, and we have emphasised in specific sections those addressing the medical needs of drug delivery to brain tumours, as well as the delivery of oligonucleotides modulating gene-dependent pathological mechanism. The latter could constitute the basis of a promising third branch in the therapeutic armamentarium against cancer, in addition to antibody-based agents and to cytotoxic agents. Copyright © 2015

  7. 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.

  8. 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

  9. 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.

  10. The clinical expression of hereditary protein C and protein S deficiency: : a relation to clinical thrombotic risk-factors and to levels of protein C and protein S

    NARCIS (Netherlands)

    Henkens, C. M. A.; van der Meer, J.; Hillege, J. L.; Bom, V. J. J.; Halie, M. R.; van der Schaaf, W.

    We investigated 103 first-degree relatives of 13 unrelated protein C or protein S deficient patients to assess the role of additional thrombotic risk factors and of protein C and protein S levels in the clinical expression of hereditary protein C and protein S deficiency. Fifty-seven relatives were

  11. 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.

  12. 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

  13. 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.

  14. 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

  15. 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.

  16. Extracellular Membrane-proximal Domain of HAb18G/CD147 Binds to Metal Ion-dependent Adhesion Site (MIDAS) Motif of Integrin β1 to Modulate Malignant Properties of Hepatoma Cells*

    Science.gov (United States)

    Li, Yong; Wu, Jiao; Song, Fei; Tang, Juan; Wang, Shi-Jie; Yu, Xiao-Ling; Chen, Zhi-Nan; Jiang, Jian-Li

    2012-01-01

    Several lines of evidence suggest that HAb18G/CD147 interacts with the integrin variants α3β1 and α6β1. However, the mechanism of the interaction remains largely unknown. In this study, mammalian protein-protein interaction trap (MAPPIT), a mammalian two-hybrid method, was used to study the CD147-integrin β1 subunit interaction. CD147 in human hepatocellular carcinoma (HCC) cells was interfered with by small hairpin RNA. Nude mouse xenograft model and metastatic model of HCC were used to detect the role of CD147 in carcinogenesis and metastasis. We found that the extracellular membrane-proximal domain of HAb18G/CD147 (I-type domain) binds at the metal ion-dependent adhesion site in the βA domain of the integrin β1 subunit, and Asp179 in the I-type domain of HAb18G/CD147 plays an important role in the interaction. The levels of the proteins that act downstream of integrin, including focal adhesion kinase (FAK) and phospho-FAK, were decreased, and the cytoskeletal structures of HCC cells were rearranged bearing the HAb18G/CD147 deletion. Simultaneously, the migration and invasion capacities, secretion of matrix metalloproteinases, colony formation rate in vitro, and tumor growth and metastatic potential in vivo were decreased. These results indicate that the interaction of HAb18G/CD147 extracellular I-type domain with the integrin β1 metal ion-dependent adhesion site motif activates the downstream FAK signaling pathway, subsequently enhancing the malignant properties of HCC cells. PMID:22130661

  17. Dietary protein level and performance of growing Baladi kids.

    Science.gov (United States)

    Abdelrahman, M M; Aljumaah, R S

    2014-01-01

    A study was conducted to evaluate the effect of feeding different levels of protein to black Baladi breed kids. Weanling Baladi kids (n=18; 75 to 90 days old) were selected and individually housed at our experimental farm. Kids were divided randomly to one of the three treatments for 12 weeks. The three dietary treatments were: T1: control ration, formulated according to NRC to cover the protein (level 1) and other nutrients requirements. T2: ration formulated to cover only 75% of protein (level 2) recommended by NRC. T3: control diet + 2.4 g undegradable methionine (Smartamine®)/day/kid (level 3). Feed intake, initial and monthly body weights were recorded. Blood samples were collected monthly and analyzed for metabolites and Co, Zn and Cu levels. Decreasing the dietary level of protein (T2) negatively affected (Pkids below the NRC requirements of protein negatively affect the growth performance and feed efficiency. The recommended protein level by NRC for growing kids cover the requirements of growing black Baladi kids for maximum growth and productivity.

  18. Effect Of Dietary Protein Levels On The Performance And Carcass ...

    African Journals Online (AJOL)

    Effect Of Dietary Protein Levels On The Performance And Carcass ... Nigerian Journal of Animal Production ... Response criteria such as weight gain and feed conversion ratio, among others, and carcass characteristics were measured.

  19. 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.

  20. 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...

  1. 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.

  2. 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...

  3. Protein Expression Analyses at the Single Cell Level

    Directory of Open Access Journals (Sweden)

    Masae Ohno

    2014-09-01

    Full Text Available The central dogma of molecular biology explains how genetic information is converted into its end product, proteins, which are responsible for the phenotypic state of the cell. Along with the protein type, the phenotypic state depends on the protein copy number. Therefore, quantification of the protein expression in a single cell is critical for quantitative characterization of the phenotypic states. Protein expression is typically a dynamic and stochastic phenomenon that cannot be well described by standard experimental methods. As an alternative, fluorescence imaging is being explored for the study of protein expression, because of its high sensitivity and high throughput. Here we review key recent progresses in fluorescence imaging-based methods and discuss their application to proteome analysis at the single cell level.

  4. 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.

  5. 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...

  6. 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.

  7. Liquid-Diet with Alcohol Alters Maternal, Fetal and Placental Weights and the Expression of Molecules Involved in Integrin Signaling in the Fetal Cerebral Cortex

    Directory of Open Access Journals (Sweden)

    Ujjwal K. Rout

    2010-11-01

    Full Text Available Maternal alcohol consumption during pregnancy causes wide range of behavioral and structural deficits in children, commonly known as Fetal Alcohol Syndrome (FAS. Children with FAS may suffer behavioral deficits in the absence of obvious malformations. In rodents, the exposure to alcohol during gestation changes brain structures and weights of offspring. The mechanism of FAS is not completely understood. In the present study, an established rat (Long-Evans model of FAS was used. The litter size and the weights of mothers, fetuses and placentas were examined on gestation days 18 or 20. On gestation day 18, the effects of chronic alcohol on the expression levels of integrin receptor subunits, phospholipase-Cγ and N-cadherin were examined in the fetal cerebral cortices. Presence of alcohol in the liquid-diet reduced the consumption and decreased weights of mothers and fetuses but increased the placental weights. Expression levels of β1 and α3 integrin subunits and phospholipase-Cγ2 were significantly altered in the fetal cerebral cortices of mothers on alcohol containing diet. Results show that alcohol consumption during pregnancy even with protein, mineral and vitamin enriched diet may affect maternal and fetal health, and alter integrin receptor signaling pathways in the fetal cerebral cortex disturbing the development of fetal brains.

  8. 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...

  9. HIV-1 Tat protein induces glial cell autophagy through enhancement of BAG3 protein levels.

    Science.gov (United States)

    Bruno, Anna Paola; De Simone, Francesca Isabella; Iorio, Vittoria; De Marco, Margot; Khalili, Kamel; Sariyer, Ilker Kudret; Capunzo, Mario; Nori, Stefania Lucia; Rosati, Alessandra

    2014-01-01

    BAG3 protein has been described as an anti-apoptotic and pro-autophagic factor in several neoplastic and normal cells. We previously demonstrated that BAG3 expression is elevated upon HIV-1 infection of glial and T lymphocyte cells. Among HIV-1 proteins, Tat is highly involved in regulating host cell response to viral infection. Therefore, we investigated the possible role of Tat protein in modulating BAG3 protein levels and the autophagic process itself. In this report, we show that transfection with Tat raises BAG3 levels in glioblastoma cells. Moreover, BAG3 silencing results in highly reducing Tat- induced levels of LC3-II and increasing the appearance of sub G0/G1 apoptotic cells, in keeping with the reported role of BAG3 in modulating the autophagy/apoptosis balance. These results demonstrate for the first time that Tat protein is able to stimulate autophagy through increasing BAG3 levels in human glial cells.

  10. 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.

  11. Low levels of foot-and-mouth disease virus 3C protease expression are required to achieve optimal capsid protein expression and processing in mammalian cells

    DEFF Research Database (Denmark)

    Polacek, Charlotta; Gullberg, Maria; Li, Jiong

    2013-01-01

    transient-expression assays, within mammalian cells, it is possible to modify the relative amounts of the substrate and protease. It has now been shown that optimal production of the processed capsid proteins from P1-2A is achieved with reduced levels of 3Cpro expression, relative to the P1-2A, compared...... detected by FMDV antigen detection assays. Furthermore, the P1-2A and the processed forms each bind to the integrin αvβ6, the major FMDV receptor. These results contribute to the development of systems which efficiently express the components of empty capsid particles and may represent the basis for safer...... production of diagnostic reagents and improved vaccines against foot-and-mouth disease....

  12. α2 Integrin, extracellular matrix metalloproteinase inducer, and matrix metalloproteinase-3 act sequentially to induce differentiation of mouse embryonic stem cells into odontoblast-like cells

    International Nuclear Information System (INIS)

    Ozeki, Nobuaki; Kawai, Rie; Hase, Naoko; Hiyama, Taiki; Yamaguchi, Hideyuki; Kondo, Ayami; Nakata, Kazuhiko; Mogi, Makio

    2015-01-01

    We previously reported that interleukin 1β acts via matrix metalloproteinase (MMP)-3 to regulate cell proliferation and suppress apoptosis in α2 integrin-positive odontoblast-like cells differentiated from mouse embryonic stem (ES) cells. Here we characterize the signal cascade underpinning odontoblastic differentiation in mouse ES cells. The expression of α2 integrin, extracellular matrix metalloproteinase inducer (Emmprin), and MMP-3 mRNA and protein were all potently increased during odontoblastic differentiation. Small interfering RNA (siRNA) disruption of the expression of these effectors potently suppressed the expression of the odontoblastic biomarkers dentin sialophosphoprotein, dentin matrix protein-1 and alkaline phosphatase, and blocked odontoblast calcification. Our siRNA, western blot and blocking antibody analyses revealed a unique sequential cascade involving α2 integrin, Emmprin and MMP-3 that drives ES cell differentiation into odontoblasts. This cascade requires the interaction between α2 integrin and Emmprin and is potentiated by exogenous MMP-3. Finally, although odontoblast-like cells potently express α2, α6, αV, β1, and β3, integrins, we confirmed that β1 integrin acts as the trigger for ES cell differentiation, apparently in complex with α2 integrin. These results demonstrate a unique and unanticipated role for an α2 integrin-, Emmprin-, and MMP-3-mediated signaling cascade in driving mouse ES cell differentiation into odontoblast-like cells. - Highlights: • Odontoblast differentiation requires activation of α2 integrin, Emmprin and MMP-3. • α2 integrin, Emmprin and MMP-3 form a sequential signaling cascade. • β1 integrin acts a specific trigger for odontoblast differentiation. • The role of these effectors is highly novel and unanticipated

  13. α2 Integrin, extracellular matrix metalloproteinase inducer, and matrix metalloproteinase-3 act sequentially to induce differentiation of mouse embryonic stem cells into odontoblast-like cells

    Energy Technology Data Exchange (ETDEWEB)

    Ozeki, Nobuaki; Kawai, Rie; Hase, Naoko; Hiyama, Taiki; Yamaguchi, Hideyuki [Department of Endodontics, School of Dentistry, Aichi Gakuin University, Nagoya, Aichi 464-8651 (Japan); Kondo, Ayami [Department of Medicinal Biochemistry, School of Pharmacy, Aichi Gakuin University, Nagoya 464-8650 (Japan); Nakata, Kazuhiko [Department of Endodontics, School of Dentistry, Aichi Gakuin University, Nagoya, Aichi 464-8651 (Japan); Mogi, Makio, E-mail: makio@dpc.agu.ac.jp [Department of Medicinal Biochemistry, School of Pharmacy, Aichi Gakuin University, Nagoya 464-8650 (Japan)

    2015-02-01

    We previously reported that interleukin 1β acts via matrix metalloproteinase (MMP)-3 to regulate cell proliferation and suppress apoptosis in α2 integrin-positive odontoblast-like cells differentiated from mouse embryonic stem (ES) cells. Here we characterize the signal cascade underpinning odontoblastic differentiation in mouse ES cells. The expression of α2 integrin, extracellular matrix metalloproteinase inducer (Emmprin), and MMP-3 mRNA and protein were all potently increased during odontoblastic differentiation. Small interfering RNA (siRNA) disruption of the expression of these effectors potently suppressed the expression of the odontoblastic biomarkers dentin sialophosphoprotein, dentin matrix protein-1 and alkaline phosphatase, and blocked odontoblast calcification. Our siRNA, western blot and blocking antibody analyses revealed a unique sequential cascade involving α2 integrin, Emmprin and MMP-3 that drives ES cell differentiation into odontoblasts. This cascade requires the interaction between α2 integrin and Emmprin and is potentiated by exogenous MMP-3. Finally, although odontoblast-like cells potently express α2, α6, αV, β1, and β3, integrins, we confirmed that β1 integrin acts as the trigger for ES cell differentiation, apparently in complex with α2 integrin. These results demonstrate a unique and unanticipated role for an α2 integrin-, Emmprin-, and MMP-3-mediated signaling cascade in driving mouse ES cell differentiation into odontoblast-like cells. - Highlights: • Odontoblast differentiation requires activation of α2 integrin, Emmprin and MMP-3. • α2 integrin, Emmprin and MMP-3 form a sequential signaling cascade. • β1 integrin acts a specific trigger for odontoblast differentiation. • The role of these effectors is highly novel and unanticipated.

  14. 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.

  15. 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.

  16. Investigation of the connection between the quality of protein, protein level and endogenous N excretion

    International Nuclear Information System (INIS)

    Koehler, R.; Gebhardt, G.

    1979-01-01

    The influence of various protein qualities as well as of different levels of protein on the amount of endogenous N excretion, metabolic fecal nitrogen (MFN) and endogenous urinary N (EUN) was determined in growing albino rats. The test rations were labelled with admixtures of 15 N-DL-methionine and 15 N-DL-lysine, respectively, or contained feed protein enriched with 15 N. EUN and MFN and their sum (the N maintenance requirement) showed the influence of the respective protein source and its dependence on the protein level. The endogenous N excretions showed an opposite tendency to the N balance; for high-quality protein feedstuffs with a high N balance (e.g. dried eggs) they are lower than for protein sources of inferior quality, with a low N-balance only (e.g. wheat gluten). Presumably this interaction of retention and maintenance is due to the complementary effect of exogenous and endogenous amino acids in the N and amino acid pool, respectively. Provided that the N dose and the live weight of the animals are comparable, the N balance appears to be more suitable as parameter for the description of the protein quality and the calculation of the protein utilisation than N retention, as the sum of N balance and the values of MFN and EUN (depending on the feedstuffs and the N level). (author)

  17. 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

  18. Human serum protein and C-reactive protein levels among HIV ...

    African Journals Online (AJOL)

    Human serum protein and C-reactive protein levels were determined among HIV patients visiting St Camillus Hospital, Uromi, Edo State, Nigeria, between January to March, 2013. Fifty (50) HIV patients (20 males; 30 females) and 50 control subjects (24 males; 26 females) were enrolled for this study. The clinical status of ...

  19. 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.

  20. 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...

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

    DEFF Research Database (Denmark)

    Couchman, J R; Woods, A

    1999-01-01

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

  2. Morus alba Leaf Lectin (MLL) Sensitizes MCF-7 Cells to Anoikis by Inhibiting Fibronectin Mediated Integrin-FAK Signaling through Ras and Activation of P38 MAPK

    Science.gov (United States)

    Saranya, Jayaram; Shilpa, Ganesan; Raghu, Kozhiparambil G.; Priya, Sulochana

    2017-01-01

    Lectins are a unique class of carbohydrate binding proteins/glycoproteins, and many of them possess anticancer properties. They can induce cell cycle arrest and apoptosis, inhibit protein synthesis, telomerase activity and angiogenesis in cancer cells. In the present study, we have demonstrated the effect of Morus alba leaf lectin (MLL) on anoikis induction in MCF-7 cells. Anoikis induction in cancer cells has a significant role in preventing early stage metastasis. MLL treatment in monolayers of MCF-7 cells caused significant detachment of cells in a time and concentration dependent manner. The detached cells failed to re-adhere and grew even to culture plates coated with different matrix proteins. DNA fragmentation, membrane integrity studies, annexin V staining, caspase 9 activation and upregulation of Bax/Bad confirmed that the detached cells underwent apoptosis. Upregulation of matrix metalloproteinase 9 (MMP-9) caused a decrease in fibronectin (FN) production which facilitated the cells to detach by blocking the FN mediated downstream signaling. On treatment with MLL, we have observed downregulation of integrin expression, decreased phosphorylation of focal adhesion kinase (FAK), loss in FAK-integrin interaction and active Ras. MLL treatment downregulated the levels of phosphorylated Akt and PI3K. Also, we have studied the effect of MLL on two stress activated protein kinases p38 MAPK and JNK. p38 MAPK activation was found to be elevated, but there was no change in the level of JNK. Thus our study substantiated the possible antimetastatic effect of MLL by inducing anoikis in MCF-7 cells by activation of caspase 9 and proapoptotic Bax/Bad by blockage of FN mediated integrin/FAK signaling and partly by activation of p38 MAPK. PMID:28223935

  3. Synchronized integrin engagement and chemokine activation is crucial in neutrophil extracellular trap-mediated sterile inflammation

    NARCIS (Netherlands)

    Rossaint, Jan; Herter, Jan M.; van Aken, Hugo; Napirei, Markus; Döring, Yvonne; Weber, Christian; Soehnlein, Oliver; Zarbock, Alexander

    2014-01-01

    There is emerging evidence that neutrophil extracellular traps (NETs) play important roles in inflammatory processes. Here we report that neutrophils have to be simultaneously activated by integrin-mediated outside-in- and G-protein-coupled receptor (GPCR) signaling to induce NET formation in acute

  4. High-level transient expression of recombinant protein in lettuce.

    Science.gov (United States)

    Joh, Lawrence D; Wroblewski, Tadeusz; Ewing, Nicholas N; VanderGheynst, Jean S

    2005-09-30

    Transient expression following agroinfiltration of plant tissue was investigated as a system for producing recombinant protein. As a model system, Agrobacterium tumefaciens containing the beta-glucuronidase (GUS) gene was vacuum infiltrated into lettuce leaf disks. Infiltration with a suspension of 10(9) colony forming units/mL followed by incubation for 72 h at 22 degrees C in continuous darkness produced a maximum of 0.16% GUS protein based on dry tissue or 1.1% GUS protein based on total soluble protein. This compares favorably to expression levels for commercially manufactured GUS protein from transgenic corn seeds. A. tumefaciens culture medium pH between 5.6 and 7.0 and surfactant concentrations lettuce to produce GUS protein more rapidly, but final levels did not exceed the GUS production in leaves incubated in continuous darkness after 72 h at 22 degrees C. The kinetics of GUS expression during incubation in continuous light and dark were represented well using a logistic model, with rate constants of 0.30 and 0.29/h, respectively. To semi-quantitatively measure the GUS expression in large numbers of leaf disks, a photometric enhancement of the standard histochemical staining method was developed. A linear relationship with an R2 value of 0.90 was determined between log10 (% leaf darkness) versus log10 (GUS activity). Although variability in expression level was observed, agroinfiltration appears to be a promising technology that could potentially be scaled up to produce high-value recombinant proteins in planta. Copyright 2005 Wiley Periodicals, Inc

  5. Structure-Guided Design of a High-Affinity Platelet Integrin αIIbβ3 Receptor Antagonist That Disrupts Mg2+ Binding to the MIDAS | Center for Cancer Research

    Science.gov (United States)

    A Better Fit. An improved anticoagulant drug called RUC-2 (ball and stick structure) fits snugly into its binding pocket on integrin (blue), a protein found on the surface of platelets. RUC-2 binds both subunits of integrin, inhibiting the excessive blood coagulation that can lead to strokes and heart attacks. Unlike similar drugs that alter integrin's structure when they bind and trigger unwanted immune responses, RUC-2 does not disturb the configuration of its larger partner.

  6. 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.

  7. 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...

  8. Association of plasma protein C levels and coronary artery disease ...

    African Journals Online (AJOL)

    Several studies have shown the risk factor causes of coronary heart disease. In this study we tested the hypothesis that plasma protein C level might be used as a biomarker for coronary heart disease and myocardial infarction. The study included 60 men that were classified into 3 groups according to clinical examination; ...

  9. Serum protein and enzyme levels in rats following administration of ...

    African Journals Online (AJOL)

    The effects of caffeinated and non-caffeinated paracetamol administration, with or without vitamins A and E supplementation on the protein and enzyme levels in Wistar albino rats were investigated using cafeinated paracetamol and paracetamol as caffeinated and non-caffeinated paracetamol respectively, and water ...

  10. Effect Of Different Protein Levels on The Performance Of Growing ...

    African Journals Online (AJOL)

    T4 was superior to other treatments in terms of feed to gain ratio, efficiency of feed utilization and reproductive performance. Snails in T1 with 10% CP failed to lay eggs and had the least developed reproductive system. A diet of 15-20% C. P is therefore recommended for growing snails. Key words: Protein levels, snails, ...

  11. Interactive effect of dietary protein level and zilpaterol hydrochloride ...

    African Journals Online (AJOL)

    Bonsmara type steers were used to determine the effect of dietary zilpaterol hydrochloride (ZH) in combination with different dietary crude protein (CP) levels (100, 120 and 140 g CP/kg) on growth performance and meat quality. Treatment groups (T) consisted of 12 steers each. T1 – 100 g CP/kg + 0.15 mg ZH/kg live weight ...

  12. Effect Of Crude Protein Levels And Follicle Stimulation On Egg ...

    African Journals Online (AJOL)

    Two groups received 16% crude protein (CP) level diets and the other two groups, 32%. One each of the two groups received follicle stimulation, induced by administration of Clomifene citrate (1.5mg/kg) via cathetered 5ml syringe through the 10week experimental period, with feed and water offered ad libitum.

  13. Effect of dietary crude protein level on the performance and ...

    African Journals Online (AJOL)

    ویرایه

    2013-06-26

    Jun 26, 2013 ... The effects of increasing dietary levels of crude protein (CP) on growth, feed intake, feed efficiency and nutrient apparent ... matter intake (DMI) than the kids fed with 10.5, 12.8, .... Food and Agriculture Organization. Database ...

  14. Ofloxacin induces apoptosis via β1 integrin-EGFR-Rac1-Nox2 pathway in microencapsulated chondrocytes

    International Nuclear Information System (INIS)

    Sheng, Zhi-Guo; Huang, Wei; Liu, Yu-Xiang; Yuan, Ye; Zhu, Ben-Zhan

    2013-01-01

    Quinolones (QNs)-induced arthropathy is an important toxic side-effect in immature animals leading to the restriction of their therapeutic use in pediatrics. Ofloxacin, a typical QN, was found to induce the chondrocytes apoptosis in the early phase (12–48 h) of arthropathy in our previous study. However, the exact mechanism(s) is unclear. Microencapsulated juvenile rabbit joint chondrocytes, a three-dimensional culture system, is utilized to perform the present study. Ofloxacin, at a therapeutically relevant concentration (10 μg/ml), disturbs the interaction between β1 integrin and activated intracellular signaling proteins at 12 h, which is inhibited when supplementing Mg 2+ . Intracellular reactive oxygen species (ROS) significantly increases in a time-dependent manner after exposure to ofloxacin for 12–48 h. Furthermore, ofloxacin markedly enhances the level of activated Rac1 and epidermal growth factor receptor (EGFR) phosphorylation, and its inhibition in turn reduces the ROS production, apoptosis and Rac1 activation. Silencing Nox2, Rac1 or supplementing Mg 2+ inhibits ROS accumulation, apoptosis occurrence and EGFR phosphorylation induced by ofloxacin. However, depletion of Nox2, Rac1 and inhibition of EGFR do not affect ofloxacin-mediated loss of interaction between β1 integrin and activated intracellular signaling proteins. In addition, ofloxacin also induces Vav2 phosphorylation, which is markedly suppressed after inactivating EGFR or supplementing Mg 2+ . These results suggest that ofloxacin causes Nox2-mediated intracellular ROS production by disrupting the β1 integrin function and then activating the EGFR-Vav2-Rac1 pathway, finally resulting in apoptosis within 12–48 h exposure. The present study provides a novel insight regarding the potential role of Nox-driven ROS in QNs-induced arthropathy. - Highlights: ► Ofloxacin induces Nox2-driven ROS in encapsulated chondrocyte at 12–48 h. ► Ofloxacin stimulates ROS production via the β1

  15. Ofloxacin induces apoptosis via β1 integrin-EGFR-Rac1-Nox2 pathway in microencapsulated chondrocytes

    Energy Technology Data Exchange (ETDEWEB)

    Sheng, Zhi-Guo [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Science, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing 100085 (China); Huang, Wei [Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University Health Science Center, Beijing 1000191 (China); Liu, Yu-Xiang [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Science, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing 100085 (China); Yuan, Ye [Beijing Institute of Pharmacology and Toxicology, 27 Taiping Road, Beijing 100850 (China); Zhu, Ben-Zhan, E-mail: bzhu@rcees.ac.cn [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Science, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing 100085 (China); Linus Pauling Institute, Oregon State University, Corvallis, OR 97331 (United States)

    2013-02-15

    Quinolones (QNs)-induced arthropathy is an important toxic side-effect in immature animals leading to the restriction of their therapeutic use in pediatrics. Ofloxacin, a typical QN, was found to induce the chondrocytes apoptosis in the early phase (12–48 h) of arthropathy in our previous study. However, the exact mechanism(s) is unclear. Microencapsulated juvenile rabbit joint chondrocytes, a three-dimensional culture system, is utilized to perform the present study. Ofloxacin, at a therapeutically relevant concentration (10 μg/ml), disturbs the interaction between β1 integrin and activated intracellular signaling proteins at 12 h, which is inhibited when supplementing Mg{sup 2+}. Intracellular reactive oxygen species (ROS) significantly increases in a time-dependent manner after exposure to ofloxacin for 12–48 h. Furthermore, ofloxacin markedly enhances the level of activated Rac1 and epidermal growth factor receptor (EGFR) phosphorylation, and its inhibition in turn reduces the ROS production, apoptosis and Rac1 activation. Silencing Nox2, Rac1 or supplementing Mg{sup 2+} inhibits ROS accumulation, apoptosis occurrence and EGFR phosphorylation induced by ofloxacin. However, depletion of Nox2, Rac1 and inhibition of EGFR do not affect ofloxacin-mediated loss of interaction between β1 integrin and activated intracellular signaling proteins. In addition, ofloxacin also induces Vav2 phosphorylation, which is markedly suppressed after inactivating EGFR or supplementing Mg{sup 2+}. These results suggest that ofloxacin causes Nox2-mediated intracellular ROS production by disrupting the β1 integrin function and then activating the EGFR-Vav2-Rac1 pathway, finally resulting in apoptosis within 12–48 h exposure. The present study provides a novel insight regarding the potential role of Nox-driven ROS in QNs-induced arthropathy. - Highlights: ► Ofloxacin induces Nox2-driven ROS in encapsulated chondrocyte at 12–48 h. ► Ofloxacin stimulates ROS production via

  16. 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

  17. The Cutoff Level for Urine Protein in Urine Immunofixation Electrophoresis.

    Science.gov (United States)

    Ellidag, Hamit Yasar; Curek, Gulten; Eren, Esin; Aydin, Ozgur; Yilmaz, Necat

    2015-01-01

    Immunofixation electrophoresis (IFE) maintains its importance in diagnosing monoclonal gammopathies. In particular, urine IFE detects free light chains (FLC) in urine samples even at low concentrations and offers higher sensitivity compared to serum electrophoresis and serum IFE. The aim of the present study was to determine the place and significance of quantitative urinary protein measurement before IFE in interpreting the results of subsequent IFE and to determine the most appropriate protein concentrations for the appearance of bands. The records of a total of 600 patients, who underwent screening for Bence Jones proteinuria using IFE on 24-hour urine, were retrospectively reviewed. Urine IFE was performed using Helena SAS-I and SAS-I devices. The total protein concentration in the urine was quantitatively determined by the Pyrogallol red method, and the urine albumin level was determined using the immunoturbidimetric method. These analyses were measured on an Olympus/Beckmann AU5800. The evaluation of IFE results revealed that 311 patients had normal results, 108 patients had monoclonal bands, five patients had biclonal bands, 28 had polyclonal bands, and 148 patients had various degrees of proteinuria. ROC curves were created in order to determine the most appropriate urinary protein and albumin levels to observe bands in IFE. Accordingly, urine baseline protein level (mg/dL) showed the highest AUC value (cutoff value: 19.4 mg/dL, sensitivity: 92%, specificity: 98.2%, AUC: 0.972). The present study showed that quantitative protein measurement before IFE eliminated the disadvantages associated with the IFE method and its interpretation.

  18. 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.

  19. Proteins in Complementary Food: What Is the Healthiest Level?

    Directory of Open Access Journals (Sweden)

    О. K. Netrebenko

    2015-01-01

    Full Text Available Adequate protein consumption in infants is a heavily debated issue. First, it is related to the formation of a new scientific field — “Infant prerequisites of man’s wellness and illness,” which directly indicates that excessive intake of proteins during infancy has long-term consequences and greatly contributes to obesity and chronic infectious diseases in adults; second, it is related to new technologies, which improve the protein component of infant formulas and bring them at par with breast milk in terms of quality and quantity. High protein consumption is related to bottle feeding, because starter and further infant formulas are richer in protein than breast milk. Protein-rich menus trigger production of insulinogenic amino acids, insulin and the insulin-like growth factor (IGF-1. High IFTcombined with branched-chain amino acids (leucine, valine, isoleucine, threonine activates a set of signalling molecules (mTOR, which are responsible for integrating metabolic and immune response. Repeated activation of mTOR coupled with regular intake of high-protein infant formulas causes health issues in adulthood. Diseases like diabetes type 2, obesity, arterial hypertension, cancer (particularly prostatic cancer, are related to overactivation of the mTOR signalling molecule complex. Intensive consumption of milk in today’s world is the key mTOR activator contributing to an increased risk of lifestyle diseases and triggering the mechanism of their development. The progressing infant formula industry allows to cut protein levels in starter and further infant formulas down to 12 g/l and, respectively, lower the risk of non-infectious diseases in adulthood. 

  20. 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...

  1. Genetic and environmental influences of surfactant protein D serum levels

    DEFF Research Database (Denmark)

    Sørensen, Grith Lykke; Hjelmborg, Jacob v. B.; Kyvik, Kirsten Ohm

    2006-01-01

    in the NH(2)-terminal region (Met11Thr) of the mature protein is significantly associated with the serum SP-D levels. A classic twin study was performed on a twin population including 1,476 self-reported healthy adults. The serum SP-D levels increased with male sex, age, and smoking status. The intraclass...... defining the constitutional serum level of SP-D and determine the magnitude of the genetic contribution to serum SP-D in the adult population. Recent studies have demonstrated that serum SP-D concentrations in children are genetically determined and that a single nucleotide polymorphism (SNP) located...

  2. Genetic and environmental influences of surfactant protein D serum levels

    DEFF Research Database (Denmark)

    Sorensen, G.L.; Hjelmborg, J.V.; Kyvik, K.O.

    2006-01-01

    defining the constitutional serum level of SP-D and determine the magnitude of the genetic contribution to serum SP-D in the adult population. Recent studies have demonstrated that serum SP-D concentrations in children are genetically determined and that a single nucleotide polymorphism (SNP) located...... in the NH(2)-terminal region (Met11Thr) of the mature protein is significantly associated with the serum SP-D levels. A classic twin study was performed on a twin population including 1,476 self-reported healthy adults. The serum SP-D levels increased with male sex, age, and smoking status. The intraclass...

  3. Total proteins and protein fractions levels in pregnant rats subjected to whole-body gamma irradiation

    International Nuclear Information System (INIS)

    Mansour, M.A.; Roushdy, H.M.; Mazhar, F.M.; Abu-Gabal, H.A.

    1986-01-01

    A total number of 180 mature rats (120 females and 60 males) weighing from 120-140 g were used to study the effect of two doses (2 and 4 Gy) whole-body gamma irradiation on the level of total protein and protein fractions in serum of pregnant rats during the period of organogenesis. It was found that the levels of total protein, albumin and gamma globulins significantly decreased according to the doses of exposure. The levels of alpha and beta globulins significantly increased more in the serum of rats exposed to 2 Gy than in rats exposed to 4 Gy. The level of A/G ratio significantly decreased more in the serum of rats exposed to 2Gy than in those exposed to 4 Gy

  4. 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.

  5. 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

  6. 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.

  7. Low copper and high manganese levels in prion protein plaques

    Science.gov (United States)

    Johnson, Christopher J.; Gilbert, P.U.P.A.; Abrecth, Mike; Baldwin, Katherine L.; Russell, Robin E.; Pedersen, Joel A.; McKenzie, Debbie

    2013-01-01

    Accumulation of aggregates rich in an abnormally folded form of the prion protein characterize the neurodegeneration caused by transmissible spongiform encephalopathies (TSEs). The molecular triggers of plaque formation and neurodegeneration remain unknown, but analyses of TSE-infected brain homogenates and preparations enriched for abnormal prion protein suggest that reduced levels of copper and increased levels of manganese are associated with disease. The objectives of this study were to: (1) assess copper and manganese levels in healthy and TSE-infected Syrian hamster brain homogenates; (2) determine if the distribution of these metals can be mapped in TSE-infected brain tissue using X-ray photoelectron emission microscopy (X-PEEM) with synchrotron radiation; and (3) use X-PEEM to assess the relative amounts of copper and manganese in prion plaques in situ. In agreement with studies of other TSEs and species, we found reduced brain levels of copper and increased levels of manganese associated with disease in our hamster model. We also found that the in situ levels of these metals in brainstem were sufficient to image by X-PEEM. Using immunolabeled prion plaques in directly adjacent tissue sections to identify regions to image by X-PEEM, we found a statistically significant relationship of copper-manganese dysregulation in prion plaques: copper was depleted whereas manganese was enriched. These data provide evidence for prion plaques altering local transition metal distribution in the TSE-infected central nervous system.

  8. Effect of LIPUS on inflammatory factors, cell apoptosis and integrin signaling pathway in osteoarthritis animal models

    Directory of Open Access Journals (Sweden)

    Li-Cai Zhang

    2017-05-01

    Full Text Available Objective: To study the effect of low-intensity pulsed ultrasound (LIPUS on inflammatory factors, cell apoptosis and integrin signaling pathway in osteoarthritis animal models. Methods: Male New Zealand white rabbits were selected as the experimental animals and randomly divided into sham group, osteoarthritis model group (OA group and LIPUS intervention group (LIPUS group, animal models with osteoarthritis in hind limb knee joint were established and then given LIPUS intervention. 6 weeks after the intervention, the articular cartilage was separated to detect the expression of inflammatory factors, cell apoptosis molecules and integrin signaling pathway molecules. Results: OPN, NO, IL-1β, TNF-α, Fas, FasL, LC3-II, Beclin-1, Integrinβ1, FAK, ERK1/2, JNK, p38MAPK, MMP-1 and MMP-3 protein expression in articular cartilage of OA group were significantly higher than those of Sham group while Col-I and Col-II protein expression were significantly lower than those of Sham group; OPN, NO, IL-1β, TNF-α, Fas, FasL, LC3-II, Beclin-1, Integrinβ1, FAK, ERK1/2, JNK, p38MAPK, MMP-1 and MMP-3 protein expression in articular cartilage of LIPUS group were significantly lower than those of OA group while Col-I and Col-II protein expression were significantly higher than those of OA group. Conclusion: LIPUS has inhibiting effect on the inflammation, apoptosis and integrin signaling pathway in articular cartilage of osteoarthritis animal models, and it can promote the repair of articular cartilage.

  9. Effect of feeding different dietary protein levels on reproductive ...

    African Journals Online (AJOL)

    A feeding trial was conducted to evaluate effects of feeding different dietary protein levels on reproductive biology of African mud catfish under hapa system. Catfish fingerlings (mean body weight (4.50± 0.01g) and total length (8.0±0.2cm) were randomly stocked at 20 fish per hapa (1m3). Five experimental diets with crude ...

  10. 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.

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

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    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

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

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    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. 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.

  14. C-reactive protein levels in patients with aggressive periodontitis.

    Science.gov (United States)

    Salzberg, Trang N; Overstreet, Benjamin T; Rogers, Jeffrey D; Califano, Joseph V; Best, Al M; Schenkein, Harvey A

    2006-06-01

    Sera from patients with periodontal infections contain elevated levels of C-reactive protein (CRP) compared to periodontally healthy individuals. Most studies to date have included patients with chronic periodontitis, and few investigators have studied CRP levels in subjects with aggressive periodontitis (AgP). The purpose of this study was to determine the relative levels of serum CRP in AgP patients and periodontally healthy subjects and to examine patients' characteristics that might account for intergroup differences. Serum samples were collected from 93 patients with generalized AgP (GAgP), from 97 patients with localized AgP (LAgP), and from 91 healthy controls (non-periodontitis [NP]). Periodontal examination consisted of plaque index, gingival index, probing depth, bleeding index, and attachment loss measurements. Current smoking was assessed by determination of serum cotinine levels by enzyme-linked immunosorbent assay (ELISA), and serum CRP levels were determined using a high-sensitivity ELISA assay. The three groups were significantly different from one another (P periodontal and demographic variables and current smoking, both mean probing depth and periodontal diagnosis remained correlated with CRP levels. Patients with AgP have statistically significant elevations in serum CRP levels compared to subjects without periodontitis. Elevated CRP in these subjects might represent a contribution of periodontal infections to systemic inflammation in relatively young individuals.

  15. Combined protein- and nucleic acid-level effects of rs1143679 (R77H), a lupus-predisposing variant within ITGAM.

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    Maiti, Amit K; Kim-Howard, Xana; Motghare, Prasenjeet; Pradhan, Vandana; Chua, Kek Heng; Sun, Celi; Arango-Guerrero, María Teresa; Ghosh, Kanjaksha; Niewold, Timothy B; Harley, John B; Anaya, Juan-Manual; Looger, Loren L; Nath, Swapan K

    2014-08-01

    Integrin alpha M (ITGAM; CD11b) is a component of the macrophage-1 antigen complex, which mediates leukocyte adhesion, migration and phagocytosis as part of the immune system. We previously identified a missense polymorphism, rs1143679 (R77H), strongly associated with systemic lupus erythematosus (SLE). However, the molecular mechanisms of this variant are incompletely understood. A meta-analysis of published and novel data on 28 439 individuals with European, African, Hispanic and Asian ancestries reinforces genetic association between rs1143679 and SLE [Pmeta = 3.60 × 10(-90), odds ratio (OR) = 1.76]. Since rs1143679 is in the most active region of chromatin regulation and transcription factor binding in ITGAM, we quantitated ITGAM RNA and surface protein levels in monocytes from patients with each rs1143679 genotype. We observed that transcript levels significantly decreased for the risk allele ('A') relative to the non-risk allele ('G'), in a dose-dependent fashion: ('AA' levels in patients' monocytes were directly correlated with RNA levels. Strikingly, heterozygous individuals express much lower (average 10- to 15-fold reduction) amounts of the 'A' transcript than 'G' transcript. We found that the non-risk sequence surrounding rs1143679 exhibits transcriptional enhancer activity in vivo and binds to Ku70/80, NFKB1 and EBF1 in vitro, functions that are significantly reduced with the risk allele. Mutant CD11b protein shows significantly reduced binding to fibrinogen and vitronectin, relative to non-risk, both in purified protein and in cellular models. This two-pronged contribution (nucleic acid- and protein-level) of the rs1143679 risk allele to decreasing ITGAM activity provides insight into the molecular mechanisms of its potent association with SLE. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  16. Muscle-specific integrins in masseter muscle fibers of chimpanzees: an immunohistochemical study.

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    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

  17. C-Reactive Protein Levels in the Brugada Syndrome

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    Aimé Bonny

    2011-01-01

    Full Text Available Background. Inflammation in the Brugada syndrome (BrS and its clinical implication have been little studied. Aims. To assess the level of inflammation in BrS patients. Methods. All studied BrS patients underwent blood samples drawn for C-reactive protein (CRP levels at admission, prior to any invasive intervention. Patients with a previous ICD placement were controlled to exclude those with a recent (<14 days shock. We divided subjects into symptomatic (syncope or aborted sudden death and asymptomatic groups. In a multivariable analysis, we adjusted for significant variables (age, CRP ≥ 2 mg/L. Results. Fifty-four subjects were studied (mean age 45 ± 13 years, 49 (91% male. Twenty (37% were symptomatic. Baseline characteristics were similar in both groups. Mean CRP level was 1,4 ± 0,9 mg/L in asymptomatic and 2,4 ± 1,4 mg/L in symptomatic groups (P = .003. In the multivariate model, CRP concentrations ≥ 2 mg/L remained an independent marker for being symptomatic (P = .018; 95% CI: 1.3 to 19.3. Conclusion. Inflammation seems to be more active in symptomatic BrS. C-reactive protein concentrations ≥ 2 mg/L might be associated with the previous symptoms in BrS. The value of inflammation as a risk factor of arrhythmic events in BrS needs to be studied.

  18. Levels of acute phase proteins remain stable after ischemic stroke

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    Paik Myunghee C

    2006-10-01

    Full Text Available Abstract Background Inflammation and inflammatory biomarkers play an important role in atherosclerosis and cardiovascular disease. Little information is available, however, on time course of serum markers of inflammation after stroke. Methods First ischemic stroke patients ≥40 years old had levels of high-sensitivity C-reactive protein (hsCRP, serum amyloid A (SAA, and fibrinogen measured in plasma samples drawn at 1, 2, 3, 7, 14, 21 and 28 days after stroke. Levels were log-transformed as needed, and parametric and non-parametric statistical tests were used to test for evidence of a trend in levels over time. Levels of hsCRP and SAA were also compared with levels in a comparable population of stroke-free participants. Results Mean age of participants with repeated measures (n = 21 was 65.6 ± 11.6 years, and 13 (61.9% were men, and 15 (71.4% were Hispanic. Approximately 75% of patients (n = 15 had mild strokes (NIH Stroke Scale score 0–5. There was no evidence of a time trend in levels of hsCRP, SAA, or fibrinogen for any of the markers during the 28 days of follow-up. Mean log(hsCRP was 1.67 ± 1.07 mg/L (median hsCRP 6.48 mg/L among stroke participants and 1.00 ± 1.18 mg/L (median 2.82 mg/L in a group of 1176 randomly selected stroke-free participants from the same community (p = 0.0252. Conclusion Levels of hsCRP are higher in stroke patients than in stroke-free subjects. Levels of inflammatory biomarkers associated with atherosclerosis, including hsCRP, appear to be stable for at least 28 days after first ischemic stroke.

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

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    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

  20. Effect of Crude Protein Levels in Concentrate and Concentrate Levels in Diet on Fermentation

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    Dinh Van Dung

    2014-06-01

    Full Text Available The effect of concentrate mixtures with crude protein (CP levels 10%, 13%, 16%, and 19% and diets with roughage to concentrate ratios 80:20, 60:40, 40:60, and 20:80 (w/w were determined on dry matter (DM and organic matter (OM digestibility, and fermentation metabolites using an in vitro fermentation technique. In vitro fermented attributes were measured after 4, 24, and 48 h of incubation respectively. The digestibility of DM and OM, and total volatile fatty acid (VFA increased whereas pH decreased with the increased amount of concentrate in the diet (p<0.001, however CP levels of concentrate did not have any influence on these attributes. Gas production reduced with increased CP levels, while it increased with increasing concentrate levels. Ammonia nitrogen (NH3-N concentration and microbial CP production increased significantly (p<0.05 by increasing CP levels and with increasing concentrate levels in diet as well, however, no significant difference was found between 16% and 19% CP levels. Therefore, 16% CP in concentrate and increasing proportion of concentrate up to 80% in diet all had improved digestibility of DM and organic matter, and higher microbial protein production, with improved fermentation characteristics.

  1. β1 integrin signaling promotes neuronal migration along vascular scaffolds in the post-stroke brain

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    Teppei Fujioka

    2017-02-01

    Full Text Available Cerebral ischemic stroke is a main cause of chronic disability. However, there is currently no effective treatment to promote recovery from stroke-induced neurological symptoms. Recent studies suggest that after stroke, immature neurons, referred to as neuroblasts, generated in a neurogenic niche, the ventricular-subventricular zone, migrate toward the injured area, where they differentiate into mature neurons. Interventions that increase the number of neuroblasts distributed at and around the lesion facilitate neuronal repair in rodent models for ischemic stroke, suggesting that promoting neuroblast migration in the post-stroke brain could improve efficient neuronal regeneration. To move toward the lesion, neuroblasts form chain-like aggregates and migrate along blood vessels, which are thought to increase their migration efficiency. However, the molecular mechanisms regulating these migration processes are largely unknown. Here we studied the role of β1-class integrins, transmembrane receptors for extracellular matrix proteins, in these migrating neuroblasts. We found that the neuroblast chain formation and blood vessel-guided migration critically depend on β1 integrin signaling. β1 integrin facilitated the adhesion of neuroblasts to laminin and the efficient translocation of their soma during migration. Moreover, artificial laminin-containing scaffolds promoted neuroblast chain formation and migration toward the injured area. These data suggest that laminin signaling via β1 integrin supports vasculature-guided neuronal migration to efficiently supply neuroblasts to injured areas. This study also highlights the importance of vascular scaffolds for cell migration in development and regeneration.

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

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    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

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

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    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

  4. Integrin-linked kinase is involved in matrix-induced hepatocyte differentiation

    International Nuclear Information System (INIS)

    Gkretsi, Vasiliki; Bowen, William C.; Yang, Yu; Wu, Chuanyue; Michalopoulos, George K.

    2007-01-01

    Hepatocytes have restricted proliferative capacity in culture and when cultured without matrix, lose the hepatocyte-specific gene expression and characteristic cellular micro-architecture. Overlay of matrix-preparations on de-differentiated hepatocytes restores differentiation. Integrin-linked kinase (ILK) is a cell-matrix-adhesion protein crucial in fundamental processes such as differentiation and survival. In this study, we investigated the role of ILK, and its binding partners PINCH, α-parvin, and Mig-2 in matrix-induced hepatocyte differentiation. We report here that ILK is present in the liver and localizes at cell-matrix adhesions of cultured hepatocytes. We also show that ILK, PINCH, α-parvin, and Mig-2 expression level is dramatically reduced in the re-differentiated hepatocytes. Interestingly, hepatocytes lacking ILK undergo matrix-induced differentiation but their differentiation is incomplete, as judged by monitoring cell morphology and production of albumin. Our results show that ILK and cell-matrix adhesion proteins play an important role in the process of matrix-induced hepatocyte differentiation

  5. Honey bee protein atlas at organ-level resolution.

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    Chan, Queenie W T; Chan, Man Yi; Logan, Michelle; Fang, Yuan; Higo, Heather; Foster, Leonard J

    2013-11-01

    Genome sequencing has provided us with gene lists but cannot tell us where and how their encoded products work together to support life. Complex organisms rely on differential expression of subsets of genes/proteins in organs and tissues, and, in concert, evolved to their present state as they function together to improve an organism's overall reproductive fitness. Proteomics studies of individual organs help us understand their basic functions, but this reductionist approach misses the larger context of the whole organism. This problem could be circumvented if all the organs in an organism were comprehensively studied by the same methodology and analyzed together. Using honey bees (Apis mellifera L.) as a model system, we report here an initial whole proteome of a complex organism, measuring 29 different organ/tissue types among the three honey bee castes: queen, drone, and worker. The data reveal that, e.g., workers have a heightened capacity to deal with environmental toxins and queens have a far more robust pheromone detection system than their nestmates. The data also suggest that workers altruistically sacrifice not only their own reproductive capacity but also their immune potential in favor of their queen. Finally, organ-level resolution of protein expression offers a systematic insight into how organs may have developed.

  6. Serum transferrin levels in children with protein-energy malnutrition

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    Selime Aydoğdu

    2013-03-01

    Full Text Available Objective: Although the diagnosis of patients with severemalnutrition is easy, it is very difficult to recognize patientswith mild and moderate malnutrition. A variety of methodsattempts to develop for early diagnosis of these cases.In this study, we evaluated the serum transferrin and albuminlevels in children with mild, moderate and severeprotein-energy malnutrition (PEM.Materials and methods: Children admitted to our policlinic,aged between 3 and 25 months, 45 subjects withPEM and 39 healthy subjects (control group were evaluated.According to the Gomez, Waterlow and Kanawatisubjects with PEM were divided in 3 subgroups mild,moderate and severe PEM. Anthropometric measurementsand biochemical results of 4 groups were compared.Results: For albumin levels in mild to moderate PEMgroups, 37.7% sensitivity, and 28.5% specificity, positivepredictive value 54%; negative predictive value 16.6%was found. For severe PEM sensitivity, specificity, positivepredictive value and negative predictive value were71%, 62.5%, 45%, and 83.3% respectively.With respect to the levels of transferrin, a significant differencewas found between mild PEM-control and moderatePEM-control groups (p0.05.Conclusion: Our study results showed that albumin isa weak indicator in mild-moderate PEM. In these cases,serum transferrin level reduces before decreasing of albuminlevel, thus it may be an early sensitive finding thatcan be used as a sensitive parameter in the diagnosis ofearly stages of malnutrition.Key words: Protein energy malnutrition, children, albumin,transferrin

  7. 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

  8. Regulation of α5 and αV Integrin Expression by GDF-5 and BMP-7 in Chondrocyte Differentiation and Osteoarthritis.

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    David Garciadiego-Cázares

    Full Text Available The Integrin β1 family is the major receptors of the Extracellular matrix (ECM, and the synthesis and degradation balance of ECM is seriously disrupted during Osteoarthritis (OA. In this scenario, integrins modify their pattern expression and regulate chondrocyte differentiation in the articular cartilage. Members of the Transforming growth factor beta (Tgf-β Superfamily, such as Growth differentiation factor 5 (Gdf-5 and Bone morphogenetic protein 7 (Bmp-7, play a key role in joint formation and could regulate the integrin expression during chondrocyte differentiation and osteoarthritis progression in an experimental OA rat model. Decrease of α5 integrin expression in articular cartilage was related with chondrocyte dedifferentiation during OA progression, while increase of α1, α2, and α3 integrin expression was related with fibrous areas in articular cartilage during OA. Hypertrophic chondrocytes expressed αV integrin and was increased in the articular cartilage of rats with OA. Integrin expression during chondrocyte differentiation was also analyzed in a micromass culture system of mouse embryo mesenchymal cells, micromass cultures was treated with Gdf-5 or Bmp-7 for 4 and 6 days, respectively. Gdf-5 induced the expression of the α5 sub-unit, while Bmp-7 induced the expression of the αV sub-unit. This suggests a switch in signaling for prehypertrophic chondrocyte differentiation towards hypertrophy, where Gdf-5 could maintain the articular chondrocyte phenotype and Bmp-7 would induce hypertrophy. Decrease of Ihh expression during late stages of OA in rat model suggest that the ossification in OA rat knees and endochondral ossification could be activated by Bmp-7 and αV integrin in absence of Ihh. Thus, chondrocyte phenotype in articular cartilage is similar to prehypetrophic chondrocyte in growth plate, and is preserved due to the presence of Indian hedgehog (Ihh, Gdf-5 and α5 integrin to maintain articular cartilage and prevent

  9. Modulation of C. elegans Touch Sensitivity Is Integrated at Multiple Levels

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    Chen, Xiaoyin

    2014-01-01

    Sensory systems can adapt to different environmental signals. Here we identify four conditions that modulate anterior touch sensitivity in Caenorhabditis elegans after several hours and demonstrate that such sensory modulation is integrated at multiple levels to produce a single output. Prolonged vibration involving integrin signaling directly sensitizes the touch receptor neurons (TRNs). In contrast, hypoxia, the dauer state, and high salt reduce touch sensitivity by preventing the release of long-range neuroregulators, including two insulin-like proteins. Integration of these latter inputs occurs at upstream neurohormonal cells and at the insulin signaling cascade within the TRNs. These signals and those from integrin signaling converge to modulate touch sensitivity by regulating AKT kinases and DAF-16/FOXO. Thus, activation of either the integrin or insulin pathways can compensate for defects in the other pathway. This modulatory system integrates conflicting signals from different modalities, and adapts touch sensitivity to both mechanical and non-mechanical conditions. PMID:24806678

  10. 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.

  11. Alpha-v Integrin Targeted PET Imaging of Breast Cancer Angiogenesis and Low-Dose Metronomic Anti-Angiogenic Chemotherapy Efficacy

    National Research Council Canada - National Science Library

    Chen, Xiaoyuan

    2006-01-01

    ...) To demonstrate the feasibility of PET/18F-RGD to image breast tumor growth spread and angiogenesis as well as quantifying alpha-v integrin expression level during breast tumor neovascularization over time. (3...

  12. Alpha-v Integrin Targeted PET Imaging of Breast Cancer Angiogenesis and Low-Dose Metronomic Anti-Angiogenic Chemotherapy Efficacy

    National Research Council Canada - National Science Library

    Chen, Xiaoyuan

    2007-01-01

    ...) To demonstrate the feasibility of PET/18F-RGD to image breast tumor growth spread and angiogenesis as well as quantifying alpha v-integrin expression level during breast tumor neovascularization over time. (3...

  13. Alpha-V Integrin Targeted PET Imagining of Breast Cancer Angiogenesis and Lose-Dose Metronomic Anti-Angiogenic Chemotherapy Efficacy

    National Research Council Canada - National Science Library

    Chen, Xiaoyuan

    2005-01-01

    ...) To demonstrate the feasibility of PET/18F-RGD to image breast tumor growth, spread, and angiogenesis as well as quantifying av-integrin expression level during breast tumor neovascularization overtime. (3...

  14. the effect of dietary energy and protein levels on the composition

    African Journals Online (AJOL)

    Zannel

    Keywords: Breeding ostriches, nutrition, energy, protein, amino acids, egg ... Yolk is an important nutritional component of the avian egg because .... 3 (energy) x 3 (protein) factorial design with energy and protein levels featuring as main factors. ... No significant interactions were observed between energy and protein levels.

  15. 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.

  16. 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

  17. 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

  18. Integrin expression by human osteoblasts cultured on degradable polymeric materials applicable for tissue engineered bone.

    Science.gov (United States)

    El-Amin, Saadiq F; Attawia, Mohamed; Lu, Helen H; Shah, Asist K; Chang, Richard; Hickok, Noreen J; Tuan, Rocky S; Laurencin, Cato T

    2002-01-01

    The use of biodegradable polymers in the field of orthopaedic surgery has gained increased popularity, as surgical pins and screws, and as potential biological scaffolds for repairing cartilage and bone defects. One such group of polymers that has gained considerable attention are the polyesters, poly(lactide-co-glycolide) (PLAGA) and polylactic acid (PLA), because of their minimal tissue inflammatory response, favorable biocompatibility and degradation characteristics. The objective of this study was to evaluate human osteoblastic cell adherence and growth on PLAGA and PLA scaffolds by examining integrin receptor (alpha2, alpha3, alpha4, alpha5, alpha6 and beta1) expression. Primary human osteoblastic cells isolated from trabecular bone adhered efficiently to both PLAGA and PLA, with the rate of adherence on PLAGA comparable to that of control tissue culture polystyrene (TCPS), and significantly higher than on PLA polymers at 3, 6 and 12 h. Human osteoblastic phenotypic expression, alkaline phosphatase (ALP) activity was positive on both degradable matrices, whereas osteocalcin levels were significantly higher on cells grown on PLAGA than on PLA composites. Interestingly, the integrin subunits, alpha2, alpha3, alpha4, alpha5, alpha6 and beta1 were all expressed at higher levels by osteoblasts cultured on PLAGA than those on PLA as analyzed by westerns blots and by flow cytometry. Among the integrins, alpha2, beta5 and beta1 showed the greatest difference in levels between the two surfaces. Thus, both PLA and PLAGA support osteoblastic adhesion and its accompanying engagement of integrin receptor and expression of osteocalcin and ALP. However PLAGA consistently appeared to be a better substrate for osteoblastic cells based on these parameters. This study is one of the first to investigate the ability of primary human osteoblastic cells isolated from trabecular bone to adhere to the biodegradable polymers PLAGA and PLA, and to examine the expression of their key

  19. Distribution of alpha3, alpha5 and alpha(v) integrin subunits in mature and immature human oocytes.

    Science.gov (United States)

    Capmany, G; Mart, M; Santaló, J; Bolton, V N

    1998-10-01

    The distribution of three integrin subunits, alpha3, alpha5 and alpha(v), in immature and mature human oocytes has been examined using immunofluorescence and confocal microscopy. The results demonstrate that both alpha5 and alpha(v) are present at the germinal vesicle stage, while alpha3 was only detected in oocytes after germinal vesicle breakdown, in metaphase I and II stage oocytes. The cortical concentration of integrin subunits alpha3 and alpha5 is consistent with their localization in the oolemma. In contrast, the homogeneous distribution of alpha(v) throughout the oocyte suggests the existence of cytoplasmic reservoirs of this protein in the oocyte.

  20. 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.

  1. 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.

  2. 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

  3. 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.

  4. 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.

  5. 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...

  6. 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.

  7. Role of β1 integrins and bacterial adhesins for Yop injection into leukocytes in Yersinia enterocolitica systemic mouse infection.

    Science.gov (United States)

    Deuschle, Eva; Keller, Birgit; Siegfried, Alexandra; Manncke, Birgit; Spaeth, Tanja; Köberle, Martin; Drechsler-Hake, Doreen; Reber, Julia; Böttcher, Ralph T; Autenrieth, Stella E; Autenrieth, Ingo B; Bohn, Erwin; Schütz, Monika

    2016-02-01

    Injection of Yersinia outer proteins (Yops) into host cells by a type III secretion system is an important immune evasion mechanism of Yersinia enterocolitica (Ye). In this process Ye invasin (Inv) binds directly while Yersinia adhesin A (YadA) binds indirectly via extracellular matrix (ECM) proteins to β1 integrins on host cells. Although leukocytes turned out to be an important target of Yop injection by Ye, it was unclear which Ye adhesins and which leukocyte receptors are required for Yop injection. To explain this, we investigated the role of YadA, Inv and β1 integrins for Yop injection into leukocytes and their impact on the course of systemic Ye infection in mice. Ex vivo infection experiments revealed that adhesion of Ye via Inv or YadA is sufficient to promote Yop injection into leukocytes as revealed by a β-lactamase reporter assay. Serum factors inhibit YadA- but not Inv-mediated Yop injection into B and T cells, shifting YadA-mediated Yop injection in the direction of neutrophils and other myeloid cells. Systemic Ye mouse infection experiments demonstrated that YadA is essential for Ye virulence and Yop injection into leukocytes, while Inv is dispensable for virulence and plays only a transient and minor role for Yop injection in the early phase of infection. Ye infection of mice with β1 integrin-depleted leukocytes demonstrated that β1 integrins are dispensable for YadA-mediated Yop injection into leukocytes, but contribute to Inv-mediated Yop injection. Despite reduced Yop injection into leukocytes, β1 integrin-deficient mice exhibited an increased susceptibility for Ye infection, suggesting an important role of β1 integrins in immune defense against Ye. This study demonstrates that Yop injection into leukocytes by Ye is largely mediated by YadA exploiting, as yet unknown, leukocyte receptors. Copyright © 2015. Published by Elsevier GmbH.

  8. F-box only protein 2 (Fbxo2) regulates amyloid precursor protein levels and processing.

    Science.gov (United States)

    Atkin, Graham; Hunt, Jack; Minakawa, Eiko; Sharkey, Lisa; Tipper, Nathan; Tennant, William; Paulson, Henry L

    2014-03-07

    The amyloid precursor protein (APP) is an integral membrane glycoprotein whose cleavage products, particularly amyloid-β, accumulate in Alzheimer disease (AD). APP is present at synapses and is thought to play a role in both the formation and plasticity of these critical neuronal structures. Despite the central role suggested for APP in AD pathogenesis, the mechanisms regulating APP in neurons and its processing into cleavage products remain incompletely understood. F-box only protein 2 (Fbxo2), a neuron-enriched ubiquitin ligase substrate adaptor that preferentially binds high-mannose glycans on glycoproteins, was previously implicated in APP processing by facilitating the degradation of the APP-cleaving β-secretase, β-site APP-cleaving enzyme. Here, we sought to determine whether Fbxo2 plays a similar role for other glycoproteins in the amyloid processing pathway. We present in vitro and in vivo evidence that APP is itself a substrate for Fbxo2. APP levels were decreased in the presence of Fbxo2 in non-neuronal cells, and increased in both cultured hippocampal neurons and brain tissue from Fbxo2 knock-out mice. The processing of APP into its cleavage products was also increased in hippocampi and cultured hippocampal neurons lacking Fbxo2. In hippocampal slices, this increase in cleavage products was accompanied by a significant reduction in APP at the cell surface. Taken together, these results suggest that Fbxo2 regulates APP levels and processing in the brain and may play a role in modulating AD pathogenesis.

  9. Gene-specific correlation of RNA and protein levels in human cells and tissues

    DEFF Research Database (Denmark)

    Edfors, Fredrik; Danielsson, Frida; Hallström, Björn M.

    2016-01-01

    An important issue for molecular biology is to establish whether transcript levels of a given gene can be used as proxies for the corresponding protein levels. Here, we have developed a targeted proteomics approach for a set of human non-secreted proteins based on parallel reaction monitoring...... to measure, at steady-state conditions, absolute protein copy numbers across human tissues and cell lines and compared these levels with the corresponding mRNA levels using transcriptomics. The study shows that the transcript and protein levels do not correlate well unless a gene-specific RNA-to-protein (RTP...

  10. 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.

  11. Investigation of integrin expression on the surface of osteoblast-like cells by atomic force microscopy

    International Nuclear Information System (INIS)

    Caneva Soumetz, Federico; Saenz, Jose F.; Pastorino, Laura; Ruggiero, Carmelina; Nosi, Daniele; Raiteri, Roberto

    2010-01-01

    The transforming growth factor β1 (TGF-β1) is a human cytokine which has been demonstrated to modulate cell surface integrin repertoire. In this work integrin expression in response to TGF-β1 stimulation has been investigated on the surface of human osteoblast-like cells. We used atomic force microscopy (AFM) and confocal laser scanning microscopy to assess integrin expression and to evaluate their distribution over the dorsal side of the plasma membrane. AFM probes have been covalently functionalised with monoclonal antibodies specific to the β1 integrin subunit. Force curves have been collected in order to obtain maps of the interaction between the immobilized antibody and the respective cell membrane receptors. Adhesion peaks have been automatically detected by means of an ad hoc developed data analysis software. The specificity of the detected interactions has been assessed by adding free antibody in the solution and monitoring the dramatic decrease in the recorded interactions. In addition, the effect of TGF-β1 treatment on both the fluorescence signal and the adhesion events has been tested. The level of expression of the β1 integrin subunit was enhanced by TGF-β1. As a further analysis, the adhesion force of the single living cells to the substrate was measured by laterally pushing the cell with the AFM tip and measuring the force necessary to displace it. The treatment with TGF-β1 resulted in a decrease of the cell/substrate adhesion force. Results obtained by AFM have been validated by confocal laser scanning microscopy thus demonstrating the high potential of the AFM technique for the investigation of cell surface receptors distribution and trafficking at the nanoscale.

  12. Investigation of integrin expression on the surface of osteoblast-like cells by atomic force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Caneva Soumetz, Federico [Department of Communication, Computer and System Sciences, University of Genova, Via Opera Pia, 13-16145 Genova (Italy); Saenz, Jose F. [Biophysical and Electronic Engineering Department, University of Genova, Via All' Opera Pia 11a, 16145 Genova (Italy); Pastorino, Laura; Ruggiero, Carmelina [Department of Communication, Computer and System Sciences, University of Genova, Via Opera Pia, 13-16145 Genova (Italy); Nosi, Daniele [Department of Anatomy, Histology and Forensic Medicine, Bio-photonic Laboratory, University of Florence, viale Morgagni, 85 Firenze, CAP 50134 Florence (Italy); Raiteri, Roberto, E-mail: rr@unige.it [Biophysical and Electronic Engineering Department, University of Genova, Via All' Opera Pia 11a, 16145 Genova (Italy)

    2010-03-15

    The transforming growth factor {beta}1 (TGF-{beta}1) is a human cytokine which has been demonstrated to modulate cell surface integrin repertoire. In this work integrin expression in response to TGF-{beta}1 stimulation has been investigated on the surface of human osteoblast-like cells. We used atomic force microscopy (AFM) and confocal laser scanning microscopy to assess integrin expression and to evaluate their distribution over the dorsal side of the plasma membrane. AFM probes have been covalently functionalised with monoclonal antibodies specific to the {beta}1 integrin subunit. Force curves have been collected in order to obtain maps of the interaction between the immobilized antibody and the respective cell membrane receptors. Adhesion peaks have been automatically detected by means of an ad hoc developed data analysis software. The specificity of the detected interactions has been assessed by adding free antibody in the solution and monitoring the dramatic decrease in the recorded interactions. In addition, the effect of TGF-{beta}1 treatment on both the fluorescence signal and the adhesion events has been tested. The level of expression of the {beta}1 integrin subunit was enhanced by TGF-{beta}1. As a further analysis, the adhesion force of the single living cells to the substrate was measured by laterally pushing the cell with the AFM tip and measuring the force necessary to displace it. The treatment with TGF-{beta}1 resulted in a decrease of the cell/substrate adhesion force. Results obtained by AFM have been validated by confocal laser scanning microscopy thus demonstrating the high potential of the AFM technique for the investigation of cell surface receptors distribution and trafficking at the nanoscale.

  13. 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...

  14. 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...

  15. Profiling of Human Molecular Pathways Affected by Retrotransposons at the Level of Regulation by Transcription Factor Proteins

    Science.gov (United States)

    Nikitin, Daniil; Penzar, Dmitry; Garazha, Andrew; Sorokin, Maxim; Tkachev, Victor; Borisov, Nicolas; Poltorak, Alexander; Prassolov, Vladimir; Buzdin, Anton A.

    2018-01-01

    Endogenous retroviruses and retrotransposons also termed retroelements (REs) are mobile genetic elements that were active until recently in human genome evolution. REs regulate gene expression by actively reshaping chromatin structure or by directly providing transcription factor binding sites (TFBSs). We aimed to identify molecular processes most deeply impacted by the REs in human cells at the level of TFBS regulation. By using ENCODE data, we identified ~2 million TFBS overlapping with putatively regulation-competent human REs located in 5-kb gene promoter neighborhood (~17% of all TFBS in promoter neighborhoods; ~9% of all RE-linked TFBS). Most of REs hosting TFBS were highly diverged repeats, and for the evolutionary young (0–8% diverged) elements we identified only ~7% of all RE-linked TFBS. The gene-specific distributions of RE-linked TFBS generally correlated with the distributions for all TFBS. However, several groups of molecular processes were highly enriched in the RE-linked TFBS regulation. They were strongly connected with the immunity and response to pathogens, with the negative regulation of gene transcription, ubiquitination, and protein degradation, extracellular matrix organization, regulation of STAT signaling, fatty acids metabolism, regulation of GTPase activity, protein targeting to Golgi, regulation of cell division and differentiation, development and functioning of perception organs and reproductive system. By contrast, the processes most weakly affected by the REs were linked with the conservative aspects of embryo development. We also identified differences in the regulation features by the younger and older fractions of the REs. The regulation by the older fraction of the REs was linked mainly with the immunity, cell adhesion, cAMP, IGF1R, Notch, Wnt, and integrin signaling, neuronal development, chondroitin sulfate and heparin metabolism, and endocytosis. The younger REs regulate other aspects of immunity, cell cycle progression and

  16. Profiling of Human Molecular Pathways Affected by Retrotransposons at the Level of Regulation by Transcription Factor Proteins

    Directory of Open Access Journals (Sweden)

    Daniil Nikitin

    2018-01-01

    Full Text Available Endogenous retroviruses and retrotransposons also termed retroelements (REs are mobile genetic elements that were active until recently in human genome evolution. REs regulate gene expression by actively reshaping chromatin structure or by directly providing transcription factor binding sites (TFBSs. We aimed to identify molecular processes most deeply impacted by the REs in human cells at the level of TFBS regulation. By using ENCODE data, we identified ~2 million TFBS overlapping with putatively regulation-competent human REs located in 5-kb gene promoter neighborhood (~17% of all TFBS in promoter neighborhoods; ~9% of all RE-linked TFBS. Most of REs hosting TFBS were highly diverged repeats, and for the evolutionary young (0–8% diverged elements we identified only ~7% of all RE-linked TFBS. The gene-specific distributions of RE-linked TFBS generally correlated with the distributions for all TFBS. However, several groups of molecular processes were highly enriched in the RE-linked TFBS regulation. They were strongly connected with the immunity and response to pathogens, with the negative regulation of gene transcription, ubiquitination, and protein degradation, extracellular matrix organization, regulation of STAT signaling, fatty acids metabolism, regulation of GTPase activity, protein targeting to Golgi, regulation of cell division and differentiation, development and functioning of perception organs and reproductive system. By contrast, the processes most weakly affected by the REs were linked with the conservative aspects of embryo development. We also identified differences in the regulation features by the younger and older fractions of the REs. The regulation by the older fraction of the REs was linked mainly with the immunity, cell adhesion, cAMP, IGF1R, Notch, Wnt, and integrin signaling, neuronal development, chondroitin sulfate and heparin metabolism, and endocytosis. The younger REs regulate other aspects of immunity, cell cycle

  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. Interactive effect of dietary protein level and zilpaterol hydrochloride ...

    African Journals Online (AJOL)

    p2492989

    feedlot performance and meat quality of steers ... result of decreased protein degradation and increased protein synthesis (Fiems, ... sheep as well as data from some BAA trials provide evidence to associate ... The perception is that meat is now ... Table 1 Dietary treatments of steers with a mean live weight of 278 ± 20 kg ...

  19. Effect of graded levels and sources of protein on scrotal ...

    African Journals Online (AJOL)

    Iso caloric rations (10.50 MJ/kg DM ME) were formulated using non-conventional protein source (maize offal and dry layer litter) to contain 12.11% CP, 14.96% CP, and 17.94% CP and fed to groups A, B and C respectively. Another ration was formulated using conventional protein source (maize, wheat bran, groundnut ...

  20. Exploring Sequence Characteristics Related to High- Level Production of Secreted Proteins in Aspergillus niger

    NARCIS (Netherlands)

    Van den Berg, B.A.; Reinders, M.J.T.; Hulsman, M.; Wu, L.; Pel, H.J.; Roubos, J.A.; De Ridder, D.

    2012-01-01

    Protein sequence features are explored in relation to the production of over-expressed extracellular proteins by fungi. Knowledge on features influencing protein production and secretion could be employed to improve enzyme production levels in industrial bioprocesses via protein engineering. A large

  1. Cleavage of ST6Gal I by Radiation-Induced BACE1 Inhibits Golgi-Anchored ST6Gal I-Mediated Sialylation of Integrin β1 and Migration in Colon Cancer Cells

    International Nuclear Information System (INIS)

    Lee, Minyoung; Park, Jung-Jin; Ko, Young-Gyu; Lee, Yun-Sil

    2012-01-01

    Previously, we found that β-galactoside α2,6-sialyltransferase (ST6Gal I), an enzyme that adds sialic acids to N-linked oligosaccharides of glycoproteins and is frequently overexpressed in cancer cells, is up-regulated by ionizing radiation (IR) and cleaved to a form possessing catalytic activity comparable to that of the Golgi-localized enzyme. Moreover, this soluble form is secreted into the culture media. Induction of ST6Gal I significantly increased the migration of colon cancer cells via sialylation of integrin β1. Here, we further investigated the mechanisms underlying ST6Gal I cleavage, solubilization and release from cells, and addressed its functions, focusing primarily on cancer cell migration. We performed immunoblotting and lectin affinity assay to analyze the expression of ST6 Gal I and level of sialylated integrin β1. After ionizing radiation, migration of cells was measured by in vitro migration assay. α2, 6 sialylation level of cell surface was analyzed by flow cytometry. Cell culture media were concentrated and then analyzed for soluble ST6Gal I levels using an α2, 6 sialyltransferase sandwich ELISA. We found that ST6Gal I was cleaved by BACE1 (β-site amyloid precursor protein-cleaving enzyme), which was specifically overexpressed in response to IR. The soluble form of ST6Gal I, which also has sialyltransferase enzymatic activity, was cleaved from the Golgi membrane and then released into the culture media. Both non-cleaved and cleaved forms of ST6Gal I significantly increased colon cancer cell migration in a sialylation-dependent manner. The pro-migratory effect of the non-cleaved form of ST6Gal I was dependent on integrin β1 sialylation, whereas that of the cleaved form of ST6Gal I was not, suggesting that other intracellular sialylated molecules apart from cell surface molecules such as integrin β1 might be involved in mediating the pro-migratory effects of the soluble form of ST6Gal I. Moreover, production of soluble form ST6Gal I by

  2. Complementary roles of KCa3.1 channels and β1-integrin during alveolar epithelial repair.

    Science.gov (United States)

    Girault, Alban; Chebli, Jasmine; Privé, Anik; Trinh, Nguyen Thu Ngan; Maillé, Emilie; Grygorczyk, Ryszard; Brochiero, Emmanuelle

    2015-09-04

    Extensive alveolar epithelial injury and remodelling is a common feature of acute lung injury and acute respiratory distress syndrome (ARDS) and it has been established that epithelial regeneration, and secondary lung oedema resorption, is crucial for ARDS resolution. Much evidence indicates that K(+) channels are regulating epithelial repair processes; however, involvement of the KCa3.1 channels in alveolar repair has never been investigated before. Wound-healing assays demonstrated that the repair rates were increased in primary rat alveolar cell monolayers grown on a fibronectin matrix compared to non-coated supports, whereas an anti-β1-integrin antibody reduced it. KCa3.1 inhibition/silencing impaired the fibronectin-stimulated wound-healing rates, as well as cell migration and proliferation, but had no effect in the absence of coating. We then evaluated a putative relationship between KCa3.1 channel and the migratory machinery protein β1-integrin, which is activated by fibronectin. Co-immunoprecipitation and immunofluorescence experiments indicated a link between the two proteins and revealed their cellular co-distribution. In addition, we demonstrated that KCa3.1 channel and β1-integrin membrane expressions were increased on a fibronectin matrix. We also showed increased intracellular calcium concentrations as well as enhanced expression of TRPC4, a voltage-independent calcium channel belonging to the large TRP channel family, on a fibronectin matrix. Finally, wound-healing assays showed additive effects of KCa3.1 and TRPC4 inhibitors on alveolar epithelial repair. Taken together, our data demonstrate for the first time complementary roles of KCa3.1 and TRPC4 channels with extracellular matrix and β1-integrin in the regulation of alveolar repair processes.

  3. Effects of CD49d-targeted antisense-oligonucleotide on α4 integrin expression and function of acute lymphoblastic leukemia cells: Results of in vitro and in vivo studies.

    Directory of Open Access Journals (Sweden)

    Yann Duchartre

    Full Text Available We recently demonstrated the effectiveness of blocking CD49d with anti-functional antibodies or small molecule inhibitors as a rational targeted approach to the treatment of acute leukemia in combination with chemotherapy. Antisense oligonucleotide promises to be no less specific than antibodies and inhibitors, but more interesting for pharmacokinetics and pharmacodynamics. We addressed this using the published CD49d antisense drug ATL1102. In vitro, we incubated/nucleofected the ALL cell line Kasumi-2 with ATL1102. In vivo, immunodeficient hosts were engrafted with primary ALL cells and treated with ATL1102. Changes in expression of CD49d mRNA and CD49d protein, and of cooperating gene products, including ß1 integrin and CXCR4, as well as survival in the mouse experiments were quantified. We observed dose-dependent down-regulation of CD49d mRNA and protein levels and its partner integrin ß1 cell surface protein level and, up-regulation of CXCR4 surface expression. The suppression was more pronounced after nucleofection than after incubation, where down-regulation was significant only at the higher doses. In vivo effects of ATL1102 were not sufficient to translate into "clinical" benefit in the leukemia model. In summary, antisense oligonucleotides are successful tools for specifically modulating gene expression but sufficient delivery to down-regulate CD49d in vivo may be difficult to achieve.

  4. 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.

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

    Science.gov (United States)

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

    2017-12-01

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

  6. Angiopoietin-related growth factor (AGF) supports adhesion, spreading, and migration of keratinocytes, fibroblasts, and endothelial cells through interaction with RGD-binding integrins

    International Nuclear Information System (INIS)

    Zhang Yueqing; Hu Xiaobo; Tian Ruiyang; Wei Wangui; Hu Wei; Chen Xia; Han Wei; Chen Huayou; Gong Yi

    2006-01-01

    Angiopoietin-related growth factor (AGF) is a newly identified member of angiopoietin-related proteins (ARPs)/angiopoietin-like proteins (Angptls). AGF has been considered as a novel growth factor in accelerating cutaneous wound healing, as it is capable of stimulating keratinocytes proliferation as well as angiogenesis. But in our paper, we demonstrate that AGF stimulates keratinocytes proliferation only at high protein concentration, however, it can potently promote adhesion, spreading, and migration of keratinocytes, fibroblasts, and endothelial cells. Furthermore, we confirm that the adhesion and migration cellular events are mediated by RGD-binding integrins, most possibly the α v -containing integrins, by in vitro inhibition assays using synthetic competitive peptides. Our results strongly suggest that AGF is an integrin ligand as well as a mitogenic growth factor and theoretically participates in cutaneous wound healing in a more complex mechanism

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. The signaling pathway of Campylobacter jejuni-induced Cdc42 activation: Role of fibronectin, integrin beta1, tyrosine kinases and guanine exchange factor Vav2

    LENUS (Irish Health Repository)

    Krause-Gruszczynska, Malgorzata

    2011-12-28

    Abstract Background Host cell invasion by the foodborne pathogen Campylobacter jejuni is considered as one of the primary reasons of gut tissue damage, however, mechanisms and key factors involved in this process are widely unclear. It was reported that small Rho GTPases, including Cdc42, are activated and play a role during invasion, but the involved signaling cascades remained unknown. Here we utilised knockout cell lines derived from fibronectin-\\/-, integrin-beta1-\\/-, focal adhesion kinase (FAK)-\\/- and Src\\/Yes\\/Fyn-\\/- deficient mice, and wild-type control cells, to investigate C. jejuni-induced mechanisms leading to Cdc42 activation and bacterial uptake. Results Using high-resolution scanning electron microscopy, GTPase pulldowns, G-Lisa and gentamicin protection assays we found that each studied host factor is necessary for induction of Cdc42-GTP and efficient invasion. Interestingly, filopodia formation and associated membrane dynamics linked to invasion were only seen during infection of wild-type but not in knockout cells. Infection of cells stably expressing integrin-beta1 variants with well-known defects in fibronectin fibril formation or FAK signaling also exhibited severe deficiencies in Cdc42 activation and bacterial invasion. We further demonstrated that infection of wild-type cells induces increasing amounts of phosphorylated FAK and growth factor receptors (EGFR and PDGFR) during the course of infection, correlating with accumulating Cdc42-GTP levels and C. jejuni invasion over time. In studies using pharmacological inhibitors, silencing RNA (siRNA) and dominant-negative expression constructs, EGFR, PDGFR and PI3-kinase appeared to represent other crucial components upstream of Cdc42 and invasion. siRNA and the use of Vav1\\/2-\\/- knockout cells further showed that the guanine exchange factor Vav2 is required for Cdc42 activation and maximal bacterial invasion. Overexpression of certain mutant constructs indicated that Vav2 is a linker

  12. The signaling pathway of Campylobacter jejuni-induced Cdc42 activation: Role of fibronectin, integrin beta1, tyrosine kinases and guanine exchange factor Vav2

    Directory of Open Access Journals (Sweden)

    Krause-Gruszczynska Malgorzata

    2011-12-01

    Full Text Available Abstract Background Host cell invasion by the foodborne pathogen Campylobacter jejuni is considered as one of the primary reasons of gut tissue damage, however, mechanisms and key factors involved in this process are widely unclear. It was reported that small Rho GTPases, including Cdc42, are activated and play a role during invasion, but the involved signaling cascades remained unknown. Here we utilised knockout cell lines derived from fibronectin-/-, integrin-beta1-/-, focal adhesion kinase (FAK-/- and Src/Yes/Fyn-/- deficient mice, and wild-type control cells, to investigate C. jejuni-induced mechanisms leading to Cdc42 activation and bacterial uptake. Results Using high-resolution scanning electron microscopy, GTPase pulldowns, G-Lisa and gentamicin protection assays we found that each studied host factor is necessary for induction of Cdc42-GTP and efficient invasion. Interestingly, filopodia formation and associated membrane dynamics linked to invasion were only seen during infection of wild-type but not in knockout cells. Infection of cells stably expressing integrin-beta1 variants with well-known defects in fibronectin fibril formation or FAK signaling also exhibited severe deficiencies in Cdc42 activation and bacterial invasion. We further demonstrated that infection of wild-type cells induces increasing amounts of phosphorylated FAK and growth factor receptors (EGFR and PDGFR during the course of infection, correlating with accumulating Cdc42-GTP levels and C. jejuni invasion over time. In studies using pharmacological inhibitors, silencing RNA (siRNA and dominant-negative expression constructs, EGFR, PDGFR and PI3-kinase appeared to represent other crucial components upstream of Cdc42 and invasion. siRNA and the use of Vav1/2-/- knockout cells further showed that the guanine exchange factor Vav2 is required for Cdc42 activation and maximal bacterial invasion. Overexpression of certain mutant constructs indicated that Vav2 is a linker

  13. Vinculin promotes cell spreading by mechanically coupling integrins to the cytoskeleton

    Science.gov (United States)

    Ezzell, R. M.; Goldmann, W. H.; Wang, N.; Parasharama, N.; Ingber, D. E.

    1997-01-01

    Mouse F9 embryonic carcinoma 5.51 cells that lack the cytoskeletal protein vinculin spread poorly on extracellular matrix compared with wild-type F9 cells or two vinculin-transfected clones (5.51Vin3 and Vin4; Samuels et al., 1993, J. Cell Biol. 121, 909-921). In the present study, we used this model system to determine how the presence of vinculin promotes cytoskeletal alterations and associated changes in cell shape. Microscopic analysis of cell spreading at early times, revealed that 5.51 cells retained the ability to form filopodia; however, they could not form lamellipodia, assemble stress fibers, or efficiently spread over the culture substrate. Detergent (Triton X-100) studies revealed that these major differences in cell morphology and cytoskeletal organization did not result from differences in levels of total polymerized or cross-linked actin. Biochemical studies showed that 5.51 cells, in addition to lacking vinculin, exhibited slightly reduced levels of alpha-actinin and paxillin in their detergent-insoluble cytoskeleton. The absence of vinculin correlated with a decrease in the mechanical stiffness of the integrin-cytoskeleton linkage, as measured using cell magnetometry. Furthermore, when vinculin was replaced by transfection in 5.51Vin3 and 5.51Vin4 cells, the levels of cytoskeletal-associated alpha-actinin and paxillin, the efficiency of transmembrane mechanical coupling, and the formation of actin stress fibers were all restored to near wild-type levels. These findings suggest that vinculin may promote cell spreading by stabilizing focal adhesions and transferring mechanical stresses that drive cytoskeletal remodeling, rather than by altering the total level of actin polymerization or cross-linking.

  14. G protein-coupled receptor kinase 2 negatively regulates chemokine signaling at a level downstream from G protein subunits

    NARCIS (Netherlands)

    Jimenez-Sainz, MC; Murga, C; Kavelaars, A; Jurado-Pueyo, M; Krakstad, BF; Heijnen, CJ; Mayor, F; Aragay, AM

    The G protein-coupled receptor kinase 2 (GRK2) phosphorylates and desensitizes ligand-activated G protein-coupled-receptors. Here, evidence is shown for a novel role of GRK2 in regulating chemokine-mediated signals. The presence of increased levels of GRK2 in human embryonic kidney (HEK) 293 cells

  15. 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.

  16. 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

  17. An Epithelial Integrin Regulates the Amplitude of Protective Lung Interferon Responses against Multiple Respiratory Pathogens.

    Directory of Open Access Journals (Sweden)

    Victoria A Meliopoulos

    2016-08-01

    Full Text Available The healthy lung maintains a steady state of immune readiness to rapidly respond to injury from invaders. Integrins are important for setting the parameters of this resting state, particularly the epithelial-restricted αVβ6 integrin, which is upregulated during injury. Once expressed, αVβ6 moderates acute lung injury (ALI through as yet undefined molecular mechanisms. We show that the upregulation of β6 during influenza infection is involved in disease pathogenesis. β6-deficient mice (β6 KO have increased survival during influenza infection likely due to the limited viral spread into the alveolar spaces leading to reduced ALI. Although the β6 KO have morphologically normal lungs, they harbor constitutively activated lung CD11b+ alveolar macrophages (AM and elevated type I IFN signaling activity, which we traced to the loss of β6-activated transforming growth factor-β (TGF-β. Administration of exogenous TGF-β to β6 KO mice leads to reduced numbers of CD11b+ AMs, decreased type I IFN signaling activity and loss of the protective phenotype during influenza infection. Protection extended to other respiratory pathogens such as Sendai virus and bacterial pneumonia. Our studies demonstrate that the loss of one epithelial protein, αVβ6 integrin, can alter the lung microenvironment during both homeostasis and respiratory infection leading to reduced lung injury and improved survival.

  18. The molecular mechanism of mediation of adsorbed serum proteins to endothelial cells adhesion and growth on biomaterials.

    Science.gov (United States)

    Yang, Dayun; Lü, Xiaoying; Hong, Ying; Xi, Tingfei; Zhang, Deyuan

    2013-07-01

    To explore molecular mechanism of mediation of adsorbed proteins to cell adhesion and growth on biomaterials, this study examined endothelial cell adhesion, morphology and viability on bare and titanium nitride (TiN) coated nickel titanium (NiTi) alloys and chitosan film firstly, and then identified the type and amount of serum proteins adsorbed on the three surfaces by proteomic technology. Subsequently, the mediation role of the identified proteins to cell adhesion and growth was investigated with bioinformatics analyses, and further confirmed by a series of cellular and molecular biological experiments. Results showed that the type and amount of adsorbed serum proteins associated with cell adhesion and growth was obviously higher on the alloys than on the chitosan film, and these proteins mediated endothelial cell adhesion and growth on the alloys via four ways. First, proteins such as adiponectin in the adsorbed protein layer bound with cell surface receptors to generate signal transduction, which activated cell surface integrins through increasing intracellular calcium level. Another way, thrombospondin 1 in the adsorbed protein layer promoted TGF-β signaling pathway activation and enhanced integrins expression. The third, RGD sequence containing proteins such as fibronectin 1, vitronectin and thrombospondin 1 in the adsorbed protein layer bound with activated integrins to activate focal adhesion pathway, increased focal adhesion formation and actin cytoskeleton organization and mediated cell adhesion and spreading. In addition, the activated focal adhesion pathway promoted the expression of cell growth related genes and resulted in cell proliferation. The fourth route, coagulation factor II (F2) and fibronectin 1 in the adsorbed protein layer bound with cell surface F2 receptor and integrin, activated regulation of actin cytoskeleton pathway and regulated actin cytoskeleton organization. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Characterization of white shrimp Litopenaeus vannamei integrin β and its role in immunomodulation by dsRNA-mediated gene silencing.

    Science.gov (United States)

    Lin, Yong-Chin; Chen, Jiann-Chu; Chen, Yu-Yuan; Liu, Chun-Hung; Cheng, Winton; Hsu, Chih-Hung; Tsui, Wen-Ching

    2013-06-01

    The full sequence of white shrimp Litopenaeus vannamei integrin β (LV-B) is 2879bp which encodes 787 amino acids (aa) of the open reading frame (ORF). The mature protein (764 aa) contains (1) an extracellular domain (ED) of 692 aa, (2) a transmembrane domain (TD) of 23 aa, and (3) a cytoplasmic domain (CD) of 49 aa. The cloned LV-B grouped together with crayfish Pacifastacus leniusculus integrin β (PL-B1), but was far away from vertebrate integrin β1, β3, β5, β6, β7, and β8, and another L. vannamei integrin β (LV). A Southern blot analysis indicated that the cloned LV-B was a single copy of genomic DNA. LV-B mRNA was expressed in all tissues, and was highly expressed in haemocytes. LV-B was downregulated in shrimp 24 and 96h after having received white spot syndrome virus (WSSV). LV-B expression by haemocytes of shrimp was higher in the postmoult (A and B) stage, and lower in the premoult (D2/D3) stage. LV-B expression was significantly higher by shrimp reared in 2.5‰ and 5‰ salinities. Shrimp injected with integrin β dsRNA showed gene silencing of integrin β after 36h. LV-B-silenced shrimp showed decreased hyaline cells (HCs), granular cells (GCs, including semi-granular cells), the total haemocyte count (THC), respiratory bursts (RBs), and lysozyme activity, but showed increased RB/HC, superoxide dismutase (SOD) activity/HC, and the phenoloxidase (PO) activity/GC. LV-B-silenced shrimp showed upregulated expressions of lipopolysaccharide- and β-glucan-binding protein (LGBP), peroxinectin (PX), prophenoloxidase I (proPO I), proPO II, proPO-activating enzyme (ppA), α2-macroglobulin (α2-M), cytMnSOD, mtMnSOD, and heat shock protein 70 (HSP70). It was concluded that integrin β plays important roles in proPO activation, phagocytosis, and the antioxidant system for immunomodulation in shrimp. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. Zinc finger protein 521 overexpression increased transcript levels of ...

    Indian Academy of Sciences (India)

    2016-02-12

    Feb 12, 2016 ... Zinc finger protein 521 is highly expressed in brain, neural stem cells and early progenitors of the human .... Membranes were blocked for 1 h with 10% skim milk and ..... fat-like development of white fat and thermogenesis.

  1. Serum total proteins and creatinine levels in experimental gambian ...

    African Journals Online (AJOL)

    Attempt was therefore made to evaluate the effect of two strains of Trypanosoma brucei gambiense on total proteins and other serum biochemical parameters using vervet monkeys as a model. The outcome of both strains in vervet monkeys was traumatic as the monkeys died from infection 12 – 15 weeks post infection while ...

  2. Plasma protein carbonyl levels and breast cancer risk

    Czech Academy of Sciences Publication Activity Database

    Rössner ml., Pavel; Terry, M. B.; Gammon, M. D.; Agrawal, M.; Zhang, F. F.; Ferris, J.S.; Teitelbaum, S. L.; Eng, S. M.; Gaudet, M. M.; Neugut, A. I.; Santella, R. M.

    2007-01-01

    Roč. 11, č. 5 (2007), s. 1138-1148 ISSN 1582-1838 Institutional research plan: CEZ:AV0Z50390512 Keywords : oxidative stress * protein carbonyl * breast cancer Subject RIV: DN - Health Impact of the Environment Quality Impact factor: 6.807, year: 2007

  3. Serum total protein, albumin and globulin levels in Trypanosoma ...

    African Journals Online (AJOL)

    The effect of orally administered Scoparia dulcis on Trypanosoma brucei-induced changes in serum total protein, albumin and globulin were investigated in rabbits over a period of twenty eight days. Results obtained show that infection resulted in hyperproteinaemia, hyperglobulinaemia and hypoalbuminaemia. However ...

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. Blood profiling of proteins and steroids during weight maintenance with manipulation of dietary protein level and glycaemic index

    DEFF Research Database (Denmark)

    Wang, Ping; Holst, Claus; Astrup, Arne

    2012-01-01

    ) blood biomarkers of dietary protein and GI levels during the weight-maintenance phase. Blood samples were collected at baseline, after 8 weeks of low-energy diet-induced weight loss and after a 6-month dietary intervention period from female continued weight losers (n 48) and weight regainers (n 48......), evenly selected from four dietary groups that varied in protein and GI levels. The blood concentrations of twenty-nine proteins and three steroid hormones were measured. The changes in analytes during weight maintenance largely correlated negatively with the changes during weight loss, with some...

  9. 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.

  10. Synthesis and biological evaluation of potent αvβ3-integrin receptor antagonists

    International Nuclear Information System (INIS)

    Dijkgraaf, Ingrid; Kruijtzer, John A.W.; Frielink, Cathelijne; Soede, Annemieke C.; Hilbers, Hans W.; Oyen, Wim J.G.; Corstens, Frans H.M.; Liskamp, Rob M.J.; Boerman, Otto C.

    2006-01-01

    Introduction: α v β 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 α v β 3 integrin. α v β 3 Integrin, a transmembrane heterodimeric protein, binds to the arginine-glycine-aspartic acid (RGD) amino acid sequence of extracellular matrix proteins such as vitronectin and plays a pivotal role in invasion, proliferation and metastasis. Due to the selective expression of α v β 3 integrin in tumors, radiolabeled RGD peptides and peptidomimetics are attractive candidates for tumor targeting. Methods: A cyclic RGD peptide, a peptoid-peptide hybrid, an all-peptoid and a peptidomimetic compound were synthesized, conjugated with 1,4,7,10-tetraazadodecane-N,N',N'',N'''-tetraacetic acid (DOTA) and radiolabeled with 111 In. Their in vitro and in vivo α v β 3 -binding characteristics were determined. Results: IC 5 values were 236 nM for DOTA-E-c(RGDfK), 219 nM for DOTA-peptidomimetic, >10 mM for DOTA-all-peptoid and 9.25 mM for the peptoid-peptide hybrid DOTA-E-c(nRGDfK). 111 In-labeled compounds, except for [ 111 In]DOTA-all-peptoid, showed specific uptake in human α v β 3 -expressing tumors xenografted in athymic mice. Tumor uptake for [ 111 In]DOTA-E-c(RGDfK) was 1.73±0.4% ID/g (2 h postinjection) and that of [ 111 In]DOTA-peptidomimetic was 2.04±0.3% ID/g. Tumor uptake for the peptoid-peptide hybrid [ 111 In]DOTA-E-c(nRGDfK) was markedly lower (0.45±0.07% ID/g). The all-peptoid [ 111 In]DOTA-E-c(nRGnDnFnK) did not show specific uptake in tumors (0.11±0.04% ID/g). Conclusions: The peptidomimetic compound and the cyclic RGD peptide have a high affinity for α v β 3 integrin, and these compounds have better tumor-targeting characteristics than the peptoid-peptide hybrid and the all-peptoid

  11. 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.

  12. Effect of Dietary Protein Level on the Expression of Proteins in the Gastrointestinal Tract of Young Pigs.

    Science.gov (United States)

    Ma, Xianyong; Tian, Zhimei; Deng, Dun; Cui, Yiyan; Qiu, Yueqin

    2018-05-02

    The objective of this research is to investigate the effect of protein level on proteins expression in the gastrointestinal tract of young pigs. Eighteen piglets (Duroc × Landrace × Yorkshire) were weaned at 28 days of age and randomly assigned to three diets with 20%, 17%, and 14% CP level, and four essential amino acids, Lys, Met, Thr, and Trp, in three diets met the requirements of weaned piglets. The experimental period lasted 45 days. Compared with the control (20% CP level), the average daily feed intake, the average daily gain, and gain feed ratio of the 17% CP group did not decrease ( P > 0.05), but those of 14% CP group decreased ( P protein digestion and absorption, lipid or carbon digestion and absorption, etc. were up-regulated in 17% CP group, while most of them were down-regulated in 14% CP group. Amino acids metabolism of gastric, pancreatic secretion of duodenum or steroid hormone biosynthesis of jejunum was down-regulated in the 17% CP group, but the lipid metabolism was up-regulated in the 14% CP group. Six proteins were selected for identification by Western-blot, and their changes had the same trend as the proteomics results. The protein level decreased from 20% to 17%, the growth performance was not affected, while the nutrient digestion and absorption or the immune function were improved, which implied that 17% protein level maybe benefit for nutrients absorption of pigs.

  13. Distinct profile of vascular progenitor attachment to extracellular matrix proteins in cancer patients.

    Science.gov (United States)

    Labonté, Laura; Li, Yuhua; Addison, Christina L; Brand, Marjorie; Javidnia, Hedyeh; Corsten, Martin; Burns, Kevin; Allan, David S

    2012-04-01

    Vascular progenitor cells (VPCs) facilitate angiogenesis and initiate vascular repair by homing in on sites of damage and adhering to extracellular matrix (ECM) proteins. VPCs also contribute to tumor angiogenesis and induce angiogenic switching in sites of metastatic cancer. In this study, the binding of attaching cells in VPC clusters that form in vitro on specific ECM proteins was investigated. VPC cluster assays were performed in vitro on ECM proteins enriched in cancer cells and in remodelling tissue. Profiles of VPC clusters from patients with cancer were compared to healthy controls. The role of VEGF and integrin-specific binding of angiogenic attaching cells was addressed. VPC clusters from cancer patients were markedly increased on fibronectin relative to other ECM proteins tested, in contrast to VPC clusters from control subjects, which formed preferentially on laminin. Specific integrin-mediated binding of attaching cells in VPC clusters was matrix protein-dependent. Furthermore, cancer patients had elevated plasma VEGF levels compared to healthy controls and VEGF facilitated preferential VPC cluster formation on fibronectin. Incubating cells from healthy controls with VEGF induced a switch from the 'healthy' VPC binding profile to the profile observed in cancer patients with a marked increase in VPC cluster formation on fibronectin. The ECM proteins laminin and fibronectin support VPC cluster formation via specific integrins on attaching cells and can facilitate patterns of VPC cluster formation that are distinct in cancer patients. Larger studies, however, are needed to gain insight on how tumor angiogenesis may differ from normal repair processes.

  14. 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

  15. 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

  16. Astrocyte-to-neuron communication through integrin-engaged Thy-1/CBP/Csk/Src complex triggers neurite retraction via the RhoA/ROCK pathway.

    Science.gov (United States)

    Maldonado, H; Calderon, C; Burgos-Bravo, F; Kobler, O; Zuschratter, W; Ramirez, O; Härtel, S; Schneider, P; Quest, A F G; Herrera-Molina, R; Leyton, L

    2017-02-01

    Two key proteins for cellular communication between astrocytes and neurons are αvβ3 integrin and the receptor Thy-1. Binding of these molecules in the same (cis) or on adjacent (trans) cellular membranes induces Thy-1 clustering, triggering actin cytoskeleton remodeling. Molecular events that could explain how the Thy-1-αvβ3 integrin interaction signals have only been studied separately in different cell types, and the detailed transcellular communication and signal transduction pathways involved in neuronal cytoskeleton remodeling remain unresolved. Using biochemical and genetic approaches, single-molecule tracking, and high-resolution nanoscopy, we provide evidence that upon binding to αvβ3 integrin, Thy-1 mobility decreased while Thy-1 nanocluster size increased. This occurred concomitantly with inactivation and exclusion of the non-receptor tyrosine kinase Src from the Thy-1/C-terminal Src kinase (Csk)-binding protein (CBP)/Csk complex. The Src inactivation decreased the p190Rho GTPase activating protein phosphorylation, promoting RhoA activation, cofilin, and myosin light chain II phosphorylation and, consequently, neurite shortening. Finally, silencing the adaptor CBP demonstrated that this protein was a key transducer in the Thy-1 signaling cascade. In conclusion, these data support the hypothesis that the Thy-1-CBP-Csk-Src-RhoA-ROCK axis transmitted signals from astrocytic integrin-engaged Thy-1 (trans) to the neuronal actin cytoskeleton. Importantly, the β3 integrin in neurons (cis) was not found to be crucial for neurite shortening. This is the first study to detail the signaling pathway triggered by αvβ3, the endogenous Thy-1 ligand, highlighting the role of membrane-bound integrins as trans acting ligands in astrocyte-neuron communication. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. The predictive nature of transcript expression levels on protein expression in adult human brain.

    Science.gov (United States)

    Bauernfeind, Amy L; Babbitt, Courtney C

    2017-04-24

    Next generation sequencing methods are the gold standard for evaluating expression of the transcriptome. When determining the biological implications of such studies, the assumption is often made that transcript expression levels correspond to protein levels in a meaningful way. However, the strength of the overall correlation between transcript and protein expression is inconsistent, particularly in brain samples. Following high-throughput transcriptomic (RNA-Seq) and proteomic (liquid chromatography coupled with tandem mass spectrometry) analyses of adult human brain samples, we compared the correlation in the expression of transcripts and proteins that support various biological processes, molecular functions, and that are located in different areas of the cell. Although most categories of transcripts have extremely weak predictive value for the expression of their associated proteins (R 2 values of < 10%), transcripts coding for protein kinases and membrane-associated proteins, including those that are part of receptors or ion transporters, are among those that are most predictive of downstream protein expression levels. The predictive value of transcript expression for corresponding proteins is variable in human brain samples, reflecting the complex regulation of protein expression. However, we found that transcriptomic analyses are appropriate for assessing the expression levels of certain classes of proteins, including those that modify proteins, such as kinases and phosphatases, regulate metabolic and synaptic activity, or are associated with a cellular membrane. These findings can be used to guide the interpretation of gene expression results from primate brain samples.

  18. Effect of the level of dietary protein on the utilization of alpha-ketoisocaproate for protein synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Kang, C.W.; Tungsanga, K.; Walser, M.

    1986-04-01

    The efficiency of alpha-ketoisocaproate (KIC) as a dietary substitute for leucine in rats on varying protein intake was estimated by an isotopic method, previously shown to yield the same results as comparative growth experiments. /sup 14/C-KIC and /sup 3/H-leucine are injected orally. Six hours later the ratio, R, of /sup 14/C//sup 3/H in isolated proteins, divided by the same ratio in the injectate is measured. This ratio has been shown to be approximately equal to nutritional efficiency of KIC relative to leucine. As dietary protein increased from 6.3% to 48.3%, whole body protein R decreased from 0.515 +/- 0.045 to 0.299 +/- 0.016. Variations with protein intake were noted in R of protein isolated from individual organs. The magnitude of R in these organs varied two-fold, in the following sequence: brain greater than heart greater than or equal to skeletal muscle greater than or equal to salivary gland greater than or equal to kidney greater than liver. Whole body protein R could be confidently predicted (r2 = 0.992) from R in the protein of kidney and muscle. Thus, the nutritional efficiency of KIC as a dietary substitute for leucine in individual organs as well as in the whole animal is strongly dependent on the level of protein intake.

  19. Effect of the level of dietary protein on the utilization of alpha-ketoisocaproate for protein synthesis

    International Nuclear Information System (INIS)

    Kang, C.W.; Tungsanga, K.; Walser, M.

    1986-01-01

    The efficiency of alpha-ketoisocaproate (KIC) as a dietary substitute for leucine in rats on varying protein intake was estimated by an isotopic method, previously shown to yield the same results as comparative growth experiments. 14 C-KIC and 3 H-leucine are injected orally. Six hours later the ratio, R, of 14 C/ 3 H in isolated proteins, divided by the same ratio in the injectate is measured. This ratio has been shown to be approximately equal to nutritional efficiency of KIC relative to leucine. As dietary protein increased from 6.3% to 48.3%, whole body protein R decreased from 0.515 +/- 0.045 to 0.299 +/- 0.016. Variations with protein intake were noted in R of protein isolated from individual organs. The magnitude of R in these organs varied two-fold, in the following sequence: brain greater than heart greater than or equal to skeletal muscle greater than or equal to salivary gland greater than or equal to kidney greater than liver. Whole body protein R could be confidently predicted (r2 = 0.992) from R in the protein of kidney and muscle. Thus, the nutritional efficiency of KIC as a dietary substitute for leucine in individual organs as well as in the whole animal is strongly dependent on the level of protein intake

  20. 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...

  1. Heritability and genetic basis of protein level variation in an outbred population.

    Science.gov (United States)

    Parts, Leopold; Liu, Yi-Chun; Tekkedil, Manu M; Steinmetz, Lars M; Caudy, Amy A; Fraser, Andrew G; Boone, Charles; Andrews, Brenda J; Rosebrock, Adam P

    2014-08-01

    The genetic basis of heritable traits has been studied for decades. Although recent mapping efforts have elucidated genetic determinants of transcript levels, mapping of protein abundance has lagged. Here, we analyze levels of 4084 GFP-tagged yeast proteins in the progeny of a cross between a laboratory and a wild strain using flow cytometry and high-content microscopy. The genotype of trans variants contributed little to protein level variation between individual cells but explained >50% of the variance in the population's average protein abundance for half of the GFP fusions tested. To map trans-acting factors responsible, we performed flow sorting and bulk segregant analysis of 25 proteins, finding a median of five protein quantitative trait loci (pQTLs) per GFP fusion. Further, we find that cis-acting variants predominate; the genotype of a gene and its surrounding region had a large effect on protein level six times more frequently than the rest of the genome combined. We present evidence for both shared and independent genetic control of transcript and protein abundance: More than half of the expression QTLs (eQTLs) contribute to changes in protein levels of regulated genes, but several pQTLs do not affect their cognate transcript levels. Allele replacements of genes known to underlie trans eQTL hotspots confirmed the correlation of effects on mRNA and protein levels. This study represents the first genome-scale measurement of genetic contribution to protein levels in single cells and populations, identifies more than a hundred trans pQTLs, and validates the propagation of effects associated with transcript variation to protein abundance. © 2014 Parts et al.; Published by Cold Spring Harbor Laboratory Press.

  2. 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

  3. 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

  4. Predicting protein folding pathways at the mesoscopic level based on native interactions between secondary structure elements

    Directory of Open Access Journals (Sweden)

    Sze Sing-Hoi

    2008-07-01

    Full Text Available Abstract Background Since experimental determination of protein folding pathways remains difficult, computational techniques are often used to simulate protein folding. Most current techniques to predict protein folding pathways are computationally intensive and are suitable only for small proteins. Results By assuming that the native structure of a protein is known and representing each intermediate conformation as a collection of fully folded structures in which each of them contains a set of interacting secondary structure elements, we show that it is possible to significantly reduce the conformation space while still being able to predict the most energetically favorable folding pathway of large proteins with hundreds of residues at the mesoscopic level, including the pig muscle phosphoglycerate kinase with 416 residues. The model is detailed enough to distinguish between different folding pathways of structurally very similar proteins, including the streptococcal protein G and the peptostreptococcal protein L. The model is also able to recognize the differences between the folding pathways of protein G and its two structurally similar variants NuG1 and NuG2, which are even harder to distinguish. We show that this strategy can produce accurate predictions on many other proteins with experimentally determined intermediate folding states. Conclusion Our technique is efficient enough to predict folding pathways for both large and small proteins at the mesoscopic level. Such a strategy is often the only feasible choice for large proteins. A software program implementing this strategy (SSFold is available at http://faculty.cs.tamu.edu/shsze/ssfold.

  5. Effects of dietary protein level on growth, health and physiological parameters in growing-furring mink

    DEFF Research Database (Denmark)

    Damgaard, Birthe Marie; Larsen, Peter F.; Clausen, Tove

    2012-01-01

    The aim of the study was to investigate the effects of the dietary protein level and the feeding strategy on growth, health and physiological blood and liver parameters in growing-furring male mink. Effects of dietary protein levels ranging from 22% of metabolizable energy (MEp) to experimental p...

  6. Effect of nonsteroidal antiinflammatory drugs on the C-reactive protein level in rheumatoid arthritis

    DEFF Research Database (Denmark)

    Tarp, Simon; Bartels, Else M.; Bliddal, Henning

    2012-01-01

    To evaluate the effects of oral nonsteroidal antiinflammatory drugs (NSAIDs) on C-reactive protein (CRP) levels in rheumatoid arthritis (RA) patients, with a prespecified focus on the different NSAIDs.......To evaluate the effects of oral nonsteroidal antiinflammatory drugs (NSAIDs) on C-reactive protein (CRP) levels in rheumatoid arthritis (RA) patients, with a prespecified focus on the different NSAIDs....

  7. Effect of dietary protein and energy levels on the growth ...

    African Journals Online (AJOL)

    Dr. A.O. Ani

    While there were significant interactions (P< 0.05) between TBNO and enzyme levels on DM, ... ingredients like soya bean meal, groundnut meal, etc vis- à-vis their acute ... bacterial infection and sulfaquinoxaline drugs against coccidioses.

  8. Respon Pertumbuhan Ayam Lokal Pedaging terhadap Suplementasi Protein Isolasi Biji-bijian (PIB dan Perbedaan Level Protein Ransum

    Directory of Open Access Journals (Sweden)

    M. Aman Yaman

    2009-10-01

    Full Text Available The response of local meat chicken growth to supplementation of isolated grain protein and the difference in ration protein level ABSTRACT. A research which aims to determine the response of local meat chicken growth of protein supplementation with Isolation Grains Protein (IGB and the difference in ration protein level has been conducted in the Laboratory of Experimental Farm, Animal Husbandry Department, Faculty of Agriculture, Syiah Kuala University-Darussalam, Banda Aceh for 90 days. This study used a completely randomized design factorial with 2 factors, consisting of factors namely male gender (JJ and female (JB and the ration is a combination of factors and levels IGB in the ration, ie: treatment A: 17% protein and 0.4% IGB; treatment B 19% protein and 0.6% IGB and treatment C 21% protein and 0.8% IGB. Each combination consisted of 4 replications and each replication consists of 5 chickens. Parameters observed in the study were weight gain, achievement of final weight, consumption, conversion and efficiency of ration. DOC used a derivative result of selection of local meat chicken which are in the process of selection. Data acquired and processed by ANOVA. The results showed that supplementation of IGB and ration protein level difference was significantly effect (P <0.01 on weight gain, final weight, rate of consumption, conversion efficiency of rations and rations, but there is no interaction effect between sex and ration factors . The highest weight gain obtained in the male local chicken achieved by feeding a ration B (93.23 grams, while the hen rations achieved by providing treatment C (63.86 grams / week. The highest final body weight of male chicken on treatment B (1491.5 gram/90 days and hens in treatment C (1061.5 gram/90 days. However, the highest ration consumption in both male and female local chickens obtained from the ration A. Feed conversion value and the best feed efficiency obtained in treatment B for the treatment of

  9. COPS5 (Jab1) protein increases β site processing of amyloid precursor protein and amyloid β peptide generation by stabilizing RanBP9 protein levels.

    Science.gov (United States)

    Wang, Hongjie; Dey, Debleena; Carrera, Ivan; Minond, Dmitriy; Bianchi, Elisabetta; Xu, Shaohua; Lakshmana, Madepalli K

    2013-09-13

    Increased processing of amyloid precursor protein (APP) and accumulation of neurotoxic amyloid β peptide (Aβ) in the brain is central to the pathogenesis of Alzheimer's disease (AD). Therefore, the identification of molecules that regulate Aβ generation is crucial for future therapeutic approaches for AD. We demonstrated previously that RanBP9 regulates Aβ generation in a number of cell lines and primary neuronal cultures by forming tripartite protein complexes with APP, low-density lipoprotein-related protein, and BACE1, consequently leading to increased amyloid plaque burden in the brain. RanBP9 is a scaffold protein that exists and functions in multiprotein complexes. To identify other proteins that may bind RanBP9 and regulate Aβ levels, we used a two-hybrid analysis against a human brain cDNA library and identified COPS5 as a novel RanBP9-interacting protein. This interaction was confirmed by coimmunoprecipitation experiments in both neuronal and non-neuronal cells and mouse brain. Colocalization of COPS5 and RanBP9 in the same subcellular compartments further supported the interaction of both proteins. Furthermore, like RanBP9, COPS5 robustly increased Aβ generation, followed by increased soluble APP-β (sAPP-β) and decreased soluble-APP-α (sAPP-α) levels. Most importantly, down-regulation of COPS5 by siRNAs reduced Aβ generation, implying that endogenous COPS5 regulates Aβ generation. Finally, COPS5 levels were increased significantly in AD brains and APΔE9 transgenic mice, and overexpression of COPS5 strongly increased RanBP9 protein levels by increasing its half-life. Taken together, these results suggest that COPS5 increases Aβ generation by increasing RanBP9 levels. Thus, COPS5 is a novel RanBP9-binding protein that increases APP processing and Aβ generation by stabilizing RanBP9 protein levels.

  10. Multidrug resistance-associated protein-1 (MRP1 genetic variants, MRP1 protein levels and severity of COPD

    Directory of Open Access Journals (Sweden)

    Rutgers Bea

    2010-05-01

    Full Text Available Abstract Background Multidrug resistance-associated protein-1 (MRP1 protects against oxidative stress and toxic compounds generated by cigarette smoking, which is the main risk factor for chronic obstructive pulmonary disease (COPD. We have previously shown that single nucleotide polymorphisms (SNPs in MRP1 significantly associate with level of FEV1 in two independent population based cohorts. The aim of our study was to assess the associations of MRP1 SNPs with FEV1 level, MRP1 protein levels and inflammatory markers in bronchial biopsies and sputum of COPD patients. Methods Five SNPs (rs212093, rs4148382, rs504348, rs4781699, rs35621 in MRP1 were genotyped in 110 COPD patients. The effects of MRP1 SNPs were analyzed using linear regression models. Results One SNP, rs212093 was significantly associated with a higher FEV1 level and less airway wall inflammation. Another SNP, rs4148382 was significantly associated with a lower FEV1 level, higher number of inflammatory cells in induced sputum and with a higher MRP1 protein level in bronchial biopsies. Conclusions This is the first study linking MRP1 SNPs with lung function and inflammatory markers in COPD patients, suggesting a role of MRP1 SNPs in the severity of COPD in addition to their association with MRP1 protein level in bronchial biopsies.

  11. Immunohistochemical localization of integrin alpha V beta 3 and osteopontin suggests that they do not interact during embryo implantation in ruminants

    Directory of Open Access Journals (Sweden)

    MacLaren Leslie A

    2004-04-01

    Full Text Available Abstract Background It has been suggested that trophoblast attachment requires co-expression of integrin alpha V beta 3 and its ligand osteopontin at the fetal-maternal interface. Until now the expression patterns of integrin alpha V beta 3 and osteopontin in the pregnant bovine uterus were unknown. The objectives of this study were to localize integrin alpha V beta 3 and osteopontin in bovine and sheep endometrium during the periimplantation period and to compare the distribution patterns using antibodies that had not yet been tested in sheep. Methods Cell compartments within endometrial tissue sections were scored for immunohistochemical staining intensity and data were analyzed to determine the effects of day of pregnancy or cycle. Results In pregnant bovine endometrium, integrin alpha V beta 3 was detected in luminal epithelium, stroma, myometrium and smooth muscle. A strong band of immunoreactivity was observed in the subepithelial stroma of intercaruncular regions, but there was reduced reactivity in the caruncles and glands. Bovine trophoblast did not express integrin alpha V beta 3 at any stage of pregnancy. In ovine endometrium a different pattern of staining for integrin alpha V beta 3 was observed. Reactivity was not present in the luminal epithelium or trophoblast. There was strong staining of the deep glands and no reactivity in the superficial glands. Osteopontin distribution was similar for sheep and cattle. For both species, apical staining was present on the luminal epithelium and glands and on embryonic tissues. Conclusion In ruminants, integrin alpha V beta 3 and osteopontin do not co-localize at the fetal-maternal interface indicating that these proteins could not interact to facilitate embryo attachment as has been proposed in other species.

  12. [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.

  13. Protein Secondary Structures (α-helix and β-sheet) at a Cellular Level and Protein Fractions in Relation to Rumen Degradation Behaviours of Protein: A New Approach

    International Nuclear Information System (INIS)

    Yu, P.

    2007-01-01

    Studying the secondary structure of proteins leads to an understanding of the components that make up a whole protein, and such an understanding of the structure of the whole protein is often vital to understanding its digestive behaviour and nutritive value in animals. The main protein secondary structures are the α-helix and β-sheet. The percentage of these two structures in protein secondary structures influences protein nutritive value, quality and digestive behaviour. A high percentage of β-sheet structure may partly cause a low access to gastrointestinal digestive enzymes, which results in a low protein value. The objectives of the present study were to use advanced synchrotron-based Fourier transform IR (S-FTIR) microspectroscopy as a new approach to reveal the molecular chemistry of the protein secondary structures of feed tissues affected by heat-processing within intact tissue at a cellular level, and to quantify protein secondary structures using multicomponent peak modelling Gaussian and Lorentzian methods, in relation to protein digestive behaviours and nutritive value in the rumen, which was determined using the Cornell Net Carbohydrate Protein System. The synchrotron-based molecular chemistry research experiment was performed at the National Synchrotron Light Source at Brookhaven National Laboratory, US Department of Energy. The results showed that, with S-FTIR microspectroscopy, the molecular chemistry, ultrastructural chemical make-up and nutritive characteristics could be revealed at a high ultraspatial resolution (∼10 μm). S-FTIR microspectroscopy revealed that the secondary structure of protein differed between raw and roasted golden flaxseeds in terms of the percentages and ratio of α-helixes and β-sheets in the mid-IR range at the cellular level. By using multicomponent peak modelling, the results show that the roasting reduced (P <0.05) the percentage of α-helixes (from 47.1% to 36.1%: S-FTIR absorption intensity), increased the

  14. 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.

  15. GLUCOSE AND TOTAL PROTEIN LEVEL IN LABORATORY RATS UNDER CONDITIONS OF SHORT-TERM FASTING

    Directory of Open Access Journals (Sweden)

    Damir Suljević

    2013-09-01

    Full Text Available Glucose level (UV enzymatic method and total protein level (Biuret method were measured in the blood samples of the rats exposed to short-term starvation. We found a statistically significant increase in the glucose level in experimental animals during starvation, which is also evident in males and females in the experimental group (p <0.05, while decrease in the total protein level was not statistically significant. During starvation, more significant weight loss was observed in females compared to males.Key words: glucose, total protein, serum, Rattus

  16. Silencing of the integrin-linked kinase gene suppresses the proliferation, migration and invasion of pancreatic cancer cells (Panc-1).

    Science.gov (United States)

    Zhu, Xiang-Yu; Liu, Ning; Liu, Wei; Song, Shao-Wei; Guo, Ke-Jian

    2012-04-01

    Integrin-linked kinase (ILK) is an ankyrin repeat-containing serine-threonine protein kinase that is involved in the regulation of integrin-mediated processes such as cancer cell proliferation, migration and invasion. In this study, we examined the effect of a lentivirus-mediated knockdown of ILK on the proliferation, migration and invasion of pancreatic cancer (Panc-1) cells. Immunohistochemical staining showed that ILK expression was enhanced in pancreatic cancer tissue. The silencing of ILK in human Panc-1 cells led to cell cycle arrest in the G0/G1 phase and delayed cell proliferation, in addition to down-regulating cell migration and invasion. The latter effects were mediated by up-regulating the expression of E-cadherin, a key protein in cell adhesion. These findings indicate that ILK may be a new diagnostic marker for pancreatic cancer and that silencing ILK could be a potentially useful therapeutic approach for treating pancreatic cancer.

  17. Silencing of the integrin-linked kinase gene suppresses the proliferation, migration and invasion of pancreatic cancer cells (Panc-1

    Directory of Open Access Journals (Sweden)

    Xiang-Yu Zhu

    2012-01-01

    Full Text Available Integrin-linked kinase (ILK is an ankyrin repeat-containing serine-threonine protein kinase that is involved in the regulation of integrin-mediated processes such as cancer cell proliferation, migration and invasion. In this study, we examined the effect of a lentivirus-mediated knockdown of ILK on the proliferation, migration and invasion of pancreatic cancer (Panc-1 cells. Immunohistochemical staining showed that ILK expression was enhanced in pancreatic cancer tissue. The silencing of ILK in human Panc-1 cells led to cell cycle arrest in the G0/G1 phase and delayed cell proliferation, in addition to down-regulating cell migration and invasion. The latter effects were mediated by up-regulating the expression of E-cadherin, a key protein in cell adhesion. These findings indicate that ILK may be a new diagnostic marker for pancreatic cancer and that silencing ILK could be a potentially useful therapeutic approach for treating pancreatic cancer.

  18. Effect of dietary crude protein level on the performance and ...

    African Journals Online (AJOL)

    ویرایه

    2013-06-26

    Jun 26, 2013 ... kids who were 86 ± 3 days old with live weight of 9 ± 03 kg were used in a completely randomized design. ... matter intake (DMI) than the kids fed with 10.5, 12.8, .... black goats fed with 18% CP level with 20, 16 and 14%.

  19. Sublethal Effects of Diesel on Total Protein Levels and Cholesterol ...

    African Journals Online (AJOL)

    Michael Horsfall

    were handpicked at the Eagle Cement area of the New Calabar River and subjected to different levels ... groups when compared to the control in both the muscle and the viscera of the periwinkle. ... In Nigeria, oil industry operations are both offshore and onshore. ... This acts as a means of assessing the hazard or potential ...

  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. High-level expression of soluble recombinant proteins in Escherichia coli using an HE-maltotriose-binding protein fusion tag.

    Science.gov (United States)

    Han, Yingqian; Guo, Wanying; Su, Bingqian; Guo, Yujie; Wang, Jiang; Chu, Beibei; Yang, Guoyu

    2018-02-01

    Recombinant proteins are commonly expressed in prokaryotic expression systems for large-scale production. The use of genetically engineered affinity and solubility enhancing fusion proteins has increased greatly in recent years, and there now exists a considerable repertoire of these that can be used to enhance the expression, stability, solubility, folding, and purification of their fusion partner. Here, a modified histidine tag (HE) used as an affinity tag was employed together with a truncated maltotriose-binding protein (MBP; consisting of residues 59-433) from Pyrococcus furiosus as a solubility enhancing tag accompanying a tobacco etch virus protease-recognition site for protein expression and purification in Escherichia coli. Various proteins tagged at the N-terminus with HE-MBP(Pyr) were expressed in E. coli BL21(DE3) cells to determine expression and solubility relative to those tagged with His6-MBP or His6-MBP(Pyr). Furthermore, four HE-MBP(Pyr)-fused proteins were purified by immobilized metal affinity chromatography to assess the affinity of HE with immobilized Ni 2+ . Our results showed that HE-MBP(Pyr) represents an attractive fusion protein allowing high levels of soluble expression and purification of recombinant protein in E. coli. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. 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

    Full Text Available Tissue organization during embryonic development and wound healing depends on the ability of cells on the one hand to exchange adhesive bonds during active rearrangement and on the other to become fixed in place as tissue homeostasis is reached. Cells achieve these contradictory tasks by regulating either cell-cell adhesive bonds, mediated by cadherins, or cell-extracellular matrix (ECM connections, regulated by integrins. Integrin alpha5beta1 and soluble fibronectin (sFN are key players in cell-ECM force generation and in ECM polymerization. Here, we explore the interplay between integrin alpha5beta1 and sFN and its influence on tissue mechanical properties and cell sorting behavior.We generated a series of cell lines varying in alpha5beta1 receptor density. We then systematically explored the effects of different sFN concentrations on aggregate biomechanical properties using tissue surface tensiometry. We found previously unreported complex behaviors including the observation that interactions between fibronectin and integrin alpha5beta1 generates biphasic tissue cohesion profiles. Specifically, we show that at constant sFn concentration, aggregate cohesion increases linearly as alpha5beta1 receptor density is increased from low to moderate levels, producing a transition from viscoelastic-liquid to pseudo viscoelastic-solid behavior. However, further increase in receptor density causes an abrupt drop in tissue cohesion and a transition back to viscoelastic-liquid properties. We propose that this may be due to depletion of sFn below a critical value in the aggregate microenvironment at high alpha5beta1 levels. We also show that differential expression of alpha5beta1 integrin can promote phase-separation between cells.The interplay between alpha5-integrin and sFn contributes significantly to tissue cohesion and, depending on their level of expression, can mediate a shift from liquid to elastic behavior. This interplay represents a tunable level

  4. 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.

  5. 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

  6. Influence of protein level and supplemental methionine in practical rations for young endangered masked bobwhite quail

    Science.gov (United States)

    Serafin, J.A.

    1982-01-01

    A study was conducted to examine the protein requirement of young endangered masked Bobwhite quail (Colinus virginianus ridgwayi). Five practical starting rations containing 24 to 32% protein were fed alone and supplemented with methionine for 5 weeks. Supplemental methionine significantly improved growth of quail fed diets containing 24 and 26% protein. Increasing the protein level improved growth of quail fed unsupplemented diets but did not do so when diets contained supplemental methionine. A methionine-supplemented ration containing 24% protein appeared adequate for supporting rapid growth of masked Bobwhite quail.

  7. 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.

  8. The effect of serum magnesium levels and serum endothelin-1 levels on bone mineral density in protein energy malnutrition.

    Science.gov (United States)

    Ozturk, C F; Karakelleoglu, C; Orbak, Z; Yildiz, L

    2012-06-01

    An inadequate and imbalanced intake of protein and energy results in protein-energy malnutrition (PEM). It is known that bone mineral density and serum magnesium levels are low in malnourished children. However, the roles of serum magnesium and endothelin-1 (ET-1) levels in the pathophysiology of bone mineralization are obscure. Thus, the relationships between serum magnesium and ET-1 levels and the changes in bone mineral density were investigated in this study. There was a total of 32 subjects, 25 of them had PEM and seven were controls. While mean serum ET-1 levels of the children with kwashiorkor and marasmus showed no statistically significant difference, mean serum ET-1 levels of both groups were significantly higher than that of the control group. Serum magnesium levels were lower than normal value in 9 (36%) of 25 malnourished children. Malnourished children included in this study were divided into two subgroups according to their serum magnesium levels. While mean serum ET-1 levels in the group with low magnesium levels were significantly higher than that of the group with normal magnesium levels (p malnutrition. Our study suggested that lower magnesium levels and higher ET-1 levels might be important factors in changes of bone mineral density in malnutrition. We recommend that the malnourished patients, especially with hypomagnesaemia, should be treated with magnesium early.

  9. Synergistic Control of Kinetochore Protein Levels by Psh1 and Ubr2.

    Directory of Open Access Journals (Sweden)

    Eva Herrero

    2016-02-01

    Full Text Available The accurate segregation of chromosomes during cell division is achieved by attachment of chromosomes to the mitotic spindle via the kinetochore, a large multi-protein complex that assembles on centromeres. The budding yeast kinetochore comprises more than 60 different proteins. Although the structure and function of many of these proteins has been investigated, we have little understanding of the steady state regulation of kinetochores. The primary model of kinetochore homeostasis suggests that kinetochores assemble hierarchically from the centromeric DNA via the inclusion of a centromere-specific histone into chromatin. We tested this model by trying to perturb kinetochore protein levels by overexpressing an outer kinetochore gene, MTW1. This increase in protein failed to change protein recruitment, consistent with the hierarchical assembly model. However, we find that deletion of Psh1, a key ubiquitin ligase that is known to restrict inner kinetochore protein loading, does not increase levels of outer kinetochore proteins, thus breaking the normal kinetochore stoichiometry. This perturbation leads to chromosome segregation defects, which can be partially suppressed by mutation of Ubr2, a second ubiquitin ligase that normally restricts protein levels at the outer kinetochore. Together these data show that Psh1 and Ubr2 synergistically control the amount of proteins at the kinetochore.

  10. Association between protein C levels and mortality in patients with advanced prostate, lung and pancreatic cancer.

    Science.gov (United States)

    Wilts, I T; Hutten, B A; Meijers, J C M; Spek, C A; Büller, H R; Kamphuisen, P W

    2017-06-01

    Procoagulant factors promote cancer progression and metastasis. Protein C is involved in hemostasis, inflammation and signal transduction, and has a protective effect on the endothelial barrier. In mice, administration of activated protein C reduced experimental metastasis. We assessed the association between protein C and mortality in patients with three types of cancer. The study population consisted of patients with advanced prostate, non-small cell lung or pancreatic cancer, who participated in the INPACT trial (NCT00312013). The trial evaluated the addition of nadroparin to chemotherapy in patients with advanced malignancy. Patients were divided into tertiles based on protein C at baseline. The association between protein C levels and mortality was evaluated with Cox proportional hazard models. We analysed 477 patients (protein C tertiles: C level was 107% (IQR 92-129). In the lowest tertile, 75 patients per 100 patient-years died, as compared to 60 and 54 in the middle and high tertile, respectively. Lower levels of protein C were associated with increased mortality (in tertiles: HR for trend 1.18, 95%CI 1.02-1.36, adjusted for age, sex and nadroparin use; as a continuous variable: HR 1.004, 95%CI 1.00-1.008, p=0.07). Protein C seems inversely associated with mortality in patients with advanced prostate, lung and pancreatic cancer. Further research should validate protein C as a biomarker for mortality, and explore the effects of protein C on progression of cancer. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Protein levels and colony development of Africanized and European honey bees fed natural and artificial diets.

    Science.gov (United States)

    Morais, M M; Turcatto, A P; Pereira, R A; Francoy, T M; Guidugli-Lazzarini, K R; Gonçalves, L S; de Almeida, J M V; Ellis, J D; De Jong, D

    2013-12-19

    Pollen substitute diets are a valuable resource for maintaining strong and health honey bee colonies. Specific diets may be useful in one region or country and inadequate or economically unviable in others. We compared two artificial protein diets that had been formulated from locally-available ingredients in Brazil with bee bread and a non-protein sucrose diet. Groups of 100 newly-emerged, adult workers of Africanized honey bees in Brazil and European honey bees in the USA were confined in small cages and fed on one of four diets for seven days. The artificial diets included a high protein diet made of soy milk powder and albumin, and a lower protein level diet consisting of soy milk powder, brewer's yeast and rice bran. The initial protein levels in newly emerged bees were approximately 18-21 µg/µL hemolymph. After feeding on the diets for seven days, the protein levels in the hemolymph were similar among the protein diet groups (~37-49 µg/µL after seven days), although Africanized bees acquired higher protein levels, increasing 145 and 100% on diets D1 and D2, respectively, versus 83 and 60% in the European bees. All the protein diets resulted in significantly higher levels of protein than sucrose solution alone. In the field, the two pollen substitute diets were tested during periods of low pollen availability in the field in two regions of Brazil. Food consumption, population development, colony weight, and honey production were evaluated to determine the impact of the diets on colony strength parameters. The colonies fed artificial diets had a significant improvement in all parameters, while control colonies dwindled during the dearth period. We conclude that these two artificial protein diets have good potential as pollen substitutes during dearth periods and that Africanized bees more efficiently utilize artificial protein diets than do European honey bees.

  12. Development, Characterization, and Optimization of Protein Level in Date Bars Using Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Muhammad Nadeem

    2012-01-01

    Full Text Available This project was designed to produce a nourishing date bar with commercial value especially for school going children to meet their body development requirements. Protein level of date bars was optimized using response surface methodology (RSM. Economical and underutilized sources, that is, whey protein concentrate and vetch protein isolates, were explored for protein supplementation. Fourteen date bar treatments were produced using a central composite design (CCD with 2 variables and 3 levels for each variable. Date bars were then analyzed for nutritional profile. Proximate composition revealed that addition of whey protein concentrate and vetch protein isolates improved the nutritional profile of date bars. Protein level, texture, and taste were considerably improved by incorporating 6.05% whey protein concentrate and 4.35% vetch protein isolates in date bar without affecting any sensory characteristics during storage. Response surface methodology was observed as an economical and effective tool to optimize the ingredient level and to discriminate the interactive effects of independent variables.

  13. Collagen fibrillogenesis: fibronectin, integrins, and minor collagens as organizers and nucleators.

    Science.gov (United States)

    Kadler, Karl E; Hill, Adele; Canty-Laird, Elizabeth G

    2008-10-01

    Collagens are triple helical proteins that occur in the extracellular matrix (ECM) and at the cell-ECM interface. There are more than 30 collagens and collagen-related proteins but the most abundant are collagens I and II that exist as D-periodic (where D = 67 nm) fibrils. The fibrils are of broad biomedical importance and have central roles in embryogenesis, arthritis, tissue repair, fibrosis, tumor invasion, and cardiovascular disease. Collagens I and II spontaneously form fibrils in vitro, which shows that collagen fibrillogenesis is a selfassembly process. However, the situation in vivo is not that simple; collagen I-containing fibrils do not form in the absence of fibronectin, fibronectin-binding and collagen-binding integrins, and collagen V. Likewise, the thin collagen II-containing fibrils in cartilage do not form in the absence of collagen XI. Thus, in vivo, cellular mechanisms are in place to control what is otherwise a protein self-assembly process. This review puts forward a working hypothesis for how fibronectin and integrins (the organizers) determine the site of fibril assembly, and collagens V and XI (the nucleators) initiate collagen fibrillogenesis.

  14. human serum protein and c-reactive protein levels among hiv ...

    African Journals Online (AJOL)

    2016-09-30

    Sep 30, 2016 ... inflammation used to monitor HIV infection (Pepys and Hirschfield, 2003; Baker et al., 2010; Funderburg et al., 2010;. Neuhaus et ... from microbial infections, the CRP concentration can rise up to 300mg/L in 12-24 hours (Le Carrer et al., 1995; Vaishnavi,. 1996 ..... (pentaxins) and serum amyloid A protein.

  15. Animal Protein intake and the Effect of age on the level of Protein ...

    African Journals Online (AJOL)

    Some of the items such as eggs, milk and poultry meat were not consumed in reasonable quantities due to poor economic situation of the family. The results suggested that except for the fathers, other groups such as mothers and children were consuming animal protein below the quantity required by them. JARD Vol.

  16. 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

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

    Science.gov (United States)

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

    2018-05-01

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

  18. 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...

  19. Kaempferol inhibits the production of ROS to modulate OPN-αvβ3 integrin pathway in HUVECs.

    Science.gov (United States)

    Xiao, Hong-Bo; Lu, Xiang-Yang; Liu, Zi-Kui; Luo, Zhi-Feng

    2016-06-01

    In the present study, we tested the hypothesis that aldosterone regulates osteopontin (OPN)-related signaling pathways to promote nuclear factor κB (NF-κB) activation in primary human umbilical vein endothelial cells (HUVECs) and that kaempferol, a flavonoid compound, blocks those changes. Aldosterone induced productions of reactive oxygen species (ROS), OPN, interleukin-6 (IL-6), and tumor necrosis factor alpha (TNF-α) and expression of nicotinamide adenine dinucleotide phosphate-oxidase 4 (Nox4), NF-κB, OPN, alphavbeta3 (αvβ3) integrin, and inhibitor of NF-κB alpha phosphorylation (P-IκBα) in HUVEC. HUVECs were pretreated with kaempferol (0, 1, 3, or 10 μM) for 1 h and exposed to aldosterone (10(-6) M) for 24 h. Kaempferol reduced ROS, OPN, NF-κB, IL-6, and TNF-α levels; Nox4, αvβ3 integrin; and P-IκBα expressions. The effect of aldosterone was also abrogated by spironolactone (10(-6) M). In addition, vitamin C (20 mmol/L) reduced ROS production. Vitamin C and LM609 (10 μg/mL) treatment decreased expressions of OPN, αvβ3 integrin, and NF-κB (P kaempferol may modulate OPN-αvβ3 integrin pathway to inhibit NF-κB activation in HUVECs.

  20. Multi-level learning: improving the prediction of protein, domain and residue interactions by allowing information flow between levels

    Directory of Open Access Journals (Sweden)

    McDermott Drew

    2009-08-01

    Full Text Available Abstract Background Proteins interact through specific binding interfaces that contain many residues in domains. Protein interactions thus occur on three different levels of a concept hierarchy: whole-proteins, domains, and residues. Each level offers a distinct and complementary set of features for computationally predicting interactions, including functional genomic features of whole proteins, evolutionary features of domain families and physical-chemical features of individual residues. The predictions at each level could benefit from using the features at all three levels. However, it is not trivial as the features are provided at different granularity. Results To link up the predictions at the three levels, we propose a multi-level machine-learning framework that allows for explicit information flow between the levels. We demonstrate, using representative yeast interaction networks, that our algorithm is able to utilize complementary feature sets to make more accurate predictions at the three levels than when the three problems are approached independently. To facilitate application of our multi-level learning framework, we discuss three key aspects of multi-level learning and the corresponding design choices that we have made in the implementation of a concrete learning algorithm. 1 Architecture of information flow: we show the greater flexibility of bidirectional flow over independent levels and unidirectional flow; 2 Coupling mechanism of the different levels: We show how this can be accomplished via augmenting the training sets at each level, and discuss the prevention of error propagation between different levels by means of soft coupling; 3 Sparseness of data: We show that the multi-level framework compounds data sparsity issues, and discuss how this can be dealt with by building local models in information-rich parts of the data. Our proof-of-concept learning algorithm demonstrates the advantage of combining levels, and opens up

  1. 99mTc-Labeled Cyclic RGD Peptides for Noninvasive Monitoring of Tumor Integrin αvβ3 Expression

    Directory of Open Access Journals (Sweden)

    Yang Zhou

    2011-09-01

    Full Text Available This report describes the biologic evaluations of [99mTc(HYNIC-3P-RGD2(tricine(TPPTS] (99mTc-3P-RGD2: 6-hydrazinonicotinyl; 3P-RGD2 = PEG4-E[PEG4-c(RGDfK]2; PEG4 = 15-amino-4,7,10,13-tetraoxapentadecanoic acid; and TPPTS = trisodium triphenylpho-sphine-3,3′,3“-trisulfonate, [99mTc(HYNIC-3G-RGD2(tricine(TPPTS] (99mTc-3G-RGD2: 3G-RGD2 = G3-E[G3-c(RGDfK]2 and G3 = Gly-Gly-Gly, and 99mTcO(MAG2−3G-RGD2 (MAG2 = mercaptoacetylglycylglycyl as radiotracers for noninvasive imaging of tumor integrin αvβ3 expression in five xenografted tumor-bearing models. Biodistribution and imaging studies were performed in athymic nude mice bearing U87MG, MDA-MB-435, A549, HT29, or PC-3 tumor xenografts. Immunochemistry was performed using the cultured primary tumor cells and xenografted tumor tissues. It was found that the radiotracer tumor uptake followed the trend U87MG > MDA-MB-435 ≈ HT29 ≈ A549 > PC-3. The total integrin β3 expression levels followed the general trend: U87MG > MDA-MB-435 ≈ A549~HT29 > PC-3. There is a linear relationship between the radiotracer injected dose per gram tumor uptake and the total integrin β3 expression levels. On the basis of these, it was concluded that radiotracer tumor uptake is contributed by integrin αVβ3 expressed on tumor cells and activated endothelial cells of the tumor neovasculature. 99mTc-3P-RGD2 has the capability to monitor integrin αvβ3 expression in a noninvasive fashion.

  2. Differential proteomics study of platelets in asymptomatic constitutional macrothrombocytopenia: altered levels of cytoskeletal proteins.

    Science.gov (United States)

    Karmakar, Shilpita; Saha, Sutapa; Banerjee, Debasis; Chakrabarti, Abhijit

    2015-01-01

    Harris platelet syndrome (HPS), also known as asymptomatic constitutional macrothrombocytopenia (ACMT), is an autosomal dominant platelet disorder characterized by mild-to-severe thrombocytopenia and giant platelets with normal platelet aggregation and absence of bleeding symptoms. We have attempted a comparative proteomics study for profiling of platelet proteins in healthy vs. pathological states to discover characteristic protein expression changes in macrothrombocytes and decipher the factors responsible for the functionally active yet morphologically distinct platelets. We have used 2-D gel-based protein separation techniques coupled with MALDI-ToF/ToF-based mass spectrometric identification and characterization of the proteins to investigate the differential proteome profiling of platelet proteins isolated from the peripheral blood samples of patients and normal volunteers. Our study revealed altered levels of actin-binding proteins such as myosin light chain, coactosin-like protein, actin-related protein 2/3 complex, and transgelin2 that hint toward the cytoskeletal changes necessary to maintain the structural and functional integrity of macrothrombocytes. We have also observed over expressed levels of peroxiredoxin2 that signifies the prevailing oxidative stress in these cells. Additionally, altered levels of protein disulfide isomerase and transthyretin provide insights into the measures adapted by the macrothrombocytes to maintain their normal functional activity. This first proteomics study of platelets from ACMT may provide an understanding of the structural stability and normal functioning of these platelets in spite of their large size. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  3. Less is More: Membrane Protein Digestion Beyond Urea–Trypsin Solution for Next-level Proteomics*

    Science.gov (United States)

    Zhang, Xi

    2015-01-01

    The goal of next-level bottom-up membrane proteomics is protein function investigation, via high-coverage high-throughput peptide-centric quantitation of expression, modifications and dynamic structures at systems scale. Yet efficient digestion of mammalian membrane proteins presents a daunting barrier, and prevalent day-long urea–trypsin in-solution digestion proved insufficient to reach this goal. Many efforts contributed incremental advances over past years, but involved protein denaturation that disconnected measurement from functional states. Beyond denaturation, the recent discovery of structure/proteomics omni-compatible detergent n-dodecyl-β-d-maltopyranoside, combined with pepsin and PNGase F columns, enabled breakthroughs in membrane protein digestion: a 2010 DDM-low-TCEP (DLT) method for H/D-exchange (HDX) using human G protein-coupled receptor, and a 2015 flow/detergent-facilitated protease and de-PTM digestions (FDD) for integrative deep sequencing and quantitation using full-length human ion channel complex. Distinguishing protein solubilization from denaturation, protease digestion reliability from theoretical specificity, and reduction from alkylation, these methods shifted day(s)-long paradigms into minutes, and afforded fully automatable (HDX)-protein-peptide-(tandem mass tag)-HPLC pipelines to instantly measure functional proteins at deep coverage, high peptide reproducibility, low artifacts and minimal leakage. Promoting—not destroying—structures and activities harnessed membrane proteins for the next-level streamlined functional proteomics. This review analyzes recent advances in membrane protein digestion methods and highlights critical discoveries for future proteomics. PMID:26081834

  4. Impact of High-Level Expression of Heterologous Protein on Lactococcus lactis Host.

    Science.gov (United States)

    Kim, Mina; Jin, Yerin; An, Hyun-Joo; Kim, Jaehan

    2017-07-28

    The impact of overproduction of a heterologous protein on the metabolic system of host Lactococcus lactis was investigated. The protein expression profiles of L. lactis IL1403 containing two near-identical plasmids that expressed high- and low-level of the green fluorescent protein (GFP) were examined via shotgun proteomics. Analysis of the two strains via high-throughput LC-MS/MS proteomics identified the expression of 294 proteins. The relative amount of each protein in the proteome of both strains was determined by label-free quantification using the spectral counting method. Although expression level of most proteins were similar, several significant alterations in metabolic network were identified in the high GFP-producing strain. These changes include alterations in the pyruvate fermentation pathway, oxidative pentose phosphate pathway, and de novo synthesis pathway for pyrimidine RNA. Expression of enzymes for the synthesis of dTDP-rhamnose and N -acetylglucosamine from glucose was suppressed in the high GFP strain. In addition, enzymes involved in the amino acid synthesis or interconversion pathway were downregulated. The most noticeable changes in the high GFP-producing strain were a 3.4-fold increase in the expression of stress response and chaperone proteins and increase of caseinolytic peptidase family proteins. Characterization of these host expression changes witnessed during overexpression of GFP was might suggested the metabolic requirements and networks that may limit protein expression, and will aid in the future development of lactococcal hosts to produce more heterologous protein.

  5. Genetic regulation ofmethylation and IL1RL1-a protein levels in asthma

    NARCIS (Netherlands)

    Dijk, F Nicole; Xu, Chengjian; Melén, Erik; Carsin, Anne-Elie; Kumar, Asish; Nolte, Ilja M; Gruzieva, Olena; Pershagen, Goran; Grotenboer, Neomi S; Savenije, Olga E M; Antó, Josep Maria; Lavi, Iris; Dobaño, Carlota; Bousquet, Jean; van der Vlies, Pieter; van der Valk, Ralf J P; de Jongste, Johan C; Nawijn, Martijn C; Guerra, Stefano; Postma, Dirkje S; Koppelman, Gerard H

    2018-01-01

    Interleukin-1 receptor-like 1 (IL1RL1) is an important asthma gene. (Epi)genetic regulation ofIL1RL1protein expression has not been established. We assessed the association betweenIL1RL1single nucleotide polymorphisms (SNPs),IL1RL1methylation and serum IL1RL1-a protein levels, and aimed to identify

  6. Effect of different protein levels on the growth performance of African ...

    African Journals Online (AJOL)

    There were no significant differences (P.0.05) among treatments in initial body weight, protein efficiency ratio, average shell weight, average visceral weight, average edible weight and feed cost per kg weight gain. The results obtained in this study show that dietary protein level of about 22% is adequate for the growth of ...

  7. 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.

  8. Multiple proteins of White spot syndrome virus involved in ...

    Indian Academy of Sciences (India)

    The recognition and attachment of virus to its host cell surface is a critical step for viral infection. Recent research revealed that -integrin was involved in White spot syndrome virus (WSSV) infection. In this study, the interaction of -integrin with structure proteins of WSSV and motifs involved in WSSV infection was ...

  9. Modulation of GDP-fucose level for generating proteins with reduced rate of fucosylation (WO2010141855).

    Science.gov (United States)

    Taupin, Philippe

    2011-09-01

    The application (WO2010141855) is in the field of glycobiology, and involves the control of the rate of fucosylation of proteins by exogenous factors. It aims at controlling the rate of protein fucosylation with inhibitors (drugs or nucleic acid antagonists) of enzymes involved in the synthesis of GDP-fucose. Mammalian cell lines were cultured in the presence of inhibitors, for example, siRNA. The rates of GDP-fucose in cells and during protein fucosylation were characterized. The level of protein fucosylation decreases rapidly in response to a decrease in GDP-fucose level. The relationship between the rate of fucosylation of proteins and the level of GDP-fucose in a cell is non-linear. Reduction in the rate of protein fucosylation can be achieved with a minimal reduction of the level of GDP-fucose in cells. The paradigm may be used to synthesize proteins and antibodies, with a reduced rate of fucosylation. The application claims that the use of drugs or nucleic acid antagonists that inhibit the enzymes involved in GDP-fucose biosynthesis optimizes the level of GDP-fucose present in cells, and reduces the rate of fucosylation of glycoproteins.

  10. Utilizing Biotinylated Proteins Expressed in Yeast to Visualize DNA–Protein Interactions at the Single-Molecule Level

    Directory of Open Access Journals (Sweden)

    Huijun Xue

    2017-10-01

    Full Text Available Much of our knowledge in conventional biochemistry has derived from bulk assays. However, many stochastic processes and transient intermediates are hidden when averaged over the ensemble. The powerful technique of single-molecule fluorescence microscopy has made great contributions to the understanding of life processes that are inaccessible when using traditional approaches. In single-molecule studies, quantum dots (Qdots have several unique advantages over other fluorescent probes, such as high brightness, extremely high photostability, and large Stokes shift, thus allowing long-time observation and improved signal-to-noise ratios. So far, however, there is no convenient way to label proteins purified from budding yeast with Qdots. Based on BirA–Avi and biotin–streptavidin systems, we have established a simple method to acquire a Qdot-labeled protein and visualize its interaction with DNA using total internal reflection fluorescence microscopy. For proof-of-concept, we chose replication protein A (RPA and origin recognition complex (ORC as the proteins of interest. Proteins were purified from budding yeast with high biotinylation efficiency and rapidly labeled with streptavidin-coated Qdots. Interactions between proteins and DNA were observed successfully at the single-molecule level.

  11. Caveolin 3-mediated integrin β1 signaling is required for the proliferation of folliculostellate cells in rat anterior pituitary gland under the influence of extracellular matrix.

    Science.gov (United States)

    Horiguchi, Kotaro; Fujiwara, Ken; Ilmiawati, Cimi; Kikuchi, Motoshi; Tsukada, Takehiro; Kouki, Tom; Yashiro, Takashi

    2011-07-01

    Folliculostellate (FS) cells in the anterior pituitary gland are believed to have multifunctional properties. Using transgenic rats that express green fluorescent protein (GFP) specifically in FS cells in the anterior pituitary gland (S100b-GFP rats), we recently revealed that FS cells in primary culture exhibited marked proliferation in the presence of laminin, an extracellular matrix (ECM) component of the basement membrane. In a process referred to as matricrine action, FS cells receive ECM as a signal through their receptors, which results in morphological and functional changes. In this study, we investigated matricrine signaling in FS cells and observed that the proliferation of FS cells is mediated by integrin β1, which is involved in various signaling pathways for cell migration and proliferation in response to ECM. Then, we analyzed downstream events of the integrin β1 signaling pathway in the proliferation of FS cells and identified caveolin 3 as a potential candidate molecule. Caveolin 3 is a membrane protein that binds cholesterol and a number of signaling molecules that interact with integrin β1. Using specific small interfering RNA of caveolin 3, the proliferation of FS cells was inhibited. Furthermore, caveolin 3 drove activation of the mitogen-activated protein kinase (MAPK) signaling cascades, which resulted in upregulation of cyclin D1 in FS cells. These findings suggest that matricrine signaling in the proliferation of FS cells was transduced by a caveolin 3-mediated integrin β1 signaling pathway and subsequent activation of the MAPK pathway. © 2011 Society for Endocrinology

  12. Nitrogen balance study in young Nigerian adult males using four levels of protein intake.

    Science.gov (United States)

    Atinmo, T; Mbofung, C M; Egun, G; Osotimehin, B

    1988-11-01

    1. The present study was carried out to estimate precisely, via the nitrogen balance technique, the protein requirement of Nigerians (earlier estimated via the obligatory N method) using graded levels of protein intake. 2. Fifteen medical students of the University of Ibadan who volunteered to participate in the study were given graded levels of protein (0.3, 0.45, 0.6 and 0.75 g/kg body-weight per d) derived from foods similar to those usually consumed by the subjects. 3. Each subject was given each of the dietary protein levels for a period of 10 d. Subjects were divided into two groups and the feeding pattern followed a criss-cross design with one group starting with the highest level of protein intake (0.3 g). Mean energy intake during each of the eleven experimental periods was maintained at 0.2 MJ/kg per d. After an initial 5 d adaptation period in each experimental period, 24 h urine and faecal samples were collected in marked containers for five consecutive days for N determination. 4. Mean N balance during consumption of the four protein levels (0.30, 0.45, 0.6 and 0.75 g/kg) were -11.02 (SD 8.07), -9.90 (SD 6.64), +9.70 (SD 4.15) and +5.13 (SD 4.62) respectively. Using regression analysis, the mean daily N requirement was estimated at 110.25 mg N/kg body-weight (0.69 g protein/kg body-weight). Estimates of allowances for individual variations to cover 97.5% of the population adjusted this value to 0.75 g protein/kg body-weight. Net protein utilization for the diet at maintenance level was estimated at 57.5.

  13. Syndecan-2 is a novel ligand for the protein tyrosine phosphatase receptor CD148

    DEFF Research Database (Denmark)

    Whiteford, James R; Xian, Xiaojie; Chaussade, Claire

    2011-01-01

    Syndecan-2 is a heparan sulfate proteoglycan that has a cell adhesion regulatory domain contained within its extracellular core protein. Cell adhesion to the syndecan-2 extracellular domain (S2ED) is ß1 integrin dependent; however, syndecan-2 is not an integrin ligand. Here the protein tyrosine...

  14. 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...

  15. 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.

  16. Protein intake and stress levels in nurses and housewives of Pakistan

    Science.gov (United States)

    Wattoo, Feroza Hamid; Memon, Muhammad Saleh; Memon, Allah Nawaz; Wattoo, Muhammad Hamid Sarwar; Asad, Muhammad Javaid; Siddique, Farzana

    2011-01-01

    Stress has many biological effects on human daily life. In the present study, dietary protein intake was correlated with the investigated stress levels of nurses and housewives of the targeted urban population. Age group ranged from 30 to 45 years and both the groups belonged to middle socioeconomic status. After calculations of environmental, psychological and physiological stresses, it was observed that the levels of stress in housewives were significantly higher than those of nurses. Recommended dietary allowances, RDA and actual protein intakes, API were also compared in both the groups. The found protein intake was less in housewives as compared to that of nurses. PMID:23961140

  17. Comparison of protein degradation, protein oxidation, and μ-calpain activation between pale, soft, and exudative and red, firm, and nonexudative pork during postmortem aging.

    Science.gov (United States)

    Yin, Y; Zhang, W G; Zhou, G H; Guo, B

    2014-08-01

    The objective of this study was to investigate the differences in protein modifications between pale, soft, and exudative (PSE) and red, firm, and nonexudative (RFN) pork during postmortem (PM) aging. Longissimus dorsi (LD) including 8 PSE and 8 RFN muscles were individually removed from 16 carcasses. These 16 LD muscles were vacuum packaged at 24 h after slaughter and stored at 4°C for 1, 3, and 5 d. The centrifugation loss, drip loss, color, protein solubility, protein oxidation, protein degradation including desmin, troponin T, and integrin, and μ-calpain activation were determined. The pH of PSE samples was significantly lower than that of RFN samples at both 1 and 24 h PM (P 0.05). In addition, PSE pork presented a lower solubility of sarcoplasmic protein, myofibrillar protein, and total protein than RFN pork except the solubility of myofibrillar protein at d 1 (P firm, and nonexudative pork presented lower intensity of intact 80 kDa calpain and greater intensity of autolyzed 76 kDa product compared to PSE pork (P < 0.01). The results indicate that the degree of μ-calpain activation, the extent of protein degradation including desmin and integrin, and the level of protein solubility in PSE pork could contribute to its low water holding capacity during PM storage.

  18. The Role of Integrin α6 (CD49f) in Stem Cells: More than a Conserved Biomarker.

    Science.gov (United States)

    Krebsbach, Paul H; Villa-Diaz, Luis G

    2017-08-01

    Stem cells have the capacity for self-renewal and differentiation into specialized cells that form and repopulated all tissues and organs, from conception to adult life. Depending on their capacity for differentiation, stem cells are classified as totipotent (ie, zygote), pluripotent (ie, embryonic stem cells), multipotent (ie, neuronal stem cells, hematopoietic stem cells, epithelial stem cells, etc.), and unipotent (ie, spermatogonial stem cells). Adult or tissue-specific stem cells reside in specific niches located in, or nearby, their organ or tissue of origin. There, they have microenvironmental support to remain quiescent, to proliferate as undifferentiated cells (self-renewal), and to differentiate into progenitors or terminally differentiated cells that migrate from the niche to perform specialized functions. The presence of proteins at the cell surface is often used to identify, classify, and isolate stem cells. Among the diverse groups of cell surface proteins used for these purposes, integrin α6, also known as CD49f, may be the only biomarker commonly found in more than 30 different populations of stem cells, including some cancer stem cells. This broad expression among stem cell populations indicates that integrin α6 may play an important and conserved role in stem cell biology, which is reaffirmed by recent demonstrations of its role maintaining self-renewal of pluripotent stem cells and breast and glioblastoma cancer stem cells. Therefore, this review intends to highlight and synthesize new findings on the importance of integrin α6 in stem cell biology.

  19. 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.

  20. Integrin beta 4 MRNA expression levels in bronchial asthma patients ...

    African Journals Online (AJOL)

    Egyptian Journal of Biochemistry and Molecular Biology. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 35, No 1-2 (2017) >. Log in or Register to get access to full text downloads.

  1. 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 ...

  2. 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

  3. Protein level affects the relative lysine requirement of growing rainbow trout (Oncorhynchus mykiss) fry.

    Science.gov (United States)

    Bodin, Noelie; Govaerts, Bernadette; Abboudi, Tarik; Detavernier, Christel; De Saeger, Sarah; Larondelle, Yvan; Rollin, Xavier

    2009-07-01

    The effect of two digestible protein levels (310 and 469 g/kg DM) on the relative lysine (Lys; g Lys/kg DM or g Lys/100 g protein) and the absolute Lys (g Lys intake/kg 0.75 per d) requirements was studied in rainbow trout fry using a dose-response trial. At each protein level, sixteen isoenergetic (22-23 MJ digestible energy/kg DM) diets were tested, involving a full range (2-70 g/kg DM) of sixteen Lys levels. Each diet was given to one group of sixty rainbow trout fry (mean initial body weight 0.78 g) reared at 15 degrees C for 31 feeding d. The Lys requirements were estimated based on the relationships between weight, protein, and Lys gains (g/kg 0.75 per d) and Lys concentration (g/kg DM or g/100 g protein) or Lys intake (g/kg 0.75 per d), using the broken-line model (BLM) and the non-linear four-parameter saturation kinetics model (SKM-4). Both the model and the response criterion chosen markedly impacted the relative Lys requirement. The relative Lys requirement for Lys gain of rainbow trout estimated with the BLM (and SKM-4 at 90 % of the maximum response) increased from 16.8 (19.6) g/kg DM at a low protein level to 23.4 (24.5) g/kg DM at a high protein level. However, the dietary protein content affected neither the absolute Lys requirement nor the relative Lys requirement expressed as g Lys/100 g protein nor the Lys requirement for maintenance (21 mg Lys/kg 0.75 per d).

  4. Integrative analysis of RNA, translation, and protein levels reveals distinct regulatory variation across humans.

    Science.gov (United States)

    Cenik, Can; Cenik, Elif Sarinay; Byeon, Gun W; Grubert, Fabian; Candille, Sophie I; Spacek, Damek; Alsallakh, Bilal; Tilgner, Hagen; Araya, Carlos L; Tang, Hua; Ricci, Emiliano; Snyder, Michael P

    2015-11-01

    Elucidating the consequences of genetic differences between humans is essential for understanding phenotypic diversity and personalized medicine. Although variation in RNA levels, transcription factor binding, and chromatin have been explored, little is known about global variation in translation and its genetic determinants. We used ribosome profiling, RNA sequencing, and mass spectrometry to perform an integrated analysis in lymphoblastoid cell lines from a diverse group of individuals. We find significant differences in RNA, translation, and protein levels suggesting diverse mechanisms of personalized gene expression control. Combined analysis of RNA expression and ribosome occupancy improves the identification of individual protein level differences. Finally, we identify genetic differences that specifically modulate ribosome occupancy--many of these differences lie close to start codons and upstream ORFs. Our results reveal a new level of gene expression variation among humans and indicate that genetic variants can cause changes in protein levels through effects on translation. © 2015 Cenik et al.; Published by Cold Spring Harbor Laboratory Press.

  5. Heightened systemic levels of neutrophil and eosinophil granular proteins in pulmonary tuberculosis and reversal following treatment.

    Science.gov (United States)

    Moideen, Kadar; Kumar, Nathella Pavan; Nair, Dina; Banurekha, Vaithilingam V; Bethunaickan, Ramalingam; Babu, Subash

    2018-04-09

    Granulocytes are activated during tuberculosis (TB) infection and act as immune effector cells and granulocyte responses are implicated in TB pathogenesis. Plasma levels of neutrophil and eosinophil granular proteins provide an indirect measure of degranulation. In this study, we wanted to examine the levels of neutrophil and eosinophil granular proteins in individuals with pulmonary tuberculosis (PTB) and to compare them with the levels in latent TB (LTB) individuals. Hence, we measured the plasma levels of myeloperoxidase (MPO), neutrophil elastase, and proteinase-3; major basic protein (MBP), eosinophil derived neurotoxin (EDN), eosinophil cationic protein (ECP) and eosinophil peroxidase (EPX) in these individuals. Finally, we also measured the levels of all of these parameters in PTB individuals following anti-tuberculosis (ATT) treatment. Our data reveal that PTB individuals are characterized by significantly higher plasma levels of MPO, elastase, human proteinase 3 as well as MBP and EDN in comparison to LTB individuals. Our data also reveal that ATT resulted in reversal of all of these changes, indicating an association with TB disease. Finally, our data show that the systemic levels of MPO and proteinase-3 can significantly discriminate PTB from LTB individuals. Thus, our data suggest that neutrophil and eosinophil granular proteins could play a potential role in the innate immune response and therefore, the pathogenesis of pulmonary TB. Copyright © 2018 American Society for Microbiology.

  6. Blocking immunosuppression by human Tregs in vivo with antibodies targeting integrin αVβ8.

    Science.gov (United States)

    Stockis, Julie; Liénart, Stéphanie; Colau, Didier; Collignon, Amandine; Nishimura, Stephen L; Sheppard, Dean; Coulie, Pierre G; Lucas, Sophie

    2017-11-21

    Human regulatory T cells (Tregs) suppress other T cells by converting the latent, inactive form of TGF-β1 into active TGF-β1. In Tregs, TGF-β1 activation requires GARP, a transmembrane protein that binds and presents latent TGF-β1 on the surface of Tregs stimulated through their T cell receptor. However, GARP is not sufficient because transduction of GARP in non-Treg T cells does not induce active TGF-β1 production. RGD-binding integrins were shown to activate TGF-β1 in several non-T cell types. Here we show that αVβ8 dimers are present on stimulated human Tregs but not in other T cells, and that antibodies against αV or β8 subunits block TGF-β1 activation in vitro. We also show that αV and β8 interact with GARP/latent TGF-β1 complexes in human Tregs. Finally, a blocking antibody against β8 inhibited immunosuppression by human Tregs in a model of xenogeneic graft-vs.-host disease induced by the transfer of human T cells in immunodeficient mice. These results show that TGF-β1 activation on the surface of human Tregs implies an interaction between the integrin αVβ8 and GARP/latent TGF-β1 complexes. Immunosuppression by human Tregs can be inhibited by antibodies against GARP or against the integrin β8 subunit. Such antibodies may prove beneficial against cancer or chronic infections.

  7. The Rho-family GTPase Rac1 regulates integrin localization in Drosophila immunosurveillance cells.

    Directory of Open Access Journals (Sweden)

    Miguel J Xavier

    Full Text Available BACKGROUND: When the parasitoid wasp Leptopilina boulardi lays an egg in a Drosophila larva, phagocytic cells called plasmatocytes and specialized cells known as lamellocytes encapsulate the egg. The Drosophila β-integrin Myospheroid (Mys is necessary for lamellocytes to adhere to the cellular capsule surrounding L. boulardi eggs. Integrins are heterodimeric adhesion receptors consisting of α and β subunits, and similar to other plasma membrane receptors undergo ligand-dependent endocytosis. In mammalian cells it is known that integrin binding to the extracellular matrix induces the activation of Rac GTPases, and we have previously shown that Rac1 and Rac2 are necessary for a proper encapsulation response in Drosophila larvae. We wanted to test the possibility that Myospheroid and Rac GTPases interact during the Drosophila anti-parasitoid immune response. RESULTS: In the current study we demonstrate that Rac1 is required for the proper localization of Myospheroid to the cell periphery of haemocytes after parasitization. Interestingly, the mislocalization of Myospheroid in Rac1 mutants is rescued by hyperthermia, involving the heat shock protein Hsp83. From these results we conclude that Rac1 and Hsp83 are required for the proper localization of Mys after parasitization. SIGNIFICANCE: We show for the first time that the small GTPase Rac1 is required for Mysopheroid localization. Interestingly, the necessity of Rac1 in Mys localization was negated by hyperthermia. This presents a problem, in Drosophila we quite often raise larvae at 29°C when using the GAL4/UAS misexpression system. If hyperthermia rescues receptor endosomal recycling defects, raising larvae in hyperthermic conditions may mask potentially interesting phenotypes.

  8. Changes in human parotid salivary protein and sialic acid levels during pregnancy.

    Science.gov (United States)

    D'Alessandro, S; Curbelo, H M; Tumilasci, O R; Tessler, J A; Houssay, A B

    1989-01-01

    Saliva was collected with a Carlson-Crittenden device, under citric acid stimulation, in 107 pregnant women, 9 puerperal and 7 non-pregnant controls. No significant changes were found in salivary flow rate, pH and amylase levels. The total protein levels were decreased during pregnancy and the puerperium. The sialic acid levels decreased gradually but markedly during pregnancy, returning to normal levels in the puerperium. These changes in parotid saliva may be related to the hormonal changes of pregnancy.

  9. Activated Integrin-Linked Kinase Negatively Regulates Muscle Cell Enhancement Factor 2C in C2C12 Cells

    Directory of Open Access Journals (Sweden)

    Zhenguo Dong

    2015-01-01

    Full Text Available Our previous study reported that muscle cell enhancement factor 2C (MEF2C was fully activated after inhibition of the phosphorylation activity of integrin-linked kinase (ILK in the skeletal muscle cells of goats. It enhanced the binding of promoter or enhancer of transcription factor related to proliferation of muscle cells and then regulated the expression of these genes. In the present investigation, we explored whether ILK activation depended on PI3K to regulate the phosphorylation and transcriptional activity of MEF2C during C2C12 cell proliferation. We inhibited PI3K activity in C2C12 with LY294002 and then found that ILK phosphorylation levels and MEF2C phosphorylation were decreased and that MCK mRNA expression was suppressed significantly. After inhibiting ILK phosphorylation activity with Cpd22 and ILK-shRNA, we found MEF2C phosphorylation activity and MCK mRNA expression were increased extremely significantly. In the presence of Cpd22, PI3K activity inhibition increased MEF2C phosphorylation and MCK mRNA expression indistinctively. We conclude that ILK negatively and independently of PI3K regulated MEF2C phosphorylation activity and MCK mRNA expression in C2C12 cells. The results provide new ideas for the study of classical signaling pathway of PI3K-ILK-related proteins and transcription factors.

  10. 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.

  11. Fasting Lipoprotein Lipase Protein Levels Can Predict a Postmeal Increment of Triglyceride Levels in Fasting Normohypertriglyceridemic Subjects.

    Science.gov (United States)

    Tsuzaki, Kokoro; Kotani, Kazuhiko; Yamada, Kazunori; Sakane, Naoki

    2016-09-01

    Although a postprandial increment in triglyceride (TG) levels is considered to be a risk factor for atherogenesis, tests (e.g., fat load) to assess postprandial changes in TG levels cannot be easily applied to clinical practice. Therefore, fasting markers that predict postprandial TG states are needed to be developed. One current candidate is lipoprotein lipase (LPL) protein, a molecule that hydrides TGs. This study investigated whether fasting LPL levels could predict postprandial TG levels. A total of 17 subjects (11 men, 6 women, mean age 52 ± 11 years) with normotriglyceridemia during fasting underwent the meal test. Several fasting parameters, including LPL, were measured for the area under the curve of postprandial TGs (AUC-TG). The subjects' mean fasting TG level was 1.30 mmol/l, and their mean LPL level was 41.6 ng/ml. The subjects' TG levels increased after loading (they peaked after two postprandial hours). Stepwise multiple regression analysis demonstrated that fasting TG levels were a predictor of the AUC-TG. In addition, fasting LPL mass levels were found to be a predictor of the AUC-TG (β = 0.65, P fasting TG levels. Fasting LPL levels may be useful to predict postprandial TG increment in this population. © 2015 Wiley Periodicals, Inc.

  12. Performance of juvenile mojarra supplied with feed containing varying levels of crude protein

    Directory of Open Access Journals (Sweden)

    Ricardo Henrique Bastos de Souza

    2016-04-01

    Full Text Available ABSTRACT The growth of the Brazilian aquaculture has stimulated the development of the productive chain of native species, including marine environment. The objective of this study was to evaluate the growth performance of juvenile mojarra fish (Diapterus rhombeus fed diets containing different concentrations of crude protein (32, 36, 40 and 44 g 100 g-1. The 80 juvenile mojarra (7.2±1.5 g were kept in 16 circular tanks (150 L. The study design used was completely randomized with four treatments and four repetitions. The fish were fed four times a day. At the end of the experiment (60 days the final weight, feed intake, weight gain (WG, feed:gain ratio (FGR, protein efficiency rate (PER, energy efficiency rate, specific growth, survival rate and, body composition were evaluated. It was verified significant effect of protein level on the WG, with the best value at the level of 38.20 g 100 g-1 of crude protein. For FGR, the best estimated value occurred with 38.06 g 100 g-1 of crude protein, similar to that reported for the PER (38.91 g 100 g-1. The other performance parameters and body composition were not influenced by crude protein levels. Diet crude protein concentrations between 38.06 and 38.91 g 100 g-1 provide the best performance indices for juvenile mojarra.

  13. Exploring sequence characteristics related to high-level production of secreted proteins in Aspergillus niger.

    Directory of Open Access Journals (Sweden)

    Bastiaan A van den Berg

    Full Text Available Protein sequence features are explored in relation to the production of over-expressed extracellular proteins by fungi. Knowledge on features influencing protein production and secretion could be employed to improve enzyme production levels in industrial bioprocesses via protein engineering. A large set, over 600 homologous and nearly 2,000 heterologous fungal genes, were overexpressed in Aspergillus niger using a standardized expression cassette and scored for high versus no production. Subsequently, sequence-based machine learning techniques were applied for identifying relevant DNA and protein sequence features. The amino-acid composition of the protein sequence was found to be most predictive and interpretation revealed that, for both homologous and heterologous gene expression, the same features are important: tyrosine and asparagine composition was found to have a positive correlation with high-level production, whereas for unsuccessful production, contributions were found for methionine and lysine composition. The predictor is available online at http://bioinformatics.tudelft.nl/hipsec. Subsequent work aims at validating these findings by protein engineering as a method for increasing expression levels per gene copy.

  14. Specific Increase of Protein Levels by Enhancing Translation Using Antisense Oligonucleotides Targeting Upstream Open Frames.

    Science.gov (United States)

    Liang, Xue-Hai; Shen, Wen; Crooke, Stanley T

    2017-01-01

    A number of diseases are caused by low levels of key proteins; therefore, increasing the amount of specific proteins in human bodies is of therapeutic interest. Protein expression is downregulated by some structural or sequence elements present in the 5' UTR of mRNAs, such as upstream open reading frames (uORF). Translation initiation from uORF(s) reduces translation from the downstream primary ORF encoding the main protein product in the same mRNA, leading to a less efficient protein expression. Therefore, it is possible to use antisense oligonucleotides (ASOs) to specifically inhibit translation of the uORF by base-pairing with the uAUG region of the mRNA, redirecting translation machinery to initiate from the primary AUG site. Here we review the recent findings that translation of specific mRNAs can be enhanced using ASOs targeting uORF regions. Appropriately designed and optimized ASOs are highly specific, and they act in a sequence- and position-dependent manner, with very minor off-target effects. Protein levels can be increased using this approach in different types of human and mouse cells, and, importantly, also in mice. Since uORFs are present in around half of human mRNAs, the uORF-targeting ASOs may thus have valuable potential as research tools and as therapeutics to increase the levels of proteins for a variety of genes.

  15. Alcohol-Binding Sites in Distinct Brain Proteins: The Quest for Atomic Level Resolution

    Science.gov (United States)

    Howard, Rebecca J.; Slesinger, Paul A.; Davies, Daryl L.; Das, Joydip; Trudell, James R.; Harris, R. Adron

    2011-01-01

    Defining the sites of action of ethanol on brain proteins is a major prerequisite to understanding the molecular pharmacology of this drug. The main barrier to reaching an atomic-level understanding of alcohol action is the low potency of alcohols, ethanol in particular, which is a reflection of transient, low-affinity interactions with their targets. These mechanisms are difficult or impossible to study with traditional techniques such as radioligand binding or spectroscopy. However, there has been considerable recent progress in combining X-ray crystallography, structural modeling, and site-directed mutagenesis to define the sites and mechanisms of action of ethanol and related alcohols on key brain proteins. We review such insights for several diverse classes of proteins including inwardly rectifying potassium, transient receptor potential, and neurotransmit-ter-gated ion channels, as well as protein kinase C epsilon. Some common themes are beginning to emerge from these proteins, including hydrogen bonding of the hydroxyl group and van der Waals interactions of the methylene groups of ethanol with specific amino acid residues. The resulting binding energy is proposed to facilitate or stabilize low-energy state transitions in the bound proteins, allowing ethanol to act as a “molecular lubricant” for protein function. We discuss evidence for characteristic, discrete alcohol-binding sites on protein targets, as well as evidence that binding to some proteins is better characterized by an interaction region that can accommodate multiple molecules of ethanol. PMID:21676006

  16. 2-Oxoglutarate levels control adenosine nucleotide binding by Herbaspirillum seropedicae PII proteins.

    Science.gov (United States)

    Oliveira, Marco A S; Gerhardt, Edileusa C M; Huergo, Luciano F; Souza, Emanuel M; Pedrosa, Fábio O; Chubatsu, Leda S

    2015-12-01

    Nitrogen metabolism in Proteobacteria is controlled by the Ntr system, in which PII proteins play a pivotal role, controlling the activity of target proteins in response to the metabolic state of the cell. Characterization of the binding of molecular effectors to these proteins can provide information about their regulation. Here, the binding of ATP, ADP and 2-oxoglutarate (2-OG) to the Herbaspirillum seropedicae PII proteins, GlnB and GlnK, was characterized using isothermal titration calorimetry. Results show that these proteins can bind three molecules of ATP, ADP and 2-OG with homotropic negative cooperativity, and 2-OG binding stabilizes the binding of ATP. Results also show that the affinity of uridylylated forms of GlnB and GlnK for nucleotides is significantly lower than that of the nonuridylylated proteins. Furthermore, fluctuations in the intracellular concentration of 2-OG in response to nitrogen availability are shown. Results suggest that under nitrogen-limiting conditions, PII proteins tend to bind ATP and 2-OG. By contrast, after an ammonium shock, a decrease in the 2-OG concentration is observed causing a decrease in the affinity of PII proteins for ATP. This phenomenon may facilitate the exchange of ATP for ADP on the ligand-binding pocket of PII proteins, thus it is likely that under low ammonium, low 2-OG levels would favor the ADP-bound state. © 2015 FEBS.

  17. Multi-level machine learning prediction of protein–protein interactions in Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    Julian Zubek

    2015-07-01

    Full Text Available Accurate identification of protein–protein interactions (PPI is the key step in understanding proteins’ biological functions, which are typically context-dependent. Many existing PPI predictors rely on aggregated features from protein sequences, however only a few methods exploit local information about specific residue contacts. In this work we present a two-stage machine learning approach for prediction of protein–protein interactions. We start with the carefully filtered data on protein complexes available for Saccharomyces cerevisiae in the Protein Data Bank (PDB database. First, we build linear descriptions of interacting and non-interacting sequence segment pairs based on their inter-residue distances. Secondly, we train machine learning classifiers to predict binary segment interactions for any two short sequence fragments. The final prediction of the protein–protein interaction is done using the 2D matrix representation of all-against-all possible interacting sequence segments of both analysed proteins. The level-I predictor achieves 0.88 AUC for micro-scale, i.e., residue-level prediction. The level-II predictor improves the results further by a more complex learning paradigm. We perform 30-fold macro-scale, i.e., protein-level cross-validation experiment. The level-II predictor using PSIPRED-predicted secondary structure reaches 0.70 precision, 0.68 recall, and 0.70 AUC, whereas other popular methods provide results below 0.6 threshold (recall, precision, AUC. Our results demonstrate that multi-scale sequence features aggregation procedure is able to improve the machine learning results by more than 10% as compared to other sequence representations. Prepared datasets and source code for our experimental pipeline are freely available for download from: http://zubekj.github.io/mlppi/ (open source Python implementation, OS independent.

  18. Level of C - reactive protein as an indicator for prognosis of premature uterine contractions.

    Science.gov (United States)

    Najat Nakishbandy, Bayar M; Barawi, Sabat A M

    2014-01-01

    high concentrations of maternal C-reactive protein have been associated with adverse pregnancy outcome, and premature uterine contraction may be predicted by elevated levels of C-reactive protein. This may ultimately be simple and cost-effective enough to introduce as a low-risk screening program. an observational case control study was performed from May 1st, 2010 to December 1st, 2010 at Maternity Teaching Hospital-Erbil/ Kurdistan Region/ Iraq. The sample size was (200) cases. Hundred of them were presented with premature uterine contractions at 24(+0)-36(+6) weeks. The other hundred were control group at same gestational ages. The level of C-reactive protein was determined in both groups and both groups were followed till delivery. (93) out of (100) women with premature uterine contractions had elevated level of C-Reactive protein and 91% delivered prematurely while in the control group only (9) out of (100) women had elevated level of C-reactive protein and only 8% of them delivered preterm. Differences were statistically highly significant. C-reactive protein can be used as a biomarker in prediction of premature delivery when it is associated with premature uterine contractions. As well it can be used as a screening test to detect cases that are at risk of premature delivery.

  19. 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.

  20. Harmful effect of protein difficiency on lipids, glucose, insulin and estradiol levels in female albino rats

    International Nuclear Information System (INIS)

    El-Mahdy, A.A.; El-Sherbiny, E.M.; Bayomi, M.M.

    2005-01-01

    The present study was undertaken to investigate the harmful effect of protein deficient diet on some biochemical activities in serum of female rats. Protein malnutrition is a well known socioeconomic problem in different parts of the world. Many studies were investigated on the biological parameters following protein malnutrition in human and experimental animals. Forty albino female rats were divided into 3 groups. The first group (10 rats) fed 18% protein diet and served as normal control and the other two groups, each contains 15 rats, fed 5% protein for 21 and 45 days, respectively, and served as malnourished groups. The results showed significant decrease in total body weight, serum glucose, insulin and estradiol levels in the third group as well as decrease in the total cholesterol, HDL-cholesterol, LDL-cholesterol and VLDL-cholesterol and triglycerides concentrations that compared to normal control rats

  1. Protein Consumption and the Elderly: What Is the Optimal Level of Intake?

    Directory of Open Access Journals (Sweden)

    Jamie I. Baum

    2016-06-01

    Full Text Available Maintaining independence, quality of life, and health is crucial for elderly adults. One of the major threats to living independently is the loss of muscle mass, strength, and function that progressively occurs with aging, known as sarcopenia. Several studies have identified protein (especially the essential amino acids as a key nutrient for muscle health in elderly adults. Elderly adults are less responsive to the anabolic stimulus of low doses of amino acid intake compared to younger individuals. However, this lack of responsiveness in elderly adults can be overcome with higher levels of protein (or essential amino acid consumption. The requirement for a larger dose of protein to generate responses in elderly adults similar to the responses in younger adults provides the support for a beneficial effect of increased protein in older populations. The purpose of this review is to present the current evidence related to dietary protein intake and muscle health in elderly adults.

  2. Predicting protein folding rate change upon point mutation using residue-level coevolutionary information.

    Science.gov (United States)

    Mallik, Saurav; Das, Smita; Kundu, Sudip

    2016-01-01

    Change in folding kinetics of globular proteins upon point mutation is crucial to a wide spectrum of biological research, such as protein misfolding, toxicity, and aggregations. Here we seek to address whether residue-level coevolutionary information of globular proteins can be informative to folding rate changes upon point mutations. Generating residue-level coevolutionary networks of globular proteins, we analyze three parameters: relative coevolution order (rCEO), network density (ND), and characteristic path length (CPL). A point mutation is considered to be equivalent to a node deletion of this network and respective percentage changes in rCEO, ND, CPL are found linearly correlated (0.84, 0.73, and -0.61, respectively) with experimental folding rate changes. The three parameters predict the folding rate change upon a point mutation with 0.031, 0.045, and 0.059 standard errors, respectively. © 2015 Wiley Periodicals, Inc.

  3. Evidence of G-protein-coupled receptor and substrate transporter heteromerization at a single molecule level.

    Science.gov (United States)

    Fischer, Jana; Kleinau, Gunnar; Rutz, Claudia; Zwanziger, Denise; Khajavi, Noushafarin; Müller, Anne; Rehders, Maren; Brix, Klaudia; Worth, Catherine L; Führer, Dagmar; Krude, Heiko; Wiesner, Burkhard; Schülein, Ralf; Biebermann, Heike

    2018-06-01

    G-protein-coupled receptors (GPCRs) can constitute complexes with non-GPCR integral membrane proteins, while such interaction has not been demonstrated at a single molecule level so far. We here investigated the potential interaction between the thyrotropin receptor (TSHR) and the monocarboxylate transporter 8 (MCT8), a member of the major facilitator superfamily (MFS), using fluorescence cross-correlation spectroscopy (FCCS). Both the proteins are expressed endogenously on the basolateral plasma membrane of the thyrocytes and are involved in stimulation of thyroid hormone production and release. Indeed, we demonstrate strong interaction between both the proteins which causes a suppressed activation of G q/11 by TSH-stimulated TSHR. Thus, we provide not only evidence for a novel interaction between the TSHR and MCT8, but could also prove this interaction on a single molecule level. Moreover, this interaction forces biased signaling at the TSHR. These results are of general interest for both the GPCR and the MFS research fields.

  4. Protein synthesis levels are increased in a subset of individuals with Fragile X syndrome

    DEFF Research Database (Denmark)

    Jacquemont, Sébastien; Pacini, Laura; Jønch, Aia E

    2018-01-01

    architecture and plasticity. Preclinical studies revealed that pharmacological interventions restore those deficits, which are thought to mediate the FXS cognitive and behavioral symptoms. Here we characterized the de novo rate of protein synthesis in patients with FXS and their relationship with clinical...... severity. We measured the rate of protein synthesis in fibroblasts derived from 32 individuals with FXS and from 17 controls as well as in fibroblasts and primary neurons of 27 Fmr1 KO mice and 20 controls. Here we show that levels of protein synthesis are increased in fibroblasts of individuals with FXS...... and Fmr1 KO mice. However, this cellular phenotype displays a broad distribution and a proportion of fragile X individuals and Fmr1 KO mice do not show increased levels of protein synthesis, having measures in the normal range. Because the same Fmr1 KO animal measures in fibroblasts predict those...

  5. 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...

  6. Do infants with cow's milk protein allergy have inadequate levels of vitamin D?

    Science.gov (United States)

    Silva, Cristiane M; Silva, Silvia A da; Antunes, Margarida M de C; Silva, Gisélia Alves Pontes da; Sarinho, Emanuel Sávio Cavalcanti; Brandt, Katia G

    To verify whether infants with cow's milk protein allergy have inadequate vitamin D levels. This cross-sectional study included 120 children aged 2 years or younger, one group with cow's milk protein allergy and a control group. The children were recruited at the pediatric gastroenterology, allergology, and pediatric outpatient clinics of a university hospital in the Northeast of Brazil. A questionnaire was administered to the caregiver and blood samples were collected for vitamin D quantification. Vitamin D levels <30ng/mL were considered inadequate. Vitamin D level was expressed as mean and standard deviation, and the frequency of the degrees of sufficiency and other variables, as proportions. Infants with cow's milk protein allergy had lower mean vitamin D levels (30.93 vs.35.29ng/mL; p=0.041) and higher deficiency frequency (20.3% vs.8.2; p=0.049) than the healthy controls. Exclusively or predominantly breastfed infants with cow's milk protein allergy had higher frequency of inadequate vitamin D levels (p=0.002). Regardless of sun exposure time, the groups had similar frequencies of inadequate vitamin D levels (p=0.972). Lower vitamin D levels were found in infants with CMPA, especially those who were exclusively or predominantly breastfed, making these infants a possible risk group for vitamin D deficiency. Copyright © 2017 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

  7. Do infants with cow's milk protein allergy have inadequate levels of vitamin D?

    Directory of Open Access Journals (Sweden)

    Cristiane M. Silva

    Full Text Available Abstract Objective: To verify whether infants with cow's milk protein allergy have inadequate vitamin D levels. Methods: This cross-sectional study included 120 children aged 2 years or younger, one group with cow's milk protein allergy and a control group. The children were recruited at the pediatric gastroenterology, allergology, and pediatric outpatient clinics of a university hospital in the Northeast of Brazil. A questionnaire was administered to the caregiver and blood samples were collected for vitamin D quantification. Vitamin D levels <30 ng/mL were considered inadequate. Vitamin D level was expressed as mean and standard deviation, and the frequency of the degrees of sufficiency and other variables, as proportions. Results: Infants with cow's milk protein allergy had lower mean vitamin D levels (30.93 vs.35.29 ng/mL; p = 0.041 and higher deficiency frequency (20.3% vs.8.2; p = 0.049 than the healthy controls. Exclusively or predominantly breastfed infants with cow's milk protein allergy had higher frequency of inadequate vitamin D levels (p = 0.002. Regardless of sun exposure time, the groups had similar frequencies of inadequate vitamin D levels (p = 0.972. Conclusions: Lower vitamin D levels were found in infants with CMPA, especially those who were exclusively or predominantly breastfed, making these infants a possible risk group for vitamin D deficiency.

  8. Less is More: Membrane Protein Digestion Beyond Urea-Trypsin Solution for Next-level Proteomics.

    Science.gov (United States)

    Zhang, Xi

    2015-09-01

    The goal of next-level bottom-up membrane proteomics is protein function investigation, via high-coverage high-throughput peptide-centric quantitation of expression, modifications and dynamic structures at systems scale. Yet efficient digestion of mammalian membrane proteins presents a daunting barrier, and prevalent day-long urea-trypsin in-solution digestion proved insufficient to reach this goal. Many efforts contributed incremental advances over past years, but involved protein denaturation that disconnected measurement from functional states. Beyond denaturation, the recent discovery of structure/proteomics omni-compatible detergent n-dodecyl-β-d-maltopyranoside, combined with pepsin and PNGase F columns, enabled breakthroughs in membrane protein digestion: a 2010 DDM-low-TCEP (DLT) method for H/D-exchange (HDX) using human G protein-coupled receptor, and a 2015 flow/detergent-facilitated protease and de-PTM digestions (FDD) for integrative deep sequencing and quantitation using full-length human ion channel complex. Distinguishing protein solubilization from denaturation, protease digestion reliability from theoretical specificity, and reduction from alkylation, these methods shifted day(s)-long paradigms into minutes, and afforded fully automatable (HDX)-protein-peptide-(tandem mass tag)-HPLC pipelines to instantly measure functional proteins at deep coverage, high peptide reproducibility, low artifacts and minimal leakage. Promoting-not destroying-structures and activities harnessed membrane proteins for the next-level streamlined functional proteomics. This review analyzes recent advances in membrane protein digestion methods and highlights critical discoveries for future proteomics. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  9. BDNF downregulates 5-HT(2A) receptor protein levels in hippocampal cultures

    DEFF Research Database (Denmark)

    Trajkovska, V; Santini, M A; Marcussen, Anders Bue

    2009-01-01

    Both brain-derived neurotrophic factor (BDNF) and the serotonin receptor 2A (5-HT(2A)) have been related to depression pathology. Specific 5-HT(2A) receptor changes seen in BDNF conditional mutant mice suggest that BDNF regulates the 5-HT(2A) receptor level. Here we show a direct effect of BDNF...... on 5-HT(2A) receptor protein levels in primary hippocampal neuronal and mature hippocampal organotypic cultures exposed to different BDNF concentrations for either 1, 3, 5 or 7 days. In vivo effects of BDNF on hippocampal 5-HT(2A) receptor levels were further corroborated in (BDNF +/-) mice...... with reduced BDNF levels. In primary neuronal cultures, 7 days exposure to 25 and 50ng/mL BDNF resulted in downregulation of 5-HT(2A), but not of 5-HT(1A), receptor protein levels. The BDNF-associated downregulation of 5-HT(2A) receptor levels was also observed in mature hippocampal organotypic cultures...

  10. Investigation of the molecular level interactions between mucins and food proteins: Spectroscopic, tribological and rheological studies

    OpenAIRE

    Celebioglu, Hilal Yilmaz; Chronakis, Ioannis S.; Lee, Seunghwan; Guðjónsdóttir, María

    2017-01-01

    The thesis investigated the structure and molecular-level interaction of β-lactoglobulin (BLG) and mucins, representing major components of the dairy products and saliva/digestion systems, respectively. Mucins are long glycoprotein molecules responsible for the gel nature of the mucous layer covers epithelial surfaces throughout the body. A literature review of the interactions of different mucin types and saliva mucins with several food proteins and food protein emulsions, as well as their f...

  11. Urea metabolism in buffalo calves fed on rations containing two levels of crude protein

    International Nuclear Information System (INIS)

    Verma, D.N.; Singh, U.B.; Lal, M.; Varma, A.; Ranjhan, S.K.

    1974-01-01

    Urea entry rates into the body pools of Murrah Buffalo calves have been estimated using a single injection isotope dilution technique using 14 C-urea. The animals were fed two levels of crude proteins, namely, 13 percent lower and 19 percent higher than N.R.C. recommendations. Results show that the recycling of urea is significantly better in animals given low crude protein contents. (M.G.B.)

  12. Effects of dietary protein levels on length-weight relationships and ...

    African Journals Online (AJOL)

    Feeding trial involving different protein levels on length–weight relationships and condition factor of Clarias gariepinus was conducted in floating hapa system. Fingerlings (average weight, 4.50± 0.01g and average length, 8.0±0.2 cm) were randomly stocked at 20 fish/1m3. Five diets with crude protein: 40.0, 42.5, 45.0, 47.5 ...

  13. Interaction betwen Lead and Bone Protein to Affect Bone Calcium Level Using UV-Vis Spectroscopy

    Science.gov (United States)

    Noor, Z.; Azharuddin, A.; Aflanie, I.; Kania, N.; Suhartono, E.

    2018-05-01

    This present study aim to evaluate the interactions between lead (Pb) and with bone protein by UV-Vis approach. In addition, this prsent study also aim to investigate the effect of Pb on bone calcium (Ca) level. The present study was a true experimental study design to examine the impact of Pb exposure in bone of male rats (Rattus novergicus). The study involved 5 groups, P1 was the control group, while the other (P2-P5) were the case group with exposure of Pb in different concentration within 4 weeks. At the end of the exposure, the interaction between Pb and protein was determined using UV-Vis spectrophotometric method, and the Ca level was determined using permanganometric method. The results shows that that there is an interaction between Pb and bone protein. The result also shows that the value of the binding constant of Protein-Pb is 32.71. It means Pb have an high affinity to bind with bone protein, which promote a further reaction to induced the release of bone Ca from the bone protein. In conclusion, this present study found an obvious relationship between Pb and bone protein which promote a further reaction to increase the releasing of bone calcium.

  14. Denaturing high-performance liquid chromatography mutation analysis in patients with reduced Protein S levels

    DEFF Research Database (Denmark)

    Bathum, Lise; Münster, Anna-Marie; Nybo, Mads

    2008-01-01

    diagnosis and risk estimation. The aim was to design a high-throughput genetic analysis based on denaturing high-performance liquid chromatography to identify sequence variations in the gene coding for Protein S. PATIENTS: In total, 55 patients referred to the Section of Thrombosis and Haemostasis, Odense......BACKGROUND: Patients with congenital Protein S deficiency have increased risk of venous thromboembolism. However, Protein S levels show large intra-individual variation and the biochemical assays have low accuracy and a high interlaboratory variability. Genetic analysis might aid in a more precise......, giving a precise diagnosis and subsequently a better risk estimation....

  15. Serum eosinophil cationic protein levels can be useful for predicting acute exacerbation of asthma

    Directory of Open Access Journals (Sweden)

    Mitsuhiro Kamimura

    1998-01-01

    Full Text Available We report on a case in which five consecutive exacerbations of asthma were monitored by following serum eosinophil cationic protein (ECP levels. The serum ECP level correlated well with each exacerbation and tended to increase even before the exacerbations of asthma became apparent. This case shows that serum levels of ECP can be useful markers of disease activity and may also be predictive markers for acute exacerbation.

  16. Evolutionary tuning of protein expression levels of a positively autoregulated two-component system.

    Directory of Open Access Journals (Sweden)

    Rong Gao

    2013-10-01

    Full Text Available Cellular adaptation relies on the development of proper regulatory schemes for accurate control of gene expression levels in response to environmental cues. Over- or under-expression can lead to diminished cell fitness due to increased costs or insufficient benefits. Positive autoregulation is a common regulatory scheme that controls protein expression levels and gives rise to essential features in diverse signaling systems, yet its roles in cell fitness are less understood. It remains largely unknown how much protein expression is 'appropriate' for optimal cell fitness under specific extracellular conditions and how the dynamic environment shapes the regulatory scheme to reach appropriate expression levels. Here, we investigate the correlation of cell fitness and output response with protein expression levels of the E. coli PhoB/PhoR two-component system (TCS. In response to phosphate (Pi-depletion, the PhoB/PhoR system activates genes involved in phosphorus assimilation as well as genes encoding themselves, similarly to many other positively autoregulated TCSs. We developed a bacteria competition assay in continuous cultures and discovered that different Pi conditions have conflicting requirements of protein expression levels for optimal cell fitness. Pi-replete conditions favored cells with low levels of PhoB/PhoR while Pi-deplete conditions selected for cells with high levels of PhoB/PhoR. These two levels matched PhoB/PhoR concentrations achieved via positive autoregulation in wild-type cells under Pi-replete and -deplete conditions, respectively. The fitness optimum correlates with the wild-type expression level, above which the phosphorylation output saturates, thus further increase in expression presumably provides no additional benefits. Laboratory evolution experiments further indicate that cells with non-ideal protein levels can evolve toward the optimal levels with diverse mutational strategies. Our results suggest that the natural

  17. Mechanically enforced bond dissociation reports synergistic influence of Mn2+ and Mg2+ on the interaction between integrin α7β1 and invasin

    DEFF Research Database (Denmark)

    Ligezowska, Agnieszka; Boye, Kristian; Eble, Johannes A.

    2011-01-01

    addition of these cations to the measurement buffer, we observe a pronounced increase in the force necessary to separate integrin and invasin coated beads. Both ions were found to work synergistically. With free invasin in the measurement buffer we furthermore observe that competitive blocking of binding...... sites overrides the increase in binding strength of individual beads. We show that this is due to a very strong dependence of bond affinity on divalent ions. Our study illustrates the importance of divalent ions for the regulation of force transmission by integrin ligand bonds on the molecular level...

  18. Urokinase-type plasminogen activator receptor (uPAR) ligation induces a raft-localized integrin signaling switch that mediates the hypermotile phenotype of fibrotic fibroblasts.

    Science.gov (United States)

    Grove, Lisa M; Southern, Brian D; Jin, Tong H; White, Kimberly E; Paruchuri, Sailaja; Harel, Efrat; Wei, Ying; Rahaman, Shaik O; Gladson, Candece L; Ding, Qiang; Craik, Charles S; Chapman, Harold A; Olman, Mitchell A

    2014-05-02

    The urokinase-type plasminogen activator receptor (uPAR) is a glycosylphosphatidylinositol-linked membrane protein with no cytosolic domain that localizes to lipid raft microdomains. Our laboratory and others have documented that lung fibroblasts from patients with idiopathic pulmonary fibrosis (IPF) exhibit a hypermotile phenotype. This study was undertaken to elucidate the molecular mechanism whereby uPAR ligation with its cognate ligand, urokinase, induces a motile phenotype in human lung fibroblasts. We found that uPAR ligation with the urokinase receptor binding domain (amino-terminal fragment) leads to enhanced migration of fibroblasts on fibronectin in a protease-independent, lipid raft-dependent manner. Ligation of uPAR with the amino-terminal fragment recruited α5β1 integrin and the acylated form of the Src family kinase, Fyn, to lipid rafts. The biological consequences of this translocation were an increase in fibroblast motility and a switch of the integrin-initiated signal pathway for migration away from the lipid raft-independent focal adhesion kinase pathway and toward a lipid raft-dependent caveolin-Fyn-Shc pathway. Furthermore, an integrin homologous peptide as well as an antibody that competes with β1 for uPAR binding have the ability to block this effect. In addition, its relative insensitivity to cholesterol depletion suggests that the interactions of α5β1 integrin and uPAR drive the translocation of α5β1 integrin-acylated Fyn signaling complexes into lipid rafts upon uPAR ligation through protein-protein interactions. This signal switch is a novel pathway leading to the hypermotile phenotype of IPF patient-derived fibroblasts, seen with uPAR ligation. This uPAR dependent, fibrotic matrix-selective, and profibrotic fibroblast phenotype may be amenable to targeted therapeutics designed to ameliorate IPF.

  19. 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...

  20. Ground level environmental protein concentrations in various ecuadorian environments: potential uses of aerosolized protein for ecological research

    Science.gov (United States)

    Staton, Sarah J.R.; Woodward, Andrea; Castillo, Josemar A.; Swing, Kelly; Hayes, Mark A.

    2014-01-01

    Large quantities of free protein in the environment and other bioaerosols are ubiquitous throughout terrestrial ground level environments and may be integrative indicators of ecosystem status. Samples of ground level bioaerosols were collected from various ecosystems throughout Ecuador, including pristine humid tropical forest (pristine), highly altered secondary humid tropical forest (highly altered), secondary transitional very humid forest (regrowth transitional), and suburban dry montane deforested (suburban deforested). The results explored the sensitivity of localized aerosol protein concentrations to spatial and temporal variations within ecosystems, and their value for assessing environmental change. Ecosystem specific variations in environmental protein concentrations were observed: pristine 0.32 ± 0.09 μg/m3, highly altered 0.07 ± 0.05 μg/m3, regrowth transitional 0.17 ± 0.06 μg/m3, and suburban deforested 0.09 ± 0.04 μg/m3. Additionally, comparisons of intra-environmental differences in seasonal/daily weather (dry season 0.08 ± 0.03 μg/m3 and wet season 0.10 ± 0.04 μg/m3), environmental fragmentation (buffered 0.19 ± 0.06 μg/m3 and edge 0.15 ± 0.06 μg/m3), and sampling height (ground level 0.32 ± 0.09 μg/m3 and 10 m 0.24 ± 0.04 μg/m3) demonstrated the sensitivity of protein concentrations to environmental conditions. Local protein concentrations in altered environments correlated well with satellite-based spectral indices describing vegetation productivity: normalized difference vegetation index (NDVI) (r2 = 0.801), net primary production (NPP) (r2 = 0.827), leaf area index (LAI) (r2 = 0.410). Moreover, protein concentrations distinguished the pristine site, which was not differentiated in spectral indices, potentially due to spectral saturation typical of highly vegetated environments. Bioaerosol concentrations represent an inexpensive method to increase understanding of environmental changes, especially in densely vegetated

  1. Developmental control of integrin expression regulates Th2 effector homing

    Science.gov (United States)

    Integrin CD18, a component of the LFA-1 complex that also includes CD11a, is essential for Th2, but not Th1, cell homing, but the explanation for this phenomenon remains obscure. In this study, we investigate the mechanism by which Th2 effector responses require the LFA-1 complex. CD11a-deficient T ...

  2. Integrins promote axonal regeneration after injury of the nervous system

    NARCIS (Netherlands)

    Nieuwenhuis, Bart; Haenzi, B.; Andrews, M.R.; Verhaagen, J.; Fawcett, J.W.

    2018-01-01

    Integrins are cell surface receptors that form the link between extracellular matrix molecules of the cell environment and internal cell signalling and the cytoskeleton. They are involved in several processes, e.g. adhesion and migration during development and repair. This review focuses on the role

  3. 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

  4. Beta 1 integrin is essential for teratoma growth and angiogenesis

    DEFF Research Database (Denmark)

    Bloch, W; Forsberg, E; Lentini, S

    1997-01-01

    Teratomas are benign tumors that form after ectopic injection of embryonic stem (ES) cells into mice and contain derivatives of all primitive germ layers. To study the role of beta 1 integrin during teratoma formation, we compared teratomas induced by normal and beta1-null ES cells. Injection of ...

  5. The strength of integrin binding between neutrophils and endothelial cells

    Czech Academy of Sciences Publication Activity Database

    Labrador, V.; Říha, Pavel; Muller, S.; Dumas, D.; Wang, X.; Stoltz, J. F.

    2003-01-01

    Roč. 32, č. 8 (2003), s. 684-688 ISSN 0175-7571 R&D Projects: GA ČR GA305/01/1605 Institutional research plan: CEZ:AV0Z2060917 Keywords : endothelium * integrins * neutrophil adhesion * scanning microscopy Subject RIV: BO - Biophysics Impact factor: 1.769, year: 2003

  6. Gene and process level modulation to overcome the bottlenecks of recombinant proteins expression in Pichia pastoris.

    Science.gov (United States)

    Prabhu, Ashish A; Boro, Bibari; Bharali, Biju; Chakraborty, Shuchishloka; Dasu, V Venkata

    2018-03-28

    Process development involving system metabolic engineering and bioprocess engineering has become one of the major thrust for the development of therapeutic proteins or enzymes. Pichia pastoris has emerged as a prominent host for the production of therapeutic protein or enzymes. Despite of producing high protein titers, various cellular and process level bottlenecks hinders the expression of recombinant proteins in P. pastoris. In the present review, we have summarized the recent developments in the expression of foreign proteins in P. pastoris. Further, we have discussed various cellular engineering strategies which include codon optimization, pathway engineering, signal peptide processing, development of protease deficient strain and glyco-engineered strains for the high yield protein secretion of recombinant protein. Bioprocess development of recombinant proteins in large scale bioreactor including medium optimization, optimum feeding strategy and co-substrate feeding in fed batch as well as continuous cultivation have been described. The recent advances in system and synthetic biology studies including metabolic flux analysis in understanding the phenotypic characteristics of recombinant Pichia and genome editing with CRISPR-CAS system have also been summarized. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  7. 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.

  8. 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.

  9. Noise genetics: inferring protein function by correlating phenotype with protein levels and localization in individual human cells.

    Directory of Open Access Journals (Sweden)

    Shlomit Farkash-Amar

    2014-03-01

    Full Text Available To understand gene function, genetic analysis uses large perturbations such as gene deletion, knockdown or over-expression. Large perturbations have drawbacks: they move the cell far from its normal working point, and can thus be masked by off-target effects or compensation by other genes. Here, we offer a complementary approach, called noise genetics. We use natural cell-cell variations in protein level and localization, and correlate them to the natural variations of the phenotype of the same cells. Observing these variations is made possible by recent advances in dynamic proteomics that allow measuring proteins over time in individual living cells. Using motility of human cancer cells as a model system, and time-lapse microscopy on 566 fluorescently tagged proteins, we found 74 candidate motility genes whose level or localization strongly correlate with motility in individual cells. We recovered 30 known motility genes, and validated several novel ones by mild knockdown experiments. Noise genetics can complement standard genetics for a variety of phenotypes.

  10. The Common Inhalational Anesthetic Sevoflurane Induces Apoptosis and Increases β-Amyloid Protein Levels

    Science.gov (United States)

    Dong, Yuanlin; Zhang, Guohua; Zhang, Bin; Moir, Robert D.; Xia, Weiming; Marcantonio, Edward R.; Culley, Deborah J.; Crosby, Gregory; Tanzi, Rudolph E.; Xie, Zhongcong

    2009-01-01

    Objective: To assess the effects of sevoflurane, the most commonly used inhalation anesthetic, on apoptosis and β-amyloid protein (Aβ) levels in vitro and in vivo. Subjects: Naive mice, H4 human neuroglioma cells, and H4 human neuroglioma cells stably transfected to express full-length amyloid precursor protein. Interventions: Human H4 neuroglioma cells stably transfected to express full-length amyloid precursor protein were exposed to 4.1% sevoflurane for 6 hours. Mice received 2.5% sevoflurane for 2 hours. Caspase-3 activation, apoptosis, and Aβ levels were assessed. Results: Sevoflurane induced apoptosis and elevated levels of β-site amyloid precursor protein-cleaving enzyme and Aβ in vitro and in vivo. The caspase inhibitor Z-VAD decreased the effects of sevoflurane on apoptosis and Aβ. Sevoflurane-induced caspase-3 activation was attenuated by the γ-secretase inhibitor L-685,458 and was potentiated by Aβ. These results suggest that sevoflurane induces caspase activation which, in turn, enhances β-site amyloid precursor protein–cleaving enzyme and Aβ levels. Increased Aβ levels then induce further rounds of apoptosis. Conclusions: These results suggest that inhalational anesthetic sevoflurane may promote Alzheimer disease neuropathogenesis. If confirmed in human subjects, it may be prudent to caution against the use of sevoflurane as an anesthetic, especially in those suspected of possessing excessive levels of cerebral Aβ. PMID:19433662

  11. Interactions of foot-and-mouth disease virus with soluble bovine alphaVbeta3 and alphaVbeta6 integrins.

    Science.gov (United States)

    Duque, Hernando; LaRocco, Michael; Golde, William T; Baxt, Barry

    2004-09-01

    adsorption. Virus incubated with soluble alphaVbeta6 had a lower sedimentation rate than native virus on sucrose density gradients, but the particles retained all of their structural proteins and still contained bound integrin and, therefore, were not exhibiting characteristics of a picornavirus A particle. Copyright 2004 American Society for Microbiology

  12. 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

  13. Elevated levels of the mismatch repair protein PMS2 are associated with prostate cancer.

    Science.gov (United States)

    Norris, Alixanna M; Woodruff, R D; D'Agostino, Ralph B; Clodfelter, Jill E; Scarpinato, Karin Drotschmann

    2007-02-01

    Defects in mismatch repair (MMR) proteins have been identified in various types of cancer. However, an association with prostate cancer has been controversial. Defective MMR results in genome instability with detrimental consequences that significantly contribute to tumorigenesis. This study determined alterations in key MMR protein levels in prostate cancer with the goal to identify prognostic markers. Prostatectomy samples were immunohistochemically stained and the relative presence or absence of key proteins MSH2, MLH1, and PMS2 determined. Cancer tissue of distinct grades was compared with the normal surrounding tissue. Microsatellite instability (MSI) in altered tissues was determined according to NCI guidelines. In contrast to reports that associate a lack of individual MMR proteins with tumorigenesis, a significant increase in PMS2 levels was identified in PIN lesions and prostate cancer tissue. This elevation in PMS2 was independent of changes in levels in its heterodimeric partner, MLH1. Prostate tumors with elevated levels of PMS2 were genetically unstable, which was corrected by MLH1 co-elevation. This is the first documentation of detrimental consequences associated with the increase in a MMR protein in human cancer. This study recognizes PMS2 elevation as a prognostic marker in pre-neoplastic and prostate cancer lesions. This result has significant implications for future diagnostic and treatment measures. (c) 2006 Wiley-Liss, Inc.

  14. 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

  15. 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.

  16. In vitro effect of dietary protein level and nondigestible oligosaccharides on feline fecal microbiota.

    Science.gov (United States)

    Pinna, C; Stefanelli, C; Biagi, G

    2014-12-01

    The aim of the present study was to evaluate in vitro the effect of some prebiotic substances and 2 dietary protein levels on the composition and activity of feline fecal microbiota. Two in vitro studies were conducted. First, 6 nondigestible oligosaccharides were studied; treatments were control diet (CTRL), gluconic acid (GA), carrot fiber (CF), fructooligosaccharides (FOS), galactooligosaccharides (GOS), lactitol (LAC), and pectins from citrus fruit (PEC). Substrates were added to feline fecal cultures at 2 g/L for 24 h incubation. Compared with the CTRL, ammonia had been reduced (Pmicrobiota and that high dietary protein levels in a cat's diet can have negative effects on the animal intestinal environment.

  17. 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

  18. An inducible expression system for high-level expression of recombinant proteins in slow growing mycobacteria.

    Science.gov (United States)

    Leotta, Lisa; Spratt, Joanne M; Kong, Carlyn U; Triccas, James A

    2015-09-01

    A novel protein expression vector utilising the inducible hspX promoter of Mycobacterium tuberculosis was constructed and evaluated in this study. High-level induction of three mycobacterial antigens, comprising up to 9% of bacterial sonicate, was demonstrated in recombinant Mycobacterium bovis BCG when grown under low-oxygen tension, which serves to enhance hspX promoter activity. Recombinant proteins were efficiently purified from bacterial lysates in a soluble form by virtue of a C-terminal 6-histidine tag. Purification of the immunodominant M. tuberculosis Ag85B antigen using this system resulted in a recombinant protein that stimulated significant IFN-γ release from Ag85B-reactive T cells generated after vaccination of mice with an Ag85B-expressing vaccine. Further, the M. tuberculosis L-alanine dehydrogenase (Ald) protein purified from recombinant BCG displayed strong enzymatic activity in recombinant form. This study demonstrated that high levels of native-like recombinant mycobacterial proteins can be produced in mycobacterial hosts, and this may aid the analysis of mycobacterial protein function and the development of new treatments. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. The effects of maternal total protein, albumin and hemoglobin levels on birth weight

    Directory of Open Access Journals (Sweden)

    Berna Haliloglu

    2007-12-01

    Full Text Available OBJECTIVE: The present study was designed to investigate the influence of third trimester maternal total protein, albumin, hemoglobin levels on birth weight.\tMATERIAL-METHOD: Between January 2005 and July 2005, 750 pregnant women applied for delivery at Zeynep Kamil Women’s and Children Education and Research Hospital at 37-40 week’s gestation were examined. Maternal total protein, albumin and hemoglobin levels were measured. Data included maternal age, gravidity, parity, gestational age, birth weight, gender, presence of iron supplementation and its duration.\tRESULTS: The birth weight was significantly higher in anemic and hypoproteinemic groups compared those with normal levels. After adjusting for counfounding factors, significance of both findings lost. The cases received iron supplementation had infants with higher birth weight, however, it was not statistically significant (p: 0.055. A significant positive relation was observed between birth weight and maternal age, gravidity, parity and gestational age. No relation found between maternal total protein, albumin, hemoglobin levels and birth weight.\tCONCLUSION: The last trimester maternal total protein, albumin, hemoglobin levels seem not to be a determining factor on infant's birth weight.

  20. Investigation of the molecular level interactions between mucins and food proteins: Spectroscopic, tribological and rheological studies

    DEFF Research Database (Denmark)

    Celebioglu, Hilal Yilmaz

    The thesis investigated the structure and molecular-level interaction of β-lactoglobulin (BLG) and mucins, representing major components of the dairy products and saliva/digestion systems, respectively. Mucins are long glycoprotein molecules responsible for the gel nature of the mucous layer covers...... epithelial surfaces throughout the body. A literature review of the interactions of different mucin types and saliva mucins with several food proteins and food protein emulsions, as well as their functional properties related to the food oral processing is presented at the first chapter of the thesis (Paper...... V). Most of the studies suggest an electrostatic attraction between positively charged food proteins with negatively charged moieties of mucins (mainly on glycosylated region of mucins). The structural changes occurring during the interaction between BLG, the major whey protein, and bovine...

  1. Effect of voluntary exercise and dietary protein levels on incorporation of 14C-leucine into protein by mice liver slices in vitro

    International Nuclear Information System (INIS)

    Yashiro, Masanori; Kimura, Shuichi

    1983-01-01

    The effect of voluntary exercise on incorporation of 14 C-leucine into protein by mice liver slices in vitro were examined with mice fed 4 %, 6 % and 20 % protein diets. The incorporation of 14 C-leucine increased as dietary protein levels decreased and was significantly higher in liver slices of exercise groups than in slices of non-exercise groups. (author)

  2. Integrin-based meningioma cell migration is promoted by photon but not by carbon-ion irradiation

    International Nuclear Information System (INIS)

    Simon, Florian; Dittmar, Jan-Oliver; Orschiedt, Lena; Weber, Klaus-Josef; Debus, Juergen; Rieken, Stefan; Brons, Stephan; Urbschat, Steffi; Combs, Stephanie E.

    2015-01-01

    Sublethal doses of photon irradiation (IR) are suspected to increase tumor cell migration and support locoregional recurrence of disease, which has already been shown in other cell lines. This manuscript describes the effect of photon and carbon-ion IR on WHO class I meningioma cell migration and provides an approach to the underlying cellular mechanisms. Meningioma cells were gained operatively at the university hospital in Homburg/Saar, Germany. For migration, membranes (8-μm pore sizes) were coated with collagen I, with collagen IV, and with fibronectin. Cells were analyzed in migration experiments with or without serum stimulation, with or without photon and carbon IR 24 h prior to experiments, and with or without integrin antibodies. Fluorescence-activated cell sorting (FACS) analyses of the integrins ανβ 1 , ανβ 3 , and ανβ 5 were performed without IR and 6, 12 and 24 h after IR. Enzyme-linked immunosorbent assay (ELISA) analyses of matrix metalloproteinases (MMP)-2 and MMP-9 were realized with and without IR after cells were cultured on collagen I, collagen IV, or fibronectin for 24 h. Cells and supernatants for FACS and ELISA were stored at - 18 C. The significance level was set at 5 % using both Student's t test and two-way ANOVA. Migration of meningioma cells was serum-inducible (p < 0.001). It could be increased by photon IR (p < 0.02). The integrins ανβ 1 and ανβ 5 showed a 21 and 11 % higher expression after serum stimulation (not significant), respectively, and ανβ 1 expression was raised by 14 % (p = 0.0057) after photon IR. Antibody blockage of the integrins ανβ 1 and ανβ 5 inhibited serum- and photon-induced migration. Expression of MMP-2 and MMP-9 remained unchanged after both IR and fetal bovine serum (FBS). Carbon-ion IR left both integrin expression and meningioma cell migration unaffected. Photon but not carbon-ion IR promotes serum-based meningioma cell migration. Fibronectin receptor integrin ανβ 1 signaling

  3. Effects of dietary protein level on nutrients digestibility and reproductive performance of female mink (Neovison vison during gestation

    Directory of Open Access Journals (Sweden)

    Qingkui Jiang

    2015-06-01

    Full Text Available The objective of this study was to determine whether nutrient digestibility and reproductive performance of pregnant mink (Neovison vison were affected by different dietary protein levels. One hundred and twenty female mink were randomly assigned to four groups, receiving diets of fresh material with different protein levels. The dietary protein levels, expressed as percentage of dry matter (DM, were 32, 36, 40 and 44% respectively. These values corresponded to average 320, 360, 400 and 440 g protein/kg DM, respectively. Results were as follows. All of crude protein digestibility, nitrogen (N intake, N retention increased along with dietary protein level increasing. Low protein level (32% significantly reduced the above indicators (P < 0.05. DM digestibility and ether extract digestibility were not affected by dietary protein level. Results of mated females, barren females, kids per litter, live born kids per mated female, birth survival rate, and birth weight showed that mink achieved optimal reproductive performance when dietary protein level was 36%. In conclusion, dietary protein was anticipated to significantly influence some nutrients' utilization. Adopting the appropriate dietary protein level allow better reproduction performance. The most preferable reproductive performance was achieved when diet contained 275.5 g digestible protein per kg DM for female mink in gestation.

  4. Regulation of the Contribution of Integrin to Cell Attachment on Poly(2-Methoxyethyl Acrylate (PMEA Analogous Polymers for Attachment-Based Cell Enrichment.

    Directory of Open Access Journals (Sweden)

    Takashi Hoshiba

    Full Text Available Cell enrichment is currently in high demand in medical engineering. We have reported that non-blood cells can attach to a blood-compatible poly(2-methoxyethyl acrylate (PMEA substrate through integrin-dependent and integrin-independent mechanisms because the PMEA substrate suppresses protein adsorption. Therefore, we assumed that PMEA analogous polymers can change the contribution of integrin to cell attachment through the regulation of protein adsorption. In the present study, we investigated protein adsorption, cell attachment profiles, and attachment mechanisms on PMEA analogous polymer substrates. Additionally, we demonstrated the possibility of attachment-based cell enrichment on PMEA analogous polymer substrates. HT-1080 and MDA-MB-231 cells started to attach to poly(butyl acrylate (PBA and poly(tetrahydrofurfuryl acrylate (PTHFA, on which proteins could adsorb well, within 1 h. HepG2 cells started to attach after 1 h. HT-1080, MDA-MB-231, and HepG2 cells started to attach within 30 min to PMEA, poly(2-(2-methoxyethoxy ethyl acrylate-co-butyl acrylate (30:70 mol%, PMe2A and poly(2-(2-methoxyethoxy ethoxy ethyl acrylate-co-butyl acrylate (30:70 mol%, PMe3A, which suppress protein adsorption. Moreover, the ratio of attached cells from a cell mixture can be changed on PMEA analogous polymers. These findings suggested that PMEA analogous polymers can be used for attachment-based cell enrichment.

  5. The interaction of HAb18G/CD147 with integrin α6β1 and its implications for the invasion potential of human hepatoma cells

    Directory of Open Access Journals (Sweden)

    Tang Juan

    2009-09-01

    Full Text Available Abstract Background HAb18G/CD147 plays pivotal roles in invasion by hepatoma cells, but the underlying mechanism remains unclear. Our previous study demonstrated that overexpression of HAb18G/CD147 promotes invasion by interacting with integrin α3β1. However, it has never been investigated whether α3β1 is solely responsible for this process or if other integrin family members also interact with HAb18G/CD147 in human hepatoma cells. Methods Human SMMC-7721 and FHCC98 cells were cultured and transfected with siRNA fragments against HAb18G/CD147. The expression levels of HAb18G/CD147 and integrin α6β1 were determined by immunofluorescent double-staining and confocal imaging analysis. Co-immunoprecipitation and Western blot analyses were performed to examine the native conformations of HAb18G/CD147 and integrin α6β1. Invasion potential was evaluated with an invasion assay and gelatin zymography. Results We found that integrin α6β1 co-localizes and interacts with HAb18G/CD147 in human hepatoma cells. The enhancing effects of HAb18G/CD147 on invasion capacity and secretion of matrix metalloproteinases (MMPs were partially blocked by integrin α6β1 antibodies (P 2+ mobilization, significantly reduced cell invasion potential and secretion of MMPs in human hepatoma cells (P Conclusion These results suggest that α6β1 interacts with HAb18G/CD147 to mediate tumor invasion and metastatic processes through the PI3K pathway.

  6. Effects of nutritional supplementation on periodontal parameters, carotenoid antioxidant levels, and serum C-reactive protein.

    Science.gov (United States)

    Harpenau, Lisa A; Cheema, Abida T; Zingale, Joseph A; Chambers, David W; Lundergan, William P

    2011-05-01

    Few studies have focused on the role of nutrition in periodontal disease. The purpose of this trial was to determine the effect of a nutritional supplement on gingival inflammation, bleeding, probing depth, clinical attachment level, carotenoid antioxidant level, and C-reactive protein. The test supplement, consisting of a standard multivitamin formula, as well as several phytonutrients associated with antiinflammatory/antioxidant effects, provided modest benefits in reducing inflammation; however, further studies with larger populations and longer intervention are warranted.

  7. Effects of energy and protein levels on growth and nutrient utilization ...

    African Journals Online (AJOL)

    Effects of energy and protein levels on growth and nutrient utilization of weaned rabbits. ML Egbo, TA Adegbola, EO Oyawoye, MM Abubakar. Abstract. No Abstract. Animal Production Research Advances Vol. 3 (4) 2007: pp. 306-310. http://dx.doi.org/10.4314/apra.v3i4.36411 · AJOL African Journals Online. HOW TO USE ...

  8. Levels of ABA, its precursors and dehydrin-like proteins during ...

    African Journals Online (AJOL)

    2Department of Molecular Biology and Biotechnology, University of Dar es Salaam,. P.O Box 35179, Dar ... to combat stress. Levels of ABA and proteins that cross reacted with an anti – dehydrin ...... Cambridge, Melbourne). Wang, X.-Q., Ullah ...

  9. Systemic Glucose Level Changes with a Carbohydrate-Restricted and Higher Protein Diet Combined with Exercise

    Science.gov (United States)

    Bowden, Rodney G.; Lanning, Beth A.; Doyle, Eva I.; Slonaker, Becky; Johnston, Holly M.; Scanes, Georgene

    2007-01-01

    Objective: The authors' purpose in this study was to compare the effects of macronutrient intake on systemic glucose levels in previously sedentary participants who followed 1 of 4 diets that were either higher protein or high carbohydrate, while initiating an exercise program. Participants and Methods: The authors randomly assigned 94 sedentary…

  10. Altered protein and iron levels of patients with active tuberculosis in ...

    African Journals Online (AJOL)

    Backgound: Tuberculosis as a state of chronic inflammation impacts on haematologic functions of the body. Objectives: This study aimed at assessing iron parameters and serum protein levels of ninety tuberculosis patients aged fifteen to sixty years, enrolled from Dr Lawrence Henshaw Memorial Hospital, Calabar, Nigeria.

  11. CSF Neurofilament Proteins Levels are Elevated in Sporadic Creutzfeldt-Jakob Disease

    NARCIS (Netherlands)

    van Eijk, Jeroen J. J.; van Everbroeck, Bart; Abdo, W. Farid; Kremer, Berry P. H.; Verbeek, Marcel M.

    2010-01-01

    In this study we investigated the cerebrospinal fluid (CSF) levels of neurofilament light (NFL) and heavy chain (NFHp35), total tau (t-tau), and glial fibrillary acidic protein (GFAP) to detect disease specific profiles in sporadic Creutzfeldt Jakob disease (sCJD) patients and Alzheimer's disease

  12. Modeling of DNA and Protein Organization Levels with Cn3D Software

    Science.gov (United States)

    Stasinakis, Panagiotis K.; Nicolaou, Despoina

    2017-01-01

    The molecular structure of living organisms and the complex interactions amongst its components are the basis for the diversity observed at the macroscopic level. Proteins and nucleic acids are some of the major molecular components, and play a key role in several biological functions, such as those of development and evolution. This article…

  13. Plasma levels of C-Reactive Protein and Fibrinogen in Pulmonary ...

    African Journals Online (AJOL)

    In this study, we determined the changes in plasma C- reactive protein (C-RP) and Fibrinogen levels in Drug sensitive Tuberculosis (DSTB) patients at diagnosis, Multi drug resistant tuberculosis (MDRTB) patients at diagnosis and during chemotherapy. Twenty-four (24) patients MDRTB patients and 24 newly diagnosed ...

  14. Protein C and antithrombin levels in patients with sickle cell anemia ...

    African Journals Online (AJOL)

    Background: Alterations in the components of hemostasis, namely platelet function, the procoagulant, anticoagulant, and the fibrinolytic systems, are observed in sickle cell anemia (SCA) and are in favor of a procoagulant phenotype. Therefore, study of protein C and antithrombin (AT) levels in patients with SCA in steady ...

  15. Up-regulation of integrin β3 in radioresistant pancreatic cancer impairs adenovirus-mediated gene therapy

    International Nuclear Information System (INIS)

    Egami, Takuya; Ohuchida, Kenoki; Yasui, Takaharu; Onimaru, Manabu; Toma, Hiroki; Sato, Norihiro; Tanaka, Masao; Mizumoto, Kazuhiro; Matsumoto, Kunio

    2009-01-01

    Adenovirus-mediated gene therapy is a promising approach for the treatment of pancreatic cancer. We previously reported that radiation enhanced adenovirus-mediated gene expression in pancreatic cancer, suggesting that adenoviral gene therapy might be more effective in radioresistant pancreatic cancer cells. In the present study, we compared the transduction efficiency of adenovirus-delivered genes in radiosensitive and radioresistant cells, and investigated the underlying mechanisms. We used an adenovirus expressing the hepatocyte growth factor antagonist, NK4 (Ad-NK4), as a representative gene therapy. We established two radioresistant human pancreatic cancer cell lines using fractionated irradiation. Radiosensitive and radioresistant pancreatic cancer cells were infected with Ad-NK4, and NK4 levels in the cells were measured. In order to investigate the mechanisms responsible for the differences in the transduction efficiency between these cells, we measured expression of the genes mediating adenovirus infection and endocytosis. The results revealed that NK4 levels in radioresistant cells were significantly lower (P<0.01) than those in radiosensitive cells, although there were no significant differences in adenovirus uptake between radiosensitive cells and radioresistant cells. Integrin β3 was up-regulated and the Coxsackie virus and adenovirus receptor was down-regulated in radioresistant cells, and inhibition of integrin β3 promoted adenovirus gene transfer. These results suggest that inhibition of integrin β3 in radioresistant pancreatic cancer cells could enhance adenovirus-mediated gene therapy. (author)

  16. Inhibiting Vimentin or beta 1-integrin Reverts Prostate Tumor Cells in IrECM and Reduces Tumor Growth

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xueping; Fournier, Marcia V.; Ware, Joy L.; Bissell, Mina J.; Zehner, Zendra E.

    2009-07-27

    Prostate epithelial cells grown embedded in laminin-rich extracellular matrix (lrECM) undergo morphological changes that closely resemble their architecture in vivo. In this study, growth characteristics of three human prostate epithelial sublines derived from the same cellular lineage, but displaying different tumorigenic and metastatic properties in vivo, were assessed in three-dimensional (3D) lrECM gels. M12, a highly tumorigenic and metastatic subline, was derived from the parental prostate epithelial P69 cell line by selection in nude mice and found to contain a deletion of 19p-q13.1. The stable reintroduction of an intact human chromosome 19 into M12 resulted in a poorly tumorigenic subline, designated F6. When embedded in lrECM gels, the nontumorigenic P69 line produced acini with clearly defined lumena. Immunostaining with antibodies to {beta}-catenin, E-cadherin or {alpha}6-, {beta}4- and {beta}1-integrins showed polarization typical of glandular epithelium. In contrast, the metastatic M12 subline produced highly disorganized cells with no evidence of polarization. The F6 subline reverted to acini-like structures exhibiting basal polarity marked with integrins. Reducing either vimentin levels via siRNA interference or {beta}1-integrin expression by the addition of the blocking antibody, AIIB2, reorganized the M12 subline into forming polarized acini. The loss of vimentin significantly reduced M12-Vim tumor growth when assessed by subcutaneous injection in athymic mice. Thus, tumorigenicity in vivo correlated with disorganized growth in 3D lrECM gels. These studies suggest that the levels of vimentin and {beta}1-integrin play a key role in the homeostasis of the normal acini in prostate and that their dysregulation may lead to tumorigenesis.

  17. 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.

  18. 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.

  19. 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.

  20. Pharmacokinetics of 99m Tc-EDDA/HYNIC-Lys-D-Phe-RGD in athymic mice with induced malignant tumors for integrin imaging

    International Nuclear Information System (INIS)

    Lopez D, F.A.; Pedraza L, M.; Murphy, C.A. de; Ferro F, G.; Hernandez H, E.

    2007-01-01

    Full text: Nuclear medicine imaging techniques are non-invasive and monitor the spatiotemporal distribution of molecular events. Radiolabeled RGD-peptides are currently investigated to target integrin receptors for in vivo tumor imaging. The α v β 3 integrin is a target structure involved in the angio genesis process which mediates the binding to extracellular matrix via different proteins such as vitronectin, fibronectin and von Willebrand factor. The aim of this research was to prepare [ 99m Tc]-Lys-D-Phe-RGD and to evaluate its pharmacokinetics in athymic mice with three different induced malignant tumors. Tumor uptake values of 99m Tc-Lys-D-Phe-RGD labeled via HYNIC and EDDA showed good ability to target α v β 3 integrin receptors in the three different kinds of tumors (breast, prostate and neuroendocrine). A high in vivo stability and favorable pharmacokinetic properties such as fast blood clearance, rapid renal excretion, low liver and muscle uptake and low intestinal excretion were observed. This study demonstrated that 99m Tc-EDDA/HYNIC-Lys-D-Phe-RGD is a specific and potential radiopharmaceutical to image α v β 3 integrin receptors in a variety of tumors. (Author)

  1. Flour sodium dodecyl sulfate (SDS)-extractable protein level as a cookie flour quality indicator.

    Science.gov (United States)

    Pareyt, Bram; Bruneel, Charlotte; Brijs, Kristof; Goesaert, Hans; Delcour, Jan A

    2010-01-13

    Flour characteristics of laboratory-milled flour fractions of two wheat cultivars were related to their cookie-baking performance. Cultivar (cv.) Albatros wheat milling yielded fractions with lower damaged starch (DS) and arabinoxylan levels and higher sodium dodecyl sulfate-extractable protein (SDSEP) levels than did cv. Meunier wheat milling. During baking, cv. Albatros flour doughs spread faster and set later than their cv. Meunier counterparts and, hence, resulted in larger cookie diameters. DS levels negatively affected spread rate during both cv. Albatros (R2=0.68) and cv. Meunier (R2=0.51) cookie baking. SDSEP levels also influenced cookie quality. The use of flour heat-treated to reduce its SDSEP levels to different degrees led to reduction of the set time (R2=0.90). It was deduced that larger gluten polymer sizes limit dough spread time during baking and that, apart from DS level, the SDSEP level is an indicator for cookie flour quality.

  2. Comparison of C-reactive protein and high-sensitivity C-reactive protein levels in patients on hemodialysis

    Directory of Open Access Journals (Sweden)

    Imed Helal

    2012-01-01

    Full Text Available Chronic inflammation is highly prevalent in patients on hemodialysis (HD, as evidenced by increased levels of C-reactive protein (CRP. We compared CRP to high-sensitivity C-reactive protein (hs-CRP to determine whether it has any clinical implications and prognostic significance in terms of mortality. CRP was measured using a standard immunoturbidometric assay on the COBAS; INTEGRA system and hs-CRP was measured using the Dade Behring on the Konelab Nephelometer in 50 patients on HD. CRP (≥6 mg/L and hs-CRP (≥3 mg/L levels were elevated in 30% and 54% of the patients, respectively. A significant correlation was noted between hs-CRP and CRP levels (r = 0.98, P <0.001. Deming regression analysis showed that the slope was near one (r = 0.90; 0.83-0.94 and that the intercept was small. Multivariate regression confirmed that age above 40 years (RR = 3.69, P = 0.027 and duration on HD greater than five years (RR = 3.71, P = 0.028 remained significant independent predictors of serum hs-CRP. Thirteen patients died during follow-up (26%. Multivariate Cox regression demonstrated that hs-CRP (RR = 1.062, P = 0.03 and CRP levels (RR = 1.057, P = 0.009 and age (RR = 1.078, P = 0.001 were the most powerful predictors of mortality. The CRP standard assay presents a reasonable alternative to the hs-CRP assay in patients on HD. The advantages of the CRP standard assay are its online and real-time availability as well as lower costs, particularly in developing countries.

  3. 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...

  4. Endostatin gene variation and protein levels in breast cancer susceptibility and severity

    International Nuclear Information System (INIS)

    Balasubramanian, Sabapathy P; Cross, Simon S; Globe, Jenny; Cox, Angela; Brown, Nicola J; Reed, Malcolm W

    2007-01-01

    Endostatin is a potent endogenous anti-angiogenic agent which inhibits tumour growth. A non-synonymous coding polymorphism in the Endostatin gene is thought to affect Endostatin activity. We aimed to determine the role of this Endostatin polymorphism in breast cancer pathogenesis and any influence on serum Endostatin levels in healthy volunteers. Endostatin protein expression on a breast cancer micro array was also studied to determine any relationship to genotype and to breast cancer prognosis. The 4349G > A (coding non-synonymous) polymorphism in exon 42 of the Endostatin gene was genotyped in approximately 846 breast cancer cases and 707 appropriate controls. In a separate healthy cohort of 57 individuals, in addition to genotyping, serum Endostatin levels were measured using enzyme linked immunosorbant assay (ELISA). A semi-quantitative assessment of Endostatin protein expression on immunostained tissue micro arrays (TMA) constructed from breast cancer samples of patients with genotype data was performed. The rare allele (A) was significantly associated with invasive breast cancers compared to non-invasive tumours (p = 0.03), but there was no association with tumour grade, nodal status, vascular invasion or overall survival. There was no association with breast cancer susceptibility. Serum Endostatin levels and Endostatin protein expression on the tissue micro array were not associated with genotype. The Endostatin 4349A allele is associated with invasive breast cancer. The Endostatin 4349G > A polymorphism however does not appear to be associated with breast cancer susceptibility or severity in invasive disease. By studying circulating levels and tumour Endostatin protein expression, we have shown that any influence of this polymorphism is unlikely to be through an effect on the levels of protein produced

  5. Antisense oligonucleotides targeting translation inhibitory elements in 5' UTRs can selectively increase protein levels.

    Science.gov (United States)

    Liang, Xue-Hai; Sun, Hong; Shen, Wen; Wang, Shiyu; Yao, Joyee; Migawa, Michael T; Bui, Huynh-Hoa; Damle, Sagar S; Riney, Stan; Graham, Mark J; Crooke, Rosanne M; Crooke, Stanley T

    2017-09-19

    A variety of diseases are caused by deficiencies in amounts or activity of key proteins. An approach that increases the amount of a specific protein might be of therapeutic benefit. We reasoned that translation could be specifically enhanced using trans-acting agents that counter the function of negative regulatory elements present in the 5' UTRs of some mRNAs. We recently showed that translation can be enhanced by antisense oligonucleotides (ASOs) that target upstream open reading frames. Here we report the amount of a protein can also be selectively increased using ASOs designed to hybridize to other translation inhibitory elements in 5' UTRs. Levels of human RNASEH1, LDLR, and ACP1 and of mouse ACP1 and ARF1 were increased up to 2.7-fold in different cell types and species upon treatment with chemically modified ASOs targeting 5' UTR inhibitory regions in the mRNAs encoding these proteins. The activities of ASOs in enhancing translation were sequence and position dependent and required helicase activity. The ASOs appear to improve the recruitment of translation initiation factors to the target mRNA. Importantly, ASOs targeting ACP1 mRNA significantly increased the level of ACP1 protein in mice, suggesting that this approach has therapeutic and research potentials. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

  6. Levels of digestible protein to surubim (Pseudoplatystoma sp. reared in net cages

    Directory of Open Access Journals (Sweden)

    Claucia Aparecida Honorato

    2014-10-01

    Full Text Available The Pseudoplatystoma sp. is species of carnivorous fish that require special attention in the diet offered. This work had the objective to determine the digestible protein requirement of juvenile the Pseudoplatystoma sp. reared in net cages. The test consisted of four isoenergetic diets (2606.69 ± 39.16 kcal kg-1 of digestible energy containing increasing levels of digestible protein (23, 24, 26 and 28%PD provided to juveniles of surubim (157.35±11.23g for five months. The parameters of growth, fillet composition, metabolic liver enzymes and morphometry of the intestine and liver were analyzed in completely randomized design with four treatments and four replicates. An increase of protein in the diet provided better weight gain. The metabolic liver enzymes increased in fish fed 24PD. The histopathological changes were not observed in the liver of the fish. The bowel histology showed adaptation to increased protein in the diet until the 26 level PD. juveniles of Pseudoplatystoma sp. Were demanding in digestible protein, showing the best results of production performance and nutrient use efficiency with the diet containing 28%PD.

  7. Multiple proteins of White spot syndrome virus involved in ...

    Indian Academy of Sciences (India)

    2014-03-20

    Mar 20, 2014 ... β-integrin with structure proteins of WSSV and motifs involved in WSSV infection was examined. The results showed ... Introduction. White spot ... denatured conditions and renatured by successive 12 h incu- bations with 6, 4, ...

  8. Trace levels of innate immune response modulating impurities (IIRMIs) synergize to break tolerance to therapeutic proteins.

    Science.gov (United States)

    Verthelyi, Daniela; Wang, Vivian

    2010-12-22

    Therapeutic proteins such as monoclonal antibodies, replacement enzymes and toxins have significantly improved the therapeutic options for multiple diseases, including cancer and inflammatory diseases as well as enzyme deficiencies and inborn errors of metabolism. However, immune responses to these products are frequent and can seriously impact their safety and efficacy. Of the many factors that can impact protein immunogenicity, this study focuses on the role of innate immune response modulating impurities (IIRMIs) that could be present despite product purification and whether these impurities can synergize to facilitate an immunogenic response to therapeutic proteins. Using lipopolysaccharide (LPS) and CpG ODN as IIRMIs we showed that trace levels of these impurities synergized to induce IgM, IFNγ, TNFα and IL-6 expression. In vivo, trace levels of these impurities synergized to increase antigen-specific IgG antibodies to ovalbumin. Further, whereas mice treated with human erythropoietin showed a transient increase in hematocrit, those that received human erythropoietin containing low levels of IIRMIs had reduced response to erythropoietin after the 1(st) dose and developed long-lasting anemia following subsequent doses. This suggests that the presence of IIRMIs facilitated a breach in tolerance to the endogenous mouse erythropoietin. Overall, these studies indicate that the risk of enhancing immunogenicity should be considered when establishing acceptance limits of IIRMIs for therapeutic proteins.

  9. Protein logic: a statistical mechanical study of signal integration at the single-molecule level.

    Science.gov (United States)

    de Ronde, Wiet; Rein ten Wolde, Pieter; Mugler, Andrew

    2012-09-05

    Information processing and decision-making is based upon logic operations, which in cellular networks has been well characterized at the level of transcription. In recent years, however, both experimentalists and theorists have begun to appreciate that cellular decision-making can also be performed at the level of a single protein, giving rise to the notion of protein logic. Here we systematically explore protein logic using a well-known statistical mechanical model. As an example system, we focus on receptors that bind either one or two ligands, and their associated dimers. Notably, we find that a single heterodimer can realize any of the 16 possible logic gates, including the XOR gate, by variation of biochemical parameters. We then introduce what to our knowledge is a novel idea: that a set of receptors with fixed parameters can encode functionally unique logic gates simply by forming different dimeric combinations. An exhaustive search reveals that the simplest set of receptors (two single-ligand receptors and one double-ligand receptor) can realize several different groups of three unique gates, a result for which the parametric analysis of single receptors and dimers provides a clear interpretation. Both results underscore the surprising functional freedom readily available to cells at the single-protein level. Copyright © 2012 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  10. Trace levels of innate immune response modulating impurities (IIRMIs synergize to break tolerance to therapeutic proteins.

    Directory of Open Access Journals (Sweden)

    Daniela Verthelyi

    Full Text Available Therapeutic proteins such as monoclonal antibodies, replacement enzymes and toxins have significantly improved the therapeutic options for multiple diseases, including cancer and inflammatory diseases as well as enzyme deficiencies and inborn errors of metabolism. However, immune responses to these products are frequent and can seriously impact their safety and efficacy. Of the many factors that can impact protein immunogenicity, this study focuses on the role of innate immune response modulating impurities (IIRMIs that could be present despite product purification and whether these impurities can synergize to facilitate an immunogenic response to therapeutic proteins. Using lipopolysaccharide (LPS and CpG ODN as IIRMIs we showed that trace levels of these impurities synergized to induce IgM, IFNγ, TNFα and IL-6 expression. In vivo, trace levels of these impurities synergized to increase antigen-specific IgG antibodies to ovalbumin. Further, whereas mice treated with human erythropoietin showed a transient increase in hematocrit, those that received human erythropoietin containing low levels of IIRMIs had reduced response to erythropoietin after the 1(st dose and developed long-lasting anemia following subsequent doses. This suggests that the presence of IIRMIs facilitated a breach in tolerance to the endogenous mouse erythropoietin. Overall, these studies indicate that the risk of enhancing immunogenicity should be considered when establishing acceptance limits of IIRMIs for therapeutic proteins.

  11. Stable Plastid Transformation for High-Level Recombinant Protein Expression: Promises and Challenges

    Directory of Open Access Journals (Sweden)

    Meili Gao

    2012-01-01

    Full Text Available Plants are a promising expression system for the production of recombinant proteins. However, low protein productivity remains a major obstacle that limits extensive commercialization of whole plant and plant cell bioproduction platform. Plastid genetic engineering offers several advantages, including high levels of transgenic expression, transgenic containment via maternal inheritance, and multigene expression in a single transformation event. In recent years, the development of optimized expression strategies has given a huge boost to the exploitation of plastids in molecular farming. The driving forces behind the high expression level of plastid bioreactors include codon optimization, promoters and UTRs, genotypic modifications, endogenous enhancer and regulatory elements, posttranslational modification, and proteolysis. Exciting progress of the high expression level has been made with the plastid-based production of two particularly important classes of pharmaceuticals: vaccine antigens, therapeutic proteins, and antibiotics and enzymes. Approaches to overcome and solve the associated challenges of this culture system that include low transformation frequencies, the formation of inclusion bodies, and purification of recombinant proteins will also be discussed.

  12. The dermatan sulfate proteoglycan decorin modulates α2β1 integrin and the vimentin intermediate filament system during collagen synthesis.

    Directory of Open Access Journals (Sweden)

    Oliver Jungmann

    Full Text Available Decorin, a small leucine-rich proteoglycan harboring a dermatan sulfate chain at its N-terminus, is involved in regulating matrix organization and cell signaling. Loss of the dermatan sulfate of decorin leads to an Ehlers-Danlos syndrome characterized by delayed wound healing. Decorin-null (Dcn(-/- mice display a phenotype similar to that of EDS patients. The fibrillar collagen phenotype of Dcn(-/- mice could be rescued in vitro by decorin but not with decorin lacking the glycosaminoglycan chain. We utilized a 3D cell culture model to investigate the impact of the altered extracellular matrix on Dcn(-/- fibroblasts. Using 2D gel electrophoresis followed by mass spectrometry, we identified vimentin as one of the proteins that was differentially upregulated by the presence of decorin. We discovered that a decorin-deficient matrix leads to abnormal nuclear morphology in the Dcn(-/- fibroblasts. This phenotype could be rescued by the decorin proteoglycan but less efficiently by the decorin protein core. Decorin treatment led to a significant reduction of the α2β1 integrin at day 6 in Dcn(-/- fibroblasts, whereas the protein core had no effect on β1. Interestingly, only the decorin core induced mRNA synthesis, phosphorylation and de novo synthesis of vimentin indicating that the proteoglycan decorin in the extracellular matrix stabilizes the vimentin intermediate filament system. We could support these results in vivo, because the dermis of wild-type mice have more vimentin and less β1 integrin compared to Dcn(-/-. Furthermore, the α2β1 null fibroblasts also showed a reduced amount of vimentin compared to wild-type. These data show for the first time that decorin has an impact on the biology of α2β1 integrin and the vimentin intermediate filament system. Moreover, our findings provide a mechanistic explanation for the reported defects in wound healing associated with the Dcn(-/- phenotype.

  13. 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.

  14. Endothelial-Rac1 is not required for tumor angiogenesis unless alphavbeta3-integrin is absent.

    Directory of Open Access Journals (Sweden)

    Gabriela D'Amico

    2010-03-01

    Full Text Available Endothelial cell migration is an essential aspect of tumor angiogenesis. Rac1 activity is needed for cell migration in vitro implying a requirement for this molecule in angiogenesis in vivo. However, a precise role for Rac1 in tumor angiogenesis has never been addressed. Here we show that depletion of endothelial Rac1 expression in adult mice, unexpectedly, has no effect on tumor growth or tumor angiogenesis. In addition, repression of Rac1 expression does not inhibit VEGF-mediated angiogenesis in vivo or ex vivo, nor does it affect chemotactic migratory responses to VEGF in 3-dimensions. In contrast, the requirement for Rac1 in tumor growth and angiogenesis becomes important when endothelial beta3-integrin levels are reduced or absent: the enhanced tumor growth, tumor angiogenesis and VEGF-mediated responses in beta3-null mice are all Rac1-dependent. These data indicate that in the presence of alphavbeta3-integrin Rac1 is not required for tumor angiogenesis.

  15. Anti-carbamylated Protein Antibody Levels Correlate with Anti-Sa (Citrullinated Vimentin) Antibody Levels in Rheumatoid Arthritis.

    Science.gov (United States)

    Challener, Gregory J; Jones, Jonathan D; Pelzek, Adam J; Hamilton, B JoNell; Boire, Gilles; de Brum-Fernandes, Artur José; Masetto, Ariel; Carrier, Nathalie; Ménard, Henri A; Silverman, Gregg J; Rigby, William F C

    2016-02-01

    The presence of anticitrullinated protein antibodies (ACPA) in rheumatoid arthritis (RA) indicates a breach in immune tolerance. Recent studies indicate that this breach extends to homocitrullination of lysines with the formation of anti-carbamylated protein (anti-CarP) antibodies. We analyzed the clinical and serologic relationships of anti-CarP in 2 RA cohorts. Circulating levels of immunoglobulin G anti-CarP antibodies were determined by ELISA in established (Dartmouth-Hitchcock Medical Center) and early (Sherbrooke University Hospital Center) cohorts and evaluated for anticyclic citrullinated peptide antibodies (anti-CCP), specific ACPA, and rheumatoid factor (RF) levels using the Student t test and correlation analysis. We identified elevated anti-CarP antibodies titers in 47.0% of seropositive patients (Dartmouth, n = 164), with relationships to anti-CCP (p < 0.0001) and IgM-RF (p = 0.001). Similarly, 38.2% of seropositive patients from the Sherbrooke cohort (n = 171) had elevated anti-CarP antibodies; titers correlated to anti-CCP (p = 0.01) but not IgM-RF (p = 0.09). A strong correlation with anti-Sa was observed: 47.9% anti-Sa+ patients were anti-CarP antibodies+ versus only 25.4% anti-Sa- in the Sherbrooke cohort (p = 0.0002), and 62.6% anti-Sa+ patients versus 26.9% anti-Sa- were anti-CarP antibodies+ in Dartmouth (p < 0.0001). We found a more variable response for reactivity to citrullinated fibrinogen or to citrullinated peptides from fibrinogen and α enolase. In 2 North American RA cohorts, we observed a high prevalence of anti-CarP antibody positivity. We also describe a surprising and unexpected association of anti-CarP with anti-Sa antibodies that could not be explained by cross-reactivity. Further, considerable heterogeneity exists between anti-CarP reactivity and other citrullinated peptide reactivity, raising the question of how the pathogenesis of antibody responses for carbamylated proteins and citrullinated proteins may be linked in vivo.

  16. Role of Integrin-Beta1 in Polycystic Kidney Disease

    Science.gov (United States)

    2012-04-01

    interactions affect proliferation and cell differentiation2. We previously showed an increase of integrin-!2ŕ expression in polycystin-1 (PC1) deficient...that since the Cre activity in TgAqp2-Cre transgenic mouse was observed also in testes, our breeding scheme was devised to ensure maternal ...inheritance of the transgene, as paternal transmission would lead to gene recombination not only in the kidneys, but also in sperm and the resulting

  17. 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.

  18. 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.

  19. Evaluation of C-Reactive Protein Level in Patients with Pain Form of Temporomandibular Joint Dysfunction

    Directory of Open Access Journals (Sweden)

    Malgorzata Pihut

    2018-01-01

    Full Text Available Temporomandibular joint dysfunction is a functional disorder concerned with the abnormal functioning of the muscles of the stomatognathic system and temporomandibular joints involved in the dynamic movements of the jaw and surrounding structures. The aim of the study was to compare the level of C-reactive protein in patients with pain and painless forms of temporomandibular joint dysfunction. Materials and methods. The study group consisted of 72 patients who reported to the prosthetic treatment because of temporomandibular joint dysfunction. The study group included 36 patients with pain form of dysfunction, and the control group included 36 patients with painless form of disorder. Each patient underwent specialized examination of functional disorders in order to diagnose the type of dysfunction and was commissioned to carry out a study of the blood test concerned with evaluation of the C-reactive protein (CRP level in the same analytical laboratory. The results of the investigation were subjected to statistical analysis. The research obtained approval from the Ethics Committee of the Jagiellonian University (KBET/125/L/2013. Level of Evidence for primary research was established as type V. Results. The mean values of C-reactive protein levels in both groups were in the normal range and did not differ statistically significantly, which indicates the fact that the pain form of the temporomandibular joint disorders is not associated with inflammation of the soft tissues of the joint. Conclusion. Painful form of the temporomandibular joint dysfunctions is not connected with the inflammation of joints.

  20. Metformin induces oxidative stress in white adipocytes and raises uncoupling protein 2 levels.

    Science.gov (United States)

    Anedda, Andrea; Rial, Eduardo; González-Barroso, M Mar

    2008-10-01

    Metformin is a drug widely used to treat type 2 diabetes. It enhances insulin sensitivity by improving glucose utilization in tissues like liver or muscle. Metformin inhibits respiration, and the decrease in cellular energy activates the AMP-activated protein kinase that in turn switches on catabolic pathways. Moreover, metformin increases lipolysis and beta-oxidation in white adipose tissue, thereby reducing the triglyceride stores. The uncoupling proteins (UCPs) are transporters that lower the efficiency of mitochondrial oxidative phosphorylation. UCP2 is thought to protect against oxidative stress although, alternatively, it could play an energy dissipation role. The aim of this work was to analyse the involvement of UCP2 on the effects of metformin in white adipocytes. We studied the effect of this drug in differentiating 3T3-L1 adipocytes and found that metformin causes oxidative stress since it increases the levels of reactive oxygen species (ROS) and lowers the aconitase activity. Variations in UCP2 protein levels parallel those of ROS. Metformin also increases lipolysis in these cells although only when the levels of ROS and UCP2 have decreased. Hence, UCP2 does not appear to be needed to facilitate fatty acid oxidation. Furthermore, treatment of C57BL/6 mice with metformin also augmented the levels of UCP2 in epididymal white adipose tissue. We conclude that metformin treatment leads to the overexpression of UCP2 in adipocytes to minimize the oxidative stress that is probably due to the inhibition of respiration caused by the drug.

  1. 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.

  2. Increased Levels of Antinutritional and/or Defense Proteins Reduced the Protein Quality of a Disease-Resistant Soybean Cultivar.

    Science.gov (United States)

    Sousa, Daniele O B; Carvalho, Ana F U; Oliveira, José Tadeu A; Farias, Davi F; Castelar, Ivan; Oliveira, Henrique P; Vasconcelos, Ilka M

    2015-07-22

    The biochemical and nutritional attributes of two soybean (Glycine max (L.) Merr.) cultivars, one susceptible (Seridó) and the other resistant (Seridó-RCH) to stem canker, were examined to assess whether the resistance to pathogens was related to levels of antinutritional and/or defense proteins in the plant and subsequently affected the nutritional quality. Lectin, urease, trypsin inhibitor, peroxidase and chitinase activities were higher in the resistant cultivar. Growing rats were fed with isocaloric and isoproteic diets prepared with defatted raw soybean meals. Those on the Seridó-RCH diet showed the worst performance in terms of protein quality indicators. Based on regression analysis, lectin, trypsin inhibitor, peroxidase and chitinase appear to be involved in the resistance trait but also in the poorer nutritional quality of Seridó-RCH. Thus, the development of cultivars for disease resistance may lead to higher concentrations of antinutritional compounds, affecting the quality of soybean seeds. Further research that includes the assessment of more cultivars/genotypes is needed.

  3. Luciferase NanoLuc as a reporter for gene expression and protein levels in Saccharomyces cerevisiae.

    Science.gov (United States)

    Masser, Anna E; Kandasamy, Ganapathi; Kaimal, Jayasankar Mohanakrishnan; Andréasson, Claes

    2016-05-01

    Reporter proteins are essential tools in the study of biological processes and are employed to monitor changes in gene expression and protein levels. Luciferases are reporter proteins that enable rapid and highly sensitive detection with an outstanding dynamic range. Here we evaluated the usefulness of the 19 kDa luciferase NanoLuc (Nluc), derived from the deep sea shrimp Oplophorus gracilirostris, as a reporter protein in yeast. Cassettes with codon-optimized genes expressing yeast Nluc (yNluc) or its destabilized derivative yNlucPEST have been assembled in the context of the dominant drug resistance marker kanMX. The reporter proteins do not impair the growth of yeast cells and exhibit half-lives of 40 and 5 min, respectively. The commercial substrate Nano-Glo® is compatible with detection of yNluc bioluminescence in yeast using standard commercial substrate. © 2016 The Authors. Yeast published by John Wiley & Sons Ltd. © 2016 The Authors. Yeast published by John Wiley & Sons Ltd.

  4. Infrared analyzers for breast milk analysis: fat levels can influence the accuracy of protein measurements.

    Science.gov (United States)

    Kwan, Celia; Fusch, Gerhard; Bahonjic, Aldin; Rochow, Niels; Fusch, Christoph

    2017-10-26

    Currently, there is a growing interest in lacto-engineering in the neonatal intensive care unit, using infrared milk analyzers to rapidly measure the macronutrient content in breast milk before processing and feeding it to preterm infants. However, there is an overlap in the spectral information of different macronutrients, so they can potentially impact the robustness of the measurement. In this study, we investigate whether the measurement of protein is dependent on the levels of fat present while using an infrared milk analyzer. Breast milk samples (n=25) were measured for fat and protein content before and after being completely defatted by centrifugation, using chemical reference methods and near-infrared milk analyzer (Unity SpectraStar) with two different calibration algorithms provided by the manufacturer (released 2009 and 2015). While the protein content remained unchanged, as measured by elemental analysis, measurements by infrared milk analyzer show a difference in protein measurements dependent on fat content; high fat content can lead to falsely high protein content. This difference is less pronounced when measured using the more recent calibration algorithm. Milk analyzer users must be cautious of their devices' measurements, especially if they are changing the matrix of breast milk using more advanced lacto-engineering.

  5. Effect of nonsurgical periodontal treatment on C-reactive